1,358 Matching Results

Search Results

Advanced search parameters have been applied.
in subjects: "Alkanes"  
prev Results: 25 - 48 next
open access

Abraham Solvation Parameter Model: Calculation of L Solute Descriptors for Large C11 to C42 Methylated Alkanes from Measured Gas–Liquid Chromatographic Retention Data

Description: This article determines Abraham model L solute descriptors for 149 additional C11 to C42 monomethylated and polymethylated alkanes based on published Kovat’s retention indices based upon gas–liquid chromatographic measurements.
Date: July 5, 2022
Creator: Wu, Emily; Sinha, Sneha; Yang, Chelsea; Zhang, Miles & Acree, William E. (William Eugene)
Item Type: Refine your search to only Article
Partner: UNT College of Science
open access

gem-Bis(disubstitutedphosphinyl)alkanes. II. Extraction Properties of Bis(di-n-hexlphosphinyl)methane

Description: From abstract: "Bis(di-n-hexylphosphinyl)methane, HDPM, [(C6H13)2P(O)]2CH2, has been studied as an extractant for a variety of metals. HDPM was evaluated as an extractant for uranium(VI) and compared with tri-n-octylphosphine oxide, TOPO, (C8H13)3PO. In nonpolar solvents, HDPM forms a polymeric-like substance with compounds of uranium(VI). Viscosity measurements indicate that the molecular weight of this polymeric-like substance is about 100 times greater than the corresponding complex with TOP… more
Date: April 11, 1961
Creator: Burke, Keith E.; Sakurai, Hiroshi; O'Laughlin, Jerome W. & Banks, Charles V.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The effects of pressure, temperature and concentration on the reactivity of alkanes; experiments and modeling in a rapid compression machine

Description: Experiments in a rapid compression machine have examined the influences of variations in pressure, temperature, and equivalence ratio on the autoignition of n-pentane. Equivalence ratios included values from 0.5 to � 2.0, compressed gas initial temperatures were varied between 675K and 980K, and compresed gas initial pressures varied from 8 to 20 bar. Numerical simulations of the same experiments were carried out using a detailed chemical kinetic reaction mechanism. The results are interpreted … more
Date: January 8, 1998
Creator: Curran, H J; Griffiths, J F; Mohamed, C; Pitz, W J; Westbrook, C & Wo, S K
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

SELECTIVITY IN ZEOLITE OCCLUSION OF OLEFINS

Description: Selective occlusions of straight-chain paraffins in the presence of branched-chain hydrocarbons by naturally occurring zeolites of suitable dimension was reported as early as 1944 by Barrer and Ibbitson. More recently the capacity of synthetic zeolites or molecular sieves to absorb exclusively the straight-chain hydrocarbons from complex hydrocarbon mixtures has found extensive application in the petroleum industry. Under the conditions developed for most sieving operations any normal olefins p… more
Date: August 30, 1966
Creator: Fenselau, Catherine & Calvin, Melvin
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Technology development for iron Fischer-Tropsch catalysts. Technical progress report No. 5, September 26, 1991--December 26, 1991

Description: Objective is to develop producing active, stable iron Fischer-Tropsch catalysts for use in slurry-phase synthesis reactors and to synthesize such catalysts on a large scale for process development and long-term testing in slurry bubble-column reactors. A mixed oxalate of Fe, Cu, and K was prepared; a catalyst will be prepared from this material. An evaluation run was performed on an Fe-based UCI catalyst, which was shown to produce low levels of C{sub 1} and C{sub 2} paraffins; e.g., at the end… more
Date: December 22, 1992
Creator: Frame, R. R. & Gala, H. B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

IUPAC-NIST Solubility Data Series. 98. Solubility of Polycyclic Aromatic Hydrocarbons in Pure and Organic Solvent Mixtures: Revised and Updated. Part 2. Ternary Solvent Mixtures

Description: Article on the solubility of polycyclic aromatic hydrocarbons in pure and organic solvent mixtures. This work updates volumes 54, 58, and 59 in the IUPAC Solubility Data Series and presents solubility data for polycyclic aromatic hydrocarbon solutes dissolved in ternary organic solvent mixtures.
Date: February 28, 2013
Creator: Acree, William E. (William Eugene)
Item Type: Refine your search to only Article
Partner: UNT College of Arts and Sciences
open access

Removal of chlorinated and non-chlorinated alkanes in a trickle-bed biofilter

Description: Increasing restrictions in emissions from a variety of industrial settings demand low cost removal of dilute contaminants in air. Many of these contaminants such as volatile organic components (VOCs) and sulfur compounds are biodegradable and can be removed from air streams via biofiltration. The simplest form of biofiltration consists of compost-based systems. More advanced systems designed for unique contaminants are biofilters with bioactive structured packing operating in trickle-bed mode. … more
Date: January 1, 1998
Creator: Klasson, K.T.; Davison, B.H.; Barton, J.W. & Jacobs, J.E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Analysis of Steam Heating of a Two-Layer TBP/N-Paraffin/Nitric Acid Mixtures

Description: This report presents an analysis of steam heating of a two-layer tri-n-butyl phosphate (TBP)/n-paraffin-nitric acid mixture.The purpose of this study is to determine if the degree of mixing provided by the steam jet or by bubbles generated by the TBP/nitric acid reaction is sufficient to prevent a runaway reaction.
Date: July 22, 1998
Creator: Laurinat, J. E.; Hassan, N. M.; Rudisill, T. S. & Askew, N. M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Dynamics of intermediate-length alkane films absorbed on graphite

Description: The dynamics of flexible chain molecules near a solid interface is of fundamental interest in polymer science. This paper makes a preliminary report on a quasielastic neutron scattering study of the dynamics of monolayer films of C{sub 24}H{sub 66} adsorbed on graphite. Quasielastic scattering was observed at temperatures as low as {approximately}180 K, well below the monolayer melting temperature of 340 K. Preliminary analysis of the data indicates that at 230 K the entire molecule executes a … more
Date: January 28, 2000
Creator: Herwig, K. W.; Fuhrmann, D.; Criswell, L.; Taub, H.; Hansen, F. Y.; Dimeo, R. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

{sup 17}O NMR Investigation of Oxidative Degradation in Polymers Under Gamma-Irradiation

Description: The {gamma}-irradiated-oxidation of pentacontane (C{sub 50}H{sub 102}) and the polymer polyisoprene was investigated as a function of oxidation level using {sup 17}O nuclear magnetic resonance (NMR) spectroscopy. It is demonstrated that by using {sup 17}O labeled O{sub 2} gas during the {gamma}-irradiation process, details about the oxidative degradation mechanisms can be directly obtained from the analysis of the {sup 17}O NMR spectra. Production of carboxylic acids is the primary oxygen-conta… more
Date: March 8, 2000
Creator: Alam, Todd M.; Celina, Mathias C.; Assink, Roger A.; Clough, Roger Lee & Gillen, Kenneth T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Gallium Zeolites for Light Paraffin Aromatization

Description: The primary original goal of this project was to investigate the active state of gallium-containing MFI catalysts for light paraffin aromatization, in particular the state of gallium in the active material. Our original hypothesis was that the most active and selective materials were those which contained gallium zeolitic cations, and that previously reported conditions for the activation of gallium-containing catalysts served to create these active centers. We believed that in high silica mate… more
Date: February 10, 1999
Creator: Price, G. L. & Dooley, K. M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Final Report for Grant DE-FG05-94ER14421 Period 11/1/2001-10/31/2002 Molecular Modeling and Simulation of Aqueous Electrolyte Systems

Description: Our proposal focused on the following research areas: (1) Development of intermolecular potentials for water and aqueous solutions; (2) Molecular-based study of polymorphic phase transitions and growth of nanocrystalline aggregates in hydrothermal solutions; (3) Molecular simulation of ion-pairing in high-temperature high-pressure electrolyte solutions; and (4) SAFT equation of state modeling of supercritical aqueous solutions - (a) Solubility of alkanes in supercritical water, and (b) Ion spec… more
Date: October 30, 2002
Creator: Cummings, Peter T. & McCabe, Clare
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Progress on Polarized Target Materials With Pure Carbon Background

Description: A previous note reviewed methods for the paramagnetic doping of materials for spin-polarized solid targets and some of the history of attempts to apply those methods to hydrocarbons. Since the earlier work on hydrocarbons had yielded, at best, rather mediocre results, that note also speculated on some ways to extend and, possibly, to improve upon the earlier work. The sharpest focus was on the light (number of carbons less than six) alkanes, since these are the hydrocarbons that have the highes… more
Date: March 24, 1993
Creator: Hill, D. A.; Crabb, D. G. & Krumpolc, M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Detailed structural characterization of the grafting of [Ta(=CHtBu)(CH2tBu)3] and [Cp*TaMe4] on silica partially dehydroxylated at 700 C and the activity of the grafted complexes toward alkane metathesis

Description: The reaction of [Ta({double_bond}CHtBu)(CH{sub 2}tBu){sub 3}] or [Cp*Ta(CH{sub 3}){sub 4}] with a silica partially dehydroxylated at 700 C gives the corresponding monosiloxy surface complexes [({triple_bond}SiO)Ta({double_bond}CHtBu)(CH{sub 2}tBu){sub 2}] and [({triple_bond}SiO)Ta(CH{sub 3}){sub 3}Cp*] by eliminating a {sigma}-bonded ligand as the corresponding alkane (H-CH{sub 2}tBu or H-CH{sub 3}). EXAFS data show that an adjacent siloxane bridge of the surface plays the role of an extra surf… more
Date: August 30, 2004
Creator: Le Roux, Erwan; Chabanas, Mathieu; Baudouin, Anne; de Mallmann, Aimery; Coperet, Christophe; Quadrelli, E. Allesandra et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

PHASE BEHAVIOR OF LIGHT GASES IN HYDROGEN AND AQUEOUS SOLVENTS

Description: Under previous support from the US Department of Energy, an experimental facility has been established and operated to measure valuable vapor-liquid equilibrium data for systems of interest in the production and processing of coal fluids. To facilitate the development and testing of models for prediction of the phase behavior for such systems, we have acquired substantial amounts of data on the equilibrium phase compositions for binary mixtures of heavy hydrocarbon solvents with a variety of su… more
Date: March 31, 1999
Creator: GASEM, KHALED A.M. & ROBERT L. ROBINSON, JR.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Nanorheology of Liquid Alkanes

Description: We report molecular dynamics simulations of liquid alkanes, squalane and tetracosane, confined between moving walls to which butane chains are tethered, effectively screening the details of the wall. As in an experiment, heat is removed by thermostatting the tethered molecules. Results obtained at high strain rates, typical of practical applications, suggest little or no difference between the bulk rheology and confined flow, and the occurrence of a high degree of slip at the wall-fluid interfa… more
Date: September 1, 1997
Creator: Gupta, S.A., Cochran, H.D., Cummings, P.T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Catalytic conversion of light alkanes phase II. Topical report, January 1990--January 1993

Description: The Topical Report on Phase II of the project entitled, Catalytic Conversion of Light Alkanes reviews work done between January 1, 1990 and September 30, 1992 on the Cooperative Agreement. The mission of this work is to devise a new catalyst which can be used in a simple economic process to convert the light alkanes in natural gas to oxygenate products which can either be used as clean-burning, high octane liquid fuels, as fuel components or as precursors to liquid hydrocarbon transportation fu… more
Date: December 31, 1998
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Deposition and Characterization of Highly Oriented Mg(3)(VO(4))(2) Thin Film Catalyst

Description: Magnesium vanadates are potentially important catalytic materials for the conversion of alkanes to alkenes via oxidative dehydrogenation. However, little is known about the active sites at which the catalytic reactions take place. It may be possible to obtain a significant increase in the catalytic efficiency if the effects of certain material properties on the surface reactions could be quantified and optimized through the use of appropriate preparation techniques. Given that surface reactivit… more
Date: October 22, 1999
Creator: Rodriguez, Mark A.; Ruffner, Judith A.; Sault, Allen G. & Tissot, Ralph G., Jr.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Catalytic conversion of light alkanes -- research and proof-of-concept stages

Description: Objective is to find new catalysts for direct reaction of methane, ethane, propane, butanes with O{sub 2} to form alcohols, and to develop practical processes for direct oxidative conversion of natural gas and its C{sub 1}-C{sub 4} components to produce alcohol-rich liquid oxygenates for use as alternative transportation fuels/environmentally superior reformulated gasolines. The proposed mechanism for oxidation activity of cytochrome P-450 and methane monoxygenase suggested that a catalyst able… more
Date: December 31, 1993
Creator: Lyons, J. E. & Hancock, A. W. II
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Development of Vanadium Phosphaate Catalysts for Methanol Production by Selective Oxidation of Methane.

Description: This DOE sponsored study of methane partial oxidation was initiated at Amax Research and Development in Golden, CO in October of 1993. Shortly thereafter the management of Amax closed this R&D facility and the PI moved to the Colorado School of Mines. The project was begun again after contract transfer via a novation agreement. Experimental work began with testing of vandyl pyrophosphate (VPO), a well known alkane selective oxidation catalyst. It was found that VPO was not a selective catalyst … more
Date: October 1, 1997
Creator: McCormick, R.L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Catalytic conversion of light alkanes: Proof of concept stage

Description: During the stage at which this work ended, our program consisted of two phases which were running concurrently, a research phase and a proof-of-concept phase. The function of the research phase is to design synthesize and perform laboratory tests on new materials in order to enhance the catalytic properties of the suprabiotic systems generated in our laboratories. Increases in catalytic activity and process selectivity as well as extensions of structure-activity relationships are examined. The … more
Date: June 1, 1995
Creator: Lyons, J.E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
Back to Top of Screen