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The presence of several homologous series of porphyrins have been demonstrated in some oil shale rocks, shale oils, and petroleums. However, the application of microanalytical techniques (i.e., mass spectrometry and gas chromatography) to structure determination has been limited due to the low volatility of the porphyrin components. The authors report the synthesis of several novel Si(IV) etioporphyrin I derivatives and the effects that their various additional silicon ligands have on porphyrin volatility as measured by gas chromatography at normal pressure.

Diverse methods proposed for the acceleration of particles by means of collective fields are reviewed. A survey is made of the various currently active experimental programs devoted to investigating collective acceleration, and the present status of the research is briefly noted.

The ground-state wave function and energy of a finite system of interacting fermions are expanded in terms of multiple-particle excitations on an uncorrelated zero-order state. The resulting set of coupled equations constitutes a systematic variational generalization of Hartree-Fock theory. Comparison is made with many-body perturbation theory and it is shown that to any order the theory incorporates an infinite number of perturbation theory terms. Solutions of the equations for ground-state atomic systems are discussed and related to previous work using many-body perturbation theory. It is shown that the sums of perturbation terms necessary for convergence are automatically included in the equations for two-particle excitations. Application of the equations to open-shell atoms is described.

Although the detailed pathway of carbon, by which carbohydrates are formed from carbon dioxide during photosynthesis, has been established, comparatively little is known about the participation and transport of hydrogen in the complex series of reactions now known to be involved in photosynthesis. The transport of hydrogen may occur concurrently with the redox reactions of photosynthetic electron transport leading to the formation of ATP, as well as in the reduction of carbon dioxide. The participation of the chlorophylls, the carotenoids, the quinones, and other lipoid components in photosynthetic hydrogen transport has been the subject of considerable speculation. In an attempt to elucidate the pathway of hydrogen transport, we are studying the tritium labeling pattern in the lipid extracts of Rhodospirillum rubrum after the bacteria have been illuminated in growth medium containing tritiated water.

About 70,000 pictures of 2.45-GeV/c K{sup -}-p interactions have been obtained in the present 72-inch hydrogen bubble-chamber experiment. Approximately 24,000 events of all topologies except 1-, 2-, and 3-prong events have been measured, and 50% have been remeasured. They report here on a study of the production of known resonances in the reactions: (1) K{sup -} + p {yields} {Lambda} + {pi}{sup +} + {pi}{sup -}; (2) K{sup -} + p {yields} {Lambda} + {pi}{sup +} + {pi}{sup 0} + {pi}{sup -}. The cross section for production and number of events in reactions (1) and (2) are given in Table I.

We have successfully conducted a series of experiments involving scattering of high energy pions and protons from a target containing polarized protons. Results of some of these experiments were reported at this conference, and in the literature. Proton polarizations as high as 65% have been measured; the average polarization during sustained data-taking has been typically 45%.

General expressions are given for the field and its expansion coefficients produced by a two dimensional conductor structure surrounded by iron with a circular inside boundary. Saturation effects are described in terms of the tangential field at that boundary. The effects of the following types of perturbations are discussed: displacement, rotation and error excitation of a conductor, change of conductor shape, and modification of the inside contour of the iron. A design criterion is given to minimize the error fields associated with a displacement of the iron shell relative to the conductor structure. Expressions for the force and torque acting on a conductor are derived both for the unperturbed and perturbed magnet. Formulae are presented that allow convenient and fast evaluation of pertinent quantities with a computer when the structure is too complicated for hand computations.

Data are presented that show a marked species difference in the degree of damage and in the course of events seen in the bone marrow and peripheral blood after a given dose of radiation. The data taken together indicate strongly, but do not prove, that the picture seen results primarily from damage to the stem cell population. This damage to the stem cells is manifested later in the more mature differentiating cells of the marrow, and in the peripheral blood. The picture seen results both from death of stem cells, and also injury leading to reduced proliferative capacity, with later death of the injured stem cell and all of its progeny. Thus the picture seen is a result of both quantitative and qualitative changes resulting directly from the exposure of the stem cells, and species differences relative to sensitivity and time course of events appear to depend to a large degree on differential sensitivity of the bone marrow stem cell populations to death and injury. (auth)

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An analysis of the effect of mutual friction between normal fluid and superfluid in the flow of liquid He II through narrow channels under large temperature gradients was recently given by Craig, Keller, and Hammel. This analysis is based on the Gorter-Mellink thermodynamical equations. An alternative treatment of the problem is presented in which the conservation of entropy is introduced naturally into the theory at an early stage. The role played by entropy production in the processes involved in the thermohydrodynamics is thereby considerably clarified and a simple relation is given for an estimate of the relative importance of normal fluid dissipation and mutual friction dissipation. (auth)

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Article reprinted from The Harvard Business Review arguing that the reason for a lack of growth in an industry is due to a failure of management.

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A review is presented on vapor-liquid equilibria. Arnong the topics discussed are activity coefficients, consistency criteria, automatic computation, and gaseous mixtures. A bibliography of 18 references is included. (D.L.C.)

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