15,113 research outputs found
USDA's Livestock Gross Margin Insurance for Dairy: What Is It and How Can It Be Used for Risk Management
Dairy farmers are faced with tremendous and increasing volatility, both in terms of milk prices, and the costs of purchased feed. There is a new weapon in the risk management arsenal of U.S. dairy producers: the Livestock Gross Margin for Dairy (LGM-Dairy) insurance program controls for lower gross revenue, defined as the value of milk produced minus feed costs. This program is administered by USDA's Risk Management Agency, and made available via authorized crop insurance agents to dairy farm operators in the lower 48 states.
Ferromagnetism in Fe-doped Ba6Ge25 Chiral Clathrate
We have successfully synthesized a Ba6Ge25 clathrate, substituting 3 Fe per
formula unit by Ge. This chiral clathrate has Ge sites forming a framework of
closed cages and helical tunnel networks. Fe atoms randomly occupy these sites,
and exhibit high-spin magnetic moments. A ferromagnetic transition is observed
with Tc = 170 K, the highest observed Tc for a magnetic clathrate. However, the
magnetic phase is significantly disordered, and exhibits a transformation to a
re-entrant spin glass phase. This system has a number of features in common
with other dilute magnetic semiconductors.Comment: Submitted to Applied Physics Letters. Fig. 1 resolution reduced for
online archive versio
Livestock Gross Margin Insurance for Dairy Cattle: An Analysis of Program Performance and Cost under Alternative Policy Configurations
Livestock Gross Margin insurance for dairy cattle (LGM-Dairy) is a risk management tool that can be used to insure a lower bound on a dairy producerâs gross margin. In this paper we (1) review the basic structure of LGM-Dairy (2) examine the sensitivity of Gross Margin Guarantee (GMG) and premium to changes in feeding regimes and (3) quantify impacts of changes in deductible level on important program characteristics.Dairy Price Risk, Uncertainty, Livestock Insurance., Agribusiness, Farm Management, Financial Economics, Livestock Production/Industries, Production Economics, Risk and Uncertainty,
Evaluation of flexible barrier and sabo dam to control effects of debris flow in Santo Domingo Ravine
Coast of Peru is characterized for the presence of ephemeral creeks which drain water only on wet season. The extremely dry soil and pebble combined with precipitation produce debris flow in a seasonal geodynamic. This is the case of Santo Domingo ravine which is located at eastern Lima, and drains their water to Rimac River. In this article the vulnerability of villages near to Santo Domingo ravine by debris flow and use of flexible barrier and sabo dams are analyzed. In a first stage, the liquid hydrograph to a 100 years return period was built and a solid hydrograph, a relationship between volume concentration and time, was essayed. Then, both the liquid and the solid hydrograph are calibrated in a debris flow numerical model and the vulnerability map is built. Finally, this model is coupled to the Rimac River to analyze the possible damming effect. Calibration of numerical model was done in base to previous estimated volumes by Japanese International Cooperation Agency (JICA). These first results permit to define high vulnerability zones which will be a reference to evaluate efficiency of control measures. In a second stage, mitigation effects of flexible barriers application is simulated in base to Debris Flow Barrier from GeobruggÂź. Also, application of sabo dams was evaluated to by using âKanakoâ debris flow simulator from Laboratory of Erosion Control, Division of Forest Science, Graduate School of Agriculture, Kyoto University, & SABO Technical Center. Results permit to evaluate efficiency and select the more economical option
Overcoming the su(2^n) sufficient condition for the coherent control of n-qubit systems
We study quantum systems with even numbers N of levels that are completely
state-controlled by unitary transformations generated by Lie algebras
isomorphic to sp(N) of dimension N(N+1)/2. These Lie algebras are smaller than
the respective su(N) with dimension N^2-1. We show that this reduction
constrains the Hamiltonian to have symmetric energy levels. An example of such
a system is an n-qubit system. Using a geometric representation for the quantum
wave function of a finite system, we present an explicit example that shows a
two-qubit system can be controlled by the elements of the Lie algebra sp(4)
(isomorphic to spin(5) and so(5)) with dimension ten rather than su(4) with
dimension fifteen. These results enable one to envision more efficient
algorithms for the design of fields for quantum-state engineering, and they
provide more insight into the fundamental structure of quantum control.Comment: 13 pp., 2 figure
The power of low-resolution spectroscopy: On the spectral classification of planet candidates in the ground-based CoRoT follow-up
Planetary transits detected by the CoRoT mission can be mimicked by a
low-mass star in orbit around a giant star. Spectral classification helps to
identify the giant stars and also early-type stars which are often excluded
from further follow-up.
We study the potential and the limitations of low-resolution spectroscopy to
improve the photometric spectral types of CoRoT candidates. In particular, we
want to study the influence of the signal-to-noise ratio (SNR) of the target
spectrum in a quantitative way. We built an own template library and
investigate whether a template library from the literature is able to reproduce
the classifications. Including previous photometric estimates, we show how the
additional spectroscopic information improves the constraints on spectral type.
Low-resolution spectroscopy (1000) of 42 CoRoT targets covering a
wide range in SNR (1-437) and of 149 templates was obtained in 2012-2013 with
the Nasmyth spectrograph at the Tautenburg 2m telescope. Spectral types have
been derived automatically by comparing with the observed template spectra. The
classification has been repeated with the external CFLIB library.
The spectral class obtained with the external library agrees within a few
sub-classes when the target spectrum has a SNR of about 100 at least. While the
photometric spectral type can deviate by an entire spectral class, the
photometric luminosity classification is as close as a spectroscopic
classification with the external library. A low SNR of the target spectrum
limits the attainable accuracy of classification more strongly than the use of
external templates or photometry. Furthermore we found that low-resolution
reconnaissance spectroscopy ensures that good planet candidates are kept that
would otherwise be discarded based on photometric spectral type alone.Comment: accepted for publication in Astronomische Nachrichten; 12 pages, 4
figures, 7 table
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