84 research outputs found
Raman and infrared spectra of dimethyl ether 13C-isotopologue (CH3O13CH3) from a CCSD(T) potential energy surface
So far, no experimental data of the infrared and Raman spectra of 13C isotopologue of dimethyl ether are available. With the aim of providing some clues of its low-lying vibrational bands and with the hope of contributing in a next spectral analysis, a number of vibrational transition frequencies below 300 cm−1 of the infrared spectrum and around 400 cm−1 of the Raman spectrum have been predicted and their assignments were proposed. Calculations were carried out through an ab initio three dimensional potential energy surface based on a previously reported one for the most abundant dimethyl ether isotopologue (M. Villa et al., J. Phys. Chem. A 115 (2011) 13573). The potential function was vibrationally corrected and computed with a highly correlated CCSD(T) method involving the COC bending angle and the two large amplitude CH3 internal rotation degrees of freedom. Also, the Hamiltonian parameters could represent a support for the spectral characterization of this species. Although the computed vibrational term values are expected to be very accurate, an empirical adjustment of the Hamiltonian has been performed with the purpose of anticipating some workable corrections to any possible divergence of the vibrational frequencies. Also, the symmetry breaking derived from the isotopic substitution of 13C in the dimethyl ether was taken into account when the symmetrization procedure was applied
ChemInform Abstract: Microwave Spectrum and Quadrupole Coupling Constant Tensor of gauche- Isobutyl Chloride.
Body ideals and body dissatisfaction among a community sample of 1330 ethnically diverse adolescents on Kauai, Hawaii
Thesis (M.S.)--University of Hawaii at Manoa, 2007.Includes bibliographical references (leaves 18-20).vii, 20 leaves, bound col. ill. 29 cmIntroduction: Body dissatisfaction (BD), a robust risk factor for eating disorders, is occurring at younger rages and among a wider range of socioeconomic and cultural groups. Objectives: To describe body ideals and prevalence of body dissatisfaction among an ethnically diverse population of male and female students. Method: An anonymous cross-sectional survey including biographical information and the figure drawing screen was distributed to 71h through 121h grade students. Results: Of the 1330 completed surveys, 19% of students were significantly dissatisfied with their bodies. Males were at greater risk than females for total BD (25.8% vs. 13.3%; p<O.OOOI) and for BD in the direction of wanting to be larger (1 1.3% vs. 2.3%; p<O.OOOI). Males and females were at similar risk for BD in the direction of wanting to be thinner (14.6% vs. 11.6%; p=O.II). Prevalence of BD in the direction of wanting to be thinner was statistically different among ethnic groups. There were no significant differences in BD based on grade level or SES. Conclusions: BD is common among male and female adolescents, with certain ethnic groups being at higher risk. Studies to illustrate risk and protective factors among different groups may help tailor prevention strategies. Further research is also needed to better understand the mechanisms for and potential outcomes of the bidirectional BD seen in males
ChemInform Abstract: Microwave Spectrum and Quadrupole Coupling Constant Tensor of gauche- Isobutyl Iodide.
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