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2021-11-01 | Sodium ion batteries (SIBs) are alternatives to lithium ion batteries (LIBs), and offer some significant benefits such as cost reduction and a lower environmental impact; however, to compete with LIBs, further research is required to improve the performance of SIBs. In this study, an orthorhombic Na super ionic conductor structural Fe 2 (MoO 4 ) 3 nanosheet with amorphous-crystalline core-shell alignment was synthesized using a facile low-temperature water-vapor-assisted solid-state reaction and applied as a cathode material for SIBs. The obtained material has a well-defined three-dimensional stacking structure, and exhibits a high specific capacity of 87.8 mAh·g − 1 at a current density of 1 C = 91 mA·g − 1 after 1,000 cycles, which is due to the considerable contribution of extra surface-related reaction such as the pseudo-capacitive process. This material shows significantly improved cycling and rated behavior as well as enhanced performance under high- and low-temperature conditions, as compared to the same materials prepared by the conventional high-temperature solid-state reaction. This enhancement is explained by the unique morphology in combination with the improved kinetics of the electrochemical reaction due to its lower charge transfer resistance and higher sodium ion conductivity. | Low-temperature synthesis of Fe2(MoO4)3nanosheets: A cathode for sodium ion batteries with kinetics enhancement | 10.1007/s12274-021-3323-1 |
2021-11-01 | This work is focused on optimizing the properties of encapsulant for low-concentration photovoltaic (LCPV) modules leading to improved electrical power and module life. Thermal conductivity (TC), long-term shear modulus ( G ∞ ) and coefficient of thermal expansion (CTE) of backside encapsulant are optimized using finite element (FE) simulations on LCPV module. It is found that as compared with ethylene-vinyl acetate (EVA), increased TC can improve electrical power, while decreased CTE and G ∞ can improve module life. Polymer composites with improved properties are computationally designed using in-house built design codes. Thermoplastic polyurethane (TPU) and ceramic fillers (particularly Al 2 O 3 and AlN) with designated particle’s geometry and volume fraction are predicted as the most suitable constituents. The selected compositions are processed, and their properties are measured accordingly. The measured properties are used in the parent FE simulations to predict the expected values of electrical power and module life to confirm the feasibility of replacing EVA with TPU-composites. The proposed composite has a combination of high TC and tailored CTE and G ∞ , which lowers the cell temperature and thermal strains enhancing the electrical power by 4.38% and the module life by 93%, respectively. | Simulation Led Performance Evaluation and Design of Polymer Composite for Encapsulation of Low-Concentration Photovoltaic Modules | 10.1007/s11665-021-05999-4 |
2021-11-01 | It is known that the freezing of the road brings high risks to the traffic in winter. However, Traditional deicing technology has low deicing efficiency and severe damage to the road surface. Therefore, the new develop pavement conductive wearing surface with graphite heating film (PCWSG) could be one option to solve this problem. So the main objective of this paper is to investigate the road performance (high-temperature, low-temperature, moisture susceptibility, friction-resistance) of pavement conductive wearing surface with graphite heating film (PCWSG) and then evaluate its deicing potential. In this paper, several tests are conducted to evaluate the performance of PCWSG. The high-temperature performance is conducted by the laboratory wheel-tracking rut test. Low-temperature performance is characterized by the low-temperature bending test. Moisture susceptibility is studied by the freeze-thaw split test. Friction-resistance performance is estimated by the pendulum type friction coefficient measuring instrument and the small acceleration loading device. Furthermore, removing ice potential is studied by asphalt rutting slabs (various gradations) with graphite conductive wearing surface. The results show that pavement conductive wearing surface with graphite heating film (PCWSG) could improve the high-temperature, low-temperature, and friction-resistance compared with the original asphalt mixture. Although moisture susceptibility and wear performance decrease lightly but also satisfy the specification requirement. Moreover, removing ice potential of asphalt slabs with PCWSG results shows that AC-20 asphalt concrete with higher porosity has better deicing and snow removal effect. The PCWSG has lower heating and deicing cost and more effective deicing effects. | Pavement conductive wearing surface with graphite heating film de-icing potential and performance experimental study | 10.1007/s42947-020-0263-1 |
2021-11-01 | An analytical review of the problems and advantages of using low-basicity cements is given. In particular, the issues of reducing energy and raw material specific costs in the production of low-basicity cements, replacing mineral raw materials with man-made raw materials in the production cycle, as well as environmental protection in the production of low-basicity cements by reducing carbon and nitrogen oxide emission while saving energy costs are considered. Conclusions are drawn according to an analytical review of results. | Low-Basicity Cement, Problems and Advantages of its Utilization | 10.1007/s11148-021-00610-8 |
2021-11-01 | Abstract Thin dust from copper smelting production is a valuable raw material for the extraction of heavy nonferrous, noble, and rare metals. One feature of dusts is the high content of arsenic in them, which must be removed from the technological cycle in the form of a product suitable for safe storage. The combined technology for processing dust from the smelting industry, including the low-temperature firing (calcination) of dust in order to distill arsenic into a separate product and break up poorly soluble sulfide and ferrite zinc and copper compounds, is the most rational. The chemical and phase composition of Ausmelt technology dusts is presented. Thermodynamic calculations of the reactions occurring during the firing of these dusts were carried out in order to study the behavior of copper, zinc, arsenic and iron compounds during firing in the temperature range of 20–1000°C; the features of the formation and composition of solid phases; and optimization of the conditions of firing and distillation of arsenic. It is established that the calcination of dust allows the conversion of sparingly soluble sulfides and ferrites of zinc and copper into acid-soluble oxides and sulfates. The thermodynamic parameters of the reactions of sulfuric acid leaching of individual compounds of the cinder are determined. The results of laboratory studies showed that the calcination temperature of 550°C provides the most satisfactory results in the conversion of arsenic to sublimates (more than 95%) and the recovery of copper and zinc in solution during sulfuric acid leaching (more than 90%). The initial acidity of solutions of 50 g/dm 3 and a solution temperature of 60°C are sufficient to achieve high values of copper and zinc recovery into the solution. | Extraction of Nonferrous Metals and Arsenic from Thin Dusts of Copper Fuel Production by Combined Technology | 10.3103/S1067821221060146 |
2021-11-01 | Abstract This article provides an analysis of improving the maintainability, durability, and efficiency of using road-building machines due to the use of new technologies in the creation and repair work using new polymer composite materials that can withstand the effects of low temperatures. | Prospects of Application of Glue-Riveted Technology in the Creation and Repair of Road-Building Machines under Conditions of Sharp Thermal Fluctuations and Low Temperatures | 10.3103/S1052618821050046 |
2021-11-01 | Solar water heating is one of the most efficient solar technologies in the domestic sector. The most important component of the solar thermal systems is the solar collector, which converts solar radiation to useful thermal energy. There are many types of solar collectors, which are categorized based on the operating temperature (low, medium and high temperatures) or the working fluid (gas or liquid). One of the newest types of solar collectors is direct absorption solar collector in which solar radiation is absorbed through the working fluid, unlike other collectors that use the surface absorber or indirectly absorb the solar radiation. The common working fluid for DASC is the suspension of metal, metal oxide or carbon nanomaterials in solar common fluids (water, EG, PG and Therminol VP-1). In this review paper, the effect of design and operating parameters on the thermal performance of low-temperature direct absorption solar collector is summarized. Using the numerous studies done in this field, the efficiency enhancement of DASC by variation of the collector geometric properties, the flow properties (the flow rate and Reynolds number), the working fluid properties (the base fluid, the nanoparticle material and size, and the nanofluid concentration), and the collector design is identified. This paper also identifies the current challenges facing the direct absorption solar collectors and the future recommendations for developing and commercializing these collectors. | Effect of design and operating parameters on thermal performance of low-temperature direct absorption solar collectors: a review | 10.1007/s10973-020-10043-z |
2021-11-01 | Probable mechanisms for low-temperature insertion bonding were discussed. Graphical abstract | Low-Temperature Insertion Bonding using Electroless Cu-Co-P Micro-Cones Array with Controllable Morphology | 10.1007/s13391-021-00302-y |
2021-11-01 | Abstract Waste polyethylene terephthalate (PET) beverage containers have been carbonized in a nitrogen stream and chemically treated to obtain activated carbon. The potential sorbent has been physico-chemically characterized and tested for use in the solidification of liquid radioactive waste (LRW). For this purpose, we have determined main factors describing adsorption of the selected radioactive metals. It was found that adsorption process fulfils Freundlich and kinetic pseudo-second-order models. It has been also shown that activation of the raw PET carbon with using the ZnCl 2 solution leads to the best adsorption results of the radionuclides. Activated carbon obtained within this work appeared to be a potential candidate for a low-cost, chemically stable adsorbent for water decontamination. Procedures for the carbonization and activation need, however, to be improved. Graphic abstract Activated carbon obtained from waste polyethylene terephthalate (PET) beverage containers appeared to be a potential candidate for a low-cost, chemically stable adsorbent for water decontamination and the management of radioactive liquid wastes (LRW). | Carbon obtained from waste polyethylene terephthalate (PET) containers as potential sorbent of radionuclides from the contaminated aqueous solutions | 10.1007/s13762-020-03102-3 |
2021-11-01 | One of the main problems limiting further growth of the production of parts by the hot forging of porous preforms (HFPP) is that the materials are prone to brittle fracture due to the poor quality of interparticle jointing formed during hot deformation and the presence of impurities in the initial powders. We study an approach to enhance the mechanical properties and endurance performance of hot-deformed powder steels by adding sodium or calcium microadditives and using thermomechanical treatment. Sodium bicarbonate and calcium carbonate are used for microalloying. Carbon is added in the form of a pencil graphite powder. The temperature of heating porous preforms prior to hot forging and the carbon content in steels vary; the content of microalloying additives is, wt %, 0.2 for sodium and 0.3 for calcium. Mechanical properties and the contact and low-cycle fatigue life are tested on 5 × 10 × 55 mm and 10 × 10 × 55 mm prism-shaped specimens and (diameter) 26 × 6 mm cylindrical specimens. Thermomechanical treatment is shown to enhance (in comparison with carburizing and thermal treatment) the impact strength and endurance performance of hot-deformed powder steels with Na or Ca microadditives under contact and low-cycle fatigue loading and reduce the hot repressing temperature of porous preforms without compromising the mechanical properties of the powder steels. This may be associated with the formation of a more fine-grained structure and the emergence of high microstresses in the crystal lattice. Cooling down of preform surface layers in the process of hot forging creates conditions for ausforming in them. | Formation of Structure and Properties of Hot-Deformed Powder Steels Microalloyed with Sodium and Calcium in the Process of Thermal and Thermomechanical Treatment | 10.3103/S1067821221060080 |
2021-11-01 | Abstract Ni x Mn 3−x O 4 and Ni x Mn 3−x O 4 /T (T represents tourmaline) catalysts with a double-layer hollow structure were prepared by a rigid template method for low-temperature selective catalytic reduction of NO x with NH 3 (NH 3 -SCR). The catalytic activity and SO 2 tolerance performance of Ni x Mn 3−x O 4 catalyst were enhanced by the addition of 2 wt% tourmaline. The results showed the addition of tourmaline could affect the growth, shell thickness and redox property of the Ni x Mn 3−x O 4 catalysts. The relative contents of Mn 4+ and surface chemical oxygen were also increased by the addition of tourmaline, which were beneficial for improving the SCR activity, the catalyst showed 100% NO conversion in a low-temperature range of 125–240 °C. The mechanism of SCR reaction and SO 2 tolerance were analyzed by In-situ DRIFTS. The SCR reaction process mostly follows Langmuir–Hinshelwood (L–H) mechanisms. The primary NOx adsorption materials on Ni x Mn 3−x O 4 /T catalyst were nitrate bidentate and bridge nitrate, which was not affected by SO 2 , and it had excellent SO 2 tolerance at 150 ℃. Graphic Abstract | Effect of Tourmaline Addition on the Catalytic Performance and SO2 Resistance of NixMn3−xO4 Catalyst for NH3-SCR Reaction at Low Temperature | 10.1007/s10562-021-03585-w |
2021-11-01 | Properties are provided for submicron aluminum oxide developed in SAO PKF NK for low-cement refractory concretes, and also for the LCRC of aluminosilicate composition obtained. It is demonstrated that the properties of concretes prepared on the basis of the alumina developed are no worse than domestic and imported analogs. | Low-Cement Refractory Concretes of Aluminum Silicate Composition Based on Submicron Aluminum Oxide Grade NK-Alumina 14 | 10.1007/s11148-021-00617-1 |
2021-11-01 | To quicken the process for high global warming potential (GWP) working fluid replacement for organic Rankine cycle (ORC) systems, a thermo-economic evaluation of low GWP fluid R1233zd(E) as an R245fa alternative has been performed in comparison with other natural fluids n-Pentane, Isopentane, and Isobutane for geothermal applications. The heat source water mass flow rate remains constant and 5 K pinch point is set for both evaporator side and condenser side. All working fluids have a close net thermal efficiency within 2%. Increasing the heat source from 120 °C to 160 °C gives a more than 20% efficiency rise. The low critical temperature of Isobutane limits its application for 160 °C heat source. R1233zd(E) displays a close mass flow rate (within 2%) from R245fa and others exhibit more than 40% flow rate reduction. The component level performance has also been investigated in this study. All alternatives exhibit a lower evaporator side (evaporator and preheater) heat transfer area than baseline R245fa, and a slightly higher condenser side (condenser and desuperheater) heat transfer area. For turbine performance, R245fa displays the highest volume flow ratio, indicating a significant change of the rotor blade height should be made between the inlet and outlet point for the expansion process. R1233zd(E) displays ∼10% increase for turbine size parameter from baseline, n-Pentane shows ∼22% rise, Isopentane exhibits ∼11% rise, while Isobutane presents 32% decrease, respectively. In general, R1233zd(E) only exhibits ∼2.3% higher specific investment cost than R245fa, while n-Pentane and Isopentane exhibit more than 15% cost rise. Thus, from the thermo-economic scale with an extended application range, R1233zd(E) exhibits a better overall performance index when compared with other R245fa alternatives and can be serviced as promising candidate to replace R245fa. | Thermo-economic evaluation of R1233zd(E) as an R245fa alternative in organic Rankine cycle for geothermal applications | 10.1007/s11814-021-0936-8 |
2021-11-01 | The effect of quenching from the intercritical temperature range on formation of martensite-ferrite structure in steel 10Kh3G3MFS deformed preliminarily by the method of cold radial forging is considered. The microstructure of the steel is studied using optical and scanning electron microscopes. The post-quenching grain size and microhardness of the steel are determined. Tensile and impact bending tests are conducted. The dependence of the mechanical properties of the steel on the quenching mode is described. The diagrams of structural strength are used to show the possibility of formation of different combinations of strength and impact toughness by changing the heating temperature and the time of the isothermal hold in incomplete quenching. | Laws of Formation of Structure and Properties in Cold-Deformed Low-Carbon Structural Steel Under Incomplete Quenching | 10.1007/s11041-021-00694-6 |
2021-11-01 | Abstract The effect of Sn9Zn–xSiC composite solder on the wetting and soldering behavior of 6061 aluminum alloys is investigated using a kind of new water-soluble organic flux through optical and electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The oxide film of 6061 aluminum alloys during the soldering process is composed of three-layer structure of different components, which are followed MgAl 2 O 4 , Al 2 O 3 and Al from the outside to the inside. The flux removes the oxide film by the dissolution reaction. A solid solution layer can be developed by undergoing displacement reaction with the Al-rich phase. With the increasement of SiC micron particle content, the spreading area of the composite solders increases firstly and then decreases. When the weight percentage of SiC micro-particles in the composite solder was 0.75%, the spreading area reached the maximum value, which increased by 38.9% compared with Sn9Zn–0.25SiC composite solder. Graphic Abstract | Removal of Oxide Film and Wetting Behavior of Sn9Zn–xSiC Composite Solder on 6061 Aluminum Alloy with Activated Organic Water-Soluble Flux | 10.1007/s12540-020-00850-2 |
2021-11-01 | Abstract The temperature dependences of magnetic properties and magnetic field behavior of Co/Gd/Co thin-film three-layer systems obtained via ion-plasma magnetron sputtering are studied. The thickness of cobalt layers is 5.0 nm and of Gd layers ( t Gd ) varies from 3.0 to 10.0 nm. The bulk magnetic characteristics of the samples were measured on a vibration magnetometer with an external magnetic field oriented parallel to the plane of the samples. The influence of the temperature and the thickness of a Gd layer on the shape of the hysteresis loops, the values of the magnetic moment m and the coercive force H C are discovered. In particular, when the temperature changes from 100 to 300 K, the coercive force decreases, and the magnetic moment increases at a temperature above 150 K. The m value decreases with an increase in thickness of gadolinium. | Temperature Dependence of Magnetic Properties and Magnetic Field Behavior of Co/Gd/Co Thin-Film Three-Layer Systems | 10.1134/S1063783421100140 |
2021-11-01 | In order to solve problems associated with food loss and the production of fresh drinking water, a device for low temperature freezing of water from concentrated products (cryoconcentrator) is proposed. Features of the proposed design of a capacitive cryoconcentrator using frozen ice as a cold storage mass for pre-cooling the product are discussed. In addition, a methodology for calculating the dynamics of freezing of water ice on the inner cylindrical surface — i.e., the working surface — of the proposed cryoconcentrator, is presented. | Dynamics of Water Ice Formation during the Operation of Vessel Cryoconcentrators | 10.1007/s10556-021-00976-z |
2021-11-01 | A novel hybrid of graphene-carbon nanotubes (HRGC) was prepared by tannic acid (TA)-functionalized reduced graphene oxide (RGO) and the amino-functionalized multi-walled carbon nanotubes (AMCNT). TA was used as the coupling agent for the successful low temperature nanowelding between RGO and AMCNT based on the Schiff base reaction. Due to the synergistic dispersion effect of RGO and AMCNT, which prevents restacking and re-aggregating of both RGO and AMCNT, HRGC hybrids were distributed evenly in the PA66 matrix. The inclusion of the HRGC as the structural reinforcement filler has improved the mechanical properties of PA66. With a 0.3 wt% HRGC loading, the tensile strength and Young’s modulus can reach to 749.23 MPa and 3.06 GPa, respectively, which is increased by 109.5 % and 77.9 % compared with the neat PA66 fiber. In addition, the crystallinity, thermostability and thermal conductivity of HRGC/PA66 composites were all improved. It is believed that a new strategy of constructing the efficient graphene- carbon nanotubes hybrid fillers has been established. | Low-temperature Nanowelding between Graphene and Carbon Nanotubes for High Performance of Polyamide 66 Composites | 10.1007/s12221-021-0375-5 |
2021-11-01 | Abstract The paper presents the results of a study of the relationship between strength and performance (ductile–brittle transition temperatures T db and zero plasticity NDT, critical opening at the crack tip CTOD at a test temperature of –40°C) on the structural parameters of hot-rolled plate made of low-carbon low-alloy steels with different contents of the main alloying and microalloying elements. | Relationship of Structure Parameters with Performance Characteristics of Shipbuilding Steels of Different Alloying | 10.1134/S2075113321060253 |
2021-11-01 | Abstract Four Nb–V–Ti steel plates of API 5LX70 linepipe were produced with changing accelerated cooling rate and finish rolling temperature using thermomechanical controlled process. The changes in ductile fracture surface, brittle fracture surfaces, including initial cleavage fracture and inverse fracture, arrowhead marking surfaces, and delamination were investigated using drop-weight tear test at temperatures of 0 °C and − 10 °C. Based on the drop-weight tear test results, an increase in the accelerated cooling rate, resulting in an increase in the volume fraction of quasi polygonal ferrite, fine polygonal ferrite, and granular ferrite microstructures, increased the percentage of ductile fracture surface and decreased the percentage of brittle fracture surfaces. Moreover, a reduction in the finish rolling temperature led to similar changes in the ductile fracture surface and brittle fracture surfaces due to an increase in the volume fraction of aciculae ferrite. Arrowhead markings surfaces, caused by the presence of banded structures, their percentage was reduced by increasing the accelerated cooling rate and decreasing the finish rolling temperature at the temperature of 0 °C. Furthermore, as the accelerated cooling rate increased, the number, length, thickness, and depth of delaminations were reduced at temperatures of 0 °C and − 10 °C. Graphic Abstract | Effect of Accelerated Cooling Rate and Finish Rolling Temperature on the Occurrence of Arrowhead Markings in Drop-Weight Tear Test of API 5LX70 Linepipe Nb–V–Ti Steel Plate | 10.1007/s12540-020-00841-3 |
2021-11-01 | This article presents the effect of thermal aging on threshold field strength and relative permittivity of cross-linked polyethylene (XLPE) with different cross-linking agent contents. Here, low-density polyethylene (LDPE) and dicumyl peroxide (DCP) are used as basic experimental material and cross-linking agent, respectively. Eventually, experimental results indicate that thermal aging can gradually make threshold field strength and relative permittivity of XLPE with different DCP contents increase and decrease, respectively. Besides, threshold field strength of XLPE with different DCP contents increases first and then decreases as the increase of DCP content, while relative permittivity of XLPE with different DCP contents decreases first and then increases as DCP content increases at different thermal aging time, etc. These studies in this article are the basis of the research on space charge accumulation and dissipation inside XLPE materials, which are of great significance to the normal operation of XLPE cables. | Effect of Thermal Aging on Threshold Field Strength and Relative Permittivity of Cross-Linked Polyethylene with Different Cross-Linking Agent Contents | 10.1007/s42835-021-00823-4 |
2021-11-01 | Abstract Low drop failure tendency and reduced cost of low silver SAC alloys has provoked researchers to exploit their potential for portable electronics. Low Bi addition in near-eutectic SAC alloys has proven confinement of IMC layer. In order to exploit potential of Ag variation (0.5–1.5 wt%) on structural, thermal, wettability and IMCs layers growth during thermal aging in low Bi-low Ag, Sn–xAg–0.7Cu–1.0Bi alloys were investigated. The resulting microstructure were characterized by scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction. Furthermore, structure–property correlations were established. This study signifies that 1.5 wt% Ag is responsible for lower melting point (220.18 °C) and lower contact angle (33°) in low Bi-low Ag, Sn–xAg–0.7Cu–1.0Bi alloys. Moreover, increment in Ag content restricted the interfacial IMC layer growth during thermal aging making them reliable for use in portable electronics. The microstructural investigations inferred that 0.5 wt% Ag solder joint with Cu substrate had the highest growth rate (0.34 μm/h 1/2 ) of IMC layer thickness while 1.5 wt% Ag solder joint had lowest growth rate (0.17 μm/h 1/2 ). Graphic Abstract | Structural, Thermal and Wetting Characteristics of Novel Low Bi-Low Ag Containing Sn–x.Ag–0.7Cu–1.0Bi (x = 0.5 to 1.5) Alloys for Electronic Application | 10.1007/s12540-020-00880-w |
2021-11-01 | Abstract The (5–15)%CoO/ZrO 2 (T + M) catalysts were studied by XRD and TPR-H 2 . In the oxidized samples, 80–90% of cobalt oxide is present in the form of finely dispersed Co 3 O 4 , which interacts with the support ( $${\text{Co}}_{x}^{{3 + }}{\text{Co}}_{y}^{{2 + }}{\text{O}}_{z}^{{2 - }}$$ clusters), and the rest of it (10–20%) are the Co 3 O 4 phase and dispersed CoO. In the CO oxidation to CO 2 , the most active samples were CoO/ZrO 2 (T + M) containing 10 and 15% cobalt at T 50 = 120°C. Nearly 100% conversion of CO to CO 2 was observed on 10%CoO/ZrO 2 (T + M) at 160–200°C. The conversion decreases at 220–260°C as a result of competition for oxygen in the oxidations of CO and H 2 , and at 280–360°C, as a result of increased consumption of CO in the methanation reaction. The CO oxidation in the range 50–200°C occurs on the clusters localized on the ZrO 2 (T) particles. The Co 3 O 4 phase in pure oxide and in the 5%CoO/(SiO 2 , ZrO 2 (M)) catalysts has low activity under these conditions. The temperature dependence of CO conversion was discussed based on the data on the properties of adsorption complexes formed with participation of oxygen clusters and the gas phase. | The Nature of the Activity of СoО/ZrO2 Catalysts in CO Oxidation with Oxygen in Excess Hydrogen | 10.1134/S0023158421060070 |
2021-11-01 | The low temperature of sewage in north China results in low performance of biological treatment at municipal wastewater treatment plants (MWTPs), especially in biological nitrogen removal. A modified two-stage A/O process with an embedded biofilm was proposed to enhance nitrogen removal. The operation performance of a pilot test was compared with an A 2 /O and SBR process at existing MWTPs to investigate the resistance to low temperature. The microbial communities for the three processes were compared based on the metagenomics results of 16sDNA high-throughput sequencing from activated sludge. The modified A/O resulted in a higher average removal of COD (90.12%) than A 2 /O (85.23%) and SBR (83.03%), especially of small-molecule organic compounds (< 500 Da) and macromolecular refractory organics (> 5 k Da); the TN removal rate of A2/O, SBR and the modified A/O was also increased from 74.47%, 70.63% and 78.46%, respectively. High-throughput sequencing revealed increased microbial diversity and an abundance of denitrifying functional bacteria was observed in the modified A/O process at low temperatures. The abundance of nitrite oxidation bacteria (NOB) including Nitrosomonas and Nitrospira , the amount was 1.76% and 2.34% in modified A/O, respectively, whereas NOB only accounted for 1.82% in A 2 /O and 1.35% in SBR. | Comparison of nitrogen removal efficiency and microbial characteristics of modified two-stage A/O, A2/O and SBR processes | 10.1007/s10653-021-00855-9 |
2021-11-01 | Abstract Coal samples of three ranks are investigated: long-flame (D) coal, long-flame gas (DG) coal, and gas (G) coal. The composition and properties of the coal samples and their thermal-destruction products are studied by the following methods: proximate analysis, ultimate analysis, petrographic analysis, thermogravimetry, and chromatography and mass spectroscopy. In low-temperature thermal destruction, solid, liquid, and gaseous products are formed. The liquid products consist of a complex mixture of saturated and aromatic hydrocarbons. Normal and branched n -alkanes and n -alkenes are also identified. The molecules of the aromatic hydrocarbons contain 1–5 benzene rings. The molecules CO 2 , H 2 , H 2 S, NH 3 , HCN, C 4 H 5 N, C 6 H 12 , CH 4 , and CO are identified in the gaseous products by mass spectrometry. | Low-Temperature Thermal Destruction of Kuznetsk Basin Coal: Product Composition | 10.3103/S1068364X21110041 |
2021-11-01 | Melting in ceramic crucibles is one of the stages in jewelry recycling. The consistency of the concrete mass plays an important role in molding large-scale refractory crucibles through vibratory casting. This article discusses the impact of commercially available dispersants (Castament FS 10, Melflux 1641 F, Peramin Al 200, FF7 Spezial, and PC-1701) on the rheology of the low-cement concrete mass of the corundum–mullite–zirconium composition and the materials’ physical and mechanical properties. The best results were obtained using the PC-1701 dispersant. | Effect of Dispersants on the Properties of Low-Cement Concrete for Jewelry Waste Melting Furnaces | 10.1007/s11148-021-00627-z |
2021-11-01 | This study aimed to develop a cryopreservation protocol for the long-term preservation of yacon [ Smallanthus sonchifolius (Poepp. and Endl.)], an Andean crop with high fructooligosaccharide content in its tuberous roots. Initially, the cryopreservation protocol was developed using a yacon clone originated from Ecuador classified as ECU 41. Osmotic dehydration of apical buds (2–3 mm long) was carried out by assessing two plant vitrification solutions, PVS2 (15, 30, and 60 min) at 0 °C and PVS3 (30, 45, 60, and 75 min) at 22 °C. After cryopreservation, the apical buds were thawed and placed on MS medium ± 0.1 mg l −1 N 6 -benzyladenine (BA). The survival rates ranged from 37 to 90% within all treatments, with those subjected to PVS2 and PVS3 for 60 min showing the highest survival rates on MS medium without BA (87 and 90%, respectively). At 12 weeks post cryopreservation, these treatments also provided the highest regrowth rates, both reaching 73% of normally growing (shooting, rooting) plantlets. Survival rates on MS + 0.1 mg l −1 BA regrowth medium reached up to 90%; however, regrowth into normally rooted plantlets did not exceed 67% post cryopreservation. The optimized protocols were then applied to 4 additional yacon clones originated from Bolivia and Peru, classified as BOL 22, BOL 23, PER 12, and PER 14. This resulted in survival and regeneration rates ranging between 79.7–94.1% and 66.3–75.4% respectively. Our study shows that optimal cryopreservation protocols for the long-term conservation of yacon can be based on both PVS2 and PVS3 vitrification solutions. An efficient PVS2 and PVS3 based cryopreservation protocol for yacon was developed, ensuring shoot tip survival of up to 94.1% and subsequent regrowth up to 75.4% after cryopreservation. | Droplet-vitrification methods for apical bud cryopreservation of yacon [Smallanthus sonchifolius (Poepp. and Endl.) H. Rob.] | 10.1007/s11240-021-02116-0 |
2021-11-01 | Background Low light is a primary regulator of chrysanthemum growth. Our aim was to analyse the different transcriptomic responses of two Chrysanthemum morifolium cultivars to low light. Methods and results We conducted a transcriptomic analysis of leaf samples from the ‘Nannonggongfen’ and ‘Nannongxuefeng’ chrysanthemum cultivars following a 5-day exposure to optimal light (70%, control [CK]) or low-light (20%, LL) conditions. Gene Ontology (GO) classification of upregulated genes revealed these genes to be associated with 11 cellular components, 9 molecular functions, and 15 biological processes, with the majority being localized to the chloroplast, highlighting the role of chloroplast proteins as regulators of shading tolerance. Downregulated genes were associated with 11 cellular components, 8 molecular functions, and 16 biological processes. Heat map analyses suggested that basic helix–loop–helix domain genes and elongation factors were markedly downregulated in ‘Nannongxuefeng’ leaves, consistent with the maintenance of normal stem length, whereas no comparable changes were observed in ‘Nanonggongfen’ leaves. Subsequent qPCR analyses revealed that phytochrome-interacting factors and dormancy-associated genes were significantly upregulated under LL conditions relative to CK conditions, while succinate dehydrogenase 1, elongated hypocotyls 5, and auxin-responsive gene of were significantly downregulated under LL conditions. Conclusions These findings suggest that LL plants were significantly lower than those of the CK plants. Low-light tolerant chrysanthemum cultivars may maintain reduced indole-3-acetic acid (IAA) and elongation factor expression as a means of preventing the onset of shade-avoidance symptoms. | Comparison of the transcriptomic responses of two Chrysanthemum morifolium cultivars to low light | 10.1007/s11033-021-06729-8 |
2021-11-01 | Substrates provide the necessary support for scientific explorations of numerous promising features and exciting potential applications in two-dimensional (2D) transition metal dichalcogenides (TMDs). To utilize substrate engineering to alter the properties of 2D TMDs and avoid introducing unwanted adverse effects, various experimental techniques, such as high-frequency Raman spectroscopy, have been used to understand the interactions between 2D TMDs and substrates. However, sample-substrate interaction in 2D TMDs is not yet fully understood due to the lack of systematic studies by techniques that are sensitive to 2D TMD-substrate interaction. This work systematically investigates the interaction between tungsten disulfide (WS 2 ) monolayers and substrates by low-frequency Raman spectroscopy, which is very sensitive to WS 2 -substrate interaction. Strong coupling with substrates is clearly revealed in chemical vapor deposition (CVD)-grown monolayer WS 2 by its low-wavenumber interface mode. It is demonstrated that the enhanced sample-substrate interaction leads to tensile strain on monolayer WS 2 , which is induced during the cooling process of CVD growth and could be released for monolayer WS 2 sample after transfer or fabricated by an annealing-free method such as mechanical exfoliation. These results not only suggest the effectiveness of low-frequency Raman spectroscopy for probing sample-substrate interactions in 2D TMDs, but also provide guidance for the design of high-performance devices with the desired sample-substrate coupling strength based on 2D TMDs. | Unveiling the origin of anomalous low-frequency Raman mode in CVD-grown monolayer WS2 | 10.1007/s12274-021-3769-1 |
2021-11-01 | Surface latent heat flux (LHF) is an important component in the heat exchange between the ocean and atmosphere over the tropical western North Pacific (WNP). The present study investigates the factors of seasonal mean LHF variations in boreal summer over the tropical WNP. Seasonal mean LHF is separated into two parts that are associated with low-frequency (> 90-day) and high-frequency (≤ 90-day) atmospheric variability, respectively. It is shown that low-frequency LHF variations are attributed to low-frequency surface wind and sea-air humidity difference, whereas high-frequency LHF variations are associated with both low-frequency surface wind speed and high-frequency wind intensity. A series of conceptual cases are constructed using different combinations of low- and high-frequency winds to inspect the respective effects of low-frequency wind and high-frequency wind amplitude to seasonal mean LHF variations. It is illustrated that high-frequency wind fluctuations contribute to seasonal high-frequency LHF only when their intensity exceeds the low-frequency wind speed under which there is seasonal accumulation of high-frequency LHF. When high-frequency wind intensity is smaller than the low-frequency wind speed, seasonal mean high-frequency LHF is negligible. Total seasonal mean LHF anomalies depend on relative contributions of low- and high-frequency atmospheric variations and have weak interannual variance over the tropical WNP due to cancellation of low- and high-frequency LHF anomalies. | Factors of boreal summer latent heat flux variations over the tropical western North Pacific | 10.1007/s00382-021-05835-4 |
2021-11-01 | Abstract The phase composition, microstructure, mechanical properties and stability of foils of (Sn 4 In) 100– х Bi x ( х = 0–8 at %) alloys synthesized by the method of ultrafast quenching from the melt at cooling rates up to 10 5 K/s are studied. Rapidly hardened foils of (In 4 Sn) 100– х Bi x alloys at a bismuth concentration of less than 4 at % consist of solid solutions of bismuth in the γ phase (Sn 4 In) and tin, and foils of the (In 4 Sn) 92 Bi 8 alloy consist of a solid solution of bismuth in the γ phase and tin, as well as the ε phase (BiIn). During aging of the foils at room temperature, the size of inclusions of the ε phase increases due to the decomposition of supersaturated solid solutions of bismuth in the γ phase (Sn 4 In) and tin. The studied foils have a microcrystalline structure. The difference in the shape and size of the grains on the side of the foil adjacent to the crystallizer and the freely solidifying side is revealed. The texture of the γ phase in foils depends on the concentration of bismuth. Doping of the γ phase with bismuth leads to an increase in microhardness. Aging of the (InSn) 100– х Bi x ( x = 0, 2 and 4 at %) foils at room temperature for 30 h causes a steady increase in the microhardness. | Structure and Microhardness of (Sn4In)100 – хBix (x = 0–8 аt %) Alloys Produced by High-Speed Cooling | 10.1134/S1027451021060446 |
2021-11-01 | User-friendly fingerprint powders, namely efficient, low-cost and nontoxic ones, are always desirable for the development of latent fingerprints (LFPs). Here, we described the use of pristine graphic carbon nitride quantum dots (g-C 3 N 4 QDs) as a new kind of user-friendly fingerprint powder. The g- 3 N 4 QDs can be easily prepared from urea and sodium citrate precursors through low temperature solid-phase reaction. Due to their good optical properties and selective interactions with secretion residuals, the g- 3 N 4 QDs powders were exploited to develop LFPs on different substrates by the powder dusting technique. The LFP images on a plastic bag exhibited a high ridge and furrow contrast ratio, allowing for easy identification of level 1–3 details of LFPs. This work indicates that the g- 3 N 4 QD powders provide good performance for LFP visualization and is likely to be adopted for some applications in forensic investigations. | Pristine Graphic Carbon Nitride Quantum Dots for the Visualized Detection of Latent Fingerprints | 10.2116/analsci.20P336 |
2021-11-01 | Comparative studies of the microstructure, porosity and hardness of the surface layer of a low-carbon steel are performed after nitrocarburizing by traditional single-cycle and novel multi-cycle treatments. The sizes and the content of pores in the surface layer are determined, the profile of the variation of microhardness over its thickness is plotted, and an x-ray diffraction analysis is performed. It is recommended to use multi-cycle nitrocarburizing for surface treatment of parts from low-carbon steels in order to raise the operating characteristics of the parts. | Effect of Multi-Cycle Nitrocarburizing on the Microstructure and Surface Hardness of Low-Carbon Steel | 10.1007/s11041-021-00699-1 |
2021-11-01 | Investigation of the fatigue response of friction stir-welded (FSWed) joints is especially important in the design and manufacturing of components with exposure to cyclic loading. In this study, cyclic response of FSWed pure copper joints is investigated in the low-cycle fatigue regime. Microstructural characterizations revealed that FSW introduced a severely deformed microstructure in the nugget zone (NZ). Fatigue response was determined at a strain ratio of 0.1 by varying the total strain amplitude from 0.1 to 0.6%. Cyclic softening was observed for the low strain amplitude of 0.1%, whereas hardening was detected at higher strain amplitudes. The hysteresis loops demonstrated symmetricity along with noticeable linear behavior after the reversals. Typical fractures occurred in the heat affected zone (HAZ) rather than the NZ or the base metal due to grain coarsening of the HAZ. Improved cyclic properties of the NZ along with stable behavior up to 1000 cycles at a total strain amplitude of 0.3% were attributed to its fine and homogeneous microstructure. Moreover, fracture surface analysis demonstrated a ductile behavior represented by dimples in the sample strained at 0.1% in contrast with a brittle fracture surface of the sample fatigued at 0.5% strain amplitude. | Low-Cycle Fatigue Behavior of Friction Stir-Welded Copper Joints | 10.1007/s11665-021-06034-2 |
2021-11-01 | Abstract The biological degradation of mixed composites of low density polyethylene (PE) with natural rubber (NR) in soil is studied. The biodegradability of composites was monitored through changes in the mass, appearance, and chemical composition of the materials using infrared spectroscopy. Analysis of the changes in the IR spectra of the samples after exposure to soil showed a decrease in the cis -1,4-double bonds, as well as the formation of carbonyl groups and functional groups belonging to the biomaterial. The results obtained agree with the concept of the oxidative mechanism of the initial stage of the NR biodegradation process and provide information on the accumulation of biomass in blends of low-density PE and NR, depending on the composition. | Biodegradation of Blends of Low-Density Polyethylene with Natural Rubber in Soil | 10.1134/S1990793121060257 |
2021-11-01 | The impacts of the low level jets that form through the gaps in the topography in the Limpopo and Zambezi River Valleys (LRV and ZRV) on southern African climate are investigated. ERA-5 reanalysis data and numerical experiments using regional climate models reveal that the two valleys act as main gateways for southwest Indian Ocean-sourced moisture inflows into southern Africa. The effects of the LRV jet are stationary and mostly confined to south of Limpopo. By blocking the LRV, the moisture convergence in the interior of the subcontinent reduces and leads to a weakening in both the Angola Low and the ridging high over southeastern Africa. These are unfavorable conditions for the southward transport of moisture, causing a decrease of up to 50% of the subtropical southern African total summer rainfall. In contrast, the influence of the Zambezi jet varies with the season. During early austral summer, a blocked ZRV results in an overall deficit in rainfall in the subcontinent. It then leads to a weaker Mozambique Channel Trough, intensified Angola Low, hence increase in rainfall during January and February. Toward the end of the austral summer season, the absence of the Zambezi jet allows more moisture from the tropical Atlantic to penetrate into the mainland which then converges with moisture transported from the Indian Ocean and triggers excess rainfall over the tropical areas. These results have important implications for understanding the intraseasonal and interannual rainfall variability over the subcontinent during the summer half of the year. | The influence of southeastern African river valley jets on regional rainfall | 10.1007/s00382-021-05846-1 |
2021-11-01 | Abstract— The long-term data (2000–2017) on the abundance of burbot larvae (Lota lota L., 1758) during the downstream migration from the spawning areas in the spawning tributaries of the Ob River (the Voykar and Sob rivers) and in feeding areas in the floodplain system are analyzed. The average absolute abundance of feeding burbot larvae was 12.4 million specimens in the Voykar River and 7.3 million specimens in the Sob River. The average proportion of survived larvae which started exogenous feeding of the number of hatched larvae was 0.78 and 0.59%, respectively. The total abundance of feeding larvae is determined by the number of juveniles which migrated downstream from the spawning tributary: in the Voykar River, r Sp = 0.741, p = 0.006, in the Sob River, r Sp = 1.000, p < 0.001. The correlation between the survival of burbot larvae in the floodplain and environmental factors affecting the juveniles until their complete transition to exogenous feeding was found. For example, in the Voykar River the correlation between the survival rate and duration of flooding at the level of 7 m was r Sp = 0.732, p = 0.007; between the survival and average daily temperature for 14 days was r Sp = 0.921, p < 0.001; between the survival and the number of days of water warming above 8°С, r Sp = 0.780, p = 0.003; in the Sob River the correlation between the survival and the average daily temperature for 14 days was r Sp = 0.900, p = 0.037. The linear regression equation describing the relationship between the larvae survival rate and the average daily water temperature for 14 days has the following form: y = 0.15 x – 0.35, R 2 = 0.95. It is suggested that the main factor affecting the survival of feeding larvae is the availability of start feed (phytoplankton), the growth of which is determined by the levels of light and water temperature. | Survival of Early Burbot Larvae (Lota lota L., 1758) in the Ob Floodplain | 10.1134/S1067413621060060 |
2021-11-01 | Li-S batteries are considered as a highly promising candidate for the next-generation energy storage system, attributing to their tremendous energy density. However, the two-dimensional island nucleation-growth process of lithium sulfide leads to a thick insulating film covering the electrode, inducing slow electrons transfer and mass-transfer of ions and liquid sulfur species in working Li-S cells. Here, we demonstrate a bio-inspired strategy of constructing ant-nest-like hierarchical porous ultrathin carbon nanosheet networks with the implants of metallic nanoparticles electrocatalysts (HPC-MEC) as efficient nanoreactors enabling rapid mass transfer, via a simple and green NaCl template. Such nanoreactors with a large active surface area could effectively anchor polysulfides for mitigating the shuttle effect, facilitating uniformly thin Li 2 S film, and promoting the mass transfer for fast sulfur species conversions. This helps contribute to a continuously high sulfur utilization in Li-S batteries with the HPC-MEC reactors. As a typical exhibition, cobalt embedded hierarchical porous carbon (HPC-Co) could realize to deliver a remarkably high specific capacity of 1,540.6 mAh·g −1 , an excellent rate performance of 878.8 mAh·g −1 at 2 C, and high area capacity of 11.6 mAh·cm −2 at a high sulfur load of 10 mg·cm −2 and low electrolyte/sulfur ratio of 5 µL·mg −1 . | Bio-inspired construction of electrocatalyst decorated hierarchical porous carbon nanoreactors with enhanced mass transfer ability towards rapid polysulfide redox reactions | 10.1007/s12274-021-3319-x |
2021-11-01 | An on-chip nanopower RC relaxation oscillator is developed in a 180-nm standard CMOS process, consuming 300 nW while running at 10 kHz. Employing a frequency compensation scheme that reduces the frequency drift introduced by comparator offset and delay, the proposed oscillator achieves a significant low temperature coefficient. Furthermore, a supply regulation structure is used to reduce the frequency sensitivity to supply voltage variations. Post-simulation results show that the frequency variation against temperature is 105 ppm/ $$^{\circ }$$ ∘ C in the temperature range from 0 to 85 $$^{\circ }$$ ∘ C, and the line sensitivity is 2.19%/V with the supply voltage changing from 1.05 to 1.45 V. At offset frequencies of 100 Hz and 1 kHz, the simulated phase noises are −50 and −71 dBc/Hz, respectively. | A 300 nW 10 kHz Relaxation Oscillator with 105 ppm/
$$^{\circ }$$
∘
C Temperature Coefficient | 10.1007/s00034-021-01739-0 |
2021-11-01 | Multistage piston compressor units based on low-speed long-stroke stages are considered as a means of compressing gases to high pressures. A theoretical analysis of the influence of the choice of interstage pressures of compressed air on the efficiency of the operation of low-speed stages is presented. It is shown that the principle of distribution of interstage pressures in the compressor under consideration differs significantly from the generally accepted recommendations for high-speed compressors: for multistage reciprocating compressors based on low-speed long-stroke stages, the decisive factor is not the ratio between the discharge and suction pressures, but the magnitude of the difference between them. | Implementation Features of Multistage Compression in Air Compressor Units Based on Low-Speed Long-Stroke Stages | 10.1007/s10556-021-00978-x |
2021-11-01 | An ultra-wideband (12–18 GHz) low-noise amplifier (LNA) using a 65 nm CMOS technology is proposed, in which a common-source cascode structure with capacitive feedback technique is employed, leading to the excellent gain flatness. In order to provide the unconditional stability at all frequencies, a notch filter is placed in the input matching network. The post-layout simulation results confirm the S21 of 11.33 ± 0.33 dB, the input/output return loss of −7.5 to −32.7 dB and −10 to −17 dB, respectively. Moreover, reverse isolation (S12) better than 27 dB, noise figure (NF) of 4.6–5.47 dB and third-order input intercept point (IIP3) of −5.39 to −12.32 dB are obtained over the 12–18 GHz band of interest. The LNA power consumption, excluding the output buffer stage, is only 2.2 mW from a 0.8 V power supply. The LNA layout area is 0.255 mm 2 . | Low-voltage and low-power Ku-band CMOS LNA using capacitive feedback | 10.1007/s10470-021-01922-y |
2021-11-01 | Abstract Chromium is one of the most hazardous inorganic water pollutants which is constantly released into water resources by natural and industrial processes. Microfiltration membranes (with pore sizes between 0.1–10 μm) cannot separate chromium ions and hence nanofiltration membranes (with pore sizes between 0.5–2 nm) are necessary which need high pressure pumps. Using adsorptive membranes, i.e. membranes which can adsorb impurities without using any extra adsorptive particles, is a new and developing method for water treatment which can be considered as a combination of adsorption and membrane technology. In this paper, clay-based adsorptive microfiltration membranes were successfully synthesized for chromium removal from water. 80 wt % of bentonite and 20 wt % of carbonates (calcium, magnesium and their mixture) were mixed, uniaxially pressed, dried, and fired at 1100°C for 3 h. Then, phase analyses of the samples, their physical and mechanical properties, microstructure, mean pore size and also their ability for chromium removal from water were studied. Results showed that the addition of carbonates lead the porosity to increase while contrary to organic pore formers like starch, due to the formation of phases like wollastonite, the mechanical strength not only didn’t collapse but also improved. It was seen that Cr 3+ ions were removed from water up to 95% and regarding that the mean pore sizes of the microfiltration membranes used in this work (0.6–2.5 μm) were 10 000 times bigger than the size of Cr 3+ ions (0.615 A), it was deduced that Cr 3+ ions were removed through adsorption mechanism and the microfiltration membrane prepared the media for adsorption. By analyzing the filtered water and observation of Ca 2+ ions in it, it was concluded that ion exchange was the main mechanism. Hence, a combination of membrane filtration and adsorption was achieved for water treatment which made microfiltration membranes act as nanofiltration ones and considering that the concentration of Cr 3+ ions in real drinking water resources is less than 5 ppm (which is regarded in this research), it can be said that these low-cost adsorptive microfiltration membranes can be used to gain high quality drinking water. | Synthesis of Clay-Based Adsorptive Microfiltration Membranes | 10.3103/S1063455X21060047 |
2021-11-01 | Abstract A nearly saturated 2,2,2-trifluoroethyl acetate (FEA)-based electrolyte solution has a low viscosity and delivers superior charge/discharge performance for LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) positive electrodes for lithium ion batteries. However, FEA has a low flash point, and hence needs to be mixed with an appropriate co-solvent to improve the safety of electrolyte solutions. In this study, two kinds of co-solvent were introduced into LiBF 4 /FEA electrolyte solutions and the LiBF 4 concentration was increased. The mixture ratio of FEA and a co-solvent had a major effect on the charge/discharge performance of NCM811. The resultant nearly saturated electrolyte solution further improved the charge/discharge properties in terms of both cycle- and high rate performance. A very thin protective layer formed on NCM811 to suppress continual decomposition of the electrolyte solution, and did not interfere with interfacial Li + transfer between the NCM811 electrode and electrolyte solution. In addition, 2,2-difluoroethyl acetate, which has a higher flash point than FEA, was used as a main solvent to study the highly concentrated electrolyte solutions. Graphic abstract | Improved stability of highly concentrated LiBF4/fluorinated ethyl acetate-based electrolyte solutions with a co-solvent for LiNi0.8Co0.1Mn0.1O2 positive electrodes in lithium ion batteries | 10.1007/s10800-021-01590-w |
2021-11-01 | In this paper, the authors have developed a new device and method for measuring the efficiency of spontaneous imbibition and displacement in a low permeability reservoir. The innovative design of the new experimental device effectively combines the traditional volumetric method and the weighing method. The improved reliability of experimental results is provided by the mutual verification of data of the two conventional techniques. The performance and effectiveness of the new method and the device have been verified by experimental tests on a low-permeability core. The results can be useful for understanding the self-priming oil displacement efficiency in a low permeability reservoir. | Device and Method for Measuring the Efficiency of Spontaneous Imbibition and Displacement in a Low-Permeability Reservoir | 10.1007/s10553-021-01315-x |
2021-11-01 | Abstract The spatial relationships of the lower mantle D" layer elements with Phanerozoic Large Igneous Provinces (LIPs), as well as with the young hotspots and kimberlites in the African region, are discussed. Similar relationships are also shown for the Cape Karoo and Parana extended basins, which had developed as inherited structures along the marginal parts of the region since the Early Paleozoic. The specific locations are marked for all these superficial structures and plumes producing them. These locations indicate the connection between these structures origin and the domains where the Earth’s core, Large Low-Velocity Provinces (LLSVPs), and slab graveyards contact with each other. The relationships between plume- and plate-tectonic processes in the Earth’s evolution are considered. Constant interaction between the Pacific and Indo-Atlantic segments of the Earth is revealed in the course of these processes. The Pacific segment was characterized by ocean formation during the Phanerozoic time and subsequent subduction under the continental landmasses of Indo-Atlantic segment. The constant character of spreading in the Pacific Ocean was obviously determined by the presence of its direct connection with the Pacific LLSVP. Within the D" layer in the areas of contact between the Pacific subducting slabs and African LLSVP, plume generation occurred periodically, subsequently leading to supercontinental breakup. This determined the specific character of the Indo-Atlantic segment development: the alternation of convergence and continental breakup during the Phanerozoic. In general, despite the significant similarities between the antipodal African and Pacific LLSVPs, their role in formation of the superficial largest structural elements appears to be inequable. Perhaps this is what had become one of the main reasons that caused fundamental differences between these two segments and led to the formation of tectonic asymmetry of the Earth. | Relationship between Superficial and Deep Tectonics in the African Region Based on Geological–Geophysical Data | 10.1134/S0016852121060054 |
2021-11-01 | Abstract The geological, petrographic, and geochemical features detected in the Upper Pliocene acid volcanic rocks sampled in the Upper Chegem and Lower Chegem volcanic highlands provide evidence that the Upper Chegem volcanic rocks are not tuffs that have been subaerially transported from the Upper Chegem Highland; they came from several local centers. These results are in contradiction with the hypothesis of a pyroclastic origin for most Upper Pliocene acid volcanic rocks that compose the bulk of the Upper Chegem volcano-tectonic basin. These volcanic rocks are hypothesized to have resulted from the effusion of mobile lava flows. The overwhelming majority of the Lower Chegem, Upper Pliocene, acid volcanic rocks are of a pyroclastic origin, being among other formative factors due to precipitation and subsequent welding of material from short pyroclastic flows. | Upper Pliocene Acid Volcanic Rocks in the Upper Chegem and Lower Chegem Volcanic Highlands, North Caucasus | 10.1134/S0742046321060075 |
2021-11-01 | The decades-old idea of electric-powered commercial flight has re-emerged alongside high expectations for greener CO 2 emission-free air transportation. But to what extent can electric aircraft reduce the energy and environmental footprint of aviation? What should such aircraft look like, and how does their operation compare to conventional jet aircraft? What technologies are needed and which of them are already in place? This paper goes back to the basics of flight physics and critically analyzes some of the unresolved challenges that lay ahead. Current commercial operations are examined and the short-term effects of any electrification of short-range flights are quantified. Fundamental system components and basic design and operating concepts are analysed to highlight unavoidable constraints that often seem to be misunderstood or overlooked. These limitations are illustrated with a conceptual study of a full-electric FAR/CS-23 commuter aircraft and realistic estimations of its performance. It becomes clear that electric propulsion alone will not fully meet society’s expectations, even if key enabling technologies continue to develop as forecast. Nevertheless, this paper suggests that electrification may instead become one piece of a propulsion-technology mix that would more effectively address our short- and long-term emission goals. | The potential of full-electric aircraft for civil transportation: from the Breguet range equation to operational aspects | 10.1007/s13272-021-00530-w |
2021-11-01 | Coastal nutrient pollution is an ever-present threat to estuaries worldwide. Benthic denitrification has been identified as a crucial ecosystem service to help mitigate increasing N loads to the coast. However, the controls on denitrification in low-nutrient systems are not well constrained and are likely different to those in more widely studied eutrophic systems. This study aims to identify the specific controls on denitrification in low-nutrient estuaries, including the contribution of the macrofaunal community to denitrification rates, and to understand how this important service fits into the network of ecogeochemical processes in these systems. Results show that porewater ammonium concentrations and mud content are good predictors of net N 2 flux in the dark. Additionally, models predict N 2 flux rates much more effectively in the dark than in the light, but the macrofaunal community data, specifically species richness, is a key factor in both increasing the explanatory power of both models by nearly 20%. Additionally, interaction networks reveal that increasing mud content results in a shift in the macrofaunal community and a reduction in the N removal capacity of these intertidal systems. | Ecogeochemistry and Denitrification in Non-eutrophic Coastal Sediments | 10.1007/s12237-021-00912-7 |
2021-11-01 | The importance of studying the atmospheric pollution due to its effects on human health and other ecosystems, the inexistence of national production of equipment for air sample collection, and the high cost of the imported equipment (especially in developing countries) led the authors of the present work to construct a low-cost Gent type sampler. The construction of the sampler was carried out by combining low-cost materials with good mechanical strength (such as nylon 6.0), hydraulic piping PVC, and the use of a 3D printer. The innovation of the present work is the employment of a 3D printer using ABS polymer to create the grids that cannot be machined. In addition to the sampler, the system is composed of a vacuum pump, a gas meter, and a rotameter. The total cost of the sampling system amounted at about 1200 USD, and the cost of the manufactured Gent type sampler did not reach 100 USD. The results obtained while using this set for sampling atmospheric aerosol for a period of 11 months were compared with the mass concentration of PM 10 obtained from the official environmental company, CETESB of São Paulo State, Brazil, showing good correlation with those from CETESB — which confirmed its effectiveness and suitability for use. The low cost, easy operation, and versatility of the built Gent type sampler enable its use for scientific and academic purposes. The equipment can be useful in environmental monitoring networks, in low-income regions, and as an instrument for environmental education used in universities. Graphical abstract | Low-cost Gent type sampler constructed for urban atmospheric aerosol sampling | 10.1007/s11356-020-12103-1 |
2021-11-01 | Abstract Objective Organic acids have a wide range of applications and have attracted the attention of many industries, and their large-scale applications have led fermentation production to low-cost development. Among them, the microbial fermentation method, especially using Escherichia coli as the production host, has the advantages of fast growth and low energy consumption, and has gradually shown better advantages and prospects in organic acid fermentation production. Importance However, when the opportunity comes, the acidified environment caused by the acid products accumulated during the fermentation process also challenges E. coli . The acid sensitivity of E. coli is a core problem that needs to be solved urgently. The addition of neutralizers in traditional operations led to the emergence of osmotic stress inadvertently, the addition of strong acid substances to recover products in the salt state not only increases production costs, but the discharged sewage is also harmful to the environment. Elaboration This article summarizes the current status of the application of E. coli in the production of organic acids, and based on the impact of acid stress on the physiological state of cells and the impact of industrial production profits, put forward some new conjectures that can make up for the deficiencies in existing research and application. Implication At this point, the diversified transformation of E. coli has become a chassis microbe that is more suitable for industrial fermentation, enhancing industrial application value. Key points • E. coli is a potential host for high value-added organic acids production. • Classify the damage mechanism and coping strategies of E. coli when stimulated by acid molecules. • Multi-dimensional expansion tools are needed to create acid-resistant E. coli chassis. | The challenges and prospects of Escherichia coli as an organic acid production host under acid stress | 10.1007/s00253-021-11577-4 |
2021-11-01 | EU has set ambitious commitment to achieve low carbon energy and economy transition up to 2050. This low carbon transition means sustainable energy development path based on renewable energy sources and first of all should address the energy poverty vulnerability and justice issues. The main goal of the paper is to develop indicators framework for assessing low carbon just energy transition and to apply this framework for analysis how climate change mitigation policies in households targeting enhancement of energy renovation of residential buildings and promotion of the use of micro-generation technologies and other policies are affecting household’s energy poverty and vulnerability in selected countries: Lithuania and Greece. This framework allows to assess three main dimensions of sustainable energy development: environmental, social and economic. The paper provides policy recommendations how to deal with just low carbon energy transition which means addressing energy poverty issues during moving to 100% renewables in power generation based on performed case studies. | Energy Poverty and Low Carbon Just Energy Transition: Comparative Study in Lithuania and Greece | 10.1007/s11205-021-02685-9 |
2021-11-01 | Abstract The existing approaches to bioisobutanol synthesis and commercial production are considered. Ways of using bioisobutanol as a component of motor fuel and as a promising feedstock for the production of “green” hydrocarbons and other petrochemicals that favor the progress of low-carbon economy are discussed. Particular attention is paid to catalytic processes of isobutanol conversion to isobutylene and butenes, aromatic hydrocarbons, C 2 –С 4 olefins, and hydrogen-containing gases. Data on the mechanism of isobutanol transformations on zeolite catalysts are given. | Bioisobutanol as a Promising Feedstock for Production of “Green” Hydrocarbons and Petrochemicals (A Review) | 10.1134/S0965544121110165 |
2021-11-01 | The aim of this study was to compare peloid therapy in addition to home exercise with home exercise alone in terms of pain, function, quality of life, and depression in patients with chronic low back pain (cLBP). A total of 106 cLBP patients were divided into two equal groups as treatment and control. The peloid therapy group had peloid therapy (with a total of 15 sessions on 5 days per week for 3 weeks duration with 45 °C temperature lasting 30 min/day) + home exercise program. The control group was only given a home exercise program. Patients completed the visual analog scale-pain (VAS-pain), patient and physician global assessments (VAS-PGA and VAS-PhGA), revised Oswestry disability index (rODI) for functional status, the short form-36 (SF-36) for quality of life, and Beck Depression Inventory (BDI) for depression three times as before treatment, after treatment (3rd week), and 1 month after the end of treatment. Assessments in the 3rd week at the end of treatment revealed statistically significant improvements for rODI ( p = 0.013), VAS-pain ( p = 0.039), and VAS-PhGA ( p = 0.002) parameters in the peloid therapy group compared to the control group. Assessments in the 1st month after the end of treatment revealed statistically significant improvements in rODI ( p < 0.001), VAS-pain ( p < 0.001), VAS-PGA ( p = 0.002), VAS-PhGA ( p < 0.001), and SF-36VE ( p = 0.022) parameters in the peloid therapy group compared to the control group. Peloid therapy + home exercise was statistically significantly superior to home exercise alone in improving pain and function in patients with cLBP. Peloid therapy may be recommended as a non-pharmacological treatment for cLBP patients. There is a need for randomized studies with longer follow-up including biochemical parameters to verify the beneficial effects observed in this study and elaborate the mechanisms of action. | Effectiveness of peloid therapy in patients with chronic low back pain: a single-blind controlled study | 10.1007/s00484-021-02137-6 |
2021-11-01 | Abstract The Qianjiadian (QJD) uranium ore field, located in the southwest of the Songliao Basin of east China, was discovered within the red-variegated depositional layer of the Upper Cretaceous Yaojia Formation (Fm). It preformed some particular and complex characteristics in respect of the occurrence location, ore-hosting strata, alteration, and morphology of the ore body, compared with the sedimentary uranium deposit generated in the traditional dark coal-bearing clastic strata. In this study, the categories of organic matter (OM) within the Lower Member of Yaojia Fm (LYF), and their effects on the rock alteration and uranium mineralization process, were researched macro-microscopically. The aim of the study was to confirm the co-associated relationships between the gray layer, rock-faded zone, and tabular-shaped ore body, in addition to their genesis. Results showed that the OM mainly consists of synsedimentary carbonaceous detritus (kind-I), amorphous movable humic substances (kind-II), and deep-originated hydrocarbon fluid (kind-III), which widely led to rock-bleaching, green alteration, and different forms of pyritization and carbonation throughout the geological history. OMs of kind-I and kind-II were inherited from terrigenous higher plants, and did not directly adsorb and bio-reduce hexavalent uranyl ions during the metabolic processes of sulfate reducing bacteria (SRB), but indirectly promoted uranium precipitation related to a H 2 S-rich secondary reducing barrier, produced by bacterial sulfate reduction (BSR) and the pyrolysis of the diabase dikes. III-OM was derived from deep reservoirs and exhibited multiple positive effects of increasing the reduction capacity of the primary weak reducing strata, and protecting and enriching the earlier ores. Uranium in the ores is mainly composed of pitchblende, followed by a small amount of coffinites and uranium-bearing titanium minerals. Combined with the geological setting of the QJD ore field, a six-stage ore-forming model for the LYF was constructed from the perspective of the reducing medium, i.e., (1) development of ore-bearing sand-bodies in the Yaojia Fm period; (2) formation of a tabular grey layer before the Nenjing Fm period; (3) initial bleaching and uranium pre-concentration during the diagenetic period; (4) initial mineralization and hydrocarbon reduction from the end of the Nenjing period to the end of the Mingshui period; (5) main mineralization and thermal transformation in the Paleogene period; and (6) superimposed mineralization in the Neogene period. The proposed new model does not enrich the uranium metallogenic mechanism for the red-variegated bed, but plays a key role in guiding the uranium prospecting for similar red beds, both in the Songliao Basin and in other sedimentary basins globally. | Characteristics and Genesis of Organic Matter within the Lower Member of Yaojia Formation and its Implications for Tabular-type Uranium Deposits in the Southwest of Songliao Basin | 10.1134/S1075701521310019 |
2021-11-01 | Due to the rapid economic development and acceleration of industrialization, most cities in China are experiencing severe air pollution. Exposure to fine particulate matter (PM 2.5 ) has been associated with acute lower respiratory tract infection (ALRI). To estimate associations between short-term exposure to PM 2.5 and ALRI hospitalization in Yancheng City, China. This was a 6-year time-series study from 2014 to 2019. Data on hospitalization were collected from four high-ranked general hospitals, including for community-acquired pneumonia (CAP), acute exacerbation of chronic bronchitis (AECB), acute exacerbation of chronic obstructive pulmonary disease (AECOPD), and acute exacerbation of bronchiectasis (AEB), and the sum was termed total ALRIs. We obtained pollutant exposure data from five fixed monitoring stations. The association between PM 2.5 and ALRI hospitalization was estimated using the generalized linear model with quasi-Poisson regression. Two-pollutant models were applied to test the robustness of the observed correlations. Subgroup analyses included sex, age, and season. During the study period, a total of 43,283 cases of total ALRIs were recorded. The average annual mean PM 2.5 concentration was 45.4 ± 32.3 μg/m 3 . A 10-μg/m 3 increase in PM 2.5 concentration (lag 0) was significantly associated with increases in hospitalizations for total ALRIs (at 0.73%; 95% CI: 0.40%, 1.06%), in CAP (at 0.80%; 95% CI: 0.02%, 1.57%), in for AECOPD (1.08%; 95% CI: 0.38%, 1.78%), and AECB (0.67%; 95% CI: 0.23%, 1.11%). The estimated effects for total ALRIs and AECB were relatively robust with adjustment for other air pollutants. Associations between PM 2.5 and total ALRIs were stronger in females, in the elderly, and in the cold season. PM 2.5 exposure was significantly associated with ALRI morbidity, and females and older people were more susceptible to PM 2.5 air pollution, especially in the cold season. | The association between fine particulate matter and acute lower respiratory infections in Yancheng City, China | 10.1007/s11356-021-15102-y |
2021-11-01 | Purpose To evaluate the efficacy and safety of lung low-dose radiation therapy (LD-RT) for pneumonia in patients with coronavirus disease 2019 (COVID-19). Materials and methods Inclusion criteria comprised patients with COVID-19-related moderate–severe pneumonia warranting hospitalization with supplemental O 2 and not candidates for admission to the intensive care unit because of comorbidities or general status. All patients received single lung dose of 0.5 Gy. Respiratory and systemic inflammatory parameters were evaluated before irradiation, at 24 h and 1 week after LD-RT. Primary endpoint was increased in the ratio of arterial oxygen partial pressure (PaO 2 ) or the pulse oximetry saturation (SpO 2 ) to fractional inspired oxygen (FiO 2 ) ratio of at least 20% at 24 h with respect to the preirradiation value. Results Between June and November 2020, 36 patients with COVID-19 pneumonia and a mean age of 84 years were enrolled. Seventeen were women and 19 were men and all of them had comorbidities. All patients had bilateral pulmonary infiltrates on chest X‑ray. All patients received dexamethasone treatment. Mean SpO 2 pretreatment value was 94.28% and the SpO 2 /FiO 2 ratio varied from 255 mm Hg to 283 mm Hg at 24 h and to 381 mm Hg at 1 week, respectively. In those who survived (23/36, 64%), a significant improvement was observed in the percentage of lung involvement in the CT scan at 1 week after LD-RT. No adverse effects related to radiation treatment have been reported. Conclusions LD-RT appears to be a feasible and safe option in a population with COVID-19 bilateral interstitial pneumonia in the presence of significant comorbidities. | Could pulmonary low-dose radiation therapy be an alternative treatment for patients with COVID-19 pneumonia? Preliminary results of a multicenter SEOR-GICOR nonrandomized prospective trial (IPACOVID trial) | 10.1007/s00066-021-01803-3 |
2021-11-01 | Low-grade fibromyxoid sarcoma (LGFMS) is a rare soft-tissue sarcoma genetically characterized by the presence of the FUS-CREB3L2 gene fusion. While LGFMS exhibits indolent features during its early stages, the rates of recurrence, metastasis, and death from the disease are high. Presently, the role of FUS-CREB3L2 gene fusions in the unique features of LGFMS is not clear, and there is no modality to improve the clinical outcomes of patients with LGFMS; thus, extensive studies on LGFMS are required. Patient-derived cancer cell lines are critical tools for cancer research. However, no cell line has been established for LGFMS. Here, we aimed to develop a novel cell line for LGFMS and successfully established it using surgically resected tumor tissues. The cells, named NCC-LGFMS1-C1, possessed the same fusion genes as their original tumor and visible copy number variations. The cells had a fibroblastic appearance, formed spheroids when they were seeded in a low-attachment dish, and exhibited constant growth and invasion. Additionally, we demonstrated the feasibility of high-throughput drug screening using these cells. In conclusion, the NCC-LGFMS1-C1 cell line is a useful tool for studying LGFMS. | Establishment and characterization of NCC-LGFMS1-C1: a novel patient-derived cell line of low-grade fibromyxoid sarcoma | 10.1007/s13577-021-00612-1 |
2021-11-01 | Abstract The results of studies on the use of solid-state infrared lasers in combination with special targets for obtaining primary electrons in ionization chambers of plasma-ion thrusters are presented. Such thrusters being equipped with free molecular air intakes for using the surrounding atmosphere as a propellant for air-breathing electric thrusters, which are highly efficient for long-term maintenance of spacecraft in ultra-low orbits, providing significant advantages in Earth remote sensing and telecommunications. It is shown that the method of electron emission proposed can be an alternative to the current-heated cathodes used today, significantly increasing their lifetime. | Prospects of Infrared Lasers in Air-Breathing Electric Thrusters | 10.1134/S1028335821110045 |
2021-11-01 | It is of necessity to investigate the adjustment of flood discharge capacity in the Lower Yellow River (LYR) because of its profound importance in sediment transport and flood control decision-making, and additionally its magnitude is influenced by the channel and upstream boundary conditions, which have significantly varied with the ongoing implementation of soil and water conservation measures in the Loess Plateau and the operation of the Xiaolangdi Reservoir. The braided reach between two hydrometric stations of Huayuankou and Gaocun in the LYR was selected as the study area. Different parameters in the study reach during the period 1986–2015 were calculated, covering bankfull discharge (the indicator of flood discharge capacity), the pre-flood geomorphic coefficient (the indicator of channel boundary condition), and the previous five-year average fluvial erosion intensity during flood seasons (the indicator of incoming flow and sediment regime). Functional linkages at scales of section and reach were then developed respectively to quantitatively demonstrate the integrated effects of channel and upstream boundary conditions on the flood discharge capacity. Results show that: (1) the reach-scale bankfull discharge in the pre-dam stage (1986–1999) decreased rapidly by 50%, accompanied with severe channel aggradation and main-channel shrinkage. It recovered gradually as the geometry of main channel became narrower and deeper in the post-dam stage, with the geomorphic coefficient continuously reducing to less than 15 m −1/2 . (2) The response of bankfull discharge to the channel and upstream boundary conditions varied at scales of section and reach, and consequently the determination coefficients differed for the comprehensive equations, with a smallest value at the Jiahetan station and a highest value (0.91) at reach scale. Generally, the verified results calculated using the comprehensive equations agreed well with the corresponding measured values in 2014–2015. (3) The effect of channel boundary condition was more prominent than that of upstream boundary condition on the adjustment of bankfull discharge at the Jiahetan station and the braided reach, which was proved by a larger improvement in determination coefficients for the comprehensive equations and a better performance of geomorphic coefficient on the increase of bankfull discharge. | Adjustment of flood discharge capacity with varying boundary conditions in a braided reach of the Lower Yellow River | 10.1007/s11442-021-1914-0 |
2021-11-01 | Abstract An unsteady heat conduction problem is studied in a plane consisting of two half-planes filled with different inhomogeneous materials with exponential internal thermal conductivities. It is assumed that there is a crack at the boundary of the half-planes, i.e., inhomogeneous transmission conditions are set. In the upper and lower half-planes, the heat equations are supplemented with conditions on the differences between the temperatures and heat fluxes in the upper and lower crack faces. Homogeneous initial conditions are specified. Integral representations for the components of the solution to the problem are presented, and the boundary and initial conditions are proved to hold. For the solution to the problem, after making a change of variables, even continuations of the studied functions to the upper half-plane are constructed. The problem is reduced to a generalized one. The Fourier transform with respect to space variables and the Laplace transform with respect to time are applied to the latter problem, so that the properties of these transforms can be used to obtain the solution. Integral representations of the solution to the original problem are found using the inverse transforms. This paper is the first of two addressing this subject. In the second work, we intend to construct singular components of asymptotic expansions of the solution with respect to the distance to the interface line. | Unsteady Heat Conduction Problem for a Plane with a Crack at the Interface between Two Inhomogeneous Materials | 10.1134/S0965542521110075 |
2021-11-01 | Purpose Globally planned surgical procedures have been deferred during the current COVID-19 pandemic. The study aimed to report the outcomes of planned urgent and cancer cases during the current pandemic using a multi-disciplinary prioritisation group. Methods A prospective cohort study of patients having urgent or cancer surgery at a NHS Trust from 1st March to 30th April 2020 who had been prioritised by a multi-disciplinary COVID Surgery group. Rates of post-operative PCR positive and suspected COVID-19 infections within 30 days, 30-day mortality and any death related to COVID-19 are reported. Results Overall 597 patients underwent surgery with a median age of 65 years (interquartile range (IQR) 54–74 years). Of these, 86.1% (514/597) had a current cancer diagnosis. During the period, 60.8% (363/597) of patients had surgery at the NHS Trust whilst 39.2% (234/597) had surgery at Independent Sector hospitals. The incidence of COVID-19 in the East Midlands was 193.7 per 100,000 population during the study period. In the 30 days following surgery, 1.3% (8/597) of patients tested positive for COVID-19 with all cases at the NHS site. Overall 30-day mortality was 0.7% (4/597). Following a PCR positive COVID-19 diagnosis, mortality was 25.0% (2/8). Including both PCR positive and suspected cases, 3.0% (18/597) developed COVID-19 infection with 1.3% at the independent site compared to 4.1% at the NHS Trust ( p =0.047). Conclusions Rates of COVID-19 infection in the post-operative period were low especially in the Independent Sector site. Mortality following a post-operative diagnosis of COVID-19 was high. | Planned surgery in the COVID-19 pandemic: a prospective cohort study from Nottingham | 10.1007/s00423-021-02207-8 |
2021-11-01 | Background Laparoscopic surgery is regarded as the gold standard for the surgical management of cholelithiasis. To improve post-operative pain, low-pressure laparoscopic cholecystectomies (LPLC) have been trialed. A recent systematic review found that LPLC reduced pain; however, many of the randomised control trials were at a high risk of bias and the overall quality of evidence was low. Methods One hundred patients undergoing elective laparoscopic cholecystectomy were randomised to a LPLC (8 mmHg) or a standard pressure laparoscopic cholecystectomy (12 mmHg) (SPLC) with surgeons and anaesthetists blinded to the pressure. Pressures were increased if vision was compromised. Primary outcomes were post-operative pain and analgesia requirements at 4–6 h and 24 h. Results Intra-operative visibility was significantly reduced in LPLC ( p <0.01) resulting in a higher number of operations requiring the pressure to be increased (29% vs 8%, p =0.010); however, there were no differences in length of operation or post-operative outcomes. Pain scores were comparable at all time points across all pressures; however, recovery room fentanyl requirement was more than four times higher when comparing 8 to 12 mmHg (12.5mcg vs 60mcg, p =0.047). Nausea and vomiting was also higher when comparing these pressures (0/36 vs 7/60, p =0.033). Interestingly, when surgeons estimated the operating pressure, they were correct in only 69% of cases. Conclusion Although pain scores were similar, there was a significant reduction in fentanyl requirement and nausea/vomiting in LPLC. Although LPLC compromised intra-operative visibility requiring increased pressure in some cases, there was no difference in complications, suggesting LPLC is safe and beneficial to attempt in all patients. Trial Registration Registered with the Australia and New Zealand Clinical Trials Registry (ACTRN12619000205134). | Reduced Laparoscopic Intra-abdominal Pressure During Laparoscopic Cholecystectomy and Its Effect on Post-operative Pain: a Double-Blinded Randomised Control Trial | 10.1007/s11605-021-04919-0 |
2021-11-01 | Low-latency and energy-efficient multi-Gbps LDPC decoding requires fast-converging iterative schedules. Hardware decoder architectures based on such schedules can achieve high throughput at low clock speeds, resulting in reduced power consumption and relaxed timing closure requirements for physical VLSI design. In this work, a fast column message-passing (FCMP) schedule for decoding LDPC codes is presented and investigated. FCMP converges in half the number of iterations compared to existing serial decoding schedules, has a significantly lower computational complexity than residual-belief-propagation (RBP)-based schedules, and consumes less power compared to state-of-the-art schedules. An FCMP decoder architecture supporting IEEE 802.11ad (WiGig) LDPC codes is presented. The decoder is fully pipelined to decode two frames with no idle cycles. The architecture is synthesized using the TSMC 40 nm and 65 nm CMOS technology nodes, and operates at a clock-frequency of 200 MHz. The decoder achieves a throughput of 8.4 Gbps, and it consumes 72 mW of power when synthesized using the 40 nm technology node. This results in an energy efficiency of 8.6 pJ/bit, which is the best-reported energy-efficiency in the literature for a WiGig LDPC decoder. | Fast-Converging and Low-Power LDPC Decoding: Algorithm, Architecture, and VLSI Implementation | 10.1007/s11265-021-01680-0 |
2021-10-30 | Main conclusion Soybean phosphorous efficiency QTLs were identified and candidate genes were predicted using chlorophyll fluorescence parameters through GWAS and RNA-seq. Abstract Phosphorus (P) is an essential nutrient element for crop growth and development, lack of P uptake seriously affects yield in various crops. Photosynthesis is the basis of crop production, while it is very sensitive to P deficiency. It is of great importance to study the genetic relationship between photosynthesis and P efficiency to provide genetic insight for soybean improvement. In this study, a genome-wide association study (GWAS) was performed using 292,035 SNPs and the ratios of four main chlorophyll fluorescence parameters of 219 diverse soybean accessions under P deficiency and normal P across three experiments. In total, 52 SNPs in 12 genomic regions were detected in association with the four main chlorophyll fluorescence parameters under sufficient or deficient P levels. Combined it with RNA-seq analysis, we predicted three candidate genes for the significant genomic regions. For example, the expression level of the candidate gene ( Glyma.18g092900 ) in P deficiency tolerant accession was three times higher than that of P deficiency sensitive one under phosphorous deficiency condition. This study provides insight into genetic links between photosynthetic and phosphorous efficiency and further functional analysis will provide valuable information for understanding the underlying genetic mechanism to facilitate marker-assisted breeding in soybean. | Identification of soybean phosphorous efficiency QTLs and genes using chlorophyll fluorescence parameters through GWAS and RNA-seq | 10.1007/s00425-021-03760-8 |
2021-10-28 | Background Histone methylation occurs primarily on lysine residues and requires a set of enzymes capable of reading, writing, and erasing to control its establishment and deletion, which is essential for maintaining chromatin structure and gene expression. Histone methylation and demethylation are contributed to plant growth and development, and are involved in adapting to environmental stresses. The JmjC domain-containing proteins are extensively studied for their function in histone lysine demethylation in plants, and play a critical role in sustaining histone methylation homeostasis. Results In this study, a total of 21 JmjC domain-containing histone demethylase proteins (JHDMs) in birch were identified and classified into five subfamilies based on structural characteristics and phylogenetic relationships among Arabidopsis, rice, maize, and birch. Although the BpJMJ genes displayed significant schematic variation, their distribution on the chromosomes is relatively uniform. Additionally, the BpJMJ genes in birch have never experienced a tandem-duplication event proved by WGD analysis and were remaining underwent purifying selection (Ka/Ks < < 1). A typical JmjC domain was found in all BpJMJ genes, some of which have other essential domains for their functions. In the promoter regions of BpJMJ genes, cis-acting elements associated with hormone and abiotic stress responses were overrepresented. Under abiotic stresses, the transcriptome profile reveals two contrasting expression patterns within 21 BpJMJ genes. Furthermore, it was established that most BpJMJ genes had higher expression in young tissues under normal conditions, with BpJMJ06/16 having the highest expression in germinating seeds and participating in the regulation of BpGA3ox1/2 gene expression. Eventually, BpJMJ genes were found to directly interact with genes involved in the “intracellular membrane” in respond to cold stress. Conclusions The present study will provide a foundation for future experiments on histone demethylases in birch and a theoretical basis for epigenetic research on growth and development in response to abiotic stresses. | Genome-wide identification, classification, and expression analysis of the JmjC domain-containing histone demethylase gene family in birch | 10.1186/s12864-021-08063-6 |
2021-10-27 | The first melatonergic antidepressant drug, agomelatine (AGM), is commonly used for controlling major depressive disorders. AGM suffers low (< 5%) oral bioavailability owing to the hepatic metabolism. The current work investigated the potential of low-frequency sonophoresis on enhancing transdermal delivery of AGM-loaded novasomes and, hence, bioavailability of AGM. Drug-loaded novasomes were developed using free fatty acid (stearic acid or oleic acid), surfactant (span 60 or span 80), and cholesterol via thin-film hydration technique. The systems (N1-N16) were assessed for zeta potential (ZP), particle size (PS), encapsulation efficiency (EE%), and drug percent released after 0.5 h ( Q 0.5 h ) and 8 h ( Q 8h ), drug-crystallinity, morphology, and ex vivo drug permeation. Skin pre-treatment with low-frequency ultrasound (LFU) waves, via N13-novasomal gel systems, was optimized to enhance ex vivo drug permeation. Influences of LFU mode (continuous or pulsed), duty cycle (50% or 100%), and application period (10 or 15 min) were optimized. The pharmacokinetics of the optimized system (N13-LFU-C4) was assessed in rabbits. N13 was the best achieved novasomal system with respect to PS (471.6 nm), ZP (− 63.6 mv), EE% (60.5%), Q 0.5 h (27.8%), Q 8h (83.9%), flux (15.5 μg/cm 2 /h), and enhancement ratio (6.9). N13-LFU-C4 was the optimized novasomal gel system (desirability; 0.997) which involves skin pre-treatment with LFU in a continuous mode, at 100% duty cycle, for 15 min. Compared to AGM dispersion, the significantly ( P < 0.05) higher flux (26.7 μg/cm 2 /h), enhancement ratio (11.9), C max (118.23 ng/mL), and relative bioavailability (≈ 8.6 folds) could elucidate the potential of N13-LFU-C4 system in improving transdermal drug permeability and bioavailability. | Low-Frequency Sonophoresis as an Active Approach to Potentiate the Transdermal Delivery of Agomelatine-Loaded Novasomes: Design, Optimization, and Pharmacokinetic Profiling in Rabbits | 10.1208/s12249-021-02147-y |
2021-10-26 | Background Silages, as a nutritious and long-term preserved fodder, is achieved through fermentation. However, the constant low temperatures and freeze–thaw event are key factors that affect the quality of silages due to low levels of lactic acid production and undesirable microbial community revitalization. In this study, we attempt to investigate the effects of Lactobacillus plantarum QZW5 on the fermentation characteristics of wheat silage under ensiling conditions at the order of the following temperatures: constant low temperatures (5 °C for 30 days), multigelation (10 ℃ at day and – 10 ℃ at night for 30 days) and room temperature (aerobic/anaerobic, 10 days). Results Under multigelation condition, Lactobacillus plantarum QZW5 inoculation significantly increased the contents of lactic acid and acetic ( P < 0.05) in the silage. The pH, bacterial richness index (Chao) and diversity index (Shannon) of the silage were significantly decreased by Lactobacillus plantarum QZW5 ( P < 0.05). In Lactobacillus plantarum QZW5 inoculated silage, the dominant genera were L. plantarum subsp. plantarum . However, those in the control silage were Leuconostoc mesenteroides and Leuconostoc fallax . LAB (lactic acid bacteria) inoculation increased the abundance of desirable Lactobacillus spp. and inhibited the growth of undesirable Escherichia coli , Saccharomyces cerevisiae , and Filamentous fungi , among others in the silage. Conclusions Therefore, inoculation of L. plantarum QZW5 during ensiling could stimulate favorable fermentation and reconstruct bacterial community for better silage preservation. Graphic abstract | Characteristics of Lactobacillus plantarum QZW5 and its effects on wheat silage under multigelation | 10.1186/s40538-021-00251-6 |
2021-10-25 | Removal of excessive sulfate from the low-temperature groundwater environment in the Longdong area is important for protecting human health. The effects of naturally occurring hydrochemical ions and pH on sulfate adsorption were examined to verify the applicability of magma-derived scoria and determine whether scoria could be reused. Hydrochemical ions and pH of the natural groundwater environment in the study area improved the adsorption capabilities of scoria for sulfate. Additionally, 2% AlCl 3 was sufficiently stable for use as a high-efficiency regenerant for sulfate desorption from the scoria. The adsorption characteristics of scoria were determined using a continuous dynamic column system. The effects of flow rate, initial sulfate concentration, and column height on breakthrough curves were investigated at low temperatures. The scoria adsorption capacity increased with increasing sulfate initial concentrations and decreased with increasing flow rates and column heights. The maximum adsorption capacity was 10.14 mg/g at a flow rate of 5 mL/min, initial concentration of 500 mg/L, and column height of 10 cm. The breakthrough time increased with increasing column heights and decreased with increasing flow rates and initial concentrations. Model comparison to analyze adsorption kinetics showed that the Bohart–Adams model is an excellent fit for the dynamic experimental data. Electron microscopy and spectroscopy methods confirmed the surface changes before and after adsorption. Thus, scoria is a highly efficient, economical, and environmentally friendly adsorbent for removing sulfate from groundwater, providing a foundation for the application of scoria for groundwater environment restoration in cold regions in China. | Application and adsorption characteristics of scoria for removing sulfate from a low-temperature groundwater environment in Longdong area, China | 10.1007/s12665-021-10053-6 |
2021-10-25 | The study of slow earthquake activity, which occurs in the shallow and deep sides of seismogenic zone, is crucial for understanding subduction zones, including variations in frictional properties with depth and interplate coupling. Observations at the seafloor are necessary, particularly for shallow slow earthquakes occurring in offshore areas; however, few observations of such activity have been made. We conducted long-term seismic observations on the seafloor in the Hyuga-nada region, located at the western end of the Nankai Trough, to characterize shallow low-frequency tremor activity from 2014 to 2017. Although these observations lasted for only a few years, the occurrence frequency of shallow tremors in Hyuga-nada was lower than that of deep tremors in the Nankai Trough, and major activity involving migration occurred only once every two or more years. In contrast, minor activity with a duration of a few days occurred several times a year. Major activities in 2015 were accompanied by migration similar to those in 2013. The tremors in 2013 were characterized by south to north migration at a rate of 30–60 km/day. However, the tremors in 2015 were characterized by west to east migration, and the activity area extended further to the east. The migration rates were also much slower (several to 20 km/day) than in 2013. These different migration properties likely reflect the state of interplate coupling in the down-dip side of shallow slow earthquake area. Minor activity was identified, including tremors triggered by the 2015 Nepal and 2016 Kumamoto earthquakes. Activity occurred mainly in the focal regions of major activities. Very-low-frequency earthquakes (VLFEs) occurred concurrently with tremors, and their epicenters coincided within the margin of error. However, the VLFEs were mostly peripheral to the shallow tremor concentration zones. This indicates that minor heterogeneities in frictional properties are present along the shallow plate boundary. | Shallow tectonic tremor activities in Hyuga-nada, Nankai subduction zone, based on long-term broadband ocean bottom seismic observations | 10.1186/s40623-021-01533-x |
2021-10-25 | Background Sepsis is the leading cause of death worldwide in pediatric populations. Studies in low-resource settings showed that the majority of pediatric patients with sepsis still have a high mortality rate. Methods We retrospectively collected records from 2014 to 2019 of patients who had been diagnosed with sepsis and admitted to PICU in our tertiary hospital. Cox proportional hazard regression modeling was used to evaluate associations between patient characteristics and mortality. Results Overall, 665 patients were enrolled in this study, with 364 (54.7%) boys and 301 (46.3%) girls. As many as 385 patients (57.9%) died during the study period. The median age of patients admitted to PICU were 1.8 years old with interquartile range (IQR) ±8.36 years and the median length of stay was 144 h (1–1896 h). More than half 391 patients (58.8%) had a good nutritional status. Higher risk of mortality in PICU was associated fluid overload percentage of > 10% (HR 9.6, 95% CI: 7.4–12.6), the need of mechanical ventilation support (HR 2.7, 95% CI: 1.6–4.6), vasoactive drugs (HR 1.5, 95% CI: 1.2–2.0) and the presence of congenital anomaly (HR 1.4, 95% CI: 1.0–1.9). On the contrary, cerebral palsy (HR 0.3, 95% CI: 0.1–0.5) and post-operative patients (HR 0.4, 95% CI: 0.3–0.6) had lower mortality. Conclusion PICU mortality in pediatric patients with sepsis is associated with fluid overload percentage of > 10%, the need for mechanical ventilation support, the need of vasoactive drugs, and the presence of congenital anomaly. In septic patients in PICU, those with cerebral palsy and admitted for post-operative care had better survival. | Factors associated with mortality of pediatric sepsis patients at the pediatric intensive care unit in a low-resource setting | 10.1186/s12887-021-02945-0 |
2021-10-25 | In this study, descriptive statistics, correlation matrix, multiple regression model, and geostatistical models were used to assess the contamination of groundwater with respect to trace elements in the Lower Tano river basin, Ghana, West Africa. A total number of 48 boreholes drilled across the basin with depths ranging from 18 to 60 m were used as data sources in this study. The results of the descriptive statistics showed that the average lead, iron, and aluminium concentrations exceeded the WHO permissible limits of 0.3 mg/L, 0.01 mg/L, and 0.2 mg/L respectively. Furthermore, copper, chromium, aluminium, zinc, manganese, nickel, iron, arsenic, electrical conductivity, and total dissolved solids were found to be extreme and highly positively skewed. Even though significant correlations exist among some variables, the statistical results showed that the quality of the boreholes drilled across the basin was mainly originating from geogenic and anthropogenic sources. In addition, each pair of correlated physical parameters and trace elements in the drilled boreholes were predicted using multiple regression models. Likewise, geostatistical modelling was used to assess the spatial analysis of each pair of correlated physical parameters and trace elements in the drilled boreholes. The cross-validation results revealed kriging model, as the most precise model for the spatial distribution maps for the correlated physical parameters, and correlated trace elements concentration in the boreholes drilled across the study region. The semivariogram models showed that most of the correlated physical parameters and correlated trace elements were weak moderately and strongly spatially dependent, suggesting fewer agronomic influences. The results of the spatial analysis were consistent with the multiple regression model and the Pearson correlation matrix. | The use of statistical methods to assess groundwater contamination in the Lower Tano river basin, Ghana, West Africa | 10.1007/s10661-021-09514-z |
2021-10-22 | Background Skin-to-skin contact (SSC) practice improves newborn survival and child development through preventing hypothermia in newborns, improving early initiation of breastfeeding practice, and strengthening mother-child bonding. Despite having numerous benefits, it is one of the least practiced interventions in low and middle-income countries (1 to 74%). In Bangladesh, the prevalence of SSC was 26% in 2014. In this study, we aimed to estimate the prevalence of SSC in the study districts and identify factors that facilitate or inhibit SSC practice so that context-specific recommendations can be made to advance the use of this intervention. Methods We used baseline household survey data of USAID’s MaMoni MNCSP project conducted in 10 districts of Bangladesh in 2019. Our analysis included 13,695 recently delivered women (RDW) with a live birth outcome. Our primary outcome was the mother’s reported practice of SSC. We examined various antepartum, intrapartum, newborn, and sociodemographic factors associated with SSC using a multivariable generalized linear model. Our findings were reported using adjusted Prevalence Risk Ratios (aPRRs) and 95% Confidence Intervals (CIs). Results Overall, 28% of RDW reported practicing SSC across the 10 surveyed districts. Our multivariable analysis showed that public facility delivery (aPRR 2.01; 95%CI: 1.80, 2.26), private facility delivery (aPRR 1.23; 95%CI: 1.06, 1.42) and ≥ 4 antenatal care (ANC) visits at least one from a medically trained provider (MTP) (aPRR 1.17; 95%CI: 1.03, 1.26) had a significant positive association with SSC practice. Caesarean section (aPRR 0.64; 95%CI: 0.56, 0.73) had a significant negative association with SSC practice compared to vaginal births. We also found a significant positive association of SSC practice with mothers’ who perceived the birth size of their baby to be small, mothers with a higher education level (≥10 years), and mothers from households in the highest wealth quintile. Conclusions The prevalence of SSC is very low in the surveyed districts of Bangladesh. Considering the factors associated with SSC, relevant stakeholders need to increase their efforts on improving ANC and facility delivery coverages as well as improving SSC practice in the facilities especially after caesarean deliveries. Countries with a high burden of home deliveries, also need to emphasize community-based interventions and increasing coverage of skilled birth attendance for improving this life-saving intervention. | Prevalence and factors associated with skin-to-skin contact (SSC) practice: findings from a population-based cross-sectional survey in 10 selected districts of Bangladesh | 10.1186/s12884-021-04189-3 |
2021-10-22 | The order from quantum disorders (OFQD) phenomenon is well-known and ubiquitous in particle physics and frustrated magnetic systems. Typically, OFQD transfers a spurious Goldstone mode into a pseudo-Goldstone mode with a tiny gap. Here, we report an opposite phenomenon: OFQD transfers a spurious quadratic mode into a true linear Goldstone mode with a very small velocity (named slow-Goldstone mode). This new phenomenon is demonstrated in an interacting bosonic system subjected to an Abelian flux. We develop a new and systematic OFQD analysis to determine the true quantum ground state and the whole excitation spectrum. In the weak-coupling limit, the superfluid ground state has a 4-sublattice 90 ° coplanar spin structure, which supports 4 linear Goldstone modes with 3 different velocities. One of which is generated by the OFQD is much softer than the other 3 Goldstone modes, so it can be easily detected in the cold atom or photonic experiments. In the strong-coupling limit, the ferromagnetic Mott ground state with a true quadratic Goldstone mode. We speculate that there could be some topological phases intervening between the two symmetry broken states. These novel phenomena may be observed in the current cold-atom or photonic experiments subjected to an Abelian flux at the weak coupling limit where the heatings may be well under control. Possible connections to Coleman-Weinberg potential in particle physics, 1 /N expansion of Sachdev-Ye-Kitaev models and zero temperature quantum black hole entropy are outlined. | Slow-Goldstone mode generated by order from quantum disorder and its experimental detection | 10.1007/JHEP10(2021)190 |
2021-10-21 | Background Nitrogen (N) is an essential macronutrient that significantly affects turf quality. Commercial cultivars of bermudagrass ( Cynodon dactylon (L.) Pers.) require large amounts of nitrogenous fertilizer. Wild bermudagrass germplasm from natural habitats with poor nutrition and diverse N distributions is an important source for low-N-tolerant cultivated bermudagrass breeding. However, the mechanisms underlying the differences in N utilization among wild germplasm resources of bermudagrass are not clear. Results To clarify the low N tolerance mechanism in wild bermudagrass germplasm, the growth, physiology, metabolome and transcriptome of two wild accessions, C291 (low-N-tolerant) and C716 (low-N-sensitive), were investigated. The results showed that root growth was less inhibited in low-N-tolerant C291 than in low-N-sensitive C716 under low N conditions; the root dry weight, soluble protein content and free amino acid content of C291 did not differ from those of the control, while those of C716 were significantly decreased. Down-regulation of N acquisition, primary N assimilation and amino acid biosynthesis was less pronounced in C291 than in C716 under low N conditions; glycolysis and the tricarboxylic acid (TCA) cycle pathway were also down-regulated, accompanied by a decrease in the biosynthesis of amino acids; strikingly, processes such as translation, biosynthesis of the structural constituent of ribosome, and the expression of individual aminoacyl-tRNA synthetase genes, most of genes associated with ribosomes related to protein synthesis were all up-regulated in C291, but down-regulated in C716. Conclusions Overall, low-N-tolerant wild bermudagrass tolerated low N nutrition by reducing N primary assimilation and amino acid biosynthesis, while promoting the root protein synthesis process and thereby maintaining root N status and normal growth. | Integration of the metabolome and transcriptome reveals the mechanism of resistance to low nitrogen supply in wild bermudagrass (Cynodon dactylon (L.) Pers.) roots | 10.1186/s12870-021-03259-0 |
2021-10-21 | In this study, we have demonstrated the fabrication of perforated absorbers on two substrates, i.e., ITO/PET and Twill weave cloth. Perforation is required to enable the use of absorbers in the application where air breathability, ventilation and thermal equilibrium are necessary. For perforations, holes were machined in all the layers of the absorber. To ascertain the effect of perforations on both the absorbers’ performance, simulation, using ANSYS HFSS software, was carried out. In the ITO/PET-based absorber, it was found that there were no significant effects of the variation of hole radius on the absorption. However, for textile-based absorber, the hole radius had a significant impact on the absorption. The proposed ITO/PET-based fabricated MMA can absorb radiation in the frequency band from 7.64 GHz to 16.6 GHz, whereas the textile-based absorber can absorb more than 90% of the frequency band corresponding to 6.61 GHz to 17.91 GHz. The measured absorptions are found to be in good agreement with the simulated results. Furthermore, perforation gives two mechanical advantages to the absorber: first, it reduces the absorber’s weight by 25% and 35%, respectively, in the case of ITO/PET- and textile-based absorber, and second, it increases the bendability of the absorber. Through experiments, we found that the perforated sample bends by an extra 22 $$^{\circ }$$ ∘ and 24 $$^{\circ }$$ ∘ , respectively, for ITO/PET- and TWC-based absorber when placed as a cantilever. Theoretically, it was calculated that there would be a four-time increase in the absorber’s bendability due to perforations. | Perforated lightweight microwave metamaterial broadband absorber with discontinuous ground plane | 10.1007/s00339-021-05008-4 |
2021-10-19 | The present study demonstrates that the down-regulation of peroxisome proliferator-activated receptor-α (PPARα) results in chronic low ambient temperature (LT) exposure-induced cardiac dysfunction and remodeling, emphasizing the therapeutic potential of PPARα activation strategies (e.g. fenofibrate treatment) in LT-associated cardiac injury. | Targeting PPARα in low ambient temperature exposure-induced cardiac dysfunction and remodeling | 10.1186/s40779-021-00347-y |
2021-10-19 | Background The ability of 3D printing using plastics and resins that are magnetic resonance imaging (MRI) compatible provides opportunities to tailor design features to specific imaging needs. In this study an MRI compatible cradle was designed to fit the need for repeatable serial images of mice within a mouse specific low field MRI. Methods Several designs were reviewed which resulted in an open style stereotaxic cradle to fit within specific bore tolerances and allow maximum flexibility with interchangeable radiofrequency (RF) coils. CAD drawings were generated, cradle was printed and tested with phantom material and animals. Images were analyzed for quality and optimized using the new cradle. Testing with multiple phantoms was done to affirm that material choice did not create unwanted image artifact and to optimize imaging parameters. Once phantom testing was satisfied, mouse imaging began. Results The 3D printed cradle fit instrument tolerances, accommodated multiple coil configurations and physiological monitoring equipment, and allowed for improved image quality and reproducibility while also reducing overall imaging time and animal safety. Conclusions The generation of a 3D printed stereotaxic cradle was a low-cost option which functioned well for our laboratory. | Design and 3D-printing of MRI-compatible cradle for imaging mouse tumors | 10.1186/s41205-021-00124-6 |
2021-10-16 | Dopant-tunable transparent conductive oxide (≤ 50 nm) fabricated via electric-field-driven metal implantation (m-TCOs; m= Ni, Ag, and Cu) is demonstrated. The m-TCOs exhibit ultrahigh transparency, low sheet resistance, and broad work function tunability, leading to outstanding performance in various optoelectronic devices. The work function change is attributed to the interstitial metal atoms that provide the empty d-orbital, resulting in the shift of the Fermi level. Ultrathin film-based transparent conductive oxides (TCOs) with a broad work function (WF) tunability are highly demanded for efficient energy conversion devices. However, reducing the film thickness below 50 nm is limited due to rapidly increasing resistance; furthermore, introducing dopants into TCOs such as indium tin oxide (ITO) to reduce the resistance decreases the transparency due to a trade-off between the two quantities. Herein, we demonstrate dopant-tunable ultrathin (≤ 50 nm) TCOs fabricated via electric field-driven metal implantation ( m -TCOs; m = Ni, Ag, and Cu) without compromising their innate electrical and optical properties. The m -TCOs exhibit a broad WF variation (0.97 eV), high transmittance in the UV to visible range (89–93% at 365 nm), and low sheet resistance (30–60 Ω cm −2 ). Experimental and theoretical analyses show that interstitial metal atoms mainly affect the change in the WF without substantial losses in optical transparency. The m -ITOs are employed as anode or cathode electrodes for organic light-emitting diodes (LEDs), inorganic UV LEDs, and organic photovoltaics for their universal use, leading to outstanding performances, even without hole injection layer for OLED through the WF-tailored Ni -ITO. These results verify the proposed m -TCOs enable effective carrier transport and light extraction beyond the limits of traditional TCOs. | Dopant-Tunable Ultrathin Transparent Conductive Oxides for Efficient Energy Conversion Devices | 10.1007/s40820-021-00735-y |
2021-10-15 | Background Rose is one of most popular ornamental plants worldwide and is of high economic value and great cultural importance. However, cold damage restricts its planting application in cold areas. To elucidate the metabolic response of rose under low temperature stress, we conducted transcriptome and de novo analysis of Rosa xanthina f. spontanea . Results A total of 124,106 unigenes from 9 libraries were generated by de novo assembly, with N50 length was 1470 bp, under 4 °C and − 20 °C stress (23 °C was used as a control). Functional annotation and prediction analyses identified 55,084 unigenes, and 67.72% of these unigenes had significant similarity (BLAST, E ≤ 10 − 5 ) to those in the public databases. A total of 3031 genes were upregulated and 3891 were downregulated at 4 °C compared with 23 °C, and 867 genes were upregulated and 1763 were downregulated at − 20 °C compared with 23 °C. A total of 468 common DEGs were detected under cold stress, and the matched DEGs were involved in three functional categories: biological process (58.45%), cellular component (11.27%) and molecular function (30.28%). Based on KEGG functional annotations, four pathways were significantly enriched: metabolic pathway, response to plant pathogen interaction (32 genes); starch and sucrose metabolism (21 genes); circadian rhythm plant (8 genes); and photosynthesis antenna proteins (7 genes). Conclusions Our study is the first to report the response to cold stress at the transcriptome level in R. xanthina f. spontanea . The results can help to elucidate the molecular mechanism of cold resistance in rose and provide new insights and candidate genes for genetically enhancing cold stress tolerance. | Transcriptome and de novo analysis of Rosa xanthina f. spontanea in response to cold stress | 10.1186/s12870-021-03246-5 |
2021-10-15 | Background Animal communities are vulnerable to agricultural practices. Intensive farming considerably reduces overall arthropod diversity, but not necessarily pest abundance. Natural control of herbivores in agroecosystems is accomplished by predators and parasitoids, but in intensified agricultural regimes, the chemical control used to reduce pest abundances also affects pests’ natural enemies. To achieve more sustainable agriculture, there is a need to better understand the susceptibility of predators to conventional management. Methods In order to quantify the arthropod diversity associated with different schemes of agricultural management of maize, we evaluated agricultural fields under two contrasting management regimens in Michoacán, México during the spring–summer cycle of 2011. Arthropod communities were evaluated in plots with conventional high-input versus low-input agriculture in two sites—one rainfed and one with irrigation. The experimental units consisted of twelve 1 ha agricultural plots. To sample arthropods, we used 9 pitfall traps per agricultural plot. Results During the sampling period, we detected a total of 14,315 arthropods belonging to 12 Orders and 253 morphospecies. Arthropod community composition was significantly different between the sites, and in the rain-fed site, we also found differences between management practices. Predators, particularly ants, were more abundant in low-input sites. Herbivory levels were similar in all fields, with an average of 18% of leaf area lost per plant. Conclusions Our results suggest that conventional farming is not reducing herbivore abundances or damage inflicted to plants, but is affecting arthropod predators. We discuss repercussions for sustainable agriculture. | Comparison of arthropod communities between high and low input maize farms in Mexico | 10.1186/s43170-021-00060-9 |
2021-10-14 | According to the World Health Organization (WHO), air pollution is currently one leading cause of death around the world. As a result, some projects have emerged to monitor air quality through the implementation of low-cost Wireless Sensor Networks (WSNs). However, the type of technology and the sensors’ location have an impact on data quality, resulting in a considerable amount of missing data. This hinders the proper implementation of methodologies for sensor calibration and data leverage for dispersion analysis of pollutants and prediction of pollution episodes. This paper presents a methodology based on matrix factorization (MF) to recover missing data from a low-cost WSN for particulate matter PM2.5 measurement. Using the proposed methodology with the study case in Aburrá Valley, Colombia, it is shown that is possible to recover 40 % missing data with less than 12 % errors, obtaining better results than those presented by other methods found in the literature. | Missing Data Estimation in a Low-Cost Sensor Network for Measuring Air Quality: a Case Study in Aburrá Valley | 10.1007/s11270-021-05363-1 |
2021-10-11 | Although there has been a focus on THz filters so far, there is a significant deficiency in advancing low-temperature THz filters. According to the needs, we proposed a tunable THz filter that selectively permits the desired incident frequencies to be propagated in relevance with our purpose. The presence of a low-temperature nano superconductor and an undoped semiconductor layers in the proposed structure resulted in a multi-channel THz filter, which could be highly tuned with several parameters such as lattice constants, applied temperature, etc. The achieved transmittance spectra revealed that the emerged transmittance couples and stacks follow exact regulations. Furthermore, the structure exhibited omnidirectional band-gaps for both TE and TM polarized waves. Moreover, the use of a central defect layer gave some transmittance defect modes in the forbidden areas. This structure could be used in some THz devices such as switches, optimized sensors as well as in space industry and telecommunications. | Wave propagation in an optimized tunable multi-channel filter based on one-dimensional nano superconductor photonic crystal | 10.1007/s11082-021-03191-5 |
2021-10-11 | Atmospheric steam engines (ASE) were the first practical machines to convert thermal energy to mechanical work. However, their low efficiency and specific power relegated them to oblivion. Nevertheless, the recent urge for harnessing energy from heat sources with low to medium temperatures (100 to 150ºC), especially in renewable sources and waste heat, renewed the interest in this technology. However, since ASEs were constructed before the development of thermodynamics theories and concepts, there is a lack of studies on their operation cycle and optimization. Therefore, this work proposes a complete thermodynamical model for the adiabatic and isothermal atmospheric steam cycle that uses real gas data. The model is constructed to accommodate the forced expansion of the low-pressure steam. The results show that the adiabatic cycle is more efficient than the isothermal cycle and also that the amount of heat needed to keep the expanding steam at a constant temperature is prohibitive for practical applications. The data also indicate that with a moderate expansion ratio (r = 4) the adiabatic engine has a theoretical efficiency of 14%. The maximum efficiency obtained was 17,67% for r = 15. Furthermore, overheating presented a minor influence on the ASE theoretical efficiency. | Thermodynamical model of an atmospheric steam engine | 10.1007/s40430-021-03209-9 |
2021-10-11 | Using meteor radar, radiosonde observations and MERRA-2 reanalysis data from 12 August to 31 October 2006, we report a dynamical coupling from the tropical lower atmosphere to the mesosphere and lower thermosphere through a quasi-27-day intraseasonal oscillation (ISO). It is interesting that the quasi-27-day ISO is observed in the troposphere, stratopause and mesopause regions, exhibiting a three-layer structure. In the MLT, the amplitude in the zonal wind increases from about 4 ms −1 at 90 km to 15 ms −1 at 100 km, which is different from previous observations that ISOs occurs generally in winter with an amplitude peak at about 80–90 km, and then are rapidly weakened with increasing height. Outgoing longwave radiation (OLR) and specific humidity demonstrate that there is a quasi-27-day periodicity in convective activity in the tropics, which causes the ISO of the zonal wind and gravity wave (GW) activity in the troposphere. The upward propagating GWs are further modulated by the oscillation in the troposphere and upper stratosphere. As the GWs propagate to the MLT, the quasi-27-day oscillation in the wind field is induced with a clear phase opposite to that in the lower atmosphere through instability and dissipation of these modulated GWs. Wavelet analysis shows that the quasi-27-day variability in the MLT appears as a case event rather than a persistent phenomenon, and has not a clear corresponding relation with the solar rotation effect within 1 year of observations. | A quasi-27-day oscillation activity from the troposphere to the mesosphere and lower thermosphere at low latitudes | 10.1186/s40623-021-01521-1 |
2021-10-09 | Introduction Multi-parameter diagnostic devices can simplify cardiometabolic disease diagnosis. However, existing devices may not be suitable for use in low-resource settings, where the burden of non-communicable diseases is high. Here we describe the development of a target product profile (TPP) for a point-of-care multi-parameter device for detection of biomarkers for cardiovascular disease and metabolic disorders, including diabetes, in primary care settings in low- and middle-income countries (LMICs). Methods A draft TPP developed by an expert group was reviewed through an online survey and semi-structured expert interviews to identify device characteristics requiring refinement. The draft TPP included 41 characteristics with minimal and optimal requirements; characteristics with an agreement level for either requirement of ≤ 85% in either the survey or among interviewees were further discussed by the expert group and amended as appropriate. Results Twenty people responded to the online survey and 18 experts participated in the interviews. Twenty-two characteristics had an agreement level of ≤ 85% in either the online survey or interviews. The final TPP defines the device as intended to be used for basic diagnosis and management of cardiometabolic disorders (lipids, glucose, HbA1c, and creatinine) as minimal requirement, and offering an expanded test menu for wider cardiometabolic disease management as optimal requirement. To be suitable, the device should be intended for level 1 healthcare settings or lower, used by minimally trained healthcare workers and allow testing using self-contained cartridges or strips without the need for additional reagents. Throughput should be one sample at a time in a single or multi-analyte cartridge, or optimally enable testing of several samples and analytes in parallel with random access. Conclusion This TPP will inform developers of cardiometabolic multi-parameter devices for LMIC settings, and will support decision makers in the evaluation of existing and future devices. | Development of a target product profile for a point-of-care cardiometabolic device | 10.1186/s12872-021-02298-7 |
2021-10-08 | The ratio of hydrogen bonds in water molecules is significantly decreased by introducing oxygen-ligand Mg 2+ and hydrogen-ligand ClO 4 −, resulting in an ultralow solidifying point of − 121 °C. The excellent low-temperature physicochemical properties and good compatibility with Zn metal of 3.5 M (mol L −1 ) Mg(ClO 4 ) 2 + 1 M Zn(ClO 4 ) 2 electrolyte gives fabricated Zn||pyrene-4,5,9,10-tetraone (PTO) battery and Zn||Phenazine (PNZ) battery a satisfactory low temperature performance. Although aqueous zinc-ion batteries have gained great development due to their many merits, the frozen aqueous electrolyte hinders their practical application at low temperature conditions. Here, the synergistic effect of cation and anion to break the hydrogen-bonds network of original water molecules is demonstrated by multi-perspective characterization. Then, an aqueous-salt hydrates deep eutectic solvent of 3.5 M Mg(ClO 4 ) 2 + 1 M Zn(ClO 4 ) 2 is proposed and displays an ultralow freezing point of − 121 °C. A high ionic conductivity of 1.41 mS cm −1 and low viscosity of 22.9 mPa s at − 70 °C imply a fast ions transport behavior of this electrolyte. With the benefits of the low-temperature electrolyte, the fabricated Zn||Pyrene-4,5,9,10-tetraone (PTO) and Zn||Phenazine (PNZ) batteries exhibit satisfactory low-temperature performance. For example, Zn||PTO battery shows a high discharge capacity of 101.5 mAh g −1 at 0.5 C (200 mA g −1 ) and 71 mAh g −1 at 3 C (1.2 A g −1 ) when the temperature drops to − 70 °C. This work provides an unique view to design anti-freezing aqueous electrolyte. | Synergistic Effect of Cation and Anion for Low-Temperature Aqueous Zinc-Ion Battery | 10.1007/s40820-021-00733-0 |
2021-10-07 | Herein, novel isomeric diamines containing semi- N -methyl substituted bisbenzimidazole and derived polyimides (PIs) were successfully synthesized. Experimental data showed that the obtained PIs exhibited outstanding heat resistance and dimensional stability, including 5 % thermal weight loss temperature ( T d5 % ) of 547 ~ 557 °C, high glass transition temperature ( T g ) of 407 ~ 423 °C, and low coefficient of thermal expansion (CTE) of 2.2 ~ 17.6 ppm /°C. The influence of molecular structure of isomeric diamines, including para and ortho substituted N -methyl, on the molecular packing and properties of polymer was discussed. As a result, the novel PIs showed lower CTE than traditional PABZ (5-amino-2-(4-aminobenzene)-benzimidazole) based PIs without bringing high water absorption. These high-performance PI films with matching CTE of copper have potential applications in flexible display substrates and printed circuit boards. | Novel semi-N-methyl substituted bisbenzimidazole based polyimide films with low coefficient of thermal expansion and high Tg | 10.1007/s10965-021-02757-x |
2021-10-07 | Alzheimer’s disease (AD) is a chronic neurodegenerative disease characterized by the accumulation of amyloid β (Aβ) and neurofibrillary tangles. The last decade, it became increasingly clear that neuroinflammation plays a key role in both the initiation and progression of AD. Moreover, also the presence of peripheral inflammation has been extensively documented. However, it is still ambiguous whether this observed inflammation is cause or consequence of AD pathogenesis. Recently, this has been studied using amyloid precursor protein (APP) overexpression mouse models of AD. However, the findings might be confounded by APP-overexpression artifacts. Here, we investigated the effect of low-grade peripheral inflammation in the APP knock-in ( App NL-G-F ) mouse model. This revealed that low-grade peripheral inflammation affects (1) microglia characteristics, (2) blood-cerebrospinal fluid barrier integrity, (3) peripheral immune cell infiltration and (4) Aβ deposition in the brain. Next, we identified mechanisms that might cause this effect on AD pathology, more precisely Aβ efflux, persistent microglial activation and insufficient Aβ clearance, neuronal dysfunction and promotion of Aβ aggregation. Our results further strengthen the believe that even low-grade peripheral inflammation has detrimental effects on AD progression and may further reinforce the idea to modulate peripheral inflammation as a therapeutic strategy for AD. | Low-grade peripheral inflammation affects brain pathology in the AppNL-G-Fmouse model of Alzheimer’s disease | 10.1186/s40478-021-01253-z |
2021-10-06 | Background Glutenin contents and compositions are crucial factors influencing the end-use quality of wheat. Although the composition of glutenin fractions is well known, there has been relatively little research on the genetic basis of glutenin fractions in wheat. Results To elucidate the genetic basis for the contents of glutenin and its fractions, a population comprising 196 recombinant inbred lines (RILs) was constructed from two parents, Luozhen No.1 and Zhengyumai 9987, which differ regarding their total glutenin and its fraction contents (except for the By fraction). Forty-one additive Quantitative Trait Loci (QTL) were detected in four environments over two years. These QTL explained 1.3% - 53.4% of the phenotypic variation in the examined traits. Forty-three pairs of epistatic QTL (E-QTL) were detected in the RIL population across four environments. The QTL controlling the content of total glutenin and its seven fractions were detected in clusters. Seven clusters enriched with QTL for more than three traits were identified, including a QTL cluster 6AS-3 , which was revealed as a novel genetic locus for glutenin and related traits. Kompetitive Allele-Specific PCR (KASP) markers developed from the main QTL cluster 1DL-2 and the previously developed KASP marker for the QTL cluster 6AS-3 were validated as significantly associated with the target traits in the RIL population and in natural varieties. Conclusions This study identified novel genetic loci related to glutenin and its seven fractions. Additionally, the developed KASP markers may be useful for the marker-assisted selection of varieties with high glutenin fraction content and for identifying individuals in the early developmental stages without the need for phenotyping mature plants. On the basis of the results of this study and the KASP markers described herein, breeders will be able to efficiently select wheat lines with favorable glutenin properties and develop elite lines with high glutenin subunit contents. | Quantitative traits loci mapping and molecular marker development for total glutenin and glutenin fraction contents in wheat | 10.1186/s12870-021-03221-0 |
2021-10-05 | Background HIV stigma undermines a person’s wellbeing and quality of life and hinders HIV control efforts. This study examined the extent and drivers of HIV stigma in the teaching hospitals in Sana’a City, Yemen. The country has low HIV prevalence (4000 (2000-11,000) per 100,000) and limited HIV control funds, worsened by a long conflict and an economic crisis. Methods We conducted a cross-sectional study of 320 Yemeni health professionals in all the four teaching hospitals in Sana’a City. Data were collected anonymously, using an adapted self-completed Arabic version of the Health Policy Project HIV Stigma tool. The questionnaire covered the respondents’ background, the stigmatising practices, and potential personal and professional drivers of stigma. Results The majority of the participants were: females (68%), 20–39 years old (85%), nurses (84%), and holding a nursing diploma (69%) or a bachelor’s degree (27%). None of the hospitals had institutional policies against HIV stigma, and 93% of the participants believed the current infection control measures were inadequate. Less than half of the participants provided care for people living with HIV (PLHIV) (45%), had received HIV training (33%), and were confident that their HIV knowledge was adequate (23%). The majority indicated a preference to test patients for HIV prior to surgical procedures (77%) and disclose positive HIV results to others (99%) without prior knowledge or consent. All the participants had exhibited a form of HIV-related stigmatization, such as avoiding physical contact with PLHIV (87%) or wearing gloves throughout the consultation (96.5%). These practices were significantly correlated with the fear of infection, high perceived risk of infection, and poor work environment ( p < 0.05). Conclusion PLHIV face widespread stigmatizing behaviour in the teaching hospitals in Sana’a City, consistent with the higher level of stigma in low HIV prevalence countries and its links to the fear of infection, poor HIV knowledge, and limited funding for HIV control. Stigma reduction interventions are required at institutional and individual levels. In addition, anti-discrimination policies and structural adjustments are needed, in combination with training on HIV and universal precautions, and action to tackle negative attitudes towards PLHIV and key populations. | HIV stigma in the teaching hospitals in Sana’a, Yemen: a conflict and low-resource setting | 10.1186/s12889-021-11845-y |
2021-10-03 | Environmental monitoring requires periodic measurement of parameters such as pH, heavy metals, nitrates and phosphates in field settings, autonomously. Microfluidic devices have been considered for environmental sensing due to its inherent advantages of lower volume, faster sensing and low-cost fabrication. Various sensing methods including colorimetric, fluorescence and electrochemistry have been studied. Among them, colorimetric sensing is attractive due to its simple instrumentation and wide range of selective reagents. Nevertheless, it is limited by the use of liquid reagents which necessitates the use of energy-demanding valves and pumps that limit the lifetime of colorimetric systems in the field. Here, we demonstrate that threads can be used for solid state reagent storage in the dried form to facilitate autonomous measurement. When integrated together with a microfluidic device, the system was shown to control the volume of sample exposed to the stored reagent on a thread for a controlled sample-reagent interaction and demonstrated a measurable color change using a simple, low-cost system that minimizes energy cost by reducing the number of pumps and valves necessary. We develop a new approach to pattern and separate the dried reagents using paraffin wax to allow the thread to slide smoothly into the microfluidic device while preventing the sample from wetting the remaining thread allowing experiments to be performed at different timepoints. We demonstrate this platform for periodic measurement using pH and nitrites as examples of environmental monitoring which is extendable to other colorimetric analytes for periodic autonomous monitoring. We show that the device operates in a range of 1–5 mg/mL of nitrite and pH range of 6–7.4 which covers the regulatory range in many countries. | Patterned threads as solid-state reagent storage and delivery medium for automated periodic colorimetric monitoring of the environment | 10.1007/s10404-021-02496-x |
2021-10-01 | The article presents a new thermo-mechanical machining method for the manufacture of long low-rigidity shafts which combines straightening and heat treatment operations. A fixture for thermo-mechanical treatment of long low-rigidity shafts was designed and used in tests which involved axial straightening of shafts combined with a quenching operation (performed to increase the corrosion resistance of the steel used as stock material). The study showed that an analysis of the initial deflections of semi-finished shafts of different dimensions and determination of the maximum corrective deflection in the device could be used as a basis for performing axial straightening of shaft workpieces with simultaneous heat treatment and correction of the initial deflection of the workpiece. The deflection is corrected by stretching the fibers of the stock material, at any cross-section of the shaft, up to the yield point and generating residual stresses symmetrical to the axis of the workpiece. These processes allow to increase the accuracy and stability of the geometric shape of the shaft. | A thermo-mechanical machining method for improving the accuracy and stability of the geometric shape of long low-rigidity shafts | 10.1007/s10845-020-01733-4 |
2021-10-01 | Abstract As a promising photovoltaic technology, perovskite solar cells (pero-SCs) have developed rapidly over the past few years and the highest power conversion efficiency is beyond 25%. Nowadays, the planar structure is universally popular in pero-SCs due to the simple processing technology and low-temperature preparation. Electron transport layer (ETL) is verified to play a vital role in the device performance of planar pero-SCs. Particularly, the metal oxide (MO) ETL with low-cost, superb versatility, and excellent optoelectronic properties has been widely studied. This review mainly focuses on recent developments in the use of low-temperature-processed MO ETLs for planar pero-SCs. The optical and electronic properties of widely used MO materials of TiO 2 , ZnO, and SnO 2 , as well as the optimizations of these MO ETLs are briefly introduced. The commonly used methods for depositing MO ETLs are also discussed. Then, the applications of different MO ETLs on pero-SCs are reviewed. Finally, the challenge and future research of MO-based ETLs toward practical application of efficient planar pero-SCs are proposed. Graphical abstract | Low-temperature-processed metal oxide electron transport layers for efficient planar perovskite solar cells | 10.1007/s12598-020-01676-y |
2021-10-01 | Abstract The mechanical properties of the weld metal in a welded joint of low-carbon low-alloy 22K steel are studied using uniaxial tensile tests in the temperature range from room temperature to 1200°C. The changes in the structures and the strength and plastic properties of the base metal and the weld metal in the temperature range are compared and analyzed. | Effect of High Temperatures on the Mechanical Properties of the Weld Metal in the Welded Joint of Low-Carbon Low-Alloy Steel | 10.1134/S0036029521100256 |
2021-10-01 | The low-yielding-strength (LYS) steel is promising for energy-absorbing devices due to its outstanding plasticity. Although the mechanical properties of LYS steel for quasi-static and ultra-high-rate were studied, the link between them has not been established yet. Here we report both experiments and numerical simulations on the dynamic behavior of a LYS steel (quasi-static yielding stress > 225 MPa, LYS225) under moderate dynamic loadings, which covers the typical range of strain rate in engineering applications. Our results quantify the rate effect of LYS225 under moderate loading speed, and the strain-rate dependent constitutive and damage models are proposed. Moreover, the stress and strain concentration for elliptic-holed LYS225 plate is numerically analyzed based on the proposed constitutive model, which shows significant difference compared to the static solutions. This work could bridge the gap between their quasi-static and ultra-high-rate properties, thereby improve the designing precision of LYS steel-based energy-absorbing structures. | Strain-rate-dependent constitutive and damage models for a low-yielding-strength steel under dynamic loadings | 10.1007/s12206-021-0911-7 |
2021-10-01 | All-inorganic perovskite solar cells suffer from low performance due to unsatisfactory carrier transport and light harvesting efficiency. Semiconductor nanopillar arrays can reduce light reflection loss and suppress exciton recombination dynamics in optoelectronic devices. In all-inorganic perovskite solar cells, few studies employing TiO 2 nanopillar arrays (TiO 2 NaPAs) have been reported to improve the device performance. Herein, well-arranged TiO 2 NaPAs are chosen to enhance the interfacial contact between perovskite and electron transporting layers for improving the carrier transport. Notably, TiO 2 NaPAs can be directly fabricated on rigid/flexible substrates at roughly room temperature by unique glancing angle deposition, which is more available than high-temperature hydrothermal/solvothermal methods. By embedding TiO 2 NaPAs into chemical processable CsPbI 2 Br layers, continuous and intimate films are readily formed, guaranteeing large physical contact for facilitating more effective electron injection and charge separation. The vertically grown TiO 2 NaPAs also provide a straightforward electron transporting path to electrodes. In addition, TiO 2 NaPAs can guide the incident light and enhance the light-harvesting ability of CsPbI 2 Br films. As a result, the solar cell with TiO 2 NaPAs displays a power conversion efficiency of 11.35% higher than planar control of 10.04%, and exhibits better long-term thermal stability. This strategy provides an opportunity by constructing direct interfacial regulation towards the performance improvement of inorganic perovskite solar cells. | Interface engineering of high performance all-inorganic perovskite solar cells via low-temperature processed TiO2 nanopillar arrays | 10.1007/s12274-021-3566-x |
2021-10-01 | Background Xylanase, an important accessory enzyme that acts in synergy with cellulase, is widely used to degrade lignocellulosic biomass. Thermostable enzymes with good catalytic activity at lower temperatures have great potential for future applications in the feed and fuel industries, which have distinct demands; however, the potential of the enzymes is yet to be researched. Results In this study, a structure-based semi-rational design strategy was applied to enhance the low-temperature catalytic performance of Bispora sp. MEY-1 XYL10C_∆N wild-type (WT). Screening and comparisons were performed for the WT and mutant strains. Compared to the WT, the mutant M53S/F54L/N207G exhibited higher specific activity (2.9-fold; 2090 vs. 710 U/mg) and catalytic efficiency (2.8-fold; 1530 vs . 550 mL/s mg) at 40 °C, and also showed higher thermostability (the melting temperature and temperature of 50% activity loss after 30 min treatment increased by 7.7 °C and 3.5 °C, respectively). Compared with the cellulase-only treatment, combined treatment with M53S/F54L/N207G and cellulase increased the reducing sugar contents from corn stalk, wheat bran, and corn cob by 1.6-, 1.2-, and 1.4-folds, with 1.9, 1.2, and 1.6 as the highest degrees of synergy, respectively. Conclusions This study provides useful insights into the underlying mechanism and methods of xylanase modification for industrial utilization. We identified loop2 as a key functional area affecting the low-temperature catalytic efficiency of GH10 xylanase. The thermostable mutant M53S/F54L/N207G was selected for the highest low-temperature catalytic efficiency and reducing sugar yield in synergy with cellulase in the degradation of different types of lignocellulosic biomass. Graphic Abstract 1. Key sites were proved to promote low-temperature catalytic efficiency of xylanase. 2. Thermostable mutant with improved catalytic efficiency at 40 °C was obtained. 3. Synergistic hydrolysis was dramatically improved between the mutant and cellulase. 4. Agricultural wastes were converted into fermentable sugars by enzymolysis. | Improvement of XYL10C_∆N catalytic performance through loop engineering for lignocellulosic biomass utilization in feed and fuel industries | 10.1186/s13068-021-02044-3 |
2021-10-01 | In the drilling process of difficult-to-cut materials, conventional drilling has resulted in various problems such as high drilling temperature and poor machining quality. Low-frequency vibration-assisted drilling has great potential in overcoming these problems since broken chips are generated. In this paper, a low-frequency vibration-assisted drilling device is developed by using a novel ring flexure hinge as the elastic recovery mechanism. Firstly, based on the theory of elastic mechanics and mechanical vibration, the deflection of ring flexure hinge is designed theoretically, and the influence of its structural parameters on its deflection is analyzed. Then, the correctness of theoretical design is further verified by static and dynamic simulation and stiffness test. Finally, the vibration performance of the device is tested under no-load condition, and actual drilling test is conducted to verify the drilling performance. The results show that the device could realize the axial low-frequency vibration with constant frequency-to-rotation ratio and amplitude stepless adjustment and present good working stability under no-load and load conditions. In the actual drilling test of titanium alloy and carbon fiber–reinforced plastic (CFRP)/titanium alloy laminated structure, the device under appropriate processing parameters breaks titanium alloy chip into small pieces and reduces drilling temperature by 44% and inhibits secondary damage of CFRP. It provides the reference and guidance for the development of LFVAD device in presented work. | Development of a low-frequency vibration-assisted drilling device for difficult-to-cut materials | 10.1007/s00170-021-07668-1 |
2021-10-01 | The carbon vacancy in 4H-SiC is an important recombination center of the minority carrier and a direct consequence of SiC-based device degradation. In 4H-SiC, this defect acts as the primary carrier-lifetime killer. Whether, low-energy electron radiation exposure or high temperature processing in an inert ambient gas will produce the carbon vacancy defect. Despite, the extensiveness of the studies concerning the defect’s modeling and characterization, numerous essential questions remain. Amongst them, we have the impact of these defects on the performance of 4H-SiC MOSFET. Herein, the influence of intrinsic defect states, namely, Z 1/2 and EH 6/7 centers, on the 4H-SiC MOSFET electrical outputs is examined via 2D numerical simulation. The obtained results show that the traps act to increase the device on-state resistance ( R ON ), reduce the channel mobility, increase the threshold voltage ( V th ). Besides, the increase of the temperature leads to less influence of the traps on the threshold variation. Furthermore, due to their locations in the bandgap, the impact of both Z 1/2 and EH 6/7 centers at room temperature on the device electrical outputs is extreme. For high temperature the EH 6/7 have the severest impact because of the cross section temperature dependency. | Simulation Study of Carbon Vacancy Trapping Effect on Low Power 4H-SiC MOSFET Performance | 10.1007/s12633-020-00920-5 |
2021-10-01 | Based on the experimental data of full-range middle-low temperature coal tar (LTCT) hydrodeoxidation (HDO), the phenolic compounds (PC) in feedstock were divided into three lumps, four lumps or five lumps according to different reaction activities. Three corresponding lumping kinetic models of LTCT HDO were established. The Levenberg–Marguardt algorithm was used to calculate the kinetic parameters of each model. The fitting results of the three models are in good agreement with the experimental data, as the average relative error is less than 1.01%. Three types of lumped dynamic models are compared in detail, and the five-lumped model has an average relative error of less than 0.91%. Hence, this model can reliably predict PC removal and showed a good extrapolation performance. The effects of liquid hourly space velocity ( LHSV ), initial hydrogen pressure ( P ) and reaction temperature ( T ) on the HDO process of LTCT were analyzed by five-lumped model calculation, and the reaction law of HDO was obtained. The results show that the order of influence of various factors on the oxygen content of hydrogenated oil is LHSV > P ≥ T . Moreover, the hydrogenation process conditions were optimized by simulation: T = 663 K, P = 14 MPa, LHSV = 0.3 h −1 and V(H 2 )/V(Oil) of 1100:1, under which the expected oxygen content was 468.28 μg g −1 . The results of this study can also provide a scientific understanding of HDO mechanism, greatly reduce the number of LTCT industrial tests, reduce the oil inspection frequency, and help to improve the industrial hydrogenation process. | Lumped kinetic model for the hydrodeoxygenation of full-range middle-low temperature coal tar | 10.1007/s11144-021-02053-1 |
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