3,167 research outputs found
Indirect observation of unobservable interstellar molecules
It is suggested that the abundances of neutral non-polar interstellar molecules unobservable by radio astronomy can be systematically determined by radio observation of the protonated ions. As an example, observed N2H(+) column densities are analyzed to infer molecular nitrogen abundances in dense interstellar clouds. The chemistries and expected densities of the protonated ions of O2, C2, CO2, C2H2 and CH4 are then discussed. Microwave transition frequencies fo HCO2(+) and C2H3(+) are estimated, and a preliminary astronomical search for HCO2(+) is described
Financial Impacts of Regional Differences in Dairies
The sensitivity of net cash farm income to changes in selected production variables, output prices, and input costs varies significantly across representative U.S. dairies. Different regions of the country were impacted differently by changes to production and prices.Agricultural Finance, Q12, Q14,
A Variational Approach to the Spinless Relativistic Coulomb Problem
By application of a straightforward variational procedure we derive a simple,
analytic upper bound on the ground-state energy eigenvalue of a
semirelativistic Hamiltonian for (one or two) spinless particles which
experience some Coulomb-type interaction.Comment: 7 pages, HEPHY-PUB 606/9
Regional and Structural Impacts of Alternative Dairy Policy Options
Milk and dairy product prices have fallen to their lowest levels in 3 years following the record highs of 2004 and 2005. The large government stockpiles of non-fat dry milk are gone, but threaten to build again as non-fat dry milk and cheese prices decline nearer the support price level. A new farm bill is scheduled to be written in 2007. The Milk Income Loss Contract (MILC) program included in the last farm bill was only authorized through September 2005. Subsequent legislation reinstated the MILC program through August 2007. WTO negotiations are on-going and could influence U.S. farm programs 1/. Dairy’s role in the U.S. amber box limit of 4.2 billion toward the annual amber box limit, but actual spending only averages about 400 million in amber box payments per year. The analysis uses representative dairy farms in major milk producing regions of the country developed by the AFPC for policy analysis.Agribusiness, Agricultural and Food Policy, Livestock Production/Industries,
The Effectiveness of Dairy Risk Management at Managing Income, Revenue, and Margin Risk
With the 2009 milk prices still fresh on everyone’s mind, there has been increased interest in ways to limit milk price volatility. Using SERF, this paper determined some dairies are willing to pay for limited milk price volatility and found a value they are willing to pay using risk premiums.Dairy, Stochastic Simulation, price volatility, Agricultural and Food Policy, Farm Management,
Classical and Quantum-Mechanical Calculations of HCO^+ + e → CO(v) + H
It has been suggested that interstellar CO produced in the dissociative recombination between HCO+ and electrons can be detected via infrared emission from excited vibrational levels. Using classical and quantum mechanical equations of motion, we have calculated the distribution of CO product vibrational states for the dissociative recombination reaction between HCO+ and electrons. We have assumed the dissociation to occur along a purely linear geometry. The CO vibrational distribution has been calculated for two electronic states: (1) the ground X1Σ^+ state and (2) the excited a ^3Π state. For the X state, we have used a newly calculated ab initio potential surface for the dissociation of HCO. Results for the a state can be compared with the results of experimental work by Adams and collaborators. Our results show that in general vibrational excitation of the CO product is not large, so that detection of infrared emission from interstellar clouds will not be facile
What a Difference a Year Makes in the Dairy Industry
The projections for feed and milk prices have changed over the last year. This study looks at how the changes affect the dairy industry. The high feed prices have been trumped by higher milk prices and the economic viability of the dairy industry has improved across the board.Demand and Price Analysis, Industrial Organization,
Profiles of Strong Permitted Lines in Classical T Tauri Stars
We present a spectral analysis of 30 T Tauri stars observed with the Hamilton
echelle spectrograph over more than a decade. One goal is to test
magnetospheric accretion model predictions. Observational evidence previously
published supporting the model, such as emission line asymmetry and a high
frequency of redshifted absorption components, are considered. We also discuss
the relation between different line forming regions and search for good
accretion rate indicators.
In this work we confirm several important points of the models, such as the
correlation between accretion and outflow, broad emission components that are
mostly central or slightly blueshifted and only the occasional presence of
redshifted absorption. We also show, however, that the broad emission
components supposedly formed in the magnetospheric accretion flow only
partially support the models. Unlike the predictions, they are sometimes
redshifted, and are mostly found to be symmetric. The published theoretical
profiles do not have a strong resemblance to our observed ones. We emphasize
the need for accretion models to include a strong turbulent component before
their profiles will match the observations. The effects of rotation, and the
outflow components, will also be needed to complete the picture.Comment: 25 pages including 9 figures, 3 tables, accepted for publication in
the Astronomical Journa
Radiative corrections to the pressure and the one-loop polarization tensor of massless modes in SU(2) Yang-Mills thermodynamics
We compute the one-loop polarization tensor for the on-shell, massless
mode in a thermalized SU(2) Yang-Mills theory being in its deconfining phase.
Postulating that SU(2), we discuss
's effect on the low-momentum part of the black-body spectrum at
temperatures where K.
A table-top experiment is proposed to test the above postulate. As an
application, we point out a possible connection with the stability of dilute,
cold, and old innergalactic atomic hydrogen clouds. We also compute the
two-loop correction to the pressure arising from the instantaneous massless
mode in unitary-Coulomb gauge, which formerly was neglected, and present
improved estimates for subdominant corrections.Comment: 25 pages, 17 figs, v4: consequences of a modification of the
evolution equation for the effectice coupling implemented, no qualitative
change of the physic
The Effects of Sex-Sorted Semen on Southern Dairy Farms
This paper examines the impact of sex-sorted semen adoption on dairy farm level economics. Representative dairies are used to simulate the financial impacts of moving to this new technology. Key economic, financial and herd dynamics will be compared among dairies to show how the uses of sex-sorted semen will affect dairy farms. All seven of the representative dairies that were analyzed sold surplus replacement heifers using sex-sorted semen. The increase use of sex-sorted semen can have very positive impacts on dairies throughout the Southern United States.Dairy production, sex sorted semen, production economics, scenario analysis, Agribusiness, Farm Management, Livestock Production/Industries, Production Economics,
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