publicationDate stringlengths 10 10 | abstract stringlengths 0 37.3k | title stringlengths 1 5.74k | doi stringlengths 11 47 ⌀ |
|---|---|---|---|
2023-04-01 | Thermal interface materials (TIMs) play a vital role in the thermal management of electronic devices and can significantly reduce thermal contact resistance (TCR). The TCR between the solid-liquid contact surface is much smaller than that of the solid-solid contact surface, but conventional solid-liquid phase change materials are likely to cause serious leakage. Therefore, this work has prepared a new form-stable phase change thermal interface material. Through the melt blending of paraffin wax (PW) and low-density polyethylene (LDPE), the stability is improved and it has an excellent coating effect on PW. The addition of aluminum (Al) powder improves the low thermal conductivity of PW/LDPE, and the addition of 15wt% Al powder improves the thermal conductivity of the internal structure of the matrix by 67%. In addition, the influence of the addition of Al powder on the internal structure, thermal properties, and phase change behavior of the PW/LDPE matrix was systematically studied. The results confirmed that the addition of Al powder improved the thermal conductivity of the material without a significant impact on other properties, and the thermal conductivity increased with the increase of Al addition. Therefore, morphologically stable PW/LDPE/Al is an important development direction for TIMs. | Emerging low-density polyethylene/paraffin wax/aluminum composite as a form-stable phase change thermal interface material | 10.1007/s12613-022-2565-6 |
2023-04-01 | The desiccant dehumidification system can separate the latent heat and sensible heat in the air-conditioning system and achieve energy savings by removing latent heat. Industrial waste heat and renewable energy could be utilized in desiccant dehumidification systems, where the desorption process can be performed below 70 °C. The vapor pressure and temperature of the regenerating air dictate the desorption process corresponding to the isotherm properties. This study has focused on the effects of various temperatures and humidity ratios of regeneration air on the performance of a desiccant dehumidifier using a polymer as an adsorbent. Experiments were performed using the regeneration air with the humidity ratios of 0.005 kg kg −1 , 0.010 kg kg −1 , 0.015 kg kg −1 , and 0.020 kg kg −1 , while the air temperatures were varied from 40 °C to 70 °C. The evaluation of this study employs the adsorption/desorption amount, average moisture removal capacity, and latent energy ratio (LER) of the regeneration process as key performance indexes. At the regeneration temperature of 68 °C, the peak desorption amount at the humidity ratio of 0.005 kg kg −1 and 0.010 kg kg −1 both reached 0.011 kg kg −1 . The results indicated that the higher desorption temperature led to a higher desorption amount. Besides, with the increased desorption temperature, the average moisture removal capacity increases. In contrast, the high humidity ratio of regeneration air resulted in a weak dehumidification ability. Lower regeneration temperature was difficult to apply to regenerate the polymer-based desiccant under a high-humidity-ratio atmosphere. To attain a high LER, a lower humidity ratio of dry air and regeneration temperature was preferred. The regeneration air with a humidity ratio of 0.020 kg kg −1 is not suitable to apply in the dehumidification system in the temperature range of 40–70 °C. | Effects of temperature and humidity ratio on the performance of desiccant dehumidification system under low-temperature regeneration | 10.1007/s10973-022-11368-7 |
2023-04-01 | Thermal drying makes cellulosic fibers shrink, resulting in pore collapse and degraded fiber performance. However, in this work, the pores of cellulose fibers expanded in the later stage of low-temperature thermal drying by regulating the fiber stacked structure before drying, which was called “low-temperature pore expansion effects”. The results showed a high content of lignin was required because there were no low-temperature pore expansion effects during the drying process of low lignin-containing cellulosic fibers. Three-dimensional fiber stacked structure was also necessary because cellulose fiber materials with two-dimensional stacked structure, such as paper, had no pore expansion effects. The pore expansion effects first strengthened and then weakened with increasing temperature, and the optimum temperature was 60 °C. According to the results, the pore expansion effects included the pore shrinkage period and pore expansion period. Finally, a possible lignin-cellulose phase separation mechanism was proposed to explain this phenomenon. This work reveals the special ultrastructural transformation of cellulosic fibers under low-temperature drying, providing a reference for precise regulation of the properties of dried fibers. | Low-temperature thermal drying-induced pore expansion effects of cellulosic fibers | 10.1007/s10570-023-05103-0 |
2023-04-01 | In this study, textured vegetable protein (TVP) based on soy protein isolate, wheat gluten, and corn starch was prepared at a 5:3:2 (w/w) ratio using a low-moisture extrusion process. To evaluate the effects of extrusion parameters, die temperature and screw rotation speed, on the properties of TVP, these two parameters were manipulated at a constant barrel temperature and moisture content. The results indicated that increasing the die temperature increased the expansion ratio while decreasing the density of the extrudates. Simultaneously, increasing the screw rotation speed clearly increased the specific mechanical energy of the TVP. Furthermore, mathematical modelling suggested that the expansion ratio increases exponentially to the die temperature. However, extreme process conditions bring about a decrease in water absorption capacity and expansion ratio, as well as undesirable texture and microstructure. The results suggested that the properties of SPI-based TVP are directly influenced by the extrusion process parameters, screw speed and die temperature. | Effect of screw speed and die temperature on physicochemical, textural, and morphological properties of soy protein isolate-based textured vegetable protein produced via a low-moisture extrusion | 10.1007/s10068-022-01207-8 |
2023-04-01 | Cold recycling method minimizes the need for aggregates while building roads and has significant economic and environmental benefits. The cold recycled mixture's inadequate mechanical strength, however, is a significant flaw. This article presents the strength increase equation after first analyzing the increasing law of the mechanical strength of the emulsified asphalt cold recycled mixture. The mechanical strength, high-temperature performance and low-temperature performance of emulsified asphalt cold recycled mixture have all been examined after the use of cement and fiber. The reinforcing effect of the fiber is also confirmed through field testing. Studies have shown that after 48 h, the mechanical properties of the emulsified asphalt cold recycled mixture become stable, and the increase is small. The correlation between the proposed strength growth equation and the laboratory test results reaches 0.99. With the addition of 1.5% cement, the high-temperature performance and low-temperature performance of asphalt mixture can be improved by 33% and 18%, respectively. The 0.4% of fiber can improve the high-temperature performance and low-temperature performance of asphalt mixture by 6% and 19%, respectively. Analyze the effect of cement and fiber on the performance of the emulsified asphalt cold recycled mixture, and choose the optimal content of cement and emulsified asphalt to be 1.5% and 0.4%, respectively. | Laboratory and Field Research on Using Cement and Polyester Fiber to Enhance the Performance of Emulsified Asphalt Cold Recycled Mixture | 10.1007/s13369-022-07260-z |
2023-04-01 | Abstract A low-temperature test bench is developed for studying the low-temperature wear of frictional pairs based on powder coatings. The tribological properties of frictional pairs at low temperature are analyzed. Their wear is studied. The temperature variation of a frictional pair in cold startup of a mechanism is determined. Laws describing coating and counterbody wear are derived. | Low-Temperature Behavior of a Frictional Pair: Powder Coating and Metal Counterbody | 10.3103/S1068798X23050258 |
2023-04-01 | Increased worldwide power consumption in the twenty-first century reflects industry progress and economic expansion. This increases the demand for electricity from power plants, which raises their operating conditions and parameters thus requiring high-performance steel to be used. P91 steel is the best selection material as it poses excellent thermal conductivity, low thermal expansion coefficient, and high corrosion resistance. However, the material component is exposed to mechanical and temperature cycling, which creates thermal gradients on the components and may generate high cyclic stress levels between the components, which may cause cracks in the structure of the components and body damage. Prolonged exposure of the material to cyclic loading may result in low-cycle fatigue which may cause thermo-mechanical fatigue failure to the components. The low-cycle fatigue test is costly and time- consuming. Therefore, the use of the finite element approach in material analysis can be helpful to examine the behavior of steel specimens when subjected to low-cycle fatigue. The cyclic stress–strain response was replicated by using the constitutive model of combination isotropic–kinematic hardening implemented in the finite element software Abaqus. The development of the material model for the numerical simulation is based on a previous study where the parameters for the experimental low-cycle fatigue tests were extracted to be used in the calculation for the simulation. The combined hardening parameters were developed, and the isotropic and kinematic hardening parameters were calculated. The simulation uses strain amplitude varying between 0.25 and 0.6% with a constant strain rate of 0.1%s-1 at room temperature. The stress amplitude of the material decreases as the number of cycles increases which shows that the material exhibits cyclic softening in cyclic loading. Cyclic softening behavior is more noticeable with higher strain amplitude as it resulted in lower fatigue life. Higher strain amplitude resulted in higher peak stress and plastic strain. The finite element analysis of the low-cycle-fatigue P91 steel is relatively like the experimental results which also can give a significant understanding of the usage of P91 steel to industrial applications. | Numerical Simulation of P91 Steel Under Low-Cycle-Fatigue Loading | 10.1007/s11668-022-01574-8 |
2023-04-01 | In Ethiopia, the agricultural residues Khat ( Catha edulis ) stem and peanut or groundnut ( Arachis hypogaea ) shell are dumped in large quantities as solid waste posing significant environmental problems. This study was aimed at utilizing a mixture of these agricultural residues by combination of carbonization and cold pelleting technique. Response surface methodology (RSM) statistical experimental design was used to optimize the carbonization condition. Carbonization temperature, time, and biomass mix composition expressed as percent by weight of peanut shell (w/w %) were selected as the experimental parameters. The calorific value and charcoal yield of carbonized samples were examined as experimental responses. Based on the analysis of variance, carbonization temperature and biomass mix ratio were found significant study parameters, which affected the calorific value as well as charcoal yield. The interaction effects of the selected parameters well fitted with the second-order quadratic model equation. The optimum values of the influencing parameters were found to be at carbonization temperature of 402 °C, carbonization time of 97 min, and mix composition of 70 w/w % for maximum calorific value of 25.28 MJ/kg and charcoal yield of 41.84%. Furthermore, the mixed carbonized biomass prepared at the optimum condition was used for pellet preparation using the molasses-enhanced cold pelletization process. Results show that the density, calorific value, and mechanical strength of the pellet samples were significantly improved due to the addition of molasses as a binder. | Statistical optimization of mixed peanut shell and Khat (Catha edulis) stem carbonization process for molasses enhanced cold and low-pressure pelletization | 10.1007/s13399-021-01446-5 |
2023-04-01 | The symbiosis between plants and arbuscular mycorrhizal (AM) fungi is usually beneficial to plant growth. However, the balance of resource exchange between plants and AM fungi can be modified by climatic conditions that affect plant and fungal functioning. In particular, atmospheric CO 2 and temperature have risen dramatically since the Last Glacial Maximum (LGM). The negative effects of subambient CO 2 and/or subambient temperature of the past relative to the present on plant growth and fungal functioning could have reduced both the capacity of plants to allocate carbon to AM fungi and inhibited the nutritional or other benefits plants obtain from the symbiosis. To investigate this hypothesis, we grew three plant species in a fully factorial experiment with and without AM fungi at ambient and subambient CO 2 and temperature conditions. We expected that plant growth responses to AM fungi would be highest at ambient CO 2 and temperature, lower at either subambient CO 2 or subambient temperature, and lowest in the combined subambient CO 2 and temperature treatment. In contrast, we found that the positive response of plant biomass to AM fungal inoculation was strongest when plants were exposed to subambient CO 2 or subambient temperature relative to ambient conditions. Therefore, the subambient CO 2 and/or subambient temperature conditions of the LGM may not necessarily have reduced plant responsiveness to AM fungi compared to the present climate. | Plant response to arbuscular mycorrhizal fungi at CO2 and temperature levels of the past and present | 10.1007/s13199-023-00906-y |
2023-04-01 | β-Ga 2 O 3 , with ultra-wide bandgap, high absorption coefficient for high-energy ultraviolet (UV) photons, and high structural stability toward harsh-environment, has been receiving persistent attention for deep ultraviolet photodetectors applications. However, realization of devices with high tolerance toward high temperature faces great challenges due to considerable background signals mainly arising from abundant thermal excited carrier. Herein, nanowire-mediated high-quality β-Ga 2 O 3 nanobelts with ultra-thin thickness and length up to several hundred micrometers were achieved via a simple catalyst-free chemical vapor deposition route. The resulted microdevice output superior optoelectric figure of merits among numerous reports about β-Ga 2 O 3 , i.e., ultra-low dark current (below the detection limit of 10 −12 A), high responsivity (1,320 A/W), and high spectral selectivity working under low voltage (∼ 2 V). More importantly, the performance remains robust at elevated temperature higher than 573 K. These results indicate a large prospect for low-voltage driven deep ultraviolet photodetectors with good sensitivity and stability at harsh environments. | Nanowires mediated growth of β-Ga2O3 nanobelts for high-temperature (> 573 K) solar-blind photodetectors | 10.1007/s12274-022-5243-0 |
2023-04-01 | The 0.9Mg 2 SiO 4 -0.1CaTiO 3 (MSCT) ceramics with 60ZnO-20B 2 O 3 -20SiO 2 glass (ZBS) and LiF compound additives were prepared by solid-state reaction method. The effects of different ZBS contents on the phase, densification temperature, surface morphology and dielectric properties of MSCT ceramics were studied. The results show that ZBS can inhibit the reaction between LiF and CaTiO 3 , which improve the surface morphology and reduce the sintering temperature of MSCT ceramics. The sample of MSCT with 2wt%ZBS-1.5wt%LiF sintered at 900 °C for 90 min shows excellent microwave dielectric properties: ε r = 9.26, Q × f = 68,580 GHz (at 15.5 GHz) and τ f = -1.49 ppm/ °C. There is no obvious element diffusion at the co-firing interface between dielectrics and Ag electrodes, indicating it is a promising candidate for LTCC applications. | Effects of ZBS addition on crystallization, microstructure and dielectric properties of low temperature co-fired Mg2SiO4-CaTiO3 ceramics | 10.1007/s10832-023-00303-3 |
2023-04-01 | Low-heat Portland cement has been extensively used in mass concrete because of its low hydration heat and high later strength. However, low-heat cement has characteristics of slow activity and low early strength, which affects its propagation and applications in mass concrete to a certain degree. Moreover, comprehensive theoretical research on the mechanical properties and constitutive relations of pure and modified low-heat cement concretes is lacking. In view of this, this study reviews the research progress of the mechanical properties and the damage theory of fiber-reinforced low-heat cement concrete based on analysis of the existing literature. First, the mineral composition, hydration mechanism, and performance characteristics of low-heat cement concrete are analyzed. Second, the performance traits of low-heat cement fiber concrete are examined, and the influence laws of basalt and brucite fibers on the mechanical properties of concrete are determined. Finally, the application of damage mechanics theory to fiber-reinforced concrete is summarized. This study shows that although fibers can effectively enhance the mechanical properties of low-heat cement concrete, there are limitations in the selection of fiber type. In addition, basalt and brucite fibers play significant roles in enhancing the mechanical properties of concrete; therefore, the objectives of this paper are to present the application prospects of fibers in low-heat cement concrete and propose a new concept of mixing fibers to boost the early mechanical properties of low-heat cement concrete. Combining theoretical research and analysis, it provides directions and concepts for applying the damage theory to low-heat fiber cement concrete in the future. | Review of Mechanical Properties and Damage Theory of Fiber-Reinforced Low-Heat Cement Concrete | 10.1007/s13369-022-07427-8 |
2023-04-01 | Abstract— Analysis of impact bending test results for a large number of specimens is used to investigate fracture of a weld metal consisting predominantly of acicular ferrite. The metal has a very broad ductile-to-brittle transition interval: from +20 to below –60°C. In the temperature range studied, we observe three stable impact toughness levels. Transitions between them with decreasing temperature determine the scatter in the work done to fracture the specimen. According to fractography results, the ductile-to-brittle transition is due to a single-step change from a ductile fracture mechanism to cleavage. Cleavage cracks nucleate at large acicular ferrite grains. Their different arrangements on a cleavage site determine the impact toughness level. Comparison of dynamic fracture curves and the macroscopic structure of fracture surfaces demonstrates that cleavage cracks nucleate at the tip of a stably growing ductile crack. Examination of fracture surfaces makes it possible to identify individual cleavage events observed in the corresponding dynamic curve. | Microstructure and Impact Toughness of Acicular Ferrite in Low Alloy Steel Weld Joints from Results of Multiple Impact Bending Tests | 10.1134/S0020168523040027 |
2023-04-01 | Applications of nanotechnology in several fields of petroleum industry, e.g., refinery, drilling and enhanced oil recovery (EOR), have attracted a lot of attention, recently. This research investigates the applications of nanoparticles in EOR process. The potential of various nanoparticles, in hybrid and bare forms for altering the state of wettability, reducing the interfacial tension (IFT), changing the viscosity and activation of other EOR mechanisms are studied based on recent findings. Focusing on EOR, hybrid applications of nanoparticles with surfactants, polymers, low-salinity phases and foams are discussed and their synergistic effects are evaluated. Also, activated EOR mechanisms are defined and specified. Since the stabilization of nanofluids in harsh conditions of reservoir is vital for EOR applications, different methods for stabilizing nanofluids through EOR procedures are reviewed. Besides, a discussion on different functional groups of NPs is represented. Later, an economic model for evaluation of EOR process is examined and “Hotelling” method as an appropriate model for investigation of economic aspects of EOR process is introduced in detail. The findings of this study can lead to better understanding of fundamental basis about efficiency of nanoparticles in EOR process, activated EOR mechanisms during application of nanoparticles, selection of appropriate nanoparticles, the methods of stabilizing and economic evaluation for EOR process with respect to costs and outcomes. | A review on application of nanoparticles for EOR purposes: history and current challenges | 10.1007/s13202-022-01606-x |
2023-04-01 | At present, the interest in applied and fundamental research in the field of condensed matter physics has shifted from bulk materials to nanoscale semiconductor structures. Of particular interest are the properties of the energy spectrum of charge carriers in low-dimensional semiconductor structures exposed to a quantizing magnetic field. Quantization of the energy levels of free electrons and holes in a quantizing magnetic field leads to a significant change in the form of oscillations of the density of energy states in two-dimensional semiconductor structures. Thus, in this manuscript, we investigated the effect of the temperature and thickness of the quantum well on the oscillations of the density of energy states in the conduction band of nanoscale semiconductor structures. A new mathematical model has been developed for calculating the temperature dependence of the oscillations of the density of states in a rectangular quantum well under the influence of a transverse quantizing magnetic field. Using the proposed model, the experimental results were explained at different temperatures and magnetic fields. | Modeling the temperature dependence of the density oscillation of energy states in two-dimensional electronic gases under the impact of a longitudinal and transversal quantum magnetic fields | 10.1007/s12648-022-02435-8 |
2023-04-01 | Free formaldehyde is a carcinogen whose emission reduction in particleboard has been studied recently to mitigate this environmental and human health problem. One alternative to reduce the emission of formaldehyde in particleboards is by using adhesives produced from natural sources. Cardanol-formaldehyde is an environmentally friendly adhesive made with cashew nut liquid, a byproduct from the cashew chain. This work aimed to produce particleboard using cardanol-formaldehyde in place of urea. In addition, different proportions of bean straw wastes were used to replace pine wood. The combination of eco-friendly adhesive and lignocellulosic waste particles could result in a product that meets market demands while being environmentally nonaggressive. Cardanol-formaldehyde promoted a higher modulus of elasticity (MOE) (1172 MPa) and modulus of rupture (MOR) (4.39 MPa) about panels glued with urea–formaldehyde, which presented a MOE of 764 MPa and MOR of 2.45 MPa. Furthermore, the cardanol-formaldehyde adhesive promoted a 93% reduction in formaldehyde emission, with a reduction from 16.76 to 1.09 mg/100 g oven-dry board for particleboards produced with cardanol-formaldehyde, indicating potential as an adhesive in the particleboard industry. | Cardanol-based adhesive with reduced formaldehyde emission to produce particleboards with waste from bean crops | 10.1007/s11356-023-25764-5 |
2023-04-01 | In the present study, an inexpensive adsorbent has been synthesized from waste sawdust which can remove the highly toxic dye indigo carmine (IC) from aqueous solution. Activated carbon from sawdust was synthesized using physical and chemical treatment. After using the adsorbent in batch-dye adsorption experiments, it has been characterized by SEM, FT-IR and XRD which showed significant up-taking capacity (77%) of the dye on its surface. Sensitivity of the dye removal process has been analysed by undergoing batch study with varying initial concentrations of the IC dye, adsorbent dose, pH and temperature and optimization of the process which indicated the optimum condition of the experimental parameters. Various isotherm models and kinetic models have been used for fitting of experimental data and examined to analyse efficiency of the adsorption mechanism. Langmuir isotherm and pseudo-second-order kinetics were found to be followed by adsorption process over the entire dataset of tested experimental results. The maximum uptake capacity was found to be 30 mg g −1 . Thermodynamic investigation was also conducted to project the spontaneity of the reaction. | Synthesis of activated carbon material using sawdust as precursor and its application for dye removal: batch study and optimization using response surface methodology | 10.1007/s13399-021-01385-1 |
2023-04-01 | In this pilot study, we analyzed the response of magnetic fabrics and X-ray diffraction to low strains (≤ 0.0103) applied during quasi-static and dynamic deformation. Four cylindrical samples of Maggia gneiss were deformed under uniaxial compression oriented parallel to the foliation of the gneiss. Out of these four, two cylinders were deformed at dynamic strain rates (> 50/s) with a split Hopkinson pressure bar and two at quasi-static strain rates (< 10 –4 /s) using a hydraulic press. From each deformed cylinder, five to six specimens were retrieved. Under the polarizing microscope, the original samples and those deformed in the laboratory do not show any difference in microstructures. However, X-ray diffraction reveals gradual straining of the quartz and biotite lattice with increasing experimental strain. Moreover, after the experimental deformation, the maximum and intermediate principal magnetic susceptibility axes ( K 1 and K 2 ) form a girdle, which is clearly different from the triaxial distribution in the undeformed samples. The corrected degree of anisotropy and the oblateness of the magnetic fabrics increase. The magnitude of the intermediate susceptibility axis ( K 2 ) increases, and of the minimum susceptibility axes ( K 3 ) decreases. In this pilot study, we are able to show that XRD and magnetic fabrics are very sensitive to strain and capable of recording even low strains which do not present any other apparent evidence of deformation. With further studies, XRD can be established as a practical technique for measuring low mechanical strain in rocks. | Use of magnetic fabrics and X-ray diffraction to reveal low strains in experimentally deformed Maggia gneiss | 10.1007/s00531-022-02284-0 |
2023-04-01 | The present study aims to produce sandwich composites with curved surfaces with different surface geometries by adding rubber (EPDM) between glass fiber woven fabrics and to examine their behavior under the influence of low-velocity impact numerically and experimentally. For this purpose, glass fiber and rubber layers were added to steel molds manufactured in curved forms and sandwich plates were produced through the vacuum infusion method. Low-velocity impact tests were performed by lowering strikers with a hemispherical tip on the produced curved-surface plates, and the effect of the surface geometry on the impact energy absorption was determined. By using rubber intermediate layers, the energy absorption ability can be increased by a maximum of 21%. The curved surface geometry affects the absorbed energy. If the height of the curved surface composites is kept constant and the width is increased to 1.5 times, the impact energy absorption increases by 16 percent. If the width is kept constant and the height is increased to 2.3 times, the impact energy absorption has decreased by 13 percent. When the impact resistance of composites with triangular rectangular, R125 circular arc and flat geometries with the same height and width are compared, it is observed that the lowest impact absorption ability occurs in the plates with triangular geometry, while the impact damping feature increases as the surface geometry becomes flatter and accordingly the contact surface increases. The impact absorption energies of the specimens were determined to be 82% compared to the flat plates. When the impact absorption energies of the upper side lengths of the outer tangent quadrilaterals to the R125 circle arc are compared, a significant increase in the impact absorption capabilities was observed as the side lengths increased. In the numerical part, the tests performed were modeled using the LS-DYNA finite element package program and the Hashin damage criterion-based MAT162 material model was used in order to see the damage caused to the composite structure in three dimensions after the tests. The numerical results obtained were a minimum of 84% compatible to the experimental results. | Experimental and Numerical Investigation of the Geometrical Effect on Low Velocity Impact Behavior for Curved Composites with a Rubber Interlayer | 10.1007/s10443-022-10094-5 |
2023-04-01 | Sapelli wood sawdust-derived magnetic activated carbon (SWSMAC) was produced by single-step pyrolysis using KOH and NiCl 2 as activating and magnetization agents. SWSMAC was characterized by several techniques (SEM/EDS, N 2 adsorption/desorption isotherms, FTIR, XRD, VSM, and pH PZC ) and applied in the brilliant blue FCF dye adsorption from an aqueous medium. The obtained SWSMAC was a mesoporous material and showed good textural properties. Metallic nanostructured Ni particles were observed. Also, SWSMAC exhibited ferromagnetic properties. In the adsorption experiments, adequate conditions were an adsorbent dosage of 0.75 g L −1 and a solution pH of 4. The adsorption was fast, and the pseudo-second-order demonstrated greater suitability to the kinetic data. The Sips model fitted the equilibrium data well, and the maximum adsorption capacity predicted by this model was 105.88 mg g −1 (at 55 °C). The thermodynamic study revealed that the adsorption was spontaneous, favorable, and endothermic. Besides, the mechanistic elucidation suggested that electrostatic interactions, hydrogen bonding, π–π interactions, and n–π interactions were involved in the brilliant blue FCF dye adsorption onto SWSMAC. In summary, an advanced adsorbent material was developed from waste by single-step pyrolysis, and this material effectively adsorbs brilliant blue FCF dye. | Brilliant blue FCF dye adsorption using magnetic activated carbon from Sapelli wood sawdust | 10.1007/s11356-023-26646-6 |
2023-04-01 | Wire arc additive manufacturing (WAAM) is a layer-by-layer fabrication technique that enables the manufacture of large-scale parts at a higher efficiency. Multi bead depositions cause heat buildup, which rises the temperature of the previously deposited layer during WAAM. This causes process instabilities, resulting in variations from the required dimension and material property changes. In this research, the interlayer delay was increased from 40 to 120 s during the deposition of the low carbon steel walls. The effect of interlayer delay on bead height, width, hardness and microstructure were examined. It was observed that the temperature was reduced with an increase in interlayer delay, leading to a variation in wall height, width, hardness and microstructure. The wall width was decreased and the height of the wall was increased with an increase in the interlayer dwell time from 40 to 120 s. The hardness of the deposited parts was increased with an increase in interlayer delay due to fine grain microstructure. By changing the interlayer delay time, the study points the way toward tailoring the characteristics of low carbon steel wall structures made using wire arc additive manufacturing. | Effect of interlayer delay on microstructure and bead geometry of wire arc additive manufactured low carbon steel components | 10.1007/s12008-022-01009-6 |
2023-04-01 | Abstract Hydroxylclinohumite Mg 5 (SiO 4 ) 2 (OH,F) 2 is a common monoclinic orthosilicate of the humite group, which, on the one hand, is a prototype of promising materials, and, on the other hand, is an important source of information about both the transport and the presence of water in the Earth’s mantle, and therefore studying its thermal behavior is of particular interest. In this paper, the mineral is studied by powder X-ray diffraction for the first time in a wide temperature range (–180 ≤ T ≤ 1000°C). The temperature limits for the existence of the phase are established, the principal values of the thermal expansion tensor are calculated, and a structural interpretation of thermal expansion is given. | Thermal Behavior (–180 ≤ T ≤ 1000°C) of Magnesium Orthosilicate Hydroxylclinohumite Mg5(SiO4)2(OH,F)2 | 10.1134/S1087659622601113 |
2023-04-01 | Using fast multiple rotation rolling (FMRR), a nanostructure layer was fabricated on the surface of Ti6Al4V alloy. The microstructure of the surface layer was investigated using optical microscopy, transmission electron microscopy, scanning electron microscopy, and X-ray diffraction. The results indicated that a nanostructured layer, with an average grain size of 72–83 nm, was obtained in the top surface layer, when the FMRR duration was 15 min. And the average grain size further reduced to 24–37 nm when the treatment duration increased to 45 min. High density dislocations, twins, and stacking faults were observed in the top surface layer. The microhardness of FMRR specimen, compared with original specimen, was significantly increased. A uniform, continuous and thicker compound layer was obtained in the top surface of FMRR sample, and the diffusion speed of N atom in the top surface layer was accelerated. FMRR treatment provides corrosion improvement. 采用快速多重旋转碾压技术（FMRR）在Ti6Al4V钛合金表面制备了纳米结构层。利用光学显微镜术、透射电子显微镜术、扫描电子显微镜术、X射线衍射等方法对表层组织结构进行分析。结果表明，当FMRR处理时间为15 min时，在表层获得纳米层，平均晶粒尺寸为72~83 nm。当FMRR处理时间增加到45 min时，晶粒得到进一步细化，平均晶粒尺寸为24~37 nm。在表层发现高密度位错、孪晶和层错等结构缺陷。与原始试样相比，FMRR处理后试样的显微硬度显著增加。在FMRR处理后的试样表层得到了均匀、连续并具有一定厚度的化合物层，同时表层N原子的扩散速度增加。FMRR处理改善了基体的耐蚀性。 | Effect of Fast Multiple Rotation Rolling on Microstructure and Properties of Ti6Al4V Alloy | 10.1007/s12204-021-2395-0 |
2023-04-01 | In their 2013 paper, Lenz et al. illustrated how trees growing at the low-temperature limit respond to a chronic in situ warming or cooling by 3 K, by employing Peltier-thermostated branch collars that tracked ambient temperatures. The micro-coring-based analysis of seasonal tree ring formation included double-staining microtome cross sections for lignification, but these data had not been included in the publication. In this short communication, we complement these data, collected in 2009 at the Swiss treeline, and we show that a 3 K cooling that corresponds to a 500–600 m higher elevation, had no influence on lignification. However, when a frost event occurred during the early part of ring formation, the 3 K cooling produced a blue (non-lignified) layer of cells, followed by normally lignified cells for the rest of the season. Hence, the event did not affect the cambium, but interrupted cell wall maturation in cells that were in a critical developmental stage. We conclude, that chronic cooling does not affect lignification at treeline, but it increases the risk of frost damage in premature xylem tissue. | Chronic in situ tissue cooling does not reduce lignification at the Swiss treeline but enhances the risk of ‘blue’ frost rings | 10.1007/s00035-023-00293-6 |
2023-04-01 | In the current study, three different combinations of dual-phase (DP) steels,i.e., ferrite–pearlite, ferrite–bainite, and ferrite–martensite containing the nearly same amount of second phase/phase mixture, have been developed following suitable heat-treatment schedules using a low carbon steel. Tensile and strain-controlled low cycle fatigue (LCF) tests at different strain amplitudes have been performed to understand the role of microstructure on the static and cyclic plasticity characteristics of DP steels. The experimental results reveal wide variations in the nature of cyclic hardening–softening behavior depending on the nature of the second phase. For the isotropic hardening, a new formulation considering the variation of yield stress as a function of memory stress and accumulated plastic strain has been incorporated, and Ohno–Wang kinematic hardening model has been used to simulate the observed fatigue response of DP structures. The developed model is capable of predicting the fatigue characteristics such as the stress amplitude versus the number of cycles, maximum hardening stress, and the progressive hysteresis loops. Further, the LCF simulations have been performed for the developed DP steels based on the real microstructure-based models adopting a sub-modeling technique. The stress and strain levels at different phases in the DP steels and their influence on the fatigue properties are quantified and discussed. | Predicting Macro- and Microscopic Responses of Dual-Phase Steels under Low Cycle Fatigue Based on Multi-scale Finite Element Methods | 10.1007/s11665-022-07298-y |
2023-04-01 | Low density, fire resistance and good thermal insulation properties of lightweight aggregate concrete (LWAC) have drawn the attention of engineers and researchers for its widespread application. However, the LWAC still found limited application in the construction industry. For conventional application of LWAC, knowledge of different attributes of its behaviour is needed, and thus the presented review investigates the comprehensive studies on LWACs incorporating lightweight aggregates (LWAs) i.e. oil palm shell, lightweight expanded clay aggregate (LECA), fly ash-sintered (FS) and pumice, along with supplementary cementitious materials (SCMs). Firstly, the physico-chemical, morphological and mineralogical characterization of different LWAs is presented, followed by critical review on fresh, hardened, durability and thermal properties of LWACs vis-a-vis normal weight concrete. Furthermore, research works conducted on the development of LWACs using LECA, fly ash and micro-fine slurry powder (MSP) are discussed. Research findings show that LWAC prepared with LECA as coarse and fine aggregate along with 25% fly ash + 10% MSP as cement replacement exhibits good mechanical and thermal properties. Overall, it has been envisaged that LWACs, because of their techno-economic and environmental advantages, are supposed to capture a major share in the building industry in the twenty first century. Basically, the scientific contribution of the present work is to provide the knowledge base and scientific basis for further research in this area and lay the foundation for the development of the guidelines to use LWACs. Graphical abstract | Influence of Lightweight Aggregates and Supplementary Cementitious Materials on the Properties of Lightweight Aggregate Concretes | 10.1007/s40996-022-00935-5 |
2023-04-01 | Here, statistics descriptive and inferential were employed to understand the acquired data from the process output variables such as porosity percentage, thickness, and deposition efficiency of the obtained coatings as a function of process input variables such as nozzle type, standoff distance, and the particle in-flight velocity before impact on the substrate. Coatings were produced by the LPCS process with copper powder deposited onto aluminum 6061 substrates, using two different nozzle shapes (rectangular and round) and two standoff distances (SOD) of 12.5 and 22.5 mm. It was found that nozzle type is the process input parameter with the most substantial contribution to the final coating properties. Particle in-flight velocity decreased by 38% at the standoff distance of 22.5 mm with the rectangular nozzle shape. In contrast, at the same standoff distance for the round nozzle shape, the in-flight particle velocity only diminished by 15%. The rectangular nozzle exhibits the uppermost change of in-flight particle velocity, impacting the particles at a very high speed. This could cause a high percentage of rebounded particles, diminishing the thickness and increasing the porosity percent. It was concluded that the round nozzle type is recommended to achieve coatings with low porosity levels without deep dependence on the standoff distance. This conclusion applies to the experimental conditions of this study with the given geometrical nozzle features. | A correlational study of process parameters on properties of low-pressure cold sprayed copper coatings | 10.1007/s00170-023-10976-3 |
2023-04-01 | This research work involves surface anionization of non-ionic polyester (PET- polyethylene terephthalate) fabric through a novel and facile modification technique to facilitate cationic dyeing, particularly basic dyeing under normal atmospheric conditions, instead of traditional sophisticated non-ionic disperse dyeing. Initially, the modification of PET with differently prepared modifiers was performed at 50 °C which introduced an anionic carboxylate group (COO − ) on its surface to promote effective bond formation with cationic basic dyes. The modification process did not alter the inherent mechanical properties, i.e., strength and elongation of the PET fabric. Subsequently, the basic dyeing of the sample was carried out at a lower temperature (50–60 °C) for 60 min. The dyeing of the modified PET fabric with modifier 1 at 60 °C yielded the best output for the basic blue 2GL dye in terms of color properties and shade quality. For modifier 2, the color output after dyeing at 50 °C was off shade and only a reddish tone appeared, but the color strength ( K/S ) and the evenness of the shade were satisfactory. Both modifiers significantly improved the color fastness properties of the dyed fabric in the range of very good (4) to excellent (4/5) fastness rating, while the unmodified fabric had a comparatively lower fastness grade (3). | Surface Modification of Non-Ionic Polyester Fabric into an Anionic Platform for Low Temperature Cationic Basic Dyeing with Improved Colorfastness Properties | 10.1007/s12221-023-00146-3 |
2023-04-01 | Samples were taken from the four main stressed parts of low-silicon cast aluminum alloy steering knuckle castings; their compositions and properties were tested. Microstructure observation and SEM and EDS analysis were performed on the samples, and Image Pro Plus was used to calculate the area fraction of inclusions at each position. The filling and solidification process of casting were simulated for aiding the analysis of inclusion formation. The main purpose of this research is to clarify the formation rules of inclusions in different positions of aluminum alloy castings and take corresponding measures to avoid the occurrence of inclusions, which plays an extremely important role in improving the quality of castings. The results showed that the castings mainly contain oxides such as Al 2 O 3 , MgO, SiO 2 and a small amount of Fe-containing intermetallic compounds. Moreover, the inclusions are affected by the flow rate and cooling rate of the liquid aluminum, and more inclusions are produced above the casting or in the region where the casting wall is thicker. | Investigation into the Formation of Inclusions in a Steering Knuckle Casting of Low-Silicon Cast Aluminum Alloy | 10.1007/s40962-022-00846-1 |
2023-04-01 | The microstructure and mechanical properties of 20MnCr5 low alloy steel fabricated using Laser-based powder bed fusion (PBF-LB) have been investigated. 20MnCr5 steel, which has been traditionally fabricated through forging followed by heat treatment has been successfully produced using PBF-LB by optimizing process parameters in the present study. The microstructure consisted of full martensite, exhibiting alternating tempered and non-tempered regions. The effect of laser power on the microstructure and mechanical properties was analyzed. The results showed that the 20MnCr5 steel’s microstructure, namely its pore distribution, melt pool size, martensite block, and lath sizes, and the volume of the tempered region varied by laser power. Each of these characteristics was positively correlated with laser power. This result was due to the difference in cooling rate according to laser power. These microstructural characteristics affected the steel’s mechanical properties. The yield strength (σ-y) of 1,054–1,096 MPa, ultimate tensile strength (UTS) of 1,126–1,208 MPa and fracture elongation (ε-f) of 10.7%–17.4%. Laser power was positively correlated with both yield strength and ultimate tensile strength, and negatively correlated with fracture elongation. This study showed that 20MnCr5 low alloy steel’s mechanical properties can be effectively controlled when producing it using PBF-LB and the optimal process parameters. Graphical abstract | Effect of Laser Power on the Microstructure Evolution and Mechanical Properties of 20MnCr5 Low Alloy Steel Produced by Laser-Based Powder Bed Fusion | 10.1007/s12540-022-01294-6 |
2023-04-01 | High-voltage medium-nickel low-cobalt lithium layered oxide cathode materials are becoming a popular development route for high-energy lithium-ion batteries due to their relatively high capacity, low cost, and improved safety. Unfortunately, capacity fading derived from surface lithium residue, electrode-electrolyte interfacial side reactions, and bulk structure degradation severely limits large-scale commercial utilization. In this work, an ultrathin and uniform NASICON-type Li 3 V 2 (PO 4 ) 3 (LVP) nanoscale functional coating is formed in situ by utilizing residual lithium to enhance the lithium storage performance of LiNi 0.6 Co 0.05 Mn 0.35 O 2 (NCM) cathode. The GITT and ex-situ EIS and XPS demonstrate exceptional Li + diffusion and conductivity and attenuated interfacial side reactions, improving the electrode-electrolyte interface stability. The variable temperature in-situ XRD demonstrates delayed phase transition temperature to improve thermal stability. The battery in-situ XRD displays the single-phase H1–H2 reaction and weakened harmful H3 phase transition, minimizing the bulk mechanical degradation. These improvements are attributed to the removal of surface residual lithium and the formation of NASICON-type Li 3 V 2 (PO 4 ) 3 functional coatings with stable structure and high ionic and electronic conductivity. Consequently, the obtained NCM@LVP delivers a higher capacity retention rate (97.1% vs. 79.6%) after 150 cycles and a superior rate capacity (87 mAh·g −1 vs. 58 mAh·g −1 ) at a 5 C current density than the pristine NCM under a high cut-off voltage of 4.5 V. This work suggests a clever way to utilize residual lithium to form functional coatings in situ to improve the lithium storage performance of high-voltage medium-nickel low-cobalt cathode materials. | Stabilization of high-voltage layered oxide cathode by utilizing residual lithium to form NASICON-type nanoscale functional coating | 10.1007/s12274-022-5298-y |
2023-04-01 | Abstract A universal method “Break upon Impact and in Static Conditions” (BIS) has been developed for the experimental determination of the ultimate strength properties of polymer composite materials based on multifilament nanocrystalline ultrahigh molecular weight polyethylene (UHMWPE) fibers, which differs in the method of fixing the sample in a testing machine. The method is carried out using a uniform BIS sample with an intermediate matrix at the ends and equipment for its attachment to the platforms of testing machines. The sample is a round composite rod composed of the fibers and matrices under investigation, which is held in the tooling by an additional matrix that fixes it under various loading rates. The BIS method was used to study the properties and mechanisms of destruction upon impact and in a static situation of anisotropic polymer and hybrid composite materials (PCM and HCM) based on flexible and rigid matrices reinforced with hybrid fibers of carbon, aramid, and UHMWPE fibers activated by nonequilibrium low-temperature plasma. The breaking loads under low-velocity impact and static bending conditions, relative deformation, specific absorbed-in-fracture energy, work of adhesion, shear strength, and other properties are determined. It was found out that the plasticity of the matrix and the hybrid fiber composition affect the properties and fracture mode of PCM and HCM. For the destruction of HCM with a flexible matrix upon impact, a load is required by a factor of two larger as for composites with a rigid matrix. HCMs have the highest strength, in which at all stages of loading up to failure joint deformation of the matrix and the reinforcing fiber occurs. The mechanism of deformation and destruction of anisotropic HCM upon impact is stepwise, while the nature of the deformation curve is zigzag. In static conditions, the deformation proceeds smoothly. By changing the ratio of carbon and UHMWPE fibers during hybridization, it is possible to control the properties of HCM and improve its specific properties. The combination of carbon and UHMWPE fibers in a hybrid fiber for reinforcing a flexible matrix makes it possible to create a material with a delayed fracture. It has been established that, for HCM based on a flexible matrix reinforced with a hybrid fiber combining 20% carbon and 80% UHMWPE fiber, the fracture load increases by a factor of 2, the specific fracture work (absorbed-in-fracture energy) increases by 42%, and relative deformation increases by 68%. | Influence of Rigid and Flexible Matrices on Ultimate Strength and Fracture Mechanisms of Polymer Composite Materials upon Impact and in Static Loading Conditions | 10.1134/S2075113323020296 |
2023-04-01 | Soft elastomers with mechanical properties similar to biological tissues have shown encouraging potential in applications of biomedical devices and stretchable electronics. With the ability to enhance electric and thermal conductivity, embedding low melting alloys into soft elastomer matrix has received considerable attention in recent years. However, the mechanical properties, especially the fatigue behaviors of these soft composites, have not been extensively investigated. Here, we fabricate two silicone elastomers filled with eutectic gallium-indium, a liquid metal alloy, which has a melting temperature around room temperature. The cyclic loading–unloading tests are first performed on the composites with low melting alloys in either solid or fluid state. The results show that the modulus and energy dissipation density of the composite increase with the ratio of the alloys when the deformation temperature is below the melting temperature, while these properties decrease with the ratio of alloys when they are in the fluid state. In contrast, the failure strain shows an opposite trend. Mechanical tests are further performed on specimens with a precut to measure the fracture energy and fatigue threshold. It is demonstrated that both fracture energy and fatigue threshold are significantly enhanced in the presence of low melting alloys regardless of their states. Finally, we apply a continuum damage model to describe the Mullins effect of the soft composites observed in the loading–unloading cycles, which further reveals the change of mechanical properties with deformation for different compositions of soft composites. | Mechanical Behaviors of Soft Elastomers Filled with Low Melting Alloys | 10.1007/s10338-022-00372-x |
2023-04-01 | Refrigeration plays a vital role in ensuring quality and safety of seafood. In a tropical country like India, the seafood industry has a relatively larger cooling load throughout the supply chain due to higher temperature differences between ambient and chilled seafood. The cooling demands in a seafood processing plant are typically at four different temperature levels. Supply of chilled water at 2 °C, ice at − 5 °C, cold storage maintained at − 25 °C, and a plate or blast freezer at − 40 °C. Commonly, a multi-evaporator multi-stage refrigeration system with refrigerants like R22, R404A, or NH 3 are used in India. However, R22 and R404A have harmful effects on the environment due to their high global warming potential. This study proposed an all-natural multi-evaporator CO 2 –NH 3 cascade refrigeration system (CRS). For comparison, the refrigeration demands in a surimi (seafood) processing and storage plant located in Mumbai were utilized. The study revealed that CO 2 –NH 3 CRS has the highest COP and the lowest annual energy consumption followed by conventional NH 3 system. CO 2 –NH 3 CRS exhibited 6.2%, 12.3% and 3.2% less energy consumption compared to R22, R404A, and NH 3 systems, respectively. Similarly, CO 2 –NH 3 CRS also showed the lowest total equivalent warming impact which is 26.8%, 44.3% and 3.2% less compared to R22, R404A, and NH 3 systems, respectively. Furthermore, CO 2 –NH 3 CRS also presented relatively better results in terms of annual cost rate and life cycle cost. | Energetic, environmental and economic assessment of multi-evaporator CO2–NH3 cascade refrigeration system for seafood application | 10.1007/s10973-022-11619-7 |
2023-04-01 | The overall safety of anchorage engineering is jeopardized by the corrosion failure of low-carbon steel anchor bolts in a complicated geotechnical environment. To research the corrosion behaviour of low-carbon steel anchor bolts in carbonaceous mudstone slopes and to reveal the corrosion characteristics and mechanism of low-carbon steel anchor bolts under different corrosion time, solution corrosion, electrochemical corrosion and microscopic tests of low-carbon steel anchor bolts were carried out using a carbonaceous mudstone soaking solution and low-carbon steel anchor bolts as corrosion specimens. The results show that the low-carbon steel anchor bolts undergo obvious electrochemical corrosion in the carbonaceous mudstone environment. The corrosion product colour gradually deepened and the corrosion area gradually increased with increasing corrosion time. In the early stage of corrosion (0–10 d), the corrosion rate per unit area rapidly increased, and a thin oxide layer formed on the surface of the low-carbon steel anchor bolts. However, with the oxidation of Fe ions on the surface of the low-carbon steel anchor bolt body, the oxide film was gradually destroyed, resulting in the accumulation of corrosion products on the entire low-carbon steel anchor bolt surface. At this time, the entire reaction process was dominated by charge transfer and substance transfer. 复杂岩土环境下低碳钢锚杆的腐蚀破坏对锚固工程的整体安全性具有极大威胁。为研究炭质泥岩边坡中低碳钢锚杆的腐蚀行为和揭示不同腐蚀时间下低碳钢锚杆的腐蚀特性与机理, 以炭质泥岩浸泡得到的液体为腐蚀溶液, 低碳钢锚杆为腐蚀试件, 开展溶液腐蚀、电化学腐蚀及微观试验。结果表明, 炭质泥岩环境下低碳钢锚杆产生明显的电化学腐蚀, 随着腐蚀时间的延长, 腐蚀产物的颜色逐渐加深, 腐蚀面积逐渐增大。在腐蚀初期(0~10 d), 单位面积腐蚀速率迅速加快, 低碳钢锚杆表面会形成一层薄的氧化膜, 随着低碳钢锚杆表面的Fe 离子被氧化, 氧化膜逐渐被破坏, 导致腐蚀产物在低碳钢锚杆表面堆积, 整个反应过程由电荷转移和物质转移共同主导。 | Corrosion characteristics of low-carbon steel anchor bolts in a carbonaceous mudstone environment | 10.1007/s11771-023-5296-6 |
2023-04-01 | With the development of integrate circuit and artificial intelligence, many kinds of transistors have been invented. In recent years, wide attention has been paid to the oxide thin film transistors due to its ease preparation, low cost, and suitability for mass production. Traditionally used gate dielectric film (such as silicon dioxide film) in oxide thin film transistor owns low dielectric constant, which leads to weak capacitive coupling between the gate dielectric layer and the channel layer. As a result, high voltage (10 V or more) needs to be applied on the gate electrode in order to achieve the purpose of regulating the current of channel layer. Therefore, new oxide thin film needs to be developed. In this work, silane coupling agents (3-triethoxysilypropyla-mine) KH550 solid electrolyte film was obtained by spin coating-process. The KH550 solid electrolyte was used as gate dielectric layer to fabricate low-voltage indium zinc oxide thin film transistor. The surface topography and thickness of KH550 solid electrolyte film were characterized by atomic force microscope and field emission scanning electron microscope, respectively. The capacitance-frequency curve of the sample was measured by impedance analyzer (Soloartron 1260A), and the electrical characteristics of the sample were analyzed by a semiconductor parameter analyzer (Keithley 4200 SCS). A maximum specific capacitance of about 7.3 µF/cm 2 is obtained at 1 Hz. The transistor shows a good stability of pulse operation and negative bias voltage, the operation voltage is only 2 V, the current on/off ratio is about 1.24 × 10 6 , and the subthreshold swing is 169.2 mV/dec. The development of KH550 solid electrolyte gate dielectric provides a novel way for the research of oxide thin film transistor. 随着集成电路和人工智能的发展，发明了各种各样的晶体管。近年来，氧化薄膜晶体管因其易于制备、成本低、适合批量生产而受到广泛关注。氧化物薄膜晶体管中传统使用的栅介质膜(如二氧化硅膜)介电常数较低，导致栅介质层与沟道层之间的电容耦合较弱。为了达到调节沟道层电流的目的，需要在栅电极上施加高电压(10 V或更高)，因此需要开发新型氧化物薄膜。采用旋涂法在氧化铟锡玻璃表面制备了硅烷偶联剂（γ-氨丙基三乙氧基硅烷）KH550固态电解质薄膜，以此为栅介质制备了氧化铟锌薄膜晶体管。利用原子力显微镜和扫描电子显微镜对KH550薄膜的表面形貌和厚度进行表征；使用阻抗分析仪测试了样品的电容-频率曲线；通过半导体参数仪分析了器件的电学特性。结果表明，频率为1 Hz时的单位面积电容达7.3 µF/cm 2 ，晶体管的工作电压为2 V、开关比1.24×10 6 、亚阈值摆幅169.2 mV/dec、场效应迁移率2.1 cm 2 /(V·s)，其脉冲工作稳定性和负偏压稳定性良好。KH550固态栅介质的开发研究为氧化物薄膜晶体管栅介质的研究提供了一种新的方向和思路。 | Low Voltage Indium-Oxide-Zinc Thin Film Transistor Gated by KH550 Solid Electrolyte | 10.1007/s12204-022-2421-x |
2023-04-01 | Highly dynamic induction motor drives require converter-driven low-inertia induction machines, which are continuously operated with high torque dynamics to accelerate and brake linear or rotating masses in a highly dynamic manner. However, every rapid change in the torque requires a correspondingly rapid change in the rotor current, which leads to the excitation of the transient skin effect in the massive rotor bars of squirrel cage motors. The additional eddy current losses resulting from the transient skin effect can cause overheating problems, especially in the case of deep rotor bars with fast load cycles. This paper is intended to show the reader how the additional rotor losses caused by the transient skin effect can be reduced through the design optimization procedure. At the same time, the other operating characteristics of the induction motor drive are not impaired. In addition, the moment of inertia of the drive motor can also be reduced as another optimization target by the multi-objective optimization process. As the underlying optimization algorithm, the differential evolution and the particle swarm optimization are implemented and compared with each other in order to verify the correctness of the optimization results. During the whole optimization work, great importance is attached to the interdisciplinary calculation method so that the interaction between the electromagnetic, thermal, fluid mechanical and control engineering processes can be taken into account through the coupled calculation. In the end, the theoretical and simulative findings are verified with two test benches. | Transient skin effect in highly dynamic induction motor drives: energy-optimized design | 10.1007/s00202-022-01712-3 |
2023-04-01 | Wire arc additive manufacturing (WAAM) has recently gained great attention in producing metallic parts due to significant cost savings, high deposition, and its convenience. However, there is still limited knowledge concerning testing for mechanical properties of the WAAM-produced steel parts using different welding wires. This paper presents the results of the extensive experimental study aimed at assessing the mechanical properties of the WAAM-produced multi-pass thick-walled steel parts using two different ER70S-6 and one ER110S-G welding wires. This study focused on revealing the role of the microstructure on the fracture toughness values, which were obtained from the specimens extracted in two directions, namely, transversal direction (T) and longitudinal direction (L) according to the deposition direction. Before extraction of the toughness specimens, the computed radiography (CR) tests were performed to detect if any welding defects occurred during the layer deposition. Next, the microstructural features of the thick-walled WAAM parts were characterized by stereo microscopy (SM), optical microscopy (OM), and scanning electron microscopy (SEM). Finally, the mechanical properties of the part were evaluated by Charpy V-notch (CVN) impact toughness, tensile, and hardness tests. The results exhibit an anisotropic material behavior in as-built conditions for each filler metal. Therefore, careful consideration of notch orientations and their effects on mechanical properties is important in assessing the fitness-for-service performance of the WAAM-produced low-alloyed steel parts. | Characterization and fracture toughness evaluation of the thick-walled wire arc additively manufactured low alloy steels | 10.1007/s40194-022-01424-z |
2023-04-01 | Background To evaluate the efficacy and safety of novel plasma radio frequency generator and its single-use polypectomy snares for endoscopic mucosal resection (EMR) of gastrointestinal (GI) polyps. Methods A total of 217 patients with 413 GI polyps were recruited from four centers in China. Patients were assigned to experimental or control groups using a central randomization method. The experimental group used the novel plasma radio frequency generator and its matched single-use polypectomy snares (Neowing, Shanghai), while the control group used the high-frequency electrosurgical unit (Erbe, Germany) and disposable electrosurgical snares (Olympus, Japan). The primary endpoint was the en bloc resection rate, and the non-inferiority margin was set at 10%. Secondary endpoint included operation time, coagulation success rate, intraoperative and postoperative bleeding rate, and perforation rate. Results The en bloc resection rate was 97.20% (104/107) in the experimental group and 95.45% (105/110) in the control group ( P = 0.496). The operation time was 29.14 ± 20.21 min in the experimental group and 30.26 ± 18.74 min in the control group ( P = 0.671). The average removal time of a single polyp in the experimental group was 7.52 ± 4.45 min, which was slightly shorter than that in the control group 8.90 ± 6.67 min, with no statistical difference ( P = 0.076). The intraoperative bleeding rates of the experimental group and control group were 8.41% (9/107) and 10.00% (11/110), respectively ( P = 0.686). No intraoperative perforation occurred in either group. The postoperative bleeding rates of the experimental group and the control group were 1.87% (2/107) and 4.55% (5/110), respectively ( P = 0.465). No postoperative perforation occurred in the experimental group (0/107), while one case of delayed perforation occurred in the control group (1/110, 0.91%). There was no statistical difference between the two groups. Conclusions Endoscopic mucosal resection of GI polyps with the novel plasma radio frequency generator is safe and effective, and non-inferior to the conventional high-frequency electrosurgical system. Graphical abstract | Endoscopic mucosal resection of gastrointestinal polyps with a novel low-temperature plasma radio frequency generator: a non-inferiority multi-center randomized control study | 10.1007/s00464-023-09945-4 |
2023-04-01 | To enable rapid recovery of a steel bridge column after an earthquake, a novel tubular-section steel bridge column equipped with low-yield-point (LYP) steel tubular plates in the root replaceable pier is proposed. For the purpose of discussing the seismic behavior of the novel steel bridge column, quasi-static tests and finite element simulation analyses of the specimens were carried out. The effects of parameters such as the axial compression ratio, eccentricity, and thickness and material strength of the tubular plate in the energy-dissipating zone are discussed. Experimental results from seven specimens that were subjected to four failure modes are presented. The damage to the quasi-static specimens is localized to the replaceable energy-dissipating pier. The seismic behavior of the novel steel bridge columns is significantly influenced by the axial compression ratio and eccentricity of specimens. Numerical results show that the high stress area of the specimens is mainly concentrated in the connection zone between the LYP steel tubular plate and the bottom steel plate, which is consistent with the position of the quasi-static specimen when it was prone to fracture. Finally, a calculation formula is proposed to facilitate the capacity prediction of this new steel tubular bridge column under repeated loading. | Seismic behavior of steel tubular bridge columns equipped with low-yield-point steel plates in the root replaceable pier | 10.1007/s11803-023-2182-z |
2023-04-01 | Over the last century, abnormal electromagnetic (EM) emissions associated with earthquake (EQ) activities have been widely reported and recorded by ground-based and satellite observations. However, the frequency at which abnormal EM emissions have been detected varies. In addition, whether low Earth orbit (LEO) satellites can detect EM anomalies from EQs remains controversial. In this paper, we take the Yushu earthquake as an example to address these concerns by DEMETER satellite observations and a newly constructed lithosphere-atmosphere-ionosphere model of extremely low frequency (ELF) wave propagation. The results illustrate that the frequency of ELF EM anomalies of the Yushu earthquake is mainly at 200–400 Hz. The observations and simulations illustrate that the power-frequency curve of the ELF EM wave from an underground source has a peak power frequency at 200–400 Hz, which is significantly different from the ELF EM wave radiated from the ground source. | Detecting seismic electromagnetic ELF anomalies associated with the 2010 Yushu earthquake in China by DEMETER observations and ELF Lithosphere-Atmosphere-Ionosphere coupling propagating model | 10.1007/s11431-022-2164-7 |
2023-04-01 | Two fractions of date-pits fibers were developed by alkaline digestion of whole date-pits powder at 70 °C for 24 h, one from the residue and other one from the supernatant after digestion. Residue and supernatant fibers showed higher hygroscopicity as compared to the date-pits powder (P < 0.05), while there was no significant difference between them (P > 0.05). Similar trends were also observed for water absorption and solubility. Higher absorption indicated that treated fibers could hold more water with higher swelling capacity. In addition, higher FTIR absorption bands of the residue and supernatant fibers at the selected functional groups indicated the molecular damage of the date-pits after digestion. Multivariate analysis of the FTIR spectra bands showed that date-pits powder, residue and supernatant fibers possed different molecular structure. Rigid proton mobility increased in the case of residue and supernatant fibers as compared to the date-pits powder, while mobility of semi-rigid and mobile protons decreased in the cases of residue and supernatant fibers. This indicated that the molecular structural damage occurred by alkaline treatment, and this increased mobility of the semi-rigid and mobile pools of protons and interfering each other, thus reduced the resultant mobility of these pools of protons. It was also evident that extracted supernatant fibers showed the aluminum chelating ability, thus had the ability to reduce aluminum toxicity. Graphical Abstract | Functional Characterization of Alkaline Digested Date-Pits: Residue and Supernatant Fibers | 10.1007/s12649-022-01890-y |
2023-04-01 | This paper investigates the nonlinear low-velocity impact response of geometrically imperfect graphene platelets-reinforced metal foams (GPLRMF) cylindrical shells under axial motion. Based on Love’s thin shell theory and von Karman's geometric nonlinearity, the nonlinear equations of motion for the GPLRMF cylindrical shells are established. Then, combined with the Galerkin method, the fourth-order Runge–Kutta technique is adopted to simulate the time history curves of the GPLRMF cylindrical shells, in which the simply supported boundary condition is considered. Subsequently, the nonlinear impact force between the GPLRMF cylindrical shells and impactor is obtained by using Hertz contact force model and Newton's second law. In the end, numerical results are presented to investigate the effects of various parameters including foam distribution, graphene platelets (GPLs) distribution pattern, GPLs weight fraction, foam coefficient, axially moving velocity of the cylindrical shells, radius and initial velocity of the spherical impactor, pre-stressing force, damping coefficient and initial geometrical imperfection on the nonlinear low-impact response of the GPLRMF cylindrical shells. | Nonlinear low-velocity impact response of graphene platelet-reinforced metal foam cylindrical shells under axial motion with geometrical imperfection | 10.1007/s11071-022-08186-9 |
2023-04-01 | Abstract New results of studying the one-sided surface modification of polymer films and flat-sheet composite membranes based on poly(vinyltrimethylsilane) using low-temperature plasma are presented. Treatment is carried out by direct current discharge at a cathode and anode, air is used as a working medium, the exposure time is from 10 to 60 s, and the working pressure in a chamber is 15–20 Pa. The structure of the surface layers is analyzed by XPS, AFM, and SEM, and the contact properties of the surface are studied. For cathode-treated PVTMS films the effective permeability coefficients for O 2 , N 2 , СН 4 , СО 2 , Не, and Н 2 , as well as the effective gas diffusion coefficients, are measured experimentally and the effective gas solubility coefficients are calculated. The permeability coefficients of the studied gases for cathode- and anode-modified composite membranes with a selective PVTMS layer are determined. It is shown that the choice of electrode significantly affects not only the chemical structure of surface and near-surface PVTMS layers but also the gas-transport parameters of the modified samples. It is found that, in the case of cathode-modified homogeneous films, the values of permeability, diffusion, and solubility coefficients of gases are higher while the values of selectivity are lower compared with the anode-modified films. At the same time, the treatment of PVTMS films at the cathode for 30 s makes it possible to increase O 2 /N 2 selectivity by more than two times relative to the initial values. The results of modification of the composite membranes differ from those attained for the homogeneous films, and, what is more, for the composite membrane treated at the cathode the O 2 /N 2 selectivity is higher by a factor of 2.5 than the initial value. The potential of using surface modification of polymer films and membranes by low-temperature plasma to improve their gas-separation properties is demonstrated. | Effect of Low-Temperature Plasma on the Structure of Surface Layers and Gas-Separation Properties of Poly(Vinyltrimethylsilane) Membranes | 10.1134/S2517751623020063 |
2023-04-01 | Abstract This paper discusses the use of multicomponent composites as advanced nanostructured coatings. Their composition and synthesis conditions allow a simultaneous nucleation of islands of different mutually insoluble phases, which limit the island growth. Components for the coatings are chosen so that, firstly, to form nitrides, carbides, oxides, and more complex compounds with a high enthalpy of formation. Secondly, to form insoluble copper and nickel in order to reduce differences in the elastic moduli of the substrate and coating, eliminate stress concentrators, and increase the fracture toughness of the surface layers. The phase-structural state and the elastic stress distribution in the coatings are investigated to assess the torsional lattice curvature and local internal stresses as one of the most important factors in increasing the coating microhardness to HV = 40 GPa. Two types of substructures were distinguished in the nanocoatings depending on the composition: a nanocomposite one with less than 20-nm crystals in the amorphous matrix, and a two-level substructure with grains of hundreds of nanometers fragmented into 10- to 20-nm crystals. High elastic and elastoplastic bending-torsion was observed in coatings of various types. Using Ti-Al-Si-Ni-Cr-Cu-C-O-N coatings as an example, we confirm the effectiveness of the proposed multicomponent coating design principles that provide high hardness, fracture toughness, and thermal stability. | Physical Design Principles of Thermally Stable Multicomponent Nanocomposite Coatings | 10.1134/S1029959923020030 |
2023-04-01 | Benefitting from low cost and simple synthesis, simple structured non-fused ring acceptors (NFRAs) and polymer donors are crucial for the application of organic solar cells (OSCs). Herein, two isomerized NFRAs, namely 4T-FClFCl and 4T-2F2Cl, are designed with end-group engineering, which modulates the electrostatic potential distributions and crystallinity of acceptors, and accordingly, the A/A and D/A intermolecular interactions. The OSC based on 4T-2F2Cl with strong D/A interactions shows a record-high efficiency of 16.31% in blending with a low-cost polymer donor PTQ10, which shapes obviously improved bulkheterojunction (BHJ) networks blade-coated by non-halogenated solvent o -xylene, and thus significantly diminishes non-radiative recombination loss. A higher industrial figure of merit (i-FOM) of 0.46 for PTQ10:4T-2F2Cl in comparison with PTQ10:4T-FClFCl (i-FOM=0.29) is demonstrated owing to its superior device efficiency and operational stability. Note that the i-FOM of PTQ10:4T-2F2Cl is the highest value for OSCs reported so far. This work deepens the synergistic effect of the A/A and D/A interactions on achieving desired bulk heterojunction morphology and demonstrates a printable photovoltaic system for low-cost, high-efficiency, stable, and eco-friendly OSCs. | Low-cost organic photovoltaic materials with great application potentials enabled by developing isomerized non-fused ring acceptors | 10.1007/s11426-022-1502-3 |
2023-04-01 | In recent years, previously reported studies revealed a high efficiency of pollutant degradation by coupling photocatalysis and electrochemical processes (PECs) using titanium dioxide (TiO 2 ) photoelectrode rather than using photocatalysis or electrocatalysis alone. However, some of the TiO 2 photoelectrodes that have been reported were not cost-effective. This is due to the use of expensive chemicals and certain expensive equipment in the fabrication process, other than involving complicated preparation steps. Therefore, this study is aimed at investigating the PEC performance and stability of low-cost TiO 2 -polyvinyl chloride (TiO 2 -PVC) composite photoelectrode for Reactive Orange 16 (RO16) degradation. The materials characterisation using the ATR-FTIR, XRD and UV-Vis DRS proved that TiO 2 and TiO 2 -PVC were successfully synthesised. The micrograph obtained for the surface characterisation using the FESEM showed that the smooth surface of freshly prepared photoelectrodes turned slightly rough with tiny pits formation after five continuous PEC processes. Nevertheless, the photoelectrode retained its original shape in good condition for further PEC processes. By PEC process, the fabricated photoelectrode showed 99.4% and 51.1% of colour and total organic carbon (TOC) removal, respectively, at optimised PEC parameters (1.0 mol L −1 NaCl concentration, 10 V applied voltage, 120 min degradation time and initial pH 2). Moreover, the fabricated photoelectrode demonstrated sufficient reusability potential (~ 96.3%) after five cycles of PEC processes. In summary, a low-cost and stable composite photoelectrode with high efficiency in RO16 degradation was successfully fabricated and could be potentially applied for other emerging pollutants degradation via the PEC degradation technique. | Potential of low-cost TiO2-PVC composite in photoelectrocatalytic degradation of reactive orange 16 under visible light | 10.1007/s11356-023-25623-3 |
2023-04-01 | The potential of an agricultural waste ( Calophyllum inophyllum seed husk) as a low-cost adsorbent for the removal of dyes from an aqueous solution was studied. Biosorption of Alizarin Yellow (AY), an anionic dye, and Malachite Green (MG), a cationic dye, onto modified C. inophyllum seed husk showed that certain modifications improved the adsorption property of this adsorbent. Modification of the seed husk with a combination of carbonization and microwave irradiation (HCM) worked best for the removal of AY, while a base-treated carbonized form (HCB) of the husk produced the best result for the removal of MG. Batch adsorption studies were conducted, and various parameters such as pH, initial concentration of the adsorbates, adsorbent dose, time, and temperature were optimized to evaluate the adsorption behavior of the biomass. Optimum dye removal was obtained at pH 3 for AY and pH 5 for MG after 100 min of the adsorbent and adsorbate interaction. Kinetic data obtained fitted better into the pseudo-second-order model, thus suggesting a chemisorption mechanism. Equilibrium studies showed that the removal of the dyes is best represented with the Freundlich isotherm model, suggesting a heterogeneous surface of the modified C. inophyllum seed husk and also indicating that surface adsorption is not the rate-determining step. Adsorption capacities of 27.90 mg/g and 31.25 mg/g were obtained for AY and MG, respectively. Thermodynamic parameters with ∆ H o values of 4139.29 J/mol for AY and 10,089.04 J/mol for MG and ∆ S o values of 3.61 and 28.38 J/mol/K for AY and MG, respectively, show that the adsorption processes are endothermic in nature, entropy-driven, and nonspontaneous. The results showed that the low-cost biomass possesses the potential for the effective removal of both cationic and anionic dyes from wastewater. | Equilibrium, kinetic, and thermodynamic studies of the adsorption of anionic and cationic dyes from aqueous solution using agricultural waste biochar | 10.1007/s13738-022-02721-6 |
2023-04-01 | Cache memory is a key component for most microprocessors in embedded system. The increasing processing load has resulted in an upsurge in the demand for low power, high performance SRAM bit cells. Consequently, in this paper a 7T bit cell is designed for feature size 32 nm and 300 mV supply voltage. The improvement in the performance of the proposed cell is validated against the results obtained for pre-existing 6T, 7T, 8T, 9T, and 10T cells. The read and hold noise margin for the cell is obtained to be 96 and 68 mV respectively, whereas the static margin for the write operation is 170 mV. To perform a successful write operation, a pulse-width of 30 ns is utilized. The power analysis reveals that the proposed cell has minimal read/write power consumption. The leakage power for the cell is 8.4 pW and 1.2 pW for Q = ‘0’ and ‘1’ respectively. Tolerance analysis justifies that the cell maintains its functionality and yields credible outputs under process-voltage-temperature variations for static performance metrics. The layout for the proposed 7T cell occupies 0.584 µm 2 area. This is 5.55% smaller than a single ended 6T. The area for other 7T counterparts, 8T, 9T, and 10T cells is larger than the proposed cell. | A low power single bit-line configuration dependent 7T SRAM bit cell with process-variation-tolerant enhanced read performance | 10.1007/s10470-023-02147-x |
2023-04-01 | In this experiment, a gas–liquid two-phase discharge water treatment inverse device was designed independently to treat the actual workshop intermediate dye wastewater from a chemical plant. Firstly, the effects of initial concentration of wastewater, initial pH, circulation flow rate of solution, content of Fe 2+ , content of H 2 O 2 , and addition of tert-butanol on the organic removal rate and decolorization rate of dye wastewater treatment were investigated. The results showed that Fe 2+ and tert-butanol would react with the active particles (H 2 O 2 , ·OH) and inhibit the degradation of the dye wastewater, resulting in the decrease of both organic matter degradation rate and decolorization rate. The experimentally degraded dye wastewater mainly contained benzoic acid and its derivatives in addition to dye molecules, thus the degradation mechanism of benzoic acid was mainly analyzed. Then, the actual dye wastewater treated by low-temperature plasma was combined with the traditional biological treatment technology. The biochemical properties of the wastewater treated by low-temperature plasma technology were greatly improved, and the B/C was increased from the initial 0.17 to 0.33. The effluent after the combined biological method could meet the effluent discharge standard, and the final CODcr reached 198 mg/L, BOD 5 reached 65 mg/L, and pH and chromaticity reached 6.39 and 50, respectively. | Experimental study on the treatment of dye wastewater by plasma coupled biotechnology | 10.1007/s11356-023-26590-5 |
2023-04-01 | Abscisic acid (ABA) is an important phytohormone that regulates seed germination, dormancy, and plant responses to stresses such as salt, drought, and cold. Melatonin regulates ABA biosynthesis and catabolism during seed germination under various types of stress; however, the transcriptional regulation of ABA signaling genes by melatonin during cucumber seed germination under low temperature (LT, 15 °C) stress is poorly understood. Here we report that melatonin promoted seed germination under LT stress by decreasing ABA content and increasing the gibberellic acid (GA)/ABA ratio (gibberellic acid, GA). We also examined the expression levels of the ABA receptors PYR/PYL/RCAR (PYL), as well as the negative regulator protein phosphatase type 2C (PP2C) and positive regulator subfamily 2 of SNF1-related kinase (SnRK2) by real-time PCR. The expression of most tested genes increased during seed germination, showing an opposite trend to ABA level. The transcript levels of CsPYL1 , CsPYL2 , CsPYL3 , CsPYL8 , and CsPYL10 in 10 μM melatonin-pretreated seeds were significantly increased after 6 h of imbibition as a result of feedback regulation caused by the lack of ABA, and CsPP2C3 , CsPP2C5 , and CsSnRK2.1 exhibited higher expression levels than CK (control) treatment. The expression of most tested genes changed markedly in the initial water uptake phase (12 h after imbibition), suggesting that this period is critical for the regulation of ABA signaling during seed germination. We speculate that melatonin reduces ABA content, preventing CsPYL ( CsPYL1/2/3/8/10 ) binding to CsPP2C and thereby enhancing the activity of CsPP2C ( CsPP2C3/5 ) and blocking CsSnRK2.1 activation. Phosphorylation of the downstream factors ABA-responsive element-binding factor (ABF)/ABA-responsive element-binding protein (AREB) by CsSnRK2.1 is thus abolished, leading to seed germination under LT stress. | Melatonin Promotes Seed Germination via Regulation of ABA Signaling Under Low Temperature Stress in Cucumber | 10.1007/s00344-022-10698-y |
2023-04-01 | An extremely low friction state was observed on the gold surface induced by applying a specific negative potential in cationic surfactant solution. The friction force showed a remarkable reduction from 8.3 to 3.5 × 10 −2 nN (reduced by 99.6%) with increasing the period of negative applied potential, and the final friction coefficient could reduce down to 3 × 10 −4 . The extremely low friction state was robust, and it also exhibited an excellent load bearing capacity, which cannot be damaged by a high load. Moreover, the extremely low friction state achieved under negative applied potential could keep stable even after the removal of potential, but failed in a short time, once a specific positive potential was applied. It was demonstrated that there was a stable electro-adsorption of surfactant molecules on the gold surface induced by applying a negative potential, leading to the formation of a bilayer structure on the gold surface. The hydration layers of the bilayer on the gold surface and micelles on the silica probe provided a shear plane with an extremely low shear strength, leading to the extremely low friction state on the gold surface. This study provides a method to achieve extremely low friction state by applied potential. | Extremely low friction on gold surface with surfactant molecules induced by surface potential | 10.1007/s40544-022-0608-7 |
2023-04-01 | After more than a year of unrest, a small effusive eruption commenced in Fagradalsfjall, Iceland, on 19 March 2021. The eruption lasted six months. The first six weeks were characterized by multiple fissure openings, and the remainder was dominated by effusive activity from a single crater. During the eruption, lava and low-level gases propagated over the complex terrain: a hyaloclastite massif with mountain peaks up to about 350 m asl with valleys in between. The area is uninhabited, but easily accessible at about 30 km distance from Reykjavík. While the eruption was ongoing, more than 356,000 tourists visited the eruptive site. To maintain low risk access to the area, it was critical to monitor the eruption (including opening of new fissures) in real-time, forecast the transport of gas and lava flow emplacement, and assess the evolving hazards. In addition to data accessibility and interpretation, managing this volcanic crisis was possible thanks to strong collaboration between the scientific institutions and civil protection agencies. The eruption presented an opportunity to tune, test and validate a variety of numerical models for hazard assessment as well as to refine and improve the delivery of information to the general public, communities living near the eruption site and decision makers. The monitoring team worked long hours during both the pre- and syn-eruptive phases for identifying low risk access areas to the eruption site and to provide a regular flow of information. This paper reviews the eruption and its associated hazards. It also provides an overview of the monitoring setup, the adopted numerical tools and communication materials disseminated to the general public regarding current exclusion zones, hazards and possible future eruptive scenarios. | The eruption in Fagradalsfjall (2021, Iceland): how the operational monitoring and the volcanic hazard assessment contributed to its safe access | 10.1007/s11069-022-05798-7 |
2023-04-01 | In this study, coffee husk was used as input raw material to produce biochar by slow pyrolysis process at 350 °C for 60 min. Coffee husk biochar with the size from 0.2 to 1.0 mm was introduced into sequencing batch reactor (SBR) system to evaluate the granulation process of activated sludge together with chemical oxygen demand (COD) and ammonium removal efficiency. Coffee husk biochar in the experiment acted as a bio carrier to promote the formation of the granular sludge in the system. Synthetic wastewater used in this study had COD/total nitrogen (C/N) ratio was adjusted gradually reduced from the optimal ratio of 20/1 to low C/N ratio of 3/1. In about 3 weeks of continuous operation, the granular sludge was initially formed with small size (less than 1 mm) and then gradually increased in bigger size and was stable in the size of 2–3 mm for long operation time (over 90 days). The treatment efficiency of COD and ammonium in the system was maintained (COD treatment efficiency was 90% and ammonium was nearly 70%). The results indicated that granular sludge formation process also possessed sludge volume index (SVI) reduction dramatically, sludge settled quickly and reduced the amount of sludge discharged. Therefore, using biochar could be a potential effective method to enhance granulation of activated sludge in SBR system for treating low C/N ratio wastewater. Graphical abstract | Performances of coffee husk biochar addition in a lab-scale SBR system for treating low carbon/nitrogen ratio wastewater | 10.1007/s13399-021-01788-0 |
2023-04-01 | The nanopore structure and evolution of shale reservoirs have been a research hotspot because they have important impacts on the storage of shale gas. In this paper, thermal simulation experiments were carried out on a Lower Cambrian shale with high maturity taken from the western Hubei area, southern China, to obtain a suite of sub-samples with different maturities. The results show that within the EqRo (equivalent vitrinite reflectance) range of 2.96–4.36%, the specific surface areas of OM (organic matter) and IM (inorganic matter) nanopores in the shale increased at first and then decreased, reaching maximum at 3.64% EqRo. As EqRo > 3.64%, the pore volume of OM decreased significantly, while the pore volume of IM showed an increase. The specific surface area and volume of OM pore increased first and then decreased with increase in CH 4 yield, indicating that the thermal evolution and methanogenesis of OM were not always conducive to the development of pore structure, and the late graphitization (EqRo > 3.64%) may be the main mechanism for the destruction of the OM pore structure. The continuous increase of IM pore volume was attributed mainly to the decomposition of minerals such as illite and calcite, which formed pore spaces. The effective maturity range of the Lower Cambrian shale gas in the western Hubei area can reach to EqRo of 3.64%, which is an important guide to the exploration and development of shale gas in this area. | Nanopore Structure Evolution of Lower Cambrian Shale in the Western Hubei Area, Southern China, and its Geological Implications based on Thermal Simulation Experimental Results | 10.1007/s11053-022-10149-1 |
2023-04-01 | Soil salinity negatively affects plant growth, productivity, and metabolism. Rice is known to have more sensitive phenotypes than other cereal crops such as wheat ( Triticum aestivum ), sorghum ( Sorghum bicolor ), and barley ( Hordeum vulgare ). We characterized the molecular function of rice ( Oryza sativa ) C3HC4 as a really interesting new gene (RING). O. sativa RING finger protein HC-2 ( OsSIRHC-2 ) was highly expressed in 100 mM NaCl and was targeted to the cytosol. An in vitro ubiquitin assay demonstrated that OsSIRHC-2 possessed E3-ubiquitin ligase activity. Under salinity conditions, OsSIRHC-2 -overexpressing plants exhibited higher chlorophyll, proline, and soluble sugar contents and lower H 2 O 2 accumulation than wild-type plants, supporting transgenic plants with enhanced salinity tolerance phenotypes. OsSIRHC-2 -overexpressing plants exhibited low Na + accumulation and Na + /K + ratios in their roots. Low expression of some Na + transporter genes, especially OsHKT1;4 was consistent with the low Na + accumulation in transgenic plants. These results suggest that OsSIRHC-2 may play a positive regulatory role in high salinity through the low absorption of Na + . Understanding the salt tolerance mechanisms of OsSIRHC-2 may provide a crucial strategy for plant adaptation to salinity. | Overexpression of Rice C3HC4-Type RING Finger Protein Gene, OsSIRHC-2, Improves Salinity Tolerance Through Low Na+ Accumulation | 10.1007/s12374-023-09382-9 |
2023-04-01 | Peri-conceptional environment can induce permanent changes in embryo phenotype which alter development and associate with later disease susceptibility. Thus, mouse maternal low protein diet (LPD) fed exclusively during preimplantation is sufficient to lead to cardiovascular, metabolic and neurological dysfunction in adult offspring. Embryonic stem cell (ESC) lines were generated from LPD and control NPD C57BL/6 blastocysts and characterised by transcriptomics, metabolomics, bioinformatics and molecular/cellular studies to assess early potential mechanisms in dietary environmental programming. Previously, we showed these lines retain cellular and epigenetic characteristics of LPD and NPD embryos after several passages. Here, three main changes were identified in LPD ESC lines. First, their derivation capacity was reduced but pluripotency marker expression was similar to controls. Second, LPD lines had impaired Mitogen-activated protein kinase (MAPK) pathway with altered gene expression of several regulators (e.g., Maff , Rassf1 , JunD ), reduced ERK1/2 signalling capacity and poorer cell survival characteristics which may contribute to reduced derivation. Third, LPD lines had impaired glucose metabolism comprising reduced upstream enzyme expression (e.g., Gpi, Mpi ) and accumulation of metabolites (e.g., glucose-6-P, fructose-6-P) above the phosphofructokinase (PFK) gateway with PFK enzyme activity reduced. ESC lines may therefore permit investigation of peri-conceptional programming mechanisms with reduced need for animal experimentation. Graphical Abstract | Maternal Undernutrition Induces Cell Signalling and Metabolic Dysfunction in Undifferentiated Mouse Embryonic Stem Cells | 10.1007/s12015-022-10490-1 |
2023-04-01 | Abstract The mineralogical, structural and crystal-chemical features of seven samples of globular phyllosilicates of the glauconite–illite series (GPS) from the Lower Cambrian sequences of Northern Estonia and Western Lithuania, from the Middle Cambrian sequences of Western Latvia, and also from the Lower Ordovician sequences of Northern Estonia and Western Latvia are considered for the first time. Based on Al index ( K Al = VI Al/[ VI Fe 3+ + VI Al]) varying from 0.27 to 0.59, the globular phyllosilicates are attributed to the glauconite–illite series, most of which are represented by glauconites (the Al index is K Al = 0.27–0.46) and one sample, by Al-glauconite ( K Al = 0.59). The K 2 O content in minerals is from 7.12 to 7.90%. The content of expandable layers (4–13%), their types (smectite, vermiculite), and the character of their alternation (R = 0, R = 2) were determined for the first time in the studied samples by simulation of experimental X-ray diffraction patterns from oriented specimens. Simulation of X-ray diffraction patterns obtained from unoriented specimens made it possible to determine the degree of three-dimensional order and mean values of the unit-cell parameter b (9.056–9.094 Å), as well as the distribution of their individual micaceous varieties. Based on these data, the microheterogeneity of the Cambrian and Ordovician GPSs was established and compared with the heterogeneity in the previously studied Riphean GPS (Drits et al., 2013). The obtained Rb-Sr и K‑Ar ages for the studied Middle Cambrian and Lower Ordovician samples, as well as the earlier published dates for the Lower Cambrian samples, are “rejuvenated” relative to age limits accepted for the Cambrian and Lower Ordovician (Gradstein et al., 2020). The relationship of the Cambrian and Lower Ordovician “rejuvenated” isotopic dates and the discovered GPS heterogeneity, as well as possible reasons for its occurrence, are discussed. | Globular Phyllosilicates of the Glauconite–Illite Series in the Cambrian and Ordovician Rocks of the Eastern Baltica (Northern Estonia, Western Lithuania, and Western Latvia) | 10.1134/S002449022270002X |
2023-04-01 | We investigate the influence of cross thermal buoyancy to initiate the vortex shedding process around two side-by-side circular cylinders kept in a free stream flow. The critical buoyancy parameter is assessed for the Reynolds number in the range 10–40. In the stated range, a steady separated flow evolves under the pure forced convective condition. However, with the introduction of thermal buoyancy, instability grows and at a specific value of the buoyancy parameter, the flow turns into unsteady periodic with the formation of vortex shedding. The above phenomena have been examined numerically by a two dimensional simulation based on a finite volume method for a fixed gap spacing between the cylinders and considering air as the working medium. It is observed that the strength of the buoyancy could be a decisive factor in demarcating various flow regimes. The critical strengths of buoyancy where the flow transforms into unsteady periodic from the steady pattern are estimated for the Reynolds number range. It shows a decreasing pattern with increasing Reynolds number. The flow transition is visualized through the vorticity, isotherm contours, lift signals and phase diagrams. Furthermore, a regime diagram is constructed to clearly depict various zones of hydrodynamic behavior. | The role of cross thermal buoyancy on flow transition around side-by-side cylinders at low Reynolds numbers | 10.1007/s10973-022-11620-0 |
2023-04-01 | Airborne particulate matter (PM) pollution, as a leading environmental health risk, causes millions of premature deaths globally every year. Lower respiratory infection (LRI) is a sensitive response to short-term exposure to outdoor PM pollution. The airborne transmission of etiological agents of LRI, as an important pathway for infection and morbidity, bridges the public health issues of air quality and pathogen infectivity, virulence, resistance, and others. Enormous efforts are underway to identify common pathogens and substances that are etiological agents for LRI and to understand the underlying toxicological and clinical basis of health effects by identifying mechanistic pathways. Seasonal variations and geographical disparities in the survival and infectivity of LRI pathogens are unsolved mysteries. Weather conditions in geographical areas may have a key effect, but also potentially connect LRI with short-term increases in ambient air PM pollution. Statistical associations show that short-term elevations in fine and coarse PM lead to increases in respiratory infections, but the causative agents could be chemical or microbiological and be present individually or in mixtures, and the interactions between chemical and microbiological agents remain undefined. Further investigations on high-resolution monitoring of airborne pathogens in relation to PM pollution for an integrated exposure–response assessment and mechanistic study are warranted. Improving our understanding of the spatiotemporal features of pathogenic bioaerosols and air pollutants and translating scientific evidence into effective policies is vital to reducing the health risks and devastating death toll from PM pollution. Graphical abstract | On the triad of air PM pollution, pathogenic bioaerosols, and lower respiratory infection | 10.1007/s10653-021-01025-7 |
2023-04-01 | The dairy industry is a very productive sector worldwide and known for producing great volumes of wastewater that is rich in organic matter and nutrients. Apart from fat, the organic matter in such effluents is easily degradable, demanding an external carbon source for conventional denitrification. In this manner, new configurations of reactors promoting a suitable environment for more sustainable nitrogen removal are beyond required—they are paramount. Therefore, the performance of a structured-bed hybrid baffled reactor (SBHBR) with anaerobic and oxic/anoxic chambers was designed and assessed for treating different dairy wastewaters. A combination of baffled and biofilm-structured systems under intermittent aeration was the solution proposed to obtain a new method for nitrogen removal under low COD/TN ratios. The COD/TN ratios tested were 2.1 ± 0.6, 0.84 ± 0.5, and 0.35 ± 0.1 in the inlet of the O/A chambers for operational stages I, II, and III, respectively. The SBHBR provided COD removal efficiencies above 90% in all experimental stages. During stage III, the process had nitrification and denitrification efficiencies of 85.9 ± 17% and 85.2 ± 9%, respectively, resulting in a TN removal efficiency of 74.6 ± 14.7%. Stoichiometric calculations were used to corroborate the activity of bacteria that could perform the anammox pathways as their main mechanisms. | Evaluating the potential of a new reactor configuration to enhance simultaneous organic matter and nitrogen removal in dairy wastewater treatment | 10.1007/s11356-023-26341-6 |
2023-04-01 | Portable applications and battery-operated devices require highly reliable, stable, and low-power nanometer-sized embedded cache static random access memory (SRAM) cells. The conventional 6-transistor (6 T) SRAM cell and its variants suffer from malfunctioning during the read/write operations, and instability, and are vulnerable to the multi-bit soft-error rate at scaled technology node and low supply voltage ( V DD ). In this regard, this paper proposes an 12 T SRAM cell with reliable functioning and reduced multi-bit soft-errors appropriate for low-power portable applications. This cell performs single-end bitline decoupled read operation and write data-dependent feedback-cutting-aware differential write operation to improve the read static noise margin (RSNM) and write static noise margin (WSNM), respectively. The presence of stack transistors in the cell core and read path, and also high virtual ground ( V GND ) minimize the leakage power dissipation. The proposed cell is compared with other state-of-the-art SRAM cells at V DD = 0.7 V and under harsh process, voltage, and temperature (PVT) variations. It offers at least 1.18X higher RSNM, 1.27X higher WSNM, and 2.02X lower leakage power dissipation. It also shows the second-best read power and incurs a penalty in write power. This cell shows at least 1.17X, 1.32X, and 1.04X smaller spread in read delay, RSNM, and WSNM, respectively, when subjected to PVT variations. In addition, the proposed cell eliminates the write half-select disturbance by employing a separate gate to drive the access transistors and thus column-interleaving structure and error correction coding can be applied to reduce multiple-bit upset and increase soft-error immunity. The soft-error in the proposed cell is reduced by at least 1.37X in critical charge. Generally, the proposed cell offers the best overall performance among all the compared cells by showing the highest proposed figure of merit. | A robust multi-bit soft-error immune SRAM cell for low-power applications | 10.1007/s10470-023-02144-0 |
2023-04-01 | In this study, we assess the performance of the Regional Climate Model version 4 (RegCM4) in simulating the climatology of the cyclones near the west coast of South America. The synoptic evolution and seasonality of these systems are thoroughly investigated. The analyses are based on four simulations from the CORDEX-CORE Southern America (SA) domain, at 0.25° of horizontal resolution: one driven by ERA-Interim and three driven by different GCMs. The reference dataset is represented by ERA5. Cyclones were detected by an objective scheme in the period 1995–2005 and classified in three different classes: (i) Coastal Lows (CLs) and cyclones affecting the coast (CAC) (ii) crossing and (iii) not crossing the Andes. In general, RegCM4 is able to reproduce the climatology of cyclones affecting the western coast of SA. In particular: (i) CLs are shown to be more frequent in austral summer although their frequency is underestimated by the simulations in this season; (ii) CAC not crossing the Andes represent 76% of all CAC and are more frequent in winter, with simulation underestimating their frequency by ~ 22% due to the differences in the simulated upper-level jets, which tend to get weaker (by ~ 5–10 m s − 1 ) northwards of 30°S; (iii) the frequency of CAC crossing the Andes tends to be overestimated mainly in winter, which is associated with the combination of the stronger upper-level jets and weaker SLP in the simulations, especially southwards of 40°S. | Assessment of the RegCM4-CORDEX-CORE performance in simulating cyclones affecting the western coast of South America | 10.1007/s00382-022-06419-6 |
2023-04-01 | Five low-rank coal samples with different water saturations were tested using nuclear magnetic resonance. The stress sensitivity, compressibility and inhomogeneity variation of coal internal space, including micropores, meso–macropores and microfractures, were analyzed, and the effects of water saturation on the above characteristics were compared. The spatial size is the main factor that affected the stress sensitivity and compressibility of the internal space and water migration. The total stress sensitivity and compressibility were contributed by all kinds of coal internal spaces, and the contribution degree was correlated positively with the percentage of pore volume. As effective stress rises, the coal internal space exhibited a series of variations: the stress sensitivity increased while the compressibility decreased; the distributional complexity showed a slight change of decreasing first and then increasing; and the inhomogeneity stabilized gradually. Affected by the pore–fracture distribution, the water migrated into a stable state driven by stress. The water saturation controlled the migration priority of water in different-sized pores and affected the amount of the degree of stress that acted on the inhomogeneity of coal internal space; the increasing water saturation enhanced the stress on the inhomogeneity of coal internal space; the compressive disturbing effect of water in meso–macropores and total coal internal space were weakened as water saturation decreases. In addition, the minimum values of stress and compression disturbing effect on coal internal water occurred when the water saturation was 60%, and the water distribution was more stable than other saturations. | Experimental Study of Water Distribution Affected by Stress Sensitivity and Pore–Fracture Compressibility of Low-Rank Coals with Different Levels of Water Saturation | 10.1007/s11053-023-10158-8 |
2023-04-01 | Effects of low-melting Pr–Cu alloy addition on the microstructure and magnetic properties of the hot-deformation Nd–Fe–B magnets were investigated. A small amount of Pr–Cu addition enhances the coercivity of the hot-deformation Nd–Fe–B magnets obviously. The coercivity of the hot-deformation Nd–Fe–B magnets with 4.0 wt% Pr 85 Cu 15 addition increases to 1271 kA·m −1 , 75.69% higher than that of Pr–Cu-free magnet (723 kA·m −1 ), and then decreases with 5 wt% Pr 85 Cu 15 addition. It is observed that there a uniform RE-rich phase is formed wrapping the Nd 2 Fe 14 B main phase in the sample with 4.0% Pr 85 Cu 15 addition by scanning electron microscopy (SEM), which promotes the coercivity. The angular dependence of coercivity for the hot-deformation Nd–Fe–B magnets indicates that the coercivity mechanism is nucleation combined with domain wall pinning. The domain wall pinning is weakened, while the nucleation is enhanced after Pr–Cu addition. The remanence, intrinsic coercivity, and maximum magnetic energy product of the original Nd–Fe–B magnet are 1.45 T, 723 kA·m −1 , and 419.8 kJ·m −3 , respectively, and those of the sample with 4.0% Pr 85 Cu 15 alloy addition are 1.30 T, 1271 kA·m −1 , and 330.0 kJ·m −3 , respectively. | Coercivity enhancement of hot-deformed Nd–Fe–B magnets with Pr–Cu alloy addition | 10.1007/s12598-017-0993-7 |
2023-04-01 | Abstract The results of the study on the vertical distribution of abiotic characteristics and chlorophyll (Chl a ) in the Gorky, Cheboksary, Kuibyshev, Saratov, and Volgograd reservoirs in the summer of 2021 are presented. The content of Chl a varied from 5.5–8.5 to >100 μg/L in the Middle Volga to 22 and 47 μg/L in the Lower Volga, and was typical for the summer maximum of phytoplankton in the Volga reservoirs. In the absence of density stratification for most stations, a uniform Chl a distribution in the water column was revealed with variation coefficients of no more than 20%. | Characteristics of the Vertical Distribution of Chlorophyll in Reservoirs of the Middle and Lower Volga | 10.1134/S1067413623020091 |
2023-04-01 | Abstract Salinity is one of the leading environmental factors influencing the distribution of zebra mussel Dreissena polymorpha in natural conditions. The data on the tolerance range of salinity that were obtained by predecessors under field conditions and during experimental studies differ significantly. This makes it difficult to assess the possible range of distribution of zebra mussel under natural conditions and predict the possibility of its introduction to new water bodies. Using the indices of osmotic and ionic homeostasis as a research method, we have tried to estimate the tolerance range and optimal, critically low, and critically high salinity zones for D. polymorpha . The results can be used to predict the range of distribution of zebra mussel in nature and assess the physiological state of the mollusks in natural and laboratory conditions. | Assessment of the Limits of the Tolerance range and Optimal, Critically Low, and Critically High Salinity Zones according to the Indices of Osmotic and Ionic Homeostasis of Dreissena polymorpha | 10.1134/S106741362302008X |
2023-04-01 | Abstract In the present work ultrasonic waves with low frequency (24 kHz) without any additives were introduced for extreme reduction the Reactive Blue 256 dye in aqueous solution. The significant parameters of pH, irradiation time, and initial concentration were considered for evaluating the dye removal’s efficiency at constant temperature of 25°C. The ultrasonic waves led to cracking the hydrocarbon linkages through ultrasonic energy and cavitation phenomenon. The main, interaction and second order effects were investigated through a quadratic model and analysis of variance based on Box-Behnken design (BBD). In response surface methodology (RSM), numerical optimization procedure of the dye removal determined a maximum value of 102.065% which had an error of 7.4% compared to the experimental one of 95%. Finally, artificial neural network (ANN) models was developed. The modeling results showed clearly that the RSM had a more powerful performance than the ANN. | Modeling and Optimization Study on Decolorization of Reactive Blue 256 Exposed to Low Frequency Ultrasonic Waves: RSM and ANN Approaches | 10.3103/S1063455X23020078 |
2023-04-01 | Promoting financial sustainability is the focus of current state policies while addressing the concerns of environmental pollution. The alarming impacts of climate change on economies motivate us to revisit an intensive empirical study to explore the dynamic relationships of low-carbon energy, current account balance, and reserves with carbon dioxide (CO 2 ) emissions in the most polluted countries across the globe for the years 1981–2020. We applied the dynamic autoregressive distributive lag (D-ARDL) simulation model to investigate the short and long-run connection. The empirical outcomes of the study uncover that in the short run, a 1% increase in renewable energy reduces CO 2 -based emissions by 0.417%, 0.169%, and 0.619% in China, the USA, and India, respectively. We further explored that China’s and the USA’s economic growth causes environmental deterioration. In contrast, a 1% increase in current account balances improves the environmental quality of China and India by 0.3% and 0.6%, respectively. This research concludes that model variables significantly impact the environment. Therefore, it is necessary to draw policy implications to increase the consumption of low-carbon energy to sustain economic growth by limiting the adverse impacts of economic activities. | Moving towards sustainability: how do low-carbon energy, current account balance, and reserves induce environmental deterioration in the Big 3? | 10.1007/s11356-023-26339-0 |
2023-04-01 | Parking structures taller than 8 m in height are difficult to design because both fire resistance and seismic resistance must be considered, whereas structures shorter than this threshold are simpler to design and are subject to fewer construction restrictions. Therefore, to optimize the design of these low parking structures, we propose a novel wide, long-span, steel–concrete composite beam that can be applied to reduce their story height. We investigated flexural and shear-bonding performance of the developed composite beams based on experiments, as well as theoretical and analytical research. Seven flexural beams were loaded at two supports prior to monotonic bending tests, and four shear bonding beams were tested using compressive loading schemes. As a result of the flexural tests indicated that the flexural strength of the wide composite-steel beams increased by approximately 20% as steel thickness increased by 3 mm (from 6 to 9 mm). Shear-bonding tests showed that all specimens without shear connectors exhibited insufficient shear-bonding strength to resist the mechanical bond mechanism; therefore, they should be reinforced with two or more flat bars. As a result, the novel composite beam system can be applied to reduce construction costs and resources by decreasing floor height in systems with long-span beams. | Experimental Study on Structural Performance of New Steel–Concrete Composite Beam for Both Long-Span and Low-Height Parking Structures | 10.1007/s13296-022-00702-2 |
2023-04-01 | Abstract Streptomyces albulus is a well-established cell factory for ε-poly-L-lysine (ε-PL) production. It has been reported that ε-PL biosynthesis is strictly regulated by pH and that ε-PL can accumulate at approximately pH 4.0, which is outside of the general pH range for natural product production by Streptomyces species. However, how S. albulus responds to low pH is not clear. In this study, we attempted to explore the response of S. albulus to low-pH stress at the physiological and global gene transcription levels. At the physiological level, S. albulus maintained intracellular pH homeostasis at ~pH 7.5, increased the unsaturated fatty acid ratio, extended the fatty acid chain length, enhanced ATP accumulation, increased H + -ATPase activity, and accumulated the basic amino acids L-lysine and L-arginine. At the global gene transcription level, carbohydrate metabolism, oxidative phosphorylation, macromolecule protection and repair, and the acid tolerance system were found to be involved in combating low-pH stress. Finally, we preliminarily evaluated the effect of the acid tolerance system and cell membrane fatty acid synthesis on low-pH tolerance via gene manipulation. This work provides new insight into the adaptation mechanism of Streptomyces to low-pH stress and a new opportunity for constructing robust S. albulus strains for ε-PL production. Key points • S. albulus consistently remained pH i at ~7.4 regardless of the environmental pH. • S. albulus combats low-pH stress by modulating lipid composition of cell membrane. • Overexpression of cfa in S. albulus could improve low-pH tolerance and ɛ-PL titer. Graphical abstract | Understanding the Streptomyces albulus response to low-pH stress at the interface of physiology and transcriptomics | 10.1007/s00253-023-12449-9 |
2023-04-01 | Purpose The prognosis of recurrent glioblastoma (rGBM) is poor, and there is currently no effective treatment strategy. Sonodynamic therapy (SDT) is a new method for cancer treatment that uses a combination of low-frequency ultrasound and sonosensitisers to produce antitumor effects, which have shown good therapeutic effects in preclinical studies. Therefore, we initiated an open, prospective pilot study to evaluate the safety, tolerability, and efficacy of SDT for the treatment of rGBM. Methods Nine patients with rGBM were enrolled who had received multiple treatments, but the nidus continued to progress without additional standard treatments. After MRI localisation, porphyrin drugs were injected, and intermittent low-frequency ultrasound therapy was performed for five days. Results None of the nine patients in this clinical trial showed any clinical, neurological, haematological, or skin-targeted adverse effects associated with SDT. After the completion of the trial, one patient maintained stable disease, and eight patients experienced disease progression. Among the eight with progressive disease, the median progression-free survival time was 84 days. Four patients died, and the median overall survival duration after recurrence was 202.5 days. Conclusion The number of patients in this study was small; therefore, a long-term survival benefit was not demonstrated. However, this study suggests that SDT has potential as a treatment for rGBM and warrants further exploration. Trial information: Chinese Clinical Trial Registry ( http://www.chictr.org.cn/ ) : ChiCTR2200065992. November 2, 2022, retrospectively registered. | A phase I clinical trial of sonodynamic therapy combined with temozolomide in the treatment of recurrent glioblastoma | 10.1007/s11060-023-04292-9 |
2023-04-01 | Objectives This study examined specificity in the effects of three perinatal mindfulness-based prevention programs that differed in their timing (prenatal, postpartum) and target (maternal well-being, parenting). Effects on maternal mental health (depression, anxiety, resilience), mindfulness, and observed parenting, as well as observed, physiological, and mother-report indicators of infant self-regulation, were examined. Methods The programs were evaluated in a racially and ethnically diverse sample of first-time mothers ( n = 188) living in low-income contexts using intention-to-treat analysis. Mothers were assigned to a prenatal well-being, postpartum well-being, parenting, or book control group. Multi-method assessments that included questionnaire, observational, and physiological measures were conducted at four time points: during pregnancy (T1) and when infants were 2–4 months (T2), 4–6 months (T3), and 10–12 months. Results Compared to the postpartum intervention and control groups, the 6-week prenatal well-being intervention was related to decreases in depressive symptoms during pregnancy but not postpartum, higher maternal baseline respiratory sinus arrhythmia (RSA), fewer intrusive control behaviors, and lower infant cortisol levels in the early postpartum period. Compared to all other groups, the postpartum parenting intervention was related to decreases in maternal anxiety and increases in responsive parenting. Some differential effects across programs might be due to differences in attendance rates in the prenatal (62%) vs. postpartum (35%) groups. Conclusions The findings suggest that brief mindfulness-based well-being and parenting preventive interventions can promote maternal and infant mental health in families living in low-income, high-stress settings, particularly if accessibility can be enhanced. Preregistration This study is not preregistered. | Preliminary Evaluation of the Effectiveness of Perinatal Mindfulness-Based Well-Being and Parenting Programs for Low-Income New Mothers | 10.1007/s12671-023-02096-6 |
2023-04-01 | To develop low-carbon agriculture, it is necessary to deeply analyze the spatial evolution and regional differences of China’s agricultural carbon emission efficiency (ACEE). Clarifying how the carbon emission efficiency differs between and within regions and how it evolves can help achieve a win–win situation for both economy and ecology. This study uses the inter-provincial agricultural industry panel data from 2000 to 2019 and selects the three-stage super-efficiency slack-based measure data envelope analysis (SBM-DEA) model to measure ACEE. Additionally, this study uses the Dagum Gini coefficient and the Kernel density model to analyze the sources of regional differences in ACEE and the internal dynamic evolution, respectively. The empirical results reveal the following: (i) China’s ACEE is in a state of “inefficient”. Only the ecological protection area is “efficiently optimized”. Moreover, the phenomenon of “ACEE agglomeration” appears spatially in Southern and Northern China for a certain periods of time. (ii) The overall Gini coefficient of China’s ACEE has shown a gradual decline, which indicates that the overall ACEE is converging, while the intra-group gap and transvariation intensity between regions have primarily contributed to the regional gap in China’s ACEE. (iii) The absolute difference of the internal ACEE between regions shows an expanding trend, and the uneven development of the ACEE between regions is obvious. Based on the results, this paper could put forward a basis for effectively formulating regionally differentiated emission reduction policies and better realizes the development of sustainable agriculture. | Regional differences and dynamic evolution of China’s agricultural carbon emission efficiency | 10.1007/s13762-022-04196-7 |
2023-04-01 | Purpose While clinical practice suggests that knowing the cerebral autoregulation (CA) status of traumatic brain injury (TBI) patients is crucial in assessing the best treatment, evidence in pediatric TBI (pTBI) is limited. The pressure reactivity index (PRx) is a surrogate method for the continuous estimation of CA in adults; however, calculations require continuous, high-resolution monitoring data. We evaluate an ultra-low-frequency pressure reactivity index (UL-PRx), based on data sampled at ∼5-min periods, and test its association with 6-month mortality and unfavorable outcome in a cohort of pTBI patients. Methods Data derived from pTBI patients (0–18 years) requiring intracranial pressure (ICP) monitoring were retrospectively collected and processed in MATLAB using an in-house algorithm. Results Data on 47 pTBI patients were included. UL-PRx mean values, ICP, cerebral perfusion pressure (CPP), and derived indices showed significant association with 6-month mortality and unfavorable outcome. A value of UL-PRx of 0.30 was identified as the threshold to better discriminate both surviving vs deceased patients (AUC: 0.90), and favorable vs unfavorable outcomes (AUC: 0.70) at 6 months. At multivariate analysis, mean UL-PRx and % time with ICP > 20 mmHg, remained significantly associated with 6-month mortality and unfavorable outcome, even when adjusted for International Mission for Prognosis and Analysis of Clinical Trials in TBI (IMPACT)-Core variables. In six patients undergoing secondary decompressive craniectomy, no significant changes in UL-PRx were found after surgery. Conclusions UL-PRx is associated with a 6-month outcome even if adjusted for IMPACT-Core. Its application in pediatric intensive care unit could be useful to evaluate CA and offer possible prognostic and therapeutic implications in pTBI patients. ClinicalTrials.gov NCT05043545, September 14, 2021, retrospectively registered. | Evaluation and application of ultra-low-frequency pressure reactivity index in pediatric traumatic brain injury patients | 10.1007/s00701-023-05538-1 |
2023-04-01 | Diabetic wound treatment has posed a significant challenge in clinical practice. As a kind of cell-derived nanoparticles, extracellular vesicles produced by adipose-derived stem cells (ADSC-EVs) have been reported to be potential agents for diabetic wound treatment. However, ADSC-EV yield is insufficient to meet the demands of clinical therapy. In this study, a novel method involving the use of low-intensity ultrasound stimulation on ADSCs is developed to promote EV secretion for clinical use. A proper low-intensity ultrasound stimulation parameter which significantly increases ADSC-EV quantity has been found. In addition, EVs secreted by ADSCs following low-intensity ultrasound stimulation (US-EVs) are enriched in wound healing-related miRNAs. Moreover, US-EVs promote the biological functions of fibroblasts, keratinocytes, and endothelial cells in vitro, and promote diabetic wound healing in db/db mice in vivo through re-epithelialization, collagen production, cell proliferation, keratinocyte differentiation and migration, and angiogenesis. This study proposes low-intensity ultrasound stimulation as a new method for promoting significant EV secretion by ADSCs and for improving the diabetic wound-healing potential of EVs, which will meet the clinical needs for these nanoparticles. Graphical Abstract The production of extracellular vesicles of adipose-derived stem cells is obviously promoted by a low-intensity ultrasound stimulation method, and the biological effects of promoting diabetic wound healing were markedly increased in vitro and in vivo | Production and Biological Effects of Extracellular Vesicles from Adipose-Derived Stem Cells Were Markedly Increased by Low-Intensity Ultrasound Stimulation for Promoting Diabetic Wound Healing | 10.1007/s12015-022-10487-w |
2023-04-01 | Genus Wolfia Horkel ex Schleiden ( Araceae , former Lemnaceae ) includes 11 species that are the smallest of known flowering plants. The genus is widespread in the world. In Europe, the only native species is Wolffia arrhiza . In Poland, it is considered to be relatively rare and until the end of the 20th century it was known from small number of populations dispersed throughout the country Poland. Our research focused on Lower Silesia population of Wolffia arrhiza . The study included the verification of historical sites of this species known from the literature and an inventory of the contemporary occurrence. It also aimed to explain the pattern of W. arrhiza occurrence in selected habitats and determine the ecological conditions and phytocoenoses of the reservoirs it inhabits. The research of the species showed extinction of historical sites and the current presence in 12 water reservoirs of different origin, size, depth and management method. The share of W. arrhiza in phytocoenosis patches in the individual reservoirs is very diverse and ranges from 15 to 80%. Presented data supplement the information on the occurrence of W. arrhiza in western Poland as well as provide new information on its biology and ecology. | Distribution and ecology of Wolffia arrhiza (L.) Horkel ex Wimm. In the lowland part of Lower Silesia (Poland) | 10.1007/s11756-022-01276-4 |
2023-04-01 | In 2011, aiming to achieve sustainable development in the transportation sector, the Chinese government started a pilot policy of low-carbon transportation system (LCTS). Based on the panel data for 280 prefecture-level cities in China from 2006 to 2017, we first measure carbon efficiency by using the SBM-DEA model, and identify the direct and spatial spillover effects of LCTS on carbon efficiency and carbon intensity by adopting a spatial difference-in-differences approach (SDID). The results indicate that LCTS construction not only enhances local carbon performance but also has a significant spatial spillover effect in neighboring cities. The results are still valid after a series of robustness tests. The mechanism analysis reveals that LCTS can elevate carbon performance by improving energy efficiency, green innovation, and developing public transit. The direct and indirect effects of LCTS on carbon performance show more pronounced effects in megalopolis and eastern region. This paper provides reliable empirical evidence for the effect of LCTS on carbon performance, which is conducive to deepening the understanding of carbon emissions and has a high reference value for the rational formulation of carbon reduction policies. | The effect of low-carbon transportation pilot policy on carbon performance: evidence from China | 10.1007/s11356-023-25940-7 |
2023-04-01 | Realizing a high-performance and energy-efficient circuit system is one of the critical tasks for circuit designers. Conventional researchers always concentrated on the tradeoffs between the energy and the performance in circuit and system design based on accurate computing. However, as video/image processing and machine learning algorithms are widespread, the technique of approximate computing in these applications has become a hot topic. The errors caused by approximate computing could be tolerated by these applications with specific processing or algorithms, and large improvements in performance or power savings could be achieved with some acceptable loss in final output quality. This paper presents a survey of approximate computing from arithmetic units design to high-level applications, in which we try to give researchers a comprehensive and insightful understanding of approximate computing. We believe that approximate computing will play an important role in the circuit and system design in the future, especially with the rapid development of artificial intelligence algorithms and their related applications. | A Survey of Approximate Computing: From Arithmetic Units Design to High-Level Applications | 10.1007/s11390-023-2537-y |
2023-04-01 | Transportation sector has become a major contributor to the escalation of carbon emissions and subsequent climate change. In this study, a bibliometric analysis was conducted using CiteSpace on published papers (1991–2022). Then a theoretical framework was proposed through traditional content analysis from three aspects: measurement, mechanism analysis, and low-carbon pathways analysis. The clustering results show that the research topics have involved mainly factor analysis, evaluation, system analysis, control measurement and pollutants. A further summary of the content of the relevant literature shows that there are five main accounting methods for measuring transportation carbon emissions (TCEs), which can be applied to different scenarios. Studies involving the spatio-temporal distribution of TCEs is limited and mainly focus on macroperspectives. The mechanism of TCEs involves three main aspects: system assessment, efficiency measurement, and driver analysis, which serve to identify the internal patterns of TCEs. Finally, the outlook regarding TCEs is presented. | A systematic review of transportation carbon emissions based on CiteSpace | 10.1007/s11356-023-26533-0 |
2023-04-01 | Continuous lighting for 14 days (functional pinealectomy model) leads to a decrease in the relative number of CD3 low and CD3 hi T lymphocytes and the CD3 low /CD3 hi ratio in the thymus of C57BL/6 mice. Intragastric administration of melatonin in physiological doses (1 mg/kg body weight, 14 days) against the background of functional pinealectomy restores the percentage of CD3 low and CD3 hi thymocytes and CD3 low /CD3 hi ratio to the control values. Hence, prolonged continuous illumination inhibits the differentiation and maturation of young thymocytes into mature forms, while melatonin treatment helps to compensate the effects of functional pinealectomy triggering cell proliferation in the thymus from the earliest stages of proliferation and differentiation of T cells. Thus, melatonin has immunotropic properties and can be used for correction of the consequences of functional pinealectomy. | Effect of Melatonin on the Content of CD3low and CD3hi T Cells in the Thymus of Mice with Functional Pinealectomy | 10.1007/s10517-023-05786-2 |
2023-03-31 | Low-density viscosity measurements on eight gaseous and vapor mixtures between 297 K and 638 K, originally performed using oscillating-disk viscometers, were re-evaluated after improved re-calibration. The relative combined expanded ( $$k=2$$ k = 2 ) uncertainty of the re-evaluated data are 0.2 % near room temperature and increases to 0.3 % at higher temperatures. The re-evaluated data were converted into quasi-isothermal viscosity data. Those for carbon dioxide–ethane, propane–isobutane, and methanol–triethylamine could be used to determine the zero-density and initial density viscosities, $$\eta _\text{mix}^{(0)}$$ η mix ( 0 ) and $$\eta _\text{mix}^{(1)}$$ η mix ( 1 ) . The $$\eta _\text{mix}^{(0)}$$ η mix ( 0 ) data for carbon dioxide–ethane agree almost perfectly with viscosity values theoretically computed for the nonspherical potential of the intermolecular interaction. Three procedures were applied to determine the interaction viscosity, $$\eta _{ij}^{(0)}$$ η ij ( 0 ) , and the product of molar density and diffusion, $$(\rho D_{ij})^{(0)}$$ ( ρ D ij ) ( 0 ) , both in the limit of zero density. In a first procedure only applicable for the three mentioned mixtures, $$\eta _{ij}^{(0)}$$ η ij ( 0 ) values were derived from the $$\eta _\text{mix}^{(0)}$$ η mix ( 0 ) data additionally requiring $$A_{ij}^*$$ A ij ∗ values (ratio between effective cross sections of viscosity and diffusion). This procedure should provide the best results when it is possible to use $$A_{ij}^*$$ A ij ∗ values computed for the nonspherical potential. This was only feasible for carbon dioxide–ethane, for which the experimentally based $$\eta _{ij}^{(0)}$$ η ij ( 0 ) and $$(\rho D_{ij})^{(0)}$$ ( ρ D ij ) ( 0 ) data perfectly agree with theoretically calculated values. For the seven other mixtures, the resulting data represent only preliminary ones. The second and third procedures were applied to the six vapor mixtures methanol with triethylamine, benzene, and cyclohexane and benzene with toluene, p -xylene, and phenol. The resulting data showed a density dependence and were extrapolated to zero density. | Viscosity for Eight Gaseous and Vapor Mixtures: Revisited from Experiment Between 297 K and 638 K. Final and Preliminary Values for the Interaction Viscosity and for the Product of Molar Density and Diffusion Coefficient in the Limit of Zero Density | 10.1007/s10765-023-03174-6 |
2023-03-30 | Background HER2-low could be found in some patients with triple-negative breast cancer (TNBC). However, its potential impacts on clinical features and tumor biological characteristics in TNBC remain unclear. Methods We enrolled 251 consecutive TNBC patients retrospectively, including 157 HER2-low (HER2 low ) and 94 HER2-negtive (HER2 neg ) patients to investigate the clinical and prognostic features. Then, we performed single-cell RNA sequencing (scRNA-seq) with another seven TNBC samples (HER2 neg vs. HER2 low , 4 vs. 3) prospectively to further explore the differences of tumor biological properties between the two TNBC phenotypes. The underlying molecular distinctions were also explored and then verified in the additional TNBC samples. Results Compared with HER2 neg TNBC, HER2 low TNBC patients exhibited malignant clinical features with larger tumor size ( P = 0.04), more lymph nodes involvement ( P = 0.02), higher histological grade of lesions ( P < 0.001), higher Ki67 status ( P < 0.01), and a worse prognosis ( P < 0.001; HR [CI 95%] = 3.44 [2.10–5.62]). Cox proportional hazards analysis showed that neoadjuvant systemic therapy, lymph nodes involvement and Ki67 levels were prognostic factors in HER2 low TNBC but not in HER2 neg TNBC patients. ScRNA-seq revealed that HER2 low TNBC which showed more metabolically active and aggressive hallmarks, while HER2 neg TNBC exhibited signatures more involved in immune activities with higher expressions of immunoglobulin-related genes ( IGHG1 , IGHG4 , IGKC , IGLC2 ); this was further confirmed by immunofluorescence in clinical TNBC samples. Furthermore, HER2 low and HER2 neg TNBC exhibited distinct tumor evolutionary characteristics. Moreover, HER2 neg TNBC revealed a potentially more active immune microenvironment than HER2 low TNBC, as evidenced by positively active regulation of macrophage polarization, abundant CD8 + effector T cells, enriched diversity of T-cell receptors and higher levels of immunotherapy-targeted markers, which contributed to achieve immunotherapeutic response. Conclusions This study suggests that HER2 low TNBC patients harbor more malignant clinical behavior and aggressive tumor biological properties than the HER2 neg phenotype. The heterogeneity of HER2 may be a non-negligible factor in the clinical management of TNBC patients. Our data provide new insights into the development of a more refined classification and tailored therapeutic strategies for TNBC patients. | Clinical and biological heterogeneities in triple-negative breast cancer reveals a non-negligible role of HER2-low | 10.1186/s13058-023-01639-y |
2023-03-30 | N7-methylguanosine (m7G) modification signature has recently emerged as a crucial regulator of tumor progression and treatment in cancer. However, there is limited information available on the genomic profile of lower-grade gliomas (LGGs) related to m7G methylation modification genes’ function in tumorigenesis and progression. In this study, we employed bioinformatics methods to characterize m7G modifications in individuals with LGG from The Chinese Glioma Genome Atlas (CGGA) and The Cancer Genome Atlas (TCGA). We used gene set enrichment analysis (GSEA), single sample GSEA (ssGSEA), CIBERSORT algorithm, ESTIMATE algorithm, and TIDE to evaluate the association between m7G modification patterns, tumor microenvironment (TME) cell infiltration properties, and immune infiltration markers. The m7G scoring scheme using principal component analysis (PCA) was employed to investigate the m7G modification patterns quantitatively. We examined the m7G modification hub genes' expression levels in normal samples, refractory epilepsy samples, and LGG samples using immunohistochemistry, western-blotting, and qRT-PCR. Our findings revealed that individuals with LGG could be categorized into two groups based on m7G scores (high and low) according to the properties of m7G. Moreover, we observed that high m7G score was associated with significant clinical benefit and prolonged survival duration in the anti-PD-1 cohort, while low m7G score was associated with improved prognostic outcomes and increased likelihood of complete or partial response in the anti-PD-L1 cohort. Different m7G subtypes also showed varying Tumor Mutational Burden (TMB) and immune profiles and might have distinct responses to immunotherapy. Furthermore, we identified five potential genetic markers that were highly correlated with the m7G score signature index. These findings provide insight into the features and classification associated with m7G methylation modifications and may aid in improving the clinical outcome of LGG. | N7-methylguanosin regulators-mediated methylation modification patterns and characterization of the immune microenvironment in lower-grade glioma | 10.1186/s40001-023-01108-4 |
2023-03-29 | This paper presents a low-power sub-bandgap voltage reference. Here, the proportional to absolute temperature (PTAT) voltage obtained from ∆V EB is applied to a subthreshold diode-connected PMOS transistor to yield a current with a positive thermal coefficient (TC). The current is then converted back to a PTAT voltage term using another subthreshold PMOS transistor at the output path. Moreover, utilizing the bipolar transistor achieves a lower process variation VR. A trimming circuit is also applied to improve the TC against the process variation further. Low-power VR is achieved by operating all the MOSFETs under the subthreshold region. The simulation results using the standard 1.8 V, 0.18 µm CMOS process shows a nominal output voltage of 0.75 V, operating from 0.9 V to 1.8 V supply voltage while consuming 41.4 nA at room temperature. The TC is about 21.6 ppm/ o C and (σ VREF /μ VREF ) = 1.0 % over a temperature range of 0 °C to 120 °C. In addition, the proposed VR circuit is simulated without a trimming circuit resulting in a reasonable μ TC = 29.1 ppm/ o C and (σ VREF /μ VREF ) = 1.3%. | Resistorless sub-bandgap CMOS voltage reference based on lateral BJT | 10.1007/s12046-023-02102-6 |
2023-03-29 | Water-induced soil erodibility is the most severe kind of land degradation, with substantial environmental and social consequences. Few studies have been conducted on land cover change and soil erodibility in Ethiopia. During the data search, 83 articles were looked at, with studies published from 2007 to 2022. Only 2% of the abstracts that were considered for assessment were eventually accepted. The review was conducted using the preferred reporting items for systematic reviews and a meta-analysis approach. According to this study, when compared to the values predicted in the river basin’s master plan, Baro Akobo’s estimated surface water potential has been reduced by about 3.6 Bm 3 . As a result, changes in land cover affected a variety of fundamental processes in watersheds, at several spatial and temporal scales. As a result, of the reviewed, in lower Baro, built-up/settlement, agricultural land, water body, bare/outcrop, and commercial farm all rose by roughly + 195, + 48, + 35, + 35, and + 1%, respectively. Shrubland, rangeland, forest land, and wetland, on the other hand, all decreased by − 1, − 0.5, − 5, and − 10%, respectively. The K-factors are 0.31, 0.23, 0.14, and 0.07 for chromatic vertisols, humic cambisols, eutric cambisols, and eutric nitosols, respectively. From the results of the review studies, the RUSLE looks to be a good alternative for assessing soil erodibility in lower Baro, and soil water conservation measures are crucial for minimizing soil erodibility. | Land cover change and its implications to hydrological variables and soil erodibility in Lower Baro watershed, Ethiopia: a systematic review | 10.1007/s40899-023-00843-0 |
2023-03-29 | The retention of contaminants within low-conductivity regions such as clay lenses and aquitards can greatly affect groundwater remediation processes. The aim of this study was to experimentally investigate the effects of the geometry of low-conductivity zones, conductivity contrast, and flow regime on solute flushing. We conducted a series of flushing tests in cylindrical models containing a cylindrical low-conductivity zone (i.e., low- K zone) embedded in a highly conductive medium (i.e., high- K zone). Seven models comprising four high-conductivity-contrast (SL, SS, LL, and LS), one medium-contrast (LLM), one low-contrast (LLL), and one homogeneous (H) models were considered. Experiments were conducted at two flow rates ( Q = 0.6 and 26 cm 3 /min) for each heterogeneous model (SL, SS, LL, LS, LLM, and LLL) to compare the flushing processes in different flow regimes. First, we verified the validity of our experiments by comparing the results of the H model from an analytical solution with our experiment. The results of the high-contrast models showed that for a diffusion-dominated regime ( Q = 0.6 cm 3 /min), the pore volume injected (PVI) required to flush out solute mass was much smaller than that in an advection-dominated regime ( Q = 26 cm 3 /min). To evaluate the pore volumes required to flush out solutes for the four high-contrast models, we introduced a parameter P 0.01 , which is defined as the PVI needed for the relative concentration to become 0.01 at the middle of the low- K zone. P 0.01 decreases with increasing the specific surface area of the low- K zone for diffusion-dominated regimes, while it increases with increasing the length of the low- K zone for advection-dominated regimes. We also determined the importance of the effect of K contrast on solute retention by comparing the results of three different models of K contrast (LL, LLM, and LLL). | Laboratory Flushing Tests of Dissolved Contaminants in Heterogeneous Porous Media with Low-Conductivity Zones | 10.1007/s11270-023-06236-5 |
2023-03-27 | This paper presents a case study for the testing of locally available resources selected to form a clay barrier. This is a promising technique for protecting historic masonry from ground moisture intrusion. There are several historical precedents for the use of calcareous, clayey soils to form moisture resilient barriers in architecture. More recently, specialised bentonite mixtures have arrived on the market. Assessment protocols for suitable barrier material will help establish general codes and the potential for this technique to make use of locally available resources, either in their raw state or in mixtures. In this project, a variety of different geo-materials are collected from around Pompeii to test their suitability for use in a barrier installation on a tomb in the archaeological site. The methodology consists of laboratory tests used in the assessment of barrier material for landfill engineering, and rapid tests used in earth construction. A mixture of a calcareous clay and a sand produced barrier material with suitable properties. The methodology can form the basis of assessments elsewhere, to further develop the potential of using locally available geo-resources for conservation and construction projects. | Assessing the suitability of local earth resources for use in clay barriers to protect historic masonry in Pompeii | 10.1007/s12665-023-10842-1 |
2023-03-27 | Background Fucosyltransferase 2(FUT2) and its induced α-1,2 fucosylation is associated with cancer metastasis. However, the role of FUT2 in colorectal cancer (CRC) metastasis remains unclear. Methods The expression levels and clinical analyses of FUT2 were assessed in CRC samples. Migration and invasion assays, EMT detection, nude mice peritoneal dissemination models and intestinal specific FUT2 knockout mice (FUT2 △IEC mice) were used to investigate the effect of FUT2 on metastasis in colorectal cancer. Quantitative proteomics study of glycosylated protein, UEA enrichment, Co-immunoprecipitation identified the mediator of the invasive-inhibiting effects of FUT2. Results FUT2 is downregulated in CRC tissues and is positively correlated with the survival of CRC patients. FUT2 is an inhibitor of colorectal cancer metastasis which, when overexpressed, suppresses invasion and tumor dissemination in vitro and in vivo. FUT2 knock-out mice (FUT2 △IEC mice) develop AMO and DSS-induced tumors and promote EMT in colorectal cancers. FUT2-induced α-1,2 fucosylation impacts the ability of low-density lipoprotein receptor-related protein 1(LRP1) to suppress colorectal cancer invasion. Conclusions Our study demonstrated that FUT2 induces α-1,2 fucosylation and inhibits EMT and metastasis of colorectal cancer through LRP1 fucosylation, suggesting that FUT2 may serve as a therapeutic target for colorectal cancer. Video Abstract | FUT2 inhibits the EMT and metastasis of colorectal cancer by increasing LRP1 fucosylation | 10.1186/s12964-023-01060-0 |
2023-03-23 | The use of diatoms as indicators of water quality has been studied worldwide; however, the use of diatoms as indicators of thermic anomalies has received less attention. The objective of this study is not only to provide a record on algal communities, but also to investigate the relationship between the diversity in diatom species and the physicochemical conditions of water. Evaluating its temporal variability in a caldera with low permeability and cold acid hydrothermal anomalies. Diatom assemblages were identified at 11 sites. Species composition was compared between seasons (dry and wet) in different environments, as streams, ponds and pools within the caldera. The physicochemical and environmental differences are very specific, which allowed the diatom identification from geothermal and anthropogenic sources without finding mixtures. The results show that the main diatom flora of the Acoculco caldera consists of 15 dominant species. Sulphite-rich acidic hydrothermal waters are characterized by the presence of Eunotia exigua , Eunotia bilunaris , and Pinnularia brauniana . In non-hydrothermal streams, Planothidium, Achnanthidium , and Humidophila species are the most common taxa. Other diatoms from acidic environments were Frustulia saxonica, Surirella , and Stenopterobia . The assemblages are clearly different from those of alkaline environments. Epithemia , Planothidium , and Ulnaria are present in the streams and are not associated with thermalism. Ordination of diatom assemblages showed that pH, conductivity, and nutrient concentrations, some of which are influenced by anthropogenic activities, were the main factors influencing the distribution of diatom composition. | Diatom assemblages from different environments of the Acoculco Caldera associated to hydrothermal and anthropogenic activity | 10.1007/s10661-023-11125-9 |
2023-03-23 | We compare the capacity of entanglement with the entanglement entropy by considering various aspects of these quantities for free bosonic and fermionic models in one spatial dimension, both in the continuum and on the lattice. Substantial differences are observed in the subleading terms of these entanglement quantifiers when the subsystem is made by two disjoint intervals, in the massive scalar field and in the fermionic chain. We define c -functions based on the capacity of entanglement similar to the one based on the entanglement entropy, showing through a numerical analysis that they display a monotonic behaviour under the renormalisation group flow generated by the mass. The capacity of entanglement and its related quantities are employed to explore the symmetry resolution. The temporal evolutions of the capacity of entanglement and of the corresponding contour function after a global quench are also discussed. | Probing RG flows, symmetry resolution and quench dynamics through the capacity of entanglement | 10.1007/JHEP03(2023)175 |
2023-03-22 | Abstract Low temperature affects plant growth and biomass accumulation in the Qinghai-Tibet Plateau. Bacillus is an important plant growth-promoting rhizobacteria that can promote plant growth directly or indirectly. In this study, bacteria suspensions (cell concentration 1 × 10 7 cfu/mL) of Bacillus amyloliquefaciens strain GL18 were interacted with Avena sativa seedlings by the root irrigation method under 4°C low-temperature conditions. The biomass accumulation, as well as the physiological and biochemical activities of A. sativa , was detected over 14 days. The results showed that the plant height, root length, fresh and dry weight of A. sativa treated at 4°C with B. amyloliquefaciens by root irrigation increased by 39.28, 32.50, 114.89, and 87.17%, respectively, compared to untreated control. The levels of plant hormones such as abscisic acid, salicylic acid and jasmonic acid were significantly increased, and the activities of superoxide dismutase, peroxidase and catalase increased rapidly and then decreased slowly. The accumulation of hydrogen peroxide and malondialdehyde decreased, and the contents of proline and betaine increased significantly. The genome of GL18 strain was sequenced and its related functional genes were analyzed. The results showed that genome of GL18 strain contained gene clusters encoding proteins related to the synthesis of lipopeptide compounds such as surfactin, iturin, and fengycin, encoding genes involved in 3-indole acetic acid synthesis as well as genes related to the synthesis of plant growth-promoting substances such as siderophore and polyamines. This study provided experimental data and a theoretical basis for the manner in which Bacillus promotes the growth of A . sativa under low-temperature stress. | Physiological Response of Avena sativa to Low-Temperature Stress is Promoted by Bacillus amyloliquefaciens GL18 and Its Functional Genes | 10.1134/S1021443722601586 |
2023-03-22 | The current study aims to valorize the roots of a medicinal plant of the family Rabeacea called Rubia tinctorum L. ( Rubia t.L. ), by phytochemical analyses, and by pointing out the antioxidant and corrosion inhibitory proprieties of the soxhlet extract using different solvent. The content of polyphenols and flavonoids was investigated using colorimetric assays Folin-Ciocalteu, which showed a higher TPC (total phenolic contents) in methanolic extract (129.40 ± 1.78 mg GAE/g), while the flavonoid fraction represents the minor proportion with 63.32 ± 1.41 mg GAE/g. The optimized extract was characterized by UV–vis spectrophotometric analysis and FTIR spectrometric analysis. The antioxidant activities were evaluated using TAC (total antioxidant capacity), DPPH (diphenyl picryl-hydrazyl), free radical scavenging and FRAP method; the obtained results are more significant than those of BHT, ascorbic acid and vitamin E, used as standard. The soxhlet methanolic extract of Rubia tinctorum L. roots was also used as green corrosion inhibitor for low carbon steel (LC-steel) in acid environment (1 M HCl), using the mass loss method and both techniques PDP (potentiodynamic polarization) and EIS (electrochemical impedance spectroscopy) for the electrochemical tests. PDP results reveal that the Rubia t.L. extract functions as a mixed inhibitor. Nyquist plots show that the resistance of charge transfer increases by increasing the inhibitor concentration, whereas the capacity of the double layer decreases. The adsorption of the extract follows the Langmuir isothermal model. The inhibition efficiencies found in the presence of the tested extract through the three electrochemical methods are consistent and are around the value of 95% at the optimum concentration (1 g/l) and a temperature of 298 K. | Phytochemical Characterization, Antioxidant Proprieties and Electrochemical Investigations of Methanolic Extract of Rubia t.L. Roots for LC-Steel Corrosion Protection in 1 M HCl Medium | 10.1007/s40735-023-00749-6 |
2023-03-22 | This paper presents a standalone predictive model for Atomic Oxygen (AO), Coronal Mass Ejections (CMEs) and other space-environment parameters. The prediction is based on the numerical method of Holt–Winter’s triple smooth exponential forecasting of atmospheric constituents. Solar cycle 25 is likely to show about the same activity as cycle 23. The corresponding AO-flux–solar-activity correlation coefficients for altitudes 100, 200, and 300 km are: 0.62, 0.53, and 0.48, respectively, while the correlation coefficients for higher altitudes are lower than 0.48, an advantage that makes them more favorable for LEOs due to the harmful corrosive effects. | A standalone prediction model for atomic oxygen and coronal mass ejections | 10.1007/s10509-023-04170-w |
2023-03-20 | Background Low birth weight (LBW) is associated with infant mortality and postpartum health complications. In previous studies, overall LBW has been found to be significantly associated with several sociodemographic factors, including ethnicity, maternal age, and family income. Few studies have evaluated the association between environmental risk factors and LBW rates. This study investigated the effect of pre-birth water, sanitation, and hygiene (WASH) and housing conditions on self-reported low birth weight. Methods The Ethiopian Demographic and Health Survey, which covered all administrative regions of Ethiopia from January to June 2016, provided data for this study. STATA version 16 was used to analyze 12,125 participants across weighted samples. Multivariable multilevel mixed-effect logistic regression analysis was conducted to determine the effects of each factor on the outcome while accounting for data clustering. The adjusted odds ratios and corresponding 95% confidence intervals were used to determine the statistical significance of the independent variables. Results One thousand five hundred and seventeen newborns, or 12.59% [95% CI (10.2- 15.3)], had low birth weights. When other factors were taken into account, the following factors were significantly associated with low birth weight: not using small-scale water treatment technology before using water [AOR (95% CI) 1.36 (1.08–2.23)], burning solid fuels for energy [AOR (95% CI) 1.99 (1.60–2.21)], living in homes with natural wall coverings [AOR (95% CI) 1.81 (1.47–2.21)], using a shared latrine within a woman's housing complex or compound [AOR (95% CI) 1.63(1.06–2.25)], and living in peripheral, isolated regions [AOR (95% CI) 1.38 (1.06–2.21)]. Conclusion A little more than one out of every ten deliveries in Ethiopia was under normal (recommended) weight. This study shows that poor housing conditions and lack of household WASH infrastructure are independent predictors of poor birth outcomes among Ethiopian women, adding to the limited evidence that environmental factors within the domicile contribute to low birth weight. Interventions to address these issues may help lower the prevalence of LBW. | Using household survey data to explore the effects of the domiciliary environment on weight at birth: a multilevel mixed-effects analysis of the 2016 Ethiopian Demographic Health Survey | 10.1186/s12884-023-05521-9 |
2023-03-20 | Background Nasopharyngeal swabs are taken to determine the causative agent of community acquired pneumonia (CAP), while the reliability of upper respiratory tract sampling as a proxy for lower respiratory tract infections is still unclear. Methods Nasopharyngeal (NP) swabs, bronchoalveolar lavage (BAL) fluid samples and clinical data were collected from 153 hospitalized children between 3 months and 14 years of age with severe CAP, enrolled from March to June 2019. Written informed consent for the storage and use of the samples for further studies was obtained from the parents or caregivers. Putative pathogens were detected using a sensitive, high-throughput GeXP-based multiplex PCR and qPCR. Results The same bacterial species in paired samples were found in 29 (23.4%) and the same viral species in 52 (27.5%) of the patients. moderate concordance was found for Mycoplasma pneumoniae ( ĸ =0.64), followed by Haemophilus influenzae ( ĸ =0.42). The strongest discordance was observed for human adenovirus and also for Pseudomonas aeruginosa , the latter was exclusively detected in BAL samples. In the adenovirus cases strong concordance was associated with high viral loads in the NP swabs. Conclusion The variation in concordance in pathogen detection in the upper and lower respiratory tract of children with severe pneumonia is generally high but varies depending on the species. Novel and impactful insights are the concordance between NP and BAL detection for M. pneumoniae and H. influenzae and the strong correlation between high adenoviral loads in NP swabs and detection in BAL fluid. | Concordance in pathogen identification at the upper and lower respiratory tract of children with severe pneumonia | 10.1186/s12879-023-08127-w |
2023-03-18 | In this work, an electrokinetic-based (EK) reactor was coupled with a biodegradation process to improve the performance of treatment facilities in cold regions. Subsequently, the effects of electric current density (CD) and temperature on chemical oxygen demand (COD) and nutrient removal were investigated in a series of EK bioreactors. Moreover, the potential electro-stimulation of microbial biomass was evaluated. In this experiment, the treatment of synthetic wastewater at different operational temperatures (8, 13, and 20 °C), CD ranging between 1 and 2 mA/cm 2 , and electrical exposure regimes were performed. The results indicated that, at the lower temperature of 8 °C, the EK-based bioreactor with a CD of 1.5 mA/cm 2 at 60 s–ON/180 s–OFF contact mode achieved superior removal efficiencies of impurities over the control bioreactor. The removal of COD, $${\mathrm{NH}}_{4}^{+}-\mathrm{N}$$ NH 4 + - N , and $${\mathrm{PO}}_{4}-\mathrm{P}$$ PO 4 - P was higher than the control bioreactor by 32.6%, 75.9%, and 77% respectively. The outcomes also demonstrated that a CD of 1 mA/cm 2 with an operation mode of 60 s-ON/300 s-OFF was very effective in impurities removal at 20 °C leading to lower energy consumption and treatment costs. Furthermore, it was suggested that the adequate CD application induced microbial biomass responsible for COD and $${\mathrm{NH}}_{4}^{+}$$ NH 4 + bio-utilization. Overall, the alternative EK approach presented in this work could improve the degradation rate by electrically stimulated biomass and optimize the performance of existing treatment plants operated at cold temperatures. Finally, this work establishes a viable approach for either retrofitting existing processes or constructing new wastewater facilities. | Low-temperature treatment of domestic sewage by electrokinetic-based reactor | 10.1007/s13399-023-04034-x |
2023-03-17 | In this paper, an undepleted p-type absorption layer is introduced into the InGaAs/InAlAs separate absorption, grading, charge, and multiplication avalanche photodiode to reduce the dark current and improve the bandwidth. With a multiplication factor 3, the proposed APD has a 28.5 GHz bandwidth and a dark current in the order of picoamperes. In contrast, the bandwidth of an APD with an intrinsic absorption layer is only 23 GHz at the same gain, and the dark current is two orders of magnitude greater. P-type graded doping absorption layers are introduced to form a quasi-field to accelerate electrons transport in the absorption layer. The effects of the concentration profile on the bandwidth were examined, and we found that optimizing the gradient of the concentration profile greatly increased the bandwidth. The effects of the doping concentration and the thickness of the charge layer on the electric field distribution and the operating range of the device were also investigated. The parameters selected for the charge layer allow a wide operating range for the device. | High-speed and low dark current InGaAs/InAlAs avalanche photodiodes with P-type absorption layers | 10.1007/s11082-023-04615-0 |
2023-03-17 | On February 21 and March 21 – 22, 2021, the Extreme Ultraviolet Imager (EUI) onboard Solar Orbiter observed three prominence eruptions. The eruptions were associated with coronal mass ejections (CMEs) observed by Metis, Solar Orbiter’s coronagraph. All three eruptions were also observed by instruments onboard the Solar–TErrestrial RElations Observatory (Ahead; STEREO-A), the Solar Dynamics Observatory (SDO), and the Solar and Heliospheric Observatory (SOHO). Here we present an analysis of these eruptions. We investigate their morphology, direction of propagation, and 3D properties. We demonstrate the success of applying two 3D reconstruction methods to three CMEs and their corresponding prominences observed from three perspectives and different distances from the Sun. This allows us to analyze the evolution of the events, from the erupting prominences low in the corona to the corresponding CMEs high in the corona. We also study the changes in the global magnetic field before and after the eruptions and the magnetic field configuration at the site of the eruptions using magnetic field extrapolation methods. This work highlights the importance of multi-perspective observations in studying the morphology of the erupting prominences, their source regions, and associated CMEs. The upcoming Solar Orbiter observations from higher latitudes will help to constrain this kind of study better. | Three Eruptions Observed by Remote Sensing Instruments Onboard Solar Orbiter | 10.1007/s11207-023-02137-2 |
2023-03-17 | Background Exposure during pregnancy to malaria and sexually-transmitted infections is associated with adverse birth outcomes including low birth weight (LBW). This study aimed at assessing if the adjunction of two doses of azithromycin to sulfadoxine-pyrimethamine for the intermittent preventive treatment of malaria in pregnancy can reduce LBW. Methods A two parallel-groups, open-label randomized controlled trial involving pregnant women (16 to 35 years of age and 12 to 24 weeks of gestation as confirmed by last menstrual period or fundal height) was conducted in rural Burkina Faso. Women were assigned in a 1:1 ratio either to use azithromycin (1 g daily for 2 days) during the second and third trimesters of pregnancy plus monthly sulfadoxine-pyrimethamine (1500/75 mg) (SPAZ) (intervention) or to continue using a monthly sulfadoxine-pyrimethamine (1500/75 mg) (SP) (control). Primary outcome was a LBW (birth weight measured within 24 h after birth < 2500 g). Secondary outcomes including stillbirth, preterm birth or miscarriage are reported together with safety data. Results A total of 992 pregnant women underwent randomization (496 per group) and 898 (90.5%) valid birth weights were available (450 in SPAZ and 448 in SP). LBW incidence was 8.7% (39/450) in SPAZ and 9.4% (42/448) in controls (p-value = 0.79). Compared with controls, pregnant women with SPAZ showed a risk ratio (RR) of 1.16 (95% confidence interval (CI 0.64–2.08]) for preterm births, 0.75 (95% CI 0.17–3.35) for miscarriage and 0.64 (95% CI 0.25–1.64) for stillbirths. No treatment-related serious adverse events (SAEs) have been observed, and there was no significant difference in the number of SAEs (13.5% [67/496] in SPAZ, 16.7% [83/496] in SP, p-value = 0.18) or AEs (17.1% [85/496] in SPAZ, 18.8% [93/496] in SP, p-value = 0.56). Conclusion Adequate prevention regimen with monthly sulfadoxine-pyrimethamine given to all pregnant women has been proved to reduce the risk of LBW in malaria endemic areas. Adding azithromycin to the regimen does not offer further benefits, as far as women receive a malaria prevention regimen early enough during pregnancy. Trial registration Pan African Clinical Trial Registry ( https://pactr.samrc.ac.za/Search.aspx ): PACTR201808177464681. Registered 21 August 2018. | Effects of maternal antenatal treatment with two doses of azithromycin added to monthly sulfadoxine-pyrimethamine for the prevention of low birth weight in Burkina Faso: an open-label randomized controlled trial | 10.1186/s12936-023-04530-5 |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.