460 research outputs found
Unique Design of CuInSe2 Nanocrystal decorated Gold Nanoprism Hybrid Conjugates for Advanced Photocatalytic Application
poster abstractWe present CuInSe2 nanocrystal decorated gold nanoprism hybrid conjugates with advanced photocatalytic ability in order to offer a unique and environmentally sound solution to the current obstacles faced by photovoltaic device materials currently used. A search for clean and abundant energy sources is a major concern for the environmentally conscious scientist. Photocatalytic reactions can harness this energy and use it for a variety of applications including oxidation of organic contaminants, self-cleaning glass, conversion to water as hydrogen glass, and decomposition of crude oil. However solar absorption in these devices is lacking the efficiency needed to be cost effective. Choice of device material is pivotal in overcoming this large hurdle. Materials such as TiO2, the most commonly used semiconductor photocatalyst, for example only absorbs light in the ultraviolet region which accounts for less than 5% of total solar radiation. Hybrid conjugates, or nanomaterials combining semiconductor and metal materials, are a fast growing alternative to this problem. By incorporating localized surface plasmon resonance (LSPR) properties of the metal nanostructures with controllable band gaps of the semiconductor nanocrystals, the material can shift to the visible and near-infrared spectra thus allowing for greater solar absorbance. However, to the best of our knowledge, no reports are available in which plasmonic coupling occurs between a LSPR active metal nanostructures and the tailoring of the semiconductor nanocrystals’ band gap by a non-toxic, low temperature synthesis. Hybrid conjugates between LSPR active metal nanostructures and semiconductor nanostructures have been reported but suffer from cost effectiveness and often use environmentally unfriendly chemicals. We believe our unique hybrid nanomaterial will allow for further tuning of the LSPR peak position in order to extend light absorption to a more optimal window and further excite electron-hole pairs in order to provide the most photocatalytic activity to date while providing an environmentally friendly and cost-effective approach. This work has major implications in clean energy and more specifically the advancement of photocatalytic applications
Synthesis and Recognition Properties of Higher Order Tetrathiafulvalene (Ttf) Calix N Pyrroles (N=4-6)
Two new benzoTTF-annulated calix[n]pyrroles (n = 5 and 6) were synthesized via a one-step acid catalyzed condensation reaction and fully characterized via single crystallographic analyses. As compared to the known tetra-TTF annulated calix[4]pyrrole, which is also produced under the conditions of the condensation reaction, the expanded calix[n]pyrroles (n = 5 and 6) are characterized by a larger cavity size and a higher number of TTF units (albeit the same empirical formula). Analysis of the binding isotherms obtained from UV-Vis spectroscopic titrations carried out in CHCl3 in the presence of both anionic (Cl-, Br-, I-, CH3COO-, H2PO4-, and HSO4-) and neutral (1,3,5-trinitrobenzene (TNB) and 2,4,6-trinitrotoluene (TNT)) substrates revealed that as a general rule the calix[6]pyrrole derivative proved to be the most efficient molecular receptor for anions, while the calix[4]pyrrole congener proves most effective for the recognition of TNB and TNT. These findings are rationalized in terms of the number of electron rich TTF subunits and NH hydrogen bond donor groups within the series, as well as an ability to adopt conformations suitable for substrate recognition, and are supported by solid state structural analyses.National Science Foundation CHE 1057904, 0741973Robert A. Welch Foundation F-1018Danish Natural Science Research Council (FNU) 272-08-0047, 11-106744WCU (World Class University) program of Korea R32-2010-10217-0Villum FoundationChemistr
Investigating the Control by Quantum Confinement and Surface Ligand Coating of Photocatalytic Efficiency in Chalcopyrite Copper Indium Diselenide Nanocrystals
In the past few years, there has been immense interest in the preparation of sustainable photocatalysts composed of semiconductor nanocrystals (NCs) as one of their components. We report here, for the first time, the effects of structural parameters of copper indium diselenide (CuInSe2) NCs on visible light-driven photocatalytic degradation of pollutants under homogeneous conditions. Ligand exchange reactions were performed replacing insulating, oleylamine capping with poly(ethylene glycol) thiols to prepare PEG-thiolate-capped, 1.8–5.3 nm diameter CuInSe2 NCs to enhance their solubility in water. This unique solubility property caused inner-sphere electron transfer reactions (O2 to O2•−) to occur at the NC surface, allowing for sustainable photocatalytic reactions. Electrochemical characterization of our dissolved CuInSe2 NCs showed that the thermodynamic driving force (−ΔG) for oxygen reduction, which increased with decreased NC size, was the dominant contributor to the overall process when compared to ..
Diversity of Birds Fauna in Jhargram, West Bengal, India
Jhargram is a newly formed district, separated from Paschim Medinipur district on 4th April, 2017. The biodiversity of Jhargram is very rich, especially on avifaunal diversity due to its well vegetation, less human interference, low pollution level and good environmental health. The following paper represents the survey report on birds for two years, annotated checklist of bird species with Latin name and IUCN status, graphical representation of species composition on different families, study area and study protocol, devices used and some interesting photographs that collect during field surveys. The exhaustive field study showed 132 species in 109 genera under 58 families within 20 orders from Jhargram town and its outskirts. Some avian species are local migrant, while some are long distant migrant, occasional dweller, and maximum are resident. The rich diversity indicates a good environmental quality, lower pollution rate. This is the first hand study that reveals avifaunal diversity from Jhargram for first time and some rare species of birds from Jhargram are reported on this article
A study on the effects of 6 weeks of training on body composition, physical fitness and physiological variables of female football players
Background: Female football becomes popular in last decades. The body fat, strength, power, endurance etc are playing an important role in female football. The present study has been designed to investigate the effects of 6 weeks of training on body composition, physical fitness and physiological variables of female football players. Materials and Methods: A total of eighty two female football players (age 16-18 yrs.) participated were included and twenty two were excluded from the study, the remaining were divided into control group (CG, n = 30) and experimental group (EG, n = 30). The volunteers of the experimental group followed a training programme (2 hrs/day, 5day/week, for 6 weeks), whereas no training was given volunteers of the control group. Selected body composition, physical fitness and physiological variables were performed at the beginning (0 week) and at the end of the study (6 weeks). Results: A significant reduction (p < .05) in body mass, body fat, resting heart rate, recovery heart rate, and systolic blood pressure; and an increase (p < .05) in strength, anaerobic power, VO2max, FEV1, FVC and PEFR was noted after 6 weeks of training. Body fat showed negative correlation with back strength (r = - 0.26, p < .05), grip strength (r = -0.46, p < .01), anaerobic capacity (r = -0.30, p < .05) and flexibility (r = -0.32, p < .05) of the volunteers. LBM showed positive correlation with grip strength right (r = 0.59, p < .05), grip strength left (r = 0.53, p < .05), back strength (r = 0.73, p < .05), flexibility (r = 0.41, p < .05). The anaerobic power showed a significant positive correlation with VO2max (r = 0.51, p < .01). Conclusions: Regular monitoring of the indicators is essential to obtain optimal performance of the players
A new strategy for improvement of tamarind seed based chicken diet after microbial detannification and assessment of its safety aspects
Tamarind seed, an abundant agricultural waste, contains a large amount of naturally occurring anti-nutrient, tannin. This study aimed at evaluating the detannification efficiency of tannase producing Bacillus subtilis PAB2 in comparison with enzymatic and conventional physical techniques, and assessment of its health promoting effect in chicken model. Microbial fermentation resulted in lowering of 80.8% tannin, whereas enzymatic and physical treatment removed only 48 and 28.6%, respectively. To assess the health beneficial effects, experimental schedule for poultry chicken model was designed viz., (T1) commercial food, (T2) T1+tamarind seeds, (T3) T1+enzymatic detannified seeds and (T4) T1+ fermented seeds. It was found that physiological indices of chicken in T4 group improved more than T2, but those were comparable with T1 and T3. The level of total plasma protein, albumin and other haematological parameters also significantly (P<0.05) improved in T4 more than T2. The quantities of small intestinal indicator microbes like Escherichia coli, Clostridium perfringens and Yeast sp. in T4 group increased more than T2. Thus, fermentation led to quality improvement of raw tamarind seed which suggested its employment as an alternative feedstock for poultry chicken
Stabilization of halide perovskites with silicon compounds for optoelectronic, catalytic, and bioimaging applications
Silicon belongs to group 14 elements along with carbon, germanium, tin, and lead in the periodic table. Similar to carbon, silicon is capable of forming a wide range of stable compounds, including silicon hydrides, organosilicons, silicic acids, silicon oxides, and silicone polymers. These materials have been used extensively in optoelectronic devices, sensing, catalysis, and biomedical applications. In recent years, silicon compounds have also been shown to be suitable for stabilizing delicate halide perovskite structures. These composite materials are now receiving a lot of interest for their potential use in various real‐world applications. Despite exhibiting outstanding performance in various optoelectronic devices, halide perovskites are susceptible to breakdown in the presence of moisture, oxygen, heat, and UV light. Silicon compounds are thought to be excellent materials for improving both halide perovskite stability and the performance of perovskite‐based optoelectronic devices. In this work, a wide range of silicon compounds that have been used in halide perovskite research and their applications in various fields are discussed. The interfacial stability, structure–property correlations, and various application aspects of perovskite and silicon compounds are also analyzed at the molecular level. This study also explores the developments, difficulties, and potential future directions associated with the synthesis and application of perovskite‐silicon compounds. imag
Ethnic Preparation of Haria, a Rice-Based Fermented Beverage, in the Province of Lateritic West Bengal, India
Haria is a rice-based fermented beverage that is popular among tribal and low income people in lateritic West Bengal and East-Central India. The principal ingredient of this beverage is low grade boiled rice (Oryza sativa L.), which is mixed with a traditional starter, called bakhar, and fermented within a heat-sterilized earthen pot for 3-4 days. The main aim of this study was to investigate the ethnobotanical importance and traditional process of haria preparation. The method adopted for this study was based on interactive questionnaires and laboratory experiments. It was found that the pH decreased during the course of fermentation with increased titratable acidity of 1.42%. The alcohol content was 2-3% (v/v) in the consumable beverages. This documentation will be useful for further exploitation of haria as a health drink
Molecular enneanuclear CuII phosphates containing planar hexanuclear and trinuclear sub-units: syntheses, structures, and magnetism
Highly symmetric enneanuclear copper(II) phosphates [Cu9(Pz)6(μ-OH)3(μ3-OH)(ArOPO3)4(DMF)3] (PzH =pyrazole, Ar = 2,6-(CHPh2)2-4-R-C6H2; R = Me, 2MeAr; Et, 2EtAr; iPr, 2iPrAr; and Ar = 2,6-iPr2C6H3, 2Dip) comprising nine copper(II) centers and pyrazole, hydroxide and DMF as ancillary ligands were synthesized by a reaction involving the arylphosphate monoester, 1, copper(I)chloride, pyrazole, and triethylamine in a 4 : 9 : 6 : 14 ratio. All four complexes were characterized by single crystal structural analysis. The complexes contain two distinct structural motifs within the multinuclear copper scaffold: a hexanuclear unit and a trinuclear unit. In the latter, the three Cu(II) centres are bridged by a µ3-OH. Each pair of Cu(II) centers in the trinuclear unit are bridged by a pyrazole ligand. The hexanuclear unit is made up of three dinuclear Cu(II) motifs where the two Cu(II) centres are bridged by an -OH and a pyrazole ligand. The three dinuclear units are connected to each other by phosphate ligands. The latter also aid the fusion of the trinuclear and the hexanuclear motifs. Magnetic studies reveal a strong antiferromagnetic exchange between the Cu(II) centres of the dinuclear units in the hexanuclear part and a strong spin frustration in the trinuclear part leading to a degenerate ground state
- …