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Eects Of Post Deposition Treatments On Vacuum Evaporated Cdte Thin Films And Cds=Cdte Heterojunction Devices, Habibe Bayhan, Çiğdem Erçelebi̇

Turkish Journal of Physics

$CdTe, CdS$ thin films and $n-CdS/p-CdTe$ heterostructures have been prepared by conventional vacuum evaporation technique. Some post deposition treatments to optimize the device efficiency have been analyzed and the effects of the individual process steps on the material and device properties were investigated. Annealing in air with and without $CdCl_2$-treatment decreased the $CdTe$ resistivity. The $CdCl_2$-dip followed by annealing in air at $300^{\circ}C$ for 5 min improved the grain size and polycrystalline nature of $CdTe$ thin films. Solar efficiency improvements were achieved when heterojunctions were prepared on successively treated (i.e. etched, air annealed, $CdCl_2$-processed) $CdTe$ surfaces. Etching of the $CdTe$ …

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.

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

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.

Characterization Of Spray Deposited Bismuth Oxide Thin Films From Non-Aqueous Medium, V.V. Killedar, C.H. Bhosale, C.D. Lokhande

Turkish Journal of Physics

Bismuth oxide thin films have been prepared on amorphous glass substrates from non-aqueous medium using spray pyrolysis method. Characterization of the films was carried out with XRD, optical absorption, dark resistivity and thermoelectric power (TEP) measurements. These studies reveal that films as deposited are polycrystalline; having an optical band gap of 2.6 eV; electrical resistivity is of the order of $10^6$ ohm-cm; and electron carrier concentration and mobility are of the order of $3.8 \times 10^{19}$cm$^3$ and $1.5 \times 10^{-4}$cm$^2$ V$^{-1}$s$^{-1}$, respectively.

Analysis Of Atmospheric Concentrations Of Radon And Thoron Using Beta Counting Technique, G. S. Islam, S. M. Basunia

Turkish Journal of Physics

This paper presents a detailed theory and experimental procedure for measurement and analysis of mixed radon and thoron in the environment. The technique has been successfully applied to the study of seasonal variations of radon and thoron in the atmosphere around Rajshahi, Banladesh, during the years 1989-1991. The maximum radon concentration in outdoor air was observed in the winter from December to January while the indoor radon concentration was found to be maximum during the monsoon months of July and August. The implication of the results is briefly discussed in the paper.

A Study Of Heavy-Ion Elastic Scattering Reactions Using A Semimicroscopic Model, A. A. Farra

Turkish Journal of Physics

The differential cross sections for elastic scattering of ^{16}O from ^{20}Ne have been calculated using an optical potential and distorted wave Born approximation (DWBA) calculations. In the present calculations several prescriptions were tried in the ion-ion potential. The DWBA calculations were performed employing folded real and Woods-Saxon optical potentials for the distorted waves. Inclusion of the exchange process explains the large back-angle cross sections. The elastic scattering differential cross sections are successfully described by calculations in which elastic alpha-transfer amplitudes are coherently added to direct elastic scattering amplitudes.

Effect Of Deposition Conditions On Composition Of Rf-Sputtered Bi-Sr-Ca-Cu-O Thin Films, Ayhan Güldeste

Turkish Journal of Physics

The effect of rf-magnetron sputtering conditions on as-deposited film composition using a stoichiometric Bi_2Sr_2CaCu_2O_y (Bi-2212) target was investigated in an on-axis configuration, as the stoichiometrical control of the film is the most important parameter for the proper study of film characteristics. It was found that substrate target distance up to 55-60 mm may provide a film composition close to the target composition. The sputtering chamber pressure effecting film composition, especially in respect of Bi, is an important parameter which needs very pracise control. Bi ratio in the deposited films increases with increasing Ar pressure while Sr and Ca are not …

Flavour Violating \Tau-Decays In Magnetic Interaction And E_6 Models, A.T. Alan, Z.Z. Aydin And S. Sultansoy

Turkish Journal of Physics

In the view of future c-\tau-factories, we report an analysis of the rare decays of the \tau lepton via \tau \to \mu e \overline{e}, \tau \to e \mu \overline{\mu}, \tau \to \mu \mu \overline{\mu} and \tau \to ee \overline{e} in the two models, i.e., in Barut's magnetic interaction model (MIM) and in an E_6 model proposed by Gürsey and his collaborators. The energy distributions of one of the final leptons are given for both models. Numerical estimates reveal that these decays can be as large as 10^{-6}, which may be observed in LEP experiments or at other c-\tau factories.

Quantum Integrable Systems Of The Group Su(1, 1), Mehmet Sezgi̇n, Yılmaz Asad Verdi̇yev

Turkish Journal of Physics

Quantum integrable systems related with SU(1, 1) group manifold or hyperboloid [x, x] = x^2_1 + x^2_2 - x^2_3 - x^2_4 = 1 in spherical, hyperbolic and parabolic coordinates systems are considered. The explicit expressions for waves functions, spectra and S-matrices are given.

Cover And Contents

Turkish Journal of Physics

No abstract provided.

Acceleration Policies And Practices In Central Iowa, Patricia Ann Smith

Graduate Research Papers

This study explored acceleration practices throughout the country with a focus on the public and private schools of Area Education Agency (AEA) 11 in Central Iowa. Questions explored included the following: Do the school districts and private schools in AEA 11 allow for the academic acceleration of students in any form? Do they have written or implied unwritten policies for acceleration? What practices, if any, are currently employed by AEA 11 schools? What percentage of students in these schools engage in each type of acceleration? What criteria are used to select students for acceleration? How many acceleration experiences have had …

Integrating Children's Literature And Mathematics In The Early Childhood Classroom, Jamie M. Christensen

Graduate Research Papers

"Historically there have been three reasons for groups to formally adopt a set of standards: (1) to ensure quality, (2) to indicate goals, and (3) to promote change. For NCTM, all three reasons are of equal importance" (The National Council of Teachers of Mathematics, 1989, p. 2).

Now, more than any other time in history, mathematical reform is essential in our school systems. The traditional mathematics curriculum was designed to prepare shopkeepers, farmers, and factory workers for occupations in the early 1900s. Some of those skills are still useful in today's society. However, as the new millennium approaches, our future …

Copyright Issues For The Technological Classroom : What Is Permissible Under Current Copyright Law And Guidelines For Educators In The Design And Use Of Multimedia, Disance Learning, And Other Recent Technological Advances?, Anthony Kenneth Clark

Graduate Research Papers

Technologies, such as computers, Internet, electronic mail etc., offer educational institutions limitless opportunities for learning and teaching. While technological advancements encourage academia to boldly go where no one has gone before, there are legitimate copyright and intellectual property concerns that need to be addressed. The current copyright law passed in 1976, although it legally established the Fair Use principle, is inadequate given the age we live in.

To encourage dialogue, this review of the literature will explore the applicability of copyright law to educators in the electronic environment. Current law, established guidelines, and recent court decisions will be discussed in …

Integration Of Technology Into Science Education, Paul Zahner

Graduate Research Papers

In this paper, the importance of integrating technology into science education is discussed. The correlation between technology and science is noted and national science standards are examined. The evolution of today's learners requires a change in science education, and technology can serve as a vehicle for meaningful reform. The starting point for any change in science education lies with the teacher, who must adopt new strategies to meet the needs of all types of learners. Various examples of these teaching plans are discussed within this paper. Other important components of the change process include school administration support, especially financial. These …

Cluster Grouping Elementary Gifted Students In The Regular Classroom: A Teacher's Perspective, Kevin Michael Teno

Graduate Research Papers

Cluster grouping is a programming option that is receiving increased attention as a method of serving gifted students in regular heterogeneously grouped classrooms. This article provides an overview of the literature on cluster grouping and also examines the advantages and disadvantages of clustering from the perspective of conclusions obtained through actual implementation in an elementary school district. The conclusions indicate that clustering, if carefully planned and implemented, provides a viable option in meeting the needs of gifted students and improves the education of all students in the regular classroom.

Cover And Contents

Turkish Journal of Biology

No abstract provided.

Cover And Contents

Turkish Journal of Biology

No abstract provided.

Object-Oriented Computer Simulations Of Physical Systems Using Dual Reciprocity Boundary Element Methodology, J. Friedrich

Turkish Journal of Electrical Engineering and Computer Sciences

Models of physical systems are essential in every engineering field. This work deals with computer simulations of physical systems that can be mathematically modelled by differential equations together with sufficient boundary conditions. The computer simulations are based on object-oriented technology and the dual reciprocity boundary element method which is a universal solution scheme for various types of partial differential equations (e.g. Laplace, Poisson, diffusion, convection-diffusion, and steady Navier-Stokes equation). This technique fulfills efficiency criteria like precision, robustness, versatility, programmability, user-friendliness, need of computational time and computer memory to a very high degree. This is demonstrated by three examples: Laplace's solution …

Distribution System Planning Usign Mixed Integer Programming, Belgin Türkay

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents an improved mathematical model to optimise the size and locations of substations and the network routing problem. The model was formulated to minimise the total cost of the network by determining the optima of the substation locations and power, the load transfers between the demand centers, the feeder routes and the load flow in the network subject to a set of constraints. The computational results of a devised sample problem indicate that the developed optimisation model and its code are adequate for computer aided planning of distribution systems.

Analysis Of Nonlinear Sustained Oscillations In Discrete Systems With Backlash And Resolution By Using A Discretization-Oriented Describing Function, M. De La Sen, A. Pena, J. Esnaola

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a discretization-oriented describing function is derived for nonlinear devices combining backlash and quantization (resolution) while being subject to discretization through a sampler and zero-order hold. Such a describing function is frequency-dependent so that the overall nonlinearity, which includes both resolution and backlash, is interpreted as possessing nonlinear inertia. That nonlinear inertia is generated by the sampling process, since it does not appear if the system is continuous. The presence of nonlinear sustained oscillations (limit cycles) is investigated through simulations.

Cover And Contents

Turkish Journal of Electrical Engineering and Computer Sciences

No abstract provided.

Signal Injection With Perceptual Criteria, T. Engi̇n Tuncer

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a novel method for increasing the coding performance and information transmission capacity is presented. This method is mainly based on perceptual modelling of input signal such as speech or audio. Presented approach may be seen as an alternative to transforms which dynamically change analysis window for better energy compaction. A perceptual model is established in order to obtain a global masking threshold in frequency below which sounds become inaudible. Certain criteria are developed for identifying the signal injection bands. A new multiband filter design method which is a generalization of windowing method is used to separate the …

State Of Art In Realistic Head Modeling For Electro-Magnetic Source Imaging Of The Human Brain, Nevzat G. Gençer, İ. Oğuz Tanzer, M. Kemal Özdemi̇r, Can E. Acar, Mert Sungur

Turkish Journal of Electrical Engineering and Computer Sciences

Electric currents produced by the neural activity in the brain create electric potentials on the scalp and magnetic field distribution outside the scalp. Measuring electric and magnetic fields provides a means to understand the spatio-temporal distribution of the neural activity. The representations of the intracellular electric current of active cell populations based on bimodal data are called electro-magnetic source image (EMSI). With the recent development of large arrays of magnetic sensors, and systems for measuring scalp voltages at more than 100 locations, it is now feasible to implement computational methods that employ numerical models which incorporate the correct geometry and …

Cover And Contents

Turkish Journal of Electrical Engineering and Computer Sciences

No abstract provided.

Books ‘N Kids On-Line: An On-Line Book Club, Pamela J. Martin

Graduate Research Papers

The purpose of this project is to create an On-line book club for 4th and 5th grade elementary students that will encourage them to read and interact with other members regarding their thoughts and feelings about particular books. This project, Books 'n Kids On-line, will integrate the reading, writing, and sharing elements of a book club with On-line Web communication.

7. Thermal Diagenesis Of Cretaceous Sediment Recovered At The Cote D’Ivoire – Ghana Transform Margin, Mary Anne Holmes

Department of Earth and Atmospheric Sciences: Faculty Publications

The early opening of the South Atlantic ocean along the eastern Romanche Fracture Zone, including an initial phase of transform faulting and pull-apart basin formation, followed by the generation of a seafloor spreading center, was investigated during Ocean Drilling Program Leg 159 to the Côte d’Ivoire-Ghana continental margin. Clay minerals in the <0.5-μm fraction of tectonically disturbed sediment recovered during this leg were analyzed by X-ray diffraction to determine the extent of thermal diagenesis caused by the passing of the South Atlantic spreading center along this transform margin, and to date the passing. Results from Sites 959-961 reveal mild thermal alteration of clays, to paleotemperatures of 120°–170°C, in older, mostly undated sediment, in response to an elevated paleogeothermal gradient, as indicated by the absence of randomly interstratified illite/smectite group clays (R = 0 I/S clay), and the presence of dominant regularly interstratified (R = 1) I/S clay. Thermally altered sediment at these sites underlie unaltered sediment with likely erosional contacts. Based on a date of nannofossil biozone CC9b for the oldest unaltered sediment at Site 959, the thermal event there must have been pre-CC9b.
At Site 962, drilled on a minor marginal ridge to the west of Sites 959–961, heat has altered clay in basal sediment to R = 1 I/S, and the transition uphole to thermally unaltered sediment, bearing R = 0 I/S clay, was recovered over a 175-m-thick interval, indicating …

University Reporter - Vol. 02, No. 05 - January 1998 - Calendar Of Events, University Of Massachusetts Boston

1996-2009, University Reporter

No abstract provided.

Insights- July 1998, University Relations Staff

Insights

No abstract provided.

Northeastern News- Winter 1998, Lisa D. Cooper

NEIU News

No abstract provided.