21,216 research outputs found
Agricultural Cooperatives and Unions of Cooperatives in Bosnia and Herzegovina: Opportunities for Improvement
Given the breakup of Yugoslavia and the ensuing war, there has been massive changes in the agricultural structure in Bosnia and Herzegovina. In particular, the remade cooperatives and the unions of cooperatives that are supposed to serve them are struggling. This paper examines the needs of the agricultural cooperatives to be more successful and identifies what support will likely come from the unions of cooperatives and what must come from other sources. Data was obtained in three ways: 1) questionnaires to a large group of cooperatives, 2) focus groups with a smaller number of cooperatives, and 3) personal interviews with union of cooperatives representatives. The findings indicated that the unions of cooperatives are working on institutional issues such as registering and auditing cooperatives, and resolving land ownership conflicts. However, since the cooperatives are not familiar with the market economy, they also need help in business management, marketing, legal services, and organizational effectiveness. It is not likely that the unions will be able to help the cooperatives with these issues. New partners such as the Ministry of Agriculture, colleges of agriculture, or non-governmental organizations should be tasked with providing this educational support.Bosnia and Herzegovina, agricultural cooperatives, union of agricultural cooperatives, agricultural development, Agribusiness,
Lie algebraic noncommuting structures from reparametrisation symmetry
We extend our earlier work of revealing both space-space and space-time
noncommuting structures in various models in particle mechanics exhibiting
reparametrisation symmetry. We show explicitly (in contrast to the earlier
results in our paper \cite{sg}) that for some special choices of the
reparametrisation parameter , one can obtain space-space noncommuting
structures which are Lie-algebraic in form even in the case of the relativistic
free particle. The connection of these structures with the existing models in
the literature is also briefly discussed. Further, there exists some values of
for which the noncommutativity in the space-space sector can be made
to vanish. As a matter of internal consistency of our approach, we also study
the angular momentum algebra in details.Comment: 9 pages Latex, some references adde
The preparation of ultra fine beryllium powder by the amalgam process Technical report
Beryllium powder production by electrolysis of beryllium chloride-sodium chloride molten eutectic mixtur
Derivation of reduced two-dimensional fluid models via Dirac's theory of constrained Hamiltonian systems
We present a Hamiltonian derivation of a class of reduced plasma
two-dimensional fluid models, an example being the Charney-Hasegawa-Mima
equation. These models are obtained from the same parent Hamiltonian model,
which consists of the ion momentum equation coupled to the continuity equation,
by imposing dynamical constraints. It is shown that the Poisson bracket
associated with these reduced models is the Dirac bracket obtained from the
Poisson bracket of the parent model
Next-to-leading order Calculation of a Fragmentation Function in a Light-Cone Gauge
The short-distance coefficients for the color-octet ^3S_1 term in the
fragmentation function for a gluon to split into polarized heavy quarkonium
states are re-calculated to order alpha_s^2. The light-cone gauge remarkably
simplifies the calculation by eliminating many Feynman diagrams at the expense
of introducing spurious poles in loop integrals. We do not use any conventional
prescriptions for spurious pole. Instead, we only use gauge invariance with the
aid of Collins-Soper definition of the fragmentation function. Our result
agrees with a previous calculation of Braaten and Lee in the Feynman gauge, but
disagrees with another previous calculation.Comment: 16 pages, 4 figures, version published in Physical Review
A position sensitive phoswich hard X-ray detector system
A prototype position sensitive phoswich hard X-ray detector, designed for eventual astronomical usage, was tested in the laboratory. The scintillation crystal geometry was designed on the basis of a Monte Carlo simulation of the internal optics and includes a 3mm thick NaI(T1) primary X-ray detector which is actively shielded by a 20 mm thick CsI(T1) scintillation crystal. This phoswich arrangement is viewed by a number two inch photomultipliers. Measured values of the positional and spectral resolution of incident X-ray photons are compared with calculation
Two-stage Kondo effect in a four-electron artificial atom
An artificial atom with four electrons is driven through a singlet-triplet
transition by varying the confining potential. In the triplet, a Kondo peak
with a narrow dip at drain-source voltage V_ds=0 is observed. The low energy
scale V_ds* characterizing the dip is consistent with predictions for the
two-stage Kondo effect. The phenomenon is studied as a function of temperature
T and magnetic field B, parallel to the two-dimensional electron gas. The low
energy scales T* and B* are extracted from the behavior of the zero-bias
conductance and are compared to the low energy scale V_ds* obtained from the
differential conductance. Good agreement is found between kT* and |g|muB*, but
eV_ds* is larger, perhaps because of nonequilibrium effects.Comment: 7 pages, 7 figures. Added labels on Fig. 3f and one referenc
Polarization and readout of coupled single spins in diamond
We study the coupling of a single nitrogen-vacancy center in diamond to a
nearby single nitrogen defect at room temperature. The magnetic dipolar
coupling leads to a splitting in the electron spin resonance frequency of the
nitrogen-vacancy center, allowing readout of the state of a single nitrogen
electron spin. At magnetic fields where the spin splitting of the two centers
is the same we observe a strong polarization of the nitrogen electron spin. The
amount of polarization can be controlled by the optical excitation power. We
combine the polarization and the readout in time-resolved pump-probe
measurements to determine the spin relaxation time of a single nitrogen
electron spin. Finally, we discuss indications for hyperfine-induced
polarization of the nitrogen nuclear spin
The hydrology of prehistoric farming systems in a central Arizona ecotone
The prehistoric land use and water management in the semi-arid Southwest was examined. Remote sensing data, geology, hydrology and biology are discussed along with an evaluation of remote sensing contributions, recommendations for applications, and proposed future remote sensing studies
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