A critical analysis of the Grad approximation for closing out the magnetohydrodynamic equations for plasmas

Error analysis on moment distribution functions of magnetohydrodynamic plasma equation

A semiempirical collision model for plasmas

Semiempirical collision model for plasma

An interpretation of photometric parameters of bright desert regions of Mars and their dependence on wave length

Photometric data from the bright desert areas of Mars were used to determine the dependence of the three photometric parameters of the photometric function on wavelength and to provide qualitative predictions about the physical properties of the surface. Knowledge of the parameters allowed the brightness of these areas of Mars to be determined for any scattering geometry in the wavelength range of 0.45 to 0.70 micron. The changes that occur in the photometric parameters due to changes in wavelength were shown to be consistent with their physical interpretations, and the predictions of surface properties were shown to be consistent with conditions expected to exist in these regions of Mars. The photometric function was shown to have potential as a diagnostic tool for the qualitative determination of surface properties, and the consistency of the behavior of the photometric parameters was considered to be support for the validity of the photometric function

A photometric function for diffuse reflection by particulate materials

A photometric function is proposed to describe the diffuse reflection of radiation by particulate materials. Both multiple scattering and the dominant effects of particle shadowing are included and the function is verified by comparisons with the photometries of laboratory surfaces. Brightness measurements of planetary and other diffusely scattering surfaces can be used to calculate the brightness for geometries other than those used in the measurements and for which the Minnaert function does not apply. The measurements also can be directly related to such surface characteristics as particle size, single-particle albedo, and compactness

Corporate Governance: Shareholder Rights And Firm Performance

In the 21st century, greater attention is being paid to the issue of shareholder rights and corporate governance in U.S. corporations by regulators, shareholders and the general public.  A previous paper by the authors finds that the level of shareholder rights generally has not increased and may have declined amongst the S&P 500 companies, despite the recent legislative and regulatory reforms.  Evidence suggests that instead firms are searching for an optimum level of shareholder rights that balances the risks and rewards of greater shareholder rights.  This study investigates the financial performance of firms with greater shareholder rights (GSR) and contrasts it with that of firms with lower shareholder rights (LSR).  This paper finds that GSR firms may perform better on some financial criteria, in absolute terms, but when adjusted for volatility, LSR firms may perform better, contrary to the conventional wisdom

A preliminary study of ester oxidation on an aluminum surface using chemiluminescence

The oxidation characteristics of a pure ester (trimethyolpropane triheptanoate) were studied by using a chemiluminescence technique. Tests were run in a thin-film micro-oxidation apparatus with an aluminum alloy catalyst. Conditions included a pure oxygen atmosphere and a temperature range of 176 to 206 C. Results indicated that oxidation of the ester (containing 10 to the minus 3 power M diphenylanthracene as an intensifier) was accompanied by emission of light. The maximum intensity of light emission (I sub max) was a function of the amount of ester, the concentration of intensifier, and the test temperature. The induction period or the time to reach one-half of maximum intensity (t sub 1/2) was an inverse function of test temperature. Decreases in light emission at the later stages of a test were caused by depletion of the intensifier

Values of the photometric parameters of Mars and their interpretation

Photometric data for the Martian disk obtained by Thorpe from television-camera pictures taken by Mariner 9 were used to derive values for the parameters in the photometric function. The photometric function can be applied to Mars and to the design of cameras for photography of Mars. Values of the parameters are for one wavelength only, 0.56 micros and are average or effective values for the Martian disk. The values derived were interpreted to provide semi-quantitative information on the soil. The results do not disagree with other indications that the effective mean diameter of the surface particles is about 400 micros. Another result is that the mean intercenter spacing of adjacent particles may be about 4/3 of the mean diameter

Product Focus versus Diversification: Estimates of X-Efficiency for the US Life Insurance Industry

Using data for the life insurance industry during 1990-1995, we empirically test for a relationship between a firm's output choice and measures of X-efficiency. Our empirical evidence suggests that diversification across multiple insurance and investment product lines resulted in greater X-efficiency than a more focused production strategy. The analysis in this article is consistent with the proposition that managers of multiproduct firms are able to achieve greater cost efficiencies than their counterparts in more focused firms by sharing inputs and efficiently allocating resources across product lines in response to changing industry conditions. Our findings are important since they justify the existence of multiproduct firms in the absence of cost complementarities and identify product diversification as a source of efficiency in the life insurance industry that should be recognized by managers, policyholders, and regulators.

A numerical simplification and alternative to the RKR method for diatomic molecules

Numerical simplification and alternative to Rydberg-Klein-Refs method for diatomic molecule

Demutualization in the Life Insurance Industry: A Study of Effectiveness

The regulatory and competitive environment in the life insurance industry has changed dramatically in recent years. We investigate the effectiveness of demutualization as a strategic response to the challenges posed by these sweeping changes. The study finds that the demutualized firms generally have implemented a successful strategy based on higher growth, greater profitability, cost effectiveness and shifts in product mix. Also, we find that management takes greater risk in the investment portfolio. In addition, demutualization unlocks value lying dormant in the mutuals’ surplus. The paper concludes that the demutualized firms have generated substantial excess returns over the several market indexes, creating significant economic value