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1998

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Articles 2101 - 2130 of 2339

Full-Text Articles in Physical Sciences and Mathematics

Continuous Lake-Sediment Records Of Glaciation In The Sierra Nevada Between 52,600 And 12,500 14c Yr B.P., Larry Benson, Howard M. May, Ronald C. Antweiler, Terry I. Brinton, Michaele Kashgarian, Joseph P. Smoot, Steve P. Lund Jan 1998

Continuous Lake-Sediment Records Of Glaciation In The Sierra Nevada Between 52,600 And 12,500 14c Yr B.P., Larry Benson, Howard M. May, Ronald C. Antweiler, Terry I. Brinton, Michaele Kashgarian, Joseph P. Smoot, Steve P. Lund

United States Geological Survey: Staff Publications

The chemistry of the carbonate-free clay-size fraction of Owens Lake sediments supports the use of total organic carbon and magnetic susceptibility as indicators of stadial-interstadial oscillations, Owens Lake records of total organic carbon, magnetic susceptibility, and chemical composition of the carbonate-free, clay-size fraction indicate that Tioga glaciation began ~24,500 and ended by ~13,600 14C yr B.P. Many of the components of glacial rock flour (e.g., TiO2 , MnO, BaO) found in Owens Lake sediments achieved maximum values during the Tioga glaciation when valley glaciers reached their greatest extent. Total organic carbon and Si02 (amorphous) concentrations reached minimum values …


Early Life History Stages Of Gulf Sturgeon In The Suwannee River, Florida, Kenneth J. Sulak, James P. Clugston Jan 1998

Early Life History Stages Of Gulf Sturgeon In The Suwannee River, Florida, Kenneth J. Sulak, James P. Clugston

United States Geological Survey: Staff Publications

Egg sampling confirmed that Suwannee River Gulf sturgeon Acipenser ozyrinchus desotoi, a subspecies of Atlantic sturgeon A. o. oxyrinchus use the same spawning site at river kilometer (rkm) 215 from the mouth of the river each year. Forty-nine eggs were recorded in 1995, and 368 were recorded in 1996. Spawning began 4-7 d after the March new moon in both years and lasted 10-11 d; in 1996, a second 10-d spawning round began on the April new moon. Developmental synchrony among eggs recovered suggested serval discrete spawning events in both years. Total eggs deposited for three 1996 sampling days …


Π-Systems As Lithium/Hydrogen Bond Acceptors: Some Theoretical Observations, Salai Cheettu Ammal, P. Venuvanalingam Jan 1998

Π-Systems As Lithium/Hydrogen Bond Acceptors: Some Theoretical Observations, Salai Cheettu Ammal, P. Venuvanalingam

Faculty Publications

Ab initio calculations at the Hartree–Fock and correlated levels and density functional theory calculations have been performed with 6-31++G(d,p) and 6-311++G(d,p)basis sets on LiF and HF complexes of benzene, ethylene, and acetylene. Complex binding energies have been corrected for basis set superposition error, and zero point energy corrections have been done on Hartree–Fock binding energies. Computed results indicate that the complexes exist in different conformations and among them those with π-lithium and π-hydrogen bonds are the most stable. π-lithium bonds are stronger than π-hydrogen bonds. The computed binding energies and geometry of HF complexes correlate well with the available experimental …


Ab Initio And Dft Investigations Of Lithium/Hydrogen Bonded Complexes Of Trimethylamine, Dimethyl Ether And Dimethyl Sulfide, Salai Cheettu Ammal, P. Venuvanalingam Jan 1998

Ab Initio And Dft Investigations Of Lithium/Hydrogen Bonded Complexes Of Trimethylamine, Dimethyl Ether And Dimethyl Sulfide, Salai Cheettu Ammal, P. Venuvanalingam

Faculty Publications

Ab initio and DFT computations have been carried out on LiF and HF complexes of a set of n-donors viz. trimethylamine, dimethyl ether and dimethyl sulfide with a 6-31++G(d,p) basis set. The effect of correlation has been included with MP2, MP4 and DFT calculations. NBO analyses of the wavefunctions have been performed to examine the intermolecular interaction at the orbital level. Calculations reveal that these donors form strong n→σ* complexes and computed binding energies of the (CH3)2O···HF complex agree very well with the experimental binding energies from IR spectroscopy. LiF forms stronger complexes than HF, …


สัมภาษณ์ : เอล นิโน ในทัศนะของนักอุตุนิยมวิทยา ดร. ปฎิพัทธ์ พัทธ์วิวัฒน์ศิริ, กองบรรณาธิการ Jan 1998

สัมภาษณ์ : เอล นิโน ในทัศนะของนักอุตุนิยมวิทยา ดร. ปฎิพัทธ์ พัทธ์วิวัฒน์ศิริ, กองบรรณาธิการ

Thai Environment

No abstract provided.


การใช้งานระบบสารสนเทศทางภูมิศาสตร์ ที่เกี่ยวกับสิ่งแวดล้อม, ลักษมี Jan 1998

การใช้งานระบบสารสนเทศทางภูมิศาสตร์ ที่เกี่ยวกับสิ่งแวดล้อม, ลักษมี

Thai Environment

No abstract provided.


แนะนำกิจกรรมของสถาบันวิจัยสภาวะแวดล้อม : เว็บไซต์ฐานข้อมูลการเปลี่ยนแปลงของโลกในประเทศไทย, อุษณีย์ Jan 1998

แนะนำกิจกรรมของสถาบันวิจัยสภาวะแวดล้อม : เว็บไซต์ฐานข้อมูลการเปลี่ยนแปลงของโลกในประเทศไทย, อุษณีย์

Thai Environment

No abstract provided.


Optical Digital Fragmentation Measuring Systems -- Inherent Sources Of Error, Norbert H. Maerz, Wei Zhou Jan 1998

Optical Digital Fragmentation Measuring Systems -- Inherent Sources Of Error, Norbert H. Maerz, Wei Zhou

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Automated optical imaging systems of measuring fragmentation are increasingly being used in the mining, comminution, and materials handling industries. These methods have been well received in many of the industries involved. Considering that in many of these applications there are no alternative ways of sizing material, having even a rudimentary measurement of size distributions allows evaluations of explosive, blast design, detonator performance, crusher and milling performance, and material degradation due to transport.

Optical methods have inherent limitations, which reflect on accuracy, precision, and reproducibility of measurement results. This stems from the fact that there are myriads of variables, which affect …


Aegis Data Analysis And Reduction (Adar) In Support Of The Aegis Weapon System (Aws), June Bullard Gaines Jan 1998

Aegis Data Analysis And Reduction (Adar) In Support Of The Aegis Weapon System (Aws), June Bullard Gaines

Theses and Dissertations

The AEGIS Weapons System (AWS), part of the AEGIS Combat System (ACS), is an integral part of the defense system on U.S. Navy AEGIS-class ships. AEGIS Data Analysis and Reduction (ADAR) has been developed to assist in the evaluation of the AWS data. ADAR, along with the AWS and ACS, has evolved through the years to accommodate advances in technology and computer programming languages. Additionally, ADAR has evolved so that users located at sites other than the Naval Surface Warfare System Dahlgren Division (NSWCDD), Dahlgren, Virginia, can reduce tactical system data and perform data analysis using the reduced data.

This …


A Tour Of Mistakes, Paul H. Edelman Jan 1998

A Tour Of Mistakes, Paul H. Edelman

Vanderbilt Law School Faculty Publications

In these pages, Steven Lubet recently reviewed A Tour of the Calculus, by David Berlinski. Inspired by both the beauty of calculus and Berlinski's description of it, Lubet waxes poetic on the many parallels between the law and calculus. It is completely understandable--even admirable that one might be led to ruminations on the relationship between calculus and one's own discipline. There is little doubt that the subject of calculus stands as one of the great intellectual feats of Western thought. It has had profound implications for physics, engineering, economics and many other disciplines-so why not law? Alas, these philosophical musings …


Diode Lasers And Their Application For Raman Spectroscopy, Richard Bandell Homard Jan 1998

Diode Lasers And Their Application For Raman Spectroscopy, Richard Bandell Homard

Theses and Dissertations

Diode lasers are semiconductor devices and as such are small, relatively inexpensive, and modest in power requirements. They are being used more and more in a variety of spectroscopic measurement systems. Diodes can be configured to provide a single wavelength for Raman measurement or be tuned over a 10-20 nm range for absorption studies. Most commercial diode-based Raman systems currently employ lasers with output powers in the 100-1000 mW range. There are obvious strategic and economic advantages associated with low power diode chemical analyzers, especially those being developed for on-line industrial and environmental monitoring. A diode-based Raman measurement system which …


Adaptive Shape From Shading, Ati̇lla Gülteki̇n, Muhi̇tti̇n Gökmen Jan 1998

Adaptive Shape From Shading, Ati̇lla Gülteki̇n, Muhi̇tti̇n Gökmen

Turkish Journal of Electrical Engineering and Computer Sciences

Extracting surface orientation and surface depth from one or more images is one of the classic problems in computer vision. Shape-from-shading (SFS) deals with the recovery of 3-D shape from a single shaded image. The shape is recovered by minimizing an energy functional involving constraints such as smoothness. In this constrained problem, although the smoothness constraint helps to stabilize the minimization process, it pushes the reconstruction toward a smooth surface. In this paper, we present a new adaptive shape-from-shading method which reduces this oversmoothing by controlling the smoothness spatially over the image space. In order to improve the quality of …


A Parallel Pipelined Computer Architecture For Digital Signal Processing, Haluk Gümüşkaya, Bülent Örenci̇k Jan 1998

A Parallel Pipelined Computer Architecture For Digital Signal Processing, Haluk Gümüşkaya, Bülent Örenci̇k

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a parallel pipelined computer architecture and its six network configurations targeted for the implementation of a wide range of digital signal processing (DSP) algorithms described by both atomic and large grain data flow graphs. The proposed architecture is considered together with programmability, yielding a system solution that combines extensive concurrency with simple programming. It is an SSIMD (Skewed Single Instruction Multiple Data) or MIMD (Multiple Instruction Multiple Data) machine depending on the algorithms implemented and the programming methodologies. The concurrency that can be exploited by the algorithms using this Parallel pipelined architecture is both temporal and spatial …


Hierarchical Interconnection Network Architecture For Real-Time Systems, Bülent Örenci̇k Jan 1998

Hierarchical Interconnection Network Architecture For Real-Time Systems, Bülent Örenci̇k

Turkish Journal of Electrical Engineering and Computer Sciences

A hierarchical network suitable for interconnection of real-time client processes in a distributed multiprocessor environment is presented in this paper. A multi-layer {\it Communication Unit} (CU) prototype is developed for this purpose. This unit offers the client processes communication services for real-time operation. These services are structured in such a way that they do not depend on the characteristics of the communication medium. The basic hardware of the CU consists of a PC compatible card connected to the VME Bus. Client processes run on target cards (Motorola MVME-162) which are attached to the same bus. Target cards together with a …


Imaging Tissue Conductivity Via Contactless Measurements: A Feasibility Study, Nevzat G. Gençer, M. Nejat Tek Jan 1998

Imaging Tissue Conductivity Via Contactless Measurements: A Feasibility Study, Nevzat G. Gençer, M. Nejat Tek

Turkish Journal of Electrical Engineering and Computer Sciences

The feasibility of a new imaging system is investigated. This system will be used to image electrical conductivity distribution of biological tissues via contactless measurements. This will be achieved by introducing currents in the conductive medium using time-varying magnetic fields and measuring the magnetic fields of the induced currents. Consequently, the imaging system consists of transmitter and receiver coils placed nearby the conductive body. In this study, the basic features of the coplanar and coaxial coils are studied. The validity of the simplifying assumptions for the governing field equations is investigated. It is found that, for operating frequency of 100 …


Agricultural Water Quality Index Field Handout, Jeffrey Cooper, Richard Rediske, Melvin Northup, Mark Thogerson, Jonathan Van Denend Jan 1998

Agricultural Water Quality Index Field Handout, Jeffrey Cooper, Richard Rediske, Melvin Northup, Mark Thogerson, Jonathan Van Denend

Scientific Technical Reports

The Agricultural Water Quality Index (AWQI) is an assessment tool designed for use in agroecosystems. Most existing environmental indices and assessment tools focus on the stream channel and/or riparian zone (the area between the channel and active land use). In contrast, the AWQI places an emphasis on land use and soil types that play a significant role in hydrologic cycles and water quality characteristics within the watershed.

The AWQI is designed to be used by agricultural technicians with limited experience in aquatic ecology; however, it does assume a reasonable background in soil characteristics. This index is intended for use during …


Factorization For High-Energy Scattering, Ian Balitsky Jan 1998

Factorization For High-Energy Scattering, Ian Balitsky

Physics Faculty Publications

I demonstrate that the amplitude for the high-energy scattering can be factorized into a product of two independent functional integrals over “fast” and “slow” fields which interact by means of Wilson-line operators—gauge factors ordered along the straight lines.


Disproportionation And Structural Changes Of Tetraarylethylene Donors Upon Successive Oxidation To Cation Radicals And To Dications, Rajendra Rathore, Sergey V. Lindeman, A. S. Kumar, Jay K. Kochi Jan 1998

Disproportionation And Structural Changes Of Tetraarylethylene Donors Upon Successive Oxidation To Cation Radicals And To Dications, Rajendra Rathore, Sergey V. Lindeman, A. S. Kumar, Jay K. Kochi

Chemistry Faculty Research and Publications

The stepwise (one-electron) chemical oxidation of the tetraphenylethylene donor and its substituted analogues (D) can be carried out by electron exchange with aromatic cations or antimony(V) oxidants to selectively afford the cation radical (D+•) initially and then the dication (D2+). The ready interchange of the latter establishes the facile disproportionation (i.e., 2D+• ⇌ D2+ + D) that was originally examined by only transient electrochemical techniques. The successful isolations of the crystalline salts of the tetraanisylethylene cation radical (1+•) as well as the …


On The Differential Prime Radical Of A Differential Ring, Djavvat Khadjiev, Fethi̇ Çallialp Jan 1998

On The Differential Prime Radical Of A Differential Ring, Djavvat Khadjiev, Fethi̇ Çallialp

Turkish Journal of Mathematics

In this paper we have obtained the following results for a differential ring (associative or nonassociative): (1) For a differential ring ({\cal D}-ring) we introduce definitions of a {\cal D}-prime {\cal D}-ideal, {\cal D}-semiprime {\cal D}-ideal and a strongly {\cal D}-nilpotent element. We define the {\cal D}-prime radical as the intersection of all {\cal D}-prime {\cal D}-ideals. For any {\cal D}-ring the {\cal D}-prime radical, the intersection of all {\cal D}-semiprime {\cal D}-semiprime {\cal D}-ideals and the set of all strongly {\cal D}-nilpotent elements are equal. (2) For a {\cal D}-ring we introduce a definition of an s-nilpotent {\cal D}-ideal. …


Normal Subgroups Of Hecke Groups On Sphere And, İsmai̇l Naci̇ Cangül, Osman Bi̇zi̇m Jan 1998

Normal Subgroups Of Hecke Groups On Sphere And, İsmai̇l Naci̇ Cangül, Osman Bi̇zi̇m

Turkish Journal of Mathematics

We use regular map theory to obtain all normal subgroups of Hecke groups of genus 0 and 1. The existence of a regular map corresponding uniquely to every normal subgroup of Hecke groups H(\lambda_q) is a result of Jones and Singerman, and it is frequently used here to obtain normal subgroups. It is found that when q is even, H(\lambda_q) has infinitely many normal subgroups on the sphere, while for odd q, this number is finite. The total number of normal subgroups of H(\lambda_q) on a torus is found to be either 0 or infinite. The latter case appears iff …


Fuzzy Ideals In Gamma Near-Rings, Young Bae Jun, Mehmet Sapanci, Mehmet Ali̇ Öztürk Jan 1998

Fuzzy Ideals In Gamma Near-Rings, Young Bae Jun, Mehmet Sapanci, Mehmet Ali̇ Öztürk

Turkish Journal of Mathematics

The aim of this paper is to introduce the notion of fuzzy left (resp. right) ideals of \Gamma-near-rings, and to study the related properties.


A Berry-Esseen Bound For Empty Boxes Statistic On The Scheme An Allocations Of Several Type Balls, S.A. Mirakhmedov, O. Saidova Jan 1998

A Berry-Esseen Bound For Empty Boxes Statistic On The Scheme An Allocations Of Several Type Balls, S.A. Mirakhmedov, O. Saidova

Turkish Journal of Mathematics

A Berry-Esseen bound for the number of empty cells in the scheme of independent and random allocation of balls of $s$ type into different cells is obtained.


Finite Direct Sums Of (D1)-Modules, Derya Keskin Jan 1998

Finite Direct Sums Of (D1)-Modules, Derya Keskin

Turkish Journal of Mathematics

In this paper we give necessary conditions for a finite direct sum of (D1)--modules to be a (D1)--module.


On Derived Equivalences And Local Structure Of Blocks Of Finite Groups, Markus Linckelmann Jan 1998

On Derived Equivalences And Local Structure Of Blocks Of Finite Groups, Markus Linckelmann

Turkish Journal of Mathematics

No abstract provided.


Crossed N-Cubes And N-Crossed Complexes Of Commutative Algebras, Z. Arvasi̇, M. Koçak Jan 1998

Crossed N-Cubes And N-Crossed Complexes Of Commutative Algebras, Z. Arvasi̇, M. Koçak

Turkish Journal of Mathematics

In this paper we will define crossed $\Bbb N$-cubes and n-crossed complexes of commutative algebras and construct a functor from the category of simplicial algebras to that of n-crossed complexes.


Pullbacks Of Crossed Modules And Cat^1-Groups, Murat Alp Jan 1998

Pullbacks Of Crossed Modules And Cat^1-Groups, Murat Alp

Turkish Journal of Mathematics

In this paper, wer define the pullback cat$^{1}$-groups and we showed that the category of bullback cat$^{1}$-group is equivalent to the category of pullback crossed modules. 1991 A. M. S. C.: 13D99, 16A99, 17B99, 18D35.


Derivation Of Separable Amplitude Equations By Multiple Scales Method, Mehmet Naci̇ Özer, Dursun Eser Jan 1998

Derivation Of Separable Amplitude Equations By Multiple Scales Method, Mehmet Naci̇ Özer, Dursun Eser

Turkish Journal of Mathematics

The method of multiple scales is used to derive separable nonlinear Schrödinger equations as amplitude equation from three component 2D nonlinear Klein-Gordon Equation. We further discuss the integrability of the derived separable amplitude equations and reduce them into finite dimensional Hamiltonian systems. Finally we give first integrals for the reduced systems.


The Dual Of The Bochner Space L^P(\Mu,E) For Arbitrary \Mu, Bahatti̇n Cengi̇z Jan 1998

The Dual Of The Bochner Space L^P(\Mu,E) For Arbitrary \Mu, Bahatti̇n Cengi̇z

Turkish Journal of Mathematics

Let $\mu$ be a finite measure, $E$ a Banach space, and $1\leq p


Direct Sums And The Schur Property, Betül Tanbay Jan 1998

Direct Sums And The Schur Property, Betül Tanbay

Turkish Journal of Mathematics

It is a known fact that $\ell^1$, the dual space of the null sequences $c_0$, has the Schur property, that is, weakly convergent sequences in $\ell^1$ are norm convergent. In this paper, we prove that if $(X_{\alpha})_{\alpha\in I}$ are Banach spaces and $X=(\oplus_{\alpha\in I}X_{\alpha})_1$ their $l_1$-sum, then the space $X$ has the Schur property iff each factor $X_{\alpha}$ has it.


Hazardous Waste Determination And Government Enforcement Actions In The Resource Conservation And Recovery Act And The Law No. 24051: Comparison Between The United States And Argentina, Eduardo Jose Conghos Jan 1998

Hazardous Waste Determination And Government Enforcement Actions In The Resource Conservation And Recovery Act And The Law No. 24051: Comparison Between The United States And Argentina, Eduardo Jose Conghos

LLM Theses and Essays

The incremental generation and disposal of hazardous waste, causing severe environmental pollution, has become one the world’s most important ecological problems starting with the Stockholm Conference in 1972. This paper examines two legislative reactions to pollution caused by hazardous wastes in the United States, under the Resource Conservation and Recovery Act 1976 (RCRA), and Argentina, in Law No. 24051. This paper makes a comparative analysis of the material provisions of both the RCRA and the Law with emphasis on the tools and actions provided for the enforcement of the RCRA and the Law. The paper concludes that the RCRA and …