Variation of quantum well infrared photodetectors parameter with an applied electric field

A model is presented for the performance of quantum well infrared photodetectors (QWIPs) utilizing intersubband electron transitions and tunneling injection electrons. The dark current and the responsivity are derived as functions of the QWIP parameters, including the number of the QWs and electric field dependent capture probability in an analytical form. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2789

Hexaaquazinc(II) dinitrate bis[5-(pyridinium-3-yl)tetrazol-1-ide]

Indexación: Scopus.Funding for this research was provided by: Fondecyt Regular (award No. 1151527); Proyecto REDES ETAPA INICIAL, Convocatoria 2017 (award No. REDI170423); Millennium Institute for Research in Optics (MIRO); Basal USA (award No. 1799).Hexaaquazinc(II) dinitrate 5-(pyridinium-3-yl)tetrazol-1-ide, [Zn(H2 O)6](NO 3)2 ·2C6H5 N 5, crystallizes in the space group P. The asymmetric unit contains one zwitterionic 5-(pyridinium-3-yl)tetrazol-1-ide molecule, one NO3-anion and one half of a [Zn(H2 O)6]2+ cation (symmetry). The pyridinium and tetrazolide rings in the zwitterion are nearly coplanar, with a dihedral angle of 5.4 (2)°. Several O-H..N and N-H..O hydrogen-bonding interactions exist between the [Zn(H2 O)6]2+ cation and the N atoms of the tetrazolide ring, and between the nitrate anions and the N-H groups of the pyridinium ring, respectively, giving rise to a three-dimensional network. The 5-(pyridinium-3-yl)tetrazol-1-ide molecules show parallel-displaced π-π stacking interactions; the centroid-centroid distance between adjacent tetrazolide rings is 3.6298 (6) Å and that between the pyridinium and tetrazolide rings is 3.6120 (5) Å. © 2018 Chi-Duran et al.http://journals.iucr.org/e/issues/2018/09/00/cq2025/index.htm

Morpho-physiological and Molecular Variability in Salt Tolerant and Susceptible Popular Cultivars and their Derivatives at Seedling Stage and Potential Parental Combinations in Breeding for Salt Tolerance in Rice

Saltol, a major QTL for salt exclusion, was derived from ‘Pokkali’, a salt-tolerant rice cultivar. Apart from Pokkali, many genotypes with wide variation for salinity tolerance offer ample scope for identifying new genes or QTLs underlying various tolerance mechanisms. Such genes could be aggregated into high-yielding backgrounds to reinforce a breeding programme. To identify potential donors for salt tolerance and prospective parental combinations for developing high-yielding salt-tolerant cultivars, ten genotypes were subjected to salt stress and evaluated for morpho-physiological traits and marker-allele polymorphism in the Saltol-QTL region. Although the salt-susceptible high-yielding varieties clustered together in a 3-D plot, principal component analysis showed marked spatial isolation among the tolerant genotypes. Unlike Pokkali and its derivative FL496, Rahspunjar maintained a higher level of K+ despite high Na+ influx in shoots. The wider genetic distances observed at both phenotypic and genotypic levels suggest the possibility of getting transgressive segregants among the offspring of crosses between Rahspunjar and Gayatri or Swarna Sub1. Similarly, SR 26B, which coped with the stress by diluting the Na+ load by maintaining a higher growth rate, differed from Pokkali or Nona Bokra: these two coped with the stress by regulating the transmission of Na+ from roots to photosynthetically active sites. The F2:3 population derived from Savitri × SR 26B showed wide morpho-physiological diversity for salt tolerance. SR 26B was the most distant genotype from Pokkali in the Saltol QTL region and was salt tolerant despite the absence of Pokkali alleles in this region

Electronic Structure of Calcium Hexaboride within the Weighted Density Approximation

We report calculations of the electronic structure of CaB$_6$ using the weighted density approximation (WDA) to density functional theory. We find a semiconducting band structure with a sizable gap, in contrast to local density approximation (LDA) results, but in accord with recent experimental data. In particular, we find an $X$-point band gap of 0.8 eV. The WDA correction of the LDA error in describing the electronic structure of CaB$_6$ is discussed in terms of the orbital character of the bands and the better cancelation of self-interactions within the WDA.Comment: 1 figur

Variation of quantum well infrared photodetectors parameter with an applied electric field

A model is presented for the performance of quantum well infrared photodetectors (QWIPs) utilizing intersubband electron transitions and tunneling injection electrons. The dark current and the responsivity are derived as functions of the QWIP parameters, including the number of the QWs and electric field dependent capture probability in an analytical form. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2789

Anisotropic two-dimensional Heisenberg model by Schwinger-boson Gutzwiller projected method

Two-dimensional Heisenberg model with anisotropic couplings in the $x$ and $y$ directions ($J_x \neq J_y$) is considered. The model is first solved in the Schwinger-boson mean-field approximation. Then the solution is Gutzwiller projected to satisfy the local constraint that there is only one boson at each site. The energy and spin-spin correlation of the obtained wavefunction are calculated for systems with up to $20 \times 20$ sites by means of the variational Monte Carlo simulation. It is shown that the antiferromagnetic long-range order remains down to the one-dimensional limit.Comment: 15 pages RevTex3.0, 4 figures, available upon request, GWRVB8-9

Hemolytic and DNA binding studies of divalent transition metal ion based macrocyclic complexes

New tetra-azamacrocyclic complexes of Ni (II) and Cu(II) have been synthesized by template methodology leading to the formation of complex of type [MLX2] where L is a macrcocyclic ligand obtained from the condensation of 4-Methyl-o-phenylenediamine (DAT) and 1,3-diphenylpropane-1,3-dione (DBM)and X= NO3-, Cl-, and CH3COO-. Characterization of newly prepared complexes has been  done by using various physico-analytical techniques like UV-visible, IR, ESR, CHN, Magnetic susceptibilities and PXRD.The non-electrolytic nature of the complexes was elucidated by lower value of molar conductance. The data received from various techniques give an indication towards the octahedral geometry of the complexes. The macrocyclic ring is present at the equatorial position whereas the axial positions are occupied by the ligands Cl-, NO3- and CH3COO-. Screening of all the complexes has been performed against the pathogenic strains of microbes in order to check their antimicrobial potential. Invitro-hemolytic activity reveals about the extent to which lyses of hemoglobin takes place. The Herring fish sperm DNA interaction studies are carried out with the help of UV-absorption spectra. Molecular modeling was done through the assistance of  software Chem 3D Ultra that gives the energy calculation and their quantum chemical parameter

New records of desmids from Ropar wetland (a Ramsar Site) of Punjab, India

This study deals with exploration of freshwater desmids for the first time from Ropar wetland (Ramsar site) of Punjab (India) to assess their taxonomic aspects and bio-geographical distribution. During this study, samples of planktonic, epiphytic and epilithic desmids were collected from littoral zone and were observed under light microscope for their morphometric characteristics based identification. Total 21 desmids species belonging to 4 genera of 2 families (Closteriaceae and Desmidiaceae) were identified from the collected samples. Among them, Cosmarium with 11 species (C. awadhense, C. bioculatum, C. trilobatum, C. divergens, C. granatum, C. moniliforme, C. nitidulum, C. subtumidum, C. reniforme, C. undulatum and C. obtusatum) was found to be most abundant followed by Closterium with 7 species (C. acerosum, C. dianae, C. incurvum, C. leibleinii, C. lunula, C. pritchardianum and C. aciculare), Euastrum with 2 species (E. spinulosum and E. platycerum) and Staurastrum with 1 species (S. crenulatum). The geographic distribution of identified desmid taxa in India has been also recorded. All the desmid taxa identified during this study are new record for the Punjab state of India. The results of this study provide significant baseline data for the future taxonomic and ecological studies from the similar habitats