288 Matching Results

Search Results

Advanced search parameters have been applied.

in subjects: "Formaldehyde"

open access

Variational transition state theory calculations of tunneling effects on concerted hydrogen motion in water clusters and formaldehyde/water clusters

The direct participation of water molecules in aqueous phase reaction processes has been postulated to occur via both single-step mechanisms as well as concerted hydrogen atom or proton shifts. In the present work, simple prototypes of concerted hydrogen atom transfer processes are examined for small hydrogen-bonded water clusters -- cyclic trimers and tetramers -- and hydrogen-bonded clusters of formaldehyde with one and two water molecules. Rate constants for the rearrangement processes are c… more

Date: August 1, 1990

Creator: Garrett, B.C. (Pacific Northwest Lab., Richland, WA (USA)) & Melius, C.F. (Sandia National Labs., Livermore, CA (USA))

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

High resolution transmission electron microscopy of melamine-formaldehyde aerogels and silica aerogels

The goal of the high resolution transmission electron microscopy (HRTEM) was to image the structure of two tetramethyl orthosilicate (TMOS) and two melamine-formaldehyde (MF) aerogels at the single polymer chain level{sup 1,2}. With this level of structural resolution we hoped to interrelate each aerogel's structure with its physical properties and its method of synthesis. Conventional single-step base catalysed TMOS aerogels show strings of spheroidal particles linked together with minimal nec… more

Date: September 1, 1991

Creator: Ruben, G.C. (Dartmouth Coll., Hanover, NH (United States). Dept. of Biological Sciences)

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Building ventilation and indoor air quality

Rising energy prices, among other factors, have generated an incentive to reduce ventilation rates and thereby reduce the cost of heating and cooling buildings. Reduced infiltration and ventilation in buildings may significantly increase exposure to indoor contaminants and perhaps have adverse effects on occupant health and comfort. Four indoor air contaminants - carbon monoxide and nitrogen dioxide from gas appliances; formaldehyde from particleboard, plywood, urea-formaldehyde foam insulation… more

Date: January 1, 1980

Creator: Hollowell, C. D.; Berk, J. V.; Boegel, M. L.; Miksch, R. R.; Nazaroff, W. W. & Traynor, G. W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Measurement of chemical emissions under the influence of low-NO{sub x} combustion modifications. Final report

Effect of low-NO{sub x} firing. There was no clear-cut effect on the emission of trace metals or acid gases. The data give marginal evidence for a decreased emission of Cr(VI), which would be a favorable change but is not certain by any means. The effect on aldehydes and ketones cannot be stated because of the loss of samples for baseline conditions; no credible data on these compounds were obtained for baseline conditions. The change in volatile organics appeared to be a reduction in emissions… more

Date: October 8, 1993

Creator: Dismukes, E. B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Classical and semiclassical aspects of chemical dynamics

Tunneling in the unimolecular reactions H/sub 2/C/sub 2/ ..-->.. HC/sub 2/H, HNC ..-->.. HCN, and H/sub 2/CO ..-->.. H/sub 2/ + CO is studied with a classical Hamiltonian that allows the reaction coordinate and transverse vibrational modes to be considered directly. A combination of classical perturbation theory and the semiclassical WKB method allows tunneling probabilities to be obtained, and a statistical theory (RRKM) is used to construct rate constants for these reactions in the tunneling … more

Date: August 1, 1982

Creator: Gray, Stephen Kevin

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Low Temperature Measurement of Thermal and Mechanical Properties of Phenolic Laminate, the Pultruded Polyester Fiberglass and A and B Epoxy Putty

Low temperature measurements were made and are reported of thermal and mechanical properties of phenolic laminate, pultruded polyester fiberglass, and A and B epoxy putty. To determine the modulus, compressive and tensile stress and strain, an Instron machine, a Tinus-Olsen testing machine, a Wheatstone bridge and strain gages were used. (FS)

Date: January 1, 1979

Creator: Wang, S. T.; Kim, S. H.; Kim, N. S.; Cheng, R. S.; Hoffman, J. & Gonczy, J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Exclusion-List Methodology for Weatherization Program in the Pacific Northwest

The Bonneville Power Administration (BPA) weatherization program includes measures that have the effect of reducing the ventilation rate in the structures in question, thereby not only saving energy but also increasing the potential for increased concentrations of indoor-generated airborne pollutants. In order to avoid having a significant impact on the health of occupants, certain classes of homes were excluded on the basis of house characteristics that may serve as indicators of higher-than-a… more

Date: May 1, 1982

Creator: Nero, A. V.; Turiel, I.; Fisk, W. J.; Cirman, J. R. & Traynor, C. W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Preparation and characterization of ligand types intermediate in the metal catalyzed conversion of coal to methane, methanol, and higher alkanes and alcohols. Second technical progress report, September 1, 1979-February 28, 1981

Mechanistic studies of anionic formyl complexes were made. The rate of decomposition of the formyl (CO)/sub 4/Mn(COC/sub 6/H/sub 5/)(CHO)/sup -/ anion as a function of counter-ion and trialkylborane present was examined. The deuterated formyl (CO)/sub 4/Mn(COC/sub 6/H/sub 5/)(CDO)/sup -/ was prepared and its decomposition was monitored by H/sup 2/ NMR. The data obtained indicate that the formyl decomposes by a disproportionative pathway not by initial CO loss, as commonly noted for formyl compl… more

Date: November 10, 1980

Creator: Gladysz, J. A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

(Selective carbon oxygen bond scission during reactions of oxygenates on single crystal catalysts)

We have discovered that the carbon-oxygen bond in methanol can be selectively broken if the surface structure of the platinum catalyst is appropriately tailored. The objective of this project is to determine if variations in surface structure allow one to selectively break C-O and C-H bonds. The decomposition of a wide range of oxygenates on several carefully chosen faces of group VIII metals will be examined to see when C-O bond scission occurs and what new chemistry we can find on stepped sur… more

Date: January 1, 1992

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Aerogels Derived From Multifunctional Organic Monomers

Traditional inorganic aerogels are mad via the hydrolysis and condensation of metal alkoxides. Recently, we reported the synthesis of organic aerogels based upon the aqueous polycondensation of (1) resorcinol with formaldehyde and (2) melamine with formaldehyde. The former materials can also be pyrolyzed in an inert atmosphere to form vitreous carbon aerogels. In both the inorganic and organic systems, the structure and properties of the dried aerogel are dictated by polymerization conditions. … more

Date: September 1, 1991

Creator: Pekala, R. W.; Alviso, C. T.; Kong, F. M. & Hulsey, S. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Model estimates of the contributions of environmental tobacco smoke to volatile organic compound exposures in office buildings

Volatile organic compounds (VOC) in office buildings originate from multiple sources, such as outdoor air, building materials, occupants, office supplies, and office equipment. Many of the VOC found in office buildings are also present in environmental tobacco smoke (ETS), e.g., benzene, toluene, formaldehyde. Measurements made to date in Office buildings have been interpreted by some to imply that the contributions to ETS to VOC exposures in office buildings are small. Four different ventilati… more

Date: January 1, 1990

Creator: Daisey, J. M.; Gadgil, A. & Hodgson, A. T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Survey of agents and techniques applicable to the solidification of low-level radioactive wastes

A review of the various solidification agents and techniques that are currently available or potentially applicable for the solidification of low-level radioactive wastes is presented. An overview of the types and quantities of low-level wastes produced is presented. Descriptions of waste form matrix materials, the wastes types for which they have been or may be applied and available information concerning relevant waste form properties and characteristics follow. Also included are descriptions… more

Date: December 1, 1981

Creator: Fuhrmann, M.; Neilson, R.M. Jr. & Colombo, P.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Environmental assessment in support of proposed voluntary energy conservation standard for new residential buildings

The objective of this environmental assessment (EA) is to identify the potential environmental impacts that could result from the proposed voluntary residential standard (VOLRES) on private sector construction of new residential buildings. 49 refs., 15 tabs.

Date: June 1, 1989

Creator: Hadley, D. L.; Parker, G. B.; Callaway, J. W.; Marsh, S. J.; Roop, J. M. & Taylor, Z. T.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Methane oxidation over dual redox catalysts

Catalytic oxidation of methane to partial oxidation products, primarily formaldehyde and C[sub 2] hydrocarbons, was found to be directed by the catalyst used. In this project, it was discovered that a moderate oxidative coupling catalyst for C[sub 2] hydrocarbons, zinc oxide, is modified by addition of small amounts of Cu and Fe dopants to yield fair yields of formaldehyde. A similar effect was observed with Cu/Sn/ZnO catalysts, and the presence of a redox Lewis acid, Fe[sup III] or Sn[sup IV],… more

Date: June 1, 1992

Creator: Klier, K.; Herman, R.G.; Sojka, Z.; DiCosimo, J.I. & DeTavernier, S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Indoor air quality measurements in 38 Pacific Northwest commercial buildings

A Bonneville Power Administration-funded study monitored ventilation rates and a variety of indoor air pollutants in 38 Pacific Northwest commercial buildings. The buildings ranged in age from 6 months to 90 years, in size from 864 to 34,280 m/sup 2/, and occupancy from 25 to 2500 people. Building average formaldehyde (HCHO) concentrations were below the 20 ppB detection limit in 48% of the buildings. Nitrogen dioxide (NO/sub 2/) concentration averages ranged from 5 ppB to 43 ppB and were lower… more

Date: June 1, 1986

Creator: Turk, B. H.; Brown, J. T.; Geisling-Sobotka, K.; Froehlich, D. A.; Grimsrud, D. T.; Harrison, J. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Indoor air quality. [Health hazards due to energy conservation measures]

Rising energy prices, among other factors, have generated an incentive to reduce ventilation rates and thereby reduce the cost of heating and cooling buildings. Reduced ventilation in buildings may significantly increase exposure to indoor air pollution and perhaps have adverse effects on occupant health and comfort. Preliminary findings suggest that reduced ventilation may adversely affect indoor air quality unless appropriate control strategies are undertaken. The strategies used to control i… more

Date: June 1, 1981

Creator: Hollowell, C. D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Health effects of risk-assessment categories

Environmental and occupational health effects associated with exposures to various chemicals are a subject of increasing concern. One recently developed methodology for assessing the health impacts of various chemical compounds involves the classification of similar chemicals into risk-assessment categories (RACs). This report reviews documented human health effects for a broad range of pollutants, classified by RACs. It complements other studies that have estimated human health effects by RAC … more

Date: October 1, 1983

Creator: Kramer, C. F.; Rybicka, K.; Knutson, A. & Morris, S. C.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Properties of radioactive wastes and waste containers. Quarterly progress report, January-March 1980

Solidification experiments were performed with organic ion-exchange resins using Portland type II cement to investigate waste to binder ratios which result in monolithic waste forms. Test results are provided in tabular form showing formulations which result in considerable swelling, cracking, or splitting of the specimens upon solidification. The range of waste loadings which produce monolithic waste forms is given. Experiments were conducted to establish appropriate waste/binder ratios within… more

Date: May 1, 1980

Creator: Manaktala, H.K. & Weiss, A.J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Fluid Diversion and Sweep Improvement with Chemical Gels in Oil Recovery Processes: Annual Report May 1, 1989 to April 30, 1990

The objectives of this project are to identify the mechanisms by which gel treatments divert fluids in reservoirs and to establish where and how gel treatments are best applied. Several different types of gelants are being examined. This research is directed at gel applications in water injection wells, in production wells, and in high-pressure gas floods. The work will establish how the flow properties of gels and gelling agents are influenced by permeability, lithology, and wettability. Other… more

Date: April 1, 1991

Creator: Seright, Frank S. & Martin, F. D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Evaluation of Wastewater Treatment Requirements for Thermochemical Biomass Liquefaction

Biomass can provide a substantial energy source. Liquids are preferred for use as transportation fuels because of their high energy density and handling ease and safety. Liquid fuel production from biomass can be accomplished by any of several different processes including hydrolysis and fermentation of the carbohydrates to alcohol fuels, thermal gasification and synthesis of alcohol or hydrocarbon fuels, direct extraction of biologically produced hydrocarbons such as seed oils or algae lipids,… more

Date: April 1, 1992

Creator: Elliott, D. C.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Quantitative mammalian cell genetic toxicology: study of the cytotoxicity and mutagenicity of 70 individual environmental agents related to energy technologies and 3 subfractions of a crude synthetic oil in the CHO/HGPRT system. [Hamsters]

Conditions necessary for quantifying mutation-induction to 6-thioguanine resistance, which selects for >98% mutants deficient in the activity of hypoxanthine-guanine phosphoribosyl transferase (HGPRT) in a near-diploid Chinese hamster ovary (CHO) cell line, referred to as CHO/HGPRT system, have been defined. Employing this mutation assay, we have determined the mutagenicity of diversified agents including 11 direct-acting alkylating agents, 16 nitrosamines, 10 heterocyclic nitrogen mustards,… more

Date: January 1, 1978

Creator: Hsie, A. W.; Neill, J. P. & San Sebastian, J. R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

State-of-the-art report on low-level radioactive waste treatment

An attempt is made to identify the main sources of low-level radioactive wastes that are generated in the United States. To place the waste problem in perspective, rough estimates are given of the annual amounts of each generic type of waste that is generated. Most of the wet solid wastes arise from the cleanup of gaseous and liquid radioactive streams prior to discharge or recycle. The treatment of the process streams and the secondary wet solid wastes thus generated is described for each type… more

Date: September 1, 1980

Creator: Kibbey, A. H. & Godbee, H. W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Millimeter and submillimeter wave absorption by atmospheric pollutants and constituents

Calculated absorption coefficients and rotational transition frequencies are given for a number of polar molecules of interest to pollution and energy research. The results, which are presented in graphical form for microwave frequencies up to 1400 GHz, illustrate the increased absorption line intensities occurring in the submillimeter region. For most species these absorption coefficients attain their maximum values in this region. Included in the calculations are the gases SO/sub 2/, H/sub 2/… more

Date: October 1, 1981

Creator: Kolbe, W.F. & Leskovar, B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Indoor air quality study of forty east Tennessee homes

Over a one-year period, measurements of indoor air pollutants (CO/sub x/, NO/sub x/, formaldehyde, volatile organics, particulates, and radon) were made in 40 homes in East Tennessee. The houses were of various ages with different types of insulation and heating. Over one-half of the houses exceeded the ASHRAE indoor ceiling guideline of 0.1 ppM for formaldehyde on at least one occasion. Over the duration of the study, older houses averaged 0.04 ppM of formaldehyde while houses less than 5 year… more

Date: December 1, 1984

Creator: Hawthorne, A. R.; Gammage, R. B.; Dudney, C. S.; Hingerty, B. E.; Schuresko, D. D.; Parzyck, D. C. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department