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Chemical activation is known to induce specific surface features of porosity and functionality which play a definite role in enhancing the adsorptive potential of the developed ...activated carbons. Different conditions of temperature, time, reagent type and impregnation ratio were applied on sawdust precursor and their effect on the physical, surface chemical features and finally on the adsorption potential of the developed activated carbons were analysed. Under activation conditions of 600°C, 1hr, 1:0.5 ratio, ZnCl2 impregnated carbon (CASD_ZnCl2) resulted in microporosity while KOH impregnation (CASD_KOH) yielded a carbon having a wider pore size distribution. The surface chemistry revealed similar functionalities. At same pH, temperature and adsorbate concentrations, CASD_KOH demonstrated better adsorption potential (1.06mmoles/g for Cd2+ and 1.61mmoles/g for Ni2+) in comparison to CASD_ZnCl2 (0.23mmoles/g and 0.33mmoles/g for Cd2+ and Ni2+ respectively). Other features were a short equilibrium time of 60mins and an adsorbent dose of 0.2g/L for the CASD_KOH in comparison to CASD_ZnCl2 (equilibrium time of 150min and dosage of 0.5g/L). The nature of interactions was physical for both adsorbents and pore diffusion mechanisms were operative. The results reveal the potentiality of chemical activation so as to achieve the best physico-chemical properties suited for energy efficient, economical and eco-friendly water treatment.
Summary
Escherichia coli biofilm consists of a bacterial colony embedded in a matrix of extracellular polymeric substances (EPS) which protects the microbes from adverse environmental conditions and ...results in infection. Besides being the major causative agent for recurrent urinary tract infections, E. coli biofilm is also responsible for indwelling medical device‐related infectivity. The cell‐to‐cell communication within the biofilm occurs due to quorum sensors that can modulate the key biochemical players enabling the bacteria to proliferate and intensify the resultant infections. The diversity in structural components of biofilm gets compounded due to the development of antibiotic resistance, hampering its eradication. Conventionally used antimicrobial agents have a restricted range of cellular targets and limited efficacy on biofilms. This emphasizes the need to explore the alternate therapeuticals like anti‐adhesion compounds, phytochemicals, nanomaterials for effective drug delivery to restrict the growth of biofilm. The current review focuses on various aspects of E. coli biofilm development and the possible therapeutic approaches for prevention and treatment of biofilm‐related infections.
Enzymatic treatment for juice extraction is most commonly used now a days. The enzymatic process is claimed to offer a number of advantages over mechanical-thermal comminution of several fruit pulps. ...Enzymes are an integral component of modern fruit juice manufacturing and are highly suitable for optimizing processes. Their main purposes are: increase extraction of juice from raw material, increase processing efficiency (pressing, solid settling or removal), and generate a final product that is clear and visually attractive. Juice extraction can be done by using various mechanical processes, which may be achieved through diffusion extraction, decanter centrifuge, screw type juice extractor, fruit pulper and by different types of presses. Enzymatic treatment prior to mechanical extraction significantly improves juice recovery compared to any other extraction process. Enzymatic hydrolysis of the cell walls increases the extraction yield, reducing sugars, soluble dry matter content and galacturonic acid content and titrable acidity of the products. Enzymatic degradation of the biomaterial depends upon the type of enzyme, incubation time, incubation temperature, enzyme concentration, agitation, pH and use of different enzyme combinations. We can conclude from the technical literature that use of the enzymes i.e. cellulases, pectinases, amylases and combination of these enzymes can give better juice yield with superior quality of the fruit juice. Pectinase enzyme can give maximum juice yield i.e. 92.4% at 360 minutes incubation time, 37°C incubation temperature and 5 mg/100 g of enzyme concentration. Whereas the combination of two enzymes i.e. pectin methyl esterase (PME) and polygalacturonase (PG) at 120 minutes of incubation time, 50°C of incubation temperature and 0.05 mg/100 gm of enzymatic concentration can give the maximum yield of 96.8% for plum fruits. This paper discusses the use of enzymes in fruit juice production focusing on the juice recovery, clarity and effect of the particular enzyme on the biochemical properties of the fruit juices.
•Isolation of Bacillus aryabhattai-related bacterial isolates with zinc-solubilizing abilities.•Bacterial isolates produced organic acids and solubilized insoluble zinc compounds.•Rhizosphere ...inoculation of two crops mobilized native soil zinc from unavailable forms.•Improved growth, yield and zinc content in soybean and wheat crops upon inoculation.•First report of B. aryabhattai-related isolates from rhizosphere of soybean cultivated in India.
Zinc deficiency not only affects crop yields, but also nutritional quality and human health. Microbial transformation of unavailable forms of soil zinc to plant available zinc is an important approach contributing to plant zinc nutrition and growth promotion. Therefore, the objectives were to (a) assess in vitro zinc solubilization ability of Bacillus aryabhattai strains MDSR7, MDSR11 and MDSR14 in medium supplemented with three insoluble zinc salts (zinc oxide, zinc carbonate and zinc phosphate) and (b) to evaluate their response of inoculation on crop growth, soil biological properties, zinc mobilization from native zinc-pool of soil and acquisition by soybean and wheat under microcosm conditions. The microcosm experiment comprised of five treatments for each crop, viz., (1) un-inoculated control without crop (non-rhizosphere soil); (2) un-inoculated control with crop; (3) B. aryabhattai MDSR7; (4) B. aryabhattai MDSR11; and (5) B. aryabhattai MDSR14 in completely randomized block design with twelve replications. While testing under in vitro, all the three strains possessed IAA, siderophore and ammonia producing traits. The strains MDSR7 and MDSR14 produced substantially higher soluble zinc content with significant decline in pH and increase in total organic acid production in Tris-minimal broth supplemented with insoluble zinc compounds. Further on inoculation with MDSR7 and MDSR14 substantially decreased rhizosphere soil pH and increased dehydrogenase, β-glucosidase, auxin production, microbial respiration and microbial biomass-C in the rhizosphere soils of soybean and wheat. The operation of all these soil processes regulated by B. aryabhattai strains resulted in a depletion of organically complexed and calcium carbonate bound zinc and an increase in exchangeable and sesquioxide bound zinc in soil. Such enhanced microbial activities and redistribution among different zinc pools in rhizosphere might have paved way for increased plant available zinc resulting in increased growth promotion and zinc assimilation in seeds by soybean and wheat crops. This assumes significance as the increased zinc concentration found in this study has large implications in terms of overcoming zinc malnutrition. We conclude that the strains MDSR7 and MDSR14 substantially influenced mobilization of zinc and its concentration in edible portion, yield of soybean and wheat, and can be utilized as bio-inoculants for biofertilization and biofortification.
Molecular markers, due to their stability, cost-effectiveness and ease of use provide an immensely popular tool for a variety of applications including genome mapping, gene tagging, genetic diversity ...diversity, phylogenetic analysis and forensic investigations. In the last three decades, a number of molecular marker techniques have been developed and exploited worldwide in different systems. However, only a handful of these techniques, namely RFLPs, RAPDs, AFLPs, ISSRs, SSRs and SNPs have received global acceptance. A recent revolution in DNA sequencing techniques has taken the discovery and application of molecular markers to high-throughput and ultrahigh-throughput levels. Although, the choice of marker will obviously depend on the targeted use, microsatellites, SNPs and genotyping by sequencing (GBS) largely fulfill most of the user requirements. Further, modern transcriptomic and functional markers will lead the ventures onto high-density genetic map construction, identification of QTLs, breeding and conservation strategies in times to come in combination with other high throughput techniques. This review presents an overview of different marker technologies and their variants with a comparative account of their characteristic features and applications.
Toxicity of textile wastewaters (untreated and treated) and their ingredient chemicals was quantified in terms of their chemical characteristics, fish (
Gambusia affinis) mortality and end point ...growth responses of duckweed (
Lemna aequinoctialis) in short-term bioassays. Other parameters of fish bioassay were erythrocyte morphology and its counts. Despite of a definite correlation between data of biological tests (LC/EC
50 values) with that of chemical tests, biological tests were found to be relatively more sensitive to both wastewaters and ingredient chemicals. Amongst all the examined parameters of test organisms, fish RBCs (morphology and counts) sensitivity to pollutants in the wastewaters was usually maximum and therefore, their study should be included in the routine fish bioassay. Other advantage of biological test such as on
Lemna is even detection of eutrophic potential of wastewaters, as noted at their higher dilutions. The ingredient chemicals (major) contributing maximum toxicity to textile dye wastewater were, acids (HCl and H
2SO
4), alkali (Na
2O SiO
2), salt (NaNO
2) and heavy metal (Cu), whereas dyes (4) were relatively less toxic.
Multiwavelength data indicate that the X-ray-emitting plasma in the cores of galaxy clusters is not cooling catastrophically. To a large extent, cooling is offset by heating due to active galactic ...nuclei (AGNs) via jets. The cool-core clusters, with cooler/denser plasmas, show multiphase gas and signs of some cooling in their cores. These observations suggest that the cool core is locally thermally unstable while maintaining global thermal equilibrium. Using high-resolution, three-dimensional simulations we study the formation of multiphase gas in cluster cores heated by collimated bipolar AGN jets. Our key conclusion is that spatially extended multiphase filaments form only when the instantaneous ratio of the thermal instability and free-fall timescales (t sub(TI)/t sub(ff)) falls below a critical threshold of approx =10. When this happens, dense cold gas decouples from the hot intracluster medium (ICM) phase and generates inhomogeneous and spatially extended H alpha filaments. These cold gas clumps and filaments "rain" down onto the central regions of the core, forming a cold rotating torus and in part feeding the supermassive black hole. Consequently, the self-regulated feedback enhances AGN heating and the core returns to a higher entropy level with t sub(TI)/t sub(ff) > 10. Eventually, the core reaches quasi-stable global thermal equilibrium, and cold filaments condense out of the hot ICM whenever t sub(TI)/t sub(ff) < ~ 10. This occurs despite the fact that the energy from AGN jets is supplied to the core in a highly anisotropic fashion. The effective spatial redistribution of heat is enabled in part by the turbulent motions in the wake of freely falling cold filaments. Increased AGN activity can locally reverse the cold gas flow, launching cold filamentary gas away from the cluster center. Our criterion for the condensation of spatially extended cold gas is in agreement with observations and previous idealized simulations.
•Higher system productivity and efficiency possible through conservation agriculture.•Zero-till cereal system had superior performance than the conventional-till.•Maize is a potential substitute of ...rice in areas with shortages of labor and water.•Avoiding puddling and residue retention in rice saves 30% water with no yield loss.•Conservation agriculture had cumulative and likely long-term benefits.
Increasing scarcity of resources (labour, water, and energy) and cost of production, along with climate variability, are major challenges for the sustainability of rice–wheat system in the northwesten Indo-Gangetic Plains (IGP). We hypothesized that adopting the principles of conservation agriculture together with best crop management practices would improve system productivity and overall efficiency, resulting in a higher profitability. To test this hypothesis, we evaluated the performance of four cropping system scenarios (treatments), which were designed to be adapted to current and future drivers of agricultural changes. The treatments including farmers practices varied in tillage and crop establishment methods, residue management, crop sequence, and crop management. Zero-tillage direct-seeded rice (ZT-DSR) with residue retention and best management practices provided equivalent or higher yield and 30–50% lower irrigation water use than those of farmer-managed puddled transplanted rice (CT-TPR). Overall, net economic returns increased up to 79% with a net reduction in production cost of up to US$ 55ha−1 in ZT-DSR than CT-TPR. Substituting rice with ZT maize was equally profitable but with 88–95% less irrigation water use. Avoiding puddling in rice and dry tillage in maize with residue retention increased yield (by 0.5–1.2tha−1) and net economic returns of the succeeding wheat crop. Inclusion of mungbean in the rotation further increased system productivity and economic returns. In summary, our initial results of 2-year field study showed positive effects of CA-based improved management practices on yield and system efficiencies with greater benefits in the second year. There is a need of longer term monitoring to quantify cumulative effects of various interventions and to eventually make recommendations for wider dissemination.
The interfacial strength, vibrations attenuation and delamination resistance of carbon fiber reinforced polymer composites (CFRPCs) can be significantly improved by introducing different nano-species ...(nanotube/nanorods/nanowalls/nanowires) on the carbon fiber (CF) surface. A review on the performance of carbon nanotubes (CNTs), zinc oxide (ZnO) nanowalls, nanowires, and other nano-species, modified CFRPCs is presented. The approaches to optimize the size and maximize the density of nanotubes and nanorods on the CF surface based on the available literature data are discussed. It could be concluded based on the discussion that the dense-thin-long-fibers produce better mechanical performance and in addition to improving interfacial strength, nanotubes/rods share the load with fibers and improve the toughness of CFRPC. The finite element (FE) model is constituted for observing the stresses at CNT, CF, and interface of CF/CNT during tensile loading. A FE model analyzing variation in mechanical properties of CF due to possible defects is reviewed. The analysis of data revealed under-utilization of the strength of CNTs in CFRPC. Later, a discussion on the fractography of CFRPCs with nano-species/other treatments along with some original FE results required for discussion is presented. This review should provide a faster and better understanding of the research area addressed.
An advanced mode of drug delivery system has been developed to overcome the major drawbacks associated with conventional drug delivery systems. This review gives a detailed idea about a nanoemulsion ...system. Nanoemulsions are nano-sized emulsions, which are manufactured for improving the delivery of active pharmaceutical ingredients. These are the thermodynamically stable isotropic system in which two immiscible liquids are mixed to form a single phase by means of an emulsifying agent, i.e., surfactant and co-surfactant. The droplet size of nanoemulsion falls typically in the range 20–200 nm. The main difference between emulsion and nanoemulsion lies in the size and shape of particles dispersed in the continuous phase. In this review, the attention is focused to give a basic idea about its formulation, method of preparation, characterization techniques, evaluation parameters, and various applications of nanoemulsion.