Membrane Separation Systems---a Research and Development Needs Assessment (open access)

Membrane Separation Systems---a Research and Development Needs Assessment

Membrane based separation technology, a relative newcomer on the separations scene, has demonstrated the potential of saving enormous amounts of energy in the processing industries if substituted for conventional separation systems. Over 1 quad annually, out of 2.6, can possibly be saved in liquid-to-gas separations, alone, if membrane separation systems gain wider acceptance, according to a recent DOE/OIP (DOE/NBM-80027730 (1986)) study. In recent years great strides have been made in the field and offer even greater energy savings in the future when substituted for other conventional separation techniques such as distillation, evaporation, filtration, sedimentation, and absorption. An assessment was conducted by a group of six internationally known membrane separations experts who examined the worldwide status of research in the seven major membrane areas. This encompassed four mature technology areas: reverse osmosis, micorfiltration, ultrafiltration, and electrodialysis; two developing areas: gas separation and and pervaporation; and one emerging technology: facilitated transport. Particular attention was paid to identifying the innovative processes currently emerging, and even further improvements which could gain wider acceptance for the more mature membrane technology. The topics that were pointed out as having the greatest research emphasis are pervaporation for organic-organic separations; gas separation; micorfiltration; an oxidant-resistant reverse osmosis membrane; …
Date: April 1990
Creator: Baker, R. W.; Cussler, E. L.; Eykamp, W.; Koros, W. J.; Riley, R. L. & Strathmann, H.
Object Type: Report
System: The UNT Digital Library
Development of a Biological Treatment System for Hanford Groundwater Remediation (open access)

Development of a Biological Treatment System for Hanford Groundwater Remediation

The primary objective of the biological treatment program is to develop and demonstrate a biological process for Hanford groundwater remediation that is capable of nitrate (NO {sub 3}{sup {minus}}) and organic contaminant destruction. Biodenitrification using facultative anaerobic microorganisms is a promising technology for the simultaneous removal of NO{sub 3}{sup {minus}} and organics from contaminated aqueous streams. During FY 1989, microbial consortium from the Hanford groundwater was shown to degrade both NO{sub 3}{sup {minus}} and carbon tetrachloride (CC1{sub 4}). A pilot-scale treatment system was subsequently designed and constructed based on the results of laboratory- and bench-scale testing. The pilot-scale system demonstrated continuous degradation of NO{sub 3}{sup {minus}} and CC1{sub 4} in a simulated groundwater. This report summarizes the results of biological groundwater treatment studies performed during FY 1989 at the pilot-, laboratory-, and bench-scales. Pilot-scale test were conducted using a simulate Hanford groundwater with a continuous stirred-tank bioreactor (CSTR) and a fluidized-bed bioreactor that was added to the pilot-scale treatment system in FY 1989. Laboratory test focused on the degradation of CC1{sub 4} and on the microbial toxicity from CC1{sub 4}, hexavalent chromium (Cr{plus} {sup 6}), and cyanide (CN){sup {minus}} 15 refs., 18 figs., 1 tab.
Date: April 1990
Creator: Brouns, T. M.; Koegler, S. S.; Heath, W. O.; Fredrickson, J. K.; Stensel, H. D.; Johnstone, D. L. et al.
Object Type: Report
System: The UNT Digital Library
Results of investigation at the Ahuachapan Geothermal Field, El Salvador (open access)

Results of investigation at the Ahuachapan Geothermal Field, El Salvador

The Ahuachapan Geothermal Field (AGF) is a 95 megawatt geothemal-sourced power-plant operated by the Comision Ejecutiva Hidroelectrica del Rio Lempa (CEL) of El Salvador. During the past decade, as part of an effort to increase in situ thermal reserves in order to realize the full generation capacity of the AGF, extensive surface geophysical coverage has been obtained over the AGF and the prospective Chipilapa area to the east. The geophysical surveys were performed to determine physical property characteristics of the known reservoir and then to search for similar characteristics in the Chipilapa area. A secondary objective was to evaluate the surface recharge area in the highlands to the south of the AGF. The principal surface electrical geophysical methods used during this period were DC resistivity and magnetotellurics. Three available data sets have been reinterpreted using drillhole control to help form geophysical models of the area. The geophysical models are compared with the geologic interpretations.
Date: April 1, 1990
Creator: Fink, J.B. (HydroGeophysics, Tucson, AZ (United States))
Object Type: Report
System: The UNT Digital Library
Motion control of the accumulator flying wires (open access)

Motion control of the accumulator flying wires

Flying wire systems for the Fermilab Accumulator are being constructed in order to measure the transverse beam profiles during stacking. Each device passes a 25 micron carbon filament through the beam transversely at a constant velocity of 10 m/s. Collisions between the beam particles and the wire produce secondary particle cascades, which in turn produce photons in a scintillator. A photomultiplier tube is used to measure the light intensity while the wire position is determined by an optical encoder. There are six Accumulator flying wire systems. Four of them are to be used in normal stacking operation: two horizontal and two vertical flying wires are in the AP40 high dispersion section, covering the core orbit and the extraction orbit respectively. The other two horizontal wires are for measuring the momentum distribution of the beam on the central orbit at the Accumulator transition energy. At the AP40 high dispersion region a wire covers the central orbit, the other is in the AP30 low dispersion section. The operation and control of the flying wire system is discussed in this paper. 11 figs.
Date: April 23, 1990
Creator: Wang, X.Q.
Object Type: Report
System: The UNT Digital Library
Neoclassical effects on rf current drive (open access)

Neoclassical effects on rf current drive

A functional form is derived for the efficiency of current drive in toroidal geometry with low frequency waves (frequencies below the electron cyclotron frequency). By fitting constants in order to duplicate numerical results for the efficiency we obtain an accurate function which will be useful for computer calculations of current drive. 13 refs., 6 figs.
Date: April 1, 1990
Creator: Ehst, D.A. (Argonne National Lab., IL (USA). Fusion Power Program) & Karney, C.F.F. (Princeton Univ., NJ (USA). Plasma Physics Lab.)
Object Type: Report
System: The UNT Digital Library
The spatial evaluation of neighborhood clusters of birth defects (open access)

The spatial evaluation of neighborhood clusters of birth defects

Spatial statistics have recently been applied in epidemiology to evaluate clusters of cancer and birth defects. Their use requires a comparison population, drawn from the population at risk for disease, that may not always be readily available. In this dissertation the plausibility of using data on all birth defects, available from birth defects registries, as a surrogate for the spatial distribution of all live births in the analysis of clusters is assessed. Three spatial statistics that have been applied in epidemiologic investigations of clusters, nearest neighbor distance, average interpoint distance, and average distance to a fixed point, were evaluated by computer simulation for their properties in a unit square, and in a zip code region. Comparison of spatial distributions of live births and birth defects was performed by drawing samples of live births and birth defects from Santa Clara County, determining the street address at birth, geocoding this address and evaluating the resultant maps using various statistical techniques. The proposed method was then demonstrated on a previously confirmed cluster of oral cleft cases. All live births for the neighborhood were geocoded, as were all birth defects. Evaluation of this cluster using the nearest neighbor and average interpoint distance statistics was …
Date: April 16, 1990
Creator: Frisch, J. D.
Object Type: Report
System: The UNT Digital Library
Influence of collective effects on the performance of high-luminosity colliders (open access)

Influence of collective effects on the performance of high-luminosity colliders

The design of a high-luminosity electron-positron collider to study B physics is a challenging task from many points of view. In this paper we consider the influence of collective effects on the machine performance; most of our findings are generic,'' in the sense that they depend rather weakly on the details of the machine design. Both single-bunch and coupled-bunch instabilities are described and their effects are estimated based upon an example machine design (APIARY-IV). In addition, we examine the possibility of emittance growth from intrabeam scattering and calculate the beam lifetime from both Touschek and gas scattering. We find that the single-bunch instabilities should not lead to difficulty, and that the emittance growth is essentially negligible. At a background gas pressure of 10 nTorr, beam lifetimes of only a few hours are expected. Multibunch growth rates are very severe, even when using an optimized RF system consisting of single-cell, room-temperature RF cavities with geometrical shapes typical of superconducting cavities. Thus, a powerful feedback system will be required. In terms of collective effects, it does not appear
Date: April 1, 1990
Creator: Zisman, M. S.
Object Type: Article
System: The UNT Digital Library
Bench-scale reactor tests of low-temperature, catalytic gasification of wet, industrial wastes (open access)

Bench-scale reactor tests of low-temperature, catalytic gasification of wet, industrial wastes

Bench-scale reactor tests are under way at Pacific Northwest Laboratory to develop a low-temperature, catalytic gasification system. The system, licensed under the trade name Thermochemical Environmental Energy System (TEES{reg sign}), is designed for to a wide variety of feedstocks ranging from dilute organics in water to waste sludges from food processing. The current research program is focused on the use of a continuous-feed, tubular reactor. The catalyst is nickel metal on an inert support. Typical results show that feedstocks such as solutions of 2% para-cresol or 5% and 10% lactose in water or cheese whey can be processed to >99% reduction of chemical oxygen demand (COD) at a rate of up to 2 L/hr. The estimated residence time is less than 5 min at 360{degree}C and 3000 psig, not including 1 to 2 min required in the preheating zone of the reactor. The liquid hourly space velocity has been varied from 1.8 to 2.9 L feedstock/L catalyst/hr depending on the feedstock. The product fuel gas contains 40% to 55% methane, 35% to 50% carbon dioxide, and 5% to 10% hydrogen with as much as 2% ethane, but less than 0.1% ethylene or carbon monoxide, and small amounts of higher hydrocarbons. …
Date: April 1, 1990
Creator: Elliott, D. C.; Neuenschwander, G. G.; Baker, E. G.; Butner, R. S. & Sealock, L. J.
Object Type: Article
System: The UNT Digital Library
Software to support planning for future waste treatment, storage, transport, and disposal requirements (open access)

Software to support planning for future waste treatment, storage, transport, and disposal requirements

Planning for adequate and appropriate treatment, storage, transport and disposal of wastes to be generated or received in the future is a complex but critical task that can be significantly enhanced by the development and use of appropriate software. This paper describes a software system that has been developed at Pacific Northwest Laboratory to aid in such planning. The basic needs for such a system are outlined, and the approach adopted in developing the software is described. The individual components of the system, and their integration into a unified system, are discussed. Typical analytical applications of this type of software are summarized. Conclusions concerning the development of such software systems and the necessary supporting data are then presented. 2 figs.
Date: April 1, 1990
Creator: Holter, G. M.; Shay, M. R. & Stiles, D. L.
Object Type: Article
System: The UNT Digital Library
Collider Ring Particle Loss Tracking With SSCTRK (open access)

Collider Ring Particle Loss Tracking With SSCTRK

The SSCTRK numerical simulation tracking code has been used to study the benefit of increasing the SSC dipole magnet aperture from 4 to 5 cm. This study has been carried out for both hypothetical highly corrected and plausibly corrected machines, the former having no systematic multipole errors and chromaticity identically zero. The choice of tune values, phase advance per cell, random multipole errors, systematic multipole errors and chromaticity (for the plausibly corrected machines), closed orbit error, the criterion for particle loss, etc. are set forth in detail. Runs of 10{sup 5} turns and 3 {times} 10{sup 6} turns are presented together with the approximate dynamic apertures they yield from their particle loss patterns.
Date: April 1, 1990
Creator: Garavaglia, T.; Kauffmann, S. K. & Stiening, R.
Object Type: Article
System: The UNT Digital Library
Generative inspection process planner for integrated production (open access)

Generative inspection process planner for integrated production

This work describes the design prototype development of a generative process planning system for dimensional inspection. The system, IPPEX (Inspection Process Planning EXpert), is a rule-based expert system for integrated production. Using as advanced product modeler, relational databases, and artificial intelligence techniques, IPPEX generates the process plan and part program for the dimensional inspection of products using CMMs. Through an application interface, the IPPEX system software accesses product definition from the product modeler. The modeler is a solid geometric modeler coupled with a dimension and tolerance modeler. Resource data regarding the machines, probes, and fixtures are queried from databases. IPPEX represents inspection process knowledge as production rules and incorporates an embedded inference engine to perform decision making. The IPPEX system, its functional architecture, system architecture, system approach, product modeling environment, inspection features, inspection knowledge, hierarchical planning strategy, user interface formats, and other fundamental issues related to inspection planning and part programming for CMMs are described. 27 refs., 16 figs., 4 tabs.
Date: April 1, 1990
Creator: Brown, C.W. (Allied-Signal Aerospace Co., Kansas City, MO (USA). Kansas City Div.) & Gyorog, D.A. (Kansas Univ., Lawrence, KS (USA). Dept. of Mechanical Engineering)
Object Type: Article
System: The UNT Digital Library
Development of an advanced, continuous mild gasification process for the production of co-products (open access)

Development of an advanced, continuous mild gasification process for the production of co-products

A project team consisting of the Institute of Gas Technology, Peabody Holding Company, Inc., and Bechtel National, Inc., is developing a mild gasification process that uses a fluidized/entrained-bed reactor. This reactor is designed to process caking bituminous coals over a wide range of particle sizes without oxidative pretreatment, and also without the use of oxygen or air as reactants. The co-product streams, consisting of char, fuel gas, water, and condensables, would be separated by conventional means such as cyclone, staged condensers, and recycle-oil scrubbers. An isothermal process research unit (PRU) has been built at IGT, consisting of an 8-inch-I.D., 8-foot-long fluidized-bed section and a 4-inch-I.D., 13-foot-long entrained flow section, externally heated by electrical heaters. This quarter, eleven mild gasification tests were conducted in the PRU. Illinois No. 6 coal was used in nine of the tests and a West Virginia metallurgical grade of coal was used in the last two tests. The tests conducted in the PRU this quarter were operated with feed rates about three times higher than those used in the last quarter. Results show the effect of process temperature on the shields of char, oils/tars, and gases. Various compositional effects on the oils/tars were also discovered. Char …
Date: April 1, 1990
Creator: Knight, R. A.; Gissy, J.; Kline, S.; Onischak, M.; Babu, S. P. (Institute of Gas Technology, Chicago, IL (USA)) & Duthie, R. G. (Bechtel National, Inc., San Francisco, CA (USA))
Object Type: Report
System: The UNT Digital Library
Coupled transport processes in semipermeable media (open access)

Coupled transport processes in semipermeable media

A numerical simulator has been developed to investigate the effects of coupled processes on heat and mass transport in semipermeable media. The governing equations on which the simulator is based were derived using the thermodynamics of irreversible processes. The equations are nonlinear and have been solved numerically using the n-dimensional Newton's method. As an example of an application, the numerical simulator has been used to investigate heat and solute transport in the vicinity of a heat source buried in a saturated clay-like medium, in part to study solute transport in bentonite packing material surrounding a nuclear waste canister. The coupled processes considered were thermal filtration, thermal osmosis, chemical osmosis and ultrafiltration. In the simulations, heat transport by coupled processes was negligible compared to heat conduction, but pressure and solute migration were affected. Solute migration was retarded relative to the uncoupled case when only chemical osmosis was considered. When both chemical osmosis and thermal osmosis were included, solute migration was enhanced. 18 refs., 20 figs.
Date: April 1, 1990
Creator: Jacobsen, J.S. & Carnahan, C.L.
Object Type: Report
System: The UNT Digital Library
Hanford Site Waste Management and Environmental Restoration Integration Plan (open access)

Hanford Site Waste Management and Environmental Restoration Integration Plan

The Hanford Site Waste Management and Environmental Restoration Integration Plan'' describes major actions leading to waste disposal and site remediation. The primary purpose of this document is to provide a management tool for use by executives who need to quickly comprehend the waste management and environmental restoration programs. The Waste Management and Environmental Restoration Programs have been divided into missions. Waste Management consists of five missions: double-shell tank (DST) wastes; single-shell tank (SST) wastes (surveillance and interim storage, stabilization, and isolation); encapsulated cesium and strontium; solid wastes; and liquid effluents. Environmental Restoration consists of two missions: past practice units (PPU) (including characterization and assessment of SST wastes) and surplus facilities. For convenience, both aspects of SST wastes are discussed in one place. A general category of supporting activities is also included. 20 refs., 14 figs., 7 tabs.
Date: April 30, 1990
Creator: Merrick, D.L.
Object Type: Report
System: The UNT Digital Library
REMAP: A computer code that transfers node information between dissimilar grids (open access)

REMAP: A computer code that transfers node information between dissimilar grids

REMAP is a computer code that transfers the axisymmetric, two dimensional planar, or three dimensional temperature field from one finite element mesh to another. The meshes may be arbitrary as far as the number of elements and their geometry. REMAP interpolates or extrapolates the node temperatures from the old mesh to the new mesh using linear, bilinear, or trilinear isoparametric finite element shape functions. REMAP is used to transfer the temperature field from a thermal analysis mesh to a more finely discretized structural analysis mesh when performing a thermal stress analysis. REMAP was designed to be used with the finite element heat transfer codes TOPAZ2D and TOPAZ3D, and the solid mechanics codes NIKE2D and NIKE3D. The I/O formats in REMAP can be easily modified to accept input from other codes (e.g., finite difference) and generate output files for other structural codes. REMAP can be used to transfer any scalar field variable between dissimilar finite element meshes. The idea of a coarse filter by a fine filter to determine which element from the old mesh contains a node point from the new mesh was used. The coarse filter determines a subset of elements from the old mesh that may contain the …
Date: April 1, 1990
Creator: Shapiro, A. B.
Object Type: Report
System: The UNT Digital Library
(Experimental development, testing and research work in support of the inertial confinement fusion program) (open access)

(Experimental development, testing and research work in support of the inertial confinement fusion program)

This KMS Fusion Semi-Annual Technical Report covers the period October 1989 through March 1990. It contains a review of work performed by KMS Fusion, Inc. (KMSF), in support of the national program to achieve inertially confined fusion (ICF). A major section of the report is devoted to target technology, a field which is expected to play an increasingly important role in the overall KMSF fusion effort. Among the highlights of our efforts in this area covered in this report are: improvements and new developments in target fabrication techniques, including a discussion of techniques for introducing gaussian bumps and bands on target surfaces. Development of a single automated system for the interferometric characterization of transparent shells. Residual gas analysis of the blowing gases contained in glass shells made from xerogels. These usually include CO{sub 2}, O{sub 2} and N{sub 2}, and are objectionable because they dilute the fuel. Efforts to observe the ice layers formed in the {beta}-layering process in cryogenic targets, and to simulate the formation of these layers. In addition to our work on target technology, we conducted experiments with the Chroma laser and supported the ICF effort at other labs with theoretical and computational support as well as …
Date: April 27, 1990
Creator: Johnson, R.; Luckhardt, R.; Terry, N.; Drake, D. & Gaines, J. (eds.)
Object Type: Report
System: The UNT Digital Library
Combustion Dynamics Facility: April 1990 Workshop Working Group Reports (open access)

Combustion Dynamics Facility: April 1990 Workshop Working Group Reports

This document summarizes results from a workshop held April 5--7, 1990, on the proposed Combustion Dynamics Facility (CDF). The workshop was hosted by the Lawrence Berkeley Laboratory (LBL) and Sandia National Laboratories (SNL) to provide an opportunity for potential users to learn about the proposed experimental and computational facilities, to discuss the science that could be conducted with such facilities, and to offer suggestions as to how the specifications and design of the proposed facilities might be further refined to address the most visionary scientific opportunities. Some 130 chemical physicists, combustion chemists, and specialists in UV synchrotron radiation sources and free-electron lasers (more than half of whom were from institutions other than LBL and SNL) attended the five plenary sessions and participated in one or more of the nine parallel working group sessions. Seven of these sessions were devoted to broadening and strengthening the scope of CDF scientific opportunities and to detail the experimental facilities required to realize these opportunities. Two technical working group sessions addressed the design and proposed performance of two of the major CDF experimental facilities. These working groups and their chairpersons are listed below. A full listing of the attendees of the workshop is given in …
Date: April 1, 1990
Creator: Kung, A. H. & Lee, Y. T.
Object Type: Article
System: The UNT Digital Library
Interaction of cold-water aquifers with exploited reservoirs of the Cerro Prieto geothermal system (open access)

Interaction of cold-water aquifers with exploited reservoirs of the Cerro Prieto geothermal system

Cerro Prieto geothermal reservoirs tend to exhibit good hydraulic communication with adjacent cool groundwater aquifers. Under natural state conditions the hot fluids mix with the surrounding colder waters along the margins of the geothermal system, or discharge to shallow levels by flowing up fault L. In response to exploitation reservoir pressures decrease, leading to changes in the fluid flow pattern in the system and to groundwater influx. The various Cerro Prieto reservoirs have responded differently to production, showing localized near-well or generalized boiling, depending on their access to cool-water recharge. Significant cooling by dilution with groundwater has only been observed in wells located near the edges of the field. In general, entry of cool water at Cerro Prieto is beneficial because it tends to maintain reservoir pressures, restrict boiling, and lengthen the life and productivity of wells. 15 refs., 10 figs., 1 tab.
Date: April 1, 1990
Creator: Truesdell, A.H. (Geological Survey, Menlo Park, CA (USA)) & Lippmann, M.J. (Lawrence Berkeley Lab., CA (USA))
Object Type: Article
System: The UNT Digital Library
MGA (Multi-Group Analysis): A Gamma-Ray Spectrum Analysis Code for Determining Plutonium Isotopic Abundances (open access)

MGA (Multi-Group Analysis): A Gamma-Ray Spectrum Analysis Code for Determining Plutonium Isotopic Abundances

Nondestructive measurements of x-ray and gamma-ray emissions can be used to analyze a sample for plutonium. This report describes the methods and algorithms we have developed for analyzing gamma-ray spectra obtained by using a germanium detector system to accurately determine the relative abundances of various actinide isotopes in a sample. Our methodology requires no calibrations and can be used to measure virtually any size and type of plutonium sample. Measurement times can be as short as a few minutes; measurements are frequently accurate to within 1%. Our methods have been programmed into a computerized analysis code called MGA (Multi-Group Analysis). Our current versions can be run on personal computers (IBM type) and on the DEC VAX microcomputer. Spectral analysis times are usually far less than a minute. 28 refs., 26 figs., 1 tab.
Date: April 3, 1990
Creator: Gunnink, R
Object Type: Report
System: The UNT Digital Library
X-ray absorption spectroscopy: EXAFS (Extended X-ray Absorption Fine Structure) and XANES (X-ray Absorption Near Edge Structure) (open access)

X-ray absorption spectroscopy: EXAFS (Extended X-ray Absorption Fine Structure) and XANES (X-ray Absorption Near Edge Structure)

The x-ray absorption spectroscopy (XAS) had been an essential tool to gather spectroscopic information about atomic energy level structure in the early decades of this century. It has also played an important role in the discovery and systematization of rare-earth elements. The discovery of synchrotron radiation in 1952, and later the availability of broadly tunable synchrotron based x-ray sources have revitalized this technique since the 1970's. The correct interpretation of the oscillatory structure in the x-ray absorption cross-section above the absorption edge by Sayers et. al. has transformed XAS from a spectroscopic tool to a structural technique. EXAFS (Extended X-ray Absorption Fine Structure) yields information about the interatomic distances, near neighbor coordination numbers, and lattice dynamics. An excellent description of the principles and data analysis techniques of EXAFS is given by Teo. XANES (X-ray Absorption Near Edge Structure), on the other hand, gives information about the valence state, energy bandwidth and bond angles. Today, there are about 50 experimental stations in various synchrotrons around the world dedicated to collecting x-ray absorption data from the bulk and surfaces of solids and liquids. In this chapter, we will give the basic principles of XAS, explain the information content of essentially two different …
Date: April 1, 1990
Creator: Alp, E.E.; Mini, S.M. & Ramanathan, M.
Object Type: Article
System: The UNT Digital Library
Nonequilibrium molecular dynamics: Past, present, and future (open access)

Nonequilibrium molecular dynamics: Past, present, and future

This paper discusses the past, present and future of calculation methods in nonequilibrium molecular dynamics. (LSP)
Date: April 1, 1990
Creator: Hoover, W.G. (Keio Univ., Tokyo (Japan) California Univ., Davis, CA (USA) Lawrence Livermore National Lab., CA (USA))
Object Type: Article
System: The UNT Digital Library
Optimum catalytic process for alcohol fuels from syngas (open access)

Optimum catalytic process for alcohol fuels from syngas

The objectives of this contract are to discover and evaluate the catalytic properties of novel homogeneous, heterogeneous, or combination catalytic systems for the production of alcohol fuel extenders from syngas, to evaluate analytically and on the bench scale novel reactor concepts for use in converting syngas to liquid fuel products, and to develop on the bench scale the best combination of chemistry, reactor, and total process configuration to achieve the minimum product cost for conversion of syngas to liquid fuel products. Methanol production and heterogeneous catalysis utilizing transition elements supported on metal oxides with spinel structure are discussed. 12 figs., 16 tabs.
Date: April 28, 1990
Creator: unknown
Object Type: Report
System: The UNT Digital Library
U(1) prime dark matter and R-parity violation (open access)

U(1) prime dark matter and R-parity violation

Attempts to understand physics beyond the Standard Model must face many phenomenological constraint, from recent Z{sup {degree}} data, neutral current measurements, cosmology and astrophysics, neutrino experiments, tests of lepton-and baryon-number conservation and CP violation, and many other ongoing experiments. The most interesting models are those which are allowed by current data, but offer predictions which can soon be experimentally confirmed or refuted. Two classes of such models are explored in this dissertation. The first, containing an extra U(1){prime} gauge group, has a dark matter candidate which could soon be detected. The second, incorporating supersymmetry with R-parity violation, predicts rare Z{sup {degree}} decays at LEP; some of these models can already be ruled out by LEP data and gluino searches at the Tevatron. 54 refs., 31 figs.
Date: April 1, 1990
Creator: Brahm, D.E.
Object Type: Report
System: The UNT Digital Library
Methods of analysis for complex organic aerosol mixtures from urban emission sources of particulate carbon (open access)

Methods of analysis for complex organic aerosol mixtures from urban emission sources of particulate carbon

Extractable organic compounds having between 6 to 40 carbon atoms comprise an important mass fraction of the fine particulate matter samples from major urban emission sources. Depending on the emission source type, this solvent-soluble fraction accounts for <20% to 100% of the total organic aerosol mass, as measured by quantitative high-resolution has chromatography (HRGC) with flame ionization detection. In addition to total extract quantitation, HRGC can be applied to further analyses of the mass distributions of elutable organics present in the complex aerosol extract mixtures, thus generating profiles that serve as fingerprints'' for the sources of interest. This HRGC analytical method is applied to emission source samples that contain between 7 to 12,000 {mu}g/filter organic carbon. It is shown to be a sensitive technique for analysis of carbonaceous aerosol extract mixtures having diverse mass loadings and species distributions. This study describes the analytical chemical methods that have been applied to: the construction of chemical mass balances based on the mass of fine organic aerosol emitted for major urban sources of particulate carbon; and the generation of discrete emission source chemical profiles derived from chromatographic characteristics of the organic aerosol components. 21 refs., 1 fig., 2 tabs.
Date: April 1, 1990
Creator: Mazurek, M.A. (Brookhaven National Lab., Upton, NY (USA)); Hildemann, L.M. (Stanford Univ., CA (USA). Dept. of Civil Engineering); Cass, G.R.; Rogge, W.F. (California Inst. of Tech., Pasadena, CA (USA). Dept. of Environmental Engineering Science) & Simoneit, B.R.T. (Oregon State Univ., Corvallis, OR (USA). Coll. of Oceanography)
Object Type: Article
System: The UNT Digital Library