Physical Sciences and Mathematics Commons^™

Preparation And Anisotropic Elastic Property Of Bi-Sr-Ca-Cu-O Whiskers, Khaliq A. Chaudhary, M. Arshad Choudhry

Turkish Journal of Physics

Flexible and superconducting Bi-Sr-Ca-Cu-O whiskers have been prepared by sintering the melt-quenched glassy powder at 830^oC in oxygen atmosphere. X-ray diffraction and a.c. susceptibility measurements reveal that the whiskers belong to 2212 phase with T_{c} = 79k. The whiskers possess high strength and flexibility along c-axis but were found to be weak and brittle when bent normal to the c-axis. The anisotropic micromechanical elastic property of the whiskers have been demonstrated under a low power optical microscope.

Radial And Nonradial Oscillations Of 63 Her (Hd155514 = Hr6391), Ri̇kkat Ci̇velek, Ni̇lgün Kiziloğlu, Hali̇l Kirbiyik

Turkish Journal of Physics

An attempt has been made toward explaining the observed frequencies in 63 Her. A sequence of evolutionary models have been calculated up to a point where stellar parameters match the observed luminosity and effective temperature of 63 Her. Radial and nonradial oscillations frequencies were obtained for a series of masses 1.85, 1.90 and 1.95 M_\odot and eigth models which represent best the pulsations of 63 Her are given in this paper. Calculations are restricted to low harmonic degrees ( l= 0,1,2,3 ). Six of the eigth observed frequencies quoted in literature were obtained. These we obtained for the model of …

Tsl-Epr Correlation Study Of Lapo_4 : Ce, Tb, B. S. Chakrabarty, K. V. R. Murthy, T. R. Joshi

Turkish Journal of Physics

Gamma irradiated TSL glow curves of laboratory made phosphor samples of LaPO_{4}:Ce, Tb exhibited one intense peak around 408 K and two smaller peaks around 508 K and 613 K. The spectrum of the first glow peak gives spectral peaks around 480 nm and 540 nm, which can be attributed to the thermal destruction of F^{++} centres and PO_4^{2-} radicals. The luminescense centre has been thought to be Cerium and Terbium ions. The glow peak around 413 K for UV irradiated samples has been attributed to aggregates of dopant ions. The photoluminescence study of the samples exhibited one intense peak …

Investigation Of The Critical Current Density Of Ybacuo High-Temperature Superconductor Ceramic, Ioseb R. Metskhvarishvili, Nodar P. Kekelidze, Magda R. Metskhvarishvili

Turkish Journal of Physics

The method of high harmonics is used to investigate penetration of low magnetic fields within the Y_{1}Ba_{2}Cu_{3}O_{7} high-temperature superconductor ceramic. Given experimental results are explained by the modal dependencies between the value of critical current density and the magnetic induction B: j_{c}(B) = j_{c}(0){\frac{{B_{0}^{2}}} {{B_{0}^{2} + B^{2}}}}.

Dispersion Analysis Of Sns And Snse, Haluk Şafak, Mustafa Merdan, Ö. Faruk Yüksel

Turkish Journal of Physics

The reflectance spectra of single crystals of SnS and SnSe were measured at normal incidence by unpolarized light. The refractive indices of speciemens were calculated by Kramers-Kronig Analysis. On the basis of the Wemple diDomenico single oscillator model, the dispersion parameters were determined. It is found that the parameters obtained by unpolarized light are, in general close to those reported for polarized cases. Morever, a close similarity were observed with E//b polarization for SnS.

Free-Carrier Absorption In Quantum Well Structures For Alloy-Disorder Scattering, Guseyn Behbudoglu Ibragimov

Turkish Journal of Physics

A free-carrier absorption theory is given for quantum wells structures in III-V semiconducting materials, for the case when the carriers a scattered by alloy-disorder. It is found that absorption coefficients due to alloy-disorder and to phonons are of the same order. Results are shown that the absorption coefficient decreases with increasing photon frequency and increases with increasing temperature. It is also shown that the absorption coefficient increases with decreasing layer thickness. We also found that absorption in quantum wells structures is enhanced by going to quantum wells of smaller thickness over its value in the bulk III-V semiconducting materials.

The Effects Of Nonstoichiometry In High - T_C Superconducting Properties Of Yba_2cu_{3 + X}O_{7 - \Delta}, Beniah Ndudim Onwuagba

Turkish Journal of Physics

Polycrystalline samples of high T_c superconductor YBa_2Cu_{3 + x}O_{7 - \delta} with 0 \leqslant x \leqslant 0.5 were grown. The effects of nonstoichiometry on the resistance slope above transition temperature T_c and X-ray diffraction patterns for these samples were investigated. In the diffraction patterns obtained, apart from some new features in the peaks, these polycrystalline samples show predominantly 123 phase.

Effects Of Predation And Environment On Quality Of Yellow Perch And Bluegill Populations In Nebraska Sandhill Lakes, Craig P. Paukert, David W. Willis, Joel A. Klammer

Nebraska Game and Parks Commission: Staff Research Publications

We investigated factors that may influence the quality (e.g., high abundance, size structure, condition, and growth) of yellow perch Perca flavescens and bluegill Lepomis macrochirus populations in Nebraska sandhill lakes. Physical (e.g., lake depth, vegetation coverage), chemical (e.g., alkalinity, conductivity), and biological (e.g., chlorophyll a, invertebrate abundance) characteristics of 30 natural lakes were determined in 1998 and 1999. Growth, condition, and size structure were not density-dependent for bluegills or yellow perch in these shallow (,4mmaximum depth) lakes. However, bluegill abundance, size structure, and condition were positively related to yellow perch abundance, size structure, and condition. Bluegill quality tended to …

Modeling A Real-Time Economics Simulation With User-Coded Agents In An Object-Oriented Database, Kevin Simons

Honors Theses

A simulation tbat models the stock market with real-time stock quotes was created. Users can translate their own theories about investing into Java code, which is then used to create an intelligent agent. The agent is inserted into the simulation, which allows the agent to gather data from the model. Based on this data, the agent uses the algorithm the user wrote to buy and sell stocks. Such as model provides a means of testing investment theories before investing.

Local Participation As A Determinant Of Success In World Bank Environmental Projects: What Is The Evidence?, Catherine Benson

Honors Theses

The current impoverished, environmentally degraded state of Africa suggests that international aid projects have proven largely unsuccessful in tackling the enormous development and environment challenges faced by Africa. Africa has historically been inundated with groups trying to implement change in the form of political, economic, and environmental agendas, beginning in the colonial period and continuing today. The abundance of advice and financial assistance poured into this region have resulted in a continent lagging behind other developing regions to an even worse extent than prior to aid projects. The environment of development in Africa is complex; nowhere else in the world …

Effect Of 6-Thioguanine And Methyl-6-Thioguanine On Stability Of Dna Duplexes, Mabaera Rodwell

Honors Theses

6-Thioguanine (65G) has been used for the past thirty years as an anti-cancer agent in maintenance chemotherapy for childhood acute lymphoblastic leukemia as well as acute myeloid leukemia. Despite its long-standing clinical use, little is understood of the molecular basis of the cytotoxicity associated with ?sG. Research has shown that ?sG is incorporated into DNA during replication after which it may exert its cytotoxicity by inducing rapid mutation or by affecting DNA-protein interactions. 65G has also been shown to impair HIV replication by inhibiting HlV-l reverse transcriptase and to inhibit human telomerase activity. To further understand the structural changes associated …

Photochemical Generation And Chemistry Of Α-Acetoxycarbene, Jonathan Mann

Honors Theses

Efforts have been made at generating the parent α-acetoxycarbene from a non-nitrogenous precursor. Baeyer-Villiger oxidation of the ketone, 1-(1a,9b-dihydro-lHcyclopropa[1] phenanthren-1-yl)-ethanone, available in two steps from phenanthrene, led to the ester, 1-(1 a,9b-dihydro-lH-cyclopropa[/]phenanthren-l-yl)-acetate, which is a photochemical precursor of the parent α-acetoxycarbene intermediate. Photolysis of the ester in cyclohexene afforded an isomeric mixture of endo and exo acetates resulting from the carbene adding to the α-bond. Photolysis of the ester in trans-3-hexene yielded a single trans-cis acetate, a product of the same cycloaddition process. The formation of methyl glyoxal, via the l,2-acyl shift of the carbene, is observed through its derivatives. …

Nutrient Reserves Of Lesser Scaup During Spring Migration In The Mississippi Flyway: A Test Of The Spring Condition Hypothesis, Michael J. Anteau

LSU Master's Theses

The continental scaup population (lesser [Aythya affinis] and greater scaup [A. marila] combined) has declined markedly during the past 20 years, and has remained below the population goal of the North American Waterfowl Management Plan since 1985. One hypothesis explaining the scaup population decline states that reproductive success has decreased because females presently are arriving on breeding areas in poorer condition than that historically (Spring Condition Hypothesis [SCH]). I tested the SCH by comparing fresh body masses (FBMs) and nutrient reserves (lipid, protein, and mineral) of lesser scaup at 4 locations (Louisiana, Illinois, Minnesota, and Manitoba) in the Mississippi Flyway …

Authentic Field Ecology Experiences For Teachers, Marion Dresner, Andrew Moldenke

Environmental Science and Management Faculty Publications and Presentations

This paper will focus on one teacher field research experience situated in the Pacific Northwest

Reconnaissance Of Pharmaceutical Chemicals In Urban Streams Of The Tualatin River Basin, Oregon, 2002, Stewart A. Rounds, Micelis C. Doyle, Patrick M. Edwards, Edward T. Furlong

Environmental Science and Management Faculty Publications and Presentations

A reconnaissance of pharmaceutical chemicals in urban streams of the Tualatin River basin was conducted in July 2002 in an effort to better understand the occurrence and distribution of such compounds, and to determine whether they might be useful indicators of human-related stream contamination. Of the 21 pharmaceutical chemicals and metabolites tested, only 6 (acetaminophen, caffeine, carbamazepine, codeine, cotinine, and sulfamethoxazole) were detected in filtered stream samples from 10 sites. The concentrations of most of the detected compounds were relatively low (less than 0.05 microgram per liter). The most frequently detected compounds were cotinine (a nicotine metabolite, 8 of 10 …

Steric Hindrance As A Mechanistic Probe For Olefin Reactivity:  Variability Of The Hydrogenic Canopy Over The Isomeric Adamantylideneadamantane/Sesquihomoadamantene Pair (A Combined Experimental And Theoretical Study), Rajendra Rathore, Sergey V. Lindeman, C.-J. Zhu, T. Mori, R. Schleyer, Jay K. Kochi

Chemistry Faculty Research and Publications

Access to each CC face of adamantylideneadamantane (AA) and sesquihomoadamantene (SA) is hindered by the hydrogenic canopy consisting of four β-hydrogens; otherwise, these olefins have quite normal environments. X-ray crystallography and density functional (DFT) calculations show a 0.5 Å larger annular opening in the protective cover of AA than that in SA. This contributes to the remarkable differences in reactivity toward various reagents, not only by limiting access to the olefin site in SA but also by inhibiting reactions which force these hydrogens closer together. Thus, AA is subject to typical olefin-addition reactions with bromine, …

Polystyrene/Graphite Nanocomposites: Effect On Thermal Stability, Fawn Marie Uhl, Charles A. Wilkie

Chemistry Faculty Research and Publications

Nanocomposites consisting of polymer and clay have been shown to exhibit a significant reduction in flammability and an increase in mechanical properties. This work examines the effect of thermal stability and mechanical properties of nanocomposites prepared from potassium graphite and styrene. Synthesis of nanocomposites was accomplished by using potassium graphite (KC₈) as the initiator in the polymerization of styrene. A slight increase in thermal stability is observed but mechanical properties are decreased.

Direct Sequential Simulation Algorithms In Geostatistics, Robyn Robertson

Theses : Honours

Conditional sequential simulation algorithms have been used in geostatistics for many years but we currently find new developments are being made in this field. This thesis presents two new direct sequential simulation with histogram reproduction algorithms and compares them with the efficient and widely used sequential Gaussian simulation algorithm and the original direct sequential simulation algorithm. We explore the possibility of reproducing both the semivariogram and the histogram without the need for a transformation to normal space, through optimising an objective function and placing linear constraints on the local conditional distributions. Programs from the GSLIB Fortran library are expanded to …

Tests 2023 & 2024: Case Ih Jx 95 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Test 2097: Mccormick Mtx 110 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Nebraska Summary 384: John Deere 6120 Syncroplus Diesel 12-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA

The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data.

EXPLANATION OF THE TEST PROCEDURES

Purpose

The purpose of …

Test 1808: John Deere 6403 Diesel 9-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA

The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data.

EXPLANATION OF THE TEST PROCEDURES

Purpose

The purpose of …

Nebraska Summary 386: John Deere 6320 Powrquad Plus 16-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA

The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data.

EXPLANATION OF THE TEST PROCEDURES

Purpose

The purpose of …

Nebraska Summary: S422 Mccormick Mtx 125, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Nebraska Summary 382: Agco Rt115 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Test 1803: John Deere 9320 18 Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Tests 2031 & 2055: Case Ih Jx 85 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Nebraska Summary: S276 Massey Ferguson 4225, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Nebraska Summary: S322 Massey Ferguson 4360, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Nebraska Summary: S406 Case-Ih Jx95, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …