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The Impact Of Latin American Debt Crisis On U.S., U.K., And Canadian Bank Stocks., Subbarao Venkata Jayanti Jan 1991

The Impact Of Latin American Debt Crisis On U.S., U.K., And Canadian Bank Stocks., Subbarao Venkata Jayanti

LSU Historical Dissertations and Theses

The 1980s have been a decade of crisis for banks engaged in international lending. This dissertation examines the impact of twelve events related to the Latin American debt crisis on the market value of the U.S., U.K., and Canadian bank stocks. The existing literature is extended in several directions. First, different types of events and several events of the same type are analyzed to enhance the generality of the conclusions. Second, a general theoretical framework involving two testable hypotheses is utilized to interpret the economic significance of the events. Third, the capital regulation hypothesis is tested extensively and it helped …

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Metabolism And Mutagenicity Of Dinitropyrenes: Effect Of Chronic Ethanol Ingestion And Aroclor 1254 Pretreatment., Antal Karl Hajos Jan 1991

Metabolism And Mutagenicity Of Dinitropyrenes: Effect Of Chronic Ethanol Ingestion And Aroclor 1254 Pretreatment., Antal Karl Hajos

LSU Historical Dissertations and Theses

The nitroreduction of three potently mutagenic dinitropyrene (DNP) isomers by liver cytosol from Aroclor-1254-pretreated rats was studied. NAD(P)H-quinone oxidoreductase (NQOR) is increased 12- to 24-fold by this treatment and resulted in up to 5-fold induction of cytosolic DNP-nitroreductase as compared to chow-fed controls. Upon purification, NQOR activity towards menadione coeluted with C-nitroso- and 1,6-DNP nitroreductase activity. Purified NQOR catalyzed NAD(P)H-dependent reduction of all DNP, displayed the same isomer specificity as did cytosol and increased the mutagenicity of all DNP in the Ames assay up to 3-fold. In TA98NR, a strain deficient in nitroreductase, only the mutagenicity of 1,3-DNP was markedly …

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An Analysis Of The Characterizations Of Aida And Amneris., Myrtle Yvette Mcdaniel Jan 1991

An Analysis Of The Characterizations Of Aida And Amneris., Myrtle Yvette Mcdaniel

LSU Historical Dissertations and Theses

Giuseppe Verdi's Aida has been well received by audiences since its inception. The plot of the opera centers around the relationships among Aida, her antagonist Amneris, and Radames. The two women display similar characteristics that provide not only the nucleus of their unique entities, but the themes around which the drama is constructed. The purpose of this analysis is to identify, contrast and compare points of characterization that define Aida and Amneris. These characteristics are traced from the original story by Auguste Mariette through three stages of development by Verdi: preversification, versification, and production. Chapter One begins with a brief …

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An Empirical Analysis Of Ricardian Equivalence And Macroeconomic Interdependence In Korea., Jang Cheon Jin Jan 1991

An Empirical Analysis Of Ricardian Equivalence And Macroeconomic Interdependence In Korea., Jang Cheon Jin

LSU Historical Dissertations and Theses

The dissertation research has two objectives. The first is to investigate the relevance of Ricardian equivalence to the Korean economy. The second objective is to investigate the empirical validity of the proposition of macroeconomic interdependence in Korea. The above two issues are examined by specifying and estimating a vector autoregressive (VAR) model as a compact approximation of macroeconomic reality in Korea. The nine variables selected for the VAR model are based upon theoretical and institutional considerations. Monthly Korean data for the period 1973:5-1989:11 are used in the analysis. First differencing for eight of the system variables is determined by unit …

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Pcr Amplification Of Chlamydial Momp Genes: Detection, Sequence Analysis And Evolution., Bernhard Kaltenboeck Jan 1991

Pcr Amplification Of Chlamydial Momp Genes: Detection, Sequence Analysis And Evolution., Bernhard Kaltenboeck

LSU Historical Dissertations and Theses

Sensitive detection and differentiation of the bacterial genus Chlamydia (C.) was accomplished using the polymerase chain reaction (PCR), and phylogenetic relationships among chlamydiae were inferred from DNA sequences of amplified major outer membrane protein (MOMP) genes. DNA of strains of C. psittaci was efficiently amplified using primers homologous to nontranslated regions of the MOMP genes (ompA). Portions of these reactions were reamplified using one different primer specific for an internal ompA sequence. Primary amplification products were differentiated by restriction analysis. Degenerate, inosine containing oligonucleotide primers homologous to terminal translated regions amplified DNA fragments of all chlamydial MOMP genes. Partial ompA …

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Thermohaline And Hydrocarbon Related Diagenesis Of Lower Miocene And Upper Oligocene Sediments, West Hackberry Field, Cameron Parish, Louisiana: Implications For Mass Transport And Fluid Flow., Kathleen Mary Mcmanus Jan 1991

Thermohaline And Hydrocarbon Related Diagenesis Of Lower Miocene And Upper Oligocene Sediments, West Hackberry Field, Cameron Parish, Louisiana: Implications For Mass Transport And Fluid Flow., Kathleen Mary Mcmanus

LSU Historical Dissertations and Theses

The diagenesis of Lower Miocene and Upper Oligocene sediments flanking the West Hackberry salt dome are documented in order to determine the effect the presence of salt domes may have in driving diagenetic reactions in detrital siliciclastic sediments. These sediments have undergone significant chemical diagenesis during progressive burial resulting in a reduction in porosity and permeability. Precipitation of analcime, siderite, and calcite plus the alteration of detrital volcanic lithic fragments and replacement of aluminosilicate framework grains by calcite are the dominant reactions which have altered the Upper Oligocene sands. Analcime and siderite are also present in the Oligocene mudstones. The …

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An Investigation Of The Contribution Of Auditory-Grouping To The Comodulation Masking Release Effect., Patrick Wynn Rappold Jan 1991

An Investigation Of The Contribution Of Auditory-Grouping To The Comodulation Masking Release Effect., Patrick Wynn Rappold

LSU Historical Dissertations and Theses

The comodulation masking release (CMR) effect involves improved detection of a pure-tone signal in an amplitude-modulated (AM) masker by an addition of AM noise spectrally distant from the signal (i.e, outside the critical-band of the signal). The underpinning of CMR has been elusive, and despite many previous investigations of this phenomenon it remains unexplained. A plausible explanation of CMR involves perceptual, auditory-grouping of acoustic signals. The purpose of this project was to investigate an hypothesis based on auditory-grouping to explain the CMR effect. A series of three experiments was completed towards this purpose. In the first, signal detection thresholds were …

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Conceptus-Derived Immunosuppressive Factors And Their Role In Fetal Allograft Protection., Terri Lynn Roth Jan 1991

Conceptus-Derived Immunosuppressive Factors And Their Role In Fetal Allograft Protection., Terri Lynn Roth

LSU Historical Dissertations and Theses

The role of conceptus-derived immunosuppressive factors in protecting the fetal allograft was investigated by first examining the immunosuppressive activity derived from ovine, caprine and hybrid conceptus trophoblast tissue. Medium conditioned by 20 day-old conceptus trophoblast tissue from each species suppressed sheep and goat lymphocyte proliferation (P $$.05) between the immunosuppressive effects of the three media on either sheep or goat lymphocytes. In subsequent studies, horse conceptus-conditioned medium (HCCM) derived from embryos at days 9, 15 and 26 of gestation, suppressed mitogen-stimulated horse lymphocytes (P $<$.001). HCCM maintained its suppressive activity following heating and repeated freeze-thawing. Using microconcentrator centrifugation, it was determined that the suppressor factor(s) was $>$100,000 MW. HCCM was tested in donkey and goat lymphocyte cultures and proved capable of …

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An Adaptive Differencing Scheme For Elliptic Flows., Therese Estelle Rhodes Jan 1991

An Adaptive Differencing Scheme For Elliptic Flows., Therese Estelle Rhodes

LSU Historical Dissertations and Theses

This thesis deals with the formulation of a computationally efficient multiple-grid adaptive differencing (MAD) scheme for two-dimensional elliptic flow and heat transfer problems. This algorithm equidistributes a measure of the error by using higher order differencing schemes locally in adaptively determined high error-estimate regions. The third-order accurate QUICK scheme is used in regions of high error estimate which are dynamically flagged on the basis of a preliminary first order upwind solution. Boundary conditions for the flagged regions are taken from the preliminary upwind solution. Multigrid type calculations are performed. Three multiple-grid schemes are developed. In the first scheme, MAD1-WFDS, the …

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Studies On Cigarette Smoke: I. Inactivation Of Alpha-1-Pi. Ii. Oxidation Of Methionine By Peroxonitrite. Iii. Release Of Iron From Ferritin By Smoke Solutions., Juan Jose Moreno R. Jan 1991

Studies On Cigarette Smoke: I. Inactivation Of Alpha-1-Pi. Ii. Oxidation Of Methionine By Peroxonitrite. Iii. Release Of Iron From Ferritin By Smoke Solutions., Juan Jose Moreno R.

LSU Historical Dissertations and Theses

We have studied the interaction of cigarette smoke with two proteins: alpha-1-proteinase inhibitor ($\alpha$1PI) and ferritin. The inactivation of $\alpha$1PI, the major plasma inhibitor of serine proteases, by cigarette smoke has been implicated in the eitology of pulmonary emphysema. Release of iron from ferritin, the principal source of physiological iron, by cigarette smoke could explain increased amounts of iron observed in the pulmonary alveolar macrophages of smokers. These studies show that cigarette smoke reacts with proteins to cause amino acid modifications by two mechanisms: oxidation of methionine and nonoxidative modification of the basic amino acids. Modifications of methionine and lysine …

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An Analysis Of Sequential Patterns Of Instruction In Piano Lessons., Donald Ray Speer Jan 1991

An Analysis Of Sequential Patterns Of Instruction In Piano Lessons., Donald Ray Speer

LSU Historical Dissertations and Theses

The purpose of this study was to investigate verbal behaviors of independent piano teachers in the setting of the private piano lesson. Twenty-five piano teachers from southeast Louisiana participated in the study. Teachers recorded the individual lessons of two students on audiotape. Verbatim transcripts were developed from a total of 47 recorded lessons. Transcripts were coded, identifying verbal behaviors with regard to components of sequential patterns established by Yarbrough and Price (1981, 1989). Verbal behaviors were analyzed for time spent in the categories of teacher presentation, student participation, and teacher reinforcement. Frequencies were obtained for the number of complete/correct, complete/incorrect, …

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Interfacial Adhesion In Rayon/Nylon Sheath/Core Composite Fibers., Weiying Tao Jan 1991

Interfacial Adhesion In Rayon/Nylon Sheath/Core Composite Fibers., Weiying Tao

LSU Historical Dissertations and Theses

Rayon/nylon sheath/core composite fibers with enhanced adhesion were produced using a wire coating type process. One objective of this research was to determine an effective coupling agent and the most appropriate application conditions for maximum interfacial adhesion in the rayon/nylon bicomponent fibers. The second objective was to characterize the interfacial adhesion between the core fiber and the rayon skin. It was found that fumaric acid (FA) was an effective adhesion promotor for rayon/nylon composite fibers since it has difunctionality and steric hinderance necessary to form covalent bonds to both layers. After removal of the spin finish by water washing the …

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Effects Of A Whole Language Approach Using Authentic French Texts On Student Comprehension And Attitude., Colette Hood Stelly Jan 1991

Effects Of A Whole Language Approach Using Authentic French Texts On Student Comprehension And Attitude., Colette Hood Stelly

LSU Historical Dissertations and Theses

The purpose of this study was to investigate the effects of a Whole Language Approach (WLA), using authentic French stories, on measures of listening and reading comprehension of fourth-year high school students of French, and on their attitudes to learning French, as opposed to students using customary textbook materials in a conventional teacher-centered classroom setting. This investigation comprised two components: (a) a quantitative component which statistically determined results on measures of listening, reading and attitude, and, (b) a qualitative component which reviewed classroom procedures through observation and interview. Analysis of variance on four separate posttests showed statistically significant differences in …

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An Examination Of Auditor Changes Following Events Adversely Affecting External Auditor Credibility., Thomas E. Wilson Jr Jan 1991

An Examination Of Auditor Changes Following Events Adversely Affecting External Auditor Credibility., Thomas E. Wilson Jr

LSU Historical Dissertations and Theses

This study examines auditor changes following events adversely affecting auditor credibility. Disciplinary actions against auditors by the Securities and Exchange Commission (SEC) are posited to be events damaging to auditor credibility. Agency theory and prior research are used to generate hypotheses about differences between client firms that switch auditors and client firms that do not switch auditors after an SEC action under Rule 2(e) against their auditor. A series of univariate and multivariate statistical tests are conducted on the sample firms. The sample is divided into a Switch group and a Non-Switch group. The sample as a whole is examined, …

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Methyl Oleate Ozonides In Aqueous Micelles: Formation, Stability, And Initiation Of Lipid Peroxidation, And, Relative Antioxidant Efficiencies In Aqueous Micelles Of Anionic And Cationic Surfactants., Mingdan Wu Jan 1991

Methyl Oleate Ozonides In Aqueous Micelles: Formation, Stability, And Initiation Of Lipid Peroxidation, And, Relative Antioxidant Efficiencies In Aqueous Micelles Of Anionic And Cationic Surfactants., Mingdan Wu

LSU Historical Dissertations and Theses

Ozonation of methyl oleate has been shown for the first time to form ozonides in aqueous micelles of sodium dodecyl sulfate (SDS) and in L-$\alpha$-distearoyl-phosphatidylcholine (DSPC) liposomes. The total yield of ozonides in 0.02 M SDS micelles exposed to 26 ppm ozone at pH 7.4 and 22$\sp\circ$C is 11.1%. This 11.1% consists of 7.5% of the normal ozonide (MOO2), ca. 4.2% of trans-isomer and ca. 3.3% of cis-isomer, and the rest 3.6% is accounted for by the cross ozonides (MOO1 and MOO3). Regarding the hydrolytic stability of the ozonides under physiologically relevant conditions (e.g., pH 7.4 and 37$\sp\circ$C), the half-lives …

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An Investigation Of The Laryngeal System As The Resonance Source Of The Singer's Formant., Rebecca Finley Detweiler Jan 1991

An Investigation Of The Laryngeal System As The Resonance Source Of The Singer's Formant., Rebecca Finley Detweiler

LSU Historical Dissertations and Theses

Since its introduction in 1974, Johan Sundberg's model of the laryngeal system as the resonance source of the singer's formant (Fs) has gained wide acceptance. There have heretofore been no studies directly testing its validity in vivo. The purpose of this study was to undertake a direct test of that hypothesis, utilizing as subjects professional male singers trained in the western Classical tradition. The vocal behaviors of three trained singer-subjects were evaluated during modal and pulse register phonation via magnetic resonance imaging (M.R.I.), strobolaryngoscopy, and acoustical analysis. Dr. Sundberg's hypothesis rests upon two premises: (1) that the laryngeal system is …

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Statistical Sophistication Of Research In Vocational Education., Chi Zhang Jan 1991

Statistical Sophistication Of Research In Vocational Education., Chi Zhang

LSU Historical Dissertations and Theses

The purpose of this study was to determine the status of, and changes in, the statistical sophistication of research in vocational education in the 1980s. The study also explored relationships among statistical sophistication, problem area studied, and methodological strategy used in vocational education research. Data collected were obtained from 118 quantitative research reports randomly selected from the Journal of Vocational Education Research, the Journal of Agricultural Education, the Journal of Industrial Teacher Education, and the Journal of Vocational Home Economics Education published in the early (1980-1983) and the late 1980s (1986-89). The researcher developed instrument used in this study consisted …

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Novel Alumina-Based Stationary Phases For Liquid Chromatography., Rene V. Arenas Jan 1991

Novel Alumina-Based Stationary Phases For Liquid Chromatography., Rene V. Arenas

LSU Historical Dissertations and Theses

The chromatographic properties of polymer-coated Unisphere aluminas for reversed-phase liquid chromatography were evaluated and compared to those of Si-C$\sb{18}$ phases. A greater difference in solvent strength between acetonitrile and methanol was observed for the Unisphere columns. Approximately equal methylene selectivity was also obtained for both stationary phase types. Evaluation of polar group selectivity showed the absence of hydroxyl group participation in solute retention for the aluminas. In terms of kinetic properties, acceptable reduced plate heights were obtained for the Unisphere columns at optimum velocities. However, the van Deemter curves for the aluminas showed a more rapid loss in efficiency with …

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In Vitro Studies On Cigarette Smoke-Mediated Damage To Human Alpha-1-Proteinase Inhibitor., Mark Dennis Evans Jan 1991

In Vitro Studies On Cigarette Smoke-Mediated Damage To Human Alpha-1-Proteinase Inhibitor., Mark Dennis Evans

LSU Historical Dissertations and Theses

The effect, in vitro, of water soluble components of the particulate phase of cigarette smoke on the elastase inhibitory capacity (EIC) of human alpha-1-proteinase inhibitor ($\alpha\sb1$PI) is studied. Basic features of aqueous cigarette tar extract-mediated damage to $\alpha\sb1$PI are presented, as are mechanistic studies addressing the identities of damaging species and the nature of damage to $\alpha\sb1$PI. Aqueous cigarette tar extract (ACT) causes a slow loss of EIC, and retains this $\alpha\sb1$ PI damaging ability for hours. The damage to $\alpha\sb1$PI by ACT is dependent on its hydrogen peroxide content. Hydroxyl radicals or hypervalent metal species in the homogeneous phase …

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A Multidimensional Career Commitment Measure (Mccm) Gauging Motivation To Work In One's Career Field., Kerry D. Carson Jan 1991

A Multidimensional Career Commitment Measure (Mccm) Gauging Motivation To Work In One's Career Field., Kerry D. Carson

LSU Historical Dissertations and Theses

Past career commitment measures have been redundant with other work commitment measures or have been narrowly defined as professionalism. Blau's (1985) definition of career commitment as one's attitude towards one's vocation seems to most closely represent this construct. However, his measure has several problems including construct overlap with career withdrawal intentions. Because of a developmental lag in the career focus domain due to lack of established measures, the reported research constructed and tested a theoretically based measure of career commitment. Development of a new career commitment measure was based on London's (1983) theory of career motivation consisting of three theoretical …

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An Examination Of Semiotic Theories Of Accounting Accruals., Harlan Lynn Etheridge Jan 1991

An Examination Of Semiotic Theories Of Accounting Accruals., Harlan Lynn Etheridge

LSU Historical Dissertations and Theses

Two theories of accounting accruals form the core of this study. The theory of the functions of accounting accruals is induced from observation of accounting accruals. One type of accounting accrual reflects incomplete transactions under a system of cash receipts and cash disbursements. The function of these accruals is to convey data about economic events associated with incomplete cash transactions. These accruals are referred to as syntactically redundant accruals. The second type of accounting accrual presents messages in a different format than their counterparts in a system of cash receipts and cash disbursements. The function of these accruals is to …

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The Rhodobacter Capsulatushema Region: Nucleotide Sequence And Functional Analysis., John Joseph Eckert Jan 1991

The Rhodobacter Capsulatushema Region: Nucleotide Sequence And Functional Analysis., John Joseph Eckert

LSU Historical Dissertations and Theses

Most of the effort to elucidate the mechanism of oxygen-mediated regulation of tetrapyrrole biosynthesis in Rhodobacter capsulatus has focused on the first step in the biosynthetic pathway, the condensation of glycine with succinyl-CoA to form $\delta$-aminolevulinic acid. This reaction, in R. capsulatus, is catalyzed by $\delta$-aminolevulinate synthase, the product of the hemA gene. In order to facilitate further study of the hemA gene and its product, its nucleotide sequence was determined. The open reading frame encoding $\delta$-aminolevulinate synthase was determined to be 1,206 base pairs, encoding a 50,491 Da polypeptide of 401 amino acids. The DNA sequence was compared with …

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The Pirates' Wake: A Geography Of Piracy And Pirates As Geographers In Colonial Spanish America, 1536-1718. (Volumes I And Ii)., Peter Reppert Galvin Jan 1991

The Pirates' Wake: A Geography Of Piracy And Pirates As Geographers In Colonial Spanish America, 1536-1718. (Volumes I And Ii)., Peter Reppert Galvin

LSU Historical Dissertations and Theses

This geographical study of piracy in Spanish America spans from 1536, the beginning date of sustained piratical activity there, to the near dispersion of pirate forces by 1718. It identifies and relates the operations of sixteenth-century corsairs such as Francis Drake, seventeenth-century buccaneers such as Henry Morgan, and eighteenth-century freebooters such as 'Blackbeard'. Regional coverage focuses on Middle America with an occasional foray into the South Sea. The principal national agents considered are English, French, Dutch, and Spanish. The study begins by deriving a working definition of pirates and examining precedent spatial approaches by Henry Mainwaring, Ellen Semple, and Derwent …

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Biosynthetic Studies Of Hairy Root Constituents Of The Heliantheae (Asteraceae) And Phytochemical Screening Of Members Of The Magnoliaceae., Marco Luis Gomez-Barrios Jan 1991

Biosynthetic Studies Of Hairy Root Constituents Of The Heliantheae (Asteraceae) And Phytochemical Screening Of Members Of The Magnoliaceae., Marco Luis Gomez-Barrios

LSU Historical Dissertations and Theses

The major chemical constituents of Magnolia acuminata, M. ashei, M. cordata, M. dealbata, M. fraseri, M. freemani, M. little gem, M. macrophylla, M. tripetala and M. virginiana were studied as part of a continuing search for biologically active secondary metabolites from regional plant sources and the investigation of their biosynthesis and large scale production. All these Magnolia species are rich in fatty acids and several also contain monoterpenes, sesquiterpenes, sesquiterpene lactones and lignans. The organic extract of the leaves of Magnolia virginiana provided a new sesquiterpene lactone, 4,14-dehydromagnograndiolide, and the new sesquiterpene lactol costunolactol. The known sesquiterpene lactones parthenolide and …

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Formation Of Methylmercaptan And Dimethylsulfide From Methoxylated Aromatic Compounds In Anoxic Marine And Fresh Water Sediments, Kai Finster, Gary M. King, Friedhelm Bak Dec 1990

Formation Of Methylmercaptan And Dimethylsulfide From Methoxylated Aromatic Compounds In Anoxic Marine And Fresh Water Sediments, Kai Finster, Gary M. King, Friedhelm Bak

Faculty Publications

Anaerobic formation of dimethylsulfide (DMS) and methylmercaptan (MSH) in anoxic sulfide-containing slurries from marine and fresh water sediments was stimulated by addition of syringate (4-hydroxy,3,5,-dimethoxybenzoate) and 3,4,5,-trimethoxybenzoate. The release of DMS and MSH occurred during the consumption of the aromatic monomers and ceased after their depletion. DMS was the dominant methylated sulfur compound in fresh water sediments, in contrast to marine sediments where MSH was predominant. No production of volatile organic sulfur compounds was observed in slurries containing gallate (3,4,5,-trihydroxybenzoate) or in autoclaved controled. About 50-65% of the methoxy carbon could be accounted for by peak accumulation of DMS and …

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Faculty Senate Resolution 90-03, Louisiana State University And Agricultural & Mechanical College Dec 1990

Faculty Senate Resolution 90-03, Louisiana State University And Agricultural & Mechanical College

LSU Faculty Senate Publications

Faculty Senate Resolution on an ad hoc committee on instructor positions, adopted on December 6, 1990.

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Faculty Senate Resolution 90-04, Louisiana State University And Agricultural & Mechanical College Dec 1990

Faculty Senate Resolution 90-04, Louisiana State University And Agricultural & Mechanical College

LSU Faculty Senate Publications

Faculty Senate Resolution on an ad hoc committee on research ladder positions, adopted December 6, 1990.

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Structure And Variability Of Recently Inserted Alu Family Members, Mark A. Batzer, Gail E. Kilroy, Pamela E. Richard, Tamim H. Shaikh, Trent D. Desselle, Carol L. Hoppens, Prescott L. Deininger Dec 1990

Structure And Variability Of Recently Inserted Alu Family Members, Mark A. Batzer, Gail E. Kilroy, Pamela E. Richard, Tamim H. Shaikh, Trent D. Desselle, Carol L. Hoppens, Prescott L. Deininger

Faculty Publications

The HS subfamily of Alu sequences is comprised of a group of nearly identical members. Individual subfamily members share 97.7% nucleotide identity with each other and 98.9% nucleotide identity with the HS consensus sequence. Individual subfamily members are on the average 2.8 million years old, and were probably derived from a single source 'master' gene sometime after the human/great ape divergence. The recent Alu family member insertions provide a better image of the structure of Alu retroposons before they have had the opportunity to change significantly. All of the HS subfamily members are flanked by perfect direct repeats as a …

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Weak Localisation Theory For Lightly Doped Semiconductor Quantum Wires, G. Y. Hu, R. F. O'Connell Dec 1990

Weak Localisation Theory For Lightly Doped Semiconductor Quantum Wires, G. Y. Hu, R. F. O'Connell

Faculty Publications

A weak localisation theory for a semiconductor quantum wire, which has a width of the order of the Fermi wavelength is presented. In the model the electronic motion is essentially one-dimensional and the localisation length L1 is much larger than the mean free path l, so that, in contrast to conventional theories a non-localised quantum wire with a total length Lproperties, the authors study the temperature dependence and the subbands effect of the weak localisation. They find that when (the phase coherent length) Lphi>L, the conductance of the quantum wire depends on L instead of Lphi, implying a temperature …

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Dielectric Response Of A Quasi-One-Dimensional Electron System, G. Y. Hu, R. F. O'Connell Dec 1990

Dielectric Response Of A Quasi-One-Dimensional Electron System, G. Y. Hu, R. F. O'Connell

Faculty Publications

The dielectric response of a quasi-one-dimensional electron system is studied by including fluctuation effects (in the polarizability) and by using a recently derived analytic form for the electron-electron interactions. General forms for the polarizability matrices both for the intra- and inter-subband cases are presented. The generalized polarizability is analytic over the whole region of the wavevectors and rigorously retains the number neutrality. Various differences between the intra- and inter-subband cases for the polarizability and the dielectric matrix function are studied. The theory is used to study impurity screening and plasmon excitations in the presence of multi-subbands. The authors show that …

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