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2021-10-01 | This work shows that the titanium dioxide coatings obtained by low-pressure cold gas spraying with the use of the sol–gel amorphous TiO 2 powder are characterized by photocatalytic activity despite their partial amorphous content. Moreover, the research outcome suggests that the decomposition rate of organic pollutants is enhanced after long-term exposure to moisture. The condensation humidity test is not detrimental to the continuity and integrity of the coating, but the phase composition of coatings changes—with the exposure to water vapor, the portion of the amorphous phase crystallizes into brookite. The mechanism responsible for the conversion of amorphous TiO 2 into brookite is attributed to the water-driven dissolution and reprecipitation of TiO 6 octahedra. It has been shown that an additional parameter necessary for the stabilization of the brookite is the oxygen depletion of the amorphous structure of titanium dioxide. Considering the results presented in this paper and the advantages of a portable, low-pressure cold spray system for industrial applications, it is expected that TiO 2 coatings produced from a sol–gel feedstock powder can be further developed and tested as efficient photocatalysts. | Photocatalytic Activity Enhancement of Low-pressure Cold-Sprayed TiO2 Coatings Induced by Long-term Water Vapor Exposure | 10.1007/s11666-021-01244-5 |
2021-10-01 | In this study, vapor recompression and heat integration assisted distillation arrangements with either the low or high pressure in the reflux drum are proposed to reduce and/or eliminate the application of the costly refrigerant for the separation of n -heptane and isobutanol mixture. The high-pressure arrangement with vapor recompression and heat integration is the most attractive among these four intensified configurations since it can reduce total annual cost by 18.10%, CO 2 emissions by 75.01% based on natural gas (78.78% based on heavy oil fuel), and second-law efficiency by 61.20% compared to a conventional refrigerated distillation system. Furthermore, exergy destruction in each component is calculated for the heat integration configurations and is shown in pie diagrams. The results demonstrate that the high-pressure configuration presents unique advantages in terms of thermodynamic efficiency compared to the low-pressure case. In addition, dynamic control investigation is performed for the economically efficient arrangement and good product compositions are well controlled through a dual-point temperature control strategy with almost negligible product offsets and quick process responses when addressing 20% step changes in production rate and feed composition. Note that there are no composition measurement loops in our developed control schemes. | Separation of n-heptane/isobutanol via eco-efficient vapor recompression-assisted distillation: process optimization and control strategy | 10.1007/s11705-020-2018-6 |
2021-10-01 | An easy method is presented for producing gold nanoparticles. We show that by performing simultaneous low-temperature heating of a quartz glass substrate on which the dry residue of a 10 μL droplet of an HCl acidic solution of HAuCl 4 ·4H 2 O is deposited and a counter substrate using Peltier devices in a low vacuum produced by a rotary pump, gold nanoparticles with sizes ranging from about twenty to one hundred and several tens of nanometers are produced on the counter substrate. In this study, an application of a gold nanoparticle substrate produced by this method to the sample holder for surface-enhanced Raman scattering analysis is also shown. | Gold Nanoparticles Produced by Low-temperature Heating of the Dry Residue of a Droplet of an HCl Acidic Solution of HAuCl4·4H2O in a Low Vacuum | 10.2116/analsci.20P458 |
2021-10-01 | Abstract A finite-element mathematical model is developed to describe the transformation of the surface cracks of continuously cast slabs made of low-alloy pipe steels into sheet defects during hot rolling. The transformation of axial, edge, rib, and side cracks of a slab is investigated. It is found that, depending on the deformation conditions, surface cracks on rolling a slab into a thick sheet can close in the first passages under compressive stresses, come to the surface, form folds, twist toward the edge, or completely rolled out. | Transformation of the Surface Cracks of in Continuously Cast Slabs Made of Low-Alloy Pipe Steels during Hot Rolling | 10.1134/S0036029521100116 |
2021-10-01 | The effect of ferrite and martensite hardening variation on the mechanism of void formation in a low-carbon low-alloy steel with different ferrite–martensite dual-phase (DP) microstructures has been investigated. Accordingly, several ferrite–martensite DP microstructures containing a wide range of martensite volume fractions ( V m ) from 23% to 87% were developed by application of intercritical annealing heat treatment processes. Optical and field-emission scanning electron microscopy were supplemented by hardness measurements and tensile testing to follow the microstructural changes and correlate them with the mechanism of void formation. The experimental results indicate that the mechanism of void formation changes from ferrite/martensite (F/M) interface decohesion to martensite cracking as V m increases in the microstructures. For DP specimens containing low V m , F/M interface decohesion is the dominant mechanism of void formation, while in DP samples with moderate level of V m , both mechanisms of F/M interface decohesion and martensite cracking are involved in the void formation. In DP samples containing high V m , void nucleation and growth due to martensite cracking is the dominant damage mechanism. This change in the void formation mechanism with V m can be rationalized based on the change in the plastic behavior of ferrite and martensite microphases developed as a consequence of ferrite and martensite hardening variation. The martensite hardening response decreases monotonically with increasing V m from 23% to 87%, while that of ferrite shows an increasing trend up to 73% then decreases with further increase up to 87%. | Effect of Ferrite and Martensite Hardening Variation on Mechanism of Void Formation in Low-Alloy Dual-Phase Steel | 10.1007/s13632-021-00779-x |
2021-10-01 | In low-frequency vibration-assisted drilling (LFVAD) of CFRP/Ti6Al4V stacks, owing to the different mechanical and thermal performances of the involved carbon fiber–reinforced plastic (CFRP) composite and Ti6Al4V alloy, the short tool life of commonly used carbide (WC) tools and rapidly deteriorated machining quality are the major problems. This paper aims to explore whether the polycrystalline diamond (PCD) tool can achieve a competitive effect on drilling CFRP/Ti6Al4V stacks compared with previous CFRP drilling studies. To avoid the frequent occurrence of chisel edge fracture in LFVAD of Ti6Al4V alloy, a model of plowing behavior is established and parametric experiments based on it are performed with both PCD and WC drills. It is found that the periodically dynamic force is the major factor causing the chisel edge fracture of the PCD drill, which can be alleviated by reducing the feed rate. Besides, by using PCD drills instead of WC drills in Ti6Al4V drilling, the exit burr height, drilling diameter deviation, and surface roughness value are reduced under each given parameter. Finally, PCD and WC drill bits are used to perform a wear test on the CFRP/Ti6Al4Vstacks under optimized parameters. The PCD drill achieves superior performance, including lower wear rate, better hole quality, and higher consistency. The experiments discussed in this paper provide some suggestions for selecting tools and cutting parameters when drilling CFRP/Ti6Al4V stacks. | Machining performance of PCD drill in low-frequency vibration-assisted drilling of CFRP/Ti6Al4V stack: with special emphasis on the plowing behavior | 10.1007/s00170-021-07603-4 |
2021-10-01 | Chemical transmission lines, petroleum and natural gas lines, pressure vessels, and pipes used in thermal facilities are expected to maintain their mechanical properties for many years without being damaged and not to be corroded in working conditions. The composite materials are the right candidate for these harsh conditions due to their superior properties. Reinforcement of nanoadditives to composite materials improves both the mechanical properties and the resistance to environmental conditions, thereby increasing the lifetime. In this study, multi-walled carbon nanotube (MWCNT) reinforced [± 55°] carbon fiber/epoxy composite pipes produced with filament wound method were used. It was hydrothermally aged in 80 °C distilled water for 1, 2, 3 weeks in order to examine the effect of environmental conditions. In order to investigate its resistance against loads that may occur in working conditions, ring tensile tests (ASTM D 2290–16 procedure A), and low-velocity impact tests at 5, 10, 15 J, energy levels were carried out. The effect of hydrothermal aging on neat and MWCNT added epoxy composite had been examined by considering the aging period. Consequently, the impact resistance of neat and MWCNT added samples decreased with the aging process. Besides, tangential tensile strength loss was 17% in MWCNT reinforced sample and 13% in the neat sample. | The Effect of Hydrothermal Aging on the Low-Velocity Impact Behavior of Multi-Walled Carbon Nanotubes Reinforced Carbon Fiber/Epoxy Composite Pipes | 10.1007/s10443-021-09923-w |
2021-10-01 | The current work addresses a statistically optimized, economic, and efficient approach for the professional valorization of the massively accumulated non-efficiently utilized, raw agro-industrial waste rice husk (RH). Thermomyces lanuginosus strain A3-1 DSM 105773, a locally isolated strain, was employed for directed production of xylanase, an industrially important enzyme upon growing on RH-based medium. A three-step empirical sequential, statistical approach—one variable at a time (OVAT), Plackett–Burman design (PBD), and Box–Behnken design (BBD)—was employed to optimize the xylanase production through liquid-state fermentation of rice husk. Incubation temperature (50 °C) and ammonium sulfate concentration as an inorganic nitrogen source were the most appropriate parameters triggering the production of xylanase, deduced from OVAT. The three key determinants RH concentration, initial pH of the production medium, and incubation time did exhibit significant influences ( P ≤ 0.001) on the production of xylanase, deduced from PBD. By the end of the optimization process, the optimal levels of RH, initial pH of the production medium, and incubation time were 3.8% (w/v), 4.5, and 8 days, respectively, with an agitation speed of 120 rpm to achieve a maximal xylanase level of 0.8344 U/mL with a fivefold enhancement deduced from the estimated ridge of the canonical path. Present data would reinforce the scaling up of xylanase production using the present powerful and reproducible approach for the simultaneous and proficient valorization of RH and production of xylanase for further exploitation in food, pharmaceutical, and textile industries. | Biovalorization of the raw agro-industrial waste rice husk through directed production of xylanase by Thermomyces lanuginosus strain A3-1 DSM 105773: a statistical sequential model | 10.1007/s13399-020-00824-9 |
2021-10-01 | Straw charcoal was used as a novel reductant in the co-reduction roasting of laterite ore and red mud. The influence of the reductant dosages, co-reduction temperature, and co-reduction time were investigated. Results showed that a powdered ferronickel product of 1.81wt.% nickel and 81.40wt.% iron was obtained under straw charcoal dosage of 15wt.% and roasted at 1250 °C for 80 min. The corresponding recovery of nickel and total iron were 97.21wt.% and 98.87wt.%, respectively. The performance of straw charcoal was also compared to that by the conventional coke reductant. Results showed that ferronickel particles using straw charcoal were larger in size than coke, mainly due to the lower S (0.14wt.%) and ash content (3.80wt.%), which could not hinder the agglomeration of the ferronickel grains, and lower melting point that producing liquid phase and promoting ferronickel particles growth. In addition, the gasification reactivity of straw charcoal is better than that of coke, which is beneficial to the iron oxide reduction and the recovery of iron. To conclude, straw charcoal is a promising reductant for the co-reduction of laterite ore and red mud in coal-deficient areas. | Study of Straw Charcoal as Reductant in Co-reduction Roasting of Laterite Ore and Red Mud to Prepare Powdered Ferronickel | 10.1007/s42461-021-00466-z |
2021-10-01 | Abstract The peculiarities of strain aging of low-alloy pipeline steels with various structural states (ferritic–pearlitic, bainite) are studied. During strain aging, the steels demonstrate a decrease in the mechanical properties and the impact toughness and the degradation of cold resistance, which are most pronounced in the steel with a bainitic structure. A special method is used to analyze the influence of the strain rate during static loading on the yield strength of the steel in the initial state and after strain aging. | Effect of Strain Aging on the Rate Dependence of the Strain Resistance and the Cold Resistance of Low-Carbon Steels with Ferritic–Pearlitic and Bainitic Structures | 10.1134/S0036029521100232 |
2021-10-01 | In this paper, we firstly present a block robust structured multifrontal factorization method (in brief, BRSMF) using block diagonalonal structure of three temperature matrices, and then we propose a multi-core parallelization of BRSMF (in brief, MBRSMF) method based on the current mainstream parallel computer multi-core architecture. MBRSMF method parallelizes the nested dissection ordering, symbolic decomposition and numerical decomposition of BRSMF method, which aims to effectively solve three temperature linear systems on the multi-core computer. The multi-core parallelization of symbolic decomposition and numerical decomposition is based on the binary elimination tree. Theoretical analysis proves MBRSMF method has better load balancing capability. Numerical experiments show that the MBRSMF method is effective. | Multi-core parallel BRSMF method for 2D3T radiation diffusion equations | 10.1007/s11276-021-02646-7 |
2021-10-01 | Abstract The goals of this study were to quantify and explain the effects of microstructure on the resistance of low-carbon steels to low-cycle fatigue and to extremely low-cycle fatigue (ELCF). Three different microstructures (ferrite–pearlite, ferrite–martensite, and ferrite–bainite–martensite) were tested, and their fatigue properties were analyzed using the strain-based Coffin–Manson model and an energy-based model. According to the Coffin–Manson model, ferrite–pearlite showed the best ELCF resistance, whereas in the energy-based model that considers the effect of tensile strength ferrite–bainite–martensite revealed the highest ELCF resistance. At similar tensile strength, ferrite–bainite–martensite had longer ELCF life than ferrite–martensite; the difference may be a result of the smaller strain incompatibility between bainite and ferrite than between ferrite and martensite. In all three microstructures, cracks initiated at the surface and propagated into the interior; this result indicates that fracture mode was not altered during cyclic loading at high strain amplitudes. Ferrite–martensite microstructure developed many sub-cracks surrounding a main crack; they could facilitate propagation of a main crack, and thereby degrade fatigue life at high strain amplitudes. Graphic Abstract | Influence of Microstructure on Low-Cycle and Extremely-Low-Cycle Fatigue Resistance of Low-Carbon Steels | 10.1007/s12540-020-00819-1 |
2021-10-01 | Hydroxyapatite (camel bone, CB) was used for production of low cost activated carbon (CBC) and applied for vanadium removal from aqueous solution. Nitric acid, phosphoric acid and hydrogen peroxide were used as chemical catalysts to prepare the developed activated carbon. CB and CBC adsorbents were characterized using different available techniques such as SEM, FTIR, N 2 adsorption and desorption isotherms, as well as TGA-DTA thermal analysis. The efficiency of the prepared adsorbent was investigated using batch adsorption method. At optimum pH, CBC could adsorb 85% of vanadium after 30 min. Three isotherm models, namely Freundlich, Langmuir and Dubinin–Radushkevich, were used to analyze the sorption equilibrium data. The process was found to follow Langmuir adsorption isotherm model, indicating that vanadium ions adsorption process had physical character. The kinetic studies manifested that the adsorption process follows the pseudo-second-order reaction. The CBC adsorbent exhibited a feasible capacity (19.45 mg/g) for vanadium adsorption compared to the other works published in the literature. In addition, thermodynamic studies explained that adsorption process is spontaneous, exothermic and occurs preferably via physisorption mechanism. 0.5 M HCl solution was successfully used as eluting agent for vanadium desorption. | Vanadium(V) removal and recovery by adsorption onto modified activated carbon derived from natural hydroxyapatite | 10.1007/s13738-021-02227-7 |
2021-10-01 | Ni-based catalysts are the most promising catalysts for CO 2 methanation. The development of catalysts with low-temperature activity could bring significant energy and environmental benefits. In this work, the hydrogenation of CO 2 to methane was studied on Ni-M/γ-Al 2 O 3 (M = Fe, Co, or Mn) bimetallic catalysts. The optimum reaction was obtained using Ni-Mn/γ-Al 2 O 3 (CO 2 conversion: 85%, CH 4 selectivity: 99%, 280 °C). In situ FTIR studies revealed the excellent performance of Ni-Mn/γ-Al 2 O 3 , which lowers the required reaction temperature. Based on in situ FTIR studies, CO 2 methanation proceeded over three intermediates on the catalysts: bicarbonate → carbonate → formate → methane. The second metal (Co or Mn) promoted the dispersion of both Ni and itself and improved the ability of Ni to crack H 2 . And introduced more oxygen vacancies to strengthen the basicity of surrounding O 2− on the surface of the catalysts. In effect, the number of carbonate active sites could be increased accordingly, thereby improving the adsorption capacity for CO 2 . Graphic Abstract | In-Situ FTIR Study of CO2 Adsorption and Methanation Mechanism Over Bimetallic Catalyst at Low Temperature | 10.1007/s10562-021-03539-2 |
2021-10-01 | Crumb rubbers exhibit extensive potential applications as infrastructure materials due to the low elastic modulus. Nevertheless, the poor interfacial adhesion between rubber crumb and cement matrix limits the scale applications of crumb rubbers in cement-based composites. In this study, mussel-inspired modification of crumb rubbers is investigated. The hydrophilicity of rubber surface has apparently improved after polydopamine (PDA) modification. Effects of the surface modifications of rubbers on the compressive strength, fluidity, and tribology behaviors of rubberized mortars have been systematically characterized. The superiority of PDA modification for crumb rubbers has been demonstrated by comparing those with the other polyphenol modifications and the routine oxidation modification. The compressive strength of the PDA modified rubber cement mortar increases by 37% comparing with that of the ordinary rubber cement mortar. The mechanical and low-temperature tribology behaviors of PDA-rubberized mortars indicate a promising way to improve the service performance of the rubberized mortars and concretes. | Mussel Inspired Modification of Rubber Crumbs for Improved Interfacial Adhesion in Rubber Cement Mortar | 10.1007/s10443-021-09938-3 |
2021-10-01 | The aim of this article was to assess low-velocity impact resistance in polymer composites in the presence of voids, reporting residual mechanical and impact properties, comparing the results with other literature materials and determining the extent to which voids influenced the final result. Thus, three composites with 11 layers were developed, two hybrids (IAYKG) with 3 layers of bidirectional hybrid kevlar/glass strands (intraply/yarn) placed in the middle and outer layers of the laminate, and 8 layers bidirectional fabric with different sized glass fibers, which influenced their void percentage (9 and 4%, respectively), in addition to a non-hybrid composite containing only glass fiber (WG). The tests were carried out using four impact energies (46, 62, 76 and 101 J) until total perforation. As a result, the hybrid yarn improved impact resistance and increased void content (9%), thereby relieving stresses and decreasing damage propagation. | Study of an Intraply/Yarn Composite Submitted to Low-Velocity Impact in the Presence of High Void Content | 10.1007/s11665-021-05923-w |
2021-10-01 | Abiotic stress, such as drought, salt, and cold, affects normal plant growth. Ethylene response factors (ERFs) play an important role in the responses of plants to different stresses. An ERF gene was cloned from Malus baccata (L.) Borkh and named as MbERF12 . A subcellular localization study proved that MbERF12 was a nucleus-localized protein. The expression level of MbERF12 was higher in stems and roots, which was markedly affected by high salinity, low temperature, and ethephon treatments. When MbERF12 was transformed into Arabidopsis thaliana , it obviously improved salt and low-temperature tolerance in transformed plants . Overexpression of MbERF12 in transformed A. thaliana also led to higher levels of peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD) and higher contents of ethylene, chlorophyll, and proline, while the content of malondialdehyde (MDA) was lower, especially when being dealt with low-temperature and high-salinity stresses. MbERF12 plays a key role in the response to salt and cold stresses in Arabidopsis by improving the scavenging ability for reactive oxygen species (ROS) through ethylene signal transduction. We proposed that MbERF12 may function as a positive regulator for abiotic stress responses and can be considered as a potential gene for improvement of cold and high-salinity tolerance in plants. | Overexpression of MbERF12, an ERF gene from Malus baccata (L.) Borkh, increases cold and salt tolerance in Arabidopsis thaliana associated with ROS scavenging through ethylene signal transduction | 10.1007/s11627-021-10199-9 |
2021-10-01 | How to mitigate anthropogenic carbon emissions in cities determines to a large degree whether global temperature targets in this century are to be met. Using 12 cities in or outside China as case studies, we quantified the critical processes of carbon metabolism based on the urban carbon metabolism assessment framework (CMAF) proposed. The differences of sector contribution, and per capita and intensity among carbon throughflows, carbon inflows and carbon emissions were evaluated. Furthermore, we established an indicator system for CMAF consisting of flow-based and structural indicators to compare the low-carbon performances of cities. The results showed that the total carbon throughflow (TCT) and total carbon inflow (TCI) in Chinese cities were 7–12% higher than in European and American cities regarding the manufacturing and services sector on average, but 6–9% lower in the household consumption sector. Beijing, Tianjin, Nanjing and Guangzhou had lower per capita TCT and TCI than in European and American cities such as Paris and Los Angeles, while their carbon intensities were about three times as much. The per capita TCT in a city was found significantly correlated with per capita energy consumption and had a certain correlation with per capita building or housing area. This study found that TCT, TCI and carbon dioxide emission each provided unique information to measure the potential climatic impact of cities. The difference in the ranking of low-carbon performance between the investigated cities was significant both in terms of flow-based and structural indicators. We suggest these assessment indicators of carbon metabolism be integrated into urban resources management to reflect both the decarbonization status and future emission reduction potential more accurately and to provide systemic decision support for achieving the goal of carbon neutrality in cities. | Assessing urban low-carbon performance from a metabolic perspective | 10.1007/s11430-020-9807-y |
2021-10-01 | There is a large demand for the utilization of biowaste to separate salts and dyes from wastewater. The biowaste of eggshell membrane (ESM) was derived from chicken eggshell, and the ESM solution in dimethyl sulfoxide (DMSO) was incorporated into polyethersulfone (PES) membranes to improve their material and separation properties. The PES membrane was prepared with different volumes of the ESM/DMSO solution (0.5, 1, and 1.5 mL) and was added to prepare three modified PES membranes using the phase inversion method. The reduction in the contact angle from 63.7 to 48.7° was accompanied by improvement in hydrophilicity of the modified PES membranes. These PES/ESM blend membranes were characterized based on porosity, swelling ability, and morphology. Thermogravimetric analysis (TGA) and Fourier-transform infrared (FTIR) spectroscopy helped determine the thermal stability and structural changes, respectively, of the modified PES membranes. The separation of methylene blue and sulforodamine B dyes and NaCl and MgSO 4 salts by using PES and PES/ESM membranes were studied. The modified PES/ESM membranes exhibited higher flux rates for all the dyes and salts tested. | Effective separation of salts and dye using egg shell membrane (ESP) incorporated polyethersulfone polymer material | 10.1007/s42247-020-00137-7 |
2021-10-01 | Scarcity of arable land, limited soil nutrient availability, and low-temperature conditions in the Himalayan regions need to be smartly managed using sustainable approaches for better crop yields. Microorganisms, able to efficiently solubilize phosphate at low temperatures, provide an opportunity to promote plant growth in an ecofriendly way. In this study, we have investigated the ability of psychrotolerant Pseudomonas spp., isolated from high altitudes of Indian Himalaya to solubilize P at low temperature. Quantitative estimation of phosphate solubilization and production of relevant enzymes at two different temperatures (15 and 25 °C) was performed for 4 out of 11 selected isolates, namely, GBPI_506 ( Pseudomonas sp.), GBPI_508 ( Pseudomonas palleroniana ), GBPI_Hb61 ( Pseudomonas proteolytica ), and GBPI_CDB143 ( Pseudomonas azotoformans ). Among all, isolate GBPI_CDB143 showed highest efficiency to solubilize tri-calcium phosphate (110.50 ± 3.44 μg/mL) at 25 °C after 6 days while the culture supernatants of isolate GBPI_506 displayed the highest phytase activity (15.91 ± 0.35 U/mL) at 15 °C and alkaline phosphatase (3.09 ± 0.07 U/mL) at 25 °C in 6 and 9 days, respectively. Out of five different organic acids quantified, oxalic acid and malic acid were produced in maximum quantity by all four isolates. With the exception of GBPI_508, inoculation of bacteria promoted overall growth (rosette diameter, leaf area, and biomass) of Arabidopsis thaliana plants as compared to uninoculated control plants in growth chamber conditions. The plant growth promotion by each bacterial isolate was further validated by monitoring root colonization in the inoculated plants. These bacterial isolates with low-temperature phosphate solubilization potential along with phosphatases and phytase activity at low temperature could be harnessed for sustainable crop production in P-deficient agricultural soils under mountain ecosystems. | Plant Growth Promotion at Low Temperature by Phosphate-Solubilizing Pseudomonas Spp. Isolated from High-Altitude Himalayan Soil | 10.1007/s00248-021-01702-1 |
2021-10-01 | The value and role of mosquito meshes in low resource and poor income settings | 10.1007/s10029-020-02323-2 | |
2021-10-01 | Automated Fibre Placement is a common manufacturing technique for composite parts in the aero-space industry. Therefore, a visual part inspection is required which often covers up to 50% of the actual production time. Moreover, the inspection quality of this manual step fluctuates significantly. A camera-based automated inline inspection is capable of increasing the inspection efficiency and accuracy. However, the interpretability of the acquired data strongly depends on the sensor configuration and the inspected material. Thus, this paper introduces methods for modelling and assessing an imaging sensor on the example of a composite material reflecting a spot laser to a camera sensor. In this context, the reflection properties of the material are incorporated into a simulation and validated in comparison to real camera images from the experimental setup. The EMVA 1288 sensor model in combination with the Cramér–Rao lower bound indicates a feasible estimability of the beam propagation, but shows limitations in the predictability of the number of incident photons. The laser spot analysis indicated that the laser spot can deviate from an exact oval shape but its peak value is suitable for robust spot identification in an image. The outlined methodology is also adaptable to other imaging sensors, illumination sources and materials. Thus, the findings can be useful for other fields and manufacturing processes. | Imaging sensor data modelling and evaluation based on optical composite characteristics | 10.1007/s00170-021-07591-5 |
2021-10-01 | This study empirically examines the impact of climate change on cereal production in selected lower-middle-income countries with a balanced panel dataset spanning 1971–2016. The study uses average annual temperature and rainfall to measure climate change. Besides this, CO 2 emissions, cultivated land under cereal production, and rural population are used as the control variables. Second-generation unit root tests, i.e., CIPS and CADF, are used to test the stationarity of the variables. Feasible generalized least square (FGLS) and fully modified ordinary least square (FMOLS) models are used to achieve the objective. Pedroni cointegration test confirms the presence of cointegration between cereal production and climate change variables. The findings show that a rise in the temperature reduces cereal production in lower-middle-income countries. In contrast, rainfall and CO 2 emissions have a positive effect on cereal production. For robustness purpose, the Driscoll-Kraay standard regression and dynamic ordinary least square (DOLS) models have also found similar results. Dumitrescu-Hurlin test has found the bidirectional causality of cereal production with temperature and CO 2 emissions. Also, unidirectional causality is running from rainfall and rural population to cereal production. The adverse effects of temperature on cereal production are likely to pose severe implications for food security. The paper recommends that governments of the sample countries should research and develop heat-resistant varieties of cereal crops to cope with the adverse effects of temperature on cereal production and ensure food security. | Impact of climate change on cereal production: evidence from lower-middle-income countries | 10.1007/s11356-021-14373-9 |
2021-10-01 | During development, the heart begins pumping as a valveless multilayered tube capable of driving blood flow throughout the embryonic vasculature. The mechanical properties and how they interface with pumping function are not well-defined at this stage. Here, we evaluate pumping patterns using a fluid–structure interaction computational model, combined with experimental data and an energetic analysis to investigate myocardial mechanical properties. Through this work, we propose that a myocardium modeled as a Neo-Hookean material with a material constant on the order of 10 kPa is necessary for the heart tube to function with an optimal pressure and cardiac output. | Valveless pumping behavior of the simulated embryonic heart tube as a function of contractile patterns and myocardial stiffness | 10.1007/s10237-021-01489-7 |
2021-10-01 | Physical activity raises body temperature. However, the literature does not contain studies about whether the employment of hotobiomodulation (PMB) could significantly influence body temperature during a muscle fatigue (MF) protocol. Thus, the aim of this study was to evaluate the effects of PMB on the temperature of the biceps brachii muscle during the performance of a muscle fatigue protocol. The study consisted of 14 volunteers who were divided into two groups (placebo group and laser group) and all individuals rotated into all groups (crossover study). To induce muscle fatigue, three maximum voluntary isometric contractions (MVIC) were performed for 50 s with a 50-s interval. During the MVIC, the muscle strength was assessed using surface electromyography and infrared temperature at 0, 5, 10, and 15 min after the tests. The laser group presented a less accentuated decrease in muscle strength, evidencing a lower rate of muscle fatigue ( p > 0.05) in relation to the other groups. In the temperature analysis, the control group exhibited the highest average temperature, with a significant difference only for the placebo. The results indicate that the control displayed the greatest physical degeneration and the PMB group had a positive effect on MF attenuation and body thermoregulation. | The influence of photobiomodulation on the temperature of the brachial biceps during muscle fatigue protocol | 10.1007/s10103-021-03360-8 |
2021-10-01 | This study evaluated the effect of biopolishing using cellulase enzymes on the low stress mechanical properties, microstructure, and dye uptake of different cellulosic fabrics (cotton, modal, and cotton denim). The tactile features were studied via the Kawabata evaluation system (KES) and showed increments in tensile elongation, tensile resilience and surface properties leading to wearing comfort, whereas the enhanced shear and bending properties of yarns in the fabrics became stronger and more rigid. The surface morphology of the cellulosic fabrics was evaluated by scanning electron microscopy (SEM), and the results indicated that the surface of the treated fabrics became smooth and polished. Biotreatment enhanced comfort, luster, and smoothness without affecting other important properties of the fabrics. The effect of biopolishing before and after the dyeing process has been studied. This was the first study to compare cotton, modal, and denim fabrics for the evaluation of low-stress mechanical properties by employing biopolishing. | Biopolishing of Cellulosic Fabrics: A Study on Low-Stress Mechanical Properties, Microstructure, and Dye Uptake | 10.1007/s12221-021-0356-8 |
2021-10-01 | Abscisic acid (ABA) plays an important role in the adaptive response to environmental stress. The rate-limiting step of ABA biosynthesis is the oxidative cleavage of cis-epoxide carotenoid catalyzed by 9-cis-epoxycarotenoid dioxygenase (NCED). In this study, the ORF sequence of RiNCED1 in raspberry fruit was isolated to study the function of this gene under abiotic stress. While RiNCED1 was induced by cold, high salinity, heat, and ABA, it highly expressed in new leaves using quantitative real-time PCR. The overexpression of RiNCED1 in Arabidopsis improved the content of ABA in transgenic plants both in high salt and cold conditions. This indicated that overexpressing of RiNCED1 increased the content of ABA in Arabidopsis , which proved that RiNCED1 was involved in ABA biosynthesis. Furthermore, overexpressing of RiNCED1 lead to higher chlorophyll content, higher proline content; higher peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD) activities; and lower malondialdehyde (MDA) content under high salt and cold stress. These results indicated that overexpression of RiNCED1 increased the resistance to high salt and low temperature in Arabidopsis . This study provided gene resources for breeding Rubus idaeus L. even other stress-tolerant fruit trees. | Raspberry (Rubus idaeus L.) NCED1 gene enhances high salinity and cold tolerance in Arabidopsis | 10.1007/s11627-021-10230-z |
2021-10-01 | The paper studies fatigue and fracture behavior of aluminum alloy AA 7085. Fatigue crack growth, low cycle fatigue (LCF), and High cycle fatigue tests have been performed at room temperature. Material’s performance against the crack growth has been evaluated at load ratio of 0.1 and 0.3, parameters that govern crack growth are calculated using Paris and Walker model. XFEM has been used for the simulation of fatigue crack growth. Heaviside function is used for the modeling of crack surface while crack front is modeled by branch enrichment function. The simulation result presents a good match with experimental results. In LCF, cyclic softening was observed at higher strain amplitude. Fractographic features of the fracture surfaces obtained from the tests are examined by scanning electron microscopy. | Investigations of Fatigue and Fracture Behavior of AA 7085 | 10.1007/s11665-021-05914-x |
2021-10-01 | How to monitor and identify fracture initiation and propagation is a significant work for the laboratory experiment studies of hydraulic fracturing. In this paper, four main monitoring methods are reviewed and compared through the tri-axial fracturing experiments with natural shale outcrops, including tracer labeling, acoustic emission (AE) monitoring, computerized tomography (CT) scanning and visual fracturing method. Results show that for tracer labeling, fluorescent tracer could visually monitor the hydraulic fracture distribution morphologies, but it has a poor compatibility with slippery water. For the method of AE monitoring, dynamic three dimensional (3D) hydraulic fracture propagation process can be monitored by fixing AE sensors on specimen surfaces. However, the AE signal might display inconsistency with fracture path, which is affected by shale heterogeneity, natural fractures and bedding planes. For the method of CT scanning, many internal rock features can be well recognized, including the location of primary and activated fractures, fracture scales and the interactions between hydraulic fracture and natural fractures. However, CT scanning method cannot identify some micron-and nanoscale fractures characteristics. For the method of visual fracturing, the injected low-temperature metal can extract the fractures skeleton and measure fracture morphologies precisely, but temperature have a significant impact on experiment results. Therefore, combinations of multiple monitoring methods are recommended in laboratory experiment studies. For example, the combination of AE monitoring and CT scanning can effectively identify the propagation behavior of complex fracture network. | Observation of Hydraulic Fracture Morphology for Laboratory Experiments by Using Multiple Methods | 10.1007/s10706-021-01808-w |
2021-10-01 | Process mineralogy of low-grade laterite nickel ore in Indonesia was systematically characterized and the beneficiation process of mineral components such as limonite, serpentine and chromite was studied on the basis of process mineralogy. The results show that the low-grade laterite nickel ore is a typical weathering sedimentary metamorphic oxidized ore, with the main valuable elements of Ni, Co and Cr and the main mineral components of limonite, serpentine, chromite, etc. There is no independent carrier mineral of Ni and Co in the raw ore, and the occurrence states of Ni and Co are relatively dispersed. For the limonite in laterite nickel mine, the nickel bearing magnetite concentrate with nickel grade of 1.98% and recovery rate of 88.42% can be obtained by reduction roasting magnetic separation process. For the serpentine in laterite nickel mine, the cobalt bearing concentrate with Co grade of 0.17% and recovery rate of 23.17% can be obtained by positive and reverse flotation process. A chromium concentrate containing 35.17% Cr 2 O 3 and a recovery of 33.42% can be obtained by using the combined process of coarse and fine classification and gravity and magnetic. 对印尼低品位红土镍矿进行了系统的工艺矿物学表征, 并在工艺矿物学表征的基础上对褐铁 矿、蛇纹石和铬铁矿等矿物组分进行可选性研究. 结果表明, 该低品位红土镍矿属于典型的风化沉积 变质型氧化矿, 主要有价成分为Ni、Co 和Cr, 主要矿物组成为褐铁矿、蛇纹石、铬铁矿等, 未见有 Ni 和Co的独立载体矿物. Ni 和Co赋存状态较为分散, 通过选矿方法来富集Ni 和Co难度较大; Cr 则 主要赋存于铬铁矿中, 可以通过选矿方法来富集Cr; 高温可以促进褐铁矿向磁铁矿的转变. 针对红土 镍矿中的褐铁矿采用还原焙烧磁选工艺可以获得含镍品位1.98%, 回收率88.42%的含镍磁选精矿; 针 对红土镍矿中的蛇纹石采用先正后反的浮选工艺可获得含钴品位0.17%, 回收率为23.17%的含钴精 矿; 针对红土镍矿中的铬铁矿采用粗细分级-重磁联合工艺可获得含Cr 2 O 3 品位为35.17%、回收率为 33.42%的铬精矿. | Relationship between process mineralogical characterization and beneficiability of low-grade laterite nickel ore | 10.1007/s11771-021-4794-7 |
2021-10-01 | Abstract Biodegradable compositions based on low-density polyethylene and polylactide containing arabinogalactan are obtained. Their mechanical properties are studied. It is shown that the development of absorbents based on arabinogalactan is complicated by specific features of the structure of its macromolecules, and possible methods of for overcoming them are considered. | Polymer Composite Materials and Gels with Arabinogalactan | 10.1134/S1995421221040171 |
2021-10-01 | In this paper, we study the physical properties and decoherence of strong coupling magneto-bipolaron qubit in a quantum dot under the effect of an external electric field. The magneto-bipolaron energies of ground and first excited states are evaluated using the Pekar variational method. The decoherence time and entropy are also evaluated. All these calculations are intended to show firstly the effect of both the magnetic and the electric fields on the quasi-particles’ properties in the quantum dot. Our results show that all studied quasi-particles properties in the quantum dot are closely influenced by magnetic and electric fields. The decoherence time increases with increasing of the electric field strength, and decreases with increasing of the magnetic field strength and the electron–phonon coupling constant. From our analysis, it is obvious to see that the application of electric field and magnetic field have opposite effects on the qubit. Comparing both fields, the electric field is advantageous for qubit survival and information storage, while the magnetic field is detrimental to qubit survival and information storage, respectively. The entropy increases with increasing of the electric field strength, and decreases with increasing of the magnetic field strength. We also observe that in the absence of magnetic and electric fields, the entropy varies very slightly with the increase of the confinement strength. We can deduce that, these external fields can help us to modulate the period of information transfer in the system, and hence can be used to control its coherence. | Decoherence of Magneto-Bipolaron with Strong Coupling in a Quantum Dot Qubit Under Applied Electric Field | 10.1007/s10909-021-02612-9 |
2021-10-01 | 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) is widely used as a crosslinker for fluorescence labeling of protein in the fields of biochemistry and food analysis. Many natural polysaccharides often contain some proteins or peptides that are very low in content but play a vital role in their biological function as well as technical applications. Determination of these low-content proteinaceous matters requires a highly sensitive and selective method. In this study, a methodological approach for investigations of the presence of proteinaceous material over the molar mass distribution ( MD ) of polysaccharides was developed using gum acacia (GA) as a model polysaccharide. EDC fluorescence-labeling method was modified by changing the pH (7, 9, and 11) of the solution for the analysis of low-content protein in food materials. Fluorescence spectroscopy and asymmetrical flow field-flow fractionation (AF4) were employed for characterizing the labeling efficiency and physiochemical properties of unlabeled and fluorescence-labeled GA. AF4 provided molar mass ( M ) and the radius of gyration ( r G ) of arabinogalactan (AG) and arabinogalactan protein complex (AGP) and determined the presence of proteinaceous matter over the MD . The labeling efficiencies of GA at pH 7, 9, and 11 determined by fluorescence spectroscopy were 56.5, 68.4, and 72.0%, respectively, with an increment of 15.5% when pH was increased from 7 to 11. The modified EDC fluorescence-labeling method allows highly sensitive and selective analysis of low-content proteinaceous matters and their distribution in natural polysaccharides. Graphical abstract | Modification of EDC method for increased labeling efficiency and characterization of low-content protein in gum acacia using asymmetrical flow field-flow fractionation coupled with multiple detectors | 10.1007/s00216-021-03587-y |
2021-10-01 | Design and exploitation of flame retardant polymers with high electrical conductivity are desired for polymer applications in electronics. Herein, a novel phosphorus-nitrogen intumescent flame retardant was synthesized from pentaerythritol octahydrogen tetraphosphate, phenylphosphonyl dichloride, and aniline. Low-density polyethylene was combined with the flame retardant and multi-walled carbon nanotubes to form a nanocomposite material via a ball-milling and hot-pressing method. The electrical conductivity, mechanical properties, thermal performance, and flame retardancy of the composites were investigated using a four-point probe instrument, universal tensile machine, thermogravimetric analysis, and cone calorimeter tests, respectively. It was found that the addition of multi-walled carbon nanotubes can significantly improve the electrical conductivity and mechanical properties of the low-density polyethylene composites. Furthermore, the combination of multi-walled carbon nanotubes and phosphorus–nitrogen flame retardant remarkably enhances the flame retardancy of matrixes with an observed decrease of the peak heat release rate and total heat release of 49.8% and 51.9%, respectively. This study provides a new and effective methodology to substantially enhance the electrical conductivity and flame retardancy of polymers with an attractive prospect for polymer applications in electrical equipment. | A low-density polyethylene composite with phosphorus-nitrogen based flame retardant and multi-walled carbon nanotubes for enhanced electrical conductivity and acceptable flame retardancy | 10.1007/s11705-021-2035-0 |
2021-10-01 | The problem of steady-state laminar two-dimensional rarefied gaseous flow by natural convection heat transmission in a partly heated square two-sided wavy cavity with an internal heat generation is numerically studied employing the finite volume procedure. The Boussinesq approximation is adopted to account for buoyancy effects. A favorable comparison for validation purposes with previously published work is obtained. The study is performed with distinct values of the external Rayleigh number (10 4 ≤ Ra E ≤ 10 6 ), Knudsen number (0.01 ≤ Kn ≤ 0.1), inclination angle ( ϕ = 0°, 30°, 60°, and 90°), three non-dimensional heater lengths (L/H = 0.175, 0.35, and 0.52), while the Prandtl number (Pr) is fixed at 0.7. The outcomes of this research yield that the average Nusselt number (Nu avg ) relies inversely on Kn and directly on Ra E . Moreover, it is revealed that increasing L/H value decreases Nu avg values at the lower partially heated cavity wall. Additionally, the study reveals that as the heat generation term ( Q gen ) increases, the Nu avg increases as well. Finally, a correlation between Nu avg and the parameters inspected in this research is suggested. | Numerical analysis of rarefied gaseous flows in a square partially heated two-sided wavy cavity with internal heat generation | 10.1007/s10973-020-09959-3 |
2021-10-01 | Abstract Highly conductive carbon-based thin films have been produced by low-energy electron irradiation. Low-energy electron irradiation at a lower density of electrons eliminates the sp 3 hybridization of the carbon atoms by reducing the chemical groups on the surface. Irradiated carbon-based thin films became highly conductive layers that could be used as electrodes for optoelectronic devices. The electrical conductivity σ reached 3 × 10 4 S/m in the case of samples irradiated at a lower density, with a mean value between 3 × 10 5 S/m and 3.3 × 10 2 S/m for highly crystalline graphite structures. The increasing (002) peak diffraction and decreasing intensity ratio I D / I G in the Raman spectra as well as the decreasing bandgap in photoluminescence measurements demonstrated the reduction of oxygen-induced defects in these thin films. Graphic Abstract | Highly Conductive Carbon-Based Thin Films Produced by Low-Energy Electron Irradiation | 10.1007/s11664-021-09058-5 |
2021-10-01 | This study investigated the effects of environmental variation on fish diversity patterns in two coastal streams in northwestern Ecuador. Specifically, we examined the role of topography, instream conditions (pH, conductivity), and human influence (land-use modifications) on fish species richness, diversity and evenness as well as body size diversity and size evenness. Study region comprised 19 sites sampled bimonthly during the dry and wet seasons in 2016–2017. The results showed that the contribution of each measure of fish diversity responded differently to the local drivers. For size-based metrics, fish assemblages displayed greater size diversity (more diversity of body sizes) at lower pH and conductivity levels. Taxonomic metrics showed a negative relationship between the number of species and the downstream–upstream gradient. In both measures of diversity, human influence negatively affected size evenness and Shannon diversity, with less equitable abundance distribution and fewer species in more human-altered locations. These results improve our understanding of how assembly processes operate in shaping local fish assemblages in Neotropical coastal streams. | The response of fish size and species diversity to environmental gradients in two Neotropical coastal streams | 10.1007/s10750-021-04654-2 |
2021-10-01 | Low-emission zones (LEZs) have been implemented widely in Europe to tackle air pollution sourced from vehicular emissions. We quantify the effectiveness of the world's largest LEZ—London's LEZ—in reducing its target pollutant, PM10. Using a difference-in-difference (DID) framework, we find that the least stringent phase I of London's LEZ induced a short-term increase in the roadside PM10 within the zone by about 14.8%, whereas the longer and more restrictive phase II significantly drove down the PM10 by 5.5%. We explore the underlying reasons behind the disparity in policy effect across stages. We show that upon the introduction of phase I, the traffic volume of targeted heavy goods vehicles (HGVs) and temporarily exempted light goods vehicles (LGVs) has substantially increased, outweighing the environmental effect of a higher proportion of greener vehicles. We provide possible behavioral explanations for this phenomenon. | Air pollution and urban road transport: evidence from the world’s largest low-emission zone in London | 10.1007/s10018-021-00307-9 |
2021-10-01 | These days, biomass-based low viscous renewable biofuel is very much popular for internal combustion engine applications due to its unique features compared to other form of biofuels. In this present work, a comparative analysis has been carried out to investigate the suitability of waste biomass-based low viscous biofuel through long-term durability study. A 256 h of long-term endurance test as per Indian Standard: 10,000, Part IX-1980 standard has been conducted using 10% and 20% by volume of waste biomass-based biofuel in two different phases, and the tested results are compared with the results of conventional diesel fuel. During this long-term endurance study, the variations in performance, emissions and behaviours are observed before and after the 256 h of operation in both the phases. The long-term endurance test has degraded the engine components which has reflected in engine performance. The carbon deposit would play a vital role in lowering the engine performance. It has been evident that lubricant oil degradation is deteriorates the engine performance. Furthermore, the durability study has also reflected that the diesel engine emissions are extremely higher after the endurance test when compared to fresh engine. On the other hand, the carbon monoxide and unburned hydrocarbon emissions are lower in waste biomass-based biofuel operation except oxides of nitrogen emissions. This is due to the clean burning ability of biofuel which has shown remarkable combustion behaviour compared to diesel fuel. The long-term tribological test has shown that the kinematic viscosity and flash point of lubricating oil are reduced during endurance study and this has reflected more severe for diesel fuel when compared to waste biomass-based biofuel. The ash content for 20% of lemon peel oil is 19% higher than diesel fuel and 10% of lemon peel oil blend. Higher rate of oxidation has resulted in significant reduction in total base number of lubricating oil which reveals that the low viscous biofuel has higher lube oil degradation. It is also evident that wear of engine components is deteriorated the life of the engine along with lubricant oil degradation. Piston rings wear is more in the lubricant collected from 20% of lemon peel oil blend as compared other fuels. Finally, it has been concluded that the low viscous biofuel has poor resistance on diesel engine wear and this could be rectified before its application. Graphic abstract | Investigations on compression ignition engine durability through long-term endurance study using low viscous biofuel blends | 10.1007/s10098-021-02160-6 |
2021-10-01 | The risk of foodborne illnesses caused by pathogens could be increased in fresh-cut fruit products owing to contamination during processing. Therefore, this study was conducted to investigate the microbiological quality and safety of commercial fresh-cut fruit products in Korea. Additionally, the growth of Listeria monocytogenes in selected fresh-cut fruits was evaluated, and their growth curves were analyzed using predictive growth modeling. The mean count of total aerobic bacteria, coliforms, and yeast/mold was 3.67±1.73 log 10 CFU/g, 1.54±1.01 log 10 CFU/g, and 3.81±1.51 log 10 CFU/g, respectively. Escherichia coli, Staphylococcus aureus, Escherichia coli O157:H7, L. monocytogenes , Salmonella spp., and Cyclospora spp. were not detected in any of the tested samples. Only Bacillus cereus was detected in a few samples at the mean level of 1.72±0.13 log 10 CFU/g. The growth of L. monocytogenes varied depending on the type of fruit; they grew well in non-acidic fresh-cut fruit products during storage at 10 °C. | Evaluation of microbiological quality and safety of fresh-cut fruit products at retail levels in Korea | 10.1007/s10068-021-00974-0 |
2021-10-01 | Satellite communication plays a vital role in extending 5G cellular networks to hard-to-reach areas, including airplanes, railways, shipments, other transport mechanisms, and especially in rural regions of the country that are traditionally beyond the reach of cellular service providers. The devices, specifically those incorporating static memories, being employed for satellite communication, face the challenge of getting prone to cosmic radiations or alpha particle strikes. These strikes cause multi-bit errors in static-memory cells that lead to loss of total output yield. This work proposes a low power twelve transistor (12T) SRAM cell that confirms a reduction in multi-bit errors for the Internet of things based devices supporting fifth-generation (5G) communication system. The proposed SRAM ensures improved read and write ability by utilizing a read decoupled access path and loop cutting mechanism, respectively. The proposed design improves read/write stability by 2.02 $$\times$$ × /1.05 $$\,\times$$ × in comparison to conventional 6T cell with 2.52 $$\times$$ × silicon space overhead. The area overhead is neutralized by 3.17 $$\times$$ × improvement in $$I_{on}$$ I on / $$I_{off}$$ I off ratio that improves cell density of SRAM cell. The improved critical charge of the proposed 12T SRAM cell is compared with four other considered cells to ensure the reduction in multi-bit soft errors, and thereby confirming its suitability for devices supporting satellite communications. The proposed design successfully eliminates the half-select issue that enables the implementation of the bit-interleaved architecture. The leakage power of the proposed 12T cell is improved by 2.65 $$\times$$ × in comparison to conventional 6T attributed to series-connected devices used as loop cutting pair. This reduction of leakage power remains sustained till 110 $$^{\circ }$$ ∘ temperature. The simulation of this work has been conducted with cadence virtuoso tool using GPDK 45 nm technology file. | A Multi-bit Error Upset Immune 12T SRAM Cell for 5G Satellite Communications | 10.1007/s11277-021-08462-8 |
2021-10-01 | Three trials were conducted to evaluate the performances of red snapper, Lutjanus campechanus , in low salinities. The median lethal concentration (96 h LC50) of salinity was determined by trimmed Spearman-Karber method using survival data of fish (18.9 ± 0.2 g) collected after 96 h from acclimation to 2, 4, 8, and 32 ppt salinities in 800 L tanks ( n = 3), while the serum osmolality of fish (74.1 ± 3.9 g) was determined after 48 h from acclimation to 6, 8, 16, 24, and 32 ppt salinities in 150 L tanks ( n = 3). The growth trial was conducted for 6 weeks in 800 L tanks to determine the growth and survival of fish (18.8 ± 0.2 g) at 8 ppt salinity compared to the control (32 ppt salinity). At the conclusion, the isosmotic point of fish was estimated as 357.2 mmol/kg (correspond to 11.0 ppt salinity), while the 96 h LC50 was estimated as 5.65 ppt salinity. No significant differences were noted for survival and FCR of fish reared in 8 and 32 ppt salinities. However, growth was significantly lower in fish reared in 8 ppt salinity compared to the fish reared in 32 ppt salinity. The reduced growth could be, at least partially, due to the increased osmoregulatory energy expenditure at lower salinities. | Effect of salinity on growth, survival, and serum osmolality of red snapper, Lutjanus campechanus | 10.1007/s10695-021-01009-5 |
2021-10-01 | Objective: Cardiac hypertrophy and fibrosis are major pathological manifestations observed in left ventricular remodeling induced by angiotensin II (AngII). Low-intensity pulsed ultrasound (LIPUS) has been reported to ameliorate cardiac dysfunction and myocardial fibrosis in myocardial infarction (MI) through mechano-transduction and its downstream pathways. In this study, we aimed to investigate whether LIPUS could exert a protective effect by ameliorating AngII-induced cardiac hypertrophy and fibrosis and if so, to further elucidate the underlying molecular mechanisms. Methods: We used AngII to mimic animal and cell culture models of cardiac hypertrophy and fibrosis. LIPUS irradiation was applied in vivo for 20 min every 2 d from one week before mini-pump implantation to four weeks after mini-pump implantation, and in vitro for 20 min on each of two occasions 6 h apart. Cardiac hypertrophy and fibrosis levels were then evaluated by echocardiographic, histopathological, and molecular biological methods. Results: Our results showed that LIPUS could ameliorate left ventricular remodeling in vivo and cardiac fibrosis in vitro by reducing AngII-induced release of inflammatory cytokines, but the protective effects on cardiac hypertrophy were limited in vitro. Given that LIPUS increased the expression of caveolin-1 in response to mechanical stimulation, we inhibited caveolin-1 activity with pyrazolopyrimidine 2 (pp2) in vivo and in vitro. LIPUS-induced downregulation of inflammation was reversed and the anti-fibrotic effects of LIPUS were absent. Conclusions: These results indicated that LIPUS could ameliorate AngII-induced cardiac fibrosis by alleviating inflammation via a caveolin-1-dependent pathway, providing new insights for the development of novel therapeutic apparatus in clinical practice. 目的 心肌肥厚和纤维化是血管紧张素II(AngII)引起的左心室重构的主要病理表现. 既往研究表明低强度脉冲超声(LIPUS)能通过机械传导及其下游途径改善心肌梗死(MI)患者的心功能不全和心肌纤维化. 因此, 本研究旨在探讨LIPUS是否能改善AngII诱导的心肌肥厚和纤维化, 并进一步阐明其潜在分子机制. 创新点 本研究首次发现LIPUS能通过机械敏感蛋白——小窝蛋白1(caveolin-1)减轻AngII引起的炎症反应, 从而在体内和体外改善AngII引起的心肌纤维化. 本研究为LIPUS今后在临床上用于预防和改善患者心肌纤维化损伤提供了理论依据. 方法 我们用AngII在体内和体外分别模拟心肌纤维化的动物和细胞模型. 在体内, 从术前1周到术后4周, 每2天用LIPUS照射心前区20分钟;在体外, 每隔6小时照射细胞20分钟, 一共2次. 然后, 用超声心动图、 组织病理学和分子生物学方法评价心肌肥大和纤维化水平. 结论 实验结果表明, LIPUS可通过降低AngII诱导的炎症细胞因子的释放, 从而改善体内左室重构和体外心肌纤维化. 但其对体外心肌肥大的保护作用有限. 在机械刺激下, LIPUS能上调caveolin-1的表达. 而进一步研究发现, 在体内体外利用吡唑吡嘧啶2(pp2)预先抑制caveolin-1的活性后, LIPUS下调炎症反应和改善心肌纤维化的作用被明显逆转. 以上结果表明, LIPUS可以通过caveolin-1依赖的途径减轻炎症, 从而改善AngII诱导的心肌纤维化, 并为这一新型治疗仪器的临床应用提供了新的思路和理论依据. | Low-intensity pulsed ultrasound ameliorates angiotensin II-induced cardiac fibrosis by alleviating inflammation via a caveolin-1-dependent pathway | 10.1631/jzus.B2100130 |
2021-10-01 | Wettability alteration has been recognized as the dominant mechanism of ion-tuned waterflooding, where the ionic composition of injecting brine is modified to improve oil recovery. Yet mechanisms of ion-tuned wettability have not been fully understood, and there are ongoing debates over the effectiveness and relative contribution of each mechanism. In this paper, ion-tuned wettability in variable oil-brine-rock (OBR) systems over a wide range of ionic compositions is theoretically investigated, with focuses on two electrokinetic mechanisms, double layer expansion (DLE) and multicomponent ion exchange (MIE). Results indicate that the qualitative features of ion-tuned wettability in terms of DLE and MIE in various OBR systems with different surface properties can be divided into two typical types, depending on the electrical double layer (EDL) interaction being repulsive or attractive. With attractive EDL force, both DLE and MIE do not contribute to the water-wetness. While with repulsive EDL force, DLE only takes effect at relatively high concentration and MIE has a significantly larger impact at a low percentage of divalent cation. In addition, DLE and MIE can have a synergistic effect, where one mechanism alone has a negligible effect on wettability but two mechanisms combined have a big impact. Wettability alteration in various oil-brine-rock systems share similar features and can be divided into two types. Double layer expansion (DLE) and multicomponent ion exchange (MIE) only take effect at a range of ionic compositions. The contribution of DLE and MIE cannot be simply separated and compared. | Electrokinetic Mechanisms and Synergistic Effect on Ion-Tuned Wettability in Oil-Brine-Rock Systems | 10.1007/s11242-021-01551-z |
2021-10-01 | The study aimed to characterize the dynamics involved in the water quality parameters in a biofloc system (BFT) during the super-intensive cultivation of Litopenaeus vannamei using two levels of artificial brackish water. The test was designed with two salinity levels, T 16 (16‰) and T 8 (8‰), with 4 replicates, and 250 shrimps/m 2 by 60 days, water analysis and animal performance were studied in each treatment. No significant differences were observed between the two salinities for biochemical oxygen demand (BOD 5 ), total chemical oxygen demand (CODt), and fixed suspended solids (FSS). Using CODt/BOD 5 , it was possible to identify the water biodegradability and manage the concentration of organic and inorganic matter in the medium. Filtered chemical oxygen demand (CODf) was used to monitor the dissolved organic matter, which was higher in T 16 . Carbohydrate (molasses) did not control total ammonia reaching in T 8 = 1.16±0.64 mg/L. This organic matter addition reduced the growth of chemoautotrophic nitrifying bacteria and interfered in the nitrogen dynamics. Regarding total solids and suspended solids, there was a significant difference between treatments, except for FSS. Dissolved oxygen (DO) and oxygen saturation (sO2) were significantly different between the treatments. The maintenance of a more neutral pH and greater alkalinity were observed, with significant differences between the treatments throughout the whole cultivation. Regarding the shrimp growth performance, the high salinity presented more weight gain, specific growth rate, feed conversion and final biomass, and lower mortality then lower salinity. These results showed that shrimps presented a higher performance in salinity 16‰. | Dynamics of the water quality parameters in the super-intensive culture of Litopenaeus vannamei in BFT system on artificial brackish water | 10.1007/s10499-021-00734-1 |
2021-10-01 | The reliability of air quality simulations has a strong dependence on the input emissions inventories, which are associated with various sources of uncertainties, particularly in regions undergoing rapid emission changes where inventories can be ‘out of date’ almost as soon as they are compiled. This work provides a new methodology for updating emissions inventories by source sector using air quality ensemble simulations and observations from a dense monitoring network. It is adopted to determine the short-term trends in carbon monoxide (CO) emissions, an important pollutant and precursor to tropospheric ozone, in a study area centred around Beijing following the implementation of clean air policies. We sample the uncertainties associated with using an a priori emissions inventory for the year 2013 in air quality simulations of 2016, using an atmospheric dispersion model combined with a perturbed emissions ensemble (PEE), which is constructed based on expert-elicited uncertainty ranges for individual source sectors in the inventory. By comparing the simulation outputs with observational constraints, we are able to constrain the emissions of key source sectors relative to those in the a priori emissions inventory. From 2013 to 2016, we find a 44–88% reduction in the transport sector emissions (0.92–4.4×10 5 Mg in 2016) and a minimum 61% decrease in residential sector emissions (<3.5×10 5 Mg in 2016) within the study area. We also provide evidence that the night-time fraction of traffic sources in 2016 was higher than that in the 2013 emissions inventory. This study shows the applicability of PEEs and high-resolution observations in providing timely updates of emission estimates by source sector. | Constraining emission estimates of carbon monoxide using a perturbed emissions ensemble with observations: a focus on Beijing | 10.1007/s11869-021-01041-7 |
2021-10-01 | Phosphorus is an important macronutrient for plant growth and is acquired by plants mainly as phosphate. Phosphate fertilizer is usually used to reduce inorganic phosphate (Pi) deficiency in the soil, improve the low phosphorus and drought tolerance of plants, and promote plant growth. Phosphate transporters (PHTs) play an important role in absorbing phosphorus from the soil. MdPHT1;7 was induced by Pi deficiency and drought in roots in our previous research. In this study, we cloned MdPHT1;7 and showed its heterologous expression can complement a high-affinity Pi transporter gene in the Pi uptake-defective yeast mutant BY4743. MdPHT1;7 is a phosphorus transporter located on the cell membrane. Overexpression of MdPHT1;7 in ‘Orin’ apple and ‘Micro-Tom’ tomato enhanced Pi accumulation, low Pi tolerance and drought tolerance. We hypothesized that MdPHT1;7 can enhance Pi absorption and play an important role in improving plant resistance to low phosphorus and drought stresses. | Phosphate Transporter MdPHT1;7 Enhances Phosphorus Accumulation and Improves Low Phosphorus and Drought Tolerance | 10.1007/s12374-021-09309-2 |
2021-10-01 | Low salinity water flooding (LSWF) has been recognized as one of the promising methods for enhanced oil recovery (EOR) in sandstone reservoirs. Both the positive response to LSWF in terms of additional oil recovery and the negative effect of severe permeability impairment due to fines migration have been reported. Therefore, screening of the EOR methods in clay-rich sandstone rocks is required to obtain an optimum EOR design. We examined the effect of kaolinite clay on oil recovery and fines migration due to reducing the injected water salinity using glass micromodels functionalized with clay minerals. Experiments were conducted with both clean (clay-free) and clay-coated porous media using polar (crude oil) and nonpolar oil samples in the presence of connate water. The salinity of the displacing fluid was decreased stepwise in the following order: 30,000 ppm, 4000 ppm, 2000 ppm, and deionized water. Incremental oil recovery was observed for both clay-coated and clay-free systems, polar and nonpolar oil samples in tertiary mode. The redistribution of oil saturation during LSWF in the clay-coated micromodel was more significant compared to that of clay-free micromodel. Image analysis was used to calculate oil recovery and detect fines migration. In addition, single-phase LSWF was performed to evaluate possible fines migration compared to the two-phase flow experiments. Fines migration was observed during both single- and two-phase flow experiments. Low salinity water injection resulted in higher incremental oil recovery from a clay-coated porous media saturated with nonpolar oil compared to a polar crude oil. | Experimental Study of the Effect of Clay and Oil Polarity on Oil Recovery by Low Salinity Water Flooding Using Glass Micromodel | 10.1007/s11053-021-09877-7 |
2021-10-01 | To determine whether the effects of photobiomodulation (PBM) were associated with the use of Simvastatin in the functional recovery from sciatic nerve in mice submitted to crush injury. Fifty Swiss mice (approximately 3 months old; average weight 40 g) were randomly divided into six groups: naive, sham, control, PBM (660 nm, 10 J/cm 2 ; 30 mW; 0.6 J per day for 28 days; 0.06 cm 2 ; 16.8 J total and 20 s), Simvastatin (20 mg/kg), and PBM/Simv (association of the two protocols). The sciatic functional index (SFI), thermal heat hyperalgesia, mechanical hyperalgesia, and thermographic evaluation were used as analyses. The evaluations were performed preoperatively and 7, 14, 21, and 28 days after the initial injury analyzed by two-way analysis of variance (ANOVA) for mixed models followed by the Bonferroni post-test. All groups except sham and naive presented an SFI compatible with severe peripheral nerve injury on the 7th day of evaluation. The PBM group presented better results in the SFI analysis ( p < 0.001) on the 21st postoperative day compared to the control group. This benefit was maintained when compared to the Simvastatin ( p < 0.001) and PBM/Simv groups ( p < 0.01). The results of the thermal and mechanical hyperalgesia and thermography analyses were not significant ( p > 0.05). The obtained results showed that PBM alone was more effective compared to Simvastatin alone or PBM combined with Simvastatin for sciatic nerve injury in mice. | Photobiomodulation promotes neural regeneration when compared to simvastatin treatment in a sciatic nerve crush model | 10.1007/s10103-020-03176-y |
2021-10-01 | Low-density polyethylene (LDPE) possesses various applications in several industries owing to its durability, low-cost, and many mechano-thermal properties. Unfortunately, LDPE waste creates an environmental threat. The level of biodegradation of black LDPE sheets with fungi isolated from different landfills sites in Sharqiyah Governorate, Egypt, was evaluated. LDPE sheets, the only source of carbon, along with minimal salt medium were incubated on a rotary shaker at 30 °C and 120 rpm for 16 weeks. Aspergillus carbonarius MH 856457.1 and A. fumigatus MF 276893 confirmed to be good candidates for LDPE biodegradation. A mixed culture of two strains showed the excellent weight loss% of sheets as compared to single isolate. Further efforts to improve the degrading capacity through physical and chemical treatments were performed. The biodegradation was significantly stimulated by 39.1% (thermal treatment), 17.76% (HNO 3 treatment), and 5.79% (Gamma-irradiation treatment). Laccases and manganese peroxidases activities were assayed. LDPE biodegradation was analyzed by scanning electronic microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and gas chromatography–mass spectrometry (GC–MS). FTIR spectra showed the appearance of new functional groups assigned to hydrocarbon biodegradation and confirmed the role of manganese peroxidase in process. The changes in the FTIR spectra of the mixed culture biomass before and after the biodegradation (Δ73 cm −1 ) and the surface changes in the biodegraded LDPE (as indicated from SEM) confirmed the depolymerization of LDPE. From GC–MS analysis, the plasticizers bis(2-ethylhexyl) phthalate, Diisssctyl phthalate, 1,2-benzenedicarboxylic acid diisooctyl ester, and tributyl acetylcitrate completely biodegraded. Moreover, several antioxidants, antimicrobial, and anticancer compounds, and methyl esters of fatty acids were produced. | Biodegradation of low-density polyethylene (LDPE) using the mixed culture of Aspergillus carbonarius and A. fumigates | 10.1007/s10668-021-01258-7 |
2021-10-01 | Abstract Kinetic patterns are found for the destruction of Bisphenol A (BPA) with the participation of highly reactive oxygen-containing radicals generated in situ in an aqueous medium under the action of acoustic cavitation in a megahertz range (1.7 MHz) and low pressure hydrodynamic cavitation (LPHC). It is shown that the considered oxidative systems can be ranked according to the efficiency and rate of destruction of BPA: LPHC/US/Fe 2+ /S 2 O $$_{8}^{{2 - }}$$ > US/Fe 2+ /S 2 O $$_{8}^{{2 - }}$$ > /Fe 2+ /S 2 O $$_{8}^{{2 - }}$$ > LPHC/US/S 2 O $$_{8}^{{2 - }}$$ > LPHC/US > LPHC. It is concluded that a synergistic effect reveals substantial activation of the oxidation of BPA under the combined action of high-frequency ultrasound and LPHC in an LPHC/US/Fe 2+ /S 2 O $$_{8}^{{2 - }}$$ Fenton-like iron–persulfate system. It is found that full conversion of BPA in an LPHC/US/Fe 2+ /S 2 O $$_{8}^{{2 - }}$$ hybrid oxidative system is achieved after 240 min of treatment, and the mineralization of the organic substance is 60%. | Oxidation of Bisphenol A in a Hybrid Oxidative System, Based on the Combined Action of Acoustic and Low-Pressure Hydrodynamic Cavitation | 10.1134/S0036024421100022 |
2021-10-01 | Objectives The aim of this study was to evaluate the combined effects of recombinant human bone morphogenetic protein - 9 (rhBMP-9) loaded onto absorbable collagen sponges (ACS) and low-intensity pulsed ultrasound (LIPUS) on bone formation in rat calvarial defects. Materials and methods Circular calvarial defects were surgically created in 18 Wistar rats, which were divided into LIPUS-applied (+) and LIPUS-non-applied (−) groups. The 36 defects in each group received ACS implantation (ACS group), ACS with rhBMP-9 (rhBMP-9/ACS group), or surgical control (control group), yielding the following six groups: ACS (+/−), rhBMP-9/ACS (+/−), and control (+/−). The LIPUS-applied groups received daily LIPUS exposure starting immediately after surgery. At 4 weeks, animals were sacrificed and their defects were investigated histologically and by microcomputed tomography. Results Postoperative clinical healing was uneventful at all sites. More new bone was observed in the LIPUS-applied groups compared with the LIPUS-non-applied groups. Newly formed bone area (NBA)/total defect area (TA) in the ACS (+) group (46.49 ± 7.56%) was significantly greater than that observed in the ACS (−) (34.31 ± 5.68%) and control (−) (31.13 ± 6.74%) groups ( p < 0.05). The rhBMP-9/ACS (+) group exhibited significantly greater bone volume, NBA, and NBA/TA than the rhBMP-9/ACS (−) group (2.46 ± 0.65 mm 3 vs. 1.76 ± 0.44 mm 3 , 1.25 ± 0.31 mm 2 vs. 0.88 ± 0.22 mm 2 , and 62.80 ± 11.87% vs. 42.66 ± 7.03%, respectively) ( p < 0.05). Furthermore, the rhBMP-9/ ACS (+) group showed the highest level of bone formation among all groups. Conclusion Within their limits, it can be concluded that LIPUS had osteopromotive potential and enhanced rhBMP-9-induced bone formation in calvarial defects of rats. Clinical relevance The use of rhBMP-9 with LIPUS stimulation can be a potential bone regenerative therapy for craniofacial/peri-implant bone defects. | Enhanced bone formation of calvarial bone defects by low-intensity pulsed ultrasound and recombinant human bone morphogenetic protein-9: a preliminary experimental study in rats | 10.1007/s00784-021-03897-6 |
2021-10-01 | Monitoring the concentration of particle pollutants is very important for industrial production control and workers’ health protection. Low-cost sensors are widely used to reduce deployment costs. The outliers in the observed data of pollutant concentration can be eliminated by outlier detection algorithms. However, it is difficult to meet the actual needs of changing working conditions or scene migration in factories by building a single algorithm for specific scenarios. It is a feasible scheme to identify the changing characteristics of data and adaptively adjust the outlier detection algorithm. From the point of view of data characteristics, we creatively match typical data types with high-performance algorithms. The framework proposed in this paper provides a general process including five basic tasks and uses a modular structure to complete the outlier detection target. The actual pollutant data of the workshops are used to evaluate the performance of our framework. At last, we compare eight different strategies under this framework and analyze the contribution of each step to outlier detection from the perspective of algorithm principle. The results show that low-cost sensors following the framework can meet the outlier detection requirements in the field of pollutant monitoring, thus greatly reducing the cost of algorithm selection and data adaptation. | Low-cost sensor outlier detection framework for on-line monitoring of particle pollutants in multiple scenarios | 10.1007/s11356-021-14419-y |
2021-10-01 | The objective of this research was to explore the feasibility of removing ammonium and nitrate in a single electro-bioreactor at low carbon concentration. For that purpose a submerged membrane electro-bioreactor was operated at three influent carbon/nitrogen ratios (3:1, 2:1 and 1:1). For each carbon/nitrogen ratio, a submerged membrane electro-bioreactor and a membrane bioreactor were operated at the same conditions for 60 days. Results showed that the submerged membrane electro-bioreactor successfully removed ammonium and nitrate at all carbon/nitrogen ratios over membrane bioreactor. At carbon/nitrogen ratio of 1:1, the submerged membrane electro-bioreactor exhibited 9%, 55% and 25% higher removal efficiency over membrane bioreactor for ammonium, nitrate and total nitrogen, respectively. At carbon/nitrogen ratio of 3:1, the submerged membrane electro-bioreactor exhibited 0.0%, 89% and 14% higher removal efficiency over membrane bioreactor for ammonium, nitrate and total nitrogen, respectively. Submerged membrane electro-bioreactor system showed its capacity to remove ammonium, nitrate and total nitrogen regardless of carbon/nitrogen ratio. Submerged membrane electro-bioreactor capacity to remove nitrogen components is feasible because the system can be electrically controlled to operate at alternative aerobic/anaerobic conditions. The efficiency of the submerged membrane electro-bioreactor to remove nitrogen components was found to enhance over time, even though carbon is at low concentration, as higher concentrations of anammox bacteria are built up in the system. Beside nitrogen removal, submerged membrane electro-bioreactor showed on average more than 90% removal of orthophosphate. | Enhancement of wastewater nutrient removal at low carbon/nitrogen ratio using a submerged membrane electro-bioreactor | 10.1007/s13762-020-03056-6 |
2021-10-01 | Abstract Low density ionic liquid-based ultrasound-assisted dispersive liquid−liquid microextraction for the preconcentration of aromatic amines in river waters and wastewater before HPLC-UV analysis was studied. In the proposed method, the ionic liquid, trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl) phosphinate, was used as a low density extractant, and ultrasound was used as an efficient dispersing agent. After dispersion, the phases were separated by centrifugation. Next, the low density extractant phase floating on the surface was taken with a microsyringe and was dissolved in a small volume of methanol before chromatographic analysis. The limits of detection were 0.09 ng/mL for 4-toluidine, 0.12 ng/mL for 2,4-dichloroaniline and 0.07 ng/mL for 4-chloroaniline. The accuracy of this method was evaluated by preconcentration and determination of aromatic amines in wastewater and river waters with the recovery values in the range of 81.7–94.9% and precision of 2.8–6.0%. | Low Density Ionic Liquid-Based Ultrasound-Assisted Dispersive Liquid–Liquid Microextraction for the Preconcentration of Trace Aromatic Amines in Waters | 10.1134/S1061934821100130 |
2021-10-01 | This study aimed to evaluate the effect of different photobiomodulation (PBM) radiant exposures on the viability, proliferation, and gene expression of pulp fibroblasts from human primary teeth (HPF) involved in the pulp tissue repair. HPF were irradiated with Laser InGaAlP (Twin Flex Evolution, MMOptics®) at 660-nm wavelength (red); single time, continuous mode, 0.04-cm 2 laser tip area, and 0.225-cm laser tip diameter, keeping the distance of 1 mm between the laser beam and the cell culture. The doses used were between 1.2 and 6.2 J/cm 2 and were evaluated at the 6 h, 12 h, and 24 h after PBM. MTT and crystal violet assays evaluated the cell viability and proliferation. RT-PCR verified VEGF and FGF-2 mRNA expression. A blinded examiner analyzed the data through two-way ANOVA followed by Tukey test ( p < 0.05). The groups with higher powers (10 mW, 15 mW, 20 mW, and 25 mW), shortest application periods (10 s), and radiant exposures between 2.5 and 6.2 J/cm 2 exhibited statistically higher viability than that of the groups with small power (5 mW), longer application period (50 s), and radiant exposure of 6.2 J/cm 2 ( p < 0.05). VEGF and FGF-2 mRNA expression were observed at the three evaluated periods (6 h, 12 h, and 24 h) and the highest expression was in the shortest period ( p < 0.05). All radiant exposures maintained HPF viable. The period of 6 h after irradiation showed statistically greater gene expression for both growth factors than other periods. VEGF mRNA had no differences among the dosimetries studied. The best radiant exposures for FGF-2 gene expression were 2.5 J/cm 2 and 3.7 J/cm 2 . | Could the photobiomodulation therapy induce angiogenic growth factors expression from dental pulp cells? | 10.1007/s10103-021-03291-4 |
2021-10-01 | Low grape quality in early maturing table grape cultivars is a common problem, which reduces production efficiency. Despite the fact that there are numerous measures to be taken, foliar applications of different substances can be commonly used to overcome this low-quality problem in early maturing table grape cultivars. In this research, it was utilized from various doses of biostimulant (BSt) and plant growth regulator (s-abscisic acid, S‑ABA) applications, including Control, BSt 3000 ppm, BSt 4000 ppm, BSt 5000 ppm, S‑ABA 300 ppm, S‑ABA 400 ppm and S‑ABA 500 ppm for improving table grape quality of early maturing cv. Trakya Ilkeren. In the study, various doses of both foliar applications had considerable roles on physical and quality characteristics of cultivar, S‑ABA applications particularly triggered significant increases in total soluble solids content, total phenolic compounds content and total anthocyanin content. As a consequence, it has been highlighted in present study that S‑ABA 400 ppm application provides table grape growers with a tool to increase table grape quality characteristics such as anthocyanins and phenolic compounds in early maturing cv. Trakya Ilkeren. | Manipulating Anthocyanin Accumulation and Phenolic Compounds Profile of cv. Trakya Ilkeren Table Grape (V. vinifera L.) by Using Foliar Biostimulant and Abscisic Acid Applications | 10.1007/s10341-021-00575-5 |
2021-10-01 | Hyaluronic acid (HA)-CD44 pathway showed association with several malignancies. The natural polyphenols Plumbagin, Pongapin and Karanjin showed anti-cancer activities in different tumors including cervical carcinoma. To understand their mechanism of anti-cancer activity, the effect of the compounds on HA-CD44 pathway was analyzed in cervical cancer cell line HeLa. The mRNA expression of three different isoforms of CD44 i.e., CD44s, CD44v3, and CD44v6, was differentially downregulated by the compounds. This was validated by Western blot and immunocytochemical analysis of CD44s.The low molecular weight HA (LMW-HA) showed growth promoting activity in HeLa at low concentration, whereas high molecular weight HA (HMW-HA) had no such effect. The compounds could preferentially downregulate the LMW-HA level in HeLa, as evident in the cell as well as in the cell-free conditioned medium. Concentration-dependent upregulation of HA synthase-2 (HAS2) was seen in the cell by the compounds, whereas differential downregulation of hyalurinidases 1–4 (HYAL 1–4), predominantly HYAL1, were seen. The compounds could also downregulate the downstream target of the pathway p-AKT (T-308) in concentration-dependent manner. Thus, the compounds could attenuate the HA-CD44 pathway in HeLa cell to restrict the tumor growth. | Downregulation of Hyaluronic acid-CD44 signaling pathway in cervical cancer cell by natural polyphenols Plumbagin, Pongapin and Karanjin | 10.1007/s11010-021-04195-1 |
2021-10-01 | Exploiting the prior information is fundamental for image reconstruction in computational hyperspectral imaging (CHI). Existing methods usually unfold the 3D signal as a 1D vector and then handle the prior information among different dimensions in an indiscriminative manner, which inevitably ignores the high-dimensionality nature of the hyperspectral image (HSI) and thus results in poor reconstruction performance. In this paper, we propose a high-order tensor optimization based reconstruction method to boost the quality of CHI. Specifically, we first propose an adaptive dimension-discriminative low-rank tensor recovery (ADLTR) model to exploit the high-dimensionality prior of HSI faithfully. In the ADLTR model, we utilize the 3D tensors as the basic elements to fundamentally preserve the structure information in the spatial and spectral dimensions, introduce a dimension-discriminative low-rankness model to fully characterize the prior in the basic elements, and propose a weight estimation strategy by adaptively exploiting the diversity in each dimension. Then, we develop an optimization framework for the CHI reconstruction by integrating the structure prior in ADLTR with the system imaging principle, which is finally solved via the alternating minimization scheme. Extensive experiments on both synthetic and real data demonstrate that our method outperforms state-of-the-art methods. | Adaptive Dimension-Discriminative Low-Rank Tensor Recovery for Computational Hyperspectral Imaging | 10.1007/s11263-021-01481-9 |
2021-10-01 | In this work, the electrochemical determination of antioxidant compounds in green coffee beans using a low-pressure chromatographic system based on a single 1-cm length monolithic column is presented. Screening of the antioxidant compounds in green coffee beans using this approach was performed under different elution conditions, considering different supporting electrolyte media and applied potential values at detection. Mass spectra analyses for the structure elucidation of the separated compounds are presented. Under the selected experimental conditions, five chlorogenic acids (3-, 4-, 5-, cis- 5-caffeoylquinic acids, and 5-feruloylquinic acid) and caffeine were identified. Resolution values higher than 1.5 were achieved for all identified compounds. The limits of detection for 5-caffeoylquinic acid and caffeine were 9.25 µmol L −1 and 6.73 µmol L −1 , respectively. Acetonitrile consumption was of 0.325 mL per analysis. The figures of merit obtained plus the simplicity of the analytical system assembling and handling highlight the high competitiveness of the presented low-cost approach to be used in substitution of HPLC methodologies currently performed to this end, and for further analytical applications in complex matrices. | Screening of Antioxidant Compounds in Green Coffee by Low-Pressure Chromatography with Amperometric Detection | 10.1007/s12161-021-02037-w |
2021-10-01 | Abstract— The antioxidant effect of dinitrosyl iron complexes (DNICs) was studied in various model systems. DNICs with glutathione ligand (DNIC-GS) effectively inhibited Cu 2+ -induced peroxidation of low density lipoproteins (LDL). The antioxidant effect of DNICs with phosphate ligands and free reduced glutathione (GSH) was less pronounced. In addition, DNIC-GS suppressed reactive oxygen species (ROS) formation during co-oxidation of lecithin liposomes and glucose. Free radical oxidation in this system was induced with a lipophilic azo initiator (AIBN) and evaluated by luminol-dependent chemiluminescence. NO sharply stimulated chemiluminescence during co-oxidation of glucose and liposomes, thus suggesting the formation of potent oxidants under these conditions. DNIC-GS scavenged the superoxide radical anion generated in the xanthine-xanthine oxidase system. Superoxide production was assessed by lucigenin-dependent chemiluminescence and electron paramagnetic resonance (EPR) spectroscopy. Chemiluminescence revealed the dose-dependent mode of the antiradical effect DNIC-GS; moreover, these complexes were more efficient than GSH. EPR spectra of adducts of the DEPMPO spin trap with free radicals suggest that the interaction of DNIC-GS and superoxide does not result in the formation of the thiyl radical of glutathione. Here we propose a mechanism of the antioxidant action of DNIC-GS, suggesting that unstable intermediate complexes are formed upon their interaction with superoxide or lipid radicals. After subsequent intramolecular rearrangement, these intermediates decompose without the free radical formation as the by-products. | A Possible Mechanism of the Antioxidant Action of Dinitrosyl Iron Complexes | 10.1134/S1990750821040090 |
2021-10-01 | Although there are numerous studies of firefly mating flashes, lantern bioluminescence, and anti-predation lucibufagin metabolites, almost nothing is known about their microbiome. We therefore used 16S rRNA community amplicon sequencing to characterize the gut and body microbiomes of four North American firefly taxa: Ellychnia corrusca , the Photuris versicolor species complex, Pyractomena borealis , and Pyropyga decipiens . These firefly microbiomes all have very low species diversity, often dominated by a single species, and each firefly type has a characteristic microbiome. Although the microbiomes of male and female fireflies did not differ from each other, Ph. versicolor gut and body microbiomes did, with their gut microbiomes being enriched in Pseudomonas and Acinetobacter . Ellychnia corrusca egg and adult microbiomes were unique except for a single egg microbiome that shared a community type with E . corrusca adults, which could suggest microbial transmission from mother to offspring. Mollicutes that had been previously isolated from fireflies were common in our firefly microbiomes. These results set the stage for further research concerning the function and transmission of these bacterial symbionts. | North American Fireflies Host Low Bacterial Diversity | 10.1007/s00248-021-01718-7 |
2021-10-01 | Rapid diagnosis of microorganisms and antibiotic resistance is vital for the appropriate treatment of patients with lower respiratory infections, especially for patients in Intensive Care Unit. We conducted a multicenter prospective study to evaluate the ability of the Unyvero pneumonia system for rapid detection from bronchoalveolar lavage fluid (BALF) in China. Eighty-four patients with lower respiratory infections were enrolled, and their BALF samples were collected, and Unyvero, a rapid molecular diagnostic sample-to-answer solution based on multiple PCRs, was applied to detect 21 types of pathogens and 19 types of resistance markers, compared to a routine bacterial culture method. The overall concordance of Unyvero and routine culture was 69/84 (82.1%). Unyvero detected more microorganisms than routine culture (38.1% vs 27.4%, P <0.05) and reported multi-pathogens in more patients than routine culture (10.7% vs 2.4%, P =0.01). The overall sensitivity and specificity of Unyvero for bacteria detection were 84.0% and 98.0%. Besides, Unyvero showed a good performance for antibiotic-resistant bacteria, except Pseudomonas aeruginosa . The concordance was 87.5–100% for methicillin-resistant Staphylococcus aureus and carbapenem-resistant isolates but was only 20–33.3% for Pseudomonas aeruginosa . The high-level semi-quantitative signal intensity of microorganisms detected positive by Unyvero correlates well with positive bacterial cultures. For specimens that were exposed to antibiotic treatment, the Unyvero pneumonia system showed a high concordance with routine bacterial culture and performs well for the detection of antibiotic-resistant bacteria, especially, carbapenem-resistant Klebsiella pneumoniae . It shows promise in guiding the clinical use of antibiotics, such as ceftazidime/avibactam. However, the system needs improvement in detecting resistance markers of Pseudomonas aeruginosa. | An evaluation of the Unyvero pneumonia system for rapid detection of microorganisms and resistance markers of lower respiratory infections—a multicenter prospective study on ICU patients | 10.1007/s10096-021-04259-6 |
2021-09-30 | Low temperature (LT) causes significant yield losses in chickpea ( Cicer arietinum L.). The sucrose starch metabolism is associated with abiotic-stress tolerance or sensitivity in plants. The changes in sugars and starch contents under LT in chickpea have already been studied, however, no information is available on LT-induced alterations in transcription of carbohydrate metabolic pathway genes in chickpea. To understand the differences in the regulation of sucrose and starch metabolism under LT, the expression of sucrose and starch metabolism genes was studied in leaves of cold-sensitive (GPF2) and cold-tolerant (ICC 16349) chickpea genotypes. The mRNA sequences of chickpea genes were retrieved from the public databases followed by confirmation of identity and characterization. All the genes were functional in chickpea. Between the two paralogues of cell wall invertase, cell wall invertase 3×2 ( CWINx2 ) was the truncated version of cell wall invertase 3×1 ( CWINx1 ) with the loss of 241 bases in the mRNA and 67 amino acids at N terminal of the protein . Comparison of expression of the genes between control (22°C day / 16°C night) and LT treated (4°C; 72 h) plants revealed that granule bound starch synthase 2 ( GBSS2 ) and β-amylase 3 ( BAM3 ) were upregulated in ICC 16349 whereas sucrose phosphate synthase 2 ( SPS2 ), CWINx1 , CWINx2 and β-amylase 1 ( BAM1 ) were downregulated. In contrast to this, SPS2 , CWINx1 , CWINx2 and BAM1 were upregulated and GBSS2 downregulated in GPF2 under LT. The gene expression data suggested that UGPase , CWINs , GBSS2 and BAM3 are important components of cold-tolerance machinery of chickpea. | Characterization and differential expression of sucrose and starch metabolism genes in contrasting chickpea (Cicer arietinum L.) genotypes under low temperature | 10.1007/s12041-021-01317-y |
2021-09-30 | The Darreh-Zanjir Zn–Pb deposit is the typical epigenetic carbonate-hosted Zn–Pb deposit in Iran. Mineralization occurs as vein fillings and irregular replacement ore bodies consisting of sphalerite and galena, and with pyrite, chalcopyrite, dolomite, barite, and minor quartz and calcite in the Lower Cretaceous carbonate host rock. Textures include breccia, replacement, massive, and vein-veinlet style. Here, we provide research of the ore geology, geochemistry, and ore-forming fluids of the Darreh-Zanjir Zn–Pb deposit. The vein replacement-shaped ore body is located close to a normal fault. The shape and size of the mineralized body suggest that epigenetic dolomites are replacements with sulfide minerals. Dolomitization is the main wall rock alteration style; alteration intensity increases toward the normal fault. Fluid inclusion microthermometry was carried out on hydrothermal dolomite associated with sulfides. Homogenization temperatures of fluid inclusions from this deposit are predominately <200 °C, with salinities of 6.62 to 22.67 wt.% NaCl equiv. The δ 13 C PDB and δ 18 O SMOW values of host limestones and hydrothermal dolomites plot the near-marine carbonate rocks field in a plot of δ 13 C PDB vs. δ 18 O SMOW diagram. It suggests that CO 2 in the hydrothermal fluids mainly originated from marine carbonate rocks. C and O isotopes, along with fluid inclusions, textural, mineralogical, and geochemical data combined with basic features of MVT-type deposits, suggest that this deposit has formed as a result of the migration of basinal fluids coincident with tectonic activity along with ore-controlling structures. Characteristics of the Darreh-Zanjir deposit are compatible with a Mississippian Valley-type (MVT) classification. | Ore-forming processes, O–C isotopes geochemistry, and fluid inclusions in the Darreh-Zanjir fault control MVT-type Zn–Pb deposit: Iran | 10.1007/s12517-021-08469-2 |
2021-09-28 | The reaction of β-hydroxybutenyl radicals with O 2 and subsequent reactions are regarded as crucial steps in the low-temperature oxidation of 1,3-butadiene. However, the reaction network is not complete and previous studies failed to include accurate rate constants. In this study, the reaction network of β-hydroxybutenyl radicals with O 2 is supplemented, as well as the temperature- and pressure-dependent rate constants which are investigated by high-level quantum chemical calculation, combining with the transition state theory (TST), the variational transition state theory (VTST) and Rice–Ramsperger–Kassel–Marcus/master equation method (RRKM/ME). The results of quantum chemical calculations indicate that Waddington reaction is the dominant channel, while the intramolecular addition reactions of the radical center atoms to the double bonds are found to be important non-alkyl-analogue reactions. Moreover, some of the reactions are investigated in the present study as well, whose pressure-dependent kinetics have not been reported so far. The calculations indicate that addition reaction of β-hydroxybutenyl with O 2 is pressure independent when the temperature is below 600 K, while above 600 K, the effect of pressure is increasingly significant. Furthermore, the formation of β-hydroxybutenylperoxy is a dominant channel when the pressure is above 1 atm, while below 0.1 atm, other channels begin to take place with the increase in temperature. | A theoretical study of β-hydroxybutenyl with O2 on the HOC4H6OO· potential energy surface | 10.1007/s00214-021-02842-w |
2021-09-27 | The intention of this discussion is as a simple introduction for general—non-nuclear magnetic resonance (NMR)-specialist—materials scientists, to make them aware as to how some of the materials science measurements that they need to make might possibly be addressed by simple physical measurements using low-cost time-domain NMR apparatus. The intention is to include a minimum of complex NMR detail, while enabling general material-scientists to see that simple easily understood time-domain NMR might be of use to them. That is how I have tried to structure this discussion. It seems to me be generally forgotten how much of materials science is actually physics, as opposed to chemistry, and the extent to which simple time-domain NMR may be used to make measurements of the physical properties of materials. There frequently seems to be an assumption that if NMR is mentioned that it is chemical analysis methods that are under discussion, or possibly magnetic resonance imaging (MRI). These are both extremely powerful techniques, but to forget about the physics that often governs the properties of the sample can be a significant mistake. Key material science properties are often described in different fields using the terms mobility/dynamics/stiffness/viscosity/rigidity of the sample. These properties are usually dependent on atomic and molecular motion in the sample. We will discuss a method, time-domain NMR, that appears often to be ignored, to obtain quantitative or comparative information on these properties. The intention of this paper is not to probe the material properties of some interesting system, but to discuss in as clear a manner as possible a particular technique, “low-field time-domain NMR”, to bring this technique and its advantages to the attention of other material scientists. Thus we discuss time-domain NMR and MRI, as methods of measuring the physical properties of liquid and solid materials. Time-domain NMR is also a good technique for measuring pore-size distributions from the nano-meter to microns, using a technique known as NMR cryoporometry (NMRC). Standard MRI protocols may be combined with NMRC, so that spatial resolution of pore dimensions may also be obtained. Low-field time-domain NMR is, at its fundamentals, a very approachable and easily comparative technique, where the material properties may often be extracted from the time-domain data much more simply than from say high-field high-resolution spectral data. In addition, low-field time-domain NMR apparatus is typically a factor of 10 to 100 times cheaper than high-field high-resolution solid-state NMR systems. | A review of the use of simple time-domain NMR/MRI for material-science | 10.1007/s42452-021-04791-2 |
2021-09-25 | Background Spinal epidural hematomas usually occur under certain conditions; they rarely occur spontaneously. The prevalence of spontaneous spinal epidural hematoma is ~ 0.1 per 100,000, and the male-to-female ratio is approximately 1.4 to 1. Herein, we describe a rare case of spontaneous spinal epidural hematoma. Case presentation A 63-year-old Taiwanese woman, with underlying hypertension, anemia, and a history of cardiovascular accident without sequela, was admitted to our emergency department with a chief complaint of sudden bilateral weakness in the lower limbs. Magnetic resonance imaging revealed a spontaneous epidural hematoma. The patient underwent emergency surgery to remove the epidural hematoma and laminectomy for decompression. The bilateral lower limb weakness was alleviated immediately after the surgery. Conclusion In patients with no risk factors related to spinal epidural hematoma, symptoms of bilateral lower limb weakness must be investigated carefully because this condition may occur spontaneously. | Spontaneous spinal epidural hematoma: a case report | 10.1186/s12245-021-00379-0 |
2021-09-24 | The formulation and implementation of Low-Carbon City Policy (LCCP) is an essential initiative for China to build its low-carbon society. Based on the panel data of 282 prefecture-level cities in China from 2003 to 2016, this study evaluates the effects of LCCP implementation on pilot cities’ carbon emission performance using difference-in-differences method, and then the mechanism has also been examined with a mediating effect model. The results show that: first, the LCCP implementation has increased the carbon emission performance of the pilot cities significantly, indicating that it is an effective way to promote the low-carbon transformation of Chinese cities. Second, the positive effects in CO 2 performance resulting from LCCP demonstrate significant heterogeneity: in general, the cities in east China, with higher economic development level and in a larger size, achieve more significant CO 2 emission reduction than their respective counterparts. The results on the mechanism test imply that the LCCP helps improve pilot cities’ carbon emission performance in three ways, including reducing energy consumption, updating the industrial structure, and promoting technological progress. Finally, some useful policy recommendations are put forward to promote China’s low-carbon city construction. | Evaluating the CO2 abatement effects of low-carbon city policy in China: a quasi-natural experiment | 10.1186/s42162-021-00167-3 |
2021-09-23 | Background Anaemia is a worldwide problem and iron deficiency is the most common cause. In pregnancy, anaemia increases the risk of adverse maternal, foetal and neonatal outcomes. India’s anaemia rate is among the highest in the world with India’s National Family Health Survey indicating over 50% of pregnant women were affected by anaemia. India’s Anaemia Mukt Bharat-Intensified National Iron Plus Initiative aims to reduce the prevalence of anaemia among reproductive-age women, adolescents and children by 3% per year and facilitate the achievement of a Global World Health Assembly 2025 objective to achieve a 50% reduction of anaemia among women of reproductive age. However, preliminary results of the NFHS-5 survey completed in 2020 indicate that anaemia rates are increasing in some states and these targets are unlikely to be achieved. With oral iron being the first-line treatment for iron deficiency anaemia (IDA) in pregnancy, these results are likely to be impacted by the side effects, poor adherence to tablet ingestion and low therapeutic impact of oral iron. These reports suggest a new approach to treating IDA, specifically the importance of single-dose intravenous iron infusions, may be the key to India effectively reaching its targets for anaemia reduction. Methods This 3-arm, randomized controlled trial is powered to report two primary outcomes. The first is to assess whether a single dose of two different intravenous formulations administered early in the second trimester of pregnancy to women with moderate IDA will result in a higher percentage of participants achieving a normal for pregnancy Hb concentration at 30–34 weeks’ gestation or just prior to delivery when compared to participants taking standard doses of oral iron. The second is a clinical outcome of low birth weight (LBW) (< 2500 g), with a hypothesis that the risk of LBW delivery will be lower in the intravenous iron arms when compared to the oral iron arm. Discussion The RAPIDIRON trial will provide evidence to determine if a single-dose intravenous iron infusion is more effective and economically feasible in reducing IDA in pregnancy than the current standard of care. Trial registration Clinical Trials Registry – India CTRI/2020/09/027730. Registered on 10 September 2020, http://ctri.nic.in/Clinicaltrials/showallp.php?mid1=46801&EncHid=&userName=anemia%20in%20pregnancy | RAPIDIRON: Reducing Anaemia in Pregnancy in India—a 3-arm, randomized-controlled trial comparing the effectiveness of oral iron with single-dose intravenous iron in the treatment of iron deficiency anaemia in pregnant women and reducing low birth weight deliveries | 10.1186/s13063-021-05549-2 |
2021-09-23 | Background Meningitis retention syndrome (MRS) is a rare condition that presents with acute urinary retention as a complication of aseptic meningitis. Cases of MRS due to varicella zoster virus (VZV) infection without a rash are rare. We report the case of a patient who had no signs of meningitis or VZV infection, including a rash. Case presentation A 58-year-old man presented with dysesthesia of the lower limbs and acute urinary retention. He had fever but no rash and no signs of meningitis. He was diagnosed to have VZV infection based on the detection of VZV DNA in the cerebrospinal fluid. He responded satisfactorily to a course of intravenous acyclovir and experienced no sequelae during a 2-year follow-up period. Conclusion MRS due to aseptic meningitis of viral origin should be considered in the differential diagnosis of acute urinary retention even in the absence of specific signs and symptoms of meningitis or a suggestive rash. | Meningitis retention syndrome caused by varicella zoster virus in a patient without a rash: a case report | 10.1186/s12879-021-06692-6 |
2021-09-22 | In this paper, a mixed sintering accelerator of colophony and cetyltrimethyl ammonium bromide (CTAB) was developed to improve the sintering properties of Cu nanoparticles (NPs) paste. With the synergy effect of the mixed sintering accelerator, Cu NPs paste could be well sintered at 260 °C for 30 min under a pressure of 2 MPa, and the shear strength was greatly improved from 15 to 33 MPa. The fracture morphology of the Cu NPs joint transformed from brittle interface failure features to ductile dimple features, and the porosity in the sintered layer was significantly reduced. XRD analysis further confirmed that the synergy of colophony and CTAB could effectively remove the oxides in the Cu NPs paste during sintering, and thereby improve the sintering properties. This work can provide an applicable approach to improve the sintering properties of metal NPs and help to understand the synergy effect of sintering accelerators on the bonding behaviors of metal nanoparticles at low temperatures. Graphic abstract | Synergy effect of mixed sintering accelerator on the deoxidation and sintering property improvement of Cu nanoparticles at low temperature | 10.1007/s00339-021-04924-9 |
2021-09-22 | This paper presents some results of the influence of severe plastic deformation on the microstructure evolution, grain refinement aspect, and mechanical properties of ultra-low carbon steel. Ti-stabilized experimental IF steel was deformed at a room temperature with unconventional SPD process—dual rolls equal channel extrusion (DRECE). Mechanical properties and structure of ferritic steel in initial state and after selected steps of deformation were investigated. The mechanical properties were determined by static tensile tests carried out at a room temperature and microhardness research. The structural investigations involved using scanning transmission electron microscopy observations, electron back scattered diffraction and measurements of the crystallographic texture. The DRECE process affects the evolution of the structure. The microstructural investigations revealed that the processed strips exhibited a dislocation cell and grain structures with mostly low angle grain boundaries. The electron backscattering diffraction (EBSD) examination showed that the processed microstructure is homogeneous along the strips thickness. The mechanical properties of the DRECE-processed IF steel strips increased with an increase the number of passes. | The effect of severe plastic deformation on the IF steel properties, evolution of structure and crystallographic texture after dual rolls equal channel extrusion deformation | 10.1007/s43452-021-00303-6 |
2021-09-18 | A neighborhood-restricted mixed Gibbs sampling (MGS)-based approach is proposed for low-complexity high-order modulation large-scale multiple-input multiple-output (LS-MIMO) detection. The proposed LS-MIMO detector applies a neighborhood limitation (NL) on the noisy solution from the MGS at a distance d — thus, named d -simplified MGS ( d -sMGS) — in order to mitigate its impact, which can be harmful when a high-order modulation is considered. Numerical simulation results considering 64-QAM demonstrated that the proposed detection method can substantially improve the MGS algorithm convergence, whereas no extra computational complexity per iteration is required. The proposed d -sMGS-based detector suitable for high-order modulation LS-MIMO further exhibits improved performance × complexity tradeoff when the system loading is high, i.e., when K N ≥ 0.75 $\frac {K}{N}\geq 0.75$ . Also, with increasing the number of dimensions, i.e., increasing number of antennas and/or modulation order, a smaller restriction of 2-sMGS was shown to be a more interesting choice than 1-sMGS. | Mitigating the noisy solution impact of mixed Gibbs sampling detector in high-order modulation large-scale MIMO systems | 10.1186/s13634-021-00725-7 |
2021-09-17 | We consider reduced quantum electrodynamics ( RQED d γ , d e $$ {\mathrm{RQED}}_{d_{\gamma },{d}_e} $$ ) a model describing fermions in a d e -dimensional space-time and interacting via the exchange of massless bosons in d γ -dimensions ( d e ≤ d γ ). We compute the two-loop mass anomalous dimension, γ m , in general RQED 4 , d e $$ {\mathrm{RQED}}_{4,{d}_e} $$ with applications to RQED 4 , 3 and QED 4 . We then proceed on studying dynamical (parity-even) fermion mass generation in RQED 4 , d e $$ {\mathrm{RQED}}_{4,{d}_e} $$ by constructing a fully gauge-invariant gap equation for RQED 4 , d e $$ {\mathrm{RQED}}_{4,{d}_e} $$ with γm as the only input. This equation allows for a straightforward analytic computation of the gauge-invariant critical coupling constant, α c , which is such that a dynamical mass is generated for α r > α c , where α r is the renormalized coupling constant, as well as the gauge-invariant critical number of fermion flavours, N c , which is such that α c → ∞ and a dynamical mass is generated for N < N c . For RQED 4 , 3 , our results are in perfect agreement with the more elaborate analysis based on the resolution of truncated Schwinger-Dyson equations at two-loop order. In the case of QED 4 , our analytical results (that use state of the art five-loop expression for γ m ) are in good quantitative agreement with those obtained from numerical approaches. | Two-loop mass anomalous dimension in reduced quantum electrodynamics and application to dynamical fermion mass generation | 10.1007/JHEP09(2021)107 |
2021-09-17 | Background Transperineal laser ablation (TPLA) of the prostate is a novel, mini-invasive option for men with lower urinary tract symptoms (LUTS) due to benign prostate hyperplasia (BPH). Our aim was to assess the impact of ultrasound-guided TPLA regarding urodynamic improvement and sexual function, monitoring clinical data, postprocedural complications and imaging findings at 3-T multiparametric magnetic resonance imaging. Methods Forty-four patients aged ≥ 50 affected with moderate to severe LUTS (International Prostate Symptoms score ≥ 12) due to benign prostatic obstruction and refractoriness, intolerance or poor compliance to medical therapies underwent US-guided TPLA between May 2018 and February 2020. Clinical measurements included PSA, uroflowmetry, sexual function assessment (using the International Index of Erectile Function and Male Sexual Health Questionnaire-Ejaculatory Dysfunction short form) and quality of life questionnaire. Adverse events were evaluated using the Clavien-Dindo scale. Volume changes were measured by MRI and automatic segmentation software during 1-year follow-up. Registration: NCT04044573 – May 5th, 2018, https://www.clinicaltrials.gov Results MRI assessed the changes over time with a 53% mean reduction of adenoma volume and 71% of the ablated area, associated with clinical and functional improvement and resolution of LUTS in all cases. Five of 44 patients (11.3%) had urinary blockage due to clots and required re-catheterisation for 2 weeks. The overall adverse event rate was 7%. Conclusion US-guided TPLA performed as a safe, manageable and effective treatment for LUTS. It could be considered an alternative effective mini-invasive procedure to standard treatments for BPH in the outpatient setting. | 3-T MRI and clinical validation of ultrasound-guided transperineal laser ablation of benign prostatic hyperplasia | 10.1186/s41747-021-00239-9 |
2021-09-17 | Background Given the large bamboo resource base with considerable potential to act as an important carbon sink, Ethiopia has included bamboo in the national Reducing Emissions from Deforestation and Forest Degradation and enhancing forest carbon stocks (REDD+) and Clean Development Mechanisms (CDM) programs. However, little is known about the carbon stock and sequestration potential of bamboo forests. As a result, this research was conducted to quantify the carbon sequestration and storage capacity of Oxytenanthera abyssinica forests in the Lower Beles River Basin, northwestern Ethiopia. To this end, a total of 54 circular plots, each measuring 100 m 2 with a radius of 5.64 m, were established to conduct the inventory in Assitsa and Eddida bamboo forests, the typical bamboo sites in Lower Beles River Basin. Biomass accumulation of bamboo was estimated using an allometric equation based on diameter at breast height (DBH) and age. Soil samples were taken from two different soil depths (0–15 and 15–30 cm) to determine soil organic carbon. Results Results indicate that the mean biomass of the bamboo forests in the study area accounted for about 177.1 $$\pm$$ ± 3.1 Mg ha −1 . The mean biomass carbon and soil organic carbon stock of the bamboo forests were 83.2 $$\pm$$ ± 1.5 Mg C ha −1 and 70 $$\pm$$ ± 1.7 Mg C ha −1 , respectively. Therefore, the mean carbon stock of the O. abyssinica bamboo forests was 152.5 $$\pm$$ ± 2.5 Mg C ha −1 to 559.8 $$\pm$$ ± 9.0 ton CO 2 ha −1 . Conclusion This study highlights the importance of assessing bamboo’s carbon stock and sequestration potential for enhancing its role in climate change mitigation and sustainable resource management. The O. abyssinica bamboo forests of the study area have significant carbon stock and sequestration potential. Therefore, sustainable management of these crucial vegetation resources will enhance their role in providing ecosystem services, including climate change mitigation. | Biomass, carbon stock and sequestration potential of Oxytenanthera abyssinica forests in Lower Beles River Basin, Northwestern Ethiopia | 10.1186/s13021-021-00192-5 |
2021-09-16 | Background Being able to accurately assess the 3D architecture of plant canopies can allow us to better estimate plant productivity and improve our understanding of underlying plant processes. This is especially true if we can monitor these traits across plant development. Photogrammetry techniques, such as structure from motion, have been shown to provide accurate 3D reconstructions of monocot crop species such as wheat and rice, yet there has been little success reconstructing crop species with smaller leaves and more complex branching architectures, such as chickpea. Results In this work, we developed a low-cost 3D scanner and used an open-source data processing pipeline to assess the 3D structure of individual chickpea plants. The imaging system we developed consists of a user programmable turntable and three cameras that automatically captures 120 images of each plant and offloads these to a computer for processing. The capture process takes 5–10 min for each plant and the majority of the reconstruction process on a Windows PC is automated. Plant height and total plant surface area were validated against “ground truth” measurements, producing R 2 > 0.99 and a mean absolute percentage error < 10%. We demonstrate the ability to assess several important architectural traits, including canopy volume and projected area, and estimate relative growth rate in commercial chickpea cultivars and lines from local and international breeding collections. Detailed analysis of individual reconstructions also allowed us to investigate partitioning of plant surface area, and by proxy plant biomass. Conclusions Our results show that it is possible to use low-cost photogrammetry techniques to accurately reconstruct individual chickpea plants, a crop with a complex architecture consisting of many small leaves and a highly branching structure. We hope that our use of open-source software and low-cost hardware will encourage others to use this promising technique for more architecturally complex species. | Open source 3D phenotyping of chickpea plant architecture across plant development | 10.1186/s13007-021-00795-6 |
2021-09-15 | Background Neonatal admission hypothermia (HT) is a frequently encountered problem in neonatal intensive care units (NICUs) and it has been linked to a higher risk of mortality and morbidity. However, there is a disparity in data in the existing literature regarding the prevalence and outcomes associated with HT in very low birth weight (VLBW) infants. This review aimed to provide further summary and analyses of the association between HT and adverse clinical outcomes in VLBW infants. Methods In July 2020, we conducted this review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A systematic database search was conducted in MEDLINE (PubMed), Google Scholar, ScienceDirect, World Health Organization Virtual Health Library, Cochrane Library databases, and System for Information on Grey Literature in Europe (SIGLE). We included studies that assessed the prevalence of HT and/or the association between HT and any adverse outcomes in VLBW infants. We calculated the pooled prevalence and Odds Ratio (OR) estimates with the corresponding 95% Confidence Interval (CI) using the Comprehensive meta-analysis software version 3.3 (Biostat, Engle-wood, NJ, USA; http://www.Meta-Analysis.com ). Results Eighteen studies that fulfilled the eligibility criteria were meta-analyzed. The pooled prevalence of HT among VLBW infants was 48.3% (95% CI, 42.0–54.7%). HT in VLBW infants was significantly associated with mortality (OR = 1.89; 1.72–2.09), intra-ventricular hemorrhage (OR = 1.86; 1.09–3.14), bronchopulmonary dysplasia (OR = 1.28; 1.16–1.40), neonatal sepsis (OR = 1.47; 1.09–2.49), and retinopathy of prematurity (OR = 1.45; 1.28–1.72). Conclusion Neonatal HT rate is high in VLBW infants and it is a risk factor for mortality and morbidity in VLBW infants. This review provides a comprehensive view of the prevalence and outcomes of HT in VLBW infants. | Outcomes of neonatal hypothermia among very low birth weight infants: a Meta-analysis | 10.1186/s40748-021-00134-6 |
2021-09-15 | This paper deals with investigations of regional-scale assessment of low-enthalpy resources for cooling and heating in the Subsaharan area in Central Africa. The investigation of the ground is necessary to identify promising areas for the design, planning and development of Ground Source Heat Exchanger location. Two hundred boreholes with average deep of 47 m have been performed. The results of estimation based on subsurface thermal properties and hydrogeological parameters, using Geographic Information System, gives more details in the implantation of borehole heat exchanger (BHE) and groundwater heat exchanger (GWHE). The BHEs can be implanted in the Eastern and Northern part of the isostatic level map. GWHE can be installed in the zones of Makary, Goulfey and Kouseri at a depth less than 32 m. The exploitation of these geothermal systems in the area can help reduce greenhouse gases. Approximately 2900 ton/Ton of oil equivalent of CO 2 emissions per year can be reduced and 1,924 kilo ton of oil equivalent current consumption of electricity for cooling and heating can be saved by using geothermal energy. | GIS based exploring of low-enthalpy geo-energy potentials in the Subsaharan area in Central Africa | 10.1007/s40948-021-00290-1 |
2021-09-14 | Background Autoinflammatory diseases (AID) are rare chronic conditions with high disease burden, affecting children and adults. Clinically and genetically confirmed, AID can be effectively treated with targeted cytokine inhibition. In contrast, for patients with clinical AID symptoms without pathogenic gene variants, no treatment recommendations are available. Colchicine is approved and established as effective, safe and low-cost first-line therapy in Familial Mediterranean Fever. Up to now, efficacy data for colchicine in children with a clinical AID diagnosis without pathogenic gene variants are rare. This pilot study was performed to evaluate the effectiveness of colchicine in children with a clinical diagnosis of AID without pathogenic gene variants. Methods A pilot cohort study of consecutive children with active clinical AID without pathogenic gene variants treated with colchicine monotherapy was performed between 01/2009 and 12/2018. Demographics, clinical and laboratory characteristics were determined serially. Colchicine dosing and safety were documented. Physician estimate of disease activity was captured on visual analogue scales (VAS). Primary outcome: Complete response (PGA ≤2 plus CRP ≤0.5 mg/dL and/or SAA ≤10 mg/L) at last follow-up. Secondary outcomes: partial/no response, flare characteristics and requirement for rescue therapies. Analysis: Nonparametric comparison of disease activity measures. Results A total of 33 children were included; 39% were female. Median age at colchicine start was 3.8 years, median follow-up was 14.1 months. Clinical AID diagnoses included CAPS (24%), FMF (27%), PFAPA (43%) and unclassified AID (6%). At baseline, overall disease activity was moderate (PGA 4), inflammatory markers were elevated (CRP 12.1 mg/dL; SAA 289.2 mg/L), and 97% reported febrile flares. Outcome: 55% achieved complete response, 35% showed partial response and 58% had no febrile flares at last follow-up. Inflammatory markers (SAA: p < 0.0001, CRP: p < 0.005) and disease activity ( p < 0.0001) decreased significantly. Overall, 93% of children experienced improvement of flare characteristics. Conclusion Colchicine was found to be effective and safe in children with a clinical AID diagnosis in the absence of pathogenic gene variants. Colchicine is a low-cost treatment option for non-organ threatening AID. | Colchicine – an effective treatment for children with a clinical diagnosis of autoinflammatory diseases without pathogenic gene variants | 10.1186/s12969-021-00588-0 |
2021-09-13 | Background Plasma medicine is an innovative research field focused on the application of atmospheric-pressure low-temperature plasmas (ALTP) for therapeutic purposes. Considering the potentials of plasma in ophthalmology, in this study, we evaluated the safety of plasma on the conjunctival tissue in animal models for 6 months. Methods Twelve adult male New Zealand albino rabbits were divided into four groups. The right eye of each rabbit was chosen for the test and the left eye was considered as the control. Experiments were performed using the Plexr device (GMV, Rocca Priora, RM, Italy). Four plasma spots were applied on the superior part of the conjunctiva (from 10 to 2 o’clock positions) using the continuous mode and a low power level (white handpiece) of the Plexr. For evaluation of the plasma safety, the histopathological changes were assessed 1 week (A), 1 month (B), 3 months (C), and 6 months (D) after the intervention. Results According to the histopathological findings, a mild decrease in blood vessels and severe stromal edema, as well as a superficial epithelium loss, were observed in group A. No chronic inflammation, scar tissue, deposition, and hemorrhage were found in group B. Epithelialization was confirmed by the histological examinations after 1 month. There was no evidence of atypia or dysplasia after 3 and 6 months. Conclusion In conclusion, there were no persistent histopathological changes on conjunctival tissue after plasma exposure. Then, plasma can be considered as a minimally invasive alternative method for treating some ocular surface disorders. | Safety evaluation of the atmospheric low-temperature plasma (ALTP) on the conjunctiva: an animal study and histopathological findings; 6-month follow-up | 10.1186/s12886-021-02053-8 |
2021-09-12 | The membrane support is the basis for the preparation and application of the zeolite membrane and its cost and properties directly determine the performance of the zeolite membrane as well as its industrial applications. In this paper, the direct synthesis of NaA zeolite membrane on a novel low-cost support via an in situ reaction by utilizing natural clay can enable a significant reduction in manufacturing costs. During the preparation of the support for the NaA zeolite membrane, additives, such as Al 2 O 3 , Al(OH) 3 and AlF 3 , were combined with kaolin clay and used as alumina precursors. Using the resulting porous mullite support, the effects of the firing temperature on the permeability and pore structure of the support were investigated extensively. The results of the experiment showed that silica in the natural clay was reacted by the Al 2 O 3 precursor additives, producing a needle-like mullite in situ that served as a rigid skeleton porous structure for the support. Thus, a network porous structure of the mullite support could be formed during sintering process. The prepared network porous structure mullite supports exhibited a high pure water permeance of 3324 L m 2 h 1 bar 1 , open porosity of 41.8% and a mean pore size of 1.36 µm which was ideal for the preparation of the NaA zeolite membrane. | Novel preparation of low-cost support for NaA zeolite membrane by utilizing natural clay | 10.1007/s13201-021-01492-4 |
2021-09-09 | The aerodynamic performance of a roof depends significantly on its shape and size, among other factors. For instance, large roofs of industrial low-rise buildings may behave differently compared to those of residential homes. The main objective of this study is to experimentally investigate how perimeter solid parapets can alter the flow pattern around a low-rise building with a large aspect ratio of width/height of about 7.6, the case of industrial buildings/shopping centers. Solid parapets of varied sizes are added to the roof and tested in an open-jet simulator in a comparative study to understand their impact on roof pressure coefficients. Roof pressures were measured in the laboratory for cases with and without parapets under different wind direction angles (representative of straight-line winds under open terrain conditions). The results show that using a parapet can alter wind pressures on large roofs. Parapets can modify the flow pattern around buildings and change the mean and peak pressures. The mean pressure pattern shows a reduction in the length of the separation bubble due to the parapet. The parapet of 14% of the building’s roof height is the most efficient at reducing mean and peak pressures compared to other parapet heights. | Experimental investigation of the aerodynamics of a large industrial building with parapet | 10.1186/s42774-021-00080-z |
2021-09-09 | High dissolved organic carbon and low pH are often associated with elevated mercury content of fish in boreal lakes, but less is known about the fish mercury dynamics in lakes recovering from acidification stress. We measured total mercury concentration (THg) in muscle of European perch ( Perca fluviatilis ) and evaluated the overall correlation with environmental and growth variables in 24 boreal headwater lakes in the 2010s. We found negative correlations of length-corrected perch THg with lake pH and perch growth, but no correlation with dissolved organic carbon. The main emphasis in the present study was focused to a subset of ten lakes in southern Finland with known perch THg during severe acidification in the 1980–1990s. The comparison of perch THg concentrations in the 2010s with values determined in the 1980–1990s showed a sharp increase in most acidic lakes where the perch populations suffered from severe acid stress in the 1980s. This increase was attributed to growth condensation caused by sharp decrease in perch growth during recovery of reproduction capacity and the consequent increases in population densities of perch. Our results highlight the importance of perch growth rate and population density for understanding the variability of fish Hg in boreal headwater lakes, where recovery from acidification can lead to higher mercury concentration of fish in certain cases. | High Mercury Concentrations of European Perch (Perca fluviatilis) in Boreal Headwater Lakes with Variable History of Acidification and Recovery | 10.1007/s11270-021-05303-z |
2021-09-03 | Introduction Little is known about the underlying biomechanical cause of low back pain (LBP). Recently, technological advances have made it possible to quantify biomechanical and neurophysiological measurements, potentially relevant factors in understanding LBP etiology. However, few studies have explored the relation between these factors. This study aims to quantify the correlation between biomechanical and neurophysiological outcomes in non-specific LBP and examine whether these correlations differ when considered regionally vs. segmentally. Methods This is a secondary cross-sectional analysis of 132 participants with persistent non-specific LBP. Biomechanical data included spinal stiffness (global stiffness) measured by a rolling indenter. Neurophysiological data included pain sensitivity (pressure pain threshold and heat pain threshold) measured by a pressure algometer and a thermode. Correlations were tested using Pearson’s product-moment correlation or Spearman’s rank correlation as appropriate. The association between these outcomes and the segmental level was tested using ANOVA with post-hoc Tukey corrected comparisons. Results A moderate positive correlation was found between spinal stiffness and pressure pain threshold, i.e., high degrees of stiffness were associated with high pressure pain thresholds. The correlation between spinal stiffness and heat pain threshold was poor and not statistically significant. Aside from a statistically significant minor association between the lower and the upper lumbar segments and stiffness, no other segmental relation was shown. Conclusions The moderate correlation between spinal stiffness and mechanical pain sensitivity was the opposite of expected, meaning higher degrees of stiffness was associated with higher pressure pain thresholds. No clinically relevant segmental association existed. | A cross-sectional analysis of persistent low back pain, using correlations between lumbar stiffness, pressure pain threshold, and heat pain threshold | 10.1186/s12998-021-00391-4 |
2021-09-02 | As the condensed matter analog of Majorana fermion, the Majorana zero-mode is well known as a building block of fault-tolerant topological quantum computing. This review focuses on the recent progress of Majorana experiments, especially experiments about semiconductor-superconductor hybrid devices. We first sketch Majorana zero-mode formation from a bottom-up view, which is more suitable for beginners and experimentalists. Then, we survey the status of zero-energy state signatures reported recently, from zero-energy conductance peaks, the oscillations, the quantization, and the interactions with extra degrees of freedom. We also give prospects of future experiments for advancing one-dimensional semiconductor nanowire-superconductor hybrid materials and devices. | Experimental review on Majorana zero-modes in hybrid nanowires | 10.1007/s11433-021-1737-4 |
2021-09-01 | A study on the low-cycle fatigue (LCF) behavior of K416B alloy was conducted at 650 °C. According to the results, the LCF behavior of K416B alloy at 650 °C is mainly manifested as elastic deformation and the fatigue life of the alloy is determined by the level of material strength. When tension-compression fatigue occurs, the deformation mechanism of the alloy is reflected in the form of dislocation slip, and the deformation dislocations are bowed out in the matrix by Orowan mechanism, which leads to a dislocation configuration similar to the Frawk-Reed source. At the late stage of low-cycle fatigue, the fatigue-induced cracks develop from the alloy surface. As fatigue test proceeds, it is possible for the cracks to continue development along the regions of eutectic and the bulk M 6 C carbide due to stress concentration, thus causing the alloy to show cleavage fracture. 通过在 650 °C 低周疲劳性能测试和组织观察, 研究了 K416B 合金的低周疲劳行为. 研究结果表 明, K416B 合金在650 ℃低周疲劳行为主要以弹性变形为主, 合金的疲劳寿命取决于材料强度;在拉 压疲劳期间, 合金的变形机制是位错滑移, 且形变位错以 Orowan 机制在基体弓出, 形成类似于 F-R 源 的位错组态;在低周疲劳后期, 初始裂纹易萌生于合金表面;随着疲劳试验进行, 在共晶和块状 M6C 碳化物区域产生应力集中, 促使疲劳裂纹沿此处扩展并发生解离断裂. | Low-cycle fatigue behavior of K416B Ni-based superalloy at 650 °C | 10.1007/s11771-021-4797-4 |
2021-09-01 | Abstract— Using powders synthesized under optimal conditions, we have prepared Li 2 Zn 3 Ti 4 O 12 + ZnTiO 3 ceramics suitable for designing microelectronic components by low-temperature cofired ceramic (LTCC) technology. The sintering temperature of the ceramics has been lowered from 1075 to 950°C by adding a sintering aid with a eutectic composition in the Li 2 O–B 2 O 3 –SiO 2 system in an amount of 3.0 wt %. The material thus prepared has a high level of dielectric properties: ε r = 23.1 and Qf = 832 at a field frequency of 1 MHz. | Preparation and Properties of Li2Zn3Ti4O12-Based Ceramics with a Sintering Aid in the Li2O–B2O3–SiO2 System for LTCC Technology | 10.1134/S0020168521090156 |
2021-09-01 | Seasonality influences the abundance and activity of forest insects. Harvesting during periods of reduced activity could minimise colonisation risk on logs and reduce the need for phytosanitary treatments. We describe the winter colonisation dynamics of Pinus radiata logs in operational harvest sites in New Zealand and assess the probability of log colonisation as a function of captures in flight interception traps. After 15 days, 3% and 1% of logs were colonised by Hylastes ater and Hylurgus ligniperda (Coleoptera: Scolytinae), respectively, and 1% by Xenocnema spinipes (Coleoptera: Curculionidae). The same three species were captured in traps. Our observations showed that logs exposed for ≥ 2 weeks are predicted to have a more than 1% probability of bark beetle colonisation, whereas logs removed from forests within 24 or 48 h had predicted colonisation rates of 0.13% and 0.26%, respectively. A positive relationship between trap capture and log colonisation was also observed. Average catches of < 1 bark beetle per trap, three bark beetles per trap or ten bark beetles per trap equated to estimated log colonisation rates of < 10%, 14–98% or > 98% log colonisation. A positive relationship was also shown between log colonisation rates and temperature. A 12.3 °C temperature threshold predicted colonisation rates of 5, 50 and 95% with thermal sums of 10, 20 and 30 degree-hours, respectively. Models based on exposure time, trap catches, or environmental factors can estimate seasonal probability of insect colonisation, which aids identification of periods of low pest pressure when treatments could be avoided or reduced. | Bark beetles on pine logs: forecasting winter colonisation dynamics based on trap catches and temperature records | 10.1007/s10340-021-01361-8 |
2021-09-01 | Winter low temperature disturbance in the southern subtropics has important effects on the weed community structure, but the role of uniquely low temperatures in biological invasions is unclear. Here, we examined the competitive effects of an invasive plant, Bidens pilosa L., and its native congener, Bidens biternata (Lour.) Merr. et Sherff, during high and low temperature seasons to determine whether low temperatures promote the competitiveness of B. pilosa in the southern subtropics of China. The growth and physiological responses of the two Bidens species to low (10/5 °C) and optimum (30/25 °C) temperatures were examined to determine how the invasive B. pilosa responds to low temperature stress . Our results showed that the competitive balance index values of B. pilosa in low temperature seasons were significantly higher than those in high temperature seasons, which implied that low temperatures may be more beneficial to the competitiveness of B. pilosa than high temperatures in the southern subtropics. The smaller decline in the relative growth rate and the photosynthetic ability of B. pilosa compared with B. biternata under low temperature stress indicated that the former was less negatively affected by low temperature than the latter. A higher DPPH · (1.1-diphenyl-2-picrylhy-drazyl) scavenging rate and greater heat-stable protein content in B. pilosa under low temperatures might help the invasive plant to maintain more effective physiological functions and thus a higher growth rate. Overall, the uniquely low temperature in the southern subtropics of China is expected to promote the invasiveness of the exotic B. pilosa . | Winter low temperature disturbance in the southern subtropics of China promotes the competitiveness of an invasive plant | 10.1007/s10530-021-02547-y |
2021-09-01 | Creation of oxygen-containing functional groups on the biochar surface can highly improve its hydrophilicity and amend its behaviour in aquatic systems. Hydrogen peroxide, ozone, potassium permanganate and nitrogen acid were most usually used reagents for the surface oxidation. On the contrary, biochar activation by strong acids can be a costly process at the industrial scale and can raise environmental problems due to the disposal of activated carbon. Hence, there is a need to search for cheaper and cleaner products for the modification of biochar. For this reason, weak acids, such as solution of rhamnolipids or rainfall water solution, can be used. In this study, it was found that lower size biochar particles had higher wettability compared to larger size particles, since it was categorized as slightly hydrophobic (2.67 s). Steam of average concentration of rhamnolipid solution (20 mg/l) had the highest effect on the enhancement of biochar surface area (15.2 m 2 /g) and satisfactory impact on the reduction of initial hydrophobicity (4210 s). Biochar modified with increased concentration of nitric acid solution (from 65 to 20%) wettability was in accordance with the increase of surface area (from 4210 to 3907 s and from 1.27 to 4.36 m 2 /g). | Hydrophilicity enhancement of low-temperature lignocellulosic biochar modified by physical–chemical techniques | 10.1007/s10163-021-01255-y |
2021-09-01 | Single hat sectioned hybrid beams composed of aluminum and Carbon Fiber Reinforced Polymeric materials (CFRP), intended for structural applications in the automotive and aviation sectors, have been studied from the point of their energy absorption capabilities when submitted to transverse low-velocity impact loading. Carbon fiber-epoxy composite prepregs were placed on the inside of the single hat sectioned aluminum sheet and completely cured in the autoclave under the recommended curing cycle. The bonding process between the aluminum sheet and composite layers was achieved by using 3M VHB™ 4930 double-sided acrylic foam tape. Bonding the aluminum and composite layers through adhesive tape eliminates the requirement of surface preparation of the aluminum layer through chemical etching or mechanical abrasion and thereby the strength of the metallic layer is not reduced due to the formation micropores during the chemical etching process. Results are shown in terms of load-displacement and damage morphologies diagrams; characteristic trends are compared and discussed. It was observed that the presence of viscoelastic adhesive tape material restricts the rupture (visual cracks) failure of the outer aluminum layer, resulting in the only impact-induced indentation for all impact energies. Numerical simulations were also performed to characterize and predict the failure mechanism of such hybrid beams when subjected to impact loading. Numerical predictions showed good correlation with experimental results for all impact histories at low and medium impact energies but a showed slight discrepancy for highest impact energy and were not able to successfully capture the system response in the unloading region. Current modeling does not consider damage healing or recovery with unloading and it is difficult to account for such change in material state. This study provides the low-velocity impact characteristics and collapse behavior of the hybrid hat sectioned beams under tensile and shear forces developed by impact loading by providing insight to their primary damage mechanisms relative to the impact energies. It was found that the primary damage of the specimen’s changes from impact-induced indentation, minimal fiber breakage to partial perforation accompanied by larger indentation depth as the impact energy is increased from 6 to 12 J. | Low-Velocity Impact Characteristics of Hybrid Aluminum/CFRP Single Hat Sectioned Beam Adhesively Bonded Using Adhesive Tape | 10.1007/s40870-020-00277-1 |
2021-09-01 | Reliable high-altitude relight is a key combustor requirement for the aero-engine. In general, low pressure and low temperature at high altitude will result in difficult ignition after extinction. In the present work, a simulated high-altitude test facility was designed to establish the capability of high-altitude relight testing. A multi-channel plasma igniter (MCPI) was proposed and designed to obtain reliable altitude ignition. Furthermore, the ignition performance of the MCPI and the traditional spark igniter was compared under varying high-altitude conditions. The separation of the breakdown stage from the discharge was confirmed by observing a time-phased breakdown process between multi-couple electrodes during MCPI discharge. Moreover, the discharge efficiency of the power source is increased from 17 to 36% by MCPI. A plasma kernel with high energy and strong penetration was generated within microsecond scale, while a flame kernel with high energy and large initial volume was formed on millisecond scale. In addition, the stable flame was obtained rapidly owing to the preheating evaporation area expansion, the improving mixture and the increasing heat release. MCPI extends the ignition limit FAR by 39%, 30% and 10% at ground level, 4 km and 8 km, respectively. The advantage of initial flame kernel from MCPI is that it resists heat loss at low temperature, while it does not perform well at extremely low pressure due to the spark-to-glow transition. | Experimental Investigation on High-Altitude Ignition and Ignition Enhancement by Multi-Channel Plasma Igniter | 10.1007/s11090-021-10189-0 |
2021-09-01 | Thermosetting resin matrix is the key component of advanced wave-transparent composites, where low dielectric constant, excellent processability, high thermal stability, as well as good bonding ability are required for resins. Herein, we prepared a series of phenylethynyl terminated polyimide (PI) resins by grafting amine-functionalized hyperbranched polysiloxane (HBPSi) to PI chains during the in situ polymerization. The effects of HBPSi on the processability of oligomers, molecular packing, thermal stability, dielectric property and bonding ability to reinforce Kevlar fibers of the cured PI/HBPSi composite resins have been examined in detail. The dielectric constants of the cured composite resins were greatly reduced from 3.29 to 2.19 without compromising its processability and thermal stability. Meanwhile, the 10 wt% HBPSi-containing PI resin demonstrated better bonding ability to reinforce fibers with the interfacial shear strength (IFSS) of 37.64 MPa, compared with that of neat PI-6 matrix (27.34 MPa), and better adhesion to metal with the lap shear strength of 10.48 MPa, 50% higher than that of neat resin PI-6 (6.98 MPa). These resultant PI/HBPSi composite resins exhibit excellent comprehensive properties, indicating their great potential as low-dielectric constant resin matrix in radar radome. | Preparation of Low-dielectric Permittivity Polyimide Resins with High Surface Activity from Chemically Bonded Hyperbranched Polysiloxane | 10.1007/s10118-021-2585-0 |
2021-09-01 | Abstract — This article discusses a promising method for improving the tribological properties of the surface of structural high alloy steel with ultrafine grain structure by low temperature ion nitriding in multicomponent low-pressure glow discharge plasma. The effect of treatment by intense plastic torsion deformation on the structure and mechanical properties of the surface of structural materials is demonstrated. The features of ion nitriding of such materials after their grinding are analyzed. The surface properties of samples with coarse and ultrafine grain structures are compared after chemical-thermal treatment at various temperatures of holding. The structural phase composition of the surfaces after saturation with nitrogen at low temperature is analyzed. The mechanism of surface wear after deformation and subsequent nitriding in low-pressure glow discharge is revealed and determined. | Ion Nitriding of High Alloy Structural Steels with an Ultrafine Grain Structure at Various Temperatures | 10.1134/S1027451021050268 |
2021-09-01 | Low-temperature is one of the most severe abiotic stresses affecting the potato production as the cultivated potato ( Solanum tuberosum ) is frost sensitive. MicroRNAs have been identified in response to low-temperature stress in plants. Here, via high throughput sequencing, we described the profiling of low-temperature stress response to miRNA and mRNA in potato. Two small RNA and six mRNA libraries were constructed and sequenced. Exactly 294 known and 211 novel microRNAs were identified, 24 microRNAs had the higher expression quantity in Treatment group (EG) than in Control group (CG), and 80 microRNAs had the lower expression in EG than CG. A total of 3298 differentially expressed genes (DEGs) were detected, with 1629 up-regulated and 1669 down-regulated. The metabolism pathway of phenylpropanoid biosynthesis (ko00940) is the common KEGG pathway in differentially expressed miRNA and mRNA. In this pathway, StuPOD13654 and StuPOD32147 are peroxidase which mainly catalyzes the coniferyl and sinapyl alcohol to form guaiac wood lignin monomer and syringyl lignin monomer, which are controlled by stu-novel-miR28211 and stu-novel-miR43095. These indicated that microRNAs may play essential roles in the low-temperature tolerance of potato. | High-Throughput MicroRNA and mRNA Sequencing Reveals that MicroRNAs may be Involved in Peroxidase-Mediated Cold Tolerance in Potato | 10.1007/s11105-020-01272-5 |
2021-09-01 | The Ministry of Defense of the Russian Federation have developed a unique standard for Arctic diesel fuel, which implies attainment of low-temperature indices of diesel fuel below -65°C without additives. Because of its high commercial production, over the time from 2017 through 2020 PAO Slavneft-YaNOS (Slavneft-YaNOS PJSC) prepared experimental and semi-industrial batches of Arctic diesel fuel during several pilot-scale runs for the Ministry of Defense of the Russian Federation. This fuel has now been put into production. | Production of Arctic Diesel Fuel with Use Temperature Up to Minus 65°C | 10.1007/s10553-021-01287-y |
2021-09-01 | The thermodynamics data of crystalline states of two representative components in blood sugar, d -glucose and d -fructose, are significant in researching artificial synthesis and composition transformation in vivo. The heat capacities of d -glucose and d -fructose over a temperature range of 1.9–300 K were measured and calculated by the heat capacity measurement module of physical property measurement system (PPMS). The heat capacities of two compounds increased steadily with temperature, showing a smooth curve without any thermal anomalies. The heat capacity of d -glucose is greater than that of d -fructose in the range of 0 K < T < 80 K, which is smaller than that of d -fructose between 80 and 300 K. Based on the lattice vibration mode, factors of generating the difference heat capacity data between the two isomers were investigated. Additionally, the heat capacity data were fitted by low-temperature heat capacity theoretical model. The thermodynamic data that molar entropy change and molar enthalpy change over the temperature range of 0–300 K were calculated. The standard molar entropy of d -glucose and d -fructose at 298.15 K was calculated by heat capacity fitting to be 214.64 and 217.56 J K −1 mol −1 , all with an error of 0.21. | Low-temperature heat capacity of d-glucose and d-fructose | 10.1007/s10973-020-09849-8 |
2021-09-01 | The mold filling stage of the low-pressure powder injection molding process was simulated numerically and validated by experimental injections. For this, a feedstock formulated from a 17-4PH stainless steel powder (60 vol.%) and a wax-based binder system (40 vol.%) was used. The feedstock was characterized to obtain its thermal properties and rheological profiles at different temperatures. These were then implemented into the Autodesk Moldflow Synergy 2019 package, the numerical tool used for the simulation. The numerical results, including those pertaining to the injected length, the melt front velocity, and the pressure, were validated using a laboratory experiment set-up made of an injection press and two instrumented molds. The injected lengths predicted by the simulation were similar to the experimental short-shot results, with a relative difference below 0.5%. Since the injections were performed at constant volumetric flow, the injected length was not influenced by the feedstock temperature, but only by the shape of the mold cavity. Numerical and experimental results for the pressure were also compared. The agreement between the was good except at the end of the injection process. It is conjectured that the disagreement observed might be due to a difference in boundary conditions. The physical mold not being “air-tight” as the numerical one, an excess pressure could have been present in the latter. As a final note, this interesting simulation capability to predict the injection pressure experienced by a low-pressure (metallic or ceramic) powder injection molding feedstock was, to the best of the authors’ knowledge, for the first time, validated experimentally in this study using a low-pressure sensor placed in the mold during real-scale LPIM injections. | Mold filling simulation and experimental investigation of metallic feedstock used in low-pressure powder injection molding | 10.1007/s12289-021-01612-0 |
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