Centrifugally Obtained Artificial Gravity

Centrifugally obtained artificial gravity effects on space station crew performanc

Combustion instability prediction using a nonlinear bipropellant vaporization model

Combustion instability prediction using nonlinear bipropellant vaporization mode

Effects of street traffic noise in the night

The relationship between automobile traffic noise and the degree of disturbance experience experienced at night was explored through a random sample survey of 1600 individuals in rural and urban areas. The data obtained were used to establish threshold values

Coherent Excitation of the 6S1/2 to 5D3/2 Electric Quadrupole Transition in 138Ba+

The electric dipole-forbidden, quadrupole 6S1/2 5D3/2 transition in Ba+ near 2051 nm, with a natural linewidth of 13 mHz, is attractive for potential observation of parity non-conservation, and also as a clock transition for a barium ion optical frequency standard. This transition also offers a direct means of populating the metastable 5D3/2 state to measure the nuclear magnetic octupole moment in the odd barium isotopes. Light from a diode-pumped, solid state Tm,Ho:YLF laser operating at 2051 nm is used to coherently drive this transition between resolved Zeeman levels in a single trapped 138Ba+ ion. The frequency of the laser is stabilized to a high finesse Fabry Perot cavity at 1025 nm after being frequency doubled. Rabi oscillations on this transition indicate a laser-ion coherence time of 3 ms, most likely limited by ambient magnetic field fluctuations.Comment: 5 pages, 5 figure

Process Information Systems: A Synthesis of Two Independent Approaches

The development of process information systems to support analysis of energy (or mineral) resource development strategies has been a continuing concern within IIASA's WELMM (Water, Energy Land, Materials and Manpower) Project since 1977, The resulting process information system, the Facility Data Base, has demonstrated its viability in a number of application studies, both in-house and outside IIASA. Motivated by its experience in socio-economic resource modeling, the Structural Analysis Division at Statistics Canada has initiated a feasibility study on a data base of industrial process descriptions (completed in 1981): the Process Encyclopedia. The independent development and the joint interest in process information systems has led to collaboration between the Structural Analysis Division of Statistics Canada and the Energy and Resources Task of the Resources and Environment Area of IIASA. This paper (also published by Statistics Canada: Working Paper No. 81-12-01) documents the first results of this collaboration: a synthesis of the conclusions which led to the development of the two systems; of their main features and of the lessons learned from their design and implementation. The conceptual mapping developed between the Facility Data Base and the Process Encyclopedia and documented as an Appendix of this paper provides a basis for future exchange of information between the two systems and should be seen as a first step in promoting interdisciplinary and international process information exchange and system building

Phase operators, phase states and vector phase states for SU(3) and SU(2,1)

This paper focuses on phase operators, phase states and vector phase states for the sl(3) Lie algebra. We introduce a one-parameter generalized oscillator algebra A(k,2) which provides a unified scheme for dealing with su(3) (for k < 0), su(2,1) (for k > 0) and h(4) x h(4) (for k = 0) symmetries. Finite- and infinite-dimensional representations of A(k,2) are constructed for k < 0 and k > 0 or = 0, respectively. Phase operators associated with A(k,2) are defined and temporally stable phase states (as well as vector phase states) are constructed as eigenstates of these operators. Finally, we discuss a relation between quantized phase states and a quadratic discrete Fourier transform and show how to use these states for constructing mutually unbiased bases