2,200 research outputs found
High field CdS detector for infrared radiation
New and highly sensitive method of detecting infrared irradiation makes possible solid state infrared detector which is more sensitive near room temperature than usual photoconductive low band gap semiconductor devices. Reconfiguration of high field domains in cadmium sulphide crystals provides basis for discovery
High field CdS detector for infrared radiation
An infrared radiation detector including a cadmium sulfide platelet having a cathode formed on one of its ends and an anode formed on its other end is presented. The platelet is suitably doped such that stationary high-field domains are formed adjacent the cathode when based in the negative differential conductivity region. A negative potential is applied to the cathode such that a high-field domain is formed adjacent to the cathode. A potential measuring probe is located between the cathode and the anode at the edge of the high-field domain and means are provided for measuring the potential at the probe whereby this measurement is indicative of the infrared radiation striking the platelet
Efficacy of Various IPM Modules on Biotic Pressure and Green Forage Yield in a Forage Production System (Cowpea + BN Hybrid – Berseem mixed with Mustard + BN Hybrid)
Various control measures by themselves are not free from one or the other limitations to provide safe, economically viable and efficient in pest population suppression. The economics is much more relevant when we talk of low value commodity like forage crops. Viewing this multifaceted problem and inherent limitations of each control method the ultimate solution lies in integrated pest control expedient. The connotation of the approach is to utilize all the possible methods of control including maximum exploitation of naturally existing populations and regulating factors in as compatible manner as possible to keep the pest population levels below economic threshold. Earlier, IPM in fodder crops has been worked out by Shri Ram and Gupta, 1989; Pandey et al., 2000; Shah et al., 2011
Flux melting in BSCCO: Incorporating both electromagnetic and Josephson couplings
Multilevel Monte Carlo simulations of a BSCCO system are carried out
including both Josephson as well as electromagnetic couplings for a range of
anisotropies. A first order melting transition of the flux lattice is seen on
increasing the temperature and/or the magnetic field. The phase diagram for
BSCCO is obtained for different values of the anisotropy parameter .
The best fit to the experimental results of D. Majer {\it et al.} [Phys. Rev.
Lett. {\bf 75}, 1166 (1995)] is obtained for provided one
assumes a temperature dependence of the
penetration depth with . Assuming a dependence
the best fit is obtained for . For finite anisotropy the data is shown to collapse on a straight line
when plotted in dimensionless units which shows that the melting transition can
be satisfied with a single Lindemann parameter whose value is about 0.3. A
different scaling applies to the case. The energy jump is
measured across the transition and for large values of it is found to
increase with increasing anisotropy and to decrease with increasing magnetic
field. For infinite anisotropy we see a 2D behavior of flux droplets with a
transition taking place at a temperature independent of the magnetic field. We
also show that for smaller values of anisotropy it is reasonable to replace the
electromagnetic coupling with an in-plane interaction represented by a Bessel
function of the second kind (), thus justifying our claim in a previous
paper.Comment: 12 figures, revtex
Hydrogeological and Hydrochemical Characterization of Coastal Aquifers with Special Reference to Submarine Groundwater Discharge in Uttara Kannada, Karnataka, India
In coastal areas of our country, in spite of having excess rainfall (more than 3000 mm), groundwater become a rare commodity during summer. Number of researchers have discussed the issues related to water scarcity of coastal areas where there is a huge pressure on environment due to increased population, tourism, agriculture and industrial growth. Fast depletion of groundwater is also reported in coastal districts due to continuous discharge of direct runoff and also through subterranean flow which is termed as Submarine Groundwater Discharges (SGD). Large quantity of contaminants enter the ocean system through runoff. This necessitated a detailed investigation to understand the hydrological processes involved and the source of contaminants. The present investigation is an attempt to make quantitative and qualitative assessment of SGD based on hydrological, hydrogeological and hydrochemical components. Accordingly, water balance components were evaluated based on hydrological and hydrogeological investigations. Hydrochemical parameters were also evaluated to understand the impact of seawater intrusion in pre and postmonsoon of 2019. Study revealed that, there are signatures of considerable quantity of submarine groundwater discharge in parts of Honnavara, Kumta, Ankola and Karwar talukas. The influence of seawater in coastal aquifers is quite rare all along the coast of Uttara kannada district which is attributed to high groundwater recharge (15-20%) occurring in catchment areas
Practical long-distance quantum key distribution system using decoy levels
Quantum key distribution (QKD) has the potential for widespread real-world
applications. To date no secure long-distance experiment has demonstrated the
truly practical operation needed to move QKD from the laboratory to the real
world due largely to limitations in synchronization and poor detector
performance. Here we report results obtained using a fully automated, robust
QKD system based on the Bennett Brassard 1984 protocol (BB84) with low-noise
superconducting nanowire single-photon detectors (SNSPDs) and decoy levels.
Secret key is produced with unconditional security over a record 144.3 km of
optical fibre, an increase of more than a factor of five compared to the
previous record for unconditionally secure key generation in a practical QKD
system.Comment: 9 page
Optical Properties of Mono-Dispersed AlGaN Nanowires in the Single-Prong Growth Mechanism
Growth of mono-dispersed AlGaN nanowires of ternary wurtzite phase is
reported using chemical vapour deposition technique in the vapour-liquid-solid
process. The role of distribution of Au catalyst nanoparticles on the size and
the shape of AlGaN nanowires are discussed. These variations in the morphology
of the nanowires are understood invoking Ostwald ripening of Au catalyst
nanoparticles at high temperature followed by the effect of single and
multi-prong growth mechanism. Energy-filtered transmission electron microscopy
is used as an evidence for the presence of Al in the as-prepared samples. A
significant blue shift of the band gap, in the absence of quantum confinement
effect in the nanowires with diameter about 100 nm, is used as a supportive
evidence for the AlGaN alloy formation. Polarized resonance Raman spectroscopy
with strong electron-phonon coupling along with optical confinement due to the
dielectric contrast of nanowire with respect to that of surrounding media are
adopted to understand the crystalline orientation of a single nanowire in the
sub-diffraction limit of about 100 nm using 325 nm wavelength, for the first
time. The results are compared with the structural analysis using high
resolution transmission microscopic study.Comment: 33 pages, 7 figures, journa
Nitrogen partitioning and remobilization in relation to leaf senescence, grain yield and protein concentration in Indian wheat cultivars
© 2020 The Authors Nitrogen (N) fertilizer represents a significant cost for the grower and may also have environmental impacts through nitrate leaching and N2O (a greenhouse gas) emissions associated with denitrification. The objectives of this study were to quantify the genetic variability in N partitioning and N remobilization in Indian spring wheat cultivars and identify traits for improved grain yield and grain protein content for application in breeding N-efficient cultivars. Twenty-eight bread wheat cultivars and two durum wheat cultivars were tested in field experiments in two years in Maharashtra, India. Growth analysis was conducted at anthesis and harvest to assess above-ground dry matter (DM) and dry matter and N partitioning. Flag-leaf photosynthesis rate (Amax), flag-leaf senescence rate and canopy normalized difference vegetation index (NDVI) were also assessed. Significant N × genotype level interaction was observed for grain yield and N-use efficiency. There was a positive linear association between post-anthesis flag-leaf Amax and grain yield amongst the 30 genotypes under high N (HN) conditions. Flag-leaf Amax was positively associated with N uptake at anthesis (AGNA). Under both HN and low N (LN) conditions, higher N uptake at anthesis was associated with delayed onset of flag-leaf senescence and higher grain yield. Under N limitation, there was a genetic negative correlation between grain yield and grain protein concentration. Deviation from this negative relationship (grain protein deviation or GPD) was related to genotypic differences in post-anthesis N uptake. It is concluded that N uptake at anthesis was an important determinant of flag-leaf photosynthesis rate and grain yield under high N conditions; while post-anthesis N uptake was an important determinant of GPD of wheat grown under low to moderate N conditions in India
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