Special Diffraction Effects in Al7o_xCo15Cux+yNi15_y Decagonal Alloys

Stable decagonal phases are observed to form in both as cast and rapid solidification condition in Al70Co15Nil5 and A16SCo20Cu15 alloys. The former shows diffraction spots and diffuse intensity at positions other than those of a decagonal phase in the 10-fold and 2-fold diffraction patterns. These compounds are stabilised at a specific e/a ratio. Therefore, quaternary alloys with general alloy composition A17o-,Co15Cux,,,Nils-,, were prepared with varying e/a ratio. We present here the electron metallographic characterisation of the melt-spun ribbons of different alloy compositions. Changes observed during electron microscopic investigation include streaking and diffuse intensity around the spots and also the presence of totally diffuse rows in some cases. The consequence of the latter on the underlying structure is disorder in the decagonal phase. Owing to the presence of streaking in a 10-fold like zone in the A170Co15Cu5Nilo composition, symmetry breaking of 10-fold to a 2-fold Diagonal phase (222) occurs. Further, the presence of a type II superstructure is also observed in A168Co 15Cu 17Ni5 composition

Utilization of wetland ecosystem through fish-crop diversification for enhanced productivity and economic stability for fish-farm community of Indian sub-continent

This paper deals with a number of case studies that were undertaken during the last 8- 10 years in utilizing divergent æTalÆ wetland ecosystems (deep, semi-deep, temporary in a range of agro-ecological zones like NAZ, OAZ and Coastal Zone of the region) for the development of integrated management programmes using a range of approaches. These included (i) system approach (excavation & renovation, methodological approach), (ii) management (fish-crop management, inter & post-harvest care & processing, marketing), (iii) integrated natural resource management utilizing organic as well inorganic sources, and (iv) low-cost fish-feeds, based on fish-crop diversification. This paper also deals with some endangered indigenous fish species. The unique approach of watershed plans (bherri system), which were formulated for upright production systems, was economically successful. Economic indicators reveal there were comparative advantages of mixed farming systems compared to monoculture, exhibiting less than 2.5 fold gains even for resource poor fish farming families.Fishery management, Resource management

Biomimetic synthesis of hybrid nanocomposite scaffolds by freeze-thawing and freeze-drying

The aim of this study is to biomimetically synthesize hydroxyapatite - hydrophilic polymer scaffolds for biomedical applications. This organic-inorganic hybrid has been structurally characterized and reveals a good microstructural control as seen by the SEM analysis and the nanosize of the particulates is confirmed by AFM microscopy. The characterization of such nano-structured composites would allow researchers to design new systems, tailoring properties for different applications. © Indian Academy of Sciences

Boiling Study of Nanofluid on Graphene Coated Substrate

A comparative study is done to understand the effect of variation in surface energy of substrates on boiling and dry-out characteristics of nanofluid. Droplet of TiO2 nanofluid on glass substrate shows strong pinning along the droplet perimeter. As the droplet evaporates, boundary of nanofluid droplet recedes slowly towards the center leaving a ring-shaped stain of concentrated nanoparticles. Surface energy of glass substrate is modified by graphene coating, confirmed by increase in contact angle. While boiling of nanofluid on graphene coated glass substrate shows an almost uniform dry-out pattern. Reduced wettability of nanofluid droplet on graphene coated glass substrate is responsible for this behavior

Growth of carbon nanotubes on quasicrystalline alloys

We report on the synthesis of carbon nanotubes on quasicrystalline alloys. Aligned multiwalled carbon nanotubes (MWNTs) on the conducting faces of decagonal quasicrystals were synthesized using floating catalyst chemical vapor deposition. The alignment of the nanotubes was found perpendicular to the decagonal faces of the quasicrystals. A comparison between the growth and tube quality has also been made between tubes grown on various quasicrystalline and SiO2 substrates. While a significant MWNT growth was observed on decagonal quasicrystalline substrate, there was no significant growth observed on icosahedral quasicrystalline substrate. Raman spectroscopy and high resolution transmission electron microscopy (HRTEM) results show high crystalline nature of the nanotubes. Presence of continuous iron filled core in the nanotubes grown on these substrates was also observed, which is typically not seen in MWNTs grown using similar process on silicon and/or silicon dioxide substrates. The study has important implications for understanding the growth mechanism of MWNTs on conducting substrates which have potential applications as heat sinks

Point defect induced incommensurate dipole moments in the KCa2Nb3O10 Dion-Jacobson layered perovskite

Local structural distortions due to isolated atomic defects and defect complexes strongly affect the macroscopic properties of oxide ceramics. While the characterization of local defect structures is more common in simple ABO3 perovskites, unambiguous determination of the same in layered perovskites is more difficult due to their complex crystal structures. Here, we combined x-ray pair distribution function and density functional theory calculations to characterize the structure of cation-oxygen divacancy pairs in a Dion-Jacobson (D-J) layered perovskite. Our results indicate that local incommensurate dipole moments with polarization density in the range of ∼0.1–17μC/cm2 are created due to divacancy-induced structural distortions in the D-J phase KCa2Nb3O10. This is comparable with defect dipole moments observed in well-known perovskite ferroelectrics. The current results imply that controlling the atomic defects can potentially lead to significant control of dielectric properties in D-J layered perovskites

Productivity, water use efficiency and soil properties of sugarcane as influenced by trash mulching and irrigation regimes under different planting systems in sandy loam soils

IntroductionIn the era of climate change, sugarcane used to face a problem associated with water shortage due to erratic rainfall patterns and lowered water tables. Improved water use efficiency using innovative crop management strategy is needed for sustainable sugarcane production. Trash mulching with different irrigation regimes can effectively modify the plant's hydrothermal micro-environment for increasing cane yield and water productivity.MethodsKeeping this in the background, a field experiment was conducted at Sugarcane Research Institute, RPCAU, Pusa, India, from 2016–17 to 2018–19 to investigate the effects of trash mulching and irrigation regimes on sugarcane productivity, water use efficiency (WUE) and soil properties in different planting systems. The field experiment comprised 12 treatments including four planting methods viz. conventional flat planting (CF; 75 cm row spacing) with trash mulching (6 t ha−1), CF planting (75 cm row spacing) without trash mulching (6 t ha−1), paired row trench (PT) planting (30: 120 cm row spacing) with trash mulching (6 t ha−1), PT planting (30: 120 cm row spacing) without trash mulching (6 t ha−1) and three irrigation schedules consisted of irrigation water (IW); cumulative pan evaporation (CPE) ratio of 0.60, 0.80, and 1.00 was laid out in strip plot design with three replications.Results and discussionThe cane yield (103.5 t ha−1) was found significantly higher in PT planting with trash mulching over the CF planting method with or without mulching. Concerning irrigation regimes using the IW/CPE ratio, it was found that the IW/CPE of 0.6 resulted in 16.9, 13.3% higher water-use efficiency, and 37.1, 40.7% higher water productivity over those under IW/CPE of 0.8, and 1.00, respectively. Furthermore, soil parameters like soil microbial biomass carbon (SMBC) and dehydrogenase activity were increased by 12.5, and 17.5 % due to trash mulching with trench planting as compared to those under conventional flat planting without mulching. The results suggest that planting sugarcane in paired rows and irrigation scheduling at 1.00 IW/CPE with the adoption of trash mulching practices is effective for increasing profitability by way of higher sugarcane productivity and water productivity and also in sustaining soil health

Cytotoxic Withanolide Constituents of Physalis longifolia

Fourteen new withanolides, 1–14, named withalongolides A–N, respectively, were isolated from the aerial parts of Physalis longifolia together with eight known compounds (15–22). The structures of compounds 1–14 were elucidated through spectroscopic techniques and chemical methods. In addition, the structures of withanolides 1, 2, 3, and 6 were confirmed by X-ray crystallographic analysis. Using a MTS viability assay, eight withanolides (1, 2, 3, 7, 8, 15, 16, and 19) and four acetylated derivatives (1a, 1b, 2a, and 2b) showed potent cytotoxicity against human head and neck squamous cell carcinoma (JMAR and MDA-1986), melanoma (B16F10 and SKMEL-28), and normal fetal fibroblast (MRC-5) cells with IC50 values in the range between 0.067 and 9.3 μM

Efficient perovskite solar cells by metal ion doping

Realizing the theoretical limiting power conversion efficiency (PCE) in perovskite solar cells requires a better understanding and control over the fundamental loss processes occurring in the bulk of the perovskite layer and at the internal semiconductor interfaces in devices. One of the main challenges is to eliminate the presence of charge recombination centres throughout the film which have been observed to be most densely located at regions near the grain boundaries. Here, we introduce aluminium acetylacetonate to the perovskite precursor solution, which improves the crystal quality by reducing the microstrain in the polycrystalline film. At the same time, we achieve a reduction in the non-radiative recombination rate, a remarkable improvement in the photoluminescence quantum efficiency (PLQE) and a reduction in the electronic disorder deduced from an Urbach energy of only 12.6 meV in complete devices. As a result, we demonstrate a PCE of 19.1% with negligible hysteresis in planar heterojunction solar cells comprising all organic p and n-type charge collection layers. Our work shows that an additional level of control of perovskite thin film quality is possible via impurity cation doping, and further demonstrates the continuing importance of improving the electronic quality of the perovskite absorber and the nature of the heterojunctions to further improve the solar cell performance

Impact of H1N1 on Socially Disadvantaged Populations: Systematic Review

The burden of H1N1 among socially disadvantaged populations is unclear. We aimed to synthesize hospitalization, severe illness, and mortality data associated with pandemic A/H1N1/2009 among socially disadvantaged populations.Studies were identified through searching MEDLINE, EMBASE, scanning reference lists, and contacting experts. Studies reporting hospitalization, severe illness, and mortality attributable to laboratory-confirmed 2009 H1N1 pandemic among socially disadvantaged populations (e.g., ethnic minorities, low-income or lower-middle-income economy countries [LIC/LMIC]) were included. Two independent reviewers conducted screening, data abstraction, and quality appraisal (Newcastle Ottawa Scale). Random effects meta-analysis was conducted using SAS and Review Manager.Sixty-two studies including 44,777 patients were included after screening 787 citations and 164 full-text articles. The prevalence of hospitalization for H1N1 ranged from 17-87% in high-income economy countries (HIC) and 11-45% in LIC/LMIC. Of those hospitalized, the prevalence of intensive care unit (ICU) admission and mortality was 6-76% and 1-25% in HIC; and 30% and 8-15%, in LIC/LMIC, respectively. There were significantly more hospitalizations among ethnic minorities versus non-ethnic minorities in two studies conducted in North America (1,313 patients, OR 2.26 [95% CI: 1.53-3.32]). There were no differences in ICU admissions (n = 8 studies, 15,352 patients, OR 0.84 [0.69-1.02]) or deaths (n = 6 studies, 14,757 patients, OR 0.85 [95% CI: 0.73-1.01]) among hospitalized patients in HIC. Sub-group analysis indicated that the meta-analysis results were not likely affected by confounding. Overall, the prevalence of hospitalization, severe illness, and mortality due to H1N1 was high for ethnic minorities in HIC and individuals from LIC/LMIC. However, our results suggest that there were little differences in the proportion of hospitalization, severe illness, and mortality between ethnic minorities and non-ethnic minorities living in HIC