9,706 research outputs found
Community at the Core: A Study of Sarvodaya Nano Finance Limited
The paper traces the evolution of Sarvodaya Nano Finance Limited (SNFL). At the outset we explore the background of SNFL, the motivation for the promoters to set up the organisation and how it has grown from the time it was taken over by the community trusts promoted by ASSEFA. As a part of the study, we examine the unique legal structure set up for federating the small SHGs that were widely spread out in the areas of its operation. The idea of federating the SHGs was to leverage the dispersed savings and interest earned on the initial donor resources that were made available to the SHGs at their early stages. The aggregation of these dispersed resources into SNFL enables the women SHGs to mobilise funds from commercial banks and specialised MFI lenders, for an accelerated growth of the movement. The paper examines the rationale for having this structure, its vulnerabilities and the possibilities for growth within the given structure. We argue that this is not a structure that can be replicated easily. We also argue that it cannot grow aggressively in the long run, unless some basic design changes are made. The paper also discusses the basic question on how to structure resources that are given by the donor community for the larger benefit of the poor; and when to bring in the individual stakes of the beneficiaries if one were to promote long lasting institutions. The paper also raises critical questions on governance and management. While appreciating the impressive result achieved by ASSEFA and BASIX in getting a community owned professionally managed institution into being, it also raises questions on whether there are inbuilt mechanisms of carrying forward this effectively in future – given the structuring of capital and rights of each of the constituents.
Effects on Amorphous Silicon Photovoltaic Performance from High-temperature Annealing Pulses in Photovoltaic Thermal Hybrid Devices
There is a renewed interest in photovoltaic solar thermal (PVT) hybrid
systems, which harvest solar energy for heat and electricity. Typically, a main
focus of a PVT system is to cool the photovoltaic (PV) cells to improve the
electrical performance, however, this causes the thermal component to
under-perform compared to a solar thermal collector. The low temperature
coefficients of amorphous silicon (a-Si:H) allow for the PV cells to be
operated at higher temperatures and are a potential candidate for a more
symbiotic PVT system. The fundamental challenge of a-Si:H PV is light-induced
degradation known as the Staebler-Wronski effect (SWE). Fortunately, SWE is
reversible and the a-Si:H PV efficiency can be returned to its initial state if
the cell is annealed. Thus an opportunity exists to deposit a-Si:H directly on
the solar thermal absorber plate where the cells could reach the high
temperatures required for annealing.
In this study, this opportunity is explored experimentally. First a-Si:H PV
cells were annealed for 1 hour at 100\degreeC on a 12 hour cycle and for the
remaining time the cells were degraded at 50\degreeC in order to simulate
stagnation of a PVT system for 1 hour once a day. It was found that, when
comparing the cells after stabilization at normal 50\degreeC degradation, this
annealing sequence resulted in a 10.6% energy gain when compared to a cell that
was only degraded at 50\degreeC
Dynamics of interacting quintessence
In this paper, we investigate coupled quintessence with scaling potential
assuming specific forms of the coupling as namely, ,
and , and
present phase space analysis for three different interacting models. We focus
on the attractor solutions that can give rise to late time acceleration with
of order unity in order to alleviate the coincidence
problem.Comment: 11 pages, 3 figures, matches with the published versio
Resisting antimicrobial resistance: lessons from fungus farming ants
Attine ants use antimicrobials produced by commensal bacteria to inhibit parasites on their fungal gardens. However, in this agricultural system, antimicrobial use does not lead to overwhelming resistance, as is typical in clinical settings. Mixtures of continually evolving antimicrobial variants could support these dynamics. [Abstract copyright: Copyright © 2019 Elsevier Ltd. All rights reserved.
Dynamics of coupled phantom and tachyon fields
In this paper, we apply the dynamical analysis to a coupled phantom field
with scaling potential taking particular forms of the coupling (linear and
combination of linear), and present phase space analysis. We investigate if
there exist late time accelerated scaling attractor that has the ratio of dark
energy and dark matter densities of the order one. We observe that the
scrutinized couplings cannot alleviate the coincidence problem, however acquire
stable late time accelerated solutions. We also discuss coupled tachyon field
with inverse square potential assuming linear coupling.Comment: 16 pages, 6 caption figures, 3 Tables, text, figure are added,
matches with the published versio
DC field induced enhancement and inhibition of spontaneous emission in a cavity
We demonstrate how spontaneous emission in a cavity can be controlled by the
application of a dc field. The method is specially suitable for Rydberg atoms.
We present a simple argument for the control of emission.Comment: 3-pages, 2figure. accepted in Phys. Rev.
Enhanced grain surface effect on magnetic properties of nanometric La0.7Ca0.3MnO3 manganite : Evidence of surface spin freezing of manganite nanoparticles
We have investigated the effect of nanometric grain size on magnetic
properties of single phase, nanocrystalline, granular La0.7Ca0.3MnO3 (LCMO)
sample. We have considered core-shell structure of our LCMO nanoparticles,
which can explain its magnetic properties. From the temperature dependence of
field cooled (FC) and zero-field cooled (ZFC) dc magnetization (DCM), the
magnetic properties could be distinguished into two regimes: a relatively high
temperature regime T > 40 K where the broad maximum of ZFC curve (at T = Tmax)
is associated with the blocking of core particle moments, whereas the sharp
maximum (at T = TS) is related to the freezing of surface (shell) spins. The
unusual shape of M (H) loop at T = 1.5 K, temperature dependent feature of
coercive field and remanent magnetization give a strong support of surface spin
freezing that are occurring at lower temperature regime (T < 40 K) in this LCMO
nanoparticles. Additionally, waiting time (tw) dependence of ZFC relaxation
measurements at T = 50 K show weak dependence of relaxation rate [S(t)] on tw
and dM/dln(t) following a logarithmic variation on time. Both of these features
strongly support the high temperature regime to be associated with the blocking
of core moments. At T = 20 K, ZFC relaxation measurements indicates the
existence of two different types of relaxation processes in the sample with
S(t) attaining a maximum at the elapsed time very close to the wait time tw =
1000 sec, which is an unequivocal sign of glassy behavior. This age-dependent
effect convincingly establish the surface spin freezing of our LCMO
nanoparticles associated with a background of superparamagnetic (SPM) phase of
core moments.Comment: 41 pages, 10 figure
Indications of superconductivity in doped highly oriented pyrolytic graphite
We have observed possible superconductivity using standard resistance vs.
temperature techniques in phosphorous ion implanted Highly Oriented Pyrolytic
Graphite. The onset appears to be above 100 K and quenching by an applied
magnetic field has been observed. The four initial boron implanted samples
showed no signs of becoming superconductive whereas all four initial and eight
subsequent samples that were implanted with phosphorous showed at least some
sign of the existence of small amounts of the possibly superconducting phases.
The observed onset temperature is dependent on both the number of electron
donors present and the amount of damage done to the graphene sub-layers in the
Highly Oriented Pyrolytic Graphite samples. As a result the data appears to
suggest that the potential for far higher onset temperatures in un-damaged
doped graphite exists.Comment: 7 pages, 1 table, 5 figures, 11 references, Acknowledgments section
was correcte
Generation of a superposition of multiple mesoscopic states of radiation in a resonant cavity
Using resonant interaction between atoms and the field in a high quality
cavity, we show how to generate a superposition of many mesoscopic states of
the field. We study the quasi-probability distributions and demonstrate the
nonclassicality of the superposition in terms of the zeroes of the Q-function
as well as the negativity of the Wigner function. We discuss the decoherence of
the generated superposition state. We propose homodyne techniques of the type
developed by Auffeves et al [Phys. Rev. Lett. 91, 230405 (2003)] to monitor the
superposition of many mesoscopic states.Comment: submitted to Phys. Rev.
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