727 research outputs found
Economics of Krishik Bandhu Drip Irrigation: An Empirical Analysis
The impact of Krishik Bandhu (KB) drip irrigation has been reported on productivities, incomes and benefit-cost ratios of sugarcane, banana, chilli and cotton in 51 villages of Tamil Nadu, Maharashtra and Madhya Pradesh states. The crop productivities, incomes and benefit-cost ratios under drip irrigation method have been found far higher in all the crops and in all the selected regions of these three states compared to those under the conventional flood irrigation method. The KB drip irrigation technology has been found to be far superior than the flood irrigation method.Agricultural and Food Policy,
Hidden Order in Crackling Noise during Peeling of an Adhesive Tape
We address the long standing problem of recovering dynamical information from
noisy acoustic emission signals arising from peeling of an adhesive tape
subject to constant traction velocity. Using phase space reconstruction
procedure we demonstrate the deterministic chaotic dynamics by establishing the
existence of correlation dimension as also a positive Lyapunov exponent in a
mid range of traction velocities. The results are explained on the basis of the
model that also emphasizes the deterministic origin of acoustic emission by
clarifying its connection to sticks-slip dynamics.Comment: 5 pages, 10 figure
Implant isolation of Zn-doped GaAs epilayers: effects of ion species, doping concentration, and implantation temperature
The electrical isolation of Zn-doped GaAs layers grown by metalorganic chemical vapor deposition was studied using H, Li, C, and O ion implantation. The ion mass did not play a significant role in the stability of isolation, and a similar activation energy of ∼(0.63±0.03 eV) was obtained for isolation using either H or O ions. Furthermore, the isolation was stable against isochronal annealing up to 550 °C as long as the ion dose was 2–3.5 times the threshold dose for complete isolation, Dth, for the respective ion species. By studying the thermal stability and the temperature dependence of isolation, we have demonstrated the various stages leading to the production of stable isolation with the increasing dose of 2 MeV C ions. For ion doses less than 0.5Dth,point defects which are stable below 250 °C are responsible for the degradation of hole mobility and hole trapping. The stability of isolation is increased to ∼400 °C for a dose Dth due to the creation of defect pairs. Furthermore, the hopping conduction mechanism is already present in the damaged epilayer implanted to Dth. Higher order defect clusters or complexes, such as the arsenic antisite, AsGa, are responsible for the thermal stability of implantation isolation at 550 °C. The substrate temperature (−196–200 °C) does not have an effect on the isolation process further revealing that the stability of isolation is related to defect clusters and not point-like defects. An average number of eight carbon ions with energy of 2 MeV are required to compensate 100 holes, which provides a general guideline for choosing the ion dose required for the isolation of a GaAs layer doped with a known Zn concentration. A discussion of the results on the implantation isolation of p-GaAs previously reported in the literature is also included.P.N.K.D. acknowledges the Australian Research Council
for financial support
Propose a comparison method of the PV variability based on roof-top PV solar data of Australia
© 2018 International Journal of Renewable Energy Research. The use of renewable sources of energy is rising in Australia, and with solar energy becoming the most dominant; the solar (PV) roof-top plant penetration in the electrical energy distribution grid is increasing. As Australia is the sixth largest country in the world consisting of a diverse range of climates, this may be a concern to Distribution Service Operators (DSOs) as the variability in PV power output in different areas, climates/weather and even time of day. This means that DSOs are required to quantify these 'uncertainties' for different zones in Australia to aid in the energy planning. This paper will examine PV variability metrics to identify suitable PV variable metric based on purpose of application and propose a method to compare PV variability of large cities in Australia based on historical roof-top PV solar data. This proposed method examined variability metrics and find out suitable variability metric based on purpose of application. The comparative study shows that the PV variability and the amount of smoothing are not equal at all the distribution area in Australia and varies with geographical climatic scenario
Electro-optical switching by liquid-crystal controlled metasurfaces
We study the optical response of a metamaterial surface created by a lattice
of split-ring resonators covered with a nematic liquid crystal and demonstrate
millisecond timescale switching between electric and magnetic resonances of the
metasurface. This is achieved due to a high sensitivity of liquid-crystal
molecular reorientation to the symmetry of the metasurface as well as to the
presence of a bias electric field. Our experiments are complemented by
numerical simulations of the liquid-crystal reorientation.Comment: 6 pages, 3 figure
Comparative assessment of floristic structure, diversity and regeneration status of tropical rain forests of Western Ghats of Karnataka, India
Tropical forests are one of the richest landscapes in terms of its richness, diversity and endemicity. The present study was carried out in the Central Western Ghats: one of the hottest hotspot of biodiversity. The aim of the study was to compare floristic diversity in tropical wet evergreen forest between northern and southern parts of Western Ghats of Karnataka. Kodagu district in southern part and Uttara Kannada district in northern part was chosen to assess the same, as these two districts cover highest forest cover in the Western Ghats of Karnataka. In each district all the evergreen forests were sampled with 1000 m X 5 belt transacts. Totally 22 such samplings were done both southern and northern part of Western Ghats. In each of these transacts all the trees measuring e” 30 gbh were enumerated and botanically identified to the species level and the same was used for computation of diversity indices. The richness and diversity was comparatively higher in southern part compared to northern part of Western Ghats, where as the richness of threatened tree species was comparatively higher in northern part of Western Ghats. In addition to the species richness and diversity, the paper also deals with the dominant tree species and families in both the region
Evolution of InAs branches in InAs/GaAs nanowire heterostructures
Branched nanowireheterostructures of InAs∕GaAs were observed during Au-assisted growth of InAs on GaAsnanowires. The evolution of these branches has been determined through detailed electron microscopy characterization with the following sequence: (1) in the initial stage of InAsgrowth, the Au droplet is observed to slide down the side of the GaAsnanowire, (2) the downward movement of Aunanoparticle later terminates when the nanoparticle encounters InAsgrowing radially on the GaAsnanowire sidewalls, and (3) with further supply of In and As vapor reactants, the Aunanoparticles assist the formation of InAs branches with a well-defined orientation relationship with GaAs∕InAs core/shell stems. We anticipate that these observations advance the understanding of the kink formation in axial nanowireheterostructures.The Australian Research Council is acknowledged for
the financial support of this project. One of the authors
M.P. acknowledges the support of an International Postgraduate
Research Scholarship
Towards a better understanding of the operative mechanisms underlying impurity-free disordering of GaAs: Effect of stress
The effect of stress on defect creation and diffusion during impurity-free disordering of SiOₓ-capped n-GaAs epitaxial layers has been investigated using deep level transient spectroscopy. The oxygen content in the SiOₓ layer and the nature of the stress that it imposes on the GaAs layer were varied by changing the nitrous oxideflow rate, N, during plasma-enhanced chemical vapor deposition of the capping layer. The peak intensity of defects S1 and S4 increased with the increasing nitrous oxideflow rate to exhibit a maximum in the range 80 sccm350 sccm. On the other hand, the peak intensity of S2* increased linearly with N. We have explained the maximum in the intensity of defects S1 and S4 for 80 sccm<N<200 sccm to be due to a corresponding maximum in the compressive stress which is experienced by the capped GaAs layer during annealing. Although the creation of S2*, which we have proposed to be a complex involving the galliumvacancy(VGa), is enhanced with the increasing compressive stress, it also becomes efficiently converted into the arsenic-antisite, AsGa. The compound effect of these opposing mechanisms results in a linear dependence of the peak intensity of S2* on N. This study is to the best of our knowledge the first to provide the evidence for the stress-dependent anti-correlation between VGa- and AsGa-related defects in GaAs. We have also narrowed the origin of S1 to complexes involving arsenic interstitials, Asi, and/or AsGa.P. N. K. Deenapanray and H. H. Tan gratefully acknowledge
the financial support of the Australian Research
Council
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