Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 70351 - 70380 of 78841

Full-Text Articles in Entire DC Network

Analysis Of Images Of Cells With Neurites, Florence Cloppet, Georges Stamon Jan 1998

Analysis Of Images Of Cells With Neurites, Florence Cloppet, Georges Stamon

Turkish Journal of Electrical Engineering and Computer Sciences

This study is concerned with the segmentation of cytological images and extraction of cellular entities in order to provide quantitative data about the number of cells in culture (statistical tests, morphology, model of evolution, etc). This quantitative supply is useful in biology to evaluate the consequences of the application of active substances on morphological changes and cellular viability. It is related to the conception of a system dedicated to automatic analysis of cell images, in order to evaluate the effects of drugs on the morphology of neuronal cells. We use a cooperative region / contour segmentation, which gives closed polygonal …


Imaging Electrical Current Density Using Nuclear Magnetic Resonance, B. Murat Eyüpoğlu, Ravinder Reddy, John S. Leigh Jan 1998

Imaging Electrical Current Density Using Nuclear Magnetic Resonance, B. Murat Eyüpoğlu, Ravinder Reddy, John S. Leigh

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, images of nonuniform and uniform electric current density in conductor phantoms, which contain magnetic resonance active nuclei, are produced using Magnetic Resonance Imaging (MRI). A standard spin echo pulse sequence is used, with the addition of a bipolar current pulse. The flux density parallel to the main magnetic field, generated by the current pulse, is encoded in the phase of the complex MR image. The spatial distribution of magnetic flux density is extracted from the phase image. Current density is calculated using the magnetic flux density. This fairly recent technique is known as Magnetic Resonance Current Density …


Use Of The Magnetic Field Generated By The Internal Distribution Of Injected Currents For Electrical Impedance Tomography (Mr-Eit), Y. Zi̇ya İder, Özlem Bi̇rgül Jan 1998

Use Of The Magnetic Field Generated By The Internal Distribution Of Injected Currents For Electrical Impedance Tomography (Mr-Eit), Y. Zi̇ya İder, Özlem Bi̇rgül

Turkish Journal of Electrical Engineering and Computer Sciences

In two dimensional conventional Electrical Impedance Tomography (EIT), volume conductor is probed by means of injected currents, and peripheral voltage measurements are used as input to the reconstruction algorithm. The current that flows in the 2D object creates magnetic fields that are perpendicular to the plane of imaging. Such magnetic fields can be measured using magnetic resonance tomography. In this study, use of this magnetic field generated by the injected currents, for the purpose of reconstructing the conductivity distribution, is studied. Sensitivity matrix relating the magnetic field to the element conductivities is calculated using the Finite Element Method and Biot-Savart …


Fdtd Evaluation Of The Sar Distribution In A Human Head Near A Mobile Cellular Phone, Selçuk Paker, Levent Sevgi̇ Jan 1998

Fdtd Evaluation Of The Sar Distribution In A Human Head Near A Mobile Cellular Phone, Selçuk Paker, Levent Sevgi̇

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, Finite-Difference Time-Domain (FDTD) method is used to calculate the Specific Absorbtion Rate (SAR; defined as the power absorbed by unit mass of the tissue) distribution in a human head near a hand-held cellular phone. A three dimensional FDTD algorithm is built in cartesian coordinates. A discrete human head model, derived from a Nuclear Magnetic Resonance (NMR) image by semi-automatic algorithm, is located within FDTD volume together with a discrete hand-held receiver model. FDTD simulations are carried out for both european GSM (operating at 900MHz) and DECT (operating at 1.8GHz) systems with a quarter-wavelength antenna, mounted on top …


Ecological Resilience, Biodiversity, And Scale, Garry D. Peterson, Craig R. Allen, C. S. Holling Jan 1998

Ecological Resilience, Biodiversity, And Scale, Garry D. Peterson, Craig R. Allen, C. S. Holling

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

We describe existing models of the relationship between species diversity and ecological function, and propose a conceptual model that relates species richness, ecological resilience, and scale.We suggest that species interact with scale-dependent sets of ecological structures and processes that determine functional opportunities. We propose that ecological resilience is generated by diverse, but overlapping, function within a scale and by apparently redundant species that operate at different scales, thereby reinforcing function across scales. The distribution of functional diversity within and across scales enables regeneration and renewal to occur following ecological disruption over a wide range of scales.


Larval Black Crappie Distribution: Implications For Sampling Impoundments And Natural Lakes, Kevin L. Pope, David W. Willis Jan 1998

Larval Black Crappie Distribution: Implications For Sampling Impoundments And Natural Lakes, Kevin L. Pope, David W. Willis

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

An understanding of larval fish distributions is essential for developing an appropriate sampling design to monitor larval abundances. We monitored abundance of larval black crappie Pomoxis nigromaculatus to assess spatial differences in Richmond Lake (a 336-ha impoundment) and Brant Lake (a 405-ha natural lake), South Dakota, during 1994–1996. Age-0 black crappies were collected with a 500-µm mesh ichthyoplankton trawl from fixed sites within each water body. In the impoundment, larval black crappies were collected over a longer period at the upper site than at the dam site during 1994 and 1995. In the natural lake, larval black crappie abundances were …


1997 Inventory For Spiranthes Diluvialis Sheviak In Western Nebraska: A Final Report, Volume Ii, Terri Hildebrand Jan 1998

1997 Inventory For Spiranthes Diluvialis Sheviak In Western Nebraska: A Final Report, Volume Ii, Terri Hildebrand

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

This study resulted from an agreement between Nebraska Game and Parks Commission (NGPC) and the United States Fish and Wildlife Service (USFW). After the 1996 discovery of Spiranthes diluvialis, in western Nebraska, NGPC was seeking to determine the extent of the Nebraska population. Information on the wet meadow community of orchid occurrence in Nebraska and eastern Wyoming was needed. This report includes descriptions of communities inventoried, Spiranthes diluvialis populations, and additional species monitored by Nebraska and Wyoming Natural Heritage programs.

Between May and September 1997, potential Spiranthes diluvialis habitat was inventoried for occurrences of the orchid. For all sites …


Declines In Benthic Macroinvertebrate Populations In Southern Lake Michigan, 1980–1993, Thomas F. Nalepa, David J. Hartson, David L. Fanslow, Gregory A. Lang, Stephen J. Lozano Jan 1998

Declines In Benthic Macroinvertebrate Populations In Southern Lake Michigan, 1980–1993, Thomas F. Nalepa, David J. Hartson, David L. Fanslow, Gregory A. Lang, Stephen J. Lozano

United States Department of Commerce: Staff Publications

Densities of the major benthic macroinvertebrate groups declined dramatically at sites shallower than 50 m in southern Lake Michigan between 1980 and 1993. Declines in Diporeia, Oligochaeta, and Sphaeriidae ranged from 40 to 75% at these depths. Total densities declined from 16 800·m–2 in 1980–1981 to 4,800·m–2 in 1992–1993 at sites in the 16–30 m depth interval and from 21,300 to 11,300·m–2 at sites in the 31–50 m depth interval. Changes at sites deeper than 50 m were minimal; only sphaeriids declined to any extent. Declines in oligochaetes and sphaeriids occurred uniformly throughout the nearshore region …


1998 Platte River Basin Ecosystem Symposium Proceedings Jan 1998

1998 Platte River Basin Ecosystem Symposium Proceedings

Water Current Newsletter

No abstract provided.


Status Of Aphis Vertebrate Pesticides And Drugs, Kathleen A. Fagerstone, Edward W. Schafer Jr. Jan 1998

Status Of Aphis Vertebrate Pesticides And Drugs, Kathleen A. Fagerstone, Edward W. Schafer Jr.

Vertebrate Pest Conference Proceedings: 18th (1998)

The Wildlife Services (WS) Program manages wildlife/human conflicts by using an integrated approach employing some vertebrate pesticides. These are used in such small quantities that private industry cannot afford to register and produce them profitably. On behalf of WS, the Animal and Plant Health Inspection Service (APHIS) maintains about 30 federal and state pesticide registrations, containing seven active ingredients, with the U.S. Environmental Protection Agency (EPA). These include: the Compound 1080 Livestock Protection Collar, DRC-1339 Concentrates (Starlicide), Gas Cartridges (carbon and sodium nitrate), the M-44 (sodium cyanide), and a number of baits and concentrates containing Strychnine Alkaloid and Zinc Phosphide. …


Tsw Wildlife Damage Management Working Group Newsletter:Spring 1998 - Volume 5(2) - Election Issue Jan 1998

Tsw Wildlife Damage Management Working Group Newsletter:Spring 1998 - Volume 5(2) - Election Issue

TWS Wildlife Damage Management Working Group Newsletter

Forward -- Scott Hygnstrom Postdoctoral Position With The Jack Berryman Institute; 1998 Winners Of The Jack H. Berryman Institute Awards; Preliminary Program For The Wildlife Society 5th Annual Conference, September 22-26, 1998, Buffalo, Ny; Candidates For The Working Group Executive Board Future Newsletter; Contributions; From Around The World!; Wildlife Damage Management Working Group Ballot - May 1998 ; Plenary Abstracts From The 18th Vertebrate Pest Conference, 2-5 March 1998, Costa Mesa, Ca; Available Publications; Future Events Of Interest; Next Edition Deadline; Application For Membership / The Wildlife Society; Contributors To This Issue


Tws Wildlife Damage Management Working Group Newsletter: Fall 1998 - Volume 5(4) Jan 1998

Tws Wildlife Damage Management Working Group Newsletter: Fall 1998 - Volume 5(4)

TWS Wildlife Damage Management Working Group Newsletter

Forward -- Scott Craven; The Wildlife Society Wildlife Damage Management Working Group 1998 Annual Meeting September 23, 1998, 6-8 Pm, Buffalo, Ny; Next Edition Deadlines; The Wildlife Society Wildlife Damage Management Working Group 1998 Report To Council; Candidates For The Working Group Officers - December 1998 ; 1998-99 Wildlife Damage Management Working Group Officers; Wildlife Damage Management Working Group Ballot - December 1998; Wildlife Damage Management Around The World - Part 2; Sika Deer Management In Nikko National Park, Japan; Current Status And Future Direction; Contributors To This Issue ; Application For Membership / The Wildlife Society


A Mathematical Model For Fibroblast And Collagen Orientation, J. C. Dallon, J. A. Sherratt Jan 1998

A Mathematical Model For Fibroblast And Collagen Orientation, J. C. Dallon, J. A. Sherratt

Faculty Publications

Due to the increasing importance of the extracellular matrix in many biological problems, in this paper we develop a model for fibroblast and collagen orientation with the ultimate objective of understanding how fibroblasts form and remodel the extracellular matrix, in particular its collagen component. The model uses integro-differential equations to describe the interaction between the cells and fibers at a point in space with various orientations. The equations are studied both analytically and numerically to discover different types of solutions and their behavior. In particular we examine solutions where all the fibroblasts and collagen have discrete orientations, a localized continuum …


Heme Transfer Reactions: An Important Prerequisite For Synthetic Oxygen Carriers, Jan Paul, Wenhua Chen, Per-Ingvar Ohlsson, Michael Smith Jan 1998

Heme Transfer Reactions: An Important Prerequisite For Synthetic Oxygen Carriers, Jan Paul, Wenhua Chen, Per-Ingvar Ohlsson, Michael Smith

Turkish Journal of Chemistry

Electronic changes of iron- and metal free porphyrins are reviewed in light of their importance to modify the ferri/ferro reduction potential and energy dissipation between ligated carbon monoxide and the porphyrin chelate. Substitutions at positions 2 and 4 are effective ways to exercise this influence. Other measures include exposure to water and modifications of axial ligation, including the \lq three-ligand' case. These measures will also influence the stability of recombined hemin-protein entities, as apparent from the kinetics of heme-transfer from a modified donor protein to apomyoglobin, but the stability appears to be related to the bulkiness of 2,4-substitutional groups rather …


Determination Of The Protonation Constants Of 2-[4-Dimethylaminocinnamalamino] Benzoic Acid (Dacab) In Dioxane - Water Medium And Preparation Of Some Of Its Transition Metal Complexes, Mustafa Yalçin, Harun Mutluay, Hüsnü Cankurtaran Jan 1998

Determination Of The Protonation Constants Of 2-[4-Dimethylaminocinnamalamino] Benzoic Acid (Dacab) In Dioxane - Water Medium And Preparation Of Some Of Its Transition Metal Complexes, Mustafa Yalçin, Harun Mutluay, Hüsnü Cankurtaran

Turkish Journal of Chemistry

In this study, the Schiff base 2-[4-Dimethylaminocinnamalamino]- benzoic acid [(CH$_3$)$_2$N.C$_6$H$_4$.CH:CH.N.C$_6$H$_4$.COOH] (DACAB) was prepared by the reaction of 2-Aminobenzoic acid with p-Dimethylaminocinnamaldehyde. The protonation constants of the ligand were determined in a 50\% (v/v) dioxane - water medium using the Irving-Rossotti and PKAS-BEST computer methods. The complexes of Fe(III), Co(II), Ni(II), Cu(II) with DACAB were synthesized and the structures of these complexes were elucidated by means of data obtained from elemental analysis, using IR, $^1$H-NMR methods. The magnetic properties of the solid complexes were measured.


Reactions Of 4-Amino-4,5-Dihydro-1h-1,2,4-Triazol-5-Ones And 4-Amino-4h-1,2,4-Triazoles With Some Carboxylic Acid Anhydrides, Şule Bahçeci̇, Nurhan İnce, Asun İki̇zler Jan 1998

Reactions Of 4-Amino-4,5-Dihydro-1h-1,2,4-Triazol-5-Ones And 4-Amino-4h-1,2,4-Triazoles With Some Carboxylic Acid Anhydrides, Şule Bahçeci̇, Nurhan İnce, Asun İki̇zler

Turkish Journal of Chemistry

3-Alkyl(Aryl)-4-tetrachlorophthalimido-4,5-dihydro-1H-1,2,4-triazol-5-ones (2) and 3-alkyl(aryl)-4-(1,8-naphthalimido)-4,5-dihydro-1H-1,2,4-triazol-5-ones (3) were synthesized from the reactions of 3-alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (1) with tetrachlorophthalic anhydride and 1,8-naphthalic anhydride, respectively. In addition, the reactions of 4-amino-4H-1,2,4-triazoles (4) with succinic anhydride and phthalic anhydride were studied.


Fatty Acid Composition And Cholesterol Content Of Some Turkish Fish Species, Sedat İmre, Serap Sağlik Jan 1998

Fatty Acid Composition And Cholesterol Content Of Some Turkish Fish Species, Sedat İmre, Serap Sağlik

Turkish Journal of Chemistry

It is well known that fish lipids are effective against cardiovascular diseases due to their high contents of polyunsaturated omega-3 (n-3) fatty acids. In order to determine a suitable fish diet, the fatty acid compositions and total lipid and cholesterol contents of 9 common fish species obtained from the central fish market in Ğstanbul were determined. Palmitic (C-16:0) and oleic acid (C-18:1) were the predominant saturated and monounsaturated fatty acids. The predominant polyunsaturated fatty acids were eicosapentaenoic (C-20:5) acid and docosahexaenoic (C-22:6) acid. The amounts of cholesterol in fish lipids did not differ significantly. Sardine ({\it Sardina pilchardus}) and mackerel …


Determination Of Structure-Toxicity Relationship Of Amphiprotic Compounds By Means Of The Inhibition Of The Dehydrogenase Activity Of Pseudomonas Putida, Ş. Gül, D. Öztürk Jan 1998

Determination Of Structure-Toxicity Relationship Of Amphiprotic Compounds By Means Of The Inhibition Of The Dehydrogenase Activity Of Pseudomonas Putida, Ş. Gül, D. Öztürk

Turkish Journal of Chemistry

Aliphatic and aromatic alcohols are amphiprotic compounds which have both polar and nonpolar parts in their structure. These compounds were studied with respect to the nonreactive toxic effects on the microorganism {\it Pseudomonas putida}. The toxicity of these chemicals to aerobic bacterium {\it P. putida} was measured in terms of inhibition of dehydrogenase activity. The test results, expressed as concentration of chemicals 50\% effective in inhibition (IC$_{50}$), were correlated with their physicochemical properties such as aqueous solubility (S) and octanol-water partition coefficient (P).


Comparison Of Different Production Processes For Bioethanol, B. Çaylak, Fazilet Vardar Sukan Jan 1998

Comparison Of Different Production Processes For Bioethanol, B. Çaylak, Fazilet Vardar Sukan

Turkish Journal of Chemistry

In this study, ethanol was produced with the microorganism {\em Saccharomyces cerevisiae} by using sucrose as a substrate. Batch processes were tested by using the same substrate, microorganism and medium composition. {\em Saccharomyces cerevisiae}, used in the free form in the first group of experiments, was immobilized by different methods. In the second group of experiments agar, sponge and a natural material called luffa cylindrica fiber were used as support materials. The batch processes with free and immobilized microorganisms were compared with respect to efficiency and yield.


Winchell Posters Jan 1998

Winchell Posters

Journal of the Minnesota Academy of Science

Abstracts from the Winchell Posters given at the 66th Annual Meeting for the Journal of the Minnesota Academy of Science.


Steady State Memetic Algorithm For Partial Shape Matching, Ender Ozcan, Chilukuri K. Mohan Jan 1998

Steady State Memetic Algorithm For Partial Shape Matching, Ender Ozcan, Chilukuri K. Mohan

Electrical Engineering and Computer Science - All Scholarship

Shape matching techniques are important in machine intelligence, especially in applications such as robotics. Currently, there are three major approaches to shape recognition: statistical, syntactic and neural approaches. This paper presents a fourth approach: evolutionary algorithms. A steady state memetic algorithm is shown to be successful in matching shapes even when they are partially obscured, and even in the presence of noise in the input image.


University Of Texas At Tyler Freshman Catalog, 1998-1999, University Of Texas At Tyler Jan 1998

University Of Texas At Tyler Freshman Catalog, 1998-1999, University Of Texas At Tyler

Catalogs

Archives Space instance: https://archivesspace.uttyler.edu/repositories/2/archival_objects/22363


Test 1703s - S191: New Holland 4630 (Chassis S/N *0911518* And Higher), Nebraska Tractor Test Lab Jan 1998

Test 1703s - S191: New Holland 4630 (Chassis S/N *0911518* And Higher), 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: S328 Case-Ih C90, Nebraska Tractor Test Lab Jan 1998

Nebraska Summary: S328 Case-Ih C90, 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: S501 Kubota M6800dt, Nebraska Tractor Test Lab Jan 1998

Nebraska Summary: S501 Kubota M6800dt, 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 276: Massey Ferguson 4325 And 4225 Diesel 12-Speed, Nebraska Tractor Test Lab Jan 1998

Nebraska Summary 276: Massey Ferguson 4325 And 4225 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 …


Nebraska Summary 278: Massey Ferguson 4345, 4245 And 4243 Diesel 12-Speed, Nebraska Tractor Test Lab Jan 1998

Nebraska Summary 278: Massey Ferguson 4345, 4245 And 4243 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 …


Nebraska Summary 286: John Deere 6110 Powrquad Diesel 16-Speed, Nebraska Tractor Test Lab Jan 1998

Nebraska Summary 286: John Deere 6110 Powrquad Diesel 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 279: Massey Ferguson 4253, 4255 And 4355 Diesel 12-Speed, Nebraska Tractor Test Lab Jan 1998

Nebraska Summary 279: Massey Ferguson 4253, 4255 And 4355 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 …


Nebraska Summary 289: John Deere 6310 Powrquad Diesel 16-Speed, Nebraska Tractor Test Lab Jan 1998

Nebraska Summary 289: John Deere 6310 Powrquad Diesel 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 …