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2021-09-01 | It is shown that by irradiating nickel titanium surfaces with a low-energy high-current electron beam of a microsecond duration at the energy densities of E s = 1.5 and 3.7 J/cm 2 using n = 5 pulses it is possible to improve the fatigue characteristics of the material by nearly a factor of 1.5 due to surface cleaning from the particles/inclusions of Ti 2 Ni, TiC(O) and due to the presence in the TiNi surface layer of compressive residual stresses oriented perpendicular to the irradiated surface. | Fatigue Properties of Nickel Titanium and their Improvement Using Low-Energy High-Current Electron Beams | 10.1007/s11182-021-02399-y |
2021-09-01 | Abstract Iron cations Fe $${}^{3+}$$ ( S = 5/2) in inorganic compounds usually effectively interact with each other along three directions, which excludes the presence of correlation effects associated with short-range order. However, some systems with distant fragments containing Fe $${}^{3+}$$ ions due to ligands or other nonmagnetic cations, retain signs of low-dimensional magnetic behavior both above and below the temperature of magnetic ordering. In this review, we have selected examples of iron compounds that can be attributed to the different classes of low-dimensional magnets, including magnetic clusters: dimers in Fe(Te $${}_{1.5}$$ Se $${}_{0.5}$$ )O $${}_{5}$$ Cl, magnetic chains in Bi $${}_{2}$$ Fe(SeO $${}_{3}$$ ) $${}_{2}$$ OCl $${}_{3}$$ , Fe $${}_{2}$$ O(SeO $${}_{3}$$ ) $${}_{2}$$ , magnetic chains with different spins Na $${}_{x}$$ Fe $${}_{7}$$ (PO $${}_{4}$$ ) $${}_{6}$$ ( x = 0, 0.65), MCuFe $${}_{2}$$ (VO $${}_{4}$$ ) $${}_{3}$$ (M $$=$$ Li, Na), magnetic two-dimensional planes with triangular arrangement of magnetic ions MFeO $${}_{2}$$ (M $$=$$ Ag $${}^{+}$$ , Cu $${}^{+}$$ ), MFe(MoO $${}_{4}$$ ) $${}_{2}$$ (M $$=$$ K $${}^{+}$$ , Rb $${}^{+}$$ , Cs $${}^{+}$$ , Tl $${}^{+}$$ ), NaFe $${}_{3}$$ (HPO $${}_{3}$$ ) $${}_{2}$$ ((H,F)PO $${}_{2}$$ OH) $${}_{6}$$ . | Iron-Based Low-Dimensional Magnets | 10.3103/S0027134921050192 |
2021-09-01 | This article characterizes fine-ground NK-Alumina 11 and NK-Alumina 14 developed in PKF “NK” for low-cement refractory castables. The quality indicators of the developed aluminas are not inferior to international analogs. | Production of Fine-Ground NK-Alumina 11 and NK-Alumina 14 for Low-Cement Refractory Castables | 10.1007/s11148-021-00592-7 |
2021-09-01 | We consider specific features of variations of the properties of steels depending on the mode of their thermal treatment. We describe specific features of the influence of impulsive magnetic fields on the metals. We also present the results of testing of important operating characteristics of steels for different conditions of thermal treatment and combined processing with the application of impulsive magnetic fields. The aim of magnetic-pulse treatment is to shorten the idle time of commercial mining machines by increasing the service life of their consumable parts. | Increasing of the Service Life of Consumable Parts of Mining and Metallurgical Machines with the Use of Technologies of Magnetic-Pulse Hardening | 10.1007/s11015-021-01194-x |
2021-09-01 | The effects of 0.01–0.11 wt.% Zr on the inclusions, microstructure, tensile properties, and impact toughness of the China low activation martensitic steel were investigated. Results showed that Zr exhibits good deoxidation and desulfurization abilities. The scanning electron microscope was used to examine the inclusions in the ingots. The main inclusions in the alloys were Zr–Ta–O, Zr–O, and Zr–O–S. However, some blocky Zr-rich inclusions appeared in Zr-2 and Zr-3 alloys. Typical martensitic structures were observed in the alloys, and average prior austenite grain sizes of 21.1, 15.7, and 14.8 µm were obtained for Zr-1, Zr-2, and Zr-3 steels, respectively. However, increasing Zr content of the steels deteriorated their mechanical property, owing to the blocky inclusions. The alloy with 0.01% Zr resulted in excellent mechanical properties due to the fine inclusions and the precipitation of Zr 3 V 3 C carbides. Values of 576 and 682 MPa were obtained for the yield strength and ultimate tensile strength of Zr-1 alloy, respectively. Furthermore, the ductile–brittle transition temperature of the alloy decreased to − 85 °C. | Effect of zirconium on inclusions and mechanical properties of China low activation martensitic steel | 10.1007/s42243-021-00572-8 |
2021-09-01 | The low-temperature wet oxidation behavior of semi-dry desulfurization ash from iron ore sintering flue gas in ammonium citrate solution was investigated for efficiently utilizing the low-quality desulfurization ash. The effects of the ammonium citrate concentration, oxidation temperature, solid/liquid ratio, and oxidation time on the wet oxidation behavior of desulfurization ash were studied. Simultaneously, the oxidation mechanism of desulfurization ash was revealed by means of X-ray diffraction, Zeta electric resistance, and X-ray photoelectron spectroscopy (XPS) analysis. Under the optimal conditions with ammonium citrate, the oxidation ratio of CaSO 3 was up to the maximum value (98.49%), while that of CaSO 3 was only 8.92% without ammonium citrate. Zeta electric resistance and XPS results indicate that the dissolution process of CaSO 3 could be significantly promoted by complexation derived from the ammonium citrate hydrolysis. As a result, the oxidation process of CaSO 3 was transformed from particle oxidation to SO 3 2− ion oxidation, realizing the rapid transformation of desulfurization ash from CaSO 3 to CaSO 4 at low temperature. It provides a reference for the application of semi-dry desulfurization ash and contributes to sustainable management for semi-dry desulfurization ash. | Low-temperature oxidation behavior and mechanism of semi-dry desulfurization ash from iron ore sintering flue gas | 10.1007/s42243-021-00582-6 |
2021-09-01 | Abstract It has been established that low temperature decomposition of martensite in quenched medium carbon steel takes place in two steps. At the first step, the decomposition intensity is higher than at the next step. The use of neutron diffraction made it possible to reveal two stages of transformation at the first step of martensite decomposition. It is demonstrated that the first stage is related mainly to carbon segregation on dislocations and the second stage is related to escape of carbon from oversaturated solid solution with formation of disperse particles of metastable carbides. The degree of tetragonality of the martensite lattice changes during aging and low tempering to a certain limit irrespective of cooling rate during quenching and tempering temperature, which is related to establishment of relative equilibrium between oversaturated solid solution and disperse particles of metastable iron carbide. It has been established that the determining process leading to changes in microhardness upon low temperature decomposition of martensite is escape of carbon from oversaturated solid solution. | Neutron Diffraction Study of Kinetics of Low Temperature Decomposition of Martensite in Medium Carbon Steel | 10.1134/S2075113321050038 |
2021-09-01 | Purpose of Review This paper reviews various low-cost treatment techniques such as adsorption, permeable reactive barrier, and biological techniques for the simultaneous removal of chemical and microbial contaminants from groundwater and discusses treatment mechanisms of different treatment techniques. This paper also discusses the challenges of groundwater treatment, how to choose the appropriate treatment technique, and cost analysis of groundwater treatment. Recent Findings Various treatment technologies have been used for the treatment of groundwater: physical, chemical, and biological technologies with different success rates. In the literature, various adsorbents have been successfully synthesized from low-cost and environmentally friendly materials. Adsorption is considered an efficient treatment technique for the removal of both toxic elements and pathogens by utilizing different adsorbents. For example, the nanostructures of MgO with a BET surface area of up to 171 m 2 /g obtained a very high adsorption capacity of 29,131 mg/g for fluoride ions in water, while the incorporation of iron in activated carbon has improved its adsorption capacity to 51.3 mg/g for arsenic. Moreover, certain adsorbents have shown the capability to remove 99% of the rotavirus and adenovirus from groundwater. Summary Groundwater resources are contaminated with toxic metals and pathogens. Therefore, water treatment technologies should be evaluated for their efficiency to remove such contaminants. Determination of the most cost-effective and efficient treatment technique is not an easy task and requires the understanding of various aspects such as the contaminants present in water, the reuse options considered, and cost analysis of the treatment technique. | Removal of Toxic Elements and Microbial Contaminants from Groundwater Using Low-Cost Treatment Options | 10.1007/s40726-021-00187-3 |
2021-09-01 | Abstract One of the most important problems today is to solve heat-supply problems and simultaneously decide the problem of energy saving. Systems of low-temperature electric infrared heaters show high efficiency. Radiant heating systems have several advantages over traditional heating systems, like the possibility of heating both the entire room and separate zones, lack of massive pipelines and air ducts and the expenditure for heat-transfer agent transportation, and lack of dust and pollutant circulation in the heated room. Using radiant heating systems can also reduce air temperature in the heated room by 1–3°C due to features of heat-transfer processes when radiant heating is used and it is allowed by building standards. Thermal comfort in rooms with radiant heating devices is created by increase in the radiation temperature of the enclosing structures' internal surfaces with a simultaneous decrease in the internal air temperature. In this case, it is necessary to achieve compliance with the first thermal comfort conditions. In order to determine whether these requirements are met and whether they comply with the current building standards, it is necessary to develop a method for calculating heat transfer in rooms with radiant heating. It is necessary to develop a methodology that will take into account all the variety of heating device configurations. The most important parameters are the dimensions of the devices, the surface temperature, and their number and location in the serviced rooms. It is also necessary to take into account the geometric parameters of premises and the material and emittance of the inner surface of enclosing structures. Heating devices for residential and public buildings are considered in the article. Due to the low height of such premises, devices with surface temperatures up to 100°C are accepted for meeting the second thermal comfort condition. The developed method has a number of assumptions that gives an error not exceeding five percent. | Determining Temperature of Adiabatic Surfaces in Rooms with Radiant Heating | 10.1134/S0040601521090081 |
2021-09-01 | Ecologically and economically harmful wood borers and bark beetles, which have the capacity to expand geographically through the international log trade, require mitigations to prevent their spread. Detailed phenological knowledge of these pests across the wood-product supply chain can support systems approaches to phytosanitary risk management. Forest insect activity from 3.5 years of monthly, fortnightly, and daily sampling in recent clearfells from eight Pinus radiata plantation regions throughout New Zealand is presented. Phenology varied regionally with some species absent from specific regions. Insect activity declined with postharvest duration to a hypothesised background activity level that may be determined by landscape dispersal processes. Maximum temperature was the strongest predictor of flight activity with a 15 °C threshold that increased the probability of flight. Probability of a flight event was calculated for each species at monthly, fortnightly, and daily periods. Although wintertime activity was low, operationally effective temporal periods of low pest prevalence could not be defined on a monthly basis. Assurance of temporal periods of low pest prevalence as part of a systems approach will require additional supporting evidence of the relationship between forecast weather on short temporal scales (days), the probability of flight, and the relationship between low-level flight activity and the risk of wood product infestation by dispersing insects. | Large-scale, multi-year, phenology modelling of forest insects in Pinus radiata plantations | 10.1007/s10340-021-01328-9 |
2021-09-01 | SAPO-34 were synthesized using three structure-directing agents (SDAs), i.e., tetraethylammonium hydroxide (TEAOH), triethylamine (TEA), and morpholine (MO). These SAPO-34 supports were used to prepare Cu/SAPO-34 catalysts via two different Cu-exchange methods: incipient wetness impregnation (IWI) and solid-state ion exchange (SSIE). The catalytic performance of Cu/SAPO-34(TEAOH, TEA, MO) catalysts prepared with IWI and SSIE before and after exposure to water vapor at 70 °C was systemically examined, and their deactivation behavior during low-temperature NH 3 -SCR reaction was studied. These catalysts were characterized by XRD, BET, ICP-SFMS, SEM/EDX, solid-state NMR, CO-DRIFTS, NO-DRIFTS, and H 2 -TPR. The various characterization findings for the Cu/SAPO-34 catalysts suggest that the distribution of different Cu 2+ species and the mobility of Cu 2+ in chabazite (CHA) structure are important for the low-temperature deactivation and regeneration behaviors of the Cu/SAPO-34(TEAOH, TEA, MO)-IWI and -SSIE during the NH 3 -SCR reaction. Thus, it has been determined that the choice of SDA and Cu-exchange method is vital to design of an efficient Cu/SAPO-34 catalyst that is highly active during a NH 3 -SCR reaction and has a high tolerance for the low-temperature deactivation caused by exposure to water vapor. | Impact of Different Synthesis Methods on the Low-Temperature Deactivation of Cu/SAPO-34 for NH3-SCR Reaction | 10.1007/s40825-020-00182-y |
2021-09-01 | Abstract Nano-bainitic steels have attracted great attention for good wear resistance. In this research, a medium-carbon low-alloyed steel was austempered at a low temperature close to its martensite-start temperature for various times to obtain mixed microstructure of nano-bainite, martensite and retained austenite. The austempered samples were characterised comprehensively by field-emission SEM and quantitative XRD. Its two-body abrasive wear property was evaluated by sliding on a SiC abrasive disc. The results revealed the formation of initial nano-width carbide-free bainitic ferrite (BF) after austempering by 10 min, whereas the BF size and amount both increased with the austempering time. The austempered samples exhibited wear coefficients lower than the quenched martensitic sample by up to 50%. SEM and TEM observations showed wear mechanisms of micro-cutting and ploughing deformation, including the formation of a nano-laminate top layer and bending deformation in the subsurface multiphase microstructure. The decreased wear loss was attributed to the role of retained austenite in the increased plasticity. Graphic abstract | Effect of Short-Term Low-Temperature Austempering on the Microstructure and Abrasive Wear of Medium-Carbon Low-Alloy Steel | 10.1007/s12540-020-00957-6 |
2021-09-01 | The current study tested the hypothesis of whether the low-temperature catalytic cracking of waste plastics would generate carbon fules using high-density polyethylene (HDPE) polymer by potash as a novel catalyst for both energy recovery and carbon recycling. We applied a one-stage pyrolysis reactor system with a 75 min reaction time to observe the highest yield at a low temperature range of 70–170 °C. The effects of the potash and zeolite catalysts, temperature, and catalyst–polymer ratio on the pyrolysis liquid yield and hydrocarbon contents were determined. The mineral concentration of potash was analyzed semiquantitatively using an inductively coupled plasma-optical emission spectrophotometer (ICP-OES) and X-ray diffractometer (XRD). The ICP-OES demonstrated that nine metals, in the order of K > Na > Fe > Si > Mg > Al > Cu > Ca > Ni, were predominant in the potash. GC–MS analysis of the liquid products showed that major catalytic cracking molecules are C 11 to C 20 as kerosene- to diesel-range liquid. Potash catalyst produced an average liquid conversion of 34.7% at a catalyst ratio of 30 wt% over a distillate temperature range of 76–140 °C, whereas zeolite generated 19.5% at the same catalyst ratio over 90–120 °C. Although the two catalysts favored mainly olefinic products, a higher potash ratio promoted a smaller carbon products with a purer composition. Our experiments demonstrated that the new natural potash catalyst could convert waste plastics into kerosene to diesel range of valuable and recyclable liquid products as potential renewable fuel sources for carbon recycling. | Low-temperature synthesis of kerosene- and diesel-range fuels from waste plastics using natural potash catalyst | 10.1007/s40095-021-00387-z |
2021-09-01 | The electro- and plasmadynamic parameters of a high-frequency discharge at a low pressure (13.3–200 Pa) with a gas blowing-through are investigated in a nonlocal approximation. A discharge in a cylindrical discharge tube in a medium of argon is considered. The flow at the beginning of the discharge tube occurs in the regime of a continuous medium, whereas in the region of a plasma bunch and further downstream the flow regime changes to a freemolecular one. In this connection, a hybrid mathematical model is constructed that includes the Boltzmann equation for a neutral gas and the balance equations of the concentration and energy of electrons in the continuous medium approximation. The equations for the plasma particles are supplemented by the Maxwell equations transformed into the equations of telegraphy in the high-frequency electric intensity. The results of calculations of the electric intensity, concentration of electrons, and of electron temperature in the discharge tube are presented. It is shown that account for the nonlocality is an essential factor in simulating the high-frequency inductive discharge with gas injection ensuring effective transfer of charged particles from the field of their generation to the working chamber. | Mathematical Simulation of a High-Frequency Low-Pressure Discharge with Gas Injection in Non-Local Approximation: Electro- and Plasmadynamics | 10.1007/s10891-021-02415-5 |
2021-09-01 | This study was carried out to assess antioxidant activities and defense role of putrescine and proline in leaves of three Citrus species under low temperature stress. Branches of three Citrus species ( C. reticulata L., C. sinensis L. and C. paradisi L. ), sprayed with putrescine 0, 5, 10 mM and proline 0, 15, 20 mM. 24 h after application, containers containing treated shoots exposed to temperatures 1, − 1 and − 3 °C for six hours. The amount of hydrogen peroxide, flavonoids, phenolic compounds and antioxidant capacity increased with temperature reduction to − 3 °C. HPLC analysis showed that low temperature (− 3 °C) induces the levels of Gamma Aminobutyric Acid (GABA) in leaves of all species. The comparison of the HPLC patterns of the three species showed that GABA levels in treated leaves increased than control. The application of different concentrations of putrescine and proline decreased production of hydrogen peroxide but improved antioxidative activities of leaves under low temperatures. Putrescine 10 mM and proline 20 mM showed the highest effects than the other levels. The highest value of hydrogen peroxide was observed in leaves of control (putrescine and proline 0 mM) under − 3 °C but its lowest level was seen in leaves treated with proline 20 mM and putrescine 10 mM in all three species of Citrus . The highest level of phenolic compounds, flavonoids and antioxidant capacity were observed in leaves treated with putrescine 10 mM and proline 20 mM at − 3 °C. Putrescine 10 mM and proline 20 mM showed the highest impact on reduction of the damages caused by low temperature stress. | Effect of putrescine and proline on proflies of GABA, antioxidant activities in leaves of three Citrus species in response to low temperature stress | 10.1007/s13562-020-00645-x |
2021-09-01 | A simple monitoring method for observing slope movement and deformation can be performed with tilt sensors. A more efficient monitoring method, using a type of wireless communication called LPWA (low-power wide area) network technology, has also recently become available. In the present study, a monitoring system was developed that combines tilt sensors and LPWA network technology for measuring the movement of slopes and sending the information through wireless communication. First, radio wave propagation experiments were conducted to find the proper location for the gateway device of the monitoring system. Then, in March 2018, the developed system that consists of tilt and water-level sensors and the wireless communication of LPWA was installed at an observation site. Since the installation, the data from the tilt sensors have been successfully collected through LPWA, and a slope failure was unexpectedly observed at the observation site during the Heavy Rain Event of July 2018, which caused severe disasters, particularly from western Japan to the Tokai region. Using the data from the tilt sensors, the rainfall data, and the groundwater level, the slope failure was analysed. A site investigation was conducted, and the shear strength parameter was examined using back analysis method. In conclusion, the developed system using sensors and LPWA has continued to efficiently monitor the movement of the targeted slope, but the collection of additional data will be required to increase the reliability of the system. | Development of slope deformation monitoring system based on tilt sensors with low-power wide area network technology and its application | 10.1007/s13349-021-00494-9 |
2021-09-01 | Abstract: The fused-cast refractory is the key lining material for glass furnaces; Its high corrosion resistance and low thermal conduction, which are determined by the phase structure, are a main focus of its development. In this paper, the relationship between the phase composition, the thermal conductivity and the corrosion resistance to glass-liquid was investigated by means of numerical simulation combined with a melting test. A phase structure and thermal conductivity corrosion resistant model with a eutectic content of 40-70 % and an average equivalent eutectic grain size 5-25 μm was established. It shows that the uniformity of thermal insulation and corrosion resistance of the material can be achieved by increasing the eutectic content and refining the eutectic grains. At the same time, by using a computer-controlled melting process, low thermal conductivity and high corrosion resistance of fused-cast AZS refractories can be produced, which can improve the energy saving effect with a glass furnace insulation and a safe operation time. | Relationship Between Phase Composition, Thermal Conductivity and Corrosion Resistance of Fused-Cast AZS Refractories | 10.1007/s42411-021-0458-8 |
2021-09-01 | Physicochemical and microbiological parameters of Turkish blossom honey after cold atmospheric gliding arc discharge (GAD) plasma, non-thermal ultrasound, and low-temperature oven treatments were investigated. For this purpose, a full-factorial design method was employed to optimize plasma and ultrasound treatment conditions on 5-hydroxymethyl-2-furfural (HMF) reduction in honey. Results showed that air-GAD plasma operated at 0.3 mL/min of gas flow rate (GF) with a 0.3 cm copper electrode tip distance (ED) for 30 min, nitrogen-GAD plasma operated at 0.4 mL/min of GF with 0.5 cm ED for 30 min, and non-thermal ultrasound operated at 40% amplitude for 5 min significantly decreased HMF in honey samples ( p < 0.05). The optimal conditions for non-thermal ultrasound, nitrogen-GAD and air-GAD plasma treatments reduced HMF by 19%, 32%, and 37%, respectively ( p < 0.05) while low-temperature oven treatment at 55 °C for 7 h caused no significant change in HMF compared to untreated honey (control) ( p > 0.05). On the other hand, diastase activity was significantly increased after non-thermal ultrasound and oven treatments by up to 47–57% ( p < 0.05) compared to control. Nitrogen-GAD plasma is recommended over other treatments not only because it was effective in decreasing HMF (32%), free acidity (22%), moisture (41%) value, and osmophilic yeast count (100%) and increasing maltose (31 %) and L* (40) values but also because it maintained diastase and antiradical activities, soluble phenolic content, glucose, fructose, pH, and a* and b* values of the honey. | Effects of Cold Atmospheric Gliding Arc Discharge Plasma, Non-thermal Ultrasound, and Low-Temperature Oven Treatments on Quality Parameters of Turkish Blossom Honey | 10.1007/s11947-021-02688-x |
2021-09-01 | Abstract A series of Ni-Al 2 O 3 catalysts with attractive catalytic activity and thermal stability have been developed via a facile hydrolysis-precipitation technique (xNiAl-HP, x representing the weight percentage of NiO). Based on the high nickel active surface area, good dispersion of NiO and high content of α- and β 1 -type NiO, outstanding CO conversion (99%) and CH 4 yield (96%) can be achieved over 40NiAl-HP under mild conditions [T = 220 °C, P = 1.0 MPa, and WHSV = 20,000 mL/(g·h)]. The reaction-sintering at high temperature (800 °C) evolves through: (a) the migration of nickel crystals, (b) the phase transformation from γ- to θ- and then to α-Al 2 O 3 , and (c) the agglomeration of catalyst particles. The 40NiAl-HP catalyst could still maintain CO conversion over 99% at 300 °C after being used at 800 °C for 100 h. Herein, the high catalytic activity, good sintering resistance and noble-metal-/promoter-free nature might make 40NiAl-HP a competitive candidate for industrial methanation. Graphic Abstract | Development of Highly Stable Ni-Al2O3 Catalysts for CO Methanation | 10.1007/s10562-020-03486-4 |
2021-09-01 | An equiatomic Mg 20 Al 20 Si 20 Cr 20 Fe 20 (at.%) low-density high-entropy alloy (LDHEA) was synthesized by mechanical alloying (MA) and consolidated by spark plasma sintering (SPS) techniques. The phase identification, chemical composition, fine microstructural features and thermal stability of the mechanical alloyed powder and the spark plasma sintered (SPSed) compacts were discerned through X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and differential scanning calorimetry (DSC) techniques. The LDHEA powder after mechanical alloying for 60 h exhibited a nanocrystalline BCC phase ( a = 0.2887 ± 0.005 nm) as a major one along with the minor fraction (~ 3%) of undissolved Si. The 60-h milled powder was consolidated through SPS at 800 ℃ (1073 K). The SPSed sample exhibited the presence of a major B2-type AlFe phase (cP2; a = 0.2889 nm) along with a parent disordered BCC phase and a minor amount of Al 13 Fe 4 (mC102; a = 1.549 nm, b = 0.808 nm, c = 1.248 nm), β -Al 3 Mg 2 (cF1168; a = 2.824 nm) and Cr 5 Si 3 (tI32; a = 0.917 nm, c = 0.463 nm) phases. Attempts were made to explore the mechanical properties of the LDHEA through microindentation techniques. The hardness and yield strength were evaluated to be ~ 7 GPa and ~ 2100 MPa respectively. The density of the sintered sample was found to be around 4.38 g cm −3 , which is around 99.98% of the theoretical density. The phases evolved during MA and SPS were explained with the help of the thermodynamic parameters and property diagrams generated through the CALPHAD approach using Thermo-Calc software. | Fabrication of MgAlSiCrFe Low-Density High-Entropy Alloy by Mechanical Alloying and Spark Plasma Sintering | 10.1007/s12666-021-02262-1 |
2021-09-01 | Exposures of arc crustal sections represent rare opportunities to directly evaluate lower crustal magmatic processes and their link to arc products in the middle and upper crust. Within the southernmost Sierra Nevada batholith, the Bear Valley Intrusive Suite (BVIS) exposes a contemporaneously constructed ~ 30 km thick intrusive suite, and thus is ideal for this type of examination. Here we present detailed petrography and mineral major and trace element data for the BVIS. The deepest exposed portion of the BVIS (8–9 kbars) is composed of heterogeneous mafic igneous intrusions of olivine metagabbro, olivine-hornblende orthopyroxenite, olivine-bearing hornblende norite, hornblende norite, hornblende gabbronorite, hornblendite and hornblende gabbro. Shallower crustal intrusions (3–7 kbars) are comparatively homogeneous and dominated by hypersthene-bearing and hypersthene-free tonalites. Using amphibole-plagioclase geothermometry, we show that the mafic lower crustal intrusions crystallized over a wide temperature range from 850 to 1070 °C, highlighting mafic igneous fractionation during isobaric cooling in the lower crust of the Sierran arc, while tonalitic liquids were emplaced at temperatures < 800 °C in the middle and upper crust. Calculated trace element melt compositions in equilibrium with amphibole in lower crustal gabbros are similar to measured tonalite bulk compositions and support the generation of tonalites through fractionation of the observed gabbros. Further, petrography and mineral chemistry suggest multiple distinct crystallization sequences recorded in the different types of gabbro, requiring the presence of coexisting parental melts with contrasting compositions and H 2 O contents. Using available experimental data, we develop a model by which mixing of variably fractionated dry and wet magmas with similar viscosities followed by crystallization-differentiation in the deep crust to explain the formation of uniform tonalitic melts at shallower crustal levels in the BVIS. This process also explains the unusual predominance of orthopyroxene in the BVIS, and the limited aluminum enrichment compared to experimental differentiation sequences of hydrous basalts. Considering the similar geochemical characteristics of intermediate and felsic igneous rocks from the Sierra Nevada batholith and the Cascades, mixing magmas of variable H 2 O contents in the lower crust represents a viable petrological process to produce SiO 2 -rich liquids that may be more common than previously recognized. | Mixing dry and wet magmas in the lower crust of a continental arc: new petrological insights from the Bear Valley Intrusive Suite, southern Sierra Nevada, California | 10.1007/s00410-021-01832-2 |
2021-09-01 | Abstract In this paper, we study the morphology of the bainite component of the microstructure of rolled products and the mimic coarse-grained region of the thermal effect zone of K60–K65, 09G2S, and 08KhN2MFB low-carbon steels by methods of optical microscopy and electron backscatter diffraction. In the homogeneous microstructure of the former austenite—both in the coarse-grained heat-affected region and in rolled products—the density of high-angle grain boundaries is shown to be higher in lath bainite than that in granular bainite. In the case of a substantially inhomogeneous microstructure of the former austenite, the size effect of the initial grain structure on the effective grain size (high-angle boundaries) prevails over the change in the bainite morphology. The lower-temperature component, lath bainite, turns out to be coarser-grained (in the case of its formation from large-sized austenite grains) than granular bainite. The impact viscosity and cold resistance of a metal, the microstructure basis of which is a mixture of granular and lath bainite, increased at an increase in the density of high-angle boundaries, which in turn is determined by both the grain size of the initial austenite and the morphology of bainite. | Questioning the Effect of Bainite Morphology on the Impact Viscosity of Low-Carbon Steels | 10.3103/S0967091221090035 |
2021-09-01 | Abstract An experimental stand is developed to study the hydrodynamics of the oil-supercritical CO 2 flow in a homogeneous porous terrigenous medium at pressures up to 25 MPa and temperatures up to 473K. The experimental stand allows measuring the solubility of carbon dioxide in oil and oil in carbon dioxide in the process of the unsteady filtration of the oil-supercritical CO 2 system in a low-permeability homogeneous porous medium in a dynamic mode. The solubility of the model low-viscosity oil when it is displaced from the model of a terrigenous homogeneous oil reservoir and the dynamic viscosity of the liquid oil-supercritical CO 2 substance are studied. Based on the obtained experimental data on the thermophysical properties of the oil-supercritical CO 2 system, a mathematical model is developed for the process of the unsteady filtration of the oil-supercritical CO 2 flow in a low-permeability homogeneous porous medium. The problem is solved numerically by the finite difference method. An implicit scheme in terms of pressure and an explicit scheme in terms of saturation, the so-called IMPES method, is used in the discretization process. At each moment of time, the pressure is calculated from a system of linear equations while the saturation is taken from the previous time layer. Then the saturation is recalculated explicitly using the found pressures. When discretizing the derivative for the adjacent nodes, the permeability is taken from the node in which the pressure is higher (that is, the upstream scheme is used). The convergence of the solution is controlled by performing numerical experiments on condensed grids. The developed mathematical model makes it possible to calculate the values of the displacement coefficient of the real oil. The mechanisms of enhanced oil recovery from permeable and low-permeability porous media are identified. | Unsteady Filtration of the Oil-CO2 Flow in a Homogeneous Reservoir under Different Thermobaric Conditions | 10.1134/S2070048221050185 |
2021-09-01 | Rice is the basic food for over half the global population. Paddy cultivation is limited by environmental stressors, which tend to worsen with climate change. In addition, an increase in food demand is expected soon. Therefore, innovative agricultural technologies capable of increasing food production without increasing agricultural frontiers are needed. Some microorganisms can confer plant tolerance to environmental stresses; however, research with rhizospheric bacteria inducing cold tolerance in rice plants is scarce. In this work, we evaluated the prokaryotic community of cold-impacted rice paddies and the ability of selected rhizospheric bacteria towards increasing rice tolerance to cold temperatures without resulting in yield penalties. The most abundantly identified phyla (Proteobacteria, Acidobacteria, and Actinobacteria) are common soil bacteria, which harbor most plant growth-promoting bacteria (PGPB) and should be responsible for plant protection from abiotic stresses, such as low temperature. From these soils, nine PGPB were selected and inoculated in cold-stressed rice plants, and two ( Kosakonia sp. CIR2 and Staphylococcus sp. CSR1T2) were able to confer cold tolerance to rice plants. These cold-stressed plants inoculated with CIR2 and CSR1T2 presented higher survival rates (69% and 85%, respectively) than non-inoculated plants (33%). In the greenhouse, cold-stressed inoculated plants reached the reproductive cycle approximately 25 days earlier than non-inoculated plants, besides presenting increased fertility (percentage of full seeds/full seeds per plant) and improvement in yield parameters (weight of 1,000 full seeds, grain length, seed weight per plant, and seed yield). These data can contribute to the improvement of inoculation practices in rice plants and to the maintenance of rice production in environments impacted by low-temperature stress in early developmental stages. | Rhizospheric Soil from Rice Paddy Presents Isolable Bacteria Able to Induce Cold Tolerance in Rice Plants | 10.1007/s42729-021-00496-y |
2021-09-01 | Abstract The developments in the field of low-noise receiving systems in the sub-THz range, performed at the Kotelnikov Institute of Radio Engineering of the Russian Academy of Sciences in recent years and aimed at the creation of receivers with quantum sensitivity for space and ground-based radio telescopes are presented. Superconductor–insulator–superconductor (SIS) mixers based on high-quality tunnel junctions are key elements of the most sensitive sub-THz heterodyne receivers. The article presents the results of the development of SIS receivers in the 211–275 GHz and 800–950 GHz ranges with a noise temperature in the double-sideband (DSB) mode of about 20 K and 220 K, respectively. These achievements will be used to develop receiving systems for APEX and LLMA ground-based telescopes, as well as for the Millimetron space mission. | Superconducting Sub-THz Receivers for Space and Ground-Based Radio Astronomy | 10.3103/S1068335621090062 |
2021-09-01 | In this study, experimental and numerical investigations were carried out in order to determine the mechanical properties and impact response of hybrid composite laminate. The hybrid composite laminate was formed from plain woven carbon fiber reinforced epoxy (CFRE) and plain woven glass fiber reinforced epoxy (GFRE) fiber using VARTM (vacuum-assisted resin transfer molding) process. The mechanical properties of the hybrid composites were determined using tensile test device with a 1 mm/min loading rate at room temperature. In addition, hybrid composites were subjected to low-velocity impact test under different impact energy levels (10, 20, 30, 40 J) for determining the impact response. Moreover, mechanical properties and impact responses of CFRE and GFRE laminates were also determined to compare to those of hybrid composite (HCGFRE). Microstructure analysis was performed to investigate the damage surfaces of the fiber and matrix in the composite material subjected to impact and tensile forces. In numerical analyses, composite damage model (Mat 54) was utilized in LS-DYNA ® explicit finite element program to simulate the impact behavior of CFRE, GFRE and HCGFRE laminates. Consequently, the tensile test results showed that hybrid composite laminate behaved more ductile than carbon composite laminate and it exhibited more brittle behavior than glass composite laminate. Also, it was determined that absorbed energy and impact load capacity of HCGFRE composite laminate are between absorbed energy and impact load capacity of CFRE and GFRE composite laminate. It was determined that numerical results indicate a similar tendency with the experimental results. | An Experimental and Numerical Determination on Low-Velocity Impact Response of Hybrid Composite Laminate | 10.1007/s40997-020-00402-4 |
2021-09-01 | Precipitation strengthening of nano-scale TiC is a promising method to improve mechanical properties of Fe–16Mn–9Al–0.8C (wt.%) low-density steel. This work attempted to introduce nano-scale TiC precipitates by adding 1 wt.% Ti element. The experimental results show that these precipitates with the total fraction of about 2 vol.% were formed and no coarse precipitates were observed despite the high Ti addition. It was interesting that the polygonal and needle-shaped TiC precipitates were observed in γ-austenite and δ-ferrite, respectively. Ti addition also decreased the volume fraction of γ-austenite significantly. Correspondingly, the yield strength was increased, but the elongation was significantly decreased due to the significant decrease of γ-austenite. Comparing with the Ti-free steel, the formation of TiC precipitates was the main reason for the increase in yield strength of Ti-bearing steel, and TiC precipitates also led to a higher strain hardening index at the first deformation stage. TiC precipitates promoted the Orowan strengthening, resulting in a higher strain hardening capability than Ti-free steel reinforced by shearable κ-carbide. | Precipitation strengthening of nano-scale TiC in a duplex low-density steel under near-rapid solidification | 10.1007/s42243-020-00511-z |
2021-09-01 | Organo-inorganic hybrid materials based on inorganic oxyfluoride lead-borosilicate glass matrices and the metal-complex compound tris-(8-oxycholate) ytterbium (III) were obtained by the melt method. The spectral-luminescence properties of tris-(8-oxycholate) ytterbium and hybrid materials in the visible and IR ranges were studied under different excitations (377 and 785 nm). It is shown that the intensity of IR luminescence in the initial metal-complex luminophore surpasses the luminescence in the visible range and vice versa in the obtained hybrid materials — the intensity of visible luminescence significantly surpasses the IR-luminescence. | Infrared Luminescent Hybrid Materials Based on Inorganic Glass Matrices | 10.1007/s10717-021-00382-0 |
2021-09-01 | Abstract The effect of iron oxide additives on the formation of the microstructure of supported 1 wt % Pt/(Fe 2 O 3 –TiO 2 ) catalysts, the electronic state of platinum, and the catalytic properties of the catalysts in the CO oxidation reaction has been studied. The synthesized catalyst has exhibited a higher activity than that of a 1 wt % Pt/TiO 2 catalyst at identical amounts of platinum in the samples. It has been found that the introduction of iron oxide in an amount of up to 10 wt % leads to the formation of a solid solution of iron ions in titania with an anatase structure. The supporting of platinum has led to a decrease in the particle size and an increase in the content of platinum in the Pt δ+ state. An optimum chemical composition of the catalyst that provides the highest activity in the studied reaction has been determined. | Synergetic Effect of an Iron Oxide Additive to the Composition of a Support for a Pt/TiO2 Catalyst in the Carbon Monoxide Oxidation Reaction | 10.1134/S0023158421050104 |
2021-09-01 | Photodynamic therapy (PDT) is a treatment that uses light-sensitive drugs and a light source to destroy cancer cells. Methylene blue (MB) is an efficient photosensitizing agent that has been widely used in PDT. However, MB suffers from the hypochromic effect that is caused by self-aggregation and DNA binding in vivo . It is also easily reduced to ineffective leucomethylene blue in the hypoxic environments surrounding solid tumors. In this work, we prepared MB carbon dots (MB-CDs) using MB as the carbon source. The MB-CDs not only inherit the PDT capabilities of MB, but also demonstrate good biocompatibility and low toxicity. Importantly, MB-CDs demonstrate excellent resistance to interference from reduction, aggregation, and DNA interactions. The MB-CDs exhibited satisfactory PDT activities both in vitro and in vivo . The tumor sizes were reduced to below 20% of their original volumes when irradiated by a 590-nm light-emitting diode source. 光动力疗法(PDT)是一种重要的癌症治疗手段, 亚甲基蓝 (MB)作为一种有效的光敏剂被广泛应用于光动力治疗. 然而, MB 在体内由于聚集以及与DNA结合而导致减色效应. 同时, MB在实 体瘤的低氧环境中容易被还原为无色的还原态leucoMB, 从而丧失 光动力能力. 因此, 我们以MB作为碳源, 制备碳点MB-CDs. MBCDs 不仅继承了MB的PDT能力, 而且表现出良好的生物相容性和 低毒性. 重要的是, MB-CDs具有出色的抗还原、抗聚集和抗DNA 干扰的能力, 并且MB-CDs在体外和体内均表现出良好的PDT活性, 仅用590 nm LED光源照射一次, 即可使肿瘤体积减小到原始体积 的20%以下. | Photodynamic inheritance from methylene blue to carbon dots against reduction, aggregation, and DNA interference | 10.1007/s40843-020-1623-4 |
2021-09-01 | The remarkable mechanical characteristics of sandwich lattice structures have attracted the attention of many researchers and make it a good candidate for various applications. However, there is limited published research concerning the development of general-purpose dynamic models mimicking the impact behavior of lattice configurations made from polymeric materials. As such, the main focus of this research is to develop efficient computational finite element models simulating the dynamic impact behavior of various lattice configurations embedded in sandwich panels that are made from Acrylonitrile Butadiene Styrene (ABS) material. In this case, the sandwich panel consists of a 3D-printed polymer lattice core covered with the skin of a Kevlar sheet. Four designs with different configurations of lattice structures were investigated experimentally in previous studies. The first configuration was the basic body centered cubic (BCC) with unit cell dimensions of 5 mm × 5 mm × 5 mm, and a strut diameter of 1 mm. The second configuration was produced by adding the vertical struts at alternative nodes layer by layer, referred to as BCCA. The third configuration was created by adding the struts with uniform gradient distributions, termed as BCCG. The last configuration was designed by adding vertical struts at all nodes on the BCC configuration, denoted as BCCV. In this research, the FEA software ABAQUS Explicit was used to model all four configurations under low-velocity impact loads. Then, the results from the FEA modeling of the four different sandwich structures were compared with the experimental observations. Significantly, the good agreement in the results between the FEA and the experimental work reveals the capability of the developed models to capture the dynamic impact behavior of various lattice configurations and is considered the main contribution of the current research. In addition, in situ deformation along with failure mechanisms, detailed information, visualization, and sufficient data of the lattice impact test has been obtained through the developed models. This in turn leads to saving human time and effort, providing better realization and deep analysis of impact deformation behavior reducing the size of the experimental work and the expenses associated with it. | A Computational Approach in Understanding the Low-Velocity Impact Behavior and Damage of 3D-Printed Polymer Lattice Structures | 10.1007/s11665-021-05873-3 |
2021-09-01 | Abstract The study of the influence of electron-beam treatment on the structural features of a TiNi powder alloy obtained by calcium-hydride reduction is carried out. It is found that electron-beam treatment leads to homogenization of the phase and chemical composition of the surface layer of the TiNi powder alloy, smoothing of the surface relief of TiNi powder particles, and the healing of the defects on their surface. It is shown by energy dispersive X-ray spectral microanalysis that the concentration of Ti in the surface layer increases. This is due to recrystallization of this layer containing Ti 2 Ni particles during its remelting under the influence of the high energy density of the electron beam during treatment. | The Influence of Electron-Beam Treatment on the Structure of a TiNi Powder Alloy Obtained by Calcium-Hydride Reduction | 10.1134/S1027451021050244 |
2021-09-01 | The current study investigates the fitness cost associated with phosphine resistance in the rusty grain beetle, Cryptolestes ferrugineus (Stephens), a problematic pest in the stored commodities that has developed strong resistance to fumigant phosphine. Three characterised insect strains: the susceptible (Ref-S), the strongly resistant (Ref-R), the introgressed resistant (Intro-R) and a segregating population ( F 25 ) derived from crossing the Ref-S and Ref-R strains were used in this study. Intro-R was developed by introgressing two phosphine resistance genes, cf_rph1 and cf_rph2 into Ref-S, aimed to reduce the influence of background genetic factors. Intro-R exhibited 592 × resistance to phosphine and homozygous for strong resistance allele, cf_rph2 (L73N). Two key fitness cost criteria, developmental time and fecundity, were assessed under optimal and suboptimal conditions (less favourable diet and low temperature). There was no significant difference in developmental time and fecundity between Ref-S and either Intro-R strain or F 25 under optimal conditions. When challenged with a less favourable diet, cracked wheat + cracked sorghum (CW + CS), or exposed to a low temperature (22 °C), both Intro-R and Ref-S had similar developmental time and total numbers of F 1 progeny, confirming the absence of significant fitness effects expressed in these conditions. Therefore, we conclude that strongly phosphine resistant C. ferrugineus are unlikely to incur potential fitness costs. This finding will have implications towards developing strategies to manage this pest. | Gene introgression in assessing fitness costs associated with phosphine resistance in the rusty grain beetle | 10.1007/s10340-020-01315-6 |
2021-09-01 | Hydrogel has been widely used in the research of bionic articular cartilage due to their similarity in structure and functional properties to natural articular cartilage. In this research, polyvinyl alcohol and betaine monomer were used as raw materials to prepare a high-strength double-network hydrogel by a combination of ultraviolet (UV) irradiation and freeze–thaw methods. The structure of samples was characterized by Fourier transform infrared spectroscopy and X-ray diffraction, and the morphology of the samples was characterized by scanning electron microscope and three-dimensional white light interferometer. In addition, we also studied the swelling ratio, water content, mechanical properties and tribological properties of the samples. We found that the addition of betaine monomer and the UV irradiation time had a positive effect on the mechanical properties and tribological properties of the samples. | Mechanical and Tribological Study of PVA–pMPDSAH Double-Network Hydrogel Prepared by Ultraviolet Irradiation and Freeze–Thaw Methods for Bionic Articular Cartilage | 10.1007/s42235-021-00079-8 |
2021-09-01 | Abstract Electro-deoxidation of ilmenite (FeTiO 3 ) is an economical production method of FeTi, particularly, if the end use is hydrogen storage. In this study, we show that electro-deoxidation of impure FeTiO 3 with Ti content lower than Fe, as in the case of low-grade FeTiO 3 ore, results in the formation of a two-phase material consisting of FeTi and Fe 2 Ti. The presence of Fe 2 Ti is detrimental to the hydrogen storage efficacy. We show for the first time that it is possible to avoid the formation of Fe 2 Ti or β-Ti as a second phase under similar operating conditions only by tailoring the composition of the cathode precursor, i.e., the addition of TiO 2 to low-grade FeTiO 3 so that the atomic ratio of Fe:Ti in the precursor is ~ 1:1. Low-grade FeTiO 3 with 10 wt% TiO 2 resulted in single-phase FeTi with the atomic ratio of Fe:Ti ~ 1:1 in the precursor and in the final reduced alloy. The hydrogen storage capacity of the single-phase FeTi is nearly 36% higher as compared to the two-phase alloy consisting of FeTi–Fe 2 Ti. Graphical Abstract | Electro-deoxidation Process for Producing FeTi from Low-Grade Ilmenite: Tailoring Precursor Composition for Hydrogen Storage | 10.1007/s40831-021-00412-9 |
2021-09-01 | A numerical study was performed to investigate the combustion characteristics of hydrogenated catalytic biodiesel (HCB)/gasoline reactivity controlled compression ignition (RCCI) with dual-fuel direct injection at low load condition. The results indicated that compared with the conventional port injection RCCI, the dual-fuel direct injection can effectively control the distribution of in-cylinder gasoline mixture and improve the incomplete combustion phenomenon. The delay of start of injection (SOI) of gasoline can weaken stratified combustion, shorten combustion duration, reduce combustion efficiency, decrease NOx emission and increase soot emission. In contrast, the delay of SOI of HCB can intensify stratified combustion, prolong combustion duration, increase combustion efficiency, increase NOx emission and reduce soot emission. Compared with gasoline injection timing, HCB injection timing has a more profound effect on combustion efficiency and indicated thermal efficiency. When HCB injection timing was in the range of -25° ATDC (after top dead center) to -20° ATDC and gasoline injection timing of -50° ATDC to -45°ATDC, the engine has a better performance, with the combustion efficiency about 94 %, the indicated thermal efficiency around 45 %, and the NOx and soot emissions in the original exhaust less than the limit value of Euro VI standard. | Numerical investigation of dual-fuel direct injection on RCCI combustion performance at low load condition | 10.1007/s12206-021-0835-2 |
2021-09-01 | The multiple forms of vibration exist in an ambient environment diffusely and already become a considerable object for energy harvesting. However, how to effectively extract low-level, low-frequency, and multi-directional vibration from the ambient environment is becoming a key issue in the field of energy harvesting. To solve this issue, a tower-shaped piezoelectric vibration energy harvester (TS-PVEH) is reported. Finite element simulation indicates that TS-PVEH works in two fundamental modes, i.e., its in-plane and out-of-plane vibration modes. Meanwhile, simulation results show that the natural frequency of TS-PVEH is 3.39 Hz, 3.40 Hz, and 11.50 Hz, respectively; and the experiments also verified that. By virtue of the tower structure of TS-PVEH, the device is pretty sensitive to three-dimensional vibration. At a low level of acceleration 1 m/s 2 , the maximum load power of TS-PVEH is 65.8 µW in out-of-plane mode and 17.2 µW in in-plane mode, respectively. Furthermore, the effects of the PVDF connection mode on the output performance of TS-PVEH were studied in detail, and comparative experimental results show that a reasonable connection of PVDF can improve energy harvesting efficiency. The proposed TS-PVEH is expected to be used to scavenge energy from multi-dimensional, low-level, and low-frequency vibrations that present in an ambient environment. | A Tower-Shaped Three-Dimensional Piezoelectric Energy Harvester for Low-Level and Low-Frequency Vibration | 10.1007/s40684-020-00281-9 |
2021-09-01 | To reveal the tectonic characteristics of the continental margins in the southwest subbasin (SWB) of the South China Sea, a long high-resolution seismic profile was studied using empty basin subsidence. We find that tectonic subsidence features on both margins are uniformly divided into three stages: (1) slow subsidence from Tg to 18.5 Ma (synrift stage); (2) extremely slow subsidence/uplift from 18.5 to 16 Ma (spreading stage); and (3) accelerated subsidence from 16 to 0 Ma (post-spreading stage). This feature differs from the classic tectonic subsidence pattern of rifted basins, which exhibits fast subsidence during synrift stage and slow subsidence during the post-rift stage. The tectonic uplift occurred during the spreading stage and the magnitude increased from the continent to the ocean, which is likely related to mantle flow during seafloor spreading. We propose that lower crustal flow played a significant role in the tectonic evolution of the continental margins of the SWB. The lower crust of the SWB margins was warmer and therefore weaker, and more prone to flow beneath the faulting center, which compensated for the upper crustal thinning caused by brittle faulting during the synrift period and thus reduced the tectonic subsidence rate. During the spreading stage, faulting attenuated rapidly, and a necking zone appeared at the continent-ocean transition formed by lithospheric extension. With upwelling asthenosphere, small-scale secondary mantle convection occurred under the necking zone, which raised the continental margin isotherms and increased the buoyancy. Simultaneously, secondary mantle convection lifted the overriding crust, thus the overall subsidence rate decreased sharply or even reversed to uplift. After seafloor spreading, the effect of mantle convection faded away, and sediment loading drove the lower crust to flow landward. Thermal relaxation, lower crust flow, and vanish of secondary mantle convection together led to rapid subsidence in this stage. | Three-stage tectonic subsidence and its implications for the evolution of conjugate margins of the southwest subbasin, South China Sea | 10.1007/s00343-020-0259-3 |
2021-09-01 | The recent development of 3D printers allowed a lot of limitations in the field of microfabrication to be circumvented. The ever-growing chase for smaller dimensions has come to an end in domains such as microfluidics, and the focus now shifted to a cost-efficiency challenge. In this paper, the use of a high-resolution stereolithography LCD 3D printer is investigated for fast and cheap production of microfluidic master molds. More precisely, the UV LED array and the LCD matrix of the printer act as an illuminator and a programmable photomask for soft lithography. The achieved resolution of around 100 μm is mainly limited by the pixel geometry of the LCD matrix. A tree-shape gradient mixer was fabricated using the presented method. It shows very good performances despite the presence of sidewall ripples due to the uneven pixel geometry of the LCD matrix. Any design can be brought from concept to realization in under 2 h. Given its sub-€1000 cost, this method is a very good entry point for labs wishing to explore the potential of microfluidic devices in their experiments, as well as a teaching tool for introducing students to microfluidics. | Cheap, versatile, and turnkey fabrication of microfluidic master molds using consumer-grade LCD stereolithography 3D printing | 10.1007/s00170-021-07329-3 |
2021-09-01 | Abstract The effect of modulation of the decay envelope of the echo signal of 57 Fe nuclei in lithium ferrite is studied experimentally, which demonstrates its intrawall origin. In contrast to cobalt characterized by a large modulating anisotropic component of the hyperfine field, which acts on nuclei in domain walls upon displacement of the latter, the manifestation of strong modulation effect in low anisotropic lithium ferrite with a relatively high mobility of domain walls is possibly caused by additional dynamic modulating effects associated with a high mobility of domain walls in this material. | A Study of the Nature of the NMR Signal in Lithium Ferrite upon Exposure to a Low-Frequency Magnetic Field | 10.1134/S0031918X21090088 |
2021-09-01 | Abstract— In recent years, the problem of global climate change has become one of the significant challenges for ensuring the sustainability of the functioning and growth in the market value of the world’s leading industrial companies. Based on the latest data, the article describes the scale and impact of climate change on the development of companies and also considers some corporate strategies for reducing climate risks and adapting to the consequences of climate change. It is shown that, acting as a significant factor in the financial losses of business, the growing climate change, at the same time, indirectly contribute to the acceleration of the environmentally oriented transformation of corporate management systems and technological modernization of production complexes, creating, in conjunction with other technological and production trends, new sources of long-term competitiveness and market value. The article presents the characteristics of the priorities in the state industrial policy in the context of climate change. | Climate Change as a Factor in the Development of Companies: Corporate Strategies and Guidelines for State Industrial Policy | 10.1134/S1075700721050130 |
2021-09-01 | The coronavirus disease 2019 (COVID-19) outbreak has made it necessary to rationalize health-care resources, but there is little published data at this moment regarding ambulatory management of patients with COVID-19 pneumonia. The objective of the study is to evaluate the performance of a protocol for ambulatory management of patients with COVID-19 pneumonia regarding readmissions, admission into the Intensive Care Unit (ICU) and deaths. Also, to identify unfavorable prognostic factors that increase the risk of readmission. This is a prospective cohort study of patients with COVID-19 pneumonia discharged from the emergency ward of Infanta Cristina Hospital (Madrid, Spain) that met the criteria of the hospital protocol for outpatient management. We describe outcomes of those patients and compare those who needed readmission versus those who did not. We use logistic regression to explore factors associated with readmissions. A total of 314 patients were included, of which 20 (6.4%) needed readmission, and none needed ICU admission nor died. At least one comorbidity was present in 29.9% of patients. Hypertension, leukopenia, lymphocytopenia, increased lactate dehydrogenase (LDH) and increased aminotransferases were all associated with a higher risk of readmission. A clinical course of 10 days or longer, and an absolute eosinophil count over 200/µL were associated with a lower risk. After the multivariate analysis, only hypertension (OR 4.99, CI 1.54–16.02), temperature over 38 °C in the emergency ward (OR 9.03, CI 1.89–45.77), leukopenia (OR 4.92, CI 1.42–17.11) and increased LDH (OR 6.62, CI 2.82–19.26) remained significantly associated with readmission. Outpatient management of patients with low-risk COVID-19 pneumonia is safe, if adequately selected. The protocol presented here has allowed avoiding 30% of the admissions for COVID-19 pneumonia in our hospital, with a very low readmission rate and no mortality. | A safe protocol to identify low-risk patients with COVID-19 pneumonia for outpatient management | 10.1007/s11739-021-02660-9 |
2021-09-01 | Abstract The world’s shortage of raw materials favoures the interest towards mineral waste materials as a potential source of valuable metals and minerals. In the past century, mining and metallurgical activities of copper mines and smelters in Albania (Kurbnesh, Reps, Gjegjan, Kukës, Rubik, Lac, Rreshen) storaged various waste materials as waste rocks, flotation tailings, metallurgical slags and residues. To date, these “environmental hotspots” occur in old abandoned tailings storage facilities in Albania and present a serious risk of environmental damages and disasters like dam failures, ground water and surface water pollution. Even displacements of dry fine materials containing heavy metals by wind, could result in a permanent pollution of the surrounding area and finally of the Adriatic Sea. This research presents the characterisation and processing of tailings material from abandoned tailings from Kurbnesh (Albania) using mineralogical, physical and chemical methods. The processed tailings mainly consist of sulfides (10 wt %), Mg, Ca, Fe silicates (46 wt %) and quartz (40 wt %). Copper (0.15 wt %) and cobalt (0.03 wt %) were determined as major valuable metals and are distributed in chalcopyrite, cobaltite and cobaltiferous pyrite. These sulfide minerals were recovered by a collective flotation, followed by a selective flotation of the copper minerals. The recovery of the sulfide minerals in a desulfurization route results in obtaining of reprocessed tailings with a low acid-generating potential. Additionally, the magnetic separation was tested to separate accompanied valuable minerals—complex Mg, Ca, Fe silicates from quartz—to recover them as a by-product and to minimize the storaged volume of reprocessed tailings. Finally, a possible usage of the obtained mineral products is suggested. | Valorisation of Abandoned Low Grade Tailings in Albania for Recovery of Metal Concentrates and Mineral Products | 10.3103/S106782122105014X |
2021-09-01 | Lithium-sulfur battery is one of the most promising batteries, but it suffers from the low conductivity of sulfur and the dissolution/loss of lithium polysulfide. The dissolution/loss of lithium polysulfide is more serious at low rates, because there is enough time for lithium polysulfide to diffuse to the negative electrode, which leads to poorer cycle stability at low rates than at high rates. Here, a network of carbon nanofibers (NCNFs) is prepared by carbonizing the composite nanofibers of polyacrylonitrile and ZIF-8, which can be used to form composite with sulfur. However, due to poor conductivity and large pore size of NCNFs, the composite delivers low specific capacity and shows poor cycle stability. After coating with a layer of PEDOT:PSS, the conductivity and the dissolution/loss of lithium polysulfide are effectively addressed. As a result, the composite electrode with a sulfur loading up to 3.4 mg exhibits a maximum specific capacity of 793 mAh/g at 0.1 C, which remains to be 623 mAh/g even after 200 cycles. The PEDOT:PSS coating effectively improves the low current rate cyclability, which is a challenge for lithium-sulfur batteries. | Improving the low-rate stability of lithium-sulfur battery through the coating of conductive polymer
| 10.1007/s11581-021-04164-0 |
2021-09-01 | The transport system in cochlear hair cells (HCs) is important for their function, and the kinesin family of proteins transports numerous cellular cargos via the microtubule network in the cytoplasm. Here, we found that Klc2 (kinesin light chain 2), the light chain of kinesin-1 that mediates cargo binding and regulates kinesin-1 motility, is essential for cochlear function. We generated mice lacking Klc2, and they suffered from low-frequency hearing loss as early as 1 month of age. We demonstrated that deficiency of Klc2 resulted in abnormal transport of mitochondria and the down-regulation of the GABAA receptor family. In addition, whole-genome sequencing (WGS) of patient showed that KLC2 was related to low-frequency hearing in human. Hence, to explore therapeutic approaches, we developed adeno-associated virus containing the Klc2 wide-type cDNA sequence, and Klc2-null mice delivered virus showed apparent recovery, including decreased ABR threshold and reduced out hair cell (OHC) loss. In summary, we show that the kinesin transport system plays an indispensable and special role in cochlear HC function in mice and human and that mitochondrial localization is essential for HC survival. | Deficiency of Klc2 Induces Low-Frequency Sensorineural Hearing Loss in C57BL/6 J Mice and Human | 10.1007/s12035-021-02422-w |
2021-09-01 | Extraocular motoneurons initiate dynamically different eye movements, including saccades, smooth pursuit and vestibulo-ocular reflexes. These motoneurons subdivide into two main types based on the structure of the neuro-muscular interface: motoneurons of singly-innervated (SIF), and motoneurons of multiply-innervated muscle fibers (MIF). SIF motoneurons are thought to provoke strong and brief/fast muscle contractions, whereas MIF motoneurons initiate prolonged, slow contractions. While relevant for adequate functionality, transmitter and ion channel profiles associated with the morpho-physiological differences between these motoneuron types, have not been elucidated so far. This prompted us to investigate the expression of voltage-gated potassium, sodium and calcium ion channels ( Kv1.1 , Kv3.1b , Nav1.6 , Cav3.1 – 3.3 , KCC2 ), the transmitter profiles of their presynaptic terminals ( vGlut1 and 2 , GlyT2 and GAD ) and transmitter receptors ( GluR2/3 , NMDAR1 , GlyR1α ) using immunohistochemical analyses of abducens and trochlear motoneurons and of abducens internuclear neurons (INTs) in macaque monkeys. The main findings were: (1) MIF and SIF motoneurons express unique voltage-gated ion channel profiles, respectively, likely accounting for differences in intrinsic membrane properties. (2) Presynaptic glutamatergic synapses utilize vGlut2, but not vGlut1. (3) Trochlear motoneurons receive GABAergic inputs, abducens neurons receive both GABAergic and glycinergic inputs. (4) Synaptic densities differ between MIF and SIF motoneurons, with MIF motoneurons receiving fewer terminals. (5) Glutamatergic receptor subtypes differ between MIF and SIF motoneurons. While NMDAR1 is intensely expressed in INTs, MIF motoneurons lack this receptor subtype entirely. The obtained cell-type-specific transmitter and conductance profiles illuminate the structural substrates responsible for differential contributions of neurons in the abducens and trochlear nuclei to eye movements. | Transmitter and ion channel profiles of neurons in the primate abducens and trochlear nuclei | 10.1007/s00429-021-02315-7 |
2021-09-01 | The present investigation focuses on the design and development of low-cost carbon and glass fiber-reinforced polymer hybrid composite with optimum flexural strength and modulus, Charpy impact strength, resistance to low-velocity impact, and abrasive wear. There are three hybrid composites ([C 2 G 8 ], [C 3 G 7 ], and [C 4 G 6 ]) along with a plain glass ([G 10 ]) and carbon ([C 10 ]) fiber-reinforced polymer composites are fabricated using hand lay-up method. The results revealed that [C 2 G 8 ] type hybrid composite possessed optimum flexural strength (394.35 MPa), resistance to low-velocity impact (92.42 J), Charpy impact strength (160 kJ/m 2 ), and minimum specific wear rate (22.87 × 10 –3 mm 3 /Nm) in comparison to other hybrid composites. The damaged area due to low- velocity impact was found to be least for [C 2 G 8 ] type hybrid composite compared to other hybrid composites. Furthermore, fractography analysis was carried out by visual inspection and scanning electron microscopy to make possible structure–property co-relationship. | Improvement of Low-Velocity Impact and Abrasive Wear Resistance of Carbon/Glass Fiber-Reinforced Polymer Hybrid Composites | 10.1007/s12666-021-02318-2 |
2021-09-01 | The potential changes in the strength and location of five low-level jets (LLJs) located within four Coordinated Regional Climate Downscaling Experiment (CORDEX) domains are examined for present and future climate conditions using an ensemble of simulations conducted with the RegCM4 regional model at a 25 km horizontal grid spacing. Lateral and lower boundary forcing fields are from three General Circulation Models (GCMs), and we analyse a historical period (1995–2014) along with two future periods (2041–2060 and 2080–2099) under the Representative Concentration Pathways 2.6 and 8.5. The RegCM4, as driven by the GCMs, is capable of capturing most of the observed climatological features of the LLJs, both in terms of spatial location and seasonal evolution. Analysis of the influence of global warming on the LLJs shows a consistent strengthening of the jets and a shift in their location under both warming scenarios. The Monsoon and West African westerly LLJs exhibit a northward shift, while the Caribbean and South American LLJs present a westward expansion. The use of an ensemble of high-resolution simulations is found to provide a key element for a robust assessment of changes in LLJs associated with future global warming scenarios. | Future projections in the climatology of global low-level jets from CORDEX-CORE simulations | 10.1007/s00382-021-05671-6 |
2021-09-01 | Abstract The system is described for the formation of the low-temperature starting plasma flow in the GOL-NB trap. The starting plasma is a target for capturing heating neutral beams. The plasma flow is formed in the arc plasma gun installed in a relatively weak magnetic field. Next, it is compressed in the increasing magnetic field and then transported to a distance of approximately 4 m. The design of the plasma gun is described. Optimization of the operating regimes and scenarios of the system for creating the starting plasma made it possible to reduce the gas load onto the vacuum system of the facility, which resulted in reducing the losses associated with the presence of gas dragged along together with the plasma. The plasma flow at the outlet from the high magnetic field section is increased approximately four times, as compared to the results of the first plasma campaign. It is discussed how the limiters and other intrachamber electrodes affect the plasma flow formation. The achieved plasma flow parameters will be sufficient to start the experiments on plasma heating with the help of neutral beams at the GOL-NB multi-mirror trap in its full-design configuration. | Formation of Starting Plasma Flow in an Open Trap Using Arc Plasma Gun | 10.1134/S1063780X21090026 |
2021-09-01 | Purpose Adverse effects of iron fortification/supplements such as Micronutrient Powder (MNP) on gut microbiota have previously been found in infection-prone African settings. This study examined the adversaries of a low-iron MNP compared with the standard MNP on the composition of gut microbiota in Bangladeshi children exposed to a high concentration of iron from potable groundwater. Methods A randomized controlled trial was conducted in 2- to 5-year-old children, drinking groundwater with a high concentration of iron (≥ 2 mg/L). Children were randomized to receive one sachet per day of either standard MNP (12.5 mg iron) or low-iron MNP (5 mg iron), for 2 months. A sub-sample of 53 children was considered for paired assessment of the gut microbiome by 16S rRNA amplicon sequencing. Results At baseline, the gut microbiota consisted of Bifidobacteriaceae (15.6%), Prevotellaceae (12.2%), Lactobacillaceae (3.6%), Clostridiaceae (4.1%) and Enterobacteriaceae (2.8%). Overall, there was no significant treatment effect of the low-iron MNP compared to the standard MNP. However, an apparent treatment effect was observed in children with a relative adult-like microbiota, with a higher relative abundance of potentially pathogenic Enterobacteriaceae after receiving the standard MNP compared to the low-iron MNP. This effect, however, was statistically non-significant ( p = 0.07). Conclusion In Bangladeshi children drinking iron-rich groundwater, a low-iron MNP supplementation did not have a significant impact on their gut microbiota profile/composition compared to the standard MNP. The trial registration number is ISRCTN60058115; Date of registration 03/07/2019; retrospectively registered. | Effect of low-iron micronutrient powder (MNP) on the composition of gut microbiota of Bangladeshi children in a high-iron groundwater setting: a randomized controlled trial | 10.1007/s00394-021-02523-1 |
2021-09-01 | Nitrogen is one of the essential elements for plant growth. Wild soybeans ( Glycine soja ) have strong abilities to survive in harsh and barren environments, and hence become ideal plant model for studying plant adaptability to low nitrogen (LN) conditions. In this study, we analyzed and compared the transcriptomes of wild soybean subjected to LN treatments. We totally identified 1095 (681 up and 414 down) and 5490 (2998 up and 2492 down) differentially expressed genes (DEGs) in the aerial parts (leaf and stem, LS) and roots, respectively. Gene ontology classification analysis revealed that the categories related to LN stress (including oxidation reduction, transcriptional regulation, membrane, and protein phosphorylation) were highly enriched among DEGs. In addition, a total of 784 transcription factor (TF) and 84 transporter protein (TP) genes were determined in LS DEGs, of which some TF genes ( NAC1 , NAC35 , ZFP1 , CIM1 , and WRKY25 ) and TP genes like NRT2.5 (nitrate transporter) and ABCC12 (ABC transporter) were widely upregulated under LN stress. Nevertheless, a total of 3859 TF and 370 TP genes were identified in root DEGs, of which some TF genes ( NAC6 , NAC14 , MYB29 , MYB92 , bZIP62 , bZIP72 , WRKY60 , WRKY58 ) and TP genes like NRT2.4 and HAK5 (potassium transporter) were upregulated under LN stress. These findings suggest that the identified DEGs may play vital roles in plant responses to LN stress, providing important genetic resources for further functional dissection of plant molecular mechanisms to LN stress. | Transcriptome sequencing of wild soybean revealed gene expression dynamics under low nitrogen stress | 10.1007/s13353-021-00628-1 |
2021-09-01 | Background A low β superconducting elliptical cavity was designed for the China Spallation Neutron Source phase II project (CSNS-II). Methods The method to improve the mechanical stability of the low β superconducting elliptical cavity was introduced, and the corresponding mechanical design was given. The software COMSOL Multiphysics and ANSYS APDL were used to calculate the static Lorentz force detuning factor k L (LFD) and the helium pressure sensitivity factor k p (DFDP) of the bare cavity, which were − 4.71 Hz (MV/m) −2 and − 21.1 Hz/mbar, respectively. The double-ring stiffeners reinforcement scheme was adopted. Results The radii of the double-ring stiffeners were 70 and 135 mm, respectively. The structure design of the helium vessel of the cavity was given. The following is the mechanical parameters of the reinforced cavity, the tuning sensitivity is 199.8 kHz/mm, longitudinal stiffness is 4.76kN/mm, k L and k p were − 1.39 Hz (MV/m) −2 and 4.67 Hz/mbar, respectively, which met the operating requirements. The tuning sensitivity and stiffness of the reinforced cavity with different wall thicknesses were optimized, and the final wall thickness was selected as 4 mm. Conclusion The mechanical design of CSNS-II 648 MHz five-cell low β superconducting elliptical cavity was introduced systematically in the paper. The LFD, DFDP, and the maximum surface stress of the cavity were reduced by optimizing the cavity wall thickness and the position of the double-ring stiffeners. The reinforced cavity met operational requirements. | Mechanical design of a low β superconducting elliptical cavity for CSNS-II | 10.1007/s41605-021-00260-x |
2021-09-01 | Purpose Obesity has been related to intestinal dysbiosis and the modification of gut microbiota composition by dietary strategies becomes a promising strategy to help manage obesity. The aim of the current study was to evaluate the effect of two weight-loss diets on the composition and functional profile of gut microbiota. Methods 55 men and 124 women with BMI > 25 kg/m 2 were randomly assigned to moderately high-protein (MHP) or low-fat (LF) diet. Differences in fecal bacteria abundance (based on 16 s rRNA sequencing) between before and after 4 months of calorie restriction was analyzed using EdgeR tool in MicrobiomeAnalyst platform. Bacterial functional profile was predicted using Tax4Fun and metagenomeSeq analysis. Significant KEGG Orthology (KO) terms were selected for the metabolomic study using chromatography. Results After the intervention, MHP-men showed a significant decrease in Negativicutes, Selenomonadales, Dielma and Dielma fastidiosa . LF-men showed a significant increase in Bacilli, Lactobacillales, Christensenellaceae, Peptococcaceae, and Streptococcaceae, Peptococcus , Streptococcus and Christensenella, Duncaniella dubosii _CP039396_93.49%, Roseburia sp _AB744234_98.96% and Alistipes inops _KJ572413_99.57%. MHP-women increased Pasteurellales, Phascolarctobacterium succinatutens , Ruthenibacterium lactatiformans _LR215981_99.55% and decreased in Phascolarctobacterium succinatutens _NR112902_99.56%. Finally, LF-women presented a significant decrease in Bacteroides clarus and Erysipelothrix inopinata _CP060715_84.4%. Surprisingly, no matching bacterial changes were found between these four groups. A total of 42 KO, 10 metabolic pathways and 107 related metabolites related were found implicated in these bacterial changes. Seven metabolites were confirmed in plasma. Conclusion Weight-loss-related-changes in gut microbiome composition and the functional profile occur in a sex- and diet-related manner, showing that women and men could differentially benefit from the consumption of MHP and LF diets. Trial registration NCT02737267, 10th March 2016 retrospectively registered. | Diet- and sex-related changes of gut microbiota composition and functional profiles after 4 months of weight loss intervention | 10.1007/s00394-021-02508-0 |
2021-09-01 | Climate change caused by carbon emissions has a strong influence on the economy and human society. Though numerous previous studies have emphasized the importance of low-carbon innovation on curbing or mitigating carbon emissions, not much attention has been given to the reverse effect. We used a panel of 285 Chinese prefecture-level cities from 2005 to 2016 and Cooperative Patent Classification (CPC)-Y02 patents as low-carbon innovation indicators. The results show that the increasing carbon emissions accelerate cities’ low-carbon innovation in China, and the predicted effect varies across low-carbon innovation types. As carbon emissions rise, more low-carbon innovation will occur in activities with higher carbon emissions. Besides, we explore environmental awareness as the mediation channel for carbon emissions to impact low-carbon innovation. With the help of media, government, and enterprises, the growing carbon emissions promote public environmental awareness and change consumers’ behaviors, motivating companies to speed up low-carbon innovation. | Do carbon emissions accelerate low-carbon innovation? Evidence from 285 Chinese prefecture-level cities | 10.1007/s11356-021-14291-w |
2021-09-01 | The article presents the study of Particulate Matter air pollution with PM 1 , PM 2,5 and PM 10 by means of a low-cost sensors mounted on Unmanned Aerial Vehicles. The article is divided into two parts. In first part pollution measurement system is described. In second part expert system for optimization of flight parameters is described. The research was conducted over a municipal cemetery area in Poland. The obtained results were analyzed through an inductive knowledge management system (decision tree method) for classification analysis of air pollution. The decision tree mechanism would be used to optimize flight parameters taking into account the air pollution parameters. The analysis was made from the influence of PM concentration point of view, depending on the altitude. The decision tree method was used, which allowed to determine, among other aspects, which PM indicator should be measured and which altitude plays a greater role in the optimization of air pollution measurements by means of cheap sensors mounted on drones. As a result of the analysis, the optimum flight altitude of the measurement drone in the specified area was determined. | Optimization of air pollution measurements with unmanned aerial vehicle low-cost sensor based on an inductive knowledge management method | 10.1007/s11081-021-09668-2 |
2021-09-01 | Recently, the basal beds of the lower section of the Lumbrera Formation have been referred to the early Eocene (Ypresian) based on the identification of a succession of hyperthermal events globally dated between 52 and 55 Ma. Nevertheless, this section have also been referred to the middle Eocene (Lutetian) based on the ‘evolutionary stage’ of its fossil mammals. In this contribution, we present a new 238 U- 206 Pb isochron age (46.2 Ma) obtained from samples taken on various independent points across paleosol and matrix positioned at the top of the lower section of the Lumbrera Formation. The new age is consistent with the hyperthermal scheme and constrains the deposition of the lower section of the Lumbrera Fm. between 55–46.2 Ma. In this new geochronological framework, we present one of the most ancient cingulate assemblages from America, recorded during the early Eocene hyperthermal. The specimens involved were recovered from the lowest levels of the lower section of the Lumbrera Formation at Los Cardones National Park, Calchaquí Valleys, Salta Province, Argentina. This cingulate assemblage is formed by the armadillos Pucatherium parvum , a species widely distributed in the Eocene of northwestern Argentina and a new taxon, Noatherium emilioi , gen. et sp. nov. In this new geochronological framework, the taxonomic composition and morphological variations observed in the two species described here and their probably contemporaneous Riostegotherium yanei from the Itaboraí basin (Brazil) support an early diversification of the Cingulata during the Paleocene, and reinforce an intertropical origin for the group. | The Early Eocene Climatic Optimum at the Lower Section of the Lumbrera Formation (Ypresian, Salta Province, Northwestern Argentina): Origin and Early Diversification of the Cingulata | 10.1007/s10914-021-09545-w |
2021-09-01 | Urban areas are vulnerable to flooding as a result of climate change and rapid urbanization and thus flood losses are becoming increasingly severe. Low impact development (LID) measures are a storm management technique designed for controlling runoff in urban areas, which is critical for solving urban flood hazard. Therefore, this study developed an exploratory simulation–optimization framework for the spatial arrangement of LID measures. The proposed framework begins by applying a numerical model to simulate hydrological and hydrodynamic processes during a storm event, and the urban flood model coupled with the source tracking method was then used to identify the flood source areas. Next, based on source tracking data, the LID investment in each catchment was determined using the inundation volume contribution ratio of the flood source area (where most of the investment is required) to the flood hazard area (where most of the flooding occurs). Finally, the resiliency and sustainability of different LID scenarios were evaluated using several different storm events in order to provide suggestions for flooding prediction and the decision-making process. The results of this study emphasized the importance of flood source control. Furthermore, to quantitatively evaluate the impact of inundation volume transport between catchments on the effectiveness of LID measures, a regional relevance index ( RI ) was proposed to analyze the spatial connectivity between different regions. The simulation–optimization framework was applied to Haikou City, China, wherein the results indicated that LID measures in a spatial arrangement based on the source tracking method are a robust and resilient solution to flood mitigation. This study demonstrates the novelty of combining the source tracking method and highlights the spatial connectivity between flood source areas and flood hazard areas. | Low Impact Development Measures Spatial Arrangement for Urban Flood Mitigation: An Exploratory Optimal Framework based on Source Tracking | 10.1007/s11269-021-02915-2 |
2021-09-01 | Abstract Measurements in a desertified area in Astrakhan oblast at heights from 3 to 15 cm under almost nonintermittent saltation on August 23 and September 9, 2011, have been used to determine the size distribution functions of saltating particles in the range from 30 to 330 μm and the vertical profiles of differential number concentrations of particles with sizes of 47.0, 85.6, 104.6, 127.7, and 156.0 μm, which are approximated by exponents. In the lower saltation layer of around 9 cm in thickness, the height scale and the logarithmic concentration gradient have been found to be independent of wind speed. At heights of 11 and 15 cm, the total concentration of saltating particles is nonlinearly related to wind speed in the atmospheric surface layer. For the variation range of wind speeds from 6 to 11.0 m/s, vertical distributions of the concentration of saltating particles have been constructed using approximations by piecewise exponential profiles of the total concentration of particles. An analytical dependence of the logarithmic concentration gradient in the upper saltation layer on the wind speed has been obtained. A small-parameter model of the vertical distribution of saltating particles in the range of heights from 0 to 15 cm has been developed. Approximations of dependences of the height scale on the particle size have been proposed for the vertical profiles of concentration and mass fluxes of saltating particles. | Vertical Distribution of Aleurite and Sand Particles in Windsand Flux over a Desertified Area | 10.1134/S0001433821050078 |
2021-09-01 | The severe acute respiratory syndrome coronavirus 2 pandemic has had disproportionate effects on economically and socially marginalized people. We explore the effects on low-wage migrant workers (migrant workers) in three countries: Singapore, South Korea and Brazil, through the lens of the social determinants of health. Our analysis shows that governments missed key opportunities to mitigate pandemic risks for migrant workers. Government measures demonstrate potential for effective and sustainable policy reform, including universal and equitable access to healthcare, social safety nets and labour rights for migrant workers—key concerns of the Global Compact for Migration. A whole-of-society and a whole-of-government approach with Health in All Policies, and migrant worker frameworks developed by the World Health Organization could be instrumental. The current situation indicates a need to frame public health crisis responses and policies in ways that recognize social determinants as fundamental to health. | Low-wage migrant workers during coronavirus disease 2019: a social determinants analysis | 10.1057/s41271-021-00303-z |
2021-09-01 | Purpose of review Currently, a lack of guidelines exists regarding best practices for occupational therapists (OTs) in the treatment and evaluation of oculomotor dysfunction following traumatic brain injury (TBI). Furthermore, individuals with TBI would benefit significantly from collaboration between OTs and optometrists during inpatient rehab. Recent findings Although few articles examine interdisciplinary models of inpatient rehab care that include optometry, a recent pilot study is explored. Emerging evidence from the field of optometry supports the use of restorative approaches for oculomotor impairment in mild TBI; however, cases with moderate to severe TBI are not addressed. Summary We describe an interdisciplinary approach involving collaboration between optometry and occupational therapy, yielding a comprehensive model to effectively evaluate and treat oculomotor impairments in those with TBI and facilitate improved performance in daily activities. We also provide guidelines useful for OTs working in settings where collaboration with optometry is not feasible. | Clinical Practice Guidelines for Occupational Therapists in the Evaluation and Treatment of Oculomotor Impairment Following Traumatic Brain Injury | 10.1007/s40141-021-00310-x |
2021-09-01 | Accurate, cost-effective monitoring and management of young forests is important for future stand quality. There is a critical need for a rapid assessment tool for forest monitoring and management. This study uses a low-cost unmanned aerial vehicle (UAV) to complete a tree height and tree density assessment in a newly forested Chinese fir ( Cunninghamia lanceolata (Lamb) Hook) planting (15 sample plots), Shunchang County, Fujian, China (1.12 ha). Images obtained from a Phantom4-Multispectral UAV were used to generate a digital surface model (DSM) with DJI Terra software (0.02 m spatial resolution). Based on the DSM, the individual trees were identified and the height of each corresponding tree was determined. The impacts of factors related to individual tree detection (ITD) and tree height accuracy were also analyzed. For the tree-level, the highest accuracy of ITD for Chinese fir was 98.93% ( F -score = 98.93%). Remotely sensed individual tree heights produced an R 2 value of 0.89, RMSE value of 0.22 m when compared to a field survey. At the stand-level, tree height assessment yielded R 2 = 0.95, RMSE = 0.12 m, and tree density assessment yielded R 2 = 0.99, RMSE = 48 tree ha −1 . The results highlight that UAVs can successfully monitor forest parameters and hold great potential as a supplement or substitute tool in field inventory. | Assessing tree height and density of a young forest using a consumer unmanned aerial vehicle (UAV) | 10.1007/s11056-020-09827-w |
2021-09-01 | Objective To study the predictive effect on YCH patients complicated with LEDVT by PLR and DFR combined with WELLS score. Materials and methods A total of 109 patients with YCH were selected as the research subjects. Patients with combined LEDVT were in the thrombosis group (33 cases), and without LEDVT in the non-thrombosis group (76 cases). Wells score was used to evaluate the vascular of the lower extremities. The PLR and DFR were calculated. The diagnostic value of PLR and DFR combined with the Wells score was evaluated by the AUC, sensitivity, specificity, and other indicators in the ROC. Results The values of PLR, DFR, and Wells score in the thrombus group were 149.20 ± 52.17, 118.46 ± 8.37, and 2.67 ± 0.48, and that of the non-thrombotic group were 95.27 ± 29.48, 75.28 ± 10.16, and 0.72 ± 0.34, respectively. The differences were statistically significant. ROC results showed good diagnosis power of PLR (sensitivity 86.35%, specificity 75.18%, AUC 0.702.), DFR (sensitivity 88.57%, specificity 79.21%, AUC 0.786.), and the Wells score (sensitivity 90.17%, specificity 81.06%, AUC 0.889.). The combined application of the Wells score, PLR, and DFR for the occurrence of LEDVT had a sensitivity of 97.65%, a specificity of 92.43%, a missed diagnosis rate of 2.35%, and a misdiagnosis rate of 7.57%. The area under the ROC curve was 0.951, which was higher than using these variables independently. Conclusions PLR and DFR combined with Wells score have high specificity for predicting LEDVT in YCH patients with low missed diagnosis and low misdiagnosis rates. They are worthy of popularization and application. | The predictive value of platelet to lymphocyte ratio and D-dimer to fibrinogen ratio combined with WELLS score on lower extremity deep vein thrombosis in young patients with cerebral hemorrhage | 10.1007/s10072-020-05007-y |
2021-08-29 | Background Lumbopelvic control (LPC) has recently been associated with function, kinesiology, and load distribution on the limb. However, poor LPC has not been studied as a risk factor for lower limb injury in sports requiring frequent jump landings. The present study investigated the effects of LPC on landing mechanics and lower limb muscle activity in professional athletes engaged in sport requiring frequent landing. Methods This study was conducted on 34 professional female athletes aged 18.29 ± 3.29 years with the height and body mass of 173.5 ± 7.23 cm and 66.79 ± 13.37 kg, respectively. The landing error scoring system (LESS) and ImageJ software were used to assess landing mechanics. Wireless electromyography was also used to record the activity of the gluteus medius (GMed), rectus femoris, and semitendinosus. Lumbopelvic control was evaluated using the knee lift abdominal test, bent knee fall-out, active straight leg raising, and the PRONE test using a pressure biofeedback unit. Based on the LPC tests results, the participants were divided into two groups of proper LPC (n = 17) and poor LPC (n = 17). Results There were significant differences between the groups with proper and poor LPC in terms of the LESS test scores ( P = 0.0001), lateral trunk flexion ( P = 0.0001), knee abduction ( P = 0.0001), knee flexion ( P = 0.001), trunk flexion ( P = 0.01), and GMed muscle activity ( P = 0.03). There were no significant differences in the activity of the rectus femoris and semitendinosus muscles, and ankle dorsiflexion ( P > 0.05). Conclusions Poor lumbopelvic control affects the kinematics and activity of the lower limb muscles, and may be a risk factor for lower limb injuries, especially of the knee. | Effect of lumbopelvic control on landing mechanics and lower extremity muscles’ activities in female professional athletes: implications for injury prevention | 10.1186/s13102-021-00331-y |
2021-08-28 | Effect of low temperature and low oxygen concentration on biochemical attributes, antioxidant enzyme activities, phenolics profile and expression of phenylpropanoid pathway-related genes was investigated in crabapple ( Malus profusion ) fruit. Crabapple fruit were kept at room temperature (RT, 20 ± 2 °C and 25 ± 2 °C alternatively at 12 h cycle) or low temperature (LT, 10 ± 2 °C and 25 ± 2 °C alternatively at 12 h cycle) and supplemented with either normal oxygen (21%) or low oxygen levels (5%) for 9 days. Results revealed higher concentrations of soluble solids, titratable acids, and ascorbic acid in fruit stored at LT + 5% O 2 . Likewise, total phenolics, peroxidase activity, and 2,2´-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)-radical scavenging activity were observed to be significantly higher in fruit stored at low temperature (LT + 5% O 2 > LT + 21% O 2 ), followed by those stored at room temperature (RT + 5% O 2 > RT + 21% O 2 ). In contrast, H 2 O 2 and malondialdehyde contents were significantly enhanced in fruit stored at room temperature (RT + 21% O 2 and RT + 5% O 2 ), whereas fruit stored at low temperature showed minimum inhibition in superoxide dismutase, catalase and ascorbate peroxidase activities. In addition, low temperature induced biosynthesis of phenolic acids, whereas no considerable changes were observed in flavanols and dihydrochalcones during storage. Low temperature and oxygen conditions (LT + 5% O 2 ) significantly enhanced the biosynthesis of flavonols (glycosylated quercetin derivatives) and cyanidin 3-galactoside, compared to LT + 21% O 2 , RT + 5% O 2 and RT + 21% O 2 conditions. In addition, low temperature also up-regulated the expression of MpFLS and MpUFGT in fruit tissues. Moreover, correlation analysis suggested positive association of antioxidant capacity with the biosynthesis of flavonols and anthocyanins in fruit stored at LT + 5% O 2 . | Low temperature and hypoxic conditions induce flavonoids biosynthesis and enhances antioxidant potential of crabapple (Malus profusion) fruits | 10.1007/s11738-021-03302-5 |
2021-08-26 | Due to the global rise of the human population, one of the top-most challenges for poor and developing nations is to use the food produces safely and sustainably. In this regard, the storage of surplus food (and derived products) without loss of freshness, nutrient stability, shelf life, and their parallel efficient utilization will surely boost the food production sector. One of the best technologies that have emerged within the last twenty years with applications in the packaging of food and industrial materials is the use of green mode-based synthesized nanoparticles (NPs). These NPs are stable, advantageous as well as eco-friendly. Over the several years, numerous publications have confirmed that these NPs exert antibacterial, antioxidant, and antifungal activity against a plethora of pathogens. The storage in metal-based NPs (M-NPs) does not hamper the food properties and packaging efficiency. Additionally, these M-NPs help in the improvement of properties including freshness indicators, mechanical properties, antibacterial and water vapor permeability during food packaging. As a result, the nano-technological application facilitates a simple, alternate, interactive as well as reliable technology. It even provides positive feedback to food industries and packaging markets. Taken together, the current review paper is an attempt to highlight the M-NPs for prominent applications of antimicrobial properties, nanosensors, and food packaging of food items. Additionally, some comparative reports associated with M-NPs mechanism of action, risks, toxicity, and overall future perspectives have also been made. | Metal-based nanoparticles, sensors, and their multifaceted application in food packaging | 10.1186/s12951-021-00996-0 |
2021-08-26 | Background For over a decade, antiretroviral therapy (ART) in resource-limited countries was only recommended for patients with advanced HIV disease. We investigated this group of patients in order to determine any relationship between degree of immunosuppression during treatment initiation and the subsequent levels of inflammatory biomarkers, reservoir size and plasma marker of fungal translocation after achieving long-term virological control. Methods We analyzed 115 virally suppressed (female 83.5%) and 40 untreated (female 70%) subjects from Dar es Salaam, Tanzania. The size of HIV latent reservoir (proviral DNA copy) was determined using quantitative PCR. Inflammatory biomarkers; IL-6, IL-10, and soluble CD14 (sCD14), were measured using multiplex cytometric beads array. Antibody titers for Cytomegalovirus (CMV) and Epstein Barr virus (EBV), plasma level of 1-3-beta- d -Glucan (BDG) was measured using ELISA. High-sensitivity C-reactive protein (hsCRP) was measured using nephelometric method. Results The median age was 36 (IQR 32-44) and 47 (IQR 43–54) years in untreated and virally suppressed patients respectively. Median duration of treatment for virally suppressed patients was 9 years (IQR 7–12) and median baseline CD4 count was 147 cells/mm 3 (IQR 65–217). Virally suppressed patients were associated with significantly lower plasma levels of IL-10, sCD14 and BDG (P < 0.05) when compared to untreated patients. However, plasma level of IL-6 was similar between the groups. Baseline advanced level of immunosuppression (CD4 < 100cells/cm 3 ) was associated with significantly higher plasma level of IL-6 ( P = 0.02), hsCRP ( P = 0.036) and BDG ( P = 0.0107). This relationship was not seen in plasma levels of other tested markers. Degree of baseline immunosuppression was not associated with the subsequent proviral DNA copy. In addition, plasma levels of inflammatory marker were not associated with sex, CMV or EBV antibody titers, treatment duration or regimen. Conclusions Our data suggest that advanced immunosuppression at ART initiation is associated with severity of inflammation and elevated fungal translocation marker despite long term virological control. Further studies are needed to evaluate the potential increased burden of non-AIDS comorbidities that are linked to elevated inflammatory and fungal translocation markers as a result of the policy of HIV treatment at CD4 count < 200 cells/cm 3 implemented for over a decade in Tanzania. | Advanced baseline immunosuppression is associated with elevated levels of plasma markers of fungal translocation and inflammation in long-term treated HIV-infected Tanzanians | 10.1186/s12981-021-00381-9 |
2021-08-26 | Background Immunization directly impacts health (SDG3) and brings a contribution to 14 out of the 17 Sustainable Development Goals (SDGs), such as ending poverty, reducing hunger, and reducing inequalities. Therefore, immunization is recognized to play a central role in reaching the SDGs, especially in low- and middle-income countries (LMICs). Despite continuous interventions to strengthen immunization systems and to adequately respond to emergency immunization during epidemics, the immunization-related indicators for SDG3 lag behind in sub-Saharan Africa. Especially taking into account the current Covid19 pandemic, the current performance on the connected SDGs is both a cause and a result of this. Methods We conduct a literature review through a keyword search strategy complemented with handpicking and snowballing from earlier reviews. After title and abstract screening, we conducted a qualitative analysis of key insights and categorized them according to showing the impact of immunization on SDGs, sustainability challenges, and model-based solutions to these challenges. Results We reveal the leveraging mechanisms triggered by immunization and position them vis-à-vis the SDGs, within the framework of Public Health and Planetary Health. Several challenges for sustainable control of vaccine-preventable diseases are identified: access to immunization services, global vaccine availability to LMICs, context-dependent vaccine effectiveness, safe and affordable vaccines, local/regional vaccine production, public-private partnerships, and immunization capacity/capability building. Model-based approaches that support SDG-promoting interventions concerning immunization systems are analyzed in light of the strategic priorities of the Immunization Agenda 2030. Conclusions In general terms, it can be concluded that relevant future research requires (i) design for system resilience, (ii) transdisciplinary modeling, (iii) connecting interventions in immunization with SDG outcomes, (iv) designing interventions and their implementation simultaneously, (v) offering tailored solutions, and (vi) model coordination and integration of services and partnerships. The research and health community is called upon to join forces to activate existing knowledge, generate new insights and develop decision-supporting tools for Low-and Middle-Income Countries’ health authorities and communities to leverage immunization in its transformational role toward successfully meeting the SDGs in 2030. | Advancing sustainable development goals through immunization: a literature review | 10.1186/s12992-021-00745-w |
2021-08-26 | Abstract Background Static or motion manual palpation of the low back is commonly used to assess pain location and reproduction in low back pain (LBP) patients. The purpose of this study is to review the reliability and validity of manual palpation used for the assessment of LBP in adults. Method We systematically searched five databases from 2000 to 2019. We critically appraised internal validity of studies using QAREL and QUADAS-2 instruments. We stratified results using best-evidence synthesis. Validity studies were classified according to Sackett and Haynes. Results We identified 2023 eligible articles, of which 14 were low risk of bias. Evidence suggests that reliability of soft tissue structures palpation is inconsistent, and reliability of bony structures and joint mobility palpation is poor. We found preliminary evidence that gluteal muscle palpation for tenderness may be valid in differentiating LBP patients with and without radiculopathy. Conclusion Reliability of manual palpation tests in the assessment of LBP patients varies greatly. This is problematic because these tests are commonly used by manual therapists and clinicians. Little is known about the validity of these tests; therefore, their clinical utility is uncertain. High quality validity studies are needed to inform the clinical use of manual palpation tests. | Reliability and validity of manual palpation for the assessment of patients with low back pain: a systematic and critical review | 10.1186/s12998-021-00384-3 |
2021-08-25 | The omnipresence of oysters in Cenozoic sedimentary series and their high preservation potential allowed their consideration as one of the ecological indicators for the reconstitution of the palaeoenvironments of the Neogene basins of Orania. Few researches were interested in the systematics of Messinian oysters of the Lower Chelif and Tafna basins (Freneix et al. 1988 ), whereas this work is the first to specify the Tortonian-Messinian oyster environments in the three Neogene basins (Lower Chelif, Tafna, M’sirda). This study was made on the basis of shell material collected from eight sections. Only shells with autochthonous character are taken into consideration for the interpretation of paleoenvironments, which is based on several references (Videt et Neraudeau, 2002 ; Freneix et al. 1988 ; Satour 2012 ; Satour et al. 2020 ). Four oysters have been identified ( Neopycnodonte navicularis , Hyotissa hyotis , Crassostrea gryphoides and Ostrea lamellosa offreti ), and they are included in ten oyster levels, belonging to three time intervals (C5n, C4r-C4n and C3Ar-C3An). The palaeoenvironmental distribution analysis of late Miocene oyster allowed to define a warm subtropical to cool climate for the late Tortonian stage, which becomes warm again (temperature 16–18 °C) in the Messinian. | Palaeoenvironmental distribution of late Miocene oysters in the northwestern Algerian basins | 10.1007/s12517-021-08248-z |
2021-08-23 | Background The identification and functional analysis of genes that improve tolerance to low potassium stress in S. spontaneum is crucial for breeding sugarcane cultivars with efficient potassium utilization. Calcineurin B-like (CBL) protein is a calcium sensor that interacts with specific CBL-interacting protein kinases (CIPKs) upon plants’ exposure to various abiotic stresses. Results In this study, nine CBL genes were identified from S. spontaneum . Phylogenetic analysis of 113 CBLs from 13 representative plants showed gene expansion and strong purifying selection in the CBL family. Analysis of CBL expression patterns revealed that SsCBL01 was the most commonly expressed gene in various tissues at different developmental stages. Expression analysis of SsCBLs under low K + stress indicated that potassium deficiency moderately altered the transcription of SsCBLs . Subcellular localization showed that SsCBL01 is a plasma membrane protein and heterologous expression in yeast suggested that, while SsCBL01 alone could not absorb K + , it positively regulated K + absorption mediated by the potassium transporter SsHAK1. Conclusions This study provided insights into the evolution of the CBL gene family and preliminarily demonstrated that the plasma membrane protein SsCBL01 was involved in the response to low K + stress in S. spontaneum . | Comparative phylogenetic analysis of CBL reveals the gene family evolution and functional divergence in Saccharum spontaneum | 10.1186/s12870-021-03175-3 |
2021-08-21 | Background Gene electrotransfer is an established method that enables transfer of DNA into cells with electric pulses. Several studies analyzed and optimized different parameters of gene electrotransfer, however, one of main obstacles toward efficient electrotransfection in vivo is relatively poor DNA mobility in tissues. Our aim was to analyze the effect of impaired mobility on gene electrotransfer efficiency experimentally and theoretically. We applied electric pulses with different durations on plated cells, cells grown on collagen layer and cells embedded in collagen gel (3D model) and analyzed gene electrotransfer efficiency. In order to analyze the effect of impaired mobility on gene electrotransfer efficiency, we applied electric pulses with different durations on plated cells, cells grown on collagen layer and cells embedded in collagen gel (3D model) and analyzed gene electrotransfer efficiency. Results We obtained the highest transfection in plated cells, while transfection efficiency of embedded cells in 3D model was lowest, similarly as in in vivo. To further analyze DNA diffusion in 3D model, we applied DNA on top or injected it into 3D model and showed, that for the former gene electrotransfer efficiency was similarly as in in vivo. The experimental results are explained with theoretical analysis of DNA diffusion and electromobility. Conclusion We show, empirically and theoretically that DNA has impaired electromobility and especially diffusion in collagen environment, where the latter crucially limits electrotransfection. Our model enables optimization of gene electrotransfer in in vitro conditions. | The impact of impaired DNA mobility on gene electrotransfer efficiency: analysis in 3D model | 10.1186/s12938-021-00922-3 |
2021-08-21 | In this paper, a wide-range current mirror based on a low-power flipped voltage follower with improved performance parameters is proposed. In the proposed design the flipped voltage follower cell uses a MOS transistor in its feedback path, due to which the output impedance gets scaled down, which when applied for current mirror realization shows very low input resistance of about 48 ohms. The other improvement achieved is in terms of output resistance, for which the cascode approach has been utilized. The output resistance achieved is 3G ohms. The proposed current mirror operates with minimal error till 1 mA and exhibits very less input compliance voltage. The –3 dB bandwidth is about 890 MHz. The process corner, temperature analysis and Monte Carlo runs for the proposed design are also shown. The complete analysis is done using Spice on 0.18-um technology at a supply voltage of $$\pm$$ ± 0.5 V. | Low-voltage wide-range high-impedance flipped voltage follower current mirror | 10.1007/s12046-021-01694-1 |
2021-08-18 | Peatlands are responsible for the majority of methane (CH 4 ) emission from wetlands globally. Hydrological changes induced by climatic and anthropogenic disturbance may substantially alter CH 4 emission in peatlands. Here we measured CH 4 emission monthly for 1.5 years in natural, drained and restored shrub bogs in North Carolina, USA. Methane emissions from all sites were consistently low (< 0.05 mg CH 4 m − 2 h − 1 ). We occasionally detected markedly higher CH 4 emissions (> 1 mg CH 4 m − 2 h − 1 ) at sites where the water level remained close to the ground surface for 2–3 months, suggesting that surface litter mostly, not deep peat, contributes to CH 4 emission. We verified this inference by incubating 2-cm sections of peat sliced from intact soil cores for 6 months. Only the saturated surface litter emitted CH 4 , which indicated a 5-cm threshold of ground water level for CH 4 emission in our shrub bogs. During a wet year, water levels in the wet sites (natural and restored) remained at least 5 cm below soil surface for about 90 % of the days. We thus demonstrate the CH 4 emission is negligible from these shrub bogs. This study also indicates that restoration through a non-inundated rewetting would not stimulate CH 4 emission in drained/degraded low-latitude shrub bogs, such as pocosins. | The Effects of Hydrological Management on Methane Emissions from Southeastern Shrub Bogs of the USA | 10.1007/s13157-021-01486-7 |
2021-08-16 | To study the effect of magma intrusion on the thermal evolution of low-rank coal with high moisture content, the relationship between moisture content variation and thermal conductivity of low-rank coal was analyzed by COMSOL Multiphysics numerical simulation and field validation. Taking Daxing Mine in Tiefa coalfield as the research background, the effects of magma finite time intrusion mechanism and moisture volatilization in coal on thermal evolution and organic maturity of coal seam are investigated in this paper. The results show that as the sill thickness increases, the thermal evolution temperature of the coal seam increases, the required thermal evolution time increases and the final retention temperature increases after the coal seam is cooled down. The closer coal seam is to magma, the higher maximum temperature it can reach and the longer duration of the maximum temperature. The increase of moisture content of coal makes the thermal conductivity increase, and the rate of heat transfer from coal seam is accelerated, and more heat is transferred to distant places in the same time. At the same time, the heat lost by the magma in the same time increases, the time required for the cooling of the magma decreases, and the maximum temperature reached by the underlying coal seam is significantly lower. The presence of coal moisture weakens the thermal evolution of magma to coal seam and reduces the expected maturity of the coal. The results of average random vitrinite reflectance ( R o ) and moisture examination of coal samples collected at the Daxing Mine site verified the numerical simulation results of magma thermal evolution. | Numerical simulation of magma intrusion on the thermal evolution of low-rank coal | 10.1007/s12665-021-09871-5 |
2021-08-16 | Low impact development (LID) practices are able to mitigate the detrimental effects of urbanization and climate change due to their salient design features. LID can restore the hydrology of urban areas to the pre-development functions by using distributed stormwater control and natural hydrological features. LID can help to achieve the goal of sustainable development as it promotes effective urban stormwater management. This review covers a comprehensive list of LID practices, namely bioretention cell, green roof, infiltration trench, permeable pavement, rain barrel or cistern, rooftop disconnection and vegetative swale. For each type of the LID, the recent advances covering the aspects of principles, design, performance, advantages and disadvantages and costs are systematically reviewed. Additionally, although LID has been quite broadly applied and demonstrated success in urban stormwater management in many countries, there are still some main challenges during the implementation such as clogging and water quality. Meanwhile, this review also highlights the great opportunities for further developments for LID practices to realize their wider practical application. Finally, future research directions are provided in order to give critical insights into potential future works to advance this field of research. | Low Impact Development (LID) Practices: A Review on Recent Developments, Challenges and Prospects | 10.1007/s11270-021-05262-5 |
2021-08-16 | Large-amplitude geomagnetically induced currents (GICs) are the natural consequences of the solar–terrestrial connection triggered by solar eruptions. The threat of severe damage of power grids due to the GICs is a major concern, in particular, at high latitudes, but is not well understood as for low-latitude power grids. The purpose of this study is to evaluate the lower limit of the GICs that could flow in the Japanese power grid against a Carrington-class severe magnetic storm. On the basis of the geomagnetic disturbances (GMDs) observed at Colaba, India, during the Carrington event in 1859, we calculated the geoelectric disturbances (GEDs) by a convolution theory, and calculated GICs flowing through transformers at 3 substations in the Japanese extra-high-voltage (500-kV) power grid by a linear combination of the GEDs. The estimated GEDs could reach ~ 2.5 V/km at Kakioka, and the GICs could reach, at least, 89 ± 30 A near the storm maximum. These values are several times larger than those estimated for the 13–14 March 1989 storm (in which power blackout occurred in Canada), and the 29–31 October 2003 storm (in which power blackout occurred in Sweden). The GICs estimated here are the lower limits, and there is a probability of stronger GICs at other substations. The method introduced here will be immediately applicable for benchmark evaluation of low-latitude GICs against the Carrington-class magnetic storms if one assumes electrical parameters, such as resistance of transmission lines, with sufficient accuracy. | Prediction of geomagnetically induced currents (GICs) flowing in Japanese power grid for Carrington-class magnetic storms | 10.1186/s40623-021-01493-2 |
2021-08-16 | The complex pore network in gas shale may result in the inaccurate evaluation of petro-physical properties with the different models. Therefore, in the current research, we proposed a new methodology of ∆ log R separation method that can be used to distinguish the mature source zone and reservoir zone. When this technique is used together with Thomas Bowman cross-plot, it signifies shaly resource in the study area. The different mature source rock units were recognized based on resistivity log and sonic log by new techniques of models. In the study area, the Goru Formation is marked as source rock, and it is separated by two intervals B and C which shows signs of maturity or reservoir shale. The potential and probable maturity of Lower Goru Formation shale is identified by using the ΔLogR and also the cross-plot techniques of modified ΔLogR. The result shows that the B-interval shale indicates high probable maturity as compared to the C-interval shale. Petro-elastic analysis shows good potential shale gas zone in the B-interval shale as compared to C-interval shale based on other parameters high Young’s modulus, low Poisson’s ratio, high brittleness index, and high total organic carbon content. To check the result acquired from these models, TOC and R˳ were calculated by using well log data. The result obtained from these models indicated that the source rocks encountered in the studied wells having TOC exceeded the kerogen type II for the generation of hydrocarbon and R˳ calculated shows that the source is compensated wet gas in the area. Additional confirmation takes place based on petro-physical properties, i.e., brittleness, so the high brittleness indicates the high rate of hydraulic fracturation. | Petro-physical evaluation and identifying possible resource plays using the porosity and resistivity logs, Lower Indus Basin, Pakistan | 10.1007/s12517-021-08197-7 |
2021-08-12 | Positive Energy Block (PEB) is an emerging paradigm to transform cities into low carbon cities. It is expected that buildings will become the main components of the future energy infrastructure. This scenario demands a structural integration of the cyclical environmental variables in designing our buildings and cities as a whole. However, such an integration continue to be rare due to the dominance of object-oriented approaches. This study contributes to reducing these difficulties by developing a process-oriented approach, focusing on the wind contribution. The assumption posed herein is that the transition towards PEBs should be an opportunity to redefine the rules to organise the built environment structure integrating energy and urban environmental qualities. A case study, involving three public school buildings located in three different urban patterns in Rome, illustrates a preliminary step in developing an integrated platform to orient strategic design solutions towards PEBs. This is done by developing and assessing three indexes: wind form index, wind thermal-loss index, and wind energy production index. The results point out the usability and limits concerning the approach adopted, stressing the relevance of an integrated platform to support decision-makers in planning the agenda to transform buildings as components of PEBs. | Developing a process-oriented approach towards Positive Energy Blocks: the wind-analysis contribution | 10.1186/s40410-021-00141-2 |
2021-08-11 | Background Kiwifruit ( Actinidia Lindl.) is considered an important fruit species worldwide. Due to its temperate origin, this species is highly vulnerable to freezing injury while under low-temperature stress. To obtain further knowledge of the mechanism underlying freezing tolerance, we carried out a hybrid transcriptome analysis of two A. arguta ( Actinidi arguta ) genotypes, KL and RB, whose freezing tolerance is high and low, respectively. Both genotypes were subjected to − 25 °C for 0 h, 1 h, and 4 h. Results SMRT (single-molecule real-time) RNA-seq data were assembled using the de novo method, producing 24,306 unigenes with an N50 value of 1834 bp. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of DEGs showed that they were involved in the ‘starch and sucrose metabolism’, the ‘mitogen-activated protein kinase (MAPK) signaling pathway’, the ‘phosphatidylinositol signaling system’, the ‘inositol phosphate metabolism’, and the ‘plant hormone signal transduction’. In particular, for ‘starch and sucrose metabolism’, we identified 3 key genes involved in cellulose degradation, trehalose synthesis, and starch degradation processes. Moreover, the activities of beta-GC (beta-glucosidase), TPS (trehalose-6-phosphate synthase), and BAM (beta-amylase), encoded by the abovementioned 3 key genes, were enhanced by cold stress. Three transcription factors (TFs) belonging to the AP2/ERF, bHLH (basic helix-loop-helix), and MYB families were involved in the low-temperature response. Furthermore, weighted gene coexpression network analysis (WGCNA) indicated that beta-GC , TPS5 , and BAM3.1 were the key genes involved in the cold response and were highly coexpressed together with the CBF3 , MYC2 , and MYB44 genes. Conclusions Cold stress led various changes in kiwifruit, the ‘phosphatidylinositol signaling system’, ‘inositol phosphate metabolism’, ‘MAPK signaling pathway’, ‘plant hormone signal transduction’, and ‘starch and sucrose metabolism’ processes were significantly affected by low temperature. Moreover, starch and sucrose metabolism may be the key pathway for tolerant kiwifruit to resist low temperature damages. These results increase our understanding of the complex mechanisms involved in the freezing tolerance of kiwifruit under cold stress and reveal a series of candidate genes for use in breeding new cultivars with enhanced freezing tolerance. | Full-length transcriptome profiling reveals insight into the cold response of two kiwifruit genotypes (A. arguta) with contrasting freezing tolerances | 10.1186/s12870-021-03152-w |
2021-08-09 | BaSO 4 waste powder containing radionuclides generated from nuclear facilities must be immobilized into a stable waste form for final disposal. In this study, the immobilization of BaSO 4 waste powder containing simulant radioactive cobalt by low-temperature sintering was evaluated. A simulated decontamination waste was prepared as a BaSO 4 waste powder containing simulant radioactive cobalt, and Bi 2 O 3 -B 2 O 3 -ZnO-SiO 2 glass was used as a binding material for the immobilization. The simulated waste was immobilized into a monolithic waste form at 550 °C without the SO 2 gas generation. The glass was converted into crystal structures during the immobilization. The waste form had a high bulk density (5.05 g/cm 3 ), and it showed a good compressive strength (21.92 MPa). It was also confirmed that the waste form had a high chemical durability through a semi-dynamic leaching test. In particular, the average leaching index of Co was 13.18. These results show that the immobilization has a potential application to BaSO 4 waste powder containing radionuclides for final disposal. | Feasibility Study on Immobilization of Radioactive Cobalt and BaSO4 Waste Powder Using Low-Temperature Sintering | 10.1007/s11270-021-05292-z |
2021-08-09 | Dolomite diagenesis is a key issue in the evolution of dolomite reservoirs. Hence, lower Paleozoic carbonate samples from the Bonan Low Uplift are analyzed. Data collected from thin sections, cathodoluminescence, X-ray diffraction, major and trace elements, rare earth elements, isotopes, and other experimental work to determine the types, diagenetic environment, and fluid characteristics of dolomite, are used to determine its genesis. Three main dolomite types are identified: D1 with a very good original structure, D2 without an original structure, and D3 with a poorly preserved original structure. The concentrations of many geochemical indicators follow the order of D1>D2>D3. The ratios of MnO to TiO 2 in both D2 and D3 are >0.5, and the Rb concentration of D2 is greater than that of D3. δCe shows that D1 and D2 are partially oxidized, while D3 is not. The D1, D2, and D3 diagenetic temperatures are 49.28, 54.96, and 50.23°C, respectively. The order degrees of D1 and D2 are 0.56 and 0.75, respectively, while that of D3 ranges widely. Comprehensive data show that D1 originated from evaporative dolomitization in the syndiagenetic period, and the diagenetic fluid was sea-sourced fluid mixed with terrestrial fluids. D2 was generated by seepage reflux dolomitization, which occurred in the penecontemporaneous-shallow burial period, and its high-salinity diagenetic fluid is inherited from sea-sourced fluids, with the participation of pore fluids. D3 was formed in shallow burial dolomitization, and its diagenetic fluid inherited from sea-sourced fluids and pore fluids is characterized by low salinity. | Geochemical characteristics and genesis of lower Paleozoic dolomites in the central Bohai Sea | 10.1007/s12517-021-08145-5 |
2021-08-09 | Residual plastic deformation induced in low-carbon steels usually demonstrates anisotropy. Eddy current method is applicable for the residual plastic deformation evaluation. However, it is difficult to efficiently evaluate both the principal strain direction and magnitude of residual plastic deformation with the conventional eddy current method. To solve these limitations, a novel method of oscillatory rotating eddy current (OREC) was developed and successfully applied in characterizing the anisotropy of residual plastic deformation in low-carbon steels. The parameters of eddy current response obtained under different frequencies were extracted to characterize the plastic deformation and then the characterization performances of extracted parameters were compared. The compound voltage signal and real part of the impedance could better characterize the residual plastic deformation than the imaginary part of the impedance. It was found that the angle of the major axis of the selected 8-shaped patterns measured with OREC was a good indicator of the principal strain direction. As the residual plastic deformation was increased, the length of the major axis of the 8-shaped patterns monotonously increased despite its sensitivity to the plastic deformation was frequency-dependent. | Evaluation of the Residual Plastic Deformation in Low-Carbon Steel with the Oscillatory Rotating Eddy Current Method | 10.1007/s10921-021-00800-x |
2021-08-07 | Background Priming of seed prior chilling is regarded as one of the methods to promote seeds germination, whole plant growth, and yield components. The application of biostimulants was reported as beneficial for protecting many plants from biotic or abiotic stresses. Their value was as important to be involved in improving the growth parameters of plants. Also, they were practiced in the regulation of various metabolic pathways to enhance acclimation and tolerance in coriander against chilling stress. To our knowledge, little is deciphered about the molecular mechanisms underpinning the ameliorative impact of biostimulants in the context of understanding the link and overlap between improved morphological characters, induced metabolic processes, and upregulated gene expression. In this study, the ameliorative effect(s) of potassium silicate, HA, and gamma radiation on acclimation of coriander to tolerate chilling stress was evaluated by integrating the data of growth, yield, physiological and molecular aspects. Results Plant growth, yield components, and metabolic activities were generally diminished in chilling-stressed coriander plants. On the other hand, levels of ABA and soluble sugars were increased. Alleviation treatment by humic acid, followed by silicate and gamma irradiation, has notably promoted plant growth parameters and yield components in chilling-stressed coriander plants. This improvement was concomitant with a significant increase in phytohormones, photosynthetic pigments, carbohydrate contents, antioxidants defense system, and induction of large subunit of RuBisCO enzyme production. The assembly of Toc complex subunits was maintained, and even their expression was stimulated (especially Toc75 and Toc 34) upon alleviation of the chilling stress by applied biostimulators. Collectively, humic acid was the best the element to alleviate the adverse effects of chilling stress on growth and productivity of coriander. Conclusions It could be suggested that the inducing effect of the pretreatments on hormonal balance triggered an increase in IAA + GA 3 /ABA hormonal ratio. This ratio could be linked and engaged with the protection of cellular metabolic activities from chilling injury against the whole plant life cycle. Therefore, it was speculated that seed priming in humic acid is a powerful technique that can benefit the chilled along with non-chilled plants and sustain the economic importance of coriander plant productivity. | Metabolic activities and molecular investigations of the ameliorative impact of some growth biostimulators on chilling-stressed coriander (Coriandrum sativum L.) plant | 10.1186/s12870-021-03021-6 |
2021-08-07 | Background The root rot of fragrant solomonseal ( Polygonatum odoratum ) has occurred frequently in the traditional P. odoratum cultivating areas in recent years, causing a heavy loss in yield and quality. The phenolic acids in soil, which are the exudates from the P. odoratum root, act as allelochemicals that contribute to the consecutive monoculture problem (CMP) of the medicinal plant. The aim of this study was to get a better understanding of P. odoratum CMP. Results The phenolic acid contents, the nutrient chemical contents, and the enzyme activities related to the soil nutrient metabolism in the first cropping (FC) soil and continuous cropping (CC) soil were determined, and the differentially expressed genes (DEGs) related to the regulation of the phenolic acids in roots were analyzed. The results showed that five low-molecule-weight phenolic acids were detected both in the CC soil and FC soil, but the phenolic acid contents in the CC soil were significantly higher than those in the FC soil except vanillic acid. The contents of the available nitrogen, available phosphorus, and available potassium in the CC soil were significantly decreased, and the activities of urease and sucrase in the CC soil were significantly decreased. The genomic analysis showed that the phenolic acid anabolism in P. odoratum in the CC soil was promoted. These results indicated that the phenolic acids were accumulated in the CC soil, the nutrient condition in the CC soil deteriorated, and the nitrogen metabolism and sugar catabolism of the CC soil were lowered. Meantime, the anabolism of phenolic acids was increased in the CC plant. Conclusions The CC system promoted the phenolic acid anabolism in P. odoratum and made phenolic acids accumulate in the soil. | Physiological and transcriptomic analyses to reveal underlying phenolic acid action in consecutive monoculture problem of Polygonatum odoratum | 10.1186/s12870-021-03135-x |
2021-08-03 | Background Photo-thermo-sensitive genic male sterile (PTGMS) rice ( Oryza sativa L.) is usually considered two-line male sterile rice because of its dual-purpose in two-line hybrid rice system: under short days and low temperatures, it is fertile and used for self-propagation, but under long days and high temperatures, it is sterile and used for hybrid seed production. Therefore, photoperiod and temperature conditions are extremely important for the fertility transition of two-line male sterile rice. In recent years, there have been frequent occurrences of abnormally low-temperature (ALT) resulting in failure of two-line hybrid rice seed production. The daily average temperature (DAT) during ALT events is sometimes higher than the critical sterility-inducing temperature (CSIT) of two-line male sterile rice, of which the night temperature is lower than the CSIT. DAT has been traditionally used as the single indicator of pollen fertility transition, but it is unknown why the fertility of two-line male sterile rice in seed production restored fertility under ALT conditions. Results For Hang93S (H93S), a newly released PTGMS line, we hypothesized fertility transition is determined mainly by the cumulative effective low temperature (ELT) and only a certain duration of low temperature is required every day during the fertility-sensitive period. This study simulated ALTs where the DAT was higher than the CSIT while some segments of night temperature were lower than the CSIT. The results showed H93S exhibited a fertility transition to varying degrees. Moreover, fertility was restored under simulated ALT conditions and pollen fertility increased with increasing cumulative ELT, indicating that the fertility transition was affected primarily by the cumulative ELT. Results also indicated that pollen fertility increased as the number of treatment days increased. Conclusions The fertility transition is caused mainly by the cumulative ELT. In two-line male sterile rice breeding, the effects of day length, ALT at night, and continuous response days should be considered together. The present study provides new insight into fertility transition so breeders can more effectively utilize the two-line male sterile rice, H93S, in breeding programs. | Characteristics of Fertility Transition Response to the Cumulative Effective Low Temperature in a Two-Line Male Sterile Rice Cultivar | 10.1186/s12284-021-00514-8 |
2021-08-03 | To assess the suitability of a newly developed jute–polypropylene blended jute geotextile (JGT) in expansive black cotton (BC) soil as road-subgrade for low volume road construction, several laboratory-based studies were carried out, viz., the effect of pressure on the thickness of the geotextile fabric, long-duration biodegradability of it in saturated BC soil, microscopic study on the biodegraded blended JGT fabrics and finally a moderately long-duration California Bearing Ratio (CBR)-study incorporating experimental geotextile/s inside the compacted BC soil subgrade. Comparative performance of a commercial synthetic geotextile was also studied under similar conditions as that of the blended JGT for determination of the thickness profiles and CBR-study. Biodegradability study reveals that the blended JGT (composed of 77% jute by weight) retains around 81% and 67% of its initial tensile strengths in warp and weft directions respectively, even after remaining embedded in 100% saturated BC soil for 15 months. It has been experimentally found that this blended JGT for single layer application causes about 44% maximum CBR improvement over only soil system. The findings recommend that the blended JGT can be an economical and environment-friendly substitute of 100% synthetic geotextiles in the construction of low volume roads constructed over BC soil subgrade. The extent of CBR improvement and mechanism of reinforcement obtained from this study can guide the road engineers for the design of roads along with supporting field data. | Application of Jute–Polypropylene Blended Geotextile in Black Cotton Soil Subgrade for Low Volume Road Construction | 10.1007/s40891-021-00301-x |
2021-08-03 | Background Bone tissue engineering is a new concept bringing hope for the repair of large bone defects, which remains a major clinical challenge. The formation of vascularized bone is key for bone tissue engineering. Growth of specialized blood vessels termed type H is associated with bone formation. In vivo and in vitro studies have shown that low level laser therapy (LLLT) promotes angiogenesis, fracture healing, and osteogenic differentiation of stem cells by increasing reactive oxygen species (ROS). However, whether LLLT can couple angiogenesis and osteogenesis, and the underlying mechanisms during bone formation, remains largely unknown. Methods Mouse bone marrow mesenchymal stem cells (BMSCs) combined with biphasic calcium phosphate (BCP) grafts were implanted into C57BL/6 mice to evaluate the effects of LLLT on the specialized vessel subtypes and bone regeneration in vivo. Furthermore, human BMSCs and human umbilical vein endothelial cells (HUVECs) were co-cultured in vitro. The effects of LLLT on cell proliferation, angiogenesis, and osteogenesis were assessed. Results LLLT promoted the formation of blood vessels, collagen fibers, and bone tissue and also increased CD31 hi EMCN hi -expressing type H vessels in mBMSC/BCP grafts implanted in mice. LLLT significantly increased both osteogenesis and angiogenesis, as well as related gene expression (HIF-1α, VEGF, TGF-β) of grafts in vivo and of co-cultured BMSCs/HUVECs in vitro. An increase or decrease of ROS induced by H 2 O 2 or Vitamin C, respectively, resulted in an increase or decrease of HIF-1α, and a subsequent increase and decrease of VEGF and TGF-β in the co-culture system. The ROS accumulation induced by LLLT in the co-culture system was significantly decreased when HIF-1α was inhibited with DMBPA and was followed by decreased expression of VEGF and TGF-β. Conclusions LLLT enhanced vascularized bone regeneration by coupling angiogenesis and osteogenesis. ROS/HIF-1α was necessary for these effects of LLLT. LLLT triggered a ROS-dependent increase of HIF-1α, VEGF, and TGF-β and resulted in subsequent formation of type H vessels and osteogenic differentiation of mesenchymal stem cells. As ROS also was a target of HIF-1α, there may be a positive feedback loop between ROS and HIF-1α, which further amplified HIF-1α induction via the LLLT-mediated ROS increase. This study provided new insight into the effects of LLLT on vascularization and bone regeneration in bone tissue engineering. | Low level laser therapy promotes bone regeneration by coupling angiogenesis and osteogenesis | 10.1186/s13287-021-02493-5 |
2021-08-03 | Comparing with conventional formations, the resistivity difference between the oil-bearing reservoir and water-saturated layer is little in the Triassic Chang 3 Member of the Yanchang Formation in Pengyang Region, southwestern Ordos Basin, China. This makes the oil-bearing potential reservoirs’ identification face a great challenge. To understand the genesis that makes the low-resistivity contrast in oil-bearing formations, several core samples are chosen to apply for routine physical property and X-ray diffraction analysis, nuclear magnetic resonance (NMR), and mercury injection capillary pressure (MICP) experimental measurements. Meanwhile, the formation water is also extracted from 19 wells to measure the total salinity and analyze the chemical components. The results illustrate that the Chang 3 Formation contains good pore structure and relative high porosity and permeability (the average porosity is 13.80%, and the average permeability is 6.81 mD). The effect of clay mineral to formation resistivity can be ignored. The main factors that cause low-resistivity contrast in oil-bearing layers are high formation water salinity and formation porosity. Combining the spontaneous potential (SP) with formation deep induction resistivity (RT), a parameter, named as the corrected resistivity index (CRI), is constructed, and the crossplots of reservoir porosity and CRI and flow zone index (FZI) versus CRI are raised to identify low-resistivity contrast oil-bearing layers in the northeastern and southwestern areas, separately. In addition, after normalizing porosity and CRI, the correlation coefficient between these two parameters is also calculated and used to indicate low-resistivity contrast oil-bearing potential layers. After these methods are extended to field applications, the oil-bearing potential formations in the Chang 3 Member are consecutively identified. The identification results match well with the drill stem test (DST) data, verifying the reliability of the proposed methods. | Genesis analysis and identification of low-resistivity contrast oil-bearing reservoirs: a case study in the Triassic Chang 3 Member of the Yanchang Formation in Pengyang Region, Southwestern Ordos Basin, China | 10.1007/s12517-021-08052-9 |
2021-08-02 | In this paper, a modified 1-bit arithmetic and logical unit (ALU) is proposed from the existing designs and a 4-bit ALU has been developed using both CMOS and Sub-Threshold Adiabatic Logic (SAL) in 45nm technology using CADENCE Virtuoso Software. Power and delay analyses are performed in the sub-threshold region of SAL using different power supply voltages and operating frequencies. It is observed that adiabatic logic circuits provide a relative reduction in power consumption when compared with CMOS. The simulation results show that the proposed 4-bit ALU using SAL consumed power 88–91 percent less than CMOS. In terms of performance, the proposed circuit exhibited more delay than CMOS. | Design of 4-bit ALU using sub-threshold adiabatic logic (SAL) | 10.1007/s12046-021-01668-3 |
2021-08-01 | A major roadblock in achieving substantial building energy reduction is the low performance of old buildings that account for a significant portion of the building energy consumption. Finding low-cost energy retrofit solutions that do not disrupt occupants’ daily life during the retrofitting is the key to successful building energy retrofit initiatives. In this paper, a novel and low-cost exterior wall retrofitting solution is introduced, and its performance in reducing space cooling load was quantitatively evaluated to demonstrate its feasibility and effectiveness. The primary goal of this paper is to provide a quantitative assessment of the cooling-energy savings potential by using the proposed new wall system. The intended retrofitting targets are the large amount of existing cavity-wall buildings located in hot climate regions. The quantification of the before-after heat-flux reduction was conducted through a 3-dimensional steady-state low turbulence computational fluid dynamics (CFD) model, which is validated by benchmarking its prediction against the published experimental case results. The outcomes of the investigation suggest that this simple low-cost solution has great potentials in reducing buildings’ summer cooling load in hot climate regions. The applicability of this solution is not limited to retrofitting existing buildings. New energy-efficient building designs can also adopt this solution in their envelope systems. | Assessing cooling energy reduction potentials by retrofitting traditional cavity walls into passively ventilated cavity walls | 10.1007/s12273-020-0740-0 |
2021-08-01 | One of the ways to identify the type of failures and to estimate the lifetime of components is to examine the fracture surface by fractographic analysis. The application of this investigation can be introduced in the prediction of the fatigue lifetime of the vehicle parts, aircraft and marine components, and all other structures that are under cyclic loading. In this study, fracture properties of the aluminum-silicon-magnesium alloy, under strain-controlled low-cycle fatigue loading, were studied considering striations on the fracture surface. This material has been widely used in engine cylinder heads. For this purpose, at the first step, relations and formulations were extracted, including the Paris crack growth law and the distance of the fracture surface striations. After measuring striation spacing from the experimental data of the low-cycle fatigue test for aluminum alloys (with and without heat treatment), the material constants of the Paris law were calculated and calibrated. The obtained results of the lifetime estimation, as compared to the experimental fatigue lifetime, stated that the scatter-band was 1.4X, which indicated the accuracy of the proposed model with an average error of 15%. | Estimation of Low-Cycle Fatigue Lifetime in Aluminum-Silicon-Magnesium Alloy of Cylinder Heads based on Striation Marks as Failure Features of Fracture Surfaces and Paris Crack Growth Law | 10.1007/s11668-021-01196-6 |
2021-08-01 | The discovery of the Meissner (Meissner–Ochsenfeld) effect in 1933 was an incontestable turning point in the history of superconductivity. First, it demonstrated that superconductivity is an unknown before equilibrium state of matter, thus allowing to use the power of thermodynamics for its study. This provided a justification for the two-fluid model of Gorter and Casimir, a seminal thermodynamic theory founded on a postulate of zero entropy of the superconducting (S) component of conduction electrons. Second, the Meissner effect demonstrated that, apart from zero electric resistivity, the S phase is also characterized by zero magnetic induction. The latter property is used as a basic postulate in the theory of F. and H. London, which underlies the understanding of electromagnetic properties of superconductors. Here the experimental and theoretical aspects of the Meissner effect are reviewed. The reader will see that, in spite of almost nine decades age, the London theory still contains questions, the answers to which can lead to a revision of the standard picture of the Meissner state (MS) and, if so, of other equilibrium superconducting states. An attempt is made to take a fresh look at electrodynamics of the MS and try to work out with the issues associated with the description of this most important state of all superconductors. It is shown that the concept of Cooper’s pairing along with the Bohr–Sommerfeld quantization condition allows one to construct a semi-classical theoretical model consistently addressing properties of the MS and beyond, including non-equilibrium properties of superconductors caused by the total current. As follows from the model, the three “big zeros” of superconductivity (zero resistance, zero induction and zero entropy) have equal weight and grow from a single root: quantization of the angular momentum of paired electrons. The model predicts some yet unknown effects. If confirmed, they can help in studies of microscopic properties of all superconductors. Preliminary experimental results suggesting the need to revise the standard picture of the MS are presented. | Meissner Effect: History of Development and Novel Aspects | 10.1007/s10948-021-05925-8 |
2021-08-01 | The stability of gradient grain microstructure on the surface of low carbon steel was studied by different annealing temperature and high temperature friction and wear experiments. The results showed that the surface grain of the low-carbon steel was refined, and the microhardness reached 250 HV. An increase in the annealing temperature, the gradient refined grain microstructure of the surface layer gradually disappeared. When the annealing temperature was lower than 300 °C, the average grain size increased continuously from the surface to the center without obvious interface. The surface layer hardness could reach about 220 HV. However, when the annealing temperature reached 500 °C, the refined microstructure of the surface layer completely disappeared. At the same time, the grain boundaries could be seen clearly indicating the refined grain in the surface layer had recrystallized. Compared with the as-prepared, the grain size of the surface layer grew up and the microhardness reduced to about 150 HV. Moreover, the wear behavior of the gradient refined grain microstructure at high temperature also proved that the disappearance of the surface refined grain leads to an increase in the wear volume at higher temperature. | Study on the Stability of Microstructure and Mechanical Properties of Gradient Refined Microstructure on Low-Carbon Steel Surface | 10.1007/s11665-021-05817-x |
2021-08-01 | The oil and gas production has grown steadily, and the care with its transportation grid needs to be maintained and expanded. The pipeline used in the transport of gas and oil by-product requires materials with high mechanical strength, toughness, and fatigue resistance. The chemical composition and distribution, amount, and morphology of the final microconstituents of the steel are of paramount importance once it will directly influence the mechanical properties. The fracture toughness is one of the most important mechanical properties for the suitability of the steel for pipeline usage, and is most of the literature with pipelines study does not present tests such as crack tip opening displacement (CTOD), with a steady and controlled crack growth behavior, to evaluate its fracture toughness. This study compares the fracture toughness of the API 5L X70 steel between two plates of steel with different Nb content, 0.06 and 0.09 Nb wt.% by CTOD tests. The mechanical response was correlated to the grain size and distribution. The CTOD parameter was used to assess the fracture toughness at 25 °C and − 60 °C. The microstructures and microconstituents of the two plates of steel were similar. The matrices were composed of ferrite, with bands of secondary products, including degenerated pearlite. Results showed a prone to the formation of a bimodal microstructure, coarse and fine grains, due to the addition of Nb. High-Nb steel presented better fracture toughness than normal-Nb steel at low-temperature. | Microstructure and Mechanical Properties of Nb-API X70 Low Carbon Steel | 10.1007/s13632-021-00761-7 |
2021-08-01 | The relationship between microstructure and corrosion behavior of high-grade pipeline steel under low-temperature conditions was comparatively investigated by the potentiodynamic polarization and electrochemical impedance spectroscopy test combining with optical micrographs, scanning electron microscopy, transmission electron microscopy and electron back-scattered diffraction. The results showed that, compared with room and high temperature, low temperature could influence the corrosion behavior of high-grade pipeline steel, which means that the corrosion potential and current density decreased and the corrosion resistance increased significantly. Moreover, double layer structures of the interface became thicker and more compact. Under low-temperature environment, acicular ferrite had the martensite/austenite constituents with less amount and smaller size, a higher density of low angle grain boundaries and smaller effective grain sizes compared with granular bainite, which demonstrated higher corrosion resistance. | Relationship between microstructure and corrosion behavior of high-grade pipeline steel in a low-temperature environment | 10.1007/s42243-021-00621-2 |
2021-08-01 | Abstract The effect of complex additives based on cobalt, iron, and manganese oxides and sodium silicate on the phase composition, microstructure, mechanical properties, and sintering of tetragonal zirconia ceramics stabilized with 3 mol % yttria and containing 10 wt % alumina (3Y–TZP–10Al 2 O 3 ) was studied. The introduction of complex additives significantly affected sintering of the ceramics: the open porosity was less than 1% after annealing at 1250°C. The use of Na 2 Si 2 O 5 –0.33% Mn as a sintering additive provided the minimum of porosity for sintering temperature of 1300°C. Ceramics with flexural strength of 500 ± 16 MPa and the microhardness of 10 GPa was obtained. | Effect of Complex Additives Based on Iron, Cobalt, and Manganese Oxides and Sodium Silicate on the Sintering and Properties of Low-Temperature Ceramics 3Y–TZP–Al2O3 | 10.1134/S0036023621080192 |
2021-08-01 | Waste heat recovery systems are proposed to be an environmentally benign and a cost-effective application for efficiency improvement of energy conversion systems. In this research, three different subsystems—gas turbine cycle, steam Rankine cycle, and a coupled organic Rankine cycle–vapor compression refrigeration—are integrated to obtain a high-efficiency layout from technical, economic, and environmental viewpoints. The whole system is simulated and analyzed with regard to energy, exergy, and exergoeconomic models. Furthermore, a sensitivity analysis is made to enable a better understanding of the effect of design parameters on the final performance of the total system. Based upon a parametric study, R602 demonstrates advantageous features such as higher thermal efficiency and improved exergetic efficiency in the ORC–VCR subsystem. Overall, analyses show that the proposed integrated system obtains the total energy and exergy efficiencies of 46.1% and 40.57%, respectively. Moreover, it has been illustrated that the overall structure is able to provide a 3810 kW net output power and a 303.8 kW cooling load. Besides, exergoeconomic evaluation depicts an exergy cost of 49.84 ($ GJ −1 ) and an exergy cost rate of 826.4 ($ h −1 ). | Thermodynamic and exergoeconomic analyses and performance assessment of a new configuration of a combined cooling and power generation system based on ORC–VCR | 10.1007/s10973-020-10230-y |
2021-08-01 | Oil spills into ocean or coastal waters can result in significant damage to the environment via pollution of aquatic ecosystems. Absorbents based on reduced graphene oxide (rGO) foams have the capacity to remove minor or major oil spills. However, conventional chemical synthesis of rGO often uses petrochemical precursors, potentially harmful chemicals, and requires special processing conditions that are expensive to maintain. In this work, an alternative cost-effective and environmentally friendly approach suitable for large-scale production of high-quality rGO directly from used cooking sunflower oil is discussed. Thus, produced flaky graphene structures are effective in absorbing used commercial sunflower oil and engine oil, via monolayer physisorption in the case of used sunflower and engine oils facilitated by van der Waals forces, π–π stacking and hydrophobic interactions, π-cation (H + ) stacking and radical scavenging activities. From adsorption kinetic models, first-order kinetics provides a better fit for used sunflower oil adsorption ( R 2 = 0.9919) and second-order kinetics provides a better fit for engine oil adsorption ( R 2 = 0.9823). From intra-particle diffusion model, R 2 for USO is 0.9788 and EO is 0.9851, which indicates that both used sunflower and engine oils adsorption processes follow an intra-particle diffusion mechanism. This study confirms that waste-derived rGO could be used for environmental remediation. | Growth of rGO nanostructures via facile wick and oil flame synthesis for environmental remediation | 10.1007/s42823-021-00244-3 |
2021-08-01 | Oxidation of the Fe-base alloy T22 in humid air at 500 °C was investigated. The samples were exposed for up to 1000 h at 1 bar and 20 bar. The influence of three furnace tube materials, alumina, ET45 and quartz glass, on the oxide scale morphology was investigated. Samples and their cross sections were examined using optical microscopy, scanning electron microscopy, electron probe micro analysis and Raman spectroscopy. Multilayered oxide scales consisting of hematite, magnetite and Fe–Cr spinel were found on all samples. However, the composition and morphology of the oxide scales depend on the furnace tube material and on the system pressure. The system pressure is assumed to change the reaction equilibria and adsorption rates. The tube material changed the initial gas composition by formation of volatile Cr species. This volatilization rate increased at higher system pressures. | Effect of Total Pressure and Furnace Tube Material on the Oxidation of T22 in Humidified Air | 10.1007/s11085-021-10036-9 |
2021-08-01 | Abstract A simple low-temperature (< 100 °C) hot-water treatment was used to synthesize Fe–N co-doped anatase nanocrystals which were uniformly dispersed in micro–mesoporous SiO 2 host film for the first time. The Fe–N co-doped TiO 2 –SiO 2 (FNTS) film exhibited stable photocatalytic activities. A NO removal efficiency of 56.1% was achieved under simulated solar light irradiation without any obvious inactivation in 30 min. The transient photocurrent response of FNTS film is approximately six times higher than that of non-doped TiO 2 –SiO 2 film, indicating the superior charge separation of photo-generated electron–hole pairs. Electron spin resonance analysis showed that the ·OH and ·O 2 − radicals were key species to remove NO. Combined with quantitative reaction intermediates, the possible photocatalytic degradation mechanism of NO over FNTS film was proposed. In addition, the FNTS thin films exhibited intrinsic super-hydrophilicity and durable self-cleaning property even after 6 months of storage in the dark. This work provides a facile method to load the catalyst on thermal labile substrates, such as soda–lime glass and organic polymer for more practical applications. Graphic Abstract A simple low-temperature (< 100 °C) hot-water treatment was used to synthesize micro–mesoporous TiO 2 –SiO 2 composite film, which shows good self-cleaning ability and superior photodegradation activity for NO removal under solar light. | Low-Temperature Synthesis of Micro–Mesoporous TiO2–SiO2 Composite Film Containing Fe–N Co-Doped Anatase Nanocrystals for Photocatalytic NO Removal | 10.1007/s10562-020-03466-8 |
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