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This paper presents the design and simulations of 5 nm HEMT. The analysis of analog parameters, electrical parameters and the RF performance of the 5 nm HEMT has been done using SILVACO TCAD tool. Here we have designed the HEMT with different materials such as AlGaAs /GaAs / SiC and the high k dielectric material HfO2. The drain current Ids aquired for the HfO2 dielectric material in the 5 nm technology HEMT is 1.4 × 10-7Amperes which is efficient when contrast with SiO2 dielectric. The DIBL value obtained is 0.12 mV/V.By using SILVACO we have measured the transfer and output characteristic plots, threshold voltage(Vth), transconductance(Gm), cut-off frequency, saturation current(Idss). The short channel effects are minimized and the designed structure can be used at high frequency applications. [ABSTRACT FROM AUTHOR]

Alloys based on bismuth telluride (Bi2Te3) form an important class of thermoelectric materials used in Peltier cooling devices and thermoelectric generators. In this work, polycrystalline n-type Bi2Te3 alloy was prepared by a melt-quenching process using different quenching mediums: alkaline ice water, ice water, normal water, liquid nitrogen, and air-cooling. The relation between melt solidification rate and structural and thermoelectric transport properties of Bi2Te3 alloy were studied. The pure phase of Bi2Te3 is confirmed by structural characterizations: XRD and Raman. This study showed that the melt solidification rate has a consequential role in modulating the microstructure and thermoelectric transport properties. The moderate cooling rate of melt solidification showed the highest zT of ~ 0.06 at 423 K due to higher defect density. This study attempts to explain the different zT values observed for different quenching mediums. [ABSTRACT FROM AUTHOR]

Fe deficiency is a major challenge that limits agricultural productivity and is a serious human health concern worldwide. Under iron-limiting conditions soil microorganisms produce siderophores, that chelates Fe3+ (ferric) and make it available to the plants. Selection of efficient siderophore producing bacteria and establishing their role in enhancing iron uptake is a strategic approach for improving plant nutrition. Hence 3 efficient isolates Pantoea agglomerans, Pseudomonas plecoglossida and Lactococcus lactis, selected from a repository of 154 bacteria, producing catecholate, hydroxamate and carboxylate siderophores, respectively, were assessed for Fe chelation efficiency using 59Fe and their role in plant biometric parameters, Fe uptake and antioxidant enzymes with tomato (Strategy I) and wheat (Strategy II) test plants under hydroponic system. Cell-free siderophore preparation (Sid) improved plant parameters and iron nutrition more efficiently than bacterial inoculants. Pantoea agglomerans was proven best as its 59Fe-bound siderophore complex showed the highest uptake of 4.25 and 1.59 Bq plant−1 in wheat and tomato, respectively. Further, the Fe-starved plants (1 µm Fe-EDTA) showed around two-fold higher 59Fe uptake than those raised under Fe-sufficient condition (100 µm Fe-EDTA). Results indicated that probably the bacterial mediated iron translocation in plants is Strategy III, complementing both Strategy I and II by facilitating higher availability of chelated Fe to plant reductases directly and/or through ligand exchange with phytosiderophores, respectively. This study highlights the need for integration of siderophore based formulations in INM strategies for enhancing plant iron content to address the Fe deficiency challenge of the soil and human nutrition. [ABSTRACT FROM AUTHOR]

Membrane technology is an advanced approach to making a healthier and cleaner environment. Using such catalytic membrane technology to get clean, usable water by removal of dye impurities as well as pathogenic microbes is the main goal behind the research work. Here, we present the synthesis and efficacy study of polymethyl methacrylate (PMMA)-based Ag/ZnO/TiO2 trimetallic bifunctional nanofibers with antibacterial and photocatalytic activity. The nanofibers have been proven to be effective for the degradation of methylene blue (MB 93.4%), rhodamine B (Rh 34.6%), auramine-O (Au 65.0%) and fuchsin basic (FB 69.8%) dyes individually within 90 min in daylight. The study is further extended in abating a mixture of these dyes from contaminated water using composite nanofibers. Also, in the case of a mixture of these dyes (3 ppm each), nanofibers show dye degradation efficiency (DDE) of 90.9% (MB), 62.4% (Au) and 90.3% (FB and Rh) in 60 min. The role of Ag nanoparticles with a synergic photocatalytic effect on ZnO and TiO2 is also demonstrated. Also, PMMA/ZnO/TiO2 composite fiber membrane in synergy with silver particles shows better antibacterial activity against Gram-negative bacteria E. coli, making PMMA/Ag/ZnO/TiO2 fibers a promising candidate in water purification. [ABSTRACT FROM AUTHOR]

Genetic and functional diversity of osmotolerant bacterial endophytes colonizing the root, stem, and leaf tissues of pearl millet genotypes differing in their drought susceptibility was assessed. Two genotypes of pearl millet, viz., the drought tolerant genotype TT-1 and the drought susceptible genotype PPMI-69, were used in the present study. Diazotrophs were found to be the predominant colonizers, followed by the Gram positive bacteria in most of the tissues of both the genotypes. Higher proportion of bacterial endophytes obtained from the drought tolerant genotype was found to be osmotolerant. Results of 16S rRNA gene-ARDRA analysis grouped 50 of the highly osmotolerant isolates into 16 clusters, out of which nine clusters had only one isolate each, indicating their uniqueness. One cluster had 21 isolates and remaining clusters were represented by isolates ranging from two to four. The representative isolates from each cluster were identified, and Bacillus was found to be the most prevalent osmotolerant genera with many different species. Other endophytic bacteria belonged to Pseudomonas sp., Stenotrophomonas sp., and Macrococcus caseolyticus. High phylogenetic diversity was observed in the roots of the drought tolerant genotype while different tissues of the drought susceptible genotype showed less diversity. Isolates of Bacillus axarquiensis were present in all the tissues of both the genotypes of pearl millet. However, most of the other endophytic bacteria showed tissue/genotype specificity. With the exception of B. axarquiensis and B. thuringiensis, rest all the species of Bacillus were found colonizing only the drought-tolerant genotype; while M. caseolyticus colonized all the tissues of only the drought susceptible genotype. There was high incidence of IAA producers and low incidence of ACC deaminase producers among the isolates from the root tissues of the drought-tolerant genotype while reverse was the case for the drought-susceptible genotype. Thus, host played an important role in the selection of endophytes based on both phylogenetic and functional traits. [ABSTRACT FROM AUTHOR]

A broad and intense visible as well as NIR luminescence is obtained from bismuth ions doped in alkali-free Ba-Al metaphosphate glasses. The glasses with varied bismuth oxide content have been prepared by melt quenching technique. With increase in bismuth concentration, the NIR emitting centers are found to be dominant, while at lower concentrations no NIR emission is perceived. The visible emission covers significant portion of the visible solar spectrum, while the NIR band obtained is much blue-shifted as compared to other host matrices. FTIR reflection spectroscopy studies elucidate that the dopant bismuth plays the role of a network modifier and weaken the network by formation of NBOs and P-O-Bi bonds at the expense of [PO] bonds. The excitation and emission spectra indicate the presence of bismuth in multiple valence state, mainly as Bi, Bi, and Bi. The visible and NIR emissions are arising from different luminophore centers of dopant ions that are getting simultaneously excited. [ABSTRACT FROM AUTHOR]

Bacteria capable of degrading the sulfonated azo dye Red HE7B were isolated from textile mill effluent contaminated soil. The most efficient isolate was identified as Bacillus sp. Azo1 and the isolate could successfully decolorize up to 89 % of the dye. The decolorized cultural extract analyzed by HPLC confirmed degradation. Enzymatic analysis showed twofold and fourfold increase in the activity of azoreductase and laccase enzymes, respectively, indicating involvement of both reductive and oxidative enzymes in biodegradation of Red HE7B. Degraded products which were identified by GC/MS analysis included various metabolites like 8-nitroso 1-naphthol, 2-diazonium naphthalene. Mono azo dye intermediate was initially generated from the parent molecule. This mono azo dye was further degraded by the organism, into additional products, depending on the site of cleavage of R-N=N-R molecule. Based on the degradation products identified, three different pathways have been proposed. The mechanism of degradation in two of these pathways is different from that of the previously reported pathway for azo dye degradation. This is the first report of a microbial isolate following multiple pathways for azo dye degradation. Azo dye Red HE7B was observed to be phytotoxic, leading to decrease in root development, shoot length and seedling fresh weight. However, after biotreatment the resulting degradation products were non-phytotoxic. [ABSTRACT FROM AUTHOR]

High energy, high power (HEHP) Nd:glass laser systems are used for inertial confinement fusion and equation of state (EOS) studies of materials at high temperature and pressure. A program has been undertaken for the indigenous development of Nd-doped phosphate laser glass rods and discs for HEHP lasers. In this paper, we report the characterization of the Nd-doped phosphate laser glass rods produced under this program and compare the indigenously developed laser glass to LHG-8 laser glass of M/s Hoya, Japan. We experimentally measured the values of the stimulated emission cross-section ( σ) and coefficient of intensity-dependent refractive index ( n) and hence the figure of merit F = σ / n of the indigenous phosphate laser glass rods. This value is found comparable to the reported value of identically doped Nd:glass rods. [ABSTRACT FROM AUTHOR]

Europium doped glass-ceramics containing BaF nano-crystals have been prepared by using the controlled crystallization of melt-quenched glasses. X-ray diffraction and transmission electron microscopy have confirmed the presence of cubic BaF nano-crystalline phase in glass matrix in the ceramized samples. Incorporation of rare earth ions into the formed crystalline phase having low phonon energy of 346 cm has been demonstrated from the emission spectra of Eu ions showing the transitions from upper excitation states D (J = 1, 2, and 3) to ground states for the glass-ceramics samples. The presence of divalent europium ions in glass and glass-ceramics samples is confirmed from the dominant blue emission corresponding to its 5d-4f transition under an excitation of 300 nm. Increase in the reduction of trivalent europium (Eu) ions to divalent (Eu) with the extent of ceramization is explained by charge compensation model based on substitution defect mechanisms. Further, the phenomenon of energy transfer from Eu to Eu ion by radiative trapping or re-absorption is evidenced which increases with the degree of ceramization. For the first time, the reduction of Eu to Eu under normal air atmospheric condition has been observed in a BaF containing oxyfluoride glass-ceramics system. [ABSTRACT FROM AUTHOR]

Glucose, maltose, and mannose as sole carbon sources, induced synthesis of glucose dehydrogenase (GDH) in three strains of Pantoea with specific activities from 0.14 to 0.6 U/mg proteins. Utilization of lactose indicated that the enzyme belongs to GDH type B isozyme. Of mutant clones, developed through radiation mutagenesis, P2-M2 utilized ribose with GDH specific activity of 0.57 U/mg protein, P4-M3 grown on glucose gave 1.5 U/mg protein and P4-M5 had high activities, when grown on galactose, maltose, and lactose. Clones P3-M2 and P2-M5 had versatile utilization of sugars and released higher amounts of P from tri-calcium phosphate and can be efficiently used for biofertilization. [ABSTRACT FROM AUTHOR]

Glasses in the composition of 25KO-25NbO-50SiO (mol %) have been prepared by melt quenching technique and isothermally heat-treated at 800 °C for different duration (0-200 h). The formed nanocrystalline KNbO phase, crystallite size and morphology are examined by X-ray diffraction, Fourier transform infrared reflection spectroscopy, field emission scanning and transmission electron microscopes. The frequency and temperature dependent dielectric constant and loss tangent are measured in the frequency and temperature ranges 0.1-1000 kHz and 200-500 °C respectively. The dielectric constant and loss tangent are found to decrease with increasing frequency and increase with increasing temperature. The dielectric constant and loss tangent versus temperature curve at different frequency revealed the phase transition of KNbO from paraelectric cubic to ferroelectric tetragonal around 425 and 397 °C (Curie temperature) for nano glass-ceramics obtained after 1 and 200 h heat-treatment respectively. [ABSTRACT FROM AUTHOR]

Impact of wastewater irrigation on some biological properties was studied in an area where treated sewage water is being supplied to the farmers since 1979 in the western part of National Capital Territory of New Delhi under Keshopur Effluent Irrigation Scheme. Three fields were selected which had been receiving irrigation through wastewater for last 20, 10 and 5 years. Two additional fields were selected in which the source of irrigation water was tubewell. The soil bacterial and fungal population density was studied in soil layers of 0-15, 15-30, 30-60 and 60-120 cm depths. Groundwater samples were collected from the piezometers installed in the field irrigated with sewage water for last 20, 10 and 5 years. Results indicate that there was significant increase in bacterial and fungal count in sewage-irrigated soils as compared to their respective control. The population density of bacteria and fungi in waste water-irrigated soils increased with the duration of sewage water application and decreased with increasing depth. The bacterial and fungal count was also directly proportional to organic carbon, sand and silt content and negatively correlated to the clay content, electrical conductivity, pH and bulk density of the soil. Groundwater under sewage-irrigated fields had higher values of most probable number (MPN) index as compared to that of tubewell water-irrigated fields. All the shallow and deep groundwaters were found to be contaminated with faecal coliforms. The vadose zone had filtered the faecal coliform to the tune of 98-99%, as the MPN index was reduced from ≥18,000 per 100 ml of applied waste water to 310 per 100 ml of groundwater under 20 years sewage-irrigated field. The corresponding values of MPN were 250 and 130 per 100 ml of shallow groundwater under 10 and 05 years sewage-irrigated fields, respectively. Rapid detection of faecal contamination suggested that the Citrobacter freundii and Salmonella were dominant in shallow groundwater, while Escherichia coli was dominant in deep groundwater collected from sewage-irrigated field. [ABSTRACT FROM AUTHOR]

This paper reports the dopant ion (Nd) concentration effects on its luminescence properties in a new glass system based on barium-alumino-metaphosphates. Amongst the studied concentrations range of 0.276-13.31×10 ions/cm, the glass with 2.879×10 ions/cm (1 mol%) Nd concentration shows intense NIR emission from F excited state, followed by a decrease in emission intensity for further increase in Nd ion concentration. The observed luminescence quenching is ascribed to Nd self-quenching through the donor-donor migration assisted cross-relaxation mechanism. The microscopic energy transfer parameters for donor-acceptor energy transfer, C, and donor-donor energy migration, C, have been obtained from the theoretical fittings to experimental decay curves and the spectral overlap model respectively. The C parameters (×10 cm/sec) are found to be about three orders greater than that of C (×10 cm/sec) for Nd self-quenching in this host, demonstrating that the excitation energy migration among donors is due to the hopping mechanism. The energy transfer micoparameters obtained in the present study are comparable to the values reported for commercially available laser glasses LHG-8 and Q-98. [ABSTRACT FROM AUTHOR]

This paper reports results on the crystallization kinetics of 35.5CaO–7.25La2O3–57.25B2O3 glass under nonisothermal conditions based on the studies carried out from the differential thermal analysis upon using various well-established models. The crystalline phases formed during the optimized ceramization process have been confirmed from the X-ray diffraction. The activation energies of the first (formation of CaLaB7O13) and second (formation of LaBO3) crystallization events have been estimated using the conventional methods of Kissinger, Augis–Bennett, Ozawa, and Matusita, and the results are found to be in good agreement with each other. The Avrami exponents that are determined by these models for the crystallization of CaLaB7O13 and LaBO3 are found to be in the range of (1.81–2.35) and (4.03–4.65), respectively. This indicates that the formation of CaLaB7O13 is dominated by a surface crystallization, whereas LaBO3 is formed by three-dimensional bulk crystallization with an increased rate of nucleation. This observation is further validated by microstructural investigation, which shows the formation of CaLaB7O13 phase as a surface layer and a bulk crystallization of LaBO3 in optimally ceramized samples. [ABSTRACT FROM AUTHOR]

A total of 137 bacterial isolates from surface sterilized root, stem, and nodule tissues of soybean were screened for their antifungal activity against major phytopathogens like Rhizoctonia bataticola, Macrophomina phaseolina, Fusarium udam, and S clerotium rolfsii. Nine bacterial endophytes suppressed the pathogens under in vitro plate assay. These were characterized biochemically and identified at the genus level based on their partial sequence analysis of 16S rDNA. Eight of the isolates belonged to Bacillus and one to Paenibacillus. The phylogenetic relationship among the selected isolates was studied and phylogenetic trees were generated. The selected isolates were screened for biocontrol traits like production of hydrogen cyanide (HCN), siderophore, hydrolytic enzymes, antibiotics, and plant growth promoting traits like indole 3-acetic acid production, phosphate solubilization, and nitrogen fixation. A modified assessment scheme was used to select the most efficient biocontrol isolates Paenibacillus sp . HKA-15 (HKA-15) and Bacillus sp. HKA-121 (HKA-121) as potential candidates for charcoal rot biocontrol as well as soybean plant growth promotion. [ABSTRACT FROM AUTHOR]

This paper reports on the results concerning optical absorption and fluorescence properties of 60TeO2–25ZnO–10BaO–4.5La2O3–0.5Pr2O3 (Pr3+: TZBL) glass. Both electronic (αe) and vibrational (αv) band edge cut-off wavelengths of the host glass (TZBL) have been evaluated from the measurement of its UV–Vis and IR transmission spectra. The glass studied has shown 80% transmittance throughout its optical window from 0.366 μm (αe = 3.39 eV) to 6.30 μm (αv = 0.197 eV). The FT-IR transmission spectra of Pr3+ doped and also reference tellurite glasses have demonstrated the presence of TeO4 and TeO3+1 or TeO3 structural units. The thermal properties of this glass have been investigated from the study of DTA profile. The recorded optical absorption spectra of Pr3+: TZBL glass have shown eight absorption bands from 300 nm to 2,500 nm. The fluorescence emission has been observed mainly from 3P1, 3P0 and 1D2 states to the lower lying states and which are assigned to the transitions of 3P0→ 3H4,5,6; 3P0→ 3F2,3,4; 3P1→3H5 & 1D2→3H4,5 upon excitations at three excitation states of 3P0,1,2. From the time resolved spectra, it is found that 3P0 level decays faster than 1D2 level. The fluorescence decay kinetics of 3P0 and 1D2 levels have been measured and the lifetimes are found to be 21 and 39 μs, respectively. [ABSTRACT FROM AUTHOR]

Four defective (AFM−) mutants of Paenibacillus sp. HKA-15 that no longer produced the peptide antifungal metabolites were developed through ethyl methane sulfonate (EMS) mutagenesis and used for in vivo experimentation. Reduced percentage of seed germination by mutants DM1 and DM2 (22.5% and 25%, respectively) and a high percent of disease incidence (69.3% and 67%, respectively) compared to wild-strain HKA-15 (80% seed germination and 27% disease incidence) indirectly indicated the role of peptide metabolite on disease suppression. Plants treated with AFM− clones showed stunted growth and the presence of pepperlike microsclerotia in the stem tissues. Light and scanning electron microscopic studies clearly showed the effect of peptide antibiosis on hyphal morphology. Exposure to crude extracts of antibiotics produced abnormal contraction of fungal cytoplasm, granulation, and fragmentation of hyphal mycelia and cell lysis. The presence of bacterial cells in the lumen of degrading fungal mycelium suggested a direct involvement of Paenibacillus sp. HKA-15 in the lysis of Rhizoctonia bataticola. [ABSTRACT FROM AUTHOR]

Sixty root nodule isolates of soybean rhizobia indigenous to eight field sites in India were characterized using PCR-RFLP for repeated sequence RSα a 1195-bp DNA fragment, indole acetic acid production, and nitrogenase activity. Site-dependent variations were observed in terms of IAA production and nitrogenase activities. RSα was conserved in slow-growing soybean rhizobia across locations and sites and was absent in other Rhizobiaceae members and other bacterial genera. The results suggest that RSα can be a useful molecular marker for slow-growing soybean rhizobia. The study also showed the low presence of soybean nodulating fast growers in Indian soils. [ABSTRACT FROM AUTHOR]

Foliar spray and micro-injection of plant growth-promoting rhizobacterial species, viz. Pseudomonas fluorescens and P. aeruginosa on chickpea induced synthesis of phenylalanine ammonia-lyase (PAL) when tested against Sclerotinia sclerotiorum. Induction of PAL was also associated with increased synthesis of phenolic compounds such as tannic, gallic, caffeic, chlorogenic and cinnamic acids. Treatment with P. fluorescens was found to be more effective in inducing phenolic compounds as compared to P. aeruginosa. However, persistence of PAL activity was observed more with P. aeruginosa. Although both the inoculation methods were effective, foliar application was found to be superior to micro-injection in terms of rapid PAL activity leading to the synthesis of phenolic compounds. [ABSTRACT FROM AUTHOR]

Presents a letter to the editor about the emission spectra of heavy metal oxide glasses based on bismuth compounds.

Reports on results of the excitation and emission spectra and lifetimes of manganese containing zinc boro silicate glasses measured at ultraviolet radiation excitation. Zinc-borosilicate glasses of chemical composition of 60ZnO-20B2O3-19SiO2-1MnO (mol%) have been prepared by employing the conventional quenching technique; Importance for the development of optoelectronic materials.