Abstract
Conservation agriculture (CA) practices are getting space world-wide to answer many emerging challenges like; declining factor productivity, deteriorating soil health, water scarcity, ...climate change, and farm profitability and sustainability. Oilseed brassica (Indian mustard,
Brassica juncea
L.), a winter oilseed grown under rainfed agro-ecosystem is vulnerable to low yields, high production cost, degrading soil and water quality, and climatic vagaries. The present study was undertaken on CA-based sustainable intensification of Indian mustard for enhancing inputs efficiencies, farm profitability and sustainability. Permanent beds with residue retention (PB + R) improved mustard equivalent yield (11.4%) and system grain yield (10.6%) compared with conventional tillage without residue (CT − R). Maize–mustard rotation (Mz–M) increased system grain yield (142.9%) as well as mustard equivalent yield (60.7%) compared with fallow-mustard (F-M). Mz–M system under PB + R increased sustainable yield index (376.5%), production efficiency (177.2%), economic efficiency (94%) and irrigation water productivity (66%) compared with F-M under CT − R. PB + R increased soil organic carbon (SOC) stock at 0–15 cm (17.7%) and 15–30 cm (29.5%) soil depth compared with CT − R. Addition of green gram in rotation with mustard improved SOC at 0–15 cm (27.4%) and 15–30 cm (20.5%) compared with F-M system. CA-based cluster bean-mustard/GG-M system increased N productivity, whereas, P and K productivity improved with Mz–M system compared with F-M under CT − R. Thus, CA-based Mz–M system should be out-scaled in the traditional rainfed fallow-mustard system to improve the farm production and income on holistic basis to make the country self-sufficient in edible oils.
Polyvinyl alcohol (PVA) is a synthetic, semi-crystalline, biodegradable and water soluble polymer having moderate mechanical properties. In the present investigation, restriction in water absorption ...of PVA is achieved by cross-linking with hydrochloric acid (HCl) which is confirmed by Fourier transform infrared spectroscopy (FTIR) and water uptake test. Results suggest that due to the formation of cross-linked bonds thermal and mechanical properties of PVA based cross-linked composite are improved as compared to pristine PVA. Further improvement in physical, mechanical and thermal properties is achieved by reinforcing basalt fibers. Tensile test results show that ultimate tensile strength (UTS) of basalt fiber reinforced composites increased by 79.4% as compared to the cross-linked PVA. Dynamic mechanical analysis of fabricated composites has been carried out to determine the storage modulus, glass transition temperature and activation energy. Effect of stress and temperature on creep and recovery behavior of cross-linked PVA and basalt fiber reinforced composite are studied and burger model is used to study the creep data.
The chemistry of organoselenium reagents provides an asset for organic synthesis. The versatility of these reagents as electrophiles and nucleophiles makes them one of the key components of organic ...synthesis. Various synthetic transformations such as oxyselenenylations, selenocyclization and selenoxide elimination have been successfully achieved using organoselenium reagents under mild reaction conditions. The presence of selenocysteine in a few mammalian enzymes was the key information for selenium chemists to explore the biochemistry of selenium compounds. Glutathione peroxidase (GPx), a mammalian selenoenzyme, is well known for maintaining redox equilibrium by detoxifying reactive oxygen species.
The aim is to critically analyze the recent development and prospects of synthesis and antioxidant properties of organoselenium compounds.
In this review, we summarised research and review papers from the PubMed and Scopus databases. The primary themes were linked to the synthesis of organoselenium compounds and their capacity to maintain cellular redox equilibrium when exposed to oxidative stress.
The study reveals that diselenide compounds synthesised by various methods showed a better antioxidant activity profile compared to selenides. In a few cases, the activity was found better than the standard compound ebselen. Moreover, the synthesis and antioxidant activity of Selenium-based nanoparticles have been also included.
In the past two decades, various biological properties of organoselenium compounds have been extensively studied, including the antioxidant properties. This review article will give insight into the synthesis of different types of recently synthesised organoselenium compounds. The review would be helpful to the researchers working in the field of medicinal chemistry in directing the synthesis of new organoselenium compounds as antioxidants.
The absence of a generic modeling framework in hydrology has long been recognized. With our current practice of developing more and more complex models for specific individual situations, there is an ...increasing emphasis and urgency on this issue. There have been some attempts to provide guidelines for a catchment classification framework, but research in this area is still in a state of infancy. To move forward on this classification framework, identification of an appropriate basis and development of a suitable methodology for its representation are vital. The present study argues that hydrologic system complexity is an appropriate basis for this classification framework and nonlinear dynamic concepts constitute a suitable methodology. The study employs a popular nonlinear dynamic method for identification of the level of complexity of streamflow and for its classification. The correlation dimension method, which has its base on data reconstruction and nearest neighbor concepts, is applied to monthly streamflow time series from a large network of 117 gaging stations across 11 states in the western United States (US). The dimensionality of the time series forms the basis for identification of system complexity and, accordingly, streamflows are classified into four major categories: low-dimensional, medium-dimensional, high-dimensional, and unidentifiable. The dimension estimates show some "homogeneity" in flow complexity within certain regions of the western US, but there are also strong exceptions.
•Ultrasonic shot peening (USSP) successfully developes nanostructure at the top surface of the alloy Ti-13Nb-13Zr.•Compressive residual stress at the top surface increases with duration of USSP ...treatment.•All the USSP treated samples showed improvement in corrosion resistance.•Titanium oxide was identified as main corrosion product.
The near-β Ti-13Nb-13Zr alloy was processed by ultrasonic shot peening (USSP) for different durations of 15–120 s to develop surface nanostructure. The effect of the USSP was studied on its corrosion behaviour in Ringer's solution, by electrochemical impedance spectroscopy and potentiodynamic polarization tests. The electrochemical study revealed reduction in corrosion of the USSP treated samples. There was maximum passivation in the 30 s of USSP treatment, while it decreased with an increase in USSP duration. The improvement in the corrosion resistance from USSP was due to grain refinement and the associated compressive residual stresses in the surface region.
The generally increasing volume of malware poses a challenge to the predominantly used static or dynamic analysis, which requires complex disassembly or time-intensive execution. Furthermore, high ...feature dimensionality and feature extraction costs per instance of malware increase overhead. The efficient classification of obfuscated malware, particularly for imbalanced classes, is a major challenge. This paper presents a visualization approach for malware classification to fill the gaps. Motivated by the visual similarity among malware from the same family, this paper proposes binary texture analysis over greyscale images created directly from their malware executables. The technique derives a novel combination of first-order and grey-level co-occurrence matrix (GLCM)-based second-order statistical texture features over the visualized malware. Using ensemble learning, the higher F1 score and accuracy obtained using Malimg (a benchmark Windows malware dataset) relative to those of state-of-the-art techniques and Windows executables first submitted to VirusTotal from 2018 to 2019 indicate higher efficiency and reliability of the proposed technique for malware classification. Additionally, the proposed technique is robust to obfuscation methods (e.g., packing, code relocation, and encryption). Indeed, the technique uses relatively fewer features extracted without disassembly or code execution in less time, thereby significantly enhancing the scalability of classifying a large-scale malware corpus.
The combination of low mass density, high frequency and high quality factor, Q, of mechanical resonators made of two-dimensional crystals such as graphene make them attractive for applications in ...force/mass sensing and exploring the quantum regime of mechanical motion. Microwave optomechanics with superconducting cavities offers exquisite position sensitivity and enables the preparation and detection of mechanical systems in the quantum ground state. Here, we demonstrate coupling between a multilayer graphene resonator with quality factors up to 220,000 and a high-Q superconducting cavity. Using thermomechanical noise as calibration, we achieve a displacement sensitivity of 17 fm Hz(-1/2). Optomechanical coupling is demonstrated by optomechanically induced reflection and absorption of microwave photons. We observe 17 dB of mechanical microwave amplification and signatures of strong optomechanical backaction. We quantitatively extract the cooperativity C, a characterization of coupling strength, from the measurement with no free parameters and find C = 8, which is promising for the quantum regime of graphene motion.
•Novel fin configuration inside PCM is investigated to reduce the peak temperature.•Heat load: 11 W; Operating Time: 10, 12 min out of 100 min cycle.•Heating time, % mass, number, shape & ...cross-section of fins are studied numerically.•Temperature drop of 29 K is achieved through novel star inverted frustum fin.
In the present study, the phase change material (PCM) based thermal control unit (TCU) has been analyzed to control the peak temperature (Tpk) of an electronic device. The pulsed heat load conditions are considered as an input to TCU. The PCM's low thermal conductivity is overcome by introducing the novel metallic fins, which are less complicated and easy to manufacture. Various parameters associated with the fin geometry are analyzed to identify fins' efficacy, namely, number of fins, % mass of fins, shape of fins, and cross-section of fins. Eight distinct fin configurations are studied viz. Prism – triangle and star; Frustum – triangle and star; Novel inverted frustum – circular, square, triangular, and star. The novel inverted fins have attained the highest area augmentation ratio with the lowest Tpk of 331.41 K at 25% mass of fins than other configurations. An overall reduction in Tpk is achieved around 9%, with novel inverted fins showing their significance inside PCM. The heating and cooling cycle ratio is 0.141, highest for the star inverted frustum at 25% mass of fin, suggesting that it can attain an initial temperature of 313 K way faster than other configurations.
The new capabilities of man-made micro/nanomotors open up considerable opportunities for diverse security and defense applications. This review highlights new micromotor-based strategies for enhanced ...security monitoring and detoxification of chemical and biological warfare agents (CBWA). The movement of receptor-functionalized nanomotors offers great potential for sensing and isolating target bio-threats from complex samples. New mobile reactive materials based on zeolite or activated carbon offer considerable promise for the accelerated removal of chemical warfare agents. A wide range of proof-of-concept motor-based approaches, including the detection and destruction of anthrax spores, 'on-off' nerve-agent detection or effective neutralization of chemical warfare agents have thus been demonstrated. The propulsion of micromotors and their corresponding bubble tails impart significant mixing that greatly accelerates such detoxification processes. These nanomotors will thus empower sensing and destruction where stirring large quantities of decontaminating reagents and controlled mechanical agitation are impossible or undesired. New technological breakthroughs and greater sophistication of micro/nanoscale machines will lead to rapid translation of the micromotor research activity into practical defense applications, addressing the escalating threat of CBWA.
It is hypothesized that groundwater major ions chemistry can be employed to determine the interaction between groundwater (GW) and saline water/seawater (SW) in costal aquifers, and that there exists ...a relationship between total dissolved solids with chloride, sodium, magnesium and sulphate concentrations of groundwater. This hypothesis was tested on a watershed located along the southeastern coast of India. From empirical data collected twice during pre- and post-monsoon seasons, it was found that in both seasons, out of 99.9% of the electrical conductivity (EC) variability due to the combined effect of Na
+, Ca
2+
+
Mg
2+,
SO
4
2
-
, Cl
−,
HCO
3
-
and
NO
3
-
, 54.0% was due to Cl
− alone in pre-monsoon, and 43.1% in post-monsoon. Results of factor analysis highlighted the multi-scale control of the fluid exchange and the influence of mixing zones between groundwater and saline water. Hydrochemical processes that accompany the intrusion of seawater were identified using ionic changes. It was observed during the sampling periods that the mixing due to seawater intrusion varied from 4.82% to 7.86% throughout the watershed. Negative values of ionic change (
e
change) for Na
+ and K
+ decreased with the increasing fraction of seawater.
PDF
