Separation of gas mixtures by centrifugation

Magnetohydrodynamic (MHD) centrifuge utilizing electric currents and magnetic fields produces a magnetic force which develops supersonic rotational velocities in gas mixtures. Device is superior to ordinary centrifuges because rotation of gas mixture is produced by MHD force rather than mechanical means

Returns to Soybean Producers from Investments in Promotion and Research

U.S. soybean producers have been cooperatively investing in both production research and demand promotion for nearly four decades to enhance the profitability and international competitiveness of their industry. Have producers benefitted from their contributions to soybean checkoff program activities over the years? How has the return to investments in soybean production research compared to that of soybean demand promotion investments? The overall positive returns to producers over the study period resulted primarily from promotion activities. Production research contributed negatively to overall producer returns from soybean checkoff investments.Agribusiness,

Neutron spectral measurements in the upper atmosphere

An experiment to measure neutrons in the upper atmosphere was performed on a balloon flight from Palestine, Texas, at an altitude of about 32 km. The experimental arrangement is discussed briefly, and results of a preliminary analysis of the data for neutrons in the energy range 3 to 30 MeV are given

Study of shuttle imaging microwave system antenna. Volume 1: Conceptual design

A detailed preliminary design and complete performance evaluation are presented of an 11-channel large aperture scanning radiometer antenna for the shuttle imaging microwave system (SIMS) program. Provisions for interfacing the antenna with the space shuttle orbiter are presented and discussed. A program plan for hardware development and a rough order of magnitude (ROM) cost are also included. The conceptual design of the antenna is presented. It consists of a four-meter diameter parabolic torus main reflector, which is a graphite/epoxy shell supported by a graphite/epoxy truss. A rotating feed wheel assembly supports six Gregorian subreflectors covering the upper eight frequency channels from 6.6 GHz through 118.7 GHz, and two three-channel prime forms feed assemblies for 0.6, 1.4, and 2.7 GHz. The feed wheel assembly also holds the radiometers and power supplies, and a drive system using a 400 Hz synchronous motor is described. The RF analysis of the antenna is performed using physical optics procedures for both the dual reflector Gregorian concept and the single reflector prime focus concept. A unique aberration correcting feed for 2.7 GHz is analyzed. A structural analysis is also included. The analyses indicate that the antenna will meet system requirements

Hydrogen contamination in Ge-doped SiO[sub 2] thin films prepared by helicon activated reactive evaporation

Germanium-doped silicon oxidethin films were deposited at low temperature by using an improved helicon plasma assisted reactive evaporation technique. The origins of hydrogen contamination in the film were investigated, and were found to be H incorporation during deposition and postdeposition water absorption. The H incorporation during deposition was avoided by using an effective method to eliminate the residual hydrogen present in the depositionsystem. The microstructure, chemical bonds, chemical etch rate, and optical index of the films were studied as a function of the deposition conditions. Granular microstructures were observed in low-density films, and were found to be the cause of postdeposition water absorption. The granular microstructure was eliminated and the film was densified by increasing the helicon plasma power and substrate bias during deposition. A high-density film was shown to have no postdeposition water absorption and no OH detected by using a Fourier-transform infrared spectrometer

Triangular buckling patterns of twisted inextensible strips

When twisting a strip of paper or acetate under high longitudinal tension, one observes, at some critical load, a buckling of the strip into a regular triangular pattern. Very similar triangular facets have recently been observed in solutions to a new set of geometrically-exact equations describing the equilibrium shape of thin inextensible elastic strips. Here we formulate a modified boundary-value problem for these equations and construct post-buckling solutions in good agreement with the observed pattern in twisted strips. We also study the force-extension and moment-twist behaviour of these strips by varying the mode number n of triangular facets

Nudging investors big and small toward better decisions

Investors significantly reduce their future returns by selecting mutual funds with higher fees, allured by higher past returns that do not predict future performance. This suboptimal behavior, which can roughly halve an investor’s retirement savings, is driven by 2 psychological factors. One factor is difficulty comprehending rate information, which is critical given that mutual fund fees and returns are typically communicated in percentages. A second factor is devaluing small differences in returns or fees (i.e., a peanuts effect). These 2 factors interact such that large investors benefit when fees are stated in currency (as opposed to percentages), whereas small investors benefit from returns stated in currency. These striking results suggest behavioral interventions that are tailored specifically for small and large investors

Spin observables and the determination of the parity of Θ+\Theta^+ in photoproduction reactions

Spin observables in the photoproduction of the $\Theta^+$ are explored for the purpose of determining the parity of the $\Theta^+$. Based on reflection symmetry in the scattering plane, we show that certain spin observables in the photoproduction of the $\Theta^+$ can be related directly to its parity. We also show that measurements of both the target nucleon asymmetry and the $\Theta^+$ polarization may be useful in determining the parity of $\Theta^+$ in a model-independent way. Furthermore, we show that no combination of spin observables involving only the polarization of the photon and/or nucleon in the initial state can determine the parity of $\Theta^+$ unambiguously.Comment: LaTeX, 11 pages, minor revisio