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Halogenated 2-Oxetanones

Description: The purpose of this investigation is threefold: (1) to examine in detail the cycloaddition of halogenated ketenes and carbonyl compounds, (2) to study the decarboxylation of the resulting halogenated 2-oxetanones,and (3) to investigate the effect of halogens in the halogenated 2-oxetanones on the nucleophilic addition reaction.
Date: May 1973
Creator: Patel, Arvind D.
Partner: UNT Libraries

Determination of Halogens in Organic Compounds by Using Sodium Fusion-Ion Chromatography Method

Description: A sodium fusion-Ion chromatographic method for determination of fluorine, chlorine, bromine, and iodine in organic compounds is described. Seventeen organic halogen compounds and eleven mixtures were decomposed by Na fumes at 280-290°C for one hour or longer. The absorbing solutions were injected for ion chromatographic analysis using electrochemical and conductometric detectors. The arrangement of the apparatus includes the placement of the electrochemical and conductometric detectors. This method provides a mechanism providing for complete analysis for all four halogens in one ion chromatographic sample injection. Reproducibility is excellent and liquid sample handling is mentioned.
Date: August 1983
Creator: Wang, Chung-Yu
Partner: UNT Libraries

Shock tube study of the reactions of the hydroxyl radical with combustion species and pollutants. Final report

Description: Shock heating t-butyl hydroperoxide behind a reflected shock wave has proved to be as a convenient source of hydroxyl radicals at temperatures near 1000 K. We applied this technique to the measurement of reaction rate coefficients of OH with several species of interest in combustion chemistry, and developed a thermochemical kinetics/transition state theory (TK-TST) model for predicting the temperature dependence of OH rate coefficients.
Date: February 1, 1998
Creator: Cohen, N. & Koffend, J.B.
Partner: UNT Libraries Government Documents Department

Determination of halogens in a petroleum product by ion chromatography

Description: A rapid, high-performance ion chromatography (HPIC) method with isocratic separation and the anion self-regenerating suppressor (in the chemical suppression mode, specifically for the determination of fluoride, chloride, bromide, and iodide in a petroleum product) is discussed. This is a proposed new method for a production laboratory within the Analytical Services Organization at the Oak Ridge Y-12 Plant.
Date: July 15, 1994
Creator: Tucker, H.L.
Partner: UNT Libraries Government Documents Department

Groundwater Monitoring Plan for the 216-A-29 Ditch

Description: This document presents a groundwater monitoring plan, under Resource Conservation and Recovery Act of 1976 (RCRA) regulatory requirements found in WAC 173-303-400, and by reference, requirements in 40 CFR 265.93 (d)(6) for the 216-A-29 Ditch (A-29 Ditch) in the Hanford Site's 200 East Area. The objectives of this monitoring plan are to determine whether any hazardous constituents are detectable in the groundwater beneath the ditch. The groundwater monitoring network described in this plan includes 10 RCRA-compliant wells to monitor the aquifer in the immediate vicinity of the A-29 Ditch. Groundwater assessment activities have been conducted at the A-29 Ditch, the result of elevated specific conductivity and total organic halogens (TOX). A groundwater assessment report (Votava 1995) found that no hazardous constituents had impacted groundwater and the site returned to interim-status indicator-parameter/detection monitoring. This plan describes the process and quality objectives for conducting the indicator-parameter program. The site will be sampled semiannually for indicator parameters including pH, specific conductance, TOX, and total organic carbon. Site-specific parameters include tritium and ICP metals. These constituents, as well as anions, alkalinity, and turbidity will be sampled annually. Groundwater elevations will be recorded semiannually.
Date: October 7, 1999
Creator: Sweeney, M.D.
Partner: UNT Libraries Government Documents Department

Novel Fluorine-Containing NMDA Antagonists for Brain Imaging: In Vitro Evaluation

Description: The NMDA receptor has been implicated in neuronal death following stroke, brain injury and neurodegenerative disorders (e.g. Alzheimer's, Parkinson's and Huntington's disease) and in physiological functions (e.g. memory and cognition). Non-competitive antagonists, such as MK- 801 and CNS-1102, that block the action of glutamate at the NMDA receptor have been shown to be neuroprotective by blocking the influx of calcium into the cells. As a result, they are being considered as therapeutic agents for the above mentioned diseases. Several Fluorine-containing novel analogs of NMDA channel blockers have been synthesized and evaluated in search of a compound suitable for 18F labeling and Positron Emission Tomography (PET). Based on in vitro binding assay studies on rat brain membranes, the novel compounds examined displayed a range of affinities. Preliminary analyses indicated that chlorine is the best halogen on the ring, and that ethyl fluoro derivatives are more potent than methyl-fluoro compounds. Further analysis based on autoradiography will be needed to examine the regional binding characteristics of the novel compounds examined in this study. Labeling with 18F will allow the use of these compounds in humans, generating new insights into mechanisms and treatment of diseases involving malfunction of the glutamatergic system in the brain.
Date: January 1, 2001
Creator: Alvarado, M. & Biegon, A.
Partner: UNT Libraries Government Documents Department

Highly Efficient Small Form Factor LED Retrofit Lamp

Description: This report summarizes work to develop a high efficiency LED-based MR16 lamp downlight at OSRAM SYLVANIA under US Department of Energy contract DE-EE0000611. A new multichip LED package, electronic driver, and reflector optic were developed for these lamps. At steady-state, the lamp luminous flux was 409 lumens (lm), luminous efficacy of 87 lumens per watt (LPW), CRI (Ra) of 87, and R9 of 85 at a correlated color temperature (CCT) of 3285K. The LED alone achieved 120 lumens per watt efficacy and 600 lumen flux output at 25 C. The driver had 90% electrical conversion efficiency while maintaining excellent power quality with power factor >0.90 at a power of only 5 watts. Compared to similar existing MR16 lamps using LED sources, these lamps had much higher efficacy and color quality. The objective of this work was to demonstrate a LED-based MR16 retrofit lamp for replacement of 35W halogen MR16 lamps having (1) luminous flux of 500 lumens, (2) luminous efficacy of 100 lumens per watt, (3) beam angle less than 40{sup o} and center beam candlepower of at least 1000 candelas, and (4) excellent color quality.
Date: September 11, 2011
Creator: Allen, Steven; Palmer, Fred & Li, Ming
Partner: UNT Libraries Government Documents Department

Discovery, SAR, and Radiolabeling of Halogenated Benzimidazole Carboxamide Antagonists as Useful Tools for (alpha)4(beta)1 Integrin Expressed on T- and B-cell Lymphomas

Description: The cell surface receptor {alpha}{sub 4}{beta}{sub 1} integrin is an attractive yet poorly understood target for selective diagnosis and treatment of T- and B-cell lymphomas. This report focuses on the rapid microwave preparation of medicinally pertinent benzimidazole heterocycles, structure-activity relationships (SAR) of novel halobenzimidazole carboxamide antagonists 3-6, and preliminary biological evaluation of radioiodinated agents 7, 8, and 18. The I-125 derivative 18 had good tumor uptake (12 {+-} 1% ID/g at 24 h; 4.5 {+-} 1% ID/g at 48 h) and tumor:kidney ratio ({approx}4:1 at 24 h; 2.5:1 at 48 h) in xenograft murine models of B-cell lymphoma. Molecular homology models of {alpha}{sub 4}{beta}{sub 1} integrin have predicted that docked halobenzimidazole carboxamides have the halogen atom in a suitable orientation for halogen-hydrogen bonding. These high affinity ({approx} pM binding) halogenated ligands are attractive tools for medicinal and biological use; the fluoro and iodo derivatives are potential radiodiagnostic ({sup 18}F) or radiotherapeutic ({sup 131}I) agents, whereas the chloro and bromo analogues could provide structural insight into integrin-ligand interactions through photoaffinity cross-linking/mass spectroscopy experiments, as well as co-crystallization X-ray studies.
Date: February 8, 2010
Creator: Carpenter, R D; Natarajan, A; Lau, E Y; Andrei, M; Solano, D M; Lightstone, F C et al.
Partner: UNT Libraries Government Documents Department

ACCIDENT IN CONTINUOUS-DISSOLVER PILOT PLANT OF FLUORIDE VOLATILITY PROJECT ON MAY 15, 1957

Description: A series of explosions, estimated at five, occurred over a period of ten seconds within the continuous dissolver pilot plant, of the Fluoride Volatility Project on May 15, 1957. The explosive reactions occurred in the dissolver vessels as a result of violent chemical reactions between uranium and an interhalogen mixture. Just what the conditions were which triggered the explosions, have not been definitely established. Nevertheless, based upon the evidence which has been collected, several possible explanations, listed according to probability, are presented. A number of recommendations are included to be followed before operation of the pilot plant is resumed. These recommendations relate to additional laboratory research, equipment design, facility design, and use of a review committee. Safety rules for handling BrF/ sub 3/, BrF/sub 5/, ClF/sub 3/, and Br/sub 2/ are appended. (C.H.)
Date: July 10, 1957
Creator: Strickland, G.; Horn, F.L.; Johnson, R. & Dwyer, O.E.
Partner: UNT Libraries Government Documents Department

The chemistry of halogens on diamond: effects on growth and electron emission

Description: Diamond growth using halogenated precursors was studied in several diamond growth reactors. In a conventionao plasma reactor, diamond growth using the following gas mixtures was studied: CF{sub 4}/H{sub 2}, CH{sub 4}/H{sub 2}, CH{sub 3}F/H{sub 2}, and CH{sub 3}CL/H{sub 2}. Both the diamond growth measurements demonstrated ineffective transport of halogen radicals to the diamond surface during the growth process. In order to transport radical halogen species to the diamond surface during growth, a flow-tube reactor was constructed which minimized gas phase reactions. Also, the flow-tube reactor enabled pulsed gs transport to the diamond surface by fast-acting valves. Molecular beam mass spectroscopy was used to find condition which resulted in atomic hydrogen and/or atomic fluorine transport to the growing diamond surface. Although such conditions were found, they required very low pressures (0.5 Torr and below); these low pressures produce radical fluxes which are too low to sustain a reasonable diamond growth rate. The sequential reactor at Stanford was modified to add a halogen-growth step to the conventinoal atomic hydrogen/atomic carbon diamond growth cycle. Since the atomic fluorine, hydrogen and carbon environments are independent in the sequential reactor, the effect of fluorine on diamond growth could be studied independently of gas phase reactions. Although the diamond growth rate was increased by the use of fluorine, the film quality was seen to deteriorate as well as the substrate surface. Moreover, materials incompatibilities with fluorine significantly limited the use of fluorine in this reactor. A diamond growth model incorporating both gas phase and surface reactions was developed for the halocarbon system concurrent with the film growth efforts. In this report, we review the results of the growth experiments, the modeling, and additional experiments done to understand fluorine with diamond surfaces.
Date: February 1, 1997
Creator: Hsu, W.L.; Pan, L.S. & Brown, L.A.
Partner: UNT Libraries Government Documents Department

Determination of halogen content in glass for assessment of melter decontamination factors

Description: Melter decontamination factor (DF) values for the halogens (fluorine, chlorine, and iodine) are important to the Hanford Waste Vitrification Plant (HWVP) process because of the potential influence of DF on secondary-waste recycle strategies (fluorine and chlorine) as well as its impact on off-gas emissions (iodine). This study directly establishes the concentrations of halides-in HWVP simulated reference glasses rather than relying on indirect off-gas data. For fluorine and chlorine, pyrohydrolysis coupled with halide (ion chromatographic) detection has proven to be a useful analytical approach suitable for glass matrices, sensitive enough for the range of halogens encountered, and compatible with remote process support applications. Results obtained from pyrohydrolytic analysis of pilot-scale ceramic melter (PSCM) -22 and -23 glasses indicate that the processing behavior of fluorine and chlorine is quite variable even under similar processing conditions. Specifically, PSCM-23 glass exhibited a {approximately}90% halogen (F and Cl) retention efficiency, while only 20% was incorporated in PSCM-22 glass. These two sets of very dissimilar test results clearly do not form a sufficient basis for establishing design DF values for fluorine and chlorine. Because the present data do not provide any new halogen volatility information, but instead reconfirm the validity of previously obtained offgas derived values, melter DF values of 4, 2, and 1 for fluorine, chlorine, and iodine, respectively, are recommended for adoption; these values were conservatively established by a team of responsible engineers at Westinghouse Hanford Company (WHC) and Pacific Northwest Laboratory (PNL) on the basis of average behavior for many comparable melter tests. In the absence of further HWVP process data, these average melter DFs are the best values currently available.
Date: March 1, 1996
Creator: Goles, R.W.
Partner: UNT Libraries Government Documents Department

EDDY RESOLVING NUTRIENT ECODYNAMICS IN THE GLOBAL PARALLEL OCEAN PROGRAM AND CONNECTIONS WITH TRACE GASES IN THE SULFUR, HALOGEN AND NMHC CYCLES

Description: Ecodynamics and the sea-air transfer of climate relevant trace gases are intimately coupled in the oceanic mixed layer. Ventilation of species such as dimethyl sulfide and methyl bromide constitutes a key linkage within the earth system. We are creating a research tool for the study of marine trace gas distributions by implementing coupled ecology-gas chemistry in the high resolution Parallel Ocean Program (POP). The fundamental circulation model is eddy resolving, with cell sizes averaging 0.15 degree (lat/long). Here we describe ecochemistry integration. Density dependent mortality and iron geochemistry have enhanced agreement with chlorophyll measurements. Indications are that dimethyl sulfide production rates must be adjusted for latitude dependence to match recent compilations. This may reflect the need for phytoplankton to conserve nitrogen by favoring sulfurous osmolytes. Global simulations are also available for carbonyl sulfide, the methyl halides and for nonmethane hydrocarbons. We discuss future applications including interaction with atmospheric chemistry models, high resolution biogeochemical snapshots and the study of open ocean fertilization.
Date: August 1, 2000
Creator: CHU, S. & ELLIOTT, S.
Partner: UNT Libraries Government Documents Department

Proof-of-concept experiments for negative ion driver beams forheavy ion fusion

Description: Negative halogen ion beams have recently been proposed as heavy ion fusion drivers. They would avoid the problem of electron accumulation in positive ion beams, and could be efficiently photodetached to neutrals if desired [1]. Initial experiments using chlorine produced a current density of 45 mA/cm{sup 2} of 99.5% atomic negative Cl with an e/Cl{sup -} ratio as low as 7:1 and good emittance.
Date: May 13, 2003
Creator: Grisham, L.R.; Hahto, S.K.; Hahto, S.T.; Kwan, J.W. & Leung, K.N.
Partner: UNT Libraries Government Documents Department

Final Report, "Laboratory Studies of the Role of Sea Salt Bromine in Determining Tropospheric Ozone"

Description: This document is a final report for the project DE-FG03-98ER62578, "Laboratory Studies of the Role of Sea Salt Bromine in Determining Tropospheric Ozone". It includes a technical summary, collaborations, educational contributions and the peer-reviewed scientific publications that have resulted from this research.
Date: June 20, 2005
Creator: Finlayson-Pitts, B. J.
Partner: UNT Libraries Government Documents Department

Nevada Test Site 2001 Data Report: Groundwater Monitoring Program Area 5 Radioactive Waste Management Site

Description: This report is a compilation of the calendar year 2001 groundwater sampling results from the Area 5 Radioactive Waste Management Site (RWMS). Contamination indicator data are presented in control chart and tabular form with investigation levels (ILs) indicated. Gross water chemistry data are presented in graphical and tabular form. Other information in the report includes, the Cumulative Chronology for Area 5 RWMS Groundwater Monitoring Program, a brief description of the site hydrogeology, and the groundwater sampling procedure. Wells Ue5PW-1, Ue5PW-2, and Ue5PW-3 were sampled semiannually for the required analytes: pH, specific conductance, major cations/anions, metals, tritium, total organic carbon (TOC), and total organic halogen (TOX). Due to detections of TOC and TOX in some samples collected in 2000, a plan, as approved by the Nevada Division of Environmental Protection (NDEP), was executed to collect an increased number and type of samples in 2001. Results from all samples collected in 2001 were below ILs. These data indicate that there has been no measurable impact to the uppermost aquifer from the Resource Conservation and Recovery Act (RCRA) regulated unit within the Area 5 RWMS and confirm that the detections of TOC and TOX in 2000 were false positives. There were no major changes noted in the monitored groundwater elevation. There continues to be an extremely small gradient to the northeast with an average flow velocity of less than one foot per year.
Date: February 1, 2002
Creator: Townsend, Y. E.
Partner: UNT Libraries Government Documents Department

THE DYNAMICS OF HYDROGEN ATOM ABSTRACTION FROM POLYATOMIC MOLECULES.

Description: The hydrogen atom abstraction reaction is an important fundamental process that is extensively involved in atmospheric and combustion chemistry. The practical significance of this type of reaction with polyatomic hydrocarbons is manifest, which has led to many kinetics studies. The detailed understanding of these reactions requires corresponding dynamics studies. However, in comparison to the A + HX {radical} AH + X reactions, the study of the dynamics of A + HR {yields} AH + R reactions is much more difficult, both experimentally and theoretically (here and in the following, A stands for an atom, X stands for a halogen atom, and R stands for a polyatomic hydrocarbon radical). The complication stems from the structured R, in contrast to the structureless X. First of all, there are many internal degrees of freedom in R that can participate in the reaction. In addition, there are different carbon sites from which an H atom can be abstracted, and the dynamics are correspondingly different; there are also multiple identical carbon sites in HR and in the picture of a local reaction, there exist competitions between neighboring H atoms, and so on. Despite this complexity, there have been continuing efforts to obtain insight into the dynamics of these reactions. In this chapter, some examples are presented, including the reactions of ground state H, Cl, and O atoms, with particular focus on our recent work using imaging to obtain the differential cross sections for these reactions.
Date: November 21, 2002
Creator: Liu, X. & Suits, A. G.
Partner: UNT Libraries Government Documents Department

HALOGEN COLLECTOR TEST PROGRAM

Description: Efficiency tests of removal of radioactive iodine from an air stream were performed on the following halogen collectors: a silver-plated copper-ribbon bed: activatedcharcoal beds, 0.5 and l.0 in. deep: a molecular-sieve bed; and a sodium thiosulfate bed. The tests were conducted at 70 and 160 deg F and at 70 and 95% relative humidity. Only the activated-charcoal collectors achieved a high iodineremoval efficiency over a sustained period at the various operating conditions. (C.J.G.)
Date: March 1, 1960
Partner: UNT Libraries Government Documents Department

FIELD SCREENING FOR HALOGENATED VOLATILE ORGANIC COMPOUNDS: THE NEW X-WAND HVOC SCREENING DEVICE

Description: Western Research Institute (WRI) has developed new methodology and a test kit to screen soil or water samples for halogenated volatile organic compounds (HVOCs) in the field. The technology has been designated the X-Wand{trademark} screening tool. The new device uses a heated diode sensor that is commonly used to detect leaks of refrigerants from air conditioners, freezers, and refrigerators. This sensor is selective to halogens. It does not respond to volatile aromatic hydrocarbons, such as those in gasoline, and it is not affected by high humidity. In the current work, the heated diode leak detectors were modified further to provide units with rapid response and enhanced sensitivity. The limit of detection for trichloroethylene TCE in air is 0.1 mg/m{sup 3} (S/N = 2). The response to other HVOCS relative to TCE is similar. Variability between sensors and changes in a particular sensor over time can be compensated for by normalizing sensor readings to a maximum sensor reading at 1,000 mg/m{sup 3} TCE. The soil TCE screening method was expanded to include application to water samples. Assuming complete vaporization, the detection limit for TCE in soil is about 1 ug/kg (ppb) for a 25-g sample in an 8-oz jar. The detection limit for TCE in water is about 1 ug/L (ppb) for a 25-mL sample in an 8-oz jar. This is comparable to quantitation limits of EPA GC/MS laboratory methods. A draft ASTM method for screening TCE contaminated soils using a heated diode sensor was successfully submitted for concurrent main committee and subcommittee balloting in ASTM Committee D 34 on Waste Management. The method was approved as ASTM D 7203-05, Standard Test Method for Screening Trichloroethylene (TCE)-Contaminated Soil Using a Heated Diode Sensor.
Date: March 1, 2006
Creator: Schabron, John F.; Sorini, Susan S. & Jr, Joseph F. Rovani
Partner: UNT Libraries Government Documents Department

Mechanism of the Initial Oxidation of Hydrogen andHalogen Terminated Ge(111) Surfaces in Air

Description: The initial stage of the oxidation of Ge(111) surfaces etched by HF, HCl and HBr solutions is systematically studied using synchrotron radiation photoelectron spectroscopy (SR-PES). We perform controlled experiments to differentiate the effects of different oxidation factors. SR-PES results show that both moisture and oxygen contribute to the oxidation of the surfaces; however, they play different roles in the oxidation process. Moisture effectively replaces the hydrogen and halogen termination layers with hydroxyl (OH), but hardly oxidizes the surfaces further. On the other hand, dry oxygen does not replace the termination layers, but breaks the Ge-Ge back bonds and oxidizes the substrates with the aid of moisture. In addition, room light enhances the oxidation rate significantly.
Date: August 23, 2006
Creator: Sun, Shiyu; /Stanford U., Phys. Dept.; Sun, Yun; Liu, Zhi; Lee, Dong-Ick; Pianetta, Piero et al.
Partner: UNT Libraries Government Documents Department