8,375 research outputs found
MARVEL analysis of the measured high-resolution rovibronic spectra of the calcium monohydroxide radical (CaOH)
The calcium monohydroxide radical (CaOH) is an important astrophysical
molecule relevant to cool stars and rocky exoplanets, amongst other
astronomical environments. Here, we present a consistent set of highly accurate
rovibronic (rotation-vibration-electronic) energy levels for the five lowest
electronic states (\tilde{X}\,^2\Sigma^+, \tilde{A}\,^2\Pi,
\tilde{B}\,^2\Sigma^+, \tilde{C}\,^2\Delta, \tilde{D}\,^2\Sigma^+) of
CaOH. A comprehensive analysis of the published spectroscopic literature on
this system has allowed 1955 energy levels to be determined from 3204
rovibronic experimental transitions, all with unique quantum number labelling
and measurement uncertainties. The dataset covers rotational excitation up to
for molecular states below 29\,000~cm. The analysis was
performed using the MARVEL algorithm, which is a robust procedure based on the
theory of spectroscopic networks. The dataset provided will significantly aid
future interstellar, circumstellar and atmospheric detections of CaOH, as well
as assisting in the design of efficient laser cooling schemes in ultracold
molecule research and precision tests of fundamental physics
Accurate Prediction of the Ammonia Probes of a Variable Proton-to-Electron Mass Ratio
A comprehensive study of the mass sensitivity of the
vibration-rotation-inversion transitions of NH, NH,
ND, and ND is carried out variationally using the TROVE
approach. Variational calculations are robust and accurate, offering a new way
to compute sensitivity coefficients. Particular attention is paid to the
transitions between the accidentally coinciding
rotation-inversion energy levels of the and states,
and the inversion transitions in the state affected by the "giant"
-type doubling effect. These transitions exhibit highly anomalous
sensitivities, thus appearing as promising probes of a possible cosmological
variation of the proton-to-electron mass ratio . Moreover, a simultaneous
comparison of the calculated sensitivities reveals a sizeable isotopic
dependence which could aid an exclusive ammonia detection.Comment: 18 pages, 2 figures, 10 table
Acer saccharinum L.
https://thekeep.eiu.edu/herbarium_specimens_byname/11945/thumbnail.jp
Estimating Alfalfa Quality in the Field
Knowledge of alfalfa nutritive value is essential for making informed forage management decisions in alfalfa-based livestock production systems. However, most harvest management and storage decisions are made with no chemical composition information because obtaining analytical data is time consuming and expensive. The quality of forage needed for a particular operation is influenced by the intended use of the forage and by the dietary requirements of a given class of livestock. The detergent fiber system of forage analysis (neutral detergent fiber, NDF; and acid detergent fiber, ADF) coupled with a measure of crude protein (CP) provide vital information for balancing rations of lactating dairy cows (Van Soest, 1994; Mertens, 1983). Therefore, knowledge of the preharvest concentration of NDF, ADF, and CP in alfalfa would allow producers to harvest, store, and inventory this feed resource based on its potential value in a ration
The Price Premium for Organic Babyfood: A Hedonic Analysis
The price premium associated with organic babyfood is estimated by applying a hedonic model to price and characteristic data for babyfood products collected in two cities: Raleigh, North Carolina, and San Jose, California. The price per ounce of babyfood is modeled as a function of a number of babyfood and store characteristics. The estimated organic price premium is generally equal to 3 cents to 4 cents per ounce. To the extent this premium reflects consumer willingness to pay to reduce pesticide exposures, it could be used to infer values for reduced dietary exposures to pesticide residues for babies.babyfood, hedonic analysis, organic foods, Demand and Price Analysis,
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