358 research outputs found

    The Design, Construction, and Performance of a Magnetic Focusing, Semi-Circular, Low Energy Beta-Ray Spectrometer

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    A semi-circular beta-ray spectrometer (Fig. 1) has been constructed for operation between 2 and 120 kev electron energy. This instrument was designed to supplement the ring- focusing beta-ray spectrometer whose lower limit is approximately 25 kev. The 180° spectrometer has an electron trajectory radius of 12 cm. The field is produced by two iron free coils spaced to give a nearly homogeneous field (with some second order focusing) in the region of the electron trajectories . The field current is supplied by a one kw motor- generator set. Stabilization is obtained to 2 parts in 10, 000 with a rotating electro- mechanical unit and an electronic servo system. Source and Geiger counter window dimensions for a standard resolution of 0 .8% are 0.1 cm x 4 cm. With a 10 Ό.g/cm^2 formvar window, transmission is assured down to 2 kev electron energy. A recording potentiometer traces the counting rate vs. electron energy. Several examples of chart recordings are reproduced to illustrate the performance of the semi- circular beta-ray spectrometer

    The Fundamental Constants of Physics, Vol. 1 of Interscience Monographs in Physics & Astronomy [book review]

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    Book review of: The Fundamental Constants of Physics. Vol. 1 of Interscience Monographs in Physics & Astronomy. By E. Richard Cohen, Kenneth M. Crowe, Jesse W. M. DuMond. 287 pp. Interscience Publishers, Inc., New York, 1957. Reviewed by H. Mendlowitz, National Bureau of Standards

    A Determination of the Wave Forms and Laws of Propagation and Dissipation of Ballistic Shock Waves

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    Experiments to ascertain the wave forms and laws of propagation and dissipation of ballistic shock waves to large distances (80 yards) from the bullet trajectory are described. Calibers 0.30, 0.50, 20 mm, and 40 mm were studied. In every case an N‐shaped wave profile was observed consisting of a sudden rise in pressure, the “head discontinuity,” followed by an approximately linear decline to a pressure about equally far below atmospheric and then a second sudden return, the “tail discontinuity,” to atmospheric pressure. The peak amplitudes of this disturbance are found to diminish about as the inverse 3/4 power of the miss‐distance (perpendicular distance from the trajectory) while the period Tâ€Č (measured between the discontinuous fronts) increases about as the 1/4 power of the miss‐distance for calibers 0.30, 0.50, and 20 mm. For 40‐mm shells the amplitude decays a little faster, about as the inverse 0.9 power of miss‐distance over the range studied. A theory taking account of the dissipation of the N‐wave energy into heat is developed to explain the observed behavior. A method of measuring absolute N‐wave amplitudes by observing the rate of change of period Tâ€Č with propagation is described. The theory leads to an absolute relationship at large distances between distance, amplitude, and period in which no arbitrary constants appear

    Dietary garlic and hip osteoarthritis: evidence of a protective effect and putative mechanism of action

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    Background Patterns of food intake and prevalent osteoarthritis of the hand, hip, and knee were studied using the twin design to limit the effect of confounding factors. Compounds found in associated food groups were further studied in vitro. Methods Cross-sectional study conducted in a large population-based volunteer cohort of twins. Food intake was evaluated using the Food Frequency Questionnaire; OA was determined using plain radiographs. Analyses were adjusted for age, BMI and physical activity. Subsequent in vitro studies examined the effects of allium-derived compounds on the expression of matrix-degrading proteases in SW1353 chondrosarcoma cells. Results Data were available, depending on phenotype, for 654-1082 of 1086 female twins (median age 58.9 years; range 46-77). Trends in dietary analysis revealed a specific pattern of dietary intake, that high in fruit and vegetables, showed an inverse association with hip OA (p = 0.022). Consumption of 'non-citrus fruit' (p = 0.015) and 'alliums' (p = 0.029) had the strongest protective effect. Alliums contain diallyl disulphide which was shown to abrogate cytokine-induced matrix metalloproteinase expression. Conclusions Studies of diet are notorious for their confounding by lifestyle effects. While taking account of BMI, the data show an independent effect of a diet high in fruit and vegetables, suggesting it to be protective against radiographic hip OA. Furthermore, diallyl disulphide, a compound found in garlic and other alliums, represses the expression of matrix-degrading proteases in chondrocyte-like cells, providing a potential mechanism of action

    Internally Electrodynamic Particle Model: Its Experimental Basis and Its Predictions

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    The internally electrodynamic (IED) particle model was derived based on overall experimental observations, with the IED process itself being built directly on three experimental facts, a) electric charges present with all material particles, b) an accelerated charge generates electromagnetic waves according to Maxwell's equations and Planck energy equation and c) source motion produces Doppler effect. A set of well-known basic particle equations and properties become predictable based on first principles solutions for the IED process; several key solutions achieved are outlined, including the de Broglie phase wave, de Broglie relations, Schr\"odinger equation, mass, Einstein mass-energy relation, Newton's law of gravity, single particle self interference, and electromagnetic radiation and absorption; these equations and properties have long been broadly experimentally validated or demonstrated. A specific solution also predicts the Doebner-Goldin equation which emerges to represent a form of long-sought quantum wave equation including gravity. A critical review of the key experiments is given which suggests that the IED process underlies the basic particle equations and properties not just sufficiently but also necessarily.Comment: Presentation at the 27th Int Colloq on Group Theo Meth in Phys, 200
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