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The vibrational properties of octahedrane (C

Ab initio calculations are used to investigate the energetics of the reaction of C2(X 1Σ+ g) with CH4. The heat of reaction is predicted to be exothermic by 5·4 kcal mol-1 and the barrier height is 0·2 kcal mol-1 at the QCISD(T)/6-311++G(2df,2p)//UMP2/6-311G(2df,2p) level of theory. The implications of the results are discussed in terms of their importance to the atmospheric evolution of ethane oceans on Titan.

The electronic structure, vibrational spectra, and thermodynamic stability of CCCN and HCCCN have been determined using ab initio molecular orbital theory. The heat of formation for HCCCN was determined using Gaussian‐2 theory (G2) and was found to be 91.5±2 kcal mol−1. There is good agreement between the G2 value and that determined using an isodesmic reaction (i.e., one in which both the number and types of bonds are conserved), which yields 90.7±2 kcal mol−1. The heat of formation for the CCCN radical is 178.2±2 kcal mol−1. These data are used to compute the bond dissociation energies in HCCCN, D0(C–C) and D0(C–H), which are important in assessing the chemistry in Titan’s atmosphere, as well as in other interstellar media.

Peer review organizations (PRO) review the health care given to Medicare beneficiaries. If a PRO determines that a hospital admission was unnecessary, the hospital is not reimbursed for the medical care and the case is "denied." The average hospital denial rate on Ohio is 2%; however, the denial rate for hospital admissions of one day or less is 7.5%. An analysis of hospitals and diagnoses for one-day hospital admission denials was performed, showing that urban hospitals and disorders of the circulatory and digestive systems predominate. The inappropriate utilization of health care resources costs millions of dollars per year in Ohio and could be costing the nation billions of dollars. There is an urgent need to research why resources are used less effectively by some hospitals and for some diseases.

An analysis of Ohio's Medicare data base by the state's Peer Review Organization, using the most common diagnosis-related group in the Medicare population (heart failure and shock), from January 1, 1989 to January 1, 1991, identified 72 cases with confirmed quality-of-care problems. The analysis was performed to determine whether the majority of quality-of-care problems are related to systems or performance deficiencies. Study results indicated that health care workers are being inappropriately blamed for problems that are inherent in the health care system--74% of problems were related to inefficiencies in the health care delivery system, and 26% were determined to reflect performance problems.

Adjusted admission rates for respiratory distress (COPD, asthma, bronchitis, and pneumonia) varied up to 3.09-fold between the highest and lowest hos pital market areas in 1986 for the state of Ohio. Reasons for the variability can be determined through small area analysis techniques with the help of area physicians. Substantial improvements in the availability, delivery, and cost of respiratory care would reasonably be anticipated as a result of such analysis and feedback.

The CC bond dissociation energy (Do) in cyanogen is predicted using many‐body perturba‐ tion (MP) and quadratic configuration interaction theory [QCISD(T)]. The dissociation limit is poorly predicted with many‐body perturbation theory. At the QCISD(T)/6‐311G(3df)//QCISD(T)/ 6‐311G(2d) level of theory, the bond dissociation energy is predicted to be 132.8±2 kcal mol−1, which is in excellent agreement with experiment.

We show that our exact one‐dimensional Airy function formalism for studying electron resonant tunneling in multibarrier semiconductor heterostructures is an improvement on a previous calculation of Brennan and Summers [J. Appl. Phys. 61, 614 (1987)]. We also clearly demonstrate that our method gives better agreement with the numerical approach of Vassell, Lee, and Lockwood [J. Appl. Phys. 54, 5206 (1983)] in calculating the transmission coefficient T(E) and current density J(E) for multibarrier semiconductor heterostructures.