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in subjects: "Molecular Weight"

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Additional Reserve Recovery Using New Polymer Treatment on High Water Oil Ratio Wells in Alameda Field, Kingman County, Kansas

The Chemical Flooding process, like a polymer treatment, as a tertiary (enhanced) oil recovery process can be a very good solution based on the condition of this field and its low cost compared to the drilling of new wells. It is an improved water flooding method in which high molecular-weight (macro-size molecules) and water-soluble polymers are added to the injection water to improve the mobility ratio by enhancing the viscosity of the water and by reducing permeability in invaded zones durin… more

Date: October 1, 2005

Creator: Spillane, James

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Degradation kinetics of polymers in solution: Time-dependence of molecular weight distributions. [Quarterly report, January--March 1996]

Polymer degradation occurs when polymer chains are broken under the influence of thermal, mechanical, or chemical energy. Chain-end depolymerization and random- and midpoint-chain scission are mechanisms that have been observed in liquid-phase polymer degradation. Here we develop mathematical models, unified by continuous-mixture kinetics, to show how these different mechanisms affect polymer degradation in solution. Rate expressions for the fragmentation of molecular-weight distributions (MWDs… more

Date: February 27, 1996

Creator: McCoy, B.J. & Madras, G.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Opto-acoustic cell permeation

Optically generated acoustic waves have been used to temporarily permeate biological cells. This technique may be useful for enhancing transfection of DNA into cells or enhancing the absorption of locally delivered drugs. A diode-pumped frequency-doubled Nd:YAG laser operating at kHz repetition rates was used to produce a series of acoustic pulses. An acoustic wave was formed via thermoelastic expansion by depositing laser radiation into an absorbing dye. Generated pressures were measured with … more

Date: March 9, 2000

Creator: Visuri, S R & Heredia, N

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Dynamics of Polymers at Interfaces

This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This project addresses fundamental questions concerning the behavior of polymers at interfaces: (1) What processes control the formation of an adsorbed layer on a clean surface? (2) What processes control the displacement of preadsorbed polymers? (3) Can one accurately predict the structure of polymer layers? To answer these questions, using neutron… more

Date: November 1, 1999

Creator: Smith, G. S.; Majewski, J. & Al, Et

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Hydrolytic Degradation of Estane 5703

Relative to the unaged Estane{reg_sign} 5703, heating decreases the modulus and ultimate stress for both the dry and humid samples. The sample aged in dry air, quickly recovered to its original mechanical properties. The reversibility of the mechanical properties is a result of the reorganization of the hard segments into domains. For the Estane 5703 samples aged in humid air, the mechanical properties only partially recovered with time. Molecular weight data confirm that differences in the ext… more

Date: April 27, 1999

Creator: Wrobleski, D.A.; Smith, M.E. & Orler, E.B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Factor analysis of GPC-FTIR data in PBX9501 binder degradation studies

The GPC/FTIR data consist of sets of 120 FTIR spectra corresponding to 120 GPC fractions. The GPC fractions can be further categorized by their polystyrene equivalent molecular weight and retention time, The FTIR data to be compared is in three sets of 120 spectra corresponding to the control, thermally aged, and radiolytically aged binder material. Figure 1 shows the extracted spectra (or factors) and corresponding concentration profiles (or scores) for the control data set. The four extracted… more

Date: November 1, 2000

Creator: Schoonover, J. & Bridgewater, J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

PETROLEUM RESIDUA SOLUBILITY PARAMETER/POLARITY MAP: STABILITY STUDIES OF RESIDUA PYROLYSIS

A new molecular weight/polarity map based on the Scatchard-Hildebrand solubility equation has been developed for petroleum residua. A series of extractions are performed with solvents of increasing solubility parameter, and the fractions are analyzed by vapor pressure osmometry for number average molecular weight and by analytical-scale size exclusion chromatography for molecular weight spread. Work was performed for a heavy oil material subjected to three increasing severities of thermal treat… more

Date: April 30, 1999

Creator: Schabron, John F.; Pauli, A. Troy & Joseph F. Rovani, Jr.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Modeling Emissions of Volatile Organic Compounds from New Carpets

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.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

EFFECTS OF TRITIUM ON UHMW-PE, PTFE, AND VESPEL POLYIMIDE

Samples of ultrahigh molecular weight polyethylene (UHMW-PE), polytetrafluoroethylene (PTFE), and the polyimide Vespel{reg_sign} were exposed to tritium gas in closed containers initially at 101 kPa (1 atmosphere) pressure and ambient temperature for various times up to 2.3 years. Tritium exposure effects on the samples were characterized by dynamic mechanical analysis (DMA) and radiolysis products were characterized by measuring the total final pressure and composition in the exposure containe… more

Date: November 1, 2006

Creator: Clark, E & Kirk Shanahan, K

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

A Mechanistic Investigation of Gelation. The Sol-Gel Polymerization of Bridged Silsesquioxane Monomers

The study of a homologous series of silsesquioxane monomers has uncovered striking discontinuities in gelation behavior. An investigation of the chemistry during the early stages of the polymerization has provided a molecular basis for these observations. Monomers containing from one to four carbon atoms exhibit a pronounced tendency to undergo inter or intramolecular cyclization. The cyclic intermediates have been characterized by {sup 29}Si NMR, chemical ionization mass spectrometry and isola… more

Date: July 14, 2000

Creator: SHEA,KENNETH J. & LOY,DOUGLAS A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Detection of Biological Materials Using Ion Mobility Spectroscopy

Traditionally, Ion Mobility Spectroscopy has been used to examine ions of relatively low molecular weight and high ion mobility. In recent years, however, biomolecules such as bradykinin, cytochrome c, bovine pancreatic trypsin inhibitor (BPTI), apomyoglobin, and lysozyme, have been successfully analyzed, but studies of whole bio-organisms have not been performed. In this study an attempt was made to detect and measure the mobility of two bacteriophages, {lambda}-phage and MS2 using electrospra… more

Date: March 1, 1999

Creator: Rodacy, P. J.; Sterling, J. P. & Butler, M. A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Solution Behavior of Modified Polyethylenimine (PEI) Polymers by Light Scattering Investigations

The eight average molecular weights, as well as other characteristics such as the second virial coefficients and root-mean-square (RMS) radii of gyration of poly (ethyleneimine) (PEI) and various derivatives, have been determined in solution light scattering studies. The solution dynamics of PEI and carboxylated and phosphorylated derivatives were studied a pH of 3.3, 7.0 and 10.0. Measurements were made in freshly distilled and de-ionized water as well as in 0.1 M, 1 M and 5-M solutions of sod… more

Date: March 18, 2004

Creator: Ekhorutomwen, Sonny A.; Sawan, Samuel P.; Smith, Barbara F.; Robison, Thomas W. & Wilson, Kennard V.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Stimuli-Responsive Polymers with Enhanced Efficiency in Reservoir Recovery Processes

This sixth and final progress report for DOE Award Number DE-FC26-01BC15317 describes research during the period March 01, 2004 through August 31, 2004 performed at the University of Southern Mississippi on ''Stimuli Responsive Polymers with Enhanced Efficiency in Reservoir Recovery'' processes. Significantly, terpolymers that are responsive to changes in pH and ionic strength have been synthesized, characterized, and their solution properties have been extensively examined. Terpolymers compose… more

Date: September 30, 2004

Creator: McCormick, Charles & Hester, Roger

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Effects of 108 Days Tritium Exposure on UHMW-PE, PTFE, and Vespel(R)

Samples of three polymers, Ultra-High Molecular Weight Polyethylene (UHMW-PE), polytetrafluoroethylene (PTFE), also known as Teflon(R), and Vespel(R) polyimide were exposed to 1 atmosphere of tritium gas at ambient temperature for 108 days. Sample mass and size measurements to calculate density, spectra-colorimetry, dynamic mechanical analysis (DMA), and Fourier-transform infrared spectroscopy (FT-IR) were employed to characterize the effects of this exposure on these samples. This technical re… more

Date: January 7, 2003

Creator: Clark, E.A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

LDRD final report on nanocomposite materials based on hydrocarbon-bridged siloxanes

Silicones [polydimethylsiloxane (PDMS) polymers] are environmentally safe, nonflammable, weather resistant, thermally stable, low T{sub g} materials which are attractive for general elastomer applications because of their safety and their performance over a wide temperature range. However, PDMS is inherently weak due to its low glass transition temperature (T{sub g}) and lack of stress crystallization. The major goal of this project was to create a family of reinforced elastomers based on silse… more

Date: May 1, 1997

Creator: Ulibarri, T. A.; Bates, S. E.; Loy, D. A.; Jamison, G. M.; Emerson, J. A. & Curro, J. G.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Chemical and Physical Changes in a Hydrolyzed Poly(ester urethane)

Hydrolytic degradation has been shown to be a significant problem for poly(ester urethane) elastomers exposed to high humidity environments. The ester group in the soft segment is particularly susceptible to hydrolysis. One of the products of this reaction is a carboxylic acid group that catalyses further hydrolysis. The resulting reduction in molecular weight leads to deterioration of the elastomer's mechanical properties. In this paper we have measured the extent of the hydrolysis reaction by… more

Date: November 3, 1999

Creator: Assink, Roger A.; Celina, Mathias C. & Lang, David P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Novel CO{sub 2}-thickeners for improved mobility control

The objective of this study was to incorporate carbon dioxide-philic functionalities into the structure of a telechelic ionomers in an attempt to design a carbon dioxide-thickener. Alkyl analogs of these end-functionalized polymers have been successfully employed in dilute concentration to increase the viscosity of organic liquids or to induce gelation. The ionic end-groups associated in solution, establishing a viscosity enhancing macromolecular structure. More dramatic viscosity changes have … more

Date: February 2, 2000

Creator: Enick, Dr. Robert M.; Beckman, Dr. Eric J. & Hamilton, Dr. Andrew

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Increased Oil Recovery from Mature Oil Fields Using Gelled Polymer Treatments

Gelled polymer treatments were applied to oil reservoirs to increase oil production and to reduce water production by altering the fluid movement within the reservoir. This report is aimed at reducing barriers to the widespread use of these treatments by developing methods to predict gel behavior during placement in matrix rock and fractures, determining the persistence of permeability reduction after gel placement, and by developing methods to design production well treatments to control water… more

Date: March 28, 2001

Creator: Willhite, G.P.; Green, D.W. & McCool, S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Molecular size and structure in pyridine extracts of upper Freeport coal as separated by M41S sieving.

The determination of the structure of coal has long been of interest due to its crucial importance in research on reactivity and processing. However, the chemically and physically heterogeneous nature of coals makes determination of the chemical nature of even the building blocks complicated, since the molecular structure and molecular weight distribution are not dependent on a single molecule or repeat unit as in technical polymers or biopolymers, but on a complex mixture of molecules and pote… more

Date: July 2, 1999

Creator: Ahrens, M.; Hunt, J. E.; Winans, R. E. & Xu, L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Oxygen monitoring cells at Fermilab

Questions have been raised about the accuracy of oxygen monitoring for personnel safety around systems containing gases with a molecular weight less than nitrogen. A study has been performed to test the accuracy of the oxygen monitoring devices used at Fermilab. Portable and fixed oxygen monitoring equipment is used throughout Fermilab for personnel safety in defined oxygen deficiency hazard (ODH) areas. The results are presented as well as corrective measures taken to ensure accuracy and maint… more

Date: January 1, 2003

Creator: Theilacker, Jay C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Enhanced Trace-Fiber Color Discrimination by Electrospray Ionization Mass Spectrometry: A Quantitative and Qualitative Tool for the Analysis of Dyes Extracted from Sub-millimeter Nylon Fibers

The application of electrospray-ionization mass spectrometry (ESI-MS) to trace-fiber color analysis is explored using acidic dyes commonly employed to color nylon-based fibers, as well as extracts from dyed nylon fibers. Qualitative information about constituent dyes and quantitative information about the relative amounts of those dyes present on a single fiber become readily available using this technique. Sample requirements for establishing the color-identity of different samples (i.e., comp… more

Date: September 26, 2002

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Thermal degradation of poly({alpha}-methylstyrene) in solution. [Quarterly report, July--September 1995]

The thermal degradation of poly({alpha}-methylstyrene) in solution was investigated at various temperatures (150-225 C) and polymer concentrations (2.00-20.0 g/L) at 6.8 MPa (1000 psig). The molecular weight distributions (MWDs) of the reacted polymer at these conditions were examined at four different residence times. Experimental data indicated that the polymer degraded to its monomer, {alpha}-methylstyrene. No other degradation products were observed. Continuous-mixture kinetics was used to … more

Date: November 11, 1995

Creator: Madras, G.; Smith, J. M. & McCoy, B. J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Laser desorption mass spectrometry: Technical limitations, fundamentals, and application to coal

Objective of this study is to assess scope and limitations of laser desorption (LD) and matrix-assisted laser desorption (MALDI) as applied to coals. LD and MALDI mass spectrometry are increasingly used to detect intact molecular species, such as proteins with masses from 1000 to 100,000 amu and beyond. MALDI is also being used for high molecular weight polymers. A good example, related to coal-type systems, is the report on lignin mass spectrometry by MALDI. The mass spectrum shows a wide mole… more

Date: December 31, 1995

Creator: Hunt, J.E. & Winans, R.E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Vapor pressures and heats of vaporization of primary coal tars. Quarterly technical progress report, July 1 - September 31, 1996

The vapor pressure correlations that exist at present for coal tars are very crude and they are not considered reliable to even an order of magnitude. This project seeks to address this important gap in the near term by direct measurement of vapor pressures of coal tar fractions, by application of well-established techniques and modifications thereof. The principal objectives of the program are to: (1) obtain data on the vapor pressures and heats of vaporization of tars from a range of ranks of… more

Date: December 31, 1996

Creator: Suuberg, E.M.; Oja, V. & Lilly, W.D.

Item Type: Report

Partner: UNT Libraries Government Documents Department