12,914 research outputs found
Does Microcredit Reach the Poor and Vulnerable? Evidence from Northern Bangldesh.
The Grameen Bank's success in Bangladesh has made microcredit the hot new idea for reducing poverty. This paper uses panel data from two Bangladeshi villages to test if loan recipients are poorer and more vulnerable than non-recipients. Poverty is measured by levels of consumption. Vulnerablitiy is measured as fluctuations in consumption (associated with inefficient risk sharing). We find that loan recipients are poorer than non-recipients in both villages, but are more vulnerable than non-recipients only in the richer and more diversified village. Though microcredit programs target the landless, there is substantial leakage to the landed. Landlessness is not significangly associated with either poverty or vulnerablitiy, but female headship is. Female headed households may be a more appropriate target group for anti-poverty credit programs.POVERTY ; RISK ; ECONOMIC GROWTH
Persistent currents in mesoscopic rings and boundary conformal field theory
A tight-binding model of electron dynamics in mesoscopic normal rings is
studied using boundary conformal field theory. The partition function is
calculated in the low energy limit and the persistent current generated as a
function of an external magnetic flux threading the ring is found. We study the
cases where there are defects and electron-electron interactions separately.
The same temperature scaling for the persistent current is found in each case,
and the functional form can be fitted, with a high degree of accuracy, to
experimental data.Comment: 6 pages, 4 enclosed postscript figure
Nonlocal mixing of supercurrents in Josephson ballistic point contact
We study coherent current states in the mesoscopic superconducting weak link
simultaneously subjected to the order parameter phase difference on the contact
and to the tangential to the junction interface superfluid velocity in the
banks. The Josephson current-phase relation controlled by the external
transport current is obtained. At phase difference close to pi the nonlocal
nature of the Josephson phase-dependent current results in the appearance of
two vortexlike states in the vicinity of the contact.Comment: 4 pages, 6 figures; to be published in Phys. Rev. B; e-mail:
[email protected]
Theory of pinning in a Superconducting Thin Film Pierced by a Ferromagnetic Columnar Defect
This is an analytical study of pinning and spontaneous vortex phase is a
system consisting of a superconducting thin film pierced by a long
ferromagnetic columnar defect of finite radius . The magnetic fields,
screening currents, energy and pinning forces for this system are calculated.
The interaction between the magnetic field of vortices and the magnetization
outside the plane of the film and its close proximity enhances vortex pinning
significantly. Spontaneous vortex phase appears when the magnetization of the
columnar defect is increased above a critical value. Transitions between phases
characterized by different number of flux quanta are also studied. These
results are generalized to the case when the superconductor is pierced by an
array of columnar defects.Comment: 6 pages, 4 figures, Accepted for publication in Phys. Rev.
Effect of point-contact transparency on coherent mixing of Josephson and transport supercurrents
The influence of electron reflection on dc Josephson effect in a ballistic
point contact with transport current in the banks is considered theoretically.
The effect of finite transparency on the vortex-like currents near the contact
and at the phase difference which has been predicted recently
\cite{KOSh}, is investigated. We show that at low temperatures even a small
reflection on the contact destroys the mentioned vortex-like current states,
which can be restored by increasing of the temperature.Comment: 6 pages, 8 Figures, Latex Fil
The survey of the effect of ginger extract on gastric residual volume in mechanically ventilated patients hospitalized in the Intensive Care Units
Background and purpose: Delayed gastric emptying in mechanically ventilated patients is common. According to evidences, Ginger can accelerate gastric emptying. This study aimed to determine the effect of ginger extract on gastric residual volume of patients admitted to the Intensive Care Unit. Materials and Methods: In this double-blind randomized controlled clinical trial with before and after schematization, 24 mechanically ventilated patients hospitalized in ICUs were divided into two groups, intervention group (12 patients) and control group (n = 12) after matching for sex and severity of disease. After 48 hours of feeding with a standard gavage solution, the intervention group received 120mg of ginger extract in 4 days and the control group received 5 ml water as placebo in 4 days. The mean residual volume was recorded in the fifth and the sixth days. Data analysis was done with independent and paired T-tests at a significance level of 0.05. Results: The mean residual volume in the first 48 hours was not significantly different between the groups. But after 48 hours of starting treatment, the average of mean and standard deviation of the residual volume in the fifth and sixth days were (24.58±16.81) in intervention group and (108.33±15.09) in control group that according to the Independent T-test showed a significant difference (P <0.0001). Discussion and Conclusion: The result of this study showed that ginger extract reduces gastric residual volume in mechanically ventilated patients hospitalized in intensive care units compared with placebo. © 2013 AENSI Publisher All rights reserved
Continuous Monitoring of Rabi Oscillations in a Josephson Flux Qubit
Under resonant irradiation, a quantum system can undergo coherent (Rabi)
oscillations in time. We report evidence for such oscillations in a
_continuously_ observed three-Josephson-junction flux qubit, coupled to a
high-quality tank circuit tuned to the Rabi frequency. In addition to
simplicity, this method of_Rabi spectroscopy_ enabled a long coherence time of
about 2.5 microseconds, corresponding to an effective qubit quality factor
\~7000.Comment: REVTeX4, 4pp., 4 EPS figure files. v3: changed title, fixed typos;
final, to appear in PR
Robust local and non-local transport in the Topological Kondo Insulator SmB in the presence of high magnetic field
SmB has been predicted to be a Kondo Topological Insulator with
topologically protected conducting surface states. We have studied
quantitatively the electrical transport through surface states in high quality
single crystals of SmB. We observe a large non-local surface signal at
temperatures lower than the bulk Kondo gap scale. Measurements and finite
element simulations allow us to distinguish unambiguously between the
contributions from different transport channels. In contrast to general
expectations, the electrical transport properties of the surface channels was
found to be insensitive to high magnetic fields. Local and non-local
magnetoresistance measurements allowed us to identify definite signatures of
helical spin states and strong inter-band scattering at the surface.Comment: 7 pages, 8 figures, 1 tabl
- …