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1998

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Articles 2281 - 2310 of 2574

Full-Text Articles in Physical Sciences and Mathematics

A Framework For Planning Sustainable Development In Coastal Regions: An Island Pilot Project In Croatia, Anamarija Frankic Jan 1998

A Framework For Planning Sustainable Development In Coastal Regions: An Island Pilot Project In Croatia, Anamarija Frankic

Dissertations, Theses, and Masters Projects

There have been few empirical studies demonstrating how sustainable development has been realized in a specific regime. This project developed and tested a framework for comprehensive planning including environmental, social, and economic considerations on the island Cres in the Croatian Coastal Zone. The approach defines sustainable development in coastal regions, and develops a generic framework incorporating biological, geological, chemical, physical, social, and economic factors necessary for sustainable development. The generic framework ensures that planning decisions will be based on environmental concerns of the area. A prime principle of the approach is that any plan must work with the environmental limits …


Distribution, Partitioning And Fluxes Of Dissolved And Particulate Organic Carbon, Nitrogen And Phosphorus In The Eastern North Pacific And Southern Oceans, Ai Ning Loh Jan 1998

Distribution, Partitioning And Fluxes Of Dissolved And Particulate Organic Carbon, Nitrogen And Phosphorus In The Eastern North Pacific And Southern Oceans, Ai Ning Loh

Dissertations, Theses, and Masters Projects

No abstract provided.


Calcium As A Limiting Factor In The Distribution Of The Amphipod Gammarus Pseudolimnaeus, John Kinsley Zehmer Jan 1998

Calcium As A Limiting Factor In The Distribution Of The Amphipod Gammarus Pseudolimnaeus, John Kinsley Zehmer

Dissertations, Theses, and Masters Projects

No abstract provided.


Selective Selenoxide Elimination On The Secondary Face Of Beta-Cyclodextrin, Ahmed M. Hafez Jan 1998

Selective Selenoxide Elimination On The Secondary Face Of Beta-Cyclodextrin, Ahmed M. Hafez

Dissertations, Theses, and Masters Projects

No abstract provided.


Frequency Modulated Excitation Of A Two-Level Atom, Michael W. Noel, W. M. Griffith, T. F. Gallagher Jan 1998

Frequency Modulated Excitation Of A Two-Level Atom, Michael W. Noel, W. M. Griffith, T. F. Gallagher

Physics Faculty Research and Scholarship

We present a detailed experimental study of the frequency-modulated excitation of a two-level atom, using a microwave field to drive transitions between two Rydberg Stark states of potassium. In the absence of a modulation the interaction is the standard model of the Rabi problem, producing sinusoidal oscillations of the population between the two states. In the presence of a frequency modulation of the interacting field, however, the time evolution of the system is significantly modified, producing square wave oscillations of the popula- tion, sinusoidal oscillations at a different frequency, or even sinusoidal oscillations built up in a series of stair …


1998 Southeast Nebraska Tallgrass Praire Inventory: Johnson, Gage, And Jefferson Counties, Final Report, Robert F. Steinauer Jan 1998

1998 Southeast Nebraska Tallgrass Praire Inventory: Johnson, Gage, And Jefferson Counties, Final Report, Robert F. Steinauer

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

This report is prepared as a requirement of the 1998 Southeast Nebraska Prairie Survey contract between the Platte/Rainwater Basin Project Office of the Nature Conservancy and Robert F. Steinauer. The original contract called for the examination of Johnson County south of Highway 136, and Gage County east of Beatrice. Due to the scarcity of prairies in these areas, the survey region was expanded to include northern Johnson County, and southern Jefferson County.

Prairies in these areas were identified using infrared and black and white photos, driving on county and within grassland roads, and conversations with landowners. Heritage Program “Site Survey …


The Role Of The Einstein Library Of Nova Southeastern University In Meeting The Needs Of Distance Education Students, Anne K. Abate Jan 1998

The Role Of The Einstein Library Of Nova Southeastern University In Meeting The Needs Of Distance Education Students, Anne K. Abate

CCE Theses and Dissertations

The goal of this study was to evaluate the information needs of a selected segment of the distance learning graduate student population served by the Einstein Library at Nova Southeastern University and to propose a new model of library service based on the implementation of current and emerging technologies. Several survey instruments were developed and administered through electronic mail to students and faculty in the School of Computer and Information Sciences, the Center for Psychological Studies, and the School of Social and Systemic Studies, the Fischler Center for the Advancement of Education and the School of Business and Entrepreneurship at …


Strategy Building Session For Wirenet For The City Of Cleveland West Side Economic Development Initiative: Site Prioritization And Selection, Kirstin Toth, Donald T. Iannone Jan 1998

Strategy Building Session For Wirenet For The City Of Cleveland West Side Economic Development Initiative: Site Prioritization And Selection, Kirstin Toth, Donald T. Iannone

All Maxine Goodman Levin School of Urban Affairs Publications

No abstract provided.


Effect Of Electronic Portfolio Assessments On The Motivation And Computer Interest Of Fourth And Fifth Grade Students In A Massachusetts Suburban School, Paul V. Montesino Jan 1998

Effect Of Electronic Portfolio Assessments On The Motivation And Computer Interest Of Fourth And Fifth Grade Students In A Massachusetts Suburban School, Paul V. Montesino

CCE Theses and Dissertations

A preliminary causal-comparative study was conducted in an elementary suburban school in Massachusetts to investigate the impact of electronic portfolio assessments in student's intrinsic motivation and computer interest.

The target population were two groups of fourth grade and two groups of fifth grade students for a total of 77 subjects. They were trained and introduced to electronic portfolio assessments, a program which lasted for the entire school year. The students used Hyper Studio, a multimedia software program developed and marketed by Roger Wagner Publishing, Inc.

It was the intention of the elementary school program directors and teachers that students would …


A Simplified Faceted Approach To Information Retrieval For Reusable Software Classification, Victor Allen Nguyen Jan 1998

A Simplified Faceted Approach To Information Retrieval For Reusable Software Classification, Victor Allen Nguyen

CCE Theses and Dissertations

Software Reuse is widely recognized as the most promising technique presently available in reducing the cost of software production. It is the adaptation or incorporation of previously developed software components, designs or other software-related artifacts (i.e. test plans) into new software or software development regimes. Researchers and vendors are doubling their efforts and devoting their time primarily to the topic of software reuse. Most have focused on mechanisms to construct reusable software but few have focused on the problem of discovering components or designs to meet specific needs. In order for software reuse to be successful, it must be perceived …


A Transaction Model For Mobile Computing, Sanjay Kumar Madria, Bharat Bhargava Jan 1998

A Transaction Model For Mobile Computing, Sanjay Kumar Madria, Bharat Bhargava

Computer Science Faculty Research & Creative Works

We introduce a prewrite operation before a write operation in a mobile transaction to improve data availability. A prewrite operation does not update the state of a data object but only makes visible the value that the data object will have after the commit of the transaction. Once the transaction has read all the values and declares all the prewrites, it can precommit at a mobile host. The remaining transaction's execution is shifted to the stationary host. Writes on a database consume both time and resources at the stationary host and are therefore delayed. A pre-committed transaction's prewrite values are …


On The Structure Of Graphs With Few P4s, Luitpold Babel, Stephan Olariu Jan 1998

On The Structure Of Graphs With Few P4s, Luitpold Babel, Stephan Olariu

Computer Science Faculty Publications

We present new classes of graphs for which the isomorphism problem can be solved in polynomial time. These graphs are characterized by containing — in some local sense — only a small number of induced paths of length three. As it turns out, every such graph has a unique tree representation: the internal nodes correspond to three types of graph operations, while the leaves are basic graphs with a simple structure. The paper extends and generalizes known results about cographs, P4-reducible graphs, and P4-sparse graphs.


Daniel Wolfman, 1939-1994, Izumi Shimada Jan 1998

Daniel Wolfman, 1939-1994, Izumi Shimada

Andean Past

No abstract provided.


The Jampatilla Obsidian Source: Identifying The Geological Source Of Pampas Type Obsidian Artifacts From Southern Peru, Richard L. Burger, Katharina J. Schreiber, Michael D. Glascock, Jose Ccencho Jan 1998

The Jampatilla Obsidian Source: Identifying The Geological Source Of Pampas Type Obsidian Artifacts From Southern Peru, Richard L. Burger, Katharina J. Schreiber, Michael D. Glascock, Jose Ccencho

Andean Past

No abstract provided.


Archaeomagnetic Results From Peru: A.D. 700-1500, Daniel Wolfman, Richard E. Dodson Jan 1998

Archaeomagnetic Results From Peru: A.D. 700-1500, Daniel Wolfman, Richard E. Dodson

Andean Past

No abstract provided.


A Time-Dependent Quantum Study Of Li+Hf(\Nu=1) -> Lif(\Nu')+H, Fahrettin Gögtaş, Gabriel G. Balint-Kurti Jan 1998

A Time-Dependent Quantum Study Of Li+Hf(\Nu=1) -> Lif(\Nu')+H, Fahrettin Gögtaş, Gabriel G. Balint-Kurti

Turkish Journal of Physics

Time-dependent quantum wave packet calculations are performed for a model based (two-dimensional) $Li+HF(\nu=1)\ra LiF(\nu^{\prime})+H$ reaction. The reaction probabilities for a broad range of collison energies are calculated by a single solution of the time-dependent Schr\\"{o}dinger equation. The calculated reaction probabilities show many sharp features as a function of energy which are ascribed to scattering resonances.


Alpha Particle Fragments Produced From Multifragmentation Of ^{16}O+^{16}O, M.Y.H. Farag Jan 1998

Alpha Particle Fragments Produced From Multifragmentation Of ^{16}O+^{16}O, M.Y.H. Farag

Turkish Journal of Physics

Angular distribution for alpha particles produced from multifragmentation of ^{16}O + ^{16}O reactions are calculated using the statistical scission model. The alpha particles are sequentially emitted from long lived states of primary fragments populated in these reactions. Eight alpha particles are produced in these reactions. The calculations are carried out for different energies and for different nuclear temperatures. The variances of this multifragmentation process have been numerically calculated. The obtained results are in good agreement with previous calculations.


Thermodynamics And Structure Of Simple Liquid Metals Calculated Using An Analytic Pair Potential, Serap Dalgiç, Seyfettin Dalgiç, M. Tomak Jan 1998

Thermodynamics And Structure Of Simple Liquid Metals Calculated Using An Analytic Pair Potential, Serap Dalgiç, Seyfettin Dalgiç, M. Tomak

Turkish Journal of Physics

The analytic interatomic pair potential for simple metals is derived from first principles using second order pseudopotential theory by Pettifor and Ward . It is developed using the Heine-Abarenkov pseudopotential for simple metals and applied to the calculations of the structural and thermodynamic properties of liquid metals. The corresponding liquid metal structure is calculated using the random phase approximation and the hypernetted-chain formulation. The long-wavelength limit S(0) of the structure factor of liquid metals using the hard-sphere system as reference is also investigated. The calculated thermodynamic and structural properties using the real space formalism are in better agreement with experimental …


A Study On The Effect Of Ni Dopping On Bi-Pb-Sr-Ca-Cu-O System, M. Tepe, D. Abukay Jan 1998

A Study On The Effect Of Ni Dopping On Bi-Pb-Sr-Ca-Cu-O System, M. Tepe, D. Abukay

Turkish Journal of Physics

The effect of $Ni$ doping on superconductivity properties of the $Bi_{1.7}Pb_{0.3}Sr_2Ca_2(Cu_{1-x}Ni_x)_3O_y$ system has been investigated by means of $x$-ray diffraction, ac electrical resistance, ac magnetic susceptibility and critical current measurements. The volume fraction of the 2223 phase decreases with increasing $Ni$ concentration. The zero-resistance temperature and the critical current density are suppressed with $Ni$ substitution.


Characterization Of Sb Doped Y Bacuo Superconducting Ceramics, K. Kocabaş, N. Kazanci, M. Tepe Jan 1998

Characterization Of Sb Doped Y Bacuo Superconducting Ceramics, K. Kocabaş, N. Kazanci, M. Tepe

Turkish Journal of Physics

In this study the structural characteristics of $Sb_2O_3$ doped $YBa_2Cu_3O_{7-x}$ superconductive ceramics are investigated by electrical and XRD analyses. It is determined that, while in undoped specimens the value of $T_c$ is equal to 92 K, this value is negatively influenced by the addition of $Sb$. Structural phase results obtained from XRD analysis confirm the result obtained from the electrical measurements.


Microscopic Calculations Of The Nucleus-Nucleus Optical Potential, M. M. Osman Jan 1998

Microscopic Calculations Of The Nucleus-Nucleus Optical Potential, M. M. Osman

Turkish Journal of Physics

In present work, a density dependent nucleon-nucleon interactions based on the $G$-matrix elements of the Paris nucleon-nucleon potential have been used to calculate the real part of the nucleus-nucleus optical potential. We have compared our results with those deduced from experiment. We found that our results, obtained using a suitable approximation of the kinetic energy density, agree satisfactory with those extracted from experiment at the strong absorption radius. Moreover, the higher values of the compressibility, $K$, agree better with experiment than the lower values.


Deformation Methods For Investigation Of The Deep Level Parameters In Semiconductors, S. Z. Zainabidinov, A. Abduraimov, O. O. Mamatkarimov, I.G. Tursunov, R.Kh. Khamidov Jan 1998

Deformation Methods For Investigation Of The Deep Level Parameters In Semiconductors, S. Z. Zainabidinov, A. Abduraimov, O. O. Mamatkarimov, I.G. Tursunov, R.Kh. Khamidov

Turkish Journal of Physics

In this paper deformation methods are offered to investigate deep level parameters in semiconductors. It is based on strain parameters measurements of compensated and overcompensated semiconductors. The dynamic changes of current flow in compensated and overcompensated samples of $p$-type $Si: Ni$ and $n$-type $Si: Mn$ under uniform pulse hydrostatic compression (UHC) was investigated. It was observed that in $p$-type $Si: Ni$ samples ionization energy levels $Ni$ at UHC increases, on the contrary in samples $n$-type $Si: Mn$ it decreases. The ionization energy and baric coefficient of the shift of $Ni$ and $Mn$ levels were bounded.


Interrelation Of Magnetic Properties With The Crystal Structures Of Mefese (Me = Ti; V; Cr; Fe; Co; Ni) Compounds, R. Sadikhov, A. Namazov, J. Guseinov Jan 1998

Interrelation Of Magnetic Properties With The Crystal Structures Of Mefese (Me = Ti; V; Cr; Fe; Co; Ni) Compounds, R. Sadikhov, A. Namazov, J. Guseinov

Turkish Journal of Physics

Magnetization of MeFe$_2$Se$_4$ (Me = Ti; V; Cr; Fe; Co; Ni) compounds at low temperatures has been investigated. It is shown that these compounds are ferrimagnetics with low values of specific magnetization. It is established that along the crystal axis $c$ of a given compound, there have been carried out two types of exchange interactions; cation-cation and cation-anion-cation with different dependence of their quantity on interatomic distance.


Modelling Of Radiation Regime Receiver Cavities Of Solar Power Plants, Eduard Avanesov, Nina Berezhnaya Jan 1998

Modelling Of Radiation Regime Receiver Cavities Of Solar Power Plants, Eduard Avanesov, Nina Berezhnaya

Turkish Journal of Physics

In this work, we develop a model for radiant heat transfer calculations inside spherical and cylindrical spaces. The analysis of the possibility of mirror cone subreflector applications for uniform flux density attainment is carried out. A procedure optimizing equiilluminate space forming a search for an indicatrix's composition is developed.


Electro-Optic Response Of A Polymer Dispersed Liquid Crystal Film, Rıdvan Karapinar Jan 1998

Electro-Optic Response Of A Polymer Dispersed Liquid Crystal Film, Rıdvan Karapinar

Turkish Journal of Physics

Polymer dispersed liquid crystal (PDLC) films are potentially useful in electro-optic devices since they can be used for vision products. In this work the PDLC thin films were prepared by a photopolymerization induced phase separation method and electro-optic properties of the films were investigated.


Reorientation Of Magnetization In Thin Films, Bengü Kaplan Jan 1998

Reorientation Of Magnetization In Thin Films, Bengü Kaplan

Turkish Journal of Physics

The spin wave energy is determined by the competition between uniaxial and cubic anisotropy. We discuss the reorientation temperature $ T_{R} $ of magnetization in two-dimension and calculate its dependence on the exchange, $J$, and the uniaxial anisotropy, $G$, parameters within random phase approximation. We find that $ T_{R} $ varies as $ \sqrt{JG} $ in the planar regime.


Studies Of Structure Of Ceramic Materials Containing Molibdenum Particles Within The Framework Of Theory Of Non-Homogeneous Systems, Sh. Kami̇lov, M. Karabaeva, U. Abdurahmanov Jan 1998

Studies Of Structure Of Ceramic Materials Containing Molibdenum Particles Within The Framework Of Theory Of Non-Homogeneous Systems, Sh. Kami̇lov, M. Karabaeva, U. Abdurahmanov

Turkish Journal of Physics

The structure of ceramic materials containing molibdenum powder is considered within the framework of leakage theory. Determined are the density of the endless cluster, volumetric parts of the skeleton and dead ends, as well as their dependence on the component concentration. Volumetric part of the skeleton near the threshold of leakage makes a negligible part of the full volume.


The Influence Of Solvents On Formation Of The Molecular Geometry Of [{Fe(Salphen)}_2o], Mehmet Kabak, Ayhan Elmali Jan 1998

The Influence Of Solvents On Formation Of The Molecular Geometry Of [{Fe(Salphen)}_2o], Mehmet Kabak, Ayhan Elmali

Turkish Journal of Physics

The crystal structure and magnetic properties of the complex (I)=[$\{$Fe(salphen)$\}_2$\-O]$\cdot$(C$_4$\-H$_8$SO) and (II)=[$\{$Fe(salphen)$\}_2$O]$\cdot$(C$_4$H$_8$O$_2$)\- (salphen H$_2$=N,N'-o-phenylenebis\-(salicylidene-imine)) were recently reported [1, 2]. This complex crystallized with the solvents of dimethyl sulfoxide and dioxane. In this paper, we investigate the influence of the solvents on the formation of the molecular geometry and study the orbital mechanism of the magnetic super-exchange interactions of this complex.


Delay Time Fluctuations Of The Tunnel Josephson Junction In The Case Of Linearly Growing Current, Iman Novruzoglu Askerzade Jan 1998

Delay Time Fluctuations Of The Tunnel Josephson Junction In The Case Of Linearly Growing Current, Iman Novruzoglu Askerzade

Turkish Journal of Physics

Delay time thermal fluctuations intensity of the tunnel Josephson junction for the case of high current rate is calculated.


A New Probe Head Design For The Weak Field Double Resonance Spectrometer, A. Oral Salman, M. Maral Sünnetçi̇oğlu, Rıza Sungur, Gökçe Bi̇ngöl Jan 1998

A New Probe Head Design For The Weak Field Double Resonance Spectrometer, A. Oral Salman, M. Maral Sünnetçi̇oğlu, Rıza Sungur, Gökçe Bi̇ngöl

Turkish Journal of Physics

In order to observe low field $\sigma$ EPR spectra of free radicals a new probe head was designed to work at 1.53 mT. As a double resonance spectrometer, at 1.53 mT the probe head includes both NMR and EPR rf coils. To induce the $\sigma$ transitions EPR rf coil must produce an rf field parallel to the main static field. Various coil designs were examined for this aim and the best results was obtained with a solenoid NMR coil and saddle shaped single turn EPR coil design combination.