6,475 research outputs found
Recommendation for consideration in the development of Nepal's Irrigation Master Plan. Part 1 - Management of irrigation systems for effective O & M and resource mobilization; Part 2 - Farmer managed irrigation systems. Occasional paper
Irrigation management / Farmer managed irrigation systems / Resource management / Agricultural production / Nepal
String Cosmology in Anisotropic Bianchi-II Space-time
The present study deals with a spatially homogeneous and anisotropic
Bianchi-II cosmological model representing massive strings. The energy-momentum
tensor, as formulated by Letelier (1983), has been used to construct a massive
string cosmological model for which the expansion scalar is proportional to one
of the components of shear tensor. The Einstein's field equations have been
solved by applying a variation law for generalized Hubble's parameter that
yields a constant value of deceleration parameter in Bianchi-II space-time. A
comparative study of accelerating and decelerating modes of the evolution of
universe has been carried out in the presence of string scenario. The study
reveals that massive strings dominate the early Universe. The strings
eventually disappear from the Universe for sufficiently large times, which is
in agreement with the current astronomical observations.Comment: 11 pages, 6 figures (To appear in Mod. Phys. Lett. A) In this
version, the cosmic string has been directed along z-direction and the
resultant field equations have been solved exactl
Sampling rare fluctuations of height in the Oslo ricepile model
We have studied large deviations of the height of the pile from its mean
value in the Oslo ricepile model. We sampled these very rare events with
probabilities of order by Monte Carlo simulations using importance
sampling. These simulations check our qualitative arguement [Phys. Rev. E, {\bf
73}, 021303, 2006] that in steady state of the Oslo ricepile model, the
probability of large negative height fluctuations about
the mean varies as as with
held fixed, and .Comment: 7 pages, 8 figure
Is 4U 0114+65 an eclipsing HMXB?
We present the pulsation and spectral characteristics of the HMXB 4U 0114+65
during a \emph{Suzaku} observation covering the part of the orbit that included
the previously known low intensity emission of the source (dip) and the egress
from this state. This dip has been interpreted in previous works as an X-ray
eclipse. Notably, in this Suzaku observation, the count rate during and outside
the dip vary by a factor of only 2-4 at odds with the eclipses of other HMXBs,
where the intensity drops upto two orders of magnitude. The orbital intensity
profile of 4U 0114+65 is characterized by a narrow dip in the RXTE-ASM (2-12
\rm{keV}) light curve and a shallower one in the Swift-BAT (15-50 \rm{keV}),
which is different from eclipse ingress/egress behaviour of other HMXBs. The
time-resolved spectral analysis reveal moderate absorption column density
(N - 2-20 atoms ) and a relatively low
equivalent width ( 30 \rm{eV} \& 12 \rm{eV} of the iron K and
K lines respectively) as opposed to the typical X-ray spectra of HMXBs
during eclipse where the equivalent width is 1 \rm{keV}. Both XIS and
PIN data show clear pulsations during the dip, which we have further confirmed
using the entire archival data of the IBIS/ISGRI and JEM-X instruments onboard
\emph{INTEGRAL}. The results we presented question the previous interpretation
of the dip in the light curve of 4U 0114+65 as an X-ray eclipse. We thus
discuss alternative interpretations of the periodic dip in the light curve of
4U 0114+65.Comment: 16 pages, 7 figures, 1 table, Accepted in MNRA
From farmers' fields to data fields and back: A Synthesis of Participatory Information Systems for Irrigation and other Resources: Proceedings of an International Workshop held at the Institute of Agriculture and Animal Science, Rampur, Nepal, 21-26 March 1993
Irrigation / Forestry / Natural resources / Farmer participation / Participatory rural appraisal / Rapid rural appraisal / GIS / Data collection / Databases / Field tests / Farmers' associations / Training / Water rights / Water law / Institutions / Non-governmental organizations / India / Nepal
X-ray line intensities for ions of the helium isoelectronic sequence in high temperature plasmas
Processing & Characterization of UHMWPE-CSP (Coconut Shell Powder) Composite
The stringent environmental considerations like deforestation have led to a thinking to replace wood with various synthetic materials, such as polymer composites. In
this paper, an attempt has been made to reinforce coconut shell. powders (CSP) in a ultrahigh molecular weight polyethylene (UHMWPE). Prepared by powder metallurgy
route, these composites have been evaluated for its mechanical properties and compared with pure UHMWPE (0 vol% CSP). With increasing addition of reinforcement,
the impact strength decreases marginally upto 20 vol% after which there is a sharp W. But the compressive strength has not decreased much even after 30 vol% of
CSP. An optimum loading of 20 vol% is found to be beneficial for better properties
Probability distribution of residence-times of grains in sandpile models
We show that the probability distribution of the residence-times of sand
grains in sandpile models, in the scaling limit, can be expressed in terms of
the survival probability of a single diffusing particle in a medium with
absorbing boundaries and space-dependent jump rates. The scaling function for
the probability distribution of residence times is non-universal, and depends
on the probability distribution according to which grains are added at
different sites. We determine this function exactly for the 1-dimensional
sandpile when grains are added randomly only at the ends. For sandpiles with
grains are added everywhere with equal probability, in any dimension and of
arbitrary shape, we prove that, in the scaling limit, the probability that the
residence time greater than t is exp(-t/M), where M is the average mass of the
pile in the steady state. We also study finite-size corrections to this
function.Comment: 8 pages, 5 figures, extra file delete
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