2,548 research outputs found
Energy poverty in rural and urban India : are the energy poor also income poor ?
Energy poverty is a frequently used term among energy specialists, but unfortunately the concept is rather loosely defined. Several existing approaches measure energy poverty by defining an energy poverty line as the minimum quantity of physical energy neededto perform such basic tasks as cooking and lighting. This paper proposes an alternative measure that is based on energy demand. The energy poverty line is defined as the threshold point at which energy consumption begins to rise with increases in household income. This approach was applied to cross-sectional data from a comprehensive 2005 household survey representative of both urban and rural India. The findings suggest that in rural areas some 57 percent of households are energy poor, versus 22 percent that are income poor. For urban areas the energy poverty rate is 28 percent compared with 20 percent that are income poor. Policies to reduce energy poverty would include support for rural electrification, the promotion of more modern cooking fuels, and encouraging greater adoption of improved biomass stoves. A combination of these programs would play a significant role in reducing energy poverty in rural India.Energy Production and Transportation,Rural Poverty Reduction,Energy and Environment,Environment and Energy Efficiency,Energy Demand
Welfare impacts of rural electrification : a case study from Bangladesh
Lack of access to electricity is one of the major impediments to growth and development of the rural economies in developing countries. That is why access to modern energy, in particular to electricity, has been one of the priority themes of the World Bank and other development organizations. Using a cross-sectional survey conducted in 2005 of some 20,000 households in rural Bangladesh, this paper studies the welfare impacts of households'grid connectivity. Based on rigorous econometric estimation techniques, this study finds that grid electrification has significant positive impacts on households'income, expenditure, and educational outcomes. For example, the gain in total income due to electrification can be as much as 30 percent and as low as 9 percent. Benefits go up steadily as household exposure to grid electrification (measured by duration) increases and eventually reach a plateau. This paper also finds that rich households benefit more from electrification than poor households. Finally, estimates also show that income benefits of electrification on an average exceed cost by a wide margin.Energy Production and Transportation,Access to Finance,Engineering,Electric Power,Rural Poverty Reduction
Welfare impacts of rural electrification : evidence from Vietnam
Access to electricity is crucial for economic development and there is a growing body of literature on the impact of rural electrification on development. However, most studies have so far relied on cross-sectional surveys comparing households with and without electricity, which have well known causal attribution problems. This paper is one of the first studies to examine the welfare impacts of householdsâ rural electrification based on panel surveys conducted in 2002 and 2005 for some 1,100 households in rural Vietnam,. The findings indicate that grid electrification has been both extensive (connecting all surveyed communes by 2005) and intensive (connecting almost 80 percent of the surveyed households by 2005). Vietnam is unusual in that once electricity is locally available, both rich and poor households are equally likely to get the connection. The econometric estimations suggest that grid electrification has significant positive impacts on householdsâ cash income, expenditure, and educational outcomes. The benefits, however, reach a saturation point after prolonged exposure to electricity. Finally, this study recommends investigating the long-term benefits of rural electrification - not just for households, but for the rural economy as a whole.Energy Production and Transportation,Electric Power,Engineering,Access to Finance,Rural Poverty Reduction
Nurses\u27 and Patients\u27 Appraisals Show Patient Safety in Hospitals Remains a Concern
In the report To Err is Human (1999), the National Academy of Medicine called for national action to improve patient safety in hospitals. The report concluded that improving nurse work environmentsâassuring adequate nurse staffing and supporting nursesâ ability to care for patientsâwas critical to these efforts. Two decades later, have nurse work environments improved, and has that had a noticeable impact on patient safety? To find out, a research team led by LDI Senior Fellow Linda Aiken, PhD, RN surveyed more than 800,000 patients and 53,000 nurses in 535 hospitals in 2005, and again in 2016
Spin dynamics of SrCuO and the Heisenberg ladder
The Heisenberg antiferromagnet in the ladder geometry is studied as a
model for the spin degrees of freedom of SrCuO. The susceptibility and
the spin echo decay rate are calculated using a quantum Monte Carlo technique,
and the spin-lattice relaxation rate is obtained by maximum entropy analytic
continuation of imaginary time correlation functions. All calculated quantities
are in reasonable agreement with experimental results for SrCuO if the
exchange coupling K, i.e. significantly smaller than in
high-T cuprates.Comment: 11 pages (Revtex) + 3 uuencoded ps files. To appear in Phys. Rev. B,
Rapid Com
Rotation of planet-harbouring stars
The rotation rate of a star has important implications for the detectability,
characterisation and stability of any planets that may be orbiting it. This
chapter gives a brief overview of stellar rotation before describing the
methods used to measure the rotation periods of planet host stars, the factors
affecting the evolution of a star's rotation rate, stellar age estimates based
on rotation, and an overview of the observed trends in the rotation properties
of stars with planets.Comment: 16 pages, 4 figures: Invited review to appear in 'Handbook of
Exoplanets', Springer Reference Works, edited by Hans J. Deeg and Juan
Antonio Belmont
Transit Timing Observations from Kepler: VII. Confirmation of 27 planets in 13 multiplanet systems via Transit Timing Variations and orbital stability
We confirm 27 planets in 13 planetary systems by showing the existence of
statistically significant anti-correlated transit timing variations (TTVs),
which demonstrates that the planet candidates are in the same system, and
long-term dynamical stability, which places limits on the masses of the
candidates---showing that they are planetary. %This overall method of planet
confirmation was first applied to \kepler systems 23 through 32. All of these
newly confirmed planetary systems have orbital periods that place them near
first-order mean motion resonances (MMRs), including 6 systems near the 2:1
MMR, 5 near 3:2, and one each near 4:3, 5:4, and 6:5. In addition, several
unconfirmed planet candidates exist in some systems (that cannot be confirmed
with this method at this time). A few of these candidates would also be near
first order MMRs with either the confirmed planets or with other candidates.
One system of particular interest, Kepler-56 (KOI-1241), is a pair of planets
orbiting a 12th magnitude, giant star with radius over three times that of the
Sun and effective temperature of 4900 K---among the largest stars known to host
a transiting exoplanetary system.Comment: 12 pages, 13 figures, 5 tables. Submitted to MNRA
Kinematic properties of early-type galaxy haloes using planetary nebulae
We present new planetary nebulae (PNe) positions, radial velocities, and
magnitudes for 6 early-type galaxies obtained with the Planetary Nebulae
Spectrograph, their two-dimensional velocity and velocity dispersion fields. We
extend this study to include an additional 10 early-type galaxies with PNe
radial velocity measurements available from the literature, to obtain a broader
description of the outer-halo kinematics in early-type galaxies. These data
extend the information derived from stellar kinematics to typically up to ~8
Re. The combination of photometry, stellar and PNe kinematics shows: i) good
agreement between the PNe number density and the stellar surface brightness in
the region where the two data sets overlap; ii) good agreement between PNe and
stellar kinematics; iii) that the mean rms velocity profiles fall into two
groups: with of the galaxies characterized by slowly decreasing profiles and
the remainder having steeply falling profiles; iv) a larger variety of velocity
dispersion profiles; v) that twists and misalignments in the velocity fields
are more frequent at large radii, including some fast rotators; vi) that outer
haloes are characterised by more complex radial profiles of the specific
angular momentum-related lambda_R parameter than observed within 1Re; vii) that
many objects are more rotationally dominated at large radii than in their
central parts; and viii) that the halo kinematics are correlated with other
galaxy properties, such as total luminosity, isophotal shape, total stellar
mass, V/sigma, and alpha parameter, with a clear separation between fast and
slow rotators.Comment: 36 pages, 21 figures, revised version for MNRA
Dark Stars and Boosted Dark Matter Annihilation Rates
Dark Stars (DS) may constitute the first phase of stellar evolution, powered
by dark matter (DM) annihilation. We will investigate here the properties of DS
assuming the DM particle has the required properties to explain the excess
positron and elec- tron signals in the cosmic rays detected by the PAMELA and
FERMI satellites. Any possible DM interpretation of these signals requires
exotic DM candidates, with an- nihilation cross sections a few orders of
magnitude higher than the canonical value required for correct thermal relic
abundance for Weakly Interacting Dark Matter can- didates; additionally in most
models the annihilation must be preferentially to lep- tons. Secondly, we study
the dependence of DS properties on the concentration pa- rameter of the initial
DM density profile of the halos where the first stars are formed. We restrict
our study to the DM in the star due to simple (vs. extended) adiabatic
contraction and minimal (vs. extended) capture; this simple study is sufficient
to illustrate dependence on the cross section and concentration parameter. Our
basic results are that the final stellar properties, once the star enters the
main sequence, are always roughly the same, regardless of the value of boosted
annihilation or concentration parameter in the range between c=2 and c=5:
stellar mass ~ 1000M\odot, luminosity ~ 10^7 L\odot, lifetime ~ 10^6 yrs (for
the minimal DM models considered here; additional DM would lead to more massive
dark stars). However, the lifetime, final mass, and final luminosity of the DS
show some dependence on boost factor and concentration parameter as discussed
in the paper.Comment: 37 pages, 11 figure
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