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1999

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Articles 1861 - 1890 of 2555

Full-Text Articles in Physical Sciences and Mathematics

From Reclamation To Sustainability: Water, Agriculture, And The Environment In The American West, Lawrence J. Macdonnell Jan 1999

From Reclamation To Sustainability: Water, Agriculture, And The Environment In The American West, Lawrence J. Macdonnell

Books, Reports, and Studies

This digital resource contains only an abstract, cover image and table of contents information from the published book.

Print copy of book is available in the University of Colorado’s Wise Law Library: http://lawpac.colorado.edu/record=b236740~S0

Contents: Introduction : Living in a land of limited water -- PART 1. THE LOWER ARKANSAS VALLEY : AFTER THE WATER IS GONE: Colorado's Arkansas River -- Watering and cultivating the prairie -- Stretching a limited water supply -- Irrigation water for sale? -- A hostile takeover? -- Looking ahead -- PART 2. THE GRAND VALLEY, COLORADO : WHERE FRUIT, FISH, AND GROWTH COLLIDE: Growing peaches in …


A Feature Library Approach To On-Line Image Querying And Retrieval For Topographic Applications, James Carswell Jan 1999

A Feature Library Approach To On-Line Image Querying And Retrieval For Topographic Applications, James Carswell

Conference papers

In this paper we address the problem of content-based image retrieval using queries on shape and topology. We focus on the particularities of image databases encountered in typical topographic applications, and present the development of a spatial data management system that enables such queries. The query uses as input user-provided sketches of the shape and spatial configuration of the object (or objects) which should appear in the images to be retrieved. The objective of the search is to retrieve images that contain a configuration of objects sufficiently similar to the one specified in the query. Our novel approach introduces the …


The Gateway System: Uniform Web Based Access To Remote Resources, Geoffrey C. Fox, Tomasz Haupt, Erol Akarsu, Alexey Kalinichenko, Kang-Seok Kim Jan 1999

The Gateway System: Uniform Web Based Access To Remote Resources, Geoffrey C. Fox, Tomasz Haupt, Erol Akarsu, Alexey Kalinichenko, Kang-Seok Kim

Northeast Parallel Architecture Center

Exploiting our experience developing the WebFlow system, we designed the Gateway system to provide seamless and secure access to computational resources at ASC MSRC. The Gateway follows our commodity components strategy, and it is implemented as a modern three-tier system. Tier 1 is a high-level front end for visual programming, steering, run-time data analysis and visualization that is built on top of the Web and OO commodity standards. Distributed object-based, scalable, and reusable Web server and Object broker middleware forms Tier 2. Back-end services comprise Tier 3. In particular, access to high-performance computational resources is provided by implementing the emerging …


Using Webhla To Integrate Hpc Fms Modules With Web/Commodity Based Distributed Object Technologies Of Corba, Java, Com And Xml, Geoffrey C. Fox, Wojtek Furmanski, Ganesh Krishnamurthy, Hasan T. Ozdemir, Zeynep Odcikin-Ozdemir, Tom A. Pulikal, Krishnan Rangarajan, Ankur Sood Jan 1999

Using Webhla To Integrate Hpc Fms Modules With Web/Commodity Based Distributed Object Technologies Of Corba, Java, Com And Xml, Geoffrey C. Fox, Wojtek Furmanski, Ganesh Krishnamurthy, Hasan T. Ozdemir, Zeynep Odcikin-Ozdemir, Tom A. Pulikal, Krishnan Rangarajan, Ankur Sood

Northeast Parallel Architecture Center

HLA standards for interoperability between various DoD Modeling and Simulation paradigms are being enforced in parallel with the rapid onset of new Object Web / Commodity standards for distributed objects and componentware, emergent at the crossroads of CORBA, COM, Java, and XML technologies. WebHLA explores synergies between and integrates both trends by offering Object Web based implementation of the HLA framework. Our goal is to deliver a uniform platform that facilitates conversion of legacy codes to and development of new codes in compliance with HLA, HPC and Object Web standards. We outline here the overall design of WebHLA, we summarize …


Mpijava 1.2: Api Specification, Bryan Carpenter, Geoffrey C. Fox, Sung-Hoon Ko, Sang Lim Jan 1999

Mpijava 1.2: Api Specification, Bryan Carpenter, Geoffrey C. Fox, Sung-Hoon Ko, Sang Lim

Northeast Parallel Architecture Center

This document defines the API of mpiJava, a Java language binding for MPI 1.1. The document is not a standalone specification of the behaviour of MPI--it is meant to be read in conjunction with the MPI standard document [2]. Subsections are laid out in the same way as in the standard document, to allow cross-referencing. Where the mpiJava binding makes no significant change to a particular section of the standard document, we will just note here that there are no special issues for the Java binding. This does not mean that the corresponding section of the standard is irrelevant to …


Thoughts On The Structure Of An Mpj Reference Implementation, Mark Baker, Bryan Carpenter Jan 1999

Thoughts On The Structure Of An Mpj Reference Implementation, Mark Baker, Bryan Carpenter

Northeast Parallel Architecture Center

We sketch a proposed reference implementation for MPJ, the Java Grande Forum's MPI-like message-passing API [9, 3]. The proposal relies heavily on RMI and Jini for finding computational resources, creating slave processes, and handling failures. User-level communication is implemented efficiently directly on top of Java sockets.


Internetics: Technologies, Applications And Academic Field, Or, Parallel Computing And Computational Science Do Not Quite Work, Geoffrey C. Fox Jan 1999

Internetics: Technologies, Applications And Academic Field, Or, Parallel Computing And Computational Science Do Not Quite Work, Geoffrey C. Fox

Northeast Parallel Architecture Center

Ten years ago, we were all sure that parallel computing technology and the interdisciplinary academic field of computational science would be center pieces of both academic and economic growth. We show that this insight was, in principle, correct but was an incomplete vision for large-scale computation implies both increased computer power and increasing numbers of users and applications. Parallel computing undoubtedly works on essentially all problems, but we were unable to produce deployable software systems. Further, few industries could achieve adequate return to justify investment in parallel computers, except in a few areas such as databases. Computational science is the …


Building Distributed Systems For The Pragmatic Object Web, Geoffrey C. Fox, Wojtek Furmanski, Tomasz Haupt Jan 1999

Building Distributed Systems For The Pragmatic Object Web, Geoffrey C. Fox, Wojtek Furmanski, Tomasz Haupt

Northeast Parallel Architecture Center

We review the growing power and capability of commodity computing and communication technologies largely driven by commercial distributed information systems. These systems are built from CORBA, Microsoft's COM, JavaBeans, and rapidly advancing Web approaches. One can abstract these to a three-tier model with largely independent clients connected to a distributed network of servers. The latter host various services including object and relational databases and of course parallel and sequential computing. High performance can be obtained by combining concurrency at the middle server tier with optimized parallel back end services. The resultant system combines the needed performance for large-scale HPCC applications …


Mpijava: An Object-Oriented Java Interface To Mpi, Mark Baker, Bryan Carpenter, Geoffrey C. Fox, Sung Hoon Ko Jan 1999

Mpijava: An Object-Oriented Java Interface To Mpi, Mark Baker, Bryan Carpenter, Geoffrey C. Fox, Sung Hoon Ko

Northeast Parallel Architecture Center

A basic prerequisite for parallel programming is a good communication API. The recent interest in using Java for scientific and engineering application has led to several international efforts to produce a message passing interface to support parallel computation. In this paper we describe and then discuss the syntax, functionality and performance of one such interface, mpiJava, an object-oriented Java interface to MPI. We first discuss the design of the mpiJava API and the issues associated with its development. We then move on to briefly outline the steps necessary to 'port' mpiJava onto a range of operating systems, including Windows NT, …


International R&D Spillovers: An Application Of Estimation And Inference In Panel Cointegration, Chihwa Kao, Min-Hsien Chiang, Bangtian Chen Jan 1999

International R&D Spillovers: An Application Of Estimation And Inference In Panel Cointegration, Chihwa Kao, Min-Hsien Chiang, Bangtian Chen

Center for Policy Research

In this paper, we apply the asymptotic theory of panel cointegration developed by Kao and Chiang (1997) to Coe and Helpman's (1995) international R&D spillovers regression. The OLS with bias-correction, the fully-modified (FM) and the dynamic OLS (DOLS) estimations produce different predictions about the impact of foreign R&D on total factor productivity (TFP), although all the estimations support the result that domestic R&D is related to TFP.


On The Estimation And Inference Of A Cointegrated Regression In Panel Data, Chihwa Kao Jan 1999

On The Estimation And Inference Of A Cointegrated Regression In Panel Data, Chihwa Kao

Center for Policy Research

The main contribution of this paper is to add to the literature by suggesting a dynamic OLS (DOLS) estimator and providing a serious comparison of the finite sample properties of the OLS, fully modified OLS (FMOLS), and DOLS estimators in panel cointegrated regression models. Monte Carlo results illustrate the sampling behavior of the proposed estimators and show that (1) the OLS estimator has a non-negligible bias in finite samples, (2) the FMOLS estimator does not improve over the OLS estimator in general, and (3) the DOLS outperforms both the OLS and FMOLS estimators.


A Monte Carlo Comparison Of Tests For Cointegration In Panel Data, Chihwa Kao Jan 1999

A Monte Carlo Comparison Of Tests For Cointegration In Panel Data, Chihwa Kao

Center for Policy Research

This paper surveys recent developments and provides Monte Carlo comparison on various tests proposed for cointegration in panel data. In particular, tests for two panel models, varying intercepts and varying slopes, and varying intercepts and common slopes are presented from the literature with a total of seven tests being simulated. In all cases, results on empirical size and size-adjusted power are given.


On The Estimation Of A Linear Time Trend Regression With A One-Way Error Component Model In The Presence Of Serially Correlated Errors, Chihwa Kao, Jamie Emerson Jan 1999

On The Estimation Of A Linear Time Trend Regression With A One-Way Error Component Model In The Presence Of Serially Correlated Errors, Chihwa Kao, Jamie Emerson

Center for Policy Research

In this paper we study the limiting distributions for ordinary least squares (OLS), fixed effects (FE), first difference (FD), and generalized least squares (GLS) estimators in a linear time trend regression with a one-way error component model in the presence of serially correlated errors. We show that when the error term is I(0), the FE is asymptotically equivalent to the GLS. However, when the error term is I(1) the GLS could be less efficient than the FD or FE estimators, and the FD is the most efficient estimator. However, when the intercept is included in the model and the error …


Habitat Fragmentation In Transplanted Eelgrass (Zostera Marina) Beds: Effects On Decapods And Fish, Alfonso Vollmer Lombana Jan 1999

Habitat Fragmentation In Transplanted Eelgrass (Zostera Marina) Beds: Effects On Decapods And Fish, Alfonso Vollmer Lombana

Dissertations, Theses, and Masters Projects

No abstract provided.


Geology Of Rock Creek Station State Historical Park, Robert F. Diffendal Jr. Jan 1999

Geology Of Rock Creek Station State Historical Park, Robert F. Diffendal Jr.

School of Natural Resources: Faculty Publications

Contents

Location and Facilities
Geology of the Park
Valley Floor of Rock Creek
While You Are in the Area


Geology And Ground Water, Garden County, Nebraska, Robert F. Diffendal Jr. Jan 1999

Geology And Ground Water, Garden County, Nebraska, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

All of Garden County (Nebraska) is underlain by the Brule Formation. This formation is tightly cemented and yields sufficient water to wells only in areas where the siltstone has been fractured. In most places the Brule Formation forms an impermeable seal that prevents water from moving downward from the overlying aquifers. The Arikaree Group is unimportant as an aquifer in the county, but the younger Ash Hollow Formation is important, particularly beneath the Cheyenne Tableland. Most, if not all, of the domestic and livestock wells on the tableland tap this aquifer. The thickness of the Ash Hollow Formation is 100 …


A Synthesis For Testability Scheme For Finite State Machines Using Clock Control, Kent L. Einspahr, Shashank K. Mehta, Sharad C. Seth Jan 1999

A Synthesis For Testability Scheme For Finite State Machines Using Clock Control, Kent L. Einspahr, Shashank K. Mehta, Sharad C. Seth

School of Computing: Faculty Publications

A new method is proposed for improving the testability of a finite state machine (FSM) during its synthesis. The method exploits clock control to enhance the controllability and observability of machine states. With clock control it is possible to add new state transitions during testing. Therefore, it is easier to navigate between states in the resulting test machine. Unlike prior work, where clock control is added to the circuit as a postdesign step, here, clock control is considered in conjunction with a symbolic scheme for encoding the states of the FSM. The encoding is shown to result in significant reductions …


Lagrangian Systems On Hyperbolic Manifolds, Philip Boyland, Christophe Golé Jan 1999

Lagrangian Systems On Hyperbolic Manifolds, Philip Boyland, Christophe Golé

Mathematics Sciences: Faculty Publications

This paper gives two results that show that the dynamics of a time-periodic Lagrangian system on a hyperbolic manifold are at least as complicated as the geodesic flow of a hyperbolic metric. Given a hyperbolic geodesic in the Poincaré ball, Theorem A asserts that there are minimizers of the lift of the Lagrangian system that are a bounded distance away and have a variety of approximate speeds. Theorem B gives the existence of a collection of compact invariant sets of the Euler-Lagrange flow that are semiconjugate to the geodesic flow of a hyperbolic metric. These results can be viewed as …


Measurement Of The Diffractive Cross Section In Deep Inelastic Scattering Using Zeus 1994 Data, J. Breitweg, M. Derrick, D. Krakauer, S. Magill, D. Mikunas, B. Musgrave, J. Repond, R. Stanek, R. L. Talaga, R. Yoshida, H. Zhang, Margarita C. K. Mattingly, F. Anselmo, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, G. Castellini, L. Cifarelli, F. Cindolo, A. Contin, N. Coppola, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, G. Laurenti Jan 1999

Measurement Of The Diffractive Cross Section In Deep Inelastic Scattering Using Zeus 1994 Data, J. Breitweg, M. Derrick, D. Krakauer, S. Magill, D. Mikunas, B. Musgrave, J. Repond, R. Stanek, R. L. Talaga, R. Yoshida, H. Zhang, Margarita C. K. Mattingly, F. Anselmo, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, G. Castellini, L. Cifarelli, F. Cindolo, A. Contin, N. Coppola, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, G. Laurenti

Faculty Publications

The DIS diffractive cross section, dσdiffγ*p→XN/dMx, has been measured in the mass range Mx < 15 GeV for γ*p c.m. energies 60 < W < 200 GeV and photon virtualities Q2 = 7 to 140 GeV2. For fixed Q2 and Mx, the diffractive cross section rises rapidly with W, dσdiffγ*p→X N (Mx, W, Q2)/dMx ∝ Wadiff with adiff = 0.507 ± 0.034 (stat) +0.155-0.046 (syst) corresponding to a t-averaged pomeron trajectory of ̄αℙ = 1.127 ± 0.009 (stat) +0.039-0.012 (syst) which is larger than ̄αℙ observed in hadron-hadron scattering. The W dependence of the diffractive cross section is found to be the same as that of the total cross section for scattering of virtual photons on protons. The data are consistent with the assumption that the diffractive structure function FD(3)2 factorizes according to cursive greek chiℙFD(3)2(cursive greek chiℙ, β, Q2) = (cursive greek chi0//cursive greek chiℙ)nFD(2)2(β, Q2). They are also consistent with QCD based models which incorporate factorization breaking. The rise of cursive greek chiℙFD(3)2 with decreasing cursive greek chiℙ and the weak dependence of FD(2)2 on Q2 suggest a substantial contribution from partonic interactions.


The Deconstruction Of Mathematics: A Criticism Of Reuben Hersh's What Is Mathematics, Really? And The Humanist Philosophy Of Mathematics, David J. Stucki Jan 1999

The Deconstruction Of Mathematics: A Criticism Of Reuben Hersh's What Is Mathematics, Really? And The Humanist Philosophy Of Mathematics, David J. Stucki

Mathematics Faculty Scholarship

Mathematics, as an academic discipline, has stood for many years as the last bastion against a growing tide of intellectual relativism that has become all but ubiquitous. More recently, however, efforts have been made to "humanize" mathematics by advocating a social-constructivist approach to the philosophy of mathematics, both in practice and education. This paper is intended to serve as a critical response to one advocate of this approach, Reuben Hersh (What Is Mathematics, Really?, 1997), and in the process a defense of Platonism.


Utilization Of Printer Resources Within A Computer Graphics Department: A Print Queue Analysis, Prentice Frazier Jan 1999

Utilization Of Printer Resources Within A Computer Graphics Department: A Print Queue Analysis, Prentice Frazier

Theses and Dissertations

This paper examines print queue management for the graphics department of a financial services company. The current network configuration has proven to be sub-optimal. The IT department is currently undergoing testing of possible alternative network configurations. The objective is to improve performance by leveraging existing resources with new technology. In this paper, the effect of consolidating the queue into one primary queue manager is analyzed, along with prioritizing print jobs, and forecasting future printer needs. Analysis was performed using queuing theory concepts along with an analysis of both steady state and transient behavior using simulation modeling.


Sub-Lethal Effects Of Hypoxia/Hypercapnia On Callinectes Sapidus In The York River Estuary, Virginia, Sandra R. Hypes Jan 1999

Sub-Lethal Effects Of Hypoxia/Hypercapnia On Callinectes Sapidus In The York River Estuary, Virginia, Sandra R. Hypes

Theses and Dissertations

This research examined effects of hypoxic environments on blue crabs, Callinectes sapidus in an estuarine environment. Hypoxic conditions were treated as a multiple stressor involving low dissolved oxygen (D.O.), increased carbon dioxide (hypercapnia), and low pH concurrently. The objectives were to: 1) identify hypoxiahypercapnia by monitoring D.O. and pH as an indicator of hypercapnia in shallow regions of the York River, 2) measure blue crab abundance, and 3) describe blue crab responses to hypoxiahypercapnia via field work at Taskinas Creek and lab measurements of respiration. Ambient D.O. and pH were positively correlated in the Taskinas Creek and York River sites …


Synthesis Of Benzoxazoles Containing Allyl Crosslinking Sites Via Claisen Rearrangements, Leslie K. Hutson Jan 1999

Synthesis Of Benzoxazoles Containing Allyl Crosslinking Sites Via Claisen Rearrangements, Leslie K. Hutson

Browse all Theses and Dissertations

The reaction of diethyl 2,5-dihydroxyterephthalate with allyl bromide/K2CO3 in DMF followed by hydrolysis provided 2,5-di(allyloxy)terephthalic acid. The conversion of 2,5-di (allyloxy)terephthalic acid to 1,4-di(2-benzoxazolyl)-2,5-di(allyloxy)benzene in PPSE was unsuccessful. However, the reaction of 1,4-di(2-benzoxazolyl)-2,5- dihydroxybenzene with allyl bromide/K2CO3 provided 1,4-di(2-benzoxazolyl)-2,5- di(allyloxy)benzene. DSC analysis indicated that 1,4-di(2-benzoxazolyl)-2,5- di(allyloxy)benzene undergoes a Claisen rearrangement to the corresponding diallyl product. The synthesis of 2-allyloxy-1,4-di(2-benzoxazolyl)benzene was carried out using 2-hydroxy-1,4-di(2-benzoxazolyl)benzene as starting material. DSC analysis was inconclusive with respect to a Claisen rearrangement. The reaction of 2-allyloxybenzoic acid with 2,2-bis(3-amino-4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane in PPSE was unsuccessful but the reaction of 2,2-bis(2-(2-hydroxyphenyl)-5-benzoxazolyl)-1,1,1,3,3,3-hexafluoropropane with allyl bromide/K2CO3 in DMF provided 2,2-bis(2-(2- …


The Cause And Consequence Of Ontogenetic Changes In Social Aggregation In New Zealand Spiny Lobsters, Mark J. Butler Iv, Alistair B. Macdiarmid, John D. Booth Jan 1999

The Cause And Consequence Of Ontogenetic Changes In Social Aggregation In New Zealand Spiny Lobsters, Mark J. Butler Iv, Alistair B. Macdiarmid, John D. Booth

Biological Sciences Faculty Publications

Ontogenetic changes in the behavior, spatial distribution, or habitat use of a species are presumably adaptations to ecological forces that differ in their effect on various life stages. The New Zealand rock lobster Jasus edwardsii is one of several species of spiny lobster that exhibits dramatic ontogenetic shifts in sociality and spatial distribution, and we tested whether such changes are adaptive. We first surveyed several natural populations of J. edwardsii to document size-specific differences in aggregation. To determine if chemical cues discharged by conspecifics promote aggregation of certain ontogenetic stages, we tested the responsiveness of lobsters of 3 ontogenetic stages …


Synthesis And Molecular Structure Of [Cpru(Pph3)(Pms)2]Otf1.3/4 C2>H4C12, Paul M. Nave, Mark Draganjac, A. W. Cordes, Tosha M. Barclay Jan 1999

Synthesis And Molecular Structure Of [Cpru(Pph3)(Pms)2]Otf1.3/4 C2>H4C12, Paul M. Nave, Mark Draganjac, A. W. Cordes, Tosha M. Barclay

Journal of the Arkansas Academy of Science

No abstract provided.


Metaphor And Understanding: The Work Of Lakoff And Johnson And Natural Language Processing, Karen M. Jakubowsky Jan 1999

Metaphor And Understanding: The Work Of Lakoff And Johnson And Natural Language Processing, Karen M. Jakubowsky

Honors Theses, 1963-2015

Do you remember your first lesson in metaphor? Most likely, you learned that it is a comparison of one thing to another, to give a more descriptive account of something. "He was an iceberg" or "time is money" are obvious metaphors. They are regarded as simply vivid expressions to explain our ideas. However, George Lakoff, professor of linguistics at the University of California, Berkeley, and Mark Johnson, professor of philosophy at the University of Oregon, assert that metaphors are much more than literary devices. In their 1980 book, Metaphors We Live By, they claim that the way we think, act, …


A Review Of The Anticoagulant Pesticide Pindone, Laurie E. Twigg, Tim J. Lowe, Gary R. Martin, Garry S. Gray Jan 1999

A Review Of The Anticoagulant Pesticide Pindone, Laurie E. Twigg, Tim J. Lowe, Gary R. Martin, Garry S. Gray

Books & book chapters

A review of the use of pindone for rabbit control in Western Australia is timely due to increased public concern over the use of this toxin, and because non-target deaths of some native Australian animals have been known to occur following its use. Pindone is one of the first generation indandione anticoagulant rodenticides which were developed in the late 1940' s. The toxicity of anticoagulants arises from their inhibition of vitamin K-dependent clotting factors in the blood. Thus therapeutic administration of vitamin K provides a reliable antidote against anticoagulant poisoning. Pindone is slow acting and works best with repeated small …


Feasibility Of Fabrication Of Heteroepitaxial Ge_X Si_{1-X}/Si(111) Structure By Pulsed Nd: Yag Laser, R. N. Al-Rawi, R. A. Ismail, R. N. Mousis Jan 1999

Feasibility Of Fabrication Of Heteroepitaxial Ge_X Si_{1-X}/Si(111) Structure By Pulsed Nd: Yag Laser, R. N. Al-Rawi, R. A. Ismail, R. N. Mousis

Turkish Journal of Physics

Heteroepitaxial Ge_x Si_{1-x} alloy layers have been formed by 10 ms and 300 \mu s laser pulse induced mixing of pure germanium films and Si(111) substrates where Ge films of thickness (500-1250) Å are thermally evaporated onto Si(111) under vacuum pressure \sim 10^{-5} Torr. The near surface of the sample then undergoes rapid melting and regrowth processes during each pulse from a free running Nd; YAG laser. The alloy layers are (4.6-6.5) \mum thick and have a Ge fraction of x = 6-8.2%.


Influence Of Electrical Field On Pulsed Laser Beam Welding Of Stainless Steel (304), Salah A. H. Fawzi̇, Raz N. Ari̇f Jan 1999

Influence Of Electrical Field On Pulsed Laser Beam Welding Of Stainless Steel (304), Salah A. H. Fawzi̇, Raz N. Ari̇f

Turkish Journal of Physics

Pulsed laser beam welding experiment were carried out on stainless steel (SUS 304), using vertical and horizontal electric fields of different intensities to study its effectiveness on the welding process, regarding depth and weld quality. Pulsed Nd: YAG laser emitting 10 ms pulses in the TEM_{00} mode at 1.06 \mu m wave length was employed, microstructure of welded zone and defect were investigated using optical and scanning electron microscopes. Tensile test and microhardness measurements were carried out to evaluate the weld quality. Welding by this method increased the efficiency tremendously and a depth increase of 85% was achieved.


The Peculiarities Of The Electrical And Thermoelectrical Properties Of P-Type Ag_2te, Ali̇ İhsan Demi̇rel, S. A. Aliev, F. F. Aliev, F. Z. Guseynov, Sali̇m Orak Jan 1999

The Peculiarities Of The Electrical And Thermoelectrical Properties Of P-Type Ag_2te, Ali̇ İhsan Demi̇rel, S. A. Aliev, F. F. Aliev, F. Z. Guseynov, Sali̇m Orak

Turkish Journal of Physics

The electrical and thermoelectrical properties of p-type Ag_2Te have been investigated. Various peculiarities were observed: the minimum (at T \approx 65 K) and maximum (at T \approx 200 K) on the temperature dependence of conductivity \sigma (T); the weak dependence of Hall coefficient R(T) (in 200-300 K range) and the maximum (at T \approx 100 K and 250 K) on the temperature dependence of thermal power \alpha_0 (T). The investigation results were interpreted by two-bands model. It is shown that mentioned peculiarities have been stimulated by the narrow gap of Ag_2Te and its temperature dependence.