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• HYDRUS-1D can simulate couple of water and heat flow into straw-mulched soils. • Straw much layer (0–3 cm) consumed 0.57–1.20 mm water daily. • Straw mulching augments root-zone water content by reducing soil evaporation. • Straw mulch contributes vapor to total water flow. Numerical simulations for predicting soil-water and heat-flow regimes beneath mulched soils are important to increase the opportunity for efficient use of mulching in agriculture. This study simulated water and heat flows by HYDRUS-1D model under rice-straw mulching and bare soil treatments for rain-fed soybean (Glycine max) cultivation at Gifu Prefecture in central Japan. Soil hydraulic and thermal parameters with the straw mulching were optimized by adding a hypothetical 3-cm straw layer. The optimized parameters were validated with field-measured soil-moisture and temperature regimes of two consecutive soybean-growing seasons of 2015 and 2016. HYDRUS-1D model performed fairly well in simulating heat and water movements at 5, 15 and 25 cm soil depths under the two treatments. The model simulated soil moisture and temperature with small Root-Mean Square Error (RMSE): 0.016–0.044 cm3 cm–3 for soil moisture and 0.94–1.63 °C for soil temperature. The simulation results revealed that straw mulching increased soil moisture but reduced soil temperature at the three soil depths compared to the bare soil. The moisture content of the additional straw layer (3 cm) and heat flow through it showed a decreasing pattern compared to the soil layers. The straw mulching contributed 16–96% vapor to the total water flow and stored/released 0.0322 to 0.0295 MJ m–2 heat per day at 0–3 cm straw layer. Water balance in the soybean field revealed that the straw layer enhanced rain water infiltration by limiting evaporation from the soil surface. The simulation results can be useful for better management of soil hydro-thermal regimes under straw-mulched fields in dryland cultivations. [ABSTRACT FROM AUTHOR]

Drivers of nitrogen (N) mineralization in paddy soils, especially under anaerobic soil conditions, are elusive. The influences of exogenous organic matter (OM) and fertilizer application on the activities of five relevant enzymes (β-glucosaminidase, β-glucosidase, l -glutaminase, urease and arylamidase) were measured in two long-term field experiments. Of the two field experiments, the 18-year field experiment was established in a weathered terrace soil with rice-wheat crop rotation at the Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU) farm with five OM treatments and two levels of mineral N fertilizer. The 30-year experiment was established in a young floodplain soil with rice-rice crop rotation at the Bangladesh Agricultural University (BAU) farm with five mineral fertilizer treatments including one with farm yard manure. At BSMRAU, N fertilizer and OM amendments significantly increased all enzyme activities, suggesting the availability of primarily substrate for microbial activity. Whereas at BAU, non-responsiveness of β-glucosidase activity, suggesting that fertilizer and OM amendments had little effect on overall soil microbial activity. Nevertheless the microbial demand for N, β-glucosaminidase and l -glutaminase activities differed among the treatments (P < 0.05) and showed opposite trends with soil N mineralization. Hence enzymatic pathways to acquire N differed with the treatment at BAU site, indicates differences in soil N quality and bio-availability. l -glutaminase activity was the sole investigated variable that positively correlated to both the aerobic and anaerobic N mineralization rates in both field experiments. Combined with a negative correlation between β-glucosaminidase activity and N mineralization rate, it appears that terminal amino acid NH 2 hydrolysis was a rate-limiting step for soil N mineralization at the BAU site. Future investigations with joint quantification of polyphenol accumulation and binding of N alongside an array of extracellular enzymes, including oxidases for phenols and hydrolases for N-compounds, would enable verification of the hypothesized binding and stabilization of N with accumulating polyphenols at BAU site under SOM storing management. [ABSTRACT FROM AUTHOR]

The global temperature has been increasing over the years due to climate change that, directly or indirectly, affects water and energy consumptions in the agriculture sector. The application of mulching practices reduces soil evaporation, conserves soil moisture, suppresses weed growth, controls soil structure and temperature, influences soil micro-organisms, and is aesthetically pleasing. This study has reviewed 189 published research papers, which described the effects of various mulching materials and methods on soil and environment that influence crop productivity. This paper describes the extent of influence of different mulching materials and methods on the hydrothermal environment of soils. It is imperative to know the processes that control soil environments under various mulching conditions and the effects of mulching materials on crop yield, productivity and water use efficiency. These issues of mulching are the prime concerns of this review study. Plastic mulching materials have a greater importance than the organic ones to control soil environment and increase crop yield. But, the organic mulching materials are inexpensive and environment friendly. The selection of an appropriate mulching material is, however, guided by crop type, crop management practices and climatic conditions. Future research is needed on the effects of low-cost biodegradable mulching materials on microclimate modifications, soil biota, soil fertility, crop growth and crop yields. [ABSTRACT FROM AUTHOR]

The pore collapse mechanisms of closed-cell aluminium foams during quasi-static compression have been investigated. A suite of experiments and numerical simulations were carried out to elucidate the deformation pathways of individual pores during quasi-static compressive loading. X-ray computed tomography was utilized to generate 3D views of the foams before and after deformation. The tomography based foam geometry was imported into the finite element software ABAQUS/Explicit for simulations. The results showed that the simulations accurately reproduced the experimentally observed yielding and post yielding behaviour of the foams. As expected, pores with thin cell-walls were observed to deform at faster rates both experimentally and in simulations. The simulations aided to reveal the complex deformation evolution of cell-walls and junctions (plateau borders) during compression. While the cell-walls experienced bending, buckling and rotation by forming hinges; the plateau borders experienced considerably less deformation. The thickness/strength of cell-walls and topological foams' heterogeneities are observed as the governing factors for collapse. Significant lateral strain is observed at the cell level, although the bulk lateral strain was negligible. Finally, it was also observed that the micro-pores and cracks present within the cell-walls contribute to their deformation. [ABSTRACT FROM AUTHOR]

Plate-impact experiments have been conducted to investigate the elastic–plastic behaviour of shock wave propagation and pore collapse mechanisms of closed-cell aluminium foams. FE modelling using a meso-scale approach has been carried out with the FE software ABAQUS/Explicit. A micro-computed tomography-based foam geometry has been developed and microstructural changes with time have been investigated to explore the effects of wave propagation. Special attention has been given to the pore collapse mechanism. The effect of velocity variations on deformation has been elucidated with three different impact conditions using the plate-impact method. Free surface velocity ( u fs ) was measured on the rear of the sample to understand the evolution of the compaction. At low impact velocities, the free-surface velocity increased gradually, whereas an abrupt rise of free-surface velocity was found at an impact velocity of 845 m/s with a copper flyer-plate which correlates with the appearance of shock. A good correlation was found between experimental results and FE predictions. [ABSTRACT FROM AUTHOR]

Conservation Agriculture (CA) is still a relatively new approach for intensively cultivated (3 crops yr-1) rice-based cropping systems that produce high crop yield and amounts of residues annually. With the recent development of transplanting of rice into tilled strips on non-puddled soil, CA could become feasible for rice-based cropping patterns. However, the effect of increased retention of crop residues on crop response to nitrogen (N) fertilization rate in strip tilled systems with the transplanted rice and other crops grown in the annual rotation is yet to be determined. For nine years, we have examined the effects of soil disturbance levels - strip tillage (ST) and conventional tillage (CT), two residue retention levels –15% residue by height (low residue, LR) and 30% residue (high residue, HR) and five N rates (60%, 80%, 100%, 120%, and 140% of the recommended N fertilizer doses (RFD)) for a rice-wheat-mungbean cropping sequence. The 100% RFD was 75, 100 and 20 kg N ha-1for rice, wheat, and mungbean, respectively. Rice yields were comparable between the two tillage systems for up to year-6, wheat for up to year-3 but mungbean yield markedly increased in ST from year-1; however, the land equivalent ratio increased from year-1, principally because of higher mungbean yield. Introduction of ST increased land equivalent ratio by 26% relative to CT, N use efficiency and partial factor productivity. Nitrogen fertilizer demand for maximum yield in ST was increased by about 10% for rice and 5% for mungbean but decreased by 5% for wheat. Although fertilizer N demand had increased in ST system due to higher yield than CT, the N requirement declined by50–90% when the same yield goal is considered for ST as for CT. The soil organic carbon stock (0–15 cm) after 8 years increased from 21.5 to 30.5 t ha-1 due to the effect of ST plus high crop residue retention. Annual gross margin increased by 57% in ST over CT practice and 26% in HR over LR retention. In conclusion, after 9 years practicing CA with increased residue retention under strip tillage, the crops had higher N use efficiency, grain yield, land equivalent ratio and annual gross margin in the rice-wheat-mungbean cropping system while the N fertilizer requirement increased minimally. • Strip tillage (ST) with residue retention increased crop profitability. • Adoption of ST practice increased N use efficiency. • The ST practice required about 10% more N but produced higher rice crop yield. • Strip tillage plus residue retention increased SOC stock by 9 t ha-1 over 8 years. [ABSTRACT FROM AUTHOR]

This study investigates the influence of microstructure on the strength properties of individual cell walls of closed-cell stabilized aluminium foams (SAFs). Optical microscopy (OM), micro-computed X-ray tomography (µ-CT), electron backscattering diffraction (EBSD), and energy dispersive X-ray spectroscopy (EDS) analyses were conducted to examine the microstructural properties of SAF cell walls. Novel micro-tensile tests were performed to investigate the strength properties of individual cell walls. Microstructural analysis of the SAF cell walls revealed that the material consists of eutectic Al-Si and dendritic a-Al with an inhomogeneous distribution of intermetallic particles and micro-pores (void defects). These microstructural features affected the micro-mechanism fracture behaviour and tensile strength of the specimens. Laser-based extensometer and digital image correlation (DIC) analyses were employed to observe the strain fields of individual tensile specimens. The tensile failure mode of these materials has been evaluated using microstructural analysis of post-mortem specimens, revealing a brittle cleavage fracture of the cell wall materials. The micro-porosities and intermetallic particles reduced the strength under tensile loading, limiting the elongation to fracture on average to ~3.2% and an average ultimate tensile strength to ~192 MPa. Finally, interactions between crack propagation and obstructing intermetallic compounds during the tensile deformation have been elucidated. [ABSTRACT FROM AUTHOR]

Highlights: [•] This paper highlights the conversion of tamarind seed into bio-oil by pyrolysis. [•] Crushed seed was pyrolized in an internally heated fixed bed fire tube reactor. [•] The maximum liquid yield was 45wt% at 400°C for a feed size of 3200μm. [•] Suitability of the liquid product obtained from tamarind seed as an alternative fuel. [ABSTRACT FROM AUTHOR]

Abstract: An advanced technique of morphology observation of conducting filler-reinforced nitrile rubber composites by electrostatic force microscopy is reported. The composites were prepared by mixing carbon blacks and multi-walled carbon nanotubes with nitrile rubber. Increase in the voltage applied to the probe tip in electrostatic force microscopy enhanced clear visibility of carbon black particles and their distribution in the rubber matrix. The surface topography of the composite indicated the presence of carbon black aggregates having different size and structure depending on the type of carbon black. The electrostatic force microscopy images of carbon nanotube-filled composite clearly showed the presence of bundles of nanotubes embedded in the rubber matrix. The average diameter of nanotube bundles was found to be around 50nm. [Copyright &y& Elsevier]

Sorghum ( Sorghum bicolor L. Moench) seeds were examined to determine the influence of exposure to ascending and descending imbibition temperature regimes on plumule and radicle axes behaviour of seed after treatment. Treatments included soaking in distilled water, 4.5 % NaCl or 4.5 % KCl for 3 days at three ascending or descending temperatures ranging from 11 to 21 °C. Root growth was enhanced by descending temperatures (21, 16 and 11 °C) over the 3-day period, whereas ascending temperatures (11, 16 and 21 °C) increased growth differences between shoots and roots. Shoot–root growth was affected by imbibition temperature to a greater extent than germination. However, seed soaking treatments in NaCl or KCl did not improve root or shoot growth, but did improve germination rates. [ABSTRACT FROM AUTHOR]

Strain rate sensitivity and deformation mechanisms of closed-cell aluminium foams under low-velocity impact loadings are investigated in this study. Instrumented drop-weight impact experiments and Finite Element (FE) modelling were conducted to explore the deformation rate dependency of aluminium foams (manufactured by CYMATTM corporation). An X-ray micro-Computed Tomography (XCT) reconstructed foam geometry was used in the FE modelling approach to explore actual deformation mechanisms and strain rate sensitivity of foams. The deformation and pore collapse mechanisms were explored through investigating the stress and plastic strain contours. Our results show that the FE modelling with rate-dependent material properties agreed with the dynamic experimental results. The foam showed significant rate sensitivity within the examined range of strain rates. Our modelling and experimental results collectively indicate that the rate sensitivity of the base material is the primarily responsible for enhancing strength during impacts. Furthermore, the FE modelling with rate-independent material properties and unique foam topology confirms the negligible inertia effect at low velocity impacts. [ABSTRACT FROM AUTHOR]

The low-velocity impact response of closed-cell aluminium foams using various shaped indenters has been investigated. Impact tests were conducted using an instrumented drop-tower with flat, hemispherical, conical and truncated-conical indenter at impact energies ranging from 46.8 J to 105 J. The effects of variation of indenter shape and impact velocity on mechanical properties and deformation mechanisms of foam have been explicitly investigated. The results show that the mechanical response of closed-cell aluminium foams under low-velocity projectile impact significantly depends on the indenters' nose shape and initial impact energy. The deformation mechanisms of foam for different shaped indenters have been elucidated using reconstructed X-ray micro-computed tomography (XCT) images of the indented specimens. A good correlation between the indenter shape and deformation mechanisms has been observed. The structure-property relations of foams during dynamic indentation have also been explored by analysing the XCT images of the indented specimens. The parameters that influence the energy absorption capacity of the material are also presented. Unlabelled Image • Dynamic indentation response of closed-cell aluminium foam depends on indenter's nose shape. • Specific energy absorption increases with the increase of impact velocity. • Nose shape of impactor influences the deformation behaviour and energy absorption in closed-cell foams. • Deformation in dynamic indentation initiates just underneath the indenter and propagates with the indenter's movement. [ABSTRACT FROM AUTHOR]

• Progression of structural deformation reduces structural heterogeneity. • Impact induces localised densification triggered by the collapse of large voids. • Band-wise deformation impedes sharp increase in stress and delays the densification. • Impact deformation clusters pores with spatial similar orientation. • Pores form increasing topological correlation during impact events. The mechanical properties of closed-cell aluminium foams are governed by their geometrical and topological evolution during impact. Here we non-destructively investigate the deformation mechanisms of a closed-cell aluminium foam sample at the cell scale. The sample has been compressed with 21 interrupted drop-weight impacts at a nominal strain rate of 40 s−1 and the post-impacted sample has been imaged at four pertinent strain states with high-resolution X-ray micro-computed tomography (XCT). Moreover, a number of qualitative and quantitative structural analyses are carried out using advanced 3D image analyses to understand the effect of foam geometry/topology on its mechanical response. Our results show that the deforming microstructure creates strong correlations across a range of geometrical, topological and shape characteristics. Quantitative image analyses of the sample at four different strain states reveal that the regions with large void fractions predominantly undergo collapse and subsequently reduces the structural heterogeneity. Further, we show that the deformation mechanism leaves topological signatures in the evolving microstructure, which can be used to better understand the mechanical response of the sample at various stages of impact-deformation. We demonstrate here, for the first time, how the topological quantities can be used to explore the foam deformation mechanisms and to correlate the deformation with mechanical response during impact. Image, graphical abstract [ABSTRACT FROM AUTHOR]

• Straw and newspaper mulching reduce soil-water consumption for soybean cultivation. • Organic mulches enhance up to 37% soybean yield compared to no mulching. • Newspaper mulching reduces temperature of 0–30 cm soil rooting zones. • Newspaper could be an alternative option to straw mulching. Soybean (Glycine max) is a commercially important oilseed crop across the world; it is also popularly used as vegetables, cookery and fodder crops in Japan. In areas with limited rainfall and high temperature, mulching can provide greater yield of rain-fed soybean by improving soil hydro-thermal regimes. However, organic mulching like rice straw and shaded newspaper being inexpensive, rapidly degradable, easy to use, and environment friendly may provide more benefits than plastic mulching. Field experiments with rain-fed soybean cultivation were done in 2015 and 2016 at Gifu University farm in Japan. The purposes were to investigate the effects of rice straw and newspaper mulching on moisture and temperature regimes of soil, soil-water consumption (SWC), soil-moisture extraction pattern (SMEP), total readily available moisture (TRAM), water use efficiency (WUE) as well as growth and yield of soybean. Mulching increased seasonal soil-moisture content with lesser fluctuations in the root zone compared to bare soil, and lowered soil temperature by 2 °C at 5 cm and 0.5–1.0 °C at 15–25 cm soil depths. Straw mulch reduced SWC by 41.8 and 13.9% in 2015 and 2016, respectively compared to bare soil; the corresponding reduction in SWC under newspaper mulch was 16.6 and 20.6%. Consequently, mulching improved WUE by 25–47% compared to bare soil. Mulching significantly (p ≤ 0.05) improved plant height, leaf chlorophyll content, nodulations, grain (pod) and seed numbers, biomass, and grain and seed yields of soybean compared to bare soil. Grain yield increased by 12–13% under straw mulching and 6.6–37.2% under newspaper mulching compared to bare soil. Newspaper mulch provided higher yield and WUE by maintaining lower soil temperature and SWC , and greater soil moisture compared to straw mulch. Thus, newspaper can be an alternative option to rice straw mulch for improving soil hydro-thermal regimes for rain-fed soybean cultivation. [ABSTRACT FROM AUTHOR]

[Display omitted] • A high yield vacuum-type pyramid-solar-still was investigated experimentally. • Hourly and daily productivity enhanced by 22.3 % and 63 % respectively. • Distillation and exergy efficiencies were improved by 28.7 % and 22.4 % respectively. • Incorporation of PCM with vacuum condition outperformed conventional solar stills. In this study, a solar-energy-driven high performance water purification system is designed, fabricated, and examined, which may be useful for remote areas with limited access to grid electricity and underground freshwater. This research aims to enhance the performance of a conventional solar still (double-slope type) by creating vacuum inside the chamber and using paraffin wax (PCM) as energy storage material. The performance of the modified solar still (SS) is investigated and compared with the conventional solar still (CSS) in terms of productivity, distillation efficiency, and exergy efficiency. The performance analyses show that the hourly productivity and daily cumulative productivity are increased by 22.33 % and 63 % (from 5.46 L/m2 to 7.03 L/m2) respectively for the modified still compared to the conventional still. Nearly 28.72 % distillation efficiency and 22.43 % exergy efficiency enhancement are recorded for the modified system compared to the conventional system. This study also reveals that the thermal performance of the modified system is significantly improved under vacuum condition and using paraffin wax as heat storage material, which enables the still to operate at low solar intensities. The economic analysis shows that the cost of freshwater produced per liter in the modified SS is 41.4 % less than that of the conventional SS. [ABSTRACT FROM AUTHOR]

Background Alzheimer's disease ( AD) is a progressive neurodegenerative disorder clinically characterized by loss of memory and cognition. The effective therapeutic options for AD are limited and thus there is a demand for new drugs. Aegle marmelos ( Linn.) ( A. marmelos) leaves have been used in traditional medicine to promote intellect and enhance memory. In this study, we evaluated A. marmelos for its acetylcholinesterase ( AChE) inhibitory activity and antioxidant property in vitro in the treatment of AD. Methods A crude methanol extract and four fractions (petroleum ether, chloroform, ethyl acetate and aqueous) were prepared from the leaves of A. marmelos. The preparations were assessed for AChE inhibitory activity by the Ellman method, and their antioxidant properties were assessed by several assays: reducing power, scavenging of 1,1-diphenyl-2-picrylhydrazyl free radical and hydroxyl radical, and inhibition of lipid peroxidation. Qualitative and quantitative analyses of endogenous substances in A. marmelos were performed by the standard phytochemical methods. Results Among the different extracts tested, the ethyl acetate fraction exhibited the highest inhibition of AChE activity. In the same way, ethyl acetate fraction showed the highest reducing activity and radical scavenging ability towards the 1,1-diphenyl-2-picrylhydrazyl (half maximal inhibitory concentration = 3.84 μg/mL) and hydroxyl free radicals (half maximal inhibitory concentration = 5.68 μg/mL). The antiradical activity of the ethyl acetate fraction appeared to be similar to that of the reference standard butylated hydroxytoluene and catechin used in this study. In addition, the ethyl acetate fraction displayed higher inhibition of brain lipid peroxidation. Phytochemical screening of different extractives of A. marmelos showed the presence of phenols and flavonoids, alkaloid, saponin, glycoside, tannin and steroids. Quantitative analysis revealed higher contents of phenolics (58.79-mg gallic acid equivalent/g dried extract) and flavonoids (375.73-mg gallic acid equivalent/g dried extract) in the ethyl acetate fraction. Conclusion The results suggest that the ethyl acetate fraction of A. marmelos is a significant source of polyphenolic compounds with potential AChE inhibitory property and antioxidant activity and, thus, may be useful in the treatment of AD. [ABSTRACT FROM AUTHOR]

Abstract: Polymer films of sago starch/polyvinyl alcohol (PVA) were prepared by casting and cured under ultra violet (UV) radiation. Different blends were made varying the concentration of sago starch and PVA. Tensile strength (TS) and elongation at break (Eb) of the prepared films were studied. Films made up of sago starch and PVA with a ratio of 1:2 showed the highest TS and Eb. The physico-mechanical properties of prepared films were improved by grafting with acrylic monomers with the aid of UV radiation. A series of formulations was prepared with two monomers 2-ethyl 2-hydroxymethyl 1,3 methacrylate (EHMPTMA) and 2-ethylhexylacrylate (EHA) and a photoinitiator. Monomer concentration, soaking time and radiation dose were optimized in terms of grafting and mechanical properties. The highest TS was at 50% EHMPTMA and 48% EHA and 2% photo initiator at 5min soaking time and recorded value was 6.58MPa. The prepared films were further characterized with NMR spectroscopy and scanning electron microscope (SEM). [Copyright &y& Elsevier]

The adoption of conservation agriculture (CA) in the intensive triple-cropping, rice-based systems of the Eastern Gangetic Plain (EGP) alters the dynamics of carbon (C) in the soil, but the nature of these changes is poorly understood. Our aim was to determine whether CA in these systems involving non-puddled transplanting of wetland rice and strip planting of dryland crops plus increased residue retention would increase the C storage in soils relative to conventional crop establishment practices. Long-term field experiments were studied in two locations of northwestern Bangladesh to determine C turnover as well as examining C cycling under three levels of soil disturbance (conventional tillage (CT), strip planting (SP) and bed planting (BP)) in combination with low residue (straw) retention (LR, the current practice) and increased residue retention (HR) in Calcareous Brown Floodplain soil (Alipur) and Grey Terrace soil (Digram). The total nitrogen (N), organic C, microbial biomass C (MBC) and water-soluble C (WSC) values were measured in soil samples from 0 to 10 cm depth collected at different stages during the growth of the 13th and 14th crops at Alipur and the 12th and 13th crops at Digram since the treatments commenced. At each location, SP and BP with either LR or HR retained more soil organic C (0–10 cm) from C inputs than CT with HR and LR. In general, the CO 2 emissions relative to the stored soil organic C in the soils (0–10 cm) under SP with LR and HR were approximately 13 to 59% lower than those under CT and BP with LR and HR. The higher levels of C mineralization were associated with higher WSC contents in the soil. In contrast, the MBC contents in the HR treatments followed the order SPHR > BPHR > CTHR. Similarly, in SPLR and SPHR, the potentially mineralizable C (PMC) was higher, while the decay rate constant was lower. Increased residue retention with minimal soil disturbance practices (SP and non-puddled transplanting) after 14 crops at Alipur and 13 crops at Digram modified the C cycle by decreasing C emissions and increasing the levels of total organic C in the soil. The application of both minimal soil disturbance and increased residue retention enhanced soil organic C (0–10 cm) concentrations in the two soils under intensive rice-based cropping systems on the EGP. [ABSTRACT FROM AUTHOR]

An increase in the storage of carbon (C) in soil by changing management practices can help to mitigate climate change and increase soil quality. The objective of this study was to evaluate the best management options for reducing greenhouse gas (GHG) emissions. An ecosystem model DayCent was tested for two rice (Oryza sativa L. ) experimental sites in Bangladesh. The sites are under different management practices and we first tested the models ability to simulate SOC turnover, and then estimated the potential for SOC sequestration by comparing change in SOC for each management scenario with baseline management (current farmers’ practices) including conventional tillage, 5% residue incorporation and nitrogen (N) fertilizer. Predicted yield was also compared at both sites to ensure that yield was not compromised by mitigation measures. A control treatment was tested at both sites. At site 1, two other treatments of mineral N fertilizer, and combination of farmyard manure (FYM) and N were tested in a double rice based crop rotation. At site 2, a treatment receiving cowdung (CD) application, and a combination of CD and N were tested in a wheat ( Triticum aestivum L.)-rice based crop rotation. The DayCent model was able to simulate SOC increase from the double rice test sites under unfertilized conditions, considering additional N and C sources in the simulations. Assuming N fertilizer (180 kg N ha −1 yr −1 ) application for site 1, and CD application (25 t ha −1 yr −1 ) for site 2, respectively, as the baseline, four single, and one integrated, scenarios were implemented in the model to predict SOC and yield at both sites. Two additional scenarios with alternate wet and drying (AWD) as a single treatment, and as part of an integrated approach, were also tested for their mitigation potential at site 1. The highest simulated positive impact on SOC development (60% higher than that of the baseline) was observed at site 1 when FYM was used in place of mineral N fertilizer. As there is a yield penalty associated with the use of only FYM, integrated approaches might show more promise, such as inclusion of 15% residue return, reduced tillage, less mineral N fertilizer, FYM addition, with or without AWD. This approach increases SOC by up to 23% while keeping the yield stable (nearly 3.5 t ha −1 ). The application of CD only as determined for baseline of site 2, gives a yield of about 1.8 t ha −1 yr −1 . In contrast nearly two times more yield was obtained under the scenario associated with integrated management which also increases SOC by 30% relative to the baseline at the second site. Net GHG emissions, including nitrous oxide and methane emissions were estimated using the Intergovernmental Panel on Climate Change (IPCC) tier 1 methods, and country specific emission factors (where available), suggests that the integrated management scenario can reduce the net GHG emissions from 0.58-0.82 t carbon dioxide (CO 2 )-eq. ha −1 yr −1 (equivalent to 0.16-0.24 t Ceq. ha −1 yr −1 ) at site 2, while a net reduction in GHGs of nearly 1.00 t CO 2 -eq. ha −1 yr −1 (equivalent to 0.27 t Ceq. ha −1 yr −1 ) at site 1 was only achieved if AWD was also implemented with the integrated management scenario. Future studies could attempt to model non-CO 2 GHGs with a dynamic model. [ABSTRACT FROM AUTHOR]

The dynamic compressive response of closed-cell (CYMAT™) stabilised aluminium alloy foams (SAF) has been investigated using a modified Split Hopkinson Pressure Bar (SHPB) in conjunction with a high-speed camera. Tests have been carried out on 45 mm diameter and 23 mm thick cylindrical specimens. The elastic-plastic pore collapse mechanism has been investigated using Digital Image Correlation (DIC) and micro-computed X-ray tomography. A stress-strain relationship for individual specimens at different impact velocities has been obtained with the combination of an analytical method and SHPB theory. The large deformation (∼80%) has been measured from eight strain gauges’ data using a wave separation algorithm. The test results exhibited a significant increase in elastic and plastic strength during the pulse loading. The X-ray tomography data of pre-impacted and post-impacted SAF specimens have been extensively analysed to elucidate the internal elastic-plastic pore collapse mechanisms. [ABSTRACT FROM AUTHOR]

Emissions from flares constitute unburned hydrocarbons, carbon monoxide (CO), soot, and other partially burned and altered hydrocarbons along with carbon dioxide (CO2) and water. Soot or visible smoke is of particular concern for flare operators/regulatory agencies. The goal of the study is to develop a computational fluid dynamics (CFD) model capable of predicting flare combustion efficiency (CE) and soot emission. Since detailed combustion mechanisms are too complicated for (CFD) application, a 50-species reduced mechanism, LU 3.0.1, was developed. LU 3.0.1 is capable of handling C4hydrocarbons and soot precursor species (C2H2, C2H4, C6H6). The new reduced mechanism LU 3.0.1 was first validated against experimental performance indicators: laminar flame speed, adiabatic flame temperature, and ignition delay. Further, CFD simulations using LU 3.0.1 were run to predict soot emission and CE of air-assisted flare tests conducted in 2010 in Tulsa, Oklahoma, using ANSYS Fluent software. Results of non-premixed probability density function (PDF) model and eddy dissipation concept (EDC) model are discussed. It is also noteworthy that when used in conjunction with the EDC turbulence-chemistry model, LU 3.0.1 can reasonably predict volatile organic compound (VOC) emissions as well. Implications: A reduced combustion mechanism containing 50 C1–C4species and soot precursors has been developed and validated against experimental data. The combustion mechanism is then employed in the computational fluid dynamics (CFD) of modeling of soot emission and combustion efficiency (CE) of controlled flares for which experimental soot and CE data are available. The validated CFD modeling tools are useful for oil, gas, and chemical industries to comply with U.S. Environmental Protection Agency’s (EPA) mandate to achieve smokeless flaring with a high CE. [ABSTRACT FROM AUTHOR]

A pre-stressing technique for improving the ballistic performance of a circular silicon carbide tile has been tested against ø12-mm spherical steel projectile. The confining pre-stress was achieved through a heat-shrunk steel collar and was evaluated through neutron diffraction for the ceramic-collar system. Subsequent ballistic experiments and simulations of the impact event were used to elucidate the mechanisms and benefits of pre-stress on the ballistic response. CT-scans of various specimens, post-impact, show that the pre-stress affects the trajectory of the Hertzian cone and limits the overall damage. Furthermore, simulations qualitatively agreed with the experimental result, showing a reduction in crack propagation and altered paths of damage. Greater confining stress led to higher negative triaxiality, which act to arrest the tensile hoop stresses and corresponding cracks. • Measured strain in pre-stressed SiC tiles using neutron diffraction. • Pre-stress alters Hertzian cone morphology during ballistic loading. • Cover plate behaviour a metric for ballistic performance. • Computational model informs fracture response. Image, graphical abstract [ABSTRACT FROM AUTHOR]