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Experimental Determination of ETS Particle Deposition in a Low Ventilation Room

Description: Deposition on indoor surfaces is an important removal mechanism for tobacco smoke particles. We report measurements of deposition rates of environmental tobacco smoke particles in a room-size chamber. The deposition rates were determined from the changes in measured concentrations by correcting for the effects of coagulation and ventilation. The air flow turbulent intensity parameter was determined independently by measuring the air velocities in the chamber. Particles with diameters smaller th… more
Date: May 1, 1993
Creator: Xu, M.; Nematollahi, M.; Sextro, R. G.; Gadgil, A. J. & Nazaroff, W. W.
Partner: UNT Libraries Government Documents Department
open access

Space reactor fuel element testing in upgraded TREAT

Description: The testing of candidate fuel elements at prototypic operating conditions with respect to temperature, power density, hydrogen coolant flow rate, etc., a crucial component in the development and qualification of nuclear rocket engines based on the Particle Bed Reactor (PBR), NERVA-derivative, and other concepts. Such testing may be performed at existing reactors, or at new facilities. A scoping study has been performed to assess the feasibility of testing PBR based fuel elements at the TREAT re… more
Date: May 1, 1993
Creator: Todosow, M.; Bezler, P.; Ludewig, H. & Kato, W.Y.
Partner: UNT Libraries Government Documents Department
open access

Localized or Systemic {italic In Vivo} Heat-Inactivation of Human Immunodeficiency Virus (HIV): A Mathematical Analysis

Description: Temperatures as low as 42 C, maintained for a little as 25 minutes, inactivate {approx}25% of HIV. Furthermore, human immunodeficiency virus (HIV)-infected T-cells are more sensitive to heat than healthy lymphocytes and susceptibility increases when the cells are pre-sensitized by exposure to tumor necrosis factor. Thus, induction of a whole-body hyperthermia, or hyperthermia specifically limited to tissues having a high viral load, are potential antiviral therapies for acquired immunodeficienc… more
Date: December 15, 1993
Creator: Pennypacker, Carl R.; Perelson, A.S.; Nys, N.; Nelson, G. & Sessler, D.I.
Partner: UNT Libraries Government Documents Department
open access

An Efficient Microwave Power Source: Free-electron Laser Afterburner

Description: A kind of microwave power source, called a free-electron laser afterburner (FEL afterburner) which consists of a free-electron laser buncher and a slow-wave output structure sharing a magnetic wiggler field with the buncher, is proposed. The buncher and the slow-wave structure can operate in either a travelling-wave state or a standing-wave state. In the buncher, the wiggler field together with the radiation field makes an electron beam bunched, and in the slow-wave structure the wiggler field … more
Date: March 4, 1993
Creator: Wang, C. & Sessler, Andrew M.
Partner: UNT Libraries Government Documents Department
open access

Velocity and Attenuation Structure of the Geysers Geothermal Field, California

Description: The Geysers geothermal field is located in northern California and is one of the world's largest producers of electricity from geothermal energy. The resource consists of primarily dry steam which is produced from a low, porosity fractured graywacke. Over the last several years steam pressure at the Geysers has been dropping. Concern over decline of the resource has prompted research to understand its fundamental nature. A key issue is the distribution of fluid in the matrix of the reservoir ro… more
Date: January 1, 1993
Creator: Zucca, J. J.; Hutchings, L. J. & Kasameyer, P. W.
Partner: UNT Libraries Government Documents Department
open access

Impacts of a Sub-Slab Aggregate Layer and a Sub-Aggregate Membrane on Radon Entry Rate: A Numerical Study

Description: A subslab aggregate layer can increase the radon entry rate into a building by up to a factor of 5. We use a previously tested numerical technique to investigate and confirm this phenomenon. Then we demonstrate that a sub-aggregate membrane has the potential to significantly reduce the increase in radon entry rate due to the aggregate layer, even when a gap exists between the perimeter of the membrane and the footer. Such membranes greatly reduce diffusion of radon from the soil into the aggreg… more
Date: January 1, 1993
Creator: Bonnefous, Y. C.; Gadgil, A. J.; Revzan, K. L.; Fisk, W. J. & Riley, W. J.
Partner: UNT Libraries Government Documents Department
open access

Economic Analysis of Ilumex, A Project to Promote Energy-Efficient Residential Lighting in Mexico

Description: A higher penetration of compact fluorescent lamps (CFLs) for household lighting can reduce growth in peak electricity demand, reduce sales of subsidized electricity, and lessen environmental impacts. This paper describes an economic analysis of a project designed to promote high penetration rates of CFLs in two cities in Mexico. Our analysis indicates that the project will bring substantial net economic benefits to Mexico, the utility, and the average customer. In the absence of any subsidy to … more
Date: November 1, 1993
Creator: Sathaye, Jayant A.; Friedmann, R.; Meyers, S.; de Buen, O.; Gadgil, A. J.; Vargas, E. et al.
Partner: UNT Libraries Government Documents Department
open access

The Distribution of Exposure to Radon: Effects of Population Mobility

Description: The distribution of population exposures to radon, rather than the distribution of indoor radon concentrations, determines the fraction of population exposed to exceptionally high risk from radon exposures. Since this fraction at high risk has prompted the development of public policies on radon, it is important to first determine the magnitude of this fraction, and then how it much would decrease with different implementation program options for radon mitigation. This papers presents an approa… more
Date: January 1, 1993
Creator: Gadgil, A. J.; Rein, S.; Nero, A. V. & Wollenberg Jr., H. A.
Partner: UNT Libraries Government Documents Department
open access

Modeling Emissions of Volatile Organic Compounds from New Carpets

Description: A simple model is proposed to account for observed emissions of volatile organic compounds (VOCs) from new carpets. The model assumes that the VOCs originate predominantly in a uniform slab of polymer backing material. Parameters for the model (the initial concentration of a VOC in the polymer, a diffusion coefficient and an equilibrium polymer/air partition coefficient) are obtained from experimental data produced by a previous chamber study. The diffusion coefficients generally decrease as th… more
Date: February 1, 1993
Creator: Little, J. C.; Hodgson, A. T. & Gadgil, A. J.
Partner: UNT Libraries Government Documents Department
open access

Technical Design of Hadron Therapy Facilities

Description: Radiation therapy with hadron beams now has a 40-year track record at many accelerator laboratories around the world, essentially all of these originally physics-research oriented. The great promise shown for treating cancer has led the medical community to seek dedicated accelerator facilities in a hospital setting, where more rapid progress can be made in clinical research. This paper will discuss accelerator and beam characteristics relevant to hadron therapy, particularly as applied to hosp… more
Date: August 1, 1993
Creator: Alonso, J. R.
Partner: UNT Libraries Government Documents Department
open access

A beamline design and data acquisition with the 20-MeV, 20-ps electron beam for the higher-order mode studies of the APS SR-rf cavities

Description: A beamline has been designed and assembled to use the ANL Chemistry Division 20-MeV electron linac for the testing of higher-order mode excitation and damping in rf cavities. The beamline consists of two sections (a beam collimating section with a 1.5 inches-OD vacuum line, and a cavity test section with a 3 inches-OD vacuum line), separated by two double aluminum foil windows. The beam diagnostics consist of a stripline beam position monitor, integrating current transformers, fluorescent scree… more
Date: January 1, 1993
Creator: Song, J.; Nassiri, A. & Daly, R.
Partner: UNT Libraries Government Documents Department
open access

High precision beam alignment of electromagnetic wigglers

Description: The performance of Free-Electron Lasers depends critically on the quality of the alignment of the electron beam to the wiggler's magnetic axis and the deviation of this axis from a straight fine. The measurement of the electron beam position requires numerous beam position monitors in the wiggler, where space is at premium. The beam position measurement is used to set beam steerers for an orbit correction in the wiggler. The authors propose an alternative high precision alignment method in whic… more
Date: January 1, 1993
Creator: Ben-Zvi, Ilan & Qiu, X. Z.
Partner: UNT Libraries Government Documents Department
open access

Diffuse scattering and image contrast of tweed in superconducting oxides: A simulation and interpretation

Description: Monte Carlo simulations were performed with a lattice gas model which represents the interactions between oxygen atoms in YBa[sub 2](Cu[sub 1-x]M[sub x])[sub 3]O[sub 7+[delta]] (M=Fe, Co, or Al, 0.03< [times] <0.l) system. The amplitudes of concentration waves/displacement waves obtained from these simulations then were used to calculate the intensity of the diffuse scattering of tweed seen in the electron diffraction pattern. The characteristic features of the tweed image were produced by calc… more
Date: January 1, 1993
Creator: Zhu, Yimei & Cai, Zhi-Xiong.
Partner: UNT Libraries Government Documents Department
open access

Determination of the energy of suprathermal electrons during lower hybrid current drive on PBX-M

Description: Suprathermal electrons are diagnosed by a hard x-ray pinhole camera during lower hybrid current drive on PBX-M. The experimental hard x-ray images are compared with simulated images, which result from an integration of the relativistic bremsstrahlung along lines-of-sight through the bean-shaped plasma. Images with centrally peaked and radially hollow radiation profiles are easily distinguished. The energy distribution of the suprathermal electrons is analyzed by comparing images taken with diff… more
Date: June 1, 1993
Creator: Von Goeler, S.; Bernabei, S.; Davis, W.; Ignat, D.; Kaita, R.; Roney, P. et al.
Partner: UNT Libraries Government Documents Department
open access

Reorientation of misfit dislocations during annealing in InGaAs/GaAs(001) interfaces

Description: Transmission electron microscopy is applied to investigate the effect of postannealing on misfit dislocations in an In[sup 0.2]Ga[sup 0.8]As/GaAs(001) heterostructure. An orthogonal array of 60[degree] dislocations along [110] and [110] directions was observed in the interfaces of the samples grown by MBE at 520C. When the as-grown samples were annealed at temperatures ranging from 600 to 800C, the 60[degree] dislocations were gradually reoriented by dislocation reactions occurring at the 90[de… more
Date: April 1, 1993
Creator: Chen, Y.; Liliental-Weber, Z.; Washburn, J. (Lawrence Berkeley Lab., CA (United States)); Klem, J.F. & Tsao, J.Y. (Sandia National Labs., Albuquerque, NM (United States))
Partner: UNT Libraries Government Documents Department
open access

Operator overloading as an enabling technology for automatic differentiation

Description: We present an example of the science that is enabled by object-oriented programming techniques. Scientific computation often needs derivatives for solving nonlinear systems such as those arising in many PDE algorithms, optimization, parameter identification, stiff ordinary differential equations, or sensitivity analysis. Automatic differentiation computes derivatives accurately and efficiently by applying the chain rule to each arithmetic operation or elementary function. Operator overloading e… more
Date: January 1, 1993
Creator: Corliss, G.F. (Marquette Univ., Milwaukee, WI (United States) Argonne National Lab., IL (United States)) & Griewank, A. (Argonne National Lab., IL (United States))
Partner: UNT Libraries Government Documents Department
open access

An improved, explosively actuated closing switch for pulsed power applications

Description: An improved, explosively actuated closing switch has been developed for the Pegasus II capacitor bank. The new switch design uses an annular metal jet as the switch contact. It has lower resistance and inductance at early time than the original design. A parallel array of 24 switches on Pegasus II has a resistance of less than 10 [mu][Omega] after 300 ns. Measured time behaviors include an intrinsic jitter of 50 ns and a switching delay that depends inversely on the applied voltage.
Date: January 1, 1993
Creator: Parker, J. V.; Bartsch, R. R.; Cochrane, J. C. & Marsh, S. P.
Partner: UNT Libraries Government Documents Department
open access

ISO standards on the evaluation of contamination

Description: The International Organization for Standardization (ISO) develops radiation calibration standards through Subcommittee 2 (titled Radiation Protection'') of Technical Committee 85 (ISO/TC85/SC2). The subcommittee has also developed standards providing guidance on the performance of measurements. ISO/TC85/SC2 consists of international technical experts who represent their countries through the international consensus process in providing guidance in several radiation protection areas. The purpose… more
Date: January 1, 1993
Creator: Swinth, K.L. (Pacific Northwest Lab., Richland, WA (United States)) & Tamberg, T.A. (Bundesanstalt fuer Materialforschung und -pruefung, Berlin (Germany))
Partner: UNT Libraries Government Documents Department
open access

Failure and factors of safety in piping system design

Description: An important body of test and performance data on the behavior of piping systems has led to an ongoing reassessment of the code stress allowables and their safety margin. The codes stress allowables, and their factors of safety, are developed from limits on the incipient yield (for ductile materials), or incipient rupture (for brittle materials), of a test specimen loaded in simple tension. In this paper, we examine the failure theories introduced in the B31 and ASME III codes for piping and th… more
Date: January 1, 1993
Creator: Antaki, G. A.
Partner: UNT Libraries Government Documents Department
open access

Energy efficiency and the environment: Innovative ways to improve air quality in the Los Angeles Basin

Description: This paper focuses on novel, innovative approaches for reducing or delaying the production of photochemical smog in the Los Angeles Basin. These approaches include modifying the surface characteristics of the basin by increasing surface albedo and an extensive tree-planting program. The changes in surface conditions are designed to reduce the basin air temperatures, especially during the summer months, which will result in two possible effects. First, a decrease in temperature would lead to a r… more
Date: February 1, 1993
Creator: Ritschard, R.
Partner: UNT Libraries Government Documents Department
open access

Theoretical Crystallography With the Advanced Visualization System

Description: Space is an Application Visualization System (AVS) graphics module designed for crystallographic and molecular research. The program can handle molecules, two-dimensional periodic systems, and three-dimensional periodic systems, all referred to in the paper as models. Using several methods, the user can select atoms, groups of atoms, or entire molecules. Selections can be moved, copied, deleted, and merged. An important feature of Space is the crystallography component. The program allows the u… more
Date: May 1, 1993
Creator: Younkin, C. R.; Thornton, E. N.; Nicholas, J. B.; Jones, D. R. & Hess, A. C.
Partner: UNT Libraries Government Documents Department
open access

A risk-based approach to cost-benefit analysis of software safety activities

Description: Assumptions about the economics of making a system safe are usually not explicitly stated in industrial and software models of safety-critical systems. These assumptions span a wide spectrum of economic tradeoffs with respect to resources expended to make a system safe. The missing component in these models that is necessary for capturing the effect of economic tradeoffs is risk. A qualitative risk-based software safety model is proposed that combines features of industrial and software systems… more
Date: January 1, 1993
Creator: Fortier, S.C. (Intermetrics, Inc., McLean, VA (United States)) & Michael, J.B. (Argonne National Lab., IL (United States))
Partner: UNT Libraries Government Documents Department
open access

Fin-efficiency calculation for condensation in the presence of noncondensable gases

Description: Plate-fin heat exchangers are being considered for many condenser applications. They are commonly used for the gas-separation process because they can provide a high thermal performance to obtain a low mean-temperature difference, essential for the gas-separation process. Plate-fin heat exchangers are also considered for the heat-pump system using nonazeotropic refrigerant mixtures. The brazed plate-fin condenser was considered to be a leading candidate for the Ocean Thermal Energy Conversion (… more
Date: January 1, 1993
Creator: Panchal, C.B.
Partner: UNT Libraries Government Documents Department
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