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1999

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Articles 841 - 870 of 2555

Full-Text Articles in Physical Sciences and Mathematics

Reductive Dehydroxy Coupling Of 2-(Hydroxymethyl)Indenes To Prepare Ethano-Bridged Bis(2-Indenyl) Ansa-Titanocenes, Hasan Palandoken, Justin K. Wyatt, Shawn R. Hitchcock, Marilyn M. Olmstead, Michael H. Nantz May 1999

Reductive Dehydroxy Coupling Of 2-(Hydroxymethyl)Indenes To Prepare Ethano-Bridged Bis(2-Indenyl) Ansa-Titanocenes, Hasan Palandoken, Justin K. Wyatt, Shawn R. Hitchcock, Marilyn M. Olmstead, Michael H. Nantz

Chemistry and Biochemistry

New examples of ansa-titanocenes derived from 1,2-bis(2-indenyl)ethane have been prepared. The titanium-mediated reductive coupling of 2-(hydroxymethyl)indenes provided a convenient method for substrate dimerization. Alkyl substitution of the indene ring at C(3) improved the regioselectivity of the reductive coupling to provide the ethylene bis(2-indenyl)ansa-ligands in 29–62% yield.


Non-Rayleigh Signal Statistics In Clustered Statistically Homogeneous Rain, A. R. Jameson, Alexander Kostinski May 1999

Non-Rayleigh Signal Statistics In Clustered Statistically Homogeneous Rain, A. R. Jameson, Alexander Kostinski

Department of Physics Publications

As the sample volume of a remote sensing instrument moves through sufficiently variable conditions, recent work shows that the amplitudes and associated intensities can deviate significantly at times from expectations based on Rayleigh signal statistics because fluctuations in the number of scatterers leads to a doubly stochastic measurement process. While non-Rayleigh deviations yield average biases for both logarithmic and linear detectors, perhaps of greater importance is the enhancement of the variance of the bias distribution for square law detectors. In this work the authors explore the potential existence of non-Rayleigh effects even in the statistically homogeneous rain when fluctuations in …


Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 15, Number 5, May 1999, College Of Engineering And Computer Science, Wright State University May 1999

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 15, Number 5, May 1999, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

An eight page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.


The South Coast Estuarine Fishery. A Discussion Paper., Rod Pearn, Tony Cappelluti May 1999

The South Coast Estuarine Fishery. A Discussion Paper., Rod Pearn, Tony Cappelluti

Fisheries management papers

This discussion paper proposes a way for the South Coast Estuarine Fishery to address issues relating to the long-term sustainable management and sharing of the fish resource.


Proposals For Community Discussion. A Quality Future For Recreational Fishing In The Gascoyne. A Five-Year Management Strategy For Recreational Fishing., Gascoyne Recreational Fishing Working Group May 1999

Proposals For Community Discussion. A Quality Future For Recreational Fishing In The Gascoyne. A Five-Year Management Strategy For Recreational Fishing., Gascoyne Recreational Fishing Working Group

Fisheries management papers

Gascoyne has seen a series of rapid developments in recreational fisheries management, starting with the introduction of state-wide bag limits in 1991; followed by area specific controls at Ningaloo in 1992; landing limits in Exmouth Gulf in 1993; strict controls on the take of pink snapper in Shark Bay’s inner gulfs in 1997; new bag limits for Shark Bay in 1998; and the introduction of a management system for the charter and aquatic tour industry in 1999. The management proposals presented for community discussion in this paper are aimed at maintaining or improving the quality and diversity of the Gascoyne's …


The Exploration Of Artificial Intelligence Through The Analysis And Design Of Expert Systems, Avis R. Calvert May 1999

The Exploration Of Artificial Intelligence Through The Analysis And Design Of Expert Systems, Avis R. Calvert

Electronic Dissertations and Theses

Expert systems are a rapidly developing area of research. A sub-area of artificial intelligence, the success of expert systems depends heavily on an expert of a particular subject matter and that expert's ability to make analytical inferences based upon the human capacity to reason and deduce. Because the broad and ultimate goal of artificial intelligence is to develop computers capable of emulating human behavioral and psychoanalytical patterns, there is much to discover about the learning component of a computer. This thesis focuses on the development and the complexity of expert systems. Included, is a brief history of expert systems, a …


Selective Area Laser Induced Deposition Of Metal Borides, Veronica K. Holmes, Z. C. Zhong, P A. Dowben May 1999

Selective Area Laser Induced Deposition Of Metal Borides, Veronica K. Holmes, Z. C. Zhong, P A. Dowben

Electronic Dissertations and Theses

A novel technique, laser-induced solution deposition (LISD), has been developed for the selective area deposition of rare earth hexaborides. This technique was simple and efficient and combined advantages of chemical vapor deposition (CVD) and electrolytic deposition. The deposition of polycrystalline thin films of hexaborides and sub-borides, such as MB6, MB4, and MB2 (M = Gd, La), occurred by the light-initiated chemical reaction of nido-decaborane (B10H14) and rare earth chlorides in solution. These films grew with a strongly textured axis and had a morphology that was dependent on solvents and irradiation wavelength. Deposition of …


The Binding Of Selected Xenoestrogens To An Estrogen-Binding Fraction, Willie L. Washington May 1999

The Binding Of Selected Xenoestrogens To An Estrogen-Binding Fraction, Willie L. Washington

Electronic Dissertations and Theses

The purpose of this study was to test the hypothesis that effects of xenoestrogens may be mediated through a low-affinity estrogen-binding site. This low-affinity estrogen-binding site (EBS) is found in rat uterus. A second receptor, the Type I-(high-affinity-EBS). is also present in the uterus and other tissues. In order to obtain the estrogen-binding fraction-from the uterus, an ammonium sulfate (AS) fractionation was performed on rat-uterine cytosol. Two fractions were made, a 40% AS, which contained the Type I estrogen receptor (ER) and a 70¾ AS fraction that contained the low-affinity estrogen-binding site. These fractions were assayed for their ability to …


Identification And Characterization Of Biological And Volatile Organic Contaminants In Indoor Air In A Governmental State Office Building, Denesia A. Wallace May 1999

Identification And Characterization Of Biological And Volatile Organic Contaminants In Indoor Air In A Governmental State Office Building, Denesia A. Wallace

Electronic Dissertations and Theses

The purpose of this study was to identify and determine the concentrations of targeted inorganic gases and total volatile organic compounds known to exist in indoor air spaces. The Louisiana Department of Environmental Quality (LADEQ) Office Building was selected because of a survey of occupants' symptoms and perceptions of indoor air quality. Collected air samples were analyzed for selected compounds by way of United States Environmental Protection Agency (USEPA) sampling procedures and methods that utilized drager absorption tubes and a gas chromatograph/mass spectrometer. The targeted compounds were nitrogen dioxide, dinitrogen oxide, carbon monoxide, VOCs (volatile organic compounds), formaldehyde, and carbon …


Characterization Of Hypoxia: Topic 1 Report For The Integrated Assessment On Hypoxia In The Gulf Of Mexico, Nancy N. Rabalais, R. Eugene Turner, Dubravko Justic, Quay Dortch, William J. Wiseman May 1999

Characterization Of Hypoxia: Topic 1 Report For The Integrated Assessment On Hypoxia In The Gulf Of Mexico, Nancy N. Rabalais, R. Eugene Turner, Dubravko Justic, Quay Dortch, William J. Wiseman

Faculty Publications

No abstract provided.


The Allyl Leaving Group Approach To Tricoordinate Silyl, Germyl, And Stannyl Cations, Joseph B. Lambert, Yan Zhao, Hongwei Wu, Winston C. Tse, Barbara Kuhlmann May 1999

The Allyl Leaving Group Approach To Tricoordinate Silyl, Germyl, And Stannyl Cations, Joseph B. Lambert, Yan Zhao, Hongwei Wu, Winston C. Tse, Barbara Kuhlmann

Yan Zhao

A group 14 atom bonded to three mesityl groups (2,4,6-trimethylphenyl) and to one allyl group serves as a novel precursor to tricoordinate group 14 cations, the analogues of the carbocation. The double bond of the allyl group provides an accessible reaction site that is located beyond the ortho methyl groups. Reaction of various electrophiles with the double bond releases the allyl group and leads to formation of the group 14 cations. The mesityl groups then are of sufficient steric bulk to protect the tricoordinate metal center from attack by nucleophiles. This approach is used herein with silicon, germanium, and tin …


19. Makoto Okawara, Otto Vogl, Teiji Tsuruta, Seiichi Nakahama May 1999

19. Makoto Okawara, Otto Vogl, Teiji Tsuruta, Seiichi Nakahama

Otto Vogl

No abstract provided.


Σary, Moorhead State University, Mathematics Department May 1999

Σary, Moorhead State University, Mathematics Department

Math Department Newsletters

No abstract provided.


Santa Clara Magazine, Volume 41 Number 1, May 1999, Santa Clara University May 1999

Santa Clara Magazine, Volume 41 Number 1, May 1999, Santa Clara University

Santa Clara Magazine

8 - A BRIDGE BETWEEN WORLDS By President PaulL. Locatelli, S.J. 'Go. President Locatelli examines the value of service learning for students, the University, and America's social fabric.

12 - A GIANT ARTIST By Ann Granning Bennett. Auguste Rodin's sculptures are now on view at the de Saisset Museum. The question is: How do high-profile art shows like this one come about?

18 - ARIZONA'S DIPLOMATIC TOP COP By Tamara Straus. Janet Napolitano ' 79 , Arizona's newly elected attorney general , discusses the challenges of public office as well as politics, ethics, and fighting crime.


Thermoluminescence Evidence For The Deposition Of Coastal Sediments By Tsunami Wave Action, D. M. Price, Edward A. Bryant, R. W. Young May 1999

Thermoluminescence Evidence For The Deposition Of Coastal Sediments By Tsunami Wave Action, D. M. Price, Edward A. Bryant, R. W. Young

Faculty of Science - Papers (Archive)

Changes in our coastline take on various forms and are the product of differing wave and aeolian processes. Of all these processes tsunami action surely represents the most rapid and violent agent wreaking devastation not only along the immediate shoreline but also extending many kilometres inland. Until now the main line of evidence supporting the deposition of sediments by this means has lain in the careful examination of the sedimentological record. This process is painstaking, costly and time consuming and then not necessarily conclusive. Thermoluminescence may offer an alternative line of evidence which may be taken as either confirmatory or, …


An Agent-Based Design For Problem Solving Environments, Dan C. Marinescu May 1999

An Agent-Based Design For Problem Solving Environments, Dan C. Marinescu

Department of Computer Science Technical Reports

No abstract provided.


Biological Metaphors In He Design Of Complex Software Systems, Dan C. Marinescu, Ladislau Bölöni May 1999

Biological Metaphors In He Design Of Complex Software Systems, Dan C. Marinescu, Ladislau Bölöni

Department of Computer Science Technical Reports

No abstract provided.


Asymptotic Behavior Of The Height In A Digital Search Tree And The Longest Phrase Of The Lempel-Ziv Scheme, Charles Knessl, Wojciech Szpankowski May 1999

Asymptotic Behavior Of The Height In A Digital Search Tree And The Longest Phrase Of The Lempel-Ziv Scheme, Charles Knessl, Wojciech Szpankowski

Department of Computer Science Technical Reports

No abstract provided.


Neutron Resonance Spectroscopy Of 117sn From1 Ev To 1.5 Kev, D A. Smith, J D. Bowman, Bret E. Crawford, C A. Grossmann, T Haseyama, Mikkel B. Johnson, A Masaike, Y Matsuda, G E. Mitchell, V A. Nazarenko, S I. Penttila, N R. Roberson, S J. Seestrom, E I. Sharapov, L M. Smotritsky, Sharon L. Stephenson, V W. Yuan May 1999

Neutron Resonance Spectroscopy Of 117sn From1 Ev To 1.5 Kev, D A. Smith, J D. Bowman, Bret E. Crawford, C A. Grossmann, T Haseyama, Mikkel B. Johnson, A Masaike, Y Matsuda, G E. Mitchell, V A. Nazarenko, S I. Penttila, N R. Roberson, S J. Seestrom, E I. Sharapov, L M. Smotritsky, Sharon L. Stephenson, V W. Yuan

Physics and Astronomy Faculty Publications

Parity violation has been studied recently for neutron resonances in 117Sn. The neutron resonance spectroscopy is essential for the analysis of the parity violation data. We have measured neutron resonances in 117Sn for neutron energies from 1 to 1500 eV using the time-of-flight method and the (n,γ) reaction. The sample was enriched to 87.6% 117Sn. Neutron scattering and radiative widths were determined, and orbital angular momentum assignments were made with a Bayesian analysis. The s-wave and p-wave strength functions and average level spacings were determined.


The Decomposition Theorem For Two-Dimensional Shifts Of Finite Type, Aimee S. A. Johnson, K. M. Madden May 1999

The Decomposition Theorem For Two-Dimensional Shifts Of Finite Type, Aimee S. A. Johnson, K. M. Madden

Mathematics & Statistics Faculty Works

A one-dimensional shift of finite type can be described as the collection of bi-infinite "walks" along an edge graph. The Decomposition Theorem states that every conjugacy between two shifts of finite type can be broken down into a finite sequence of splittings and amalgamations of their edge graphs. When dealing with two-dimensional shifts of finite type, the appropriate edge graph description is not as clear; we turn to Nasu's notion of a "textile system" for such a description and show that all two-dimensional shifts of finite type can be so described. We then define textile splittings and amalgamations and prove …


Evaluating Snowmelt Runoff, Infiltration, And Erosion In A Sagebrush-Steppe Ecosystem, Eric K. Duffin May 1999

Evaluating Snowmelt Runoff, Infiltration, And Erosion In A Sagebrush-Steppe Ecosystem, Eric K. Duffin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Production of low-level radioactive waste (LLRW) has created a need for safe storage facilities. These facilities must be capable of isolating radioactive waste and preventing contamination from physical or biological intrusion until the waste material is isotopically stable. At the present time, managers of the Idaho National Engineering and Environmental Laboratory (INEEL) have a substantial database characterizing rainfall events and the subsequent impact on integrity of shallow land burial sites used for storage of LLRW. Little information has been gathered describing the processes of snow accumulation/ablation and the resulting impact on storage facilities. This study examines snowmelt runoff, infiltration, and …


Thermodynamic And Binding Studies Of Ligand-Carcinogen Dna Targets, Qianying Liang May 1999

Thermodynamic And Binding Studies Of Ligand-Carcinogen Dna Targets, Qianying Liang

Seton Hall University Dissertations and Theses (ETDs)

No abstract provided.


Insight Into The Selectivity Of Molecular Imprinted Polymers, Thomas Patrick O'Brien May 1999

Insight Into The Selectivity Of Molecular Imprinted Polymers, Thomas Patrick O'Brien

Seton Hall University Dissertations and Theses (ETDs)

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Parallel Algorithms For Large Sparse Generalized Elgin Problems (Ph.D. Thesis), Zhanye Tong May 1999

Parallel Algorithms For Large Sparse Generalized Elgin Problems (Ph.D. Thesis), Zhanye Tong

Department of Computer Science Technical Reports

No abstract provided.


Semiempirical R-Matrix Theory Of Low Energy Electron–Cf3Cl Inelastic Scattering, R. S. Wilde, Gordon A. Gallup, Ilya I. Fabrikant May 1999

Semiempirical R-Matrix Theory Of Low Energy Electron–Cf3Cl Inelastic Scattering, R. S. Wilde, Gordon A. Gallup, Ilya I. Fabrikant

Gordon Gallup Publications

We apply a semiempirical R-matrix theory to calculations of vibrational excitation and dissociative attachment in the CF3Cl molecule for electron energies below about 3 eV. We employ two sets of model parameters corresponding to two different forms of the CF3Cl potential curve. We find that our present, ab initio calculated anion curve gives vibrational excitation and dissociative attachment cross sections in good agreement with experimental measurements. We also compare the results of our theory with those of a recently published classical theory.


Defect-Induced Resonant Tunneling Of Electromagnetic Waves Through A Polariton Gap, Lev I. Deych, Alexey Yamilov, Alexander A. Lisyansky May 1999

Defect-Induced Resonant Tunneling Of Electromagnetic Waves Through A Polariton Gap, Lev I. Deych, Alexey Yamilov, Alexander A. Lisyansky

Physics Faculty Research & Creative Works

We consider tunneling of electromagnetic waves through a polariton band gap of a 1-D chain of atoms. We analytically demonstrate that a defect embedded in the structure gives rise to the resonance transmission at the frequency of a local polariton state associated with the defect.


Effects Of Resonant Tunneling In Electromagnetic Wave Propagation Through A Polariton Gap, Lev I. Deych, Alexey Yamilov, Alexander A. Lisyansky May 1999

Effects Of Resonant Tunneling In Electromagnetic Wave Propagation Through A Polariton Gap, Lev I. Deych, Alexey Yamilov, Alexander A. Lisyansky

Physics Faculty Research & Creative Works

We consider tunneling of electromagnetic waves through a polariton band gap of a one-dimensional chain of atoms. We analytically show that a defect embedded in the structure gives rise to the resonance transmission at the frequency of a local polariton state associated with the defect. Numerical Monte Carlo simulations are used to examine properties of the electromagnetic band arising inside the polariton gap due to finite concen-tration of defects.


Experimental Studies Of Magnetic Reconnection, Michael R. Brown May 1999

Experimental Studies Of Magnetic Reconnection, Michael R. Brown

Physics & Astronomy Faculty Works

Laboratory magnetic reconnection experiments have been performed for nearly 20 years. Elegant experiments by Stenzel and Gekelman [R. L. Stenzel and W. Gekelman, Phys. Rev. Lett. 42, 1055 (1979); W. Gekelman and R. L. Stenzel, Phys. Rev. Lett. 54, 2414 (1985)] focused on the measurement of field quantities with a single movable probe in a highly reproducible plasma. Observations included a very thin current sheet (on the order of c/ωpe), accelerated electrons, and whistler waves. The argon ions were unmagnetized in these experiments. Recent magnetohydrodynamic (MHD) experiments by Yamada and Ono have used merging plasmoids [M. Yamada, Y. Ono, A. …


Radiocarbon In Marine Bacteria: Evidence For The Ages Of Assimilated Carbon, J Cherrier, Je Bauer, Et Al May 1999

Radiocarbon In Marine Bacteria: Evidence For The Ages Of Assimilated Carbon, J Cherrier, Je Bauer, Et Al

VIMS Articles

It is generally accepted that marine bacteria utilize labile, recently produced components of bulk dissolved organic matter. This interpretation is based largely on indirect measurements using model compounds and plankton-derived organic matter. Here, we present an assessment of the relative proportions of modem and older dissolved organic carbon (DOC) utilized by marine bacteria. Bacterial nucleic acids were collected from both estuarine (Santa Rosa Sound, FL) and open-ocean (eastern North Pacific) sites, and the natural radiocarbon signatures of the nucleic acid carbon in both systems were determined. Bacterial nucleic acids from Santa Rosa Sound were significantly enriched in radiocarbon with respect …


Effect Of Dipolar Molecules On Carrier Mobilities In Photorefractive Polymers, Arosha Goonesekera, Stephen Ducharme May 1999

Effect Of Dipolar Molecules On Carrier Mobilities In Photorefractive Polymers, Arosha Goonesekera, Stephen Ducharme

Stephen Ducharme Publications

The grating formation speed in photorefractive polymers is greatly reduced by highly polar molecules incorporated by necessity in large concentrations to produce large diffraction efficiency and two-beam energy coupling gain. The random electric fields generated by these dipoles interfere with charge transport by increasing the width of the hopping site energy distribution and thus greatly reducing the carrier mobility and the photorefractive speed. We conducted transport studies of several model systems consisting of combinations of two polymer binders, six charge transport agents (four for holes and two for electrons), and varying concentrations of two highly polar electro-optic chromophores. The results …