34,320 research outputs found
Physiology of man and animals in the Tenth Five-Year Plan: Proceedings of the Thirteenth Congress of the I. P. Pavlov All-Union Physiological Society
Research in the field of animal and human physiology is reviewed. The following topics on problems of physiological science and related fields of knowledge are discussed: neurophysiology and higher nervous activity, physiology of sensory systems, physiology of visceral systems, evolutionary and ecological physiology, physiological cybernetics, computer application in physiology, information support of physiological research, history and theory of development of physiology. Also discussed were: artificial intelligence, physiological problems of reflex therapy, correlation of structure and function of the brain, adaptation and activity, microcirculation, and physiological studies in nerve and mental diseases
An investigation of the suitability of white rats for sub-orbital studies of behavior in a gravity field
Suitability of white rats for suborbital studies of behavior in gravity field
Deterministic cavity quantum electrodynamics with trapped ions
We have employed radio-frequency trapping to localize a single 40Ca+-ion in a high-finesse optical cavity. By means of laser Doppler cooling, the position spread of the ion's wavefunction along the cavity axis was reduced to 42 nm, a fraction of the resonance wavelength of ionized calcium (λ = 397 nm). By controlling the position of the ion in the optical field, continuous and completely deterministic coupling of ion and field was realized. The precise three-dimensional location of the ion in the cavity was measured by observing the fluorescent light emitted upon excitation in the cavity field. The single-ion system is ideally suited to implement cavity quantum electrodynamics under cw conditions. To this end we operate the cavity on the D3/2–P1/2 transition of 40Ca+ (λ = 866 nm). Applications include the controlled generation of single-photon pulses with high efficiency and two-ion quantum gates
Microstructural properties of non-supported microporous ceramic membrane top-layers obtained by the sol-gel process
Dried and calcined non-supported membrane top-layers of SiO2, SiO2/TiO2, SiO2/ZrO2 (10, 20 and 30 mol% TiO2 and ZrO2, respectively) and SiO2/Al2O3 (10 mol% AlO1.5) were prepared using acid catalyzed hydrolysis and condensation of alkoxides in ethanol. The microstructure was determined using nitrogen physisorption. The modified Horváth-Kawazoe model for nitrogen adsorption in cylindrical pores was used for pore size assessment. SiO2 non-supported membrane top layers were 100% microporous with an average porosity of 30¿37%, depending on drying conditions. The bimodal pore size distribution shows a maximum at an effective pore diameter of 0.5 nm, and a broader tail with a weaker maximum around 0.75 nm. Microporous non-supported binary systems can be prepared with porosities between 15 and 40%. The high reactivity of the Ti, Zr, Al-alkoxides requires carefully chosen conditions. Too much water results in dense materials. The pore size distributions (PSDs) of the binary systems resemble the PSDs for silica
Permeation and separation studies on microporous sol-gel modified ceramic membranes
Permeation and separation experiments with H2, CO2, O2, N2, CH4 and isobutane with microporous sol-gel modified supported ceramic membranes were performed to determine the gas transport characteristics and the hydrogen separation performance of these membranes. It is found that the permeation is activated, and for defectfree membranes the apparent activation energies are in the ranges 13¿15 and 5¿6 kJ mol¿1 for H2 and CO2, respectively. Correction for the pressure drop over the support results in apparent activation energies for the silica top-layer on the order of 17¿22 and 10¿15 kJ mol¿1 for H2 and CO2 respectively. Due to the very thin top-layer, the permeation is relatively high, with representative values of 6·10¿7 and 20·10¿7 mol m¿2s¿1 Pa¿1 for H2 at 25 and 200°C, respectively. The H2 permeation is almost pressure-independent up to pressures of at least 5 bar. Typical separation factors for H2---CH4 and H2---isobutane are approximately ¿40 and ¿200, respectively, at 200°C for high-quality membranes. For moderate-quality membranes the H2---CH4 separation factor is around 10, while the H2---isobutane separation factor remains at a high value of around 100 at 200°C and 120 at 300°C
Time domain simulations of dynamic river networks
The problem of simulating a river network is considered. A river network is considered to comprise of rivers, dams/lakes as well as weirs. We suggest a numerical approach with specific features that enable the correct representation of these assets. For each river the flow of water is described by the shallow water equations which is a system of hyperbolic partial differential equations and at the junctions of the rivers, suitable coupling conditions, viewed as interior boundary conditions are used to couple the dynamics. A different model for the dams is also presented. Numerical test cases are presented which show that the model is able to reproduce the expected dynamics of the system.
Other aspects of the modelling such as rainfall, run-off, overflow/flooding, evaporation, absorption/seepage, bed-slopes, bed friction have not been incorporated in the model due to their specific nature
Nonprofit Organizations and the Nevada Economy: An analysis of the employment, economic impact, and scope of the nonprofit sector in Nevada
The Nevada nonprofit sector plays an important role in the state’s economy. This research report examines the role of nonprofit organizations in the economy and details regional differences in terms of employment and economic impact in the state
- …