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2013

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Articles 481 - 510 of 8928

Full-Text Articles in Physical Sciences and Mathematics

Certain Fractional Integral Operators And The Generalized Incomplete Hypergeometric Functions, H. M. Srivastava, Praveen Agarwal Dec 2013

Certain Fractional Integral Operators And The Generalized Incomplete Hypergeometric Functions, H. M. Srivastava, Praveen Agarwal

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, we apply a certain general pair of operators of fractional integration involving Appell’s function F3 in their kernel to the generalized incomplete hypergeometric functions pΓq[z] and pɣq [z], which were introduced and studied systematically by Srivastava et al. in the year 2012. Some interesting special cases and consequences of our main results are also considered.

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The Mx/G/1 Queue With Unreliable Server, Delayed Repairs, And Bernoulli Vacation Schedule Under T-Policy, L. Tadj, G. Choudhury Dec 2013

The Mx/G/1 Queue With Unreliable Server, Delayed Repairs, And Bernoulli Vacation Schedule Under T-Policy, L. Tadj, G. Choudhury

Applications and Applied Mathematics: An International Journal (AAM)

In this paper we study a batch arrival queuing system. The server may break down while delivering service. However, repair is not provided immediately, rather it is delayed for a random amount of time. At the end of service, the server may process the next customer if any are available, or may take a vacation to execute some other job. Finally, the server implements the T-policy. We describe for this system an optimal management policy. Numerical examples are provided.


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New Existence Results To Solution Of Fractional Boundary Value Problems, Rahmat Darzi, Bahar Mohammadzadeh Dec 2013

New Existence Results To Solution Of Fractional Boundary Value Problems, Rahmat Darzi, Bahar Mohammadzadeh

Applications and Applied Mathematics: An International Journal (AAM)

In this article, we verify the existence of solution to boundary value problem of nonlinear fractional differential equation involving Caputo fractional derivatives. We obtain new existence results based on nonlinear alternative of Leray-Schauder type and Krasnoselskiis fixed point theorem. At the end, two illustrative examples have been presented.

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Relation Between Hilbert Algebras And Be–Algebras, A. Rezaei, A. B. Saeid, R. A. Borzooei Dec 2013

Relation Between Hilbert Algebras And Be–Algebras, A. Rezaei, A. B. Saeid, R. A. Borzooei

Applications and Applied Mathematics: An International Journal (AAM)

Hilbert algebras are introduced for investigations in intuitionistic and other non - classical logics and BE -algebra is a generalization of dual BCK -algebra. In this paper, we investigate the relationship between Hilbert algebras and BE -algebras. In fact, we show that a commutative implicative BE -algebra is equivalent to the commutative self distributive BE -algebra, therefore Hilbert algebras and commutative self distributive BE -algebras are equivalent.

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The Two-Phase Arterial Blood Flow With Or Without A Catheter And In The Presence Of A Single Or Multi Stenosis, Ani E. Garcia, Daniel N. Riahi Dec 2013

The Two-Phase Arterial Blood Flow With Or Without A Catheter And In The Presence Of A Single Or Multi Stenosis, Ani E. Garcia, Daniel N. Riahi

Applications and Applied Mathematics: An International Journal (AAM)

We consider the problem of blood flow in an artery with or without a catheter and in the presence of single or multi stenosis whose shape is based on the available experimental data for the stenosis in a human’s artery. The presence of stenosis in the artery, which locally narrows portion of the artery, can be a result of fatty materials such as cholesterol in the blood. The use of catheter is important as a standard tool for diagnosis and treatment in patience whose blood flow passage in the artery is affected adversely by the presence of the stenosis within …

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A New Approach To The Numerical Solution Of Fractional Order Optimal Control Problems, T. Akbarian, M. Keyanpour Dec 2013

A New Approach To The Numerical Solution Of Fractional Order Optimal Control Problems, T. Akbarian, M. Keyanpour

Applications and Applied Mathematics: An International Journal (AAM)

In this article, a new numerical method is proposed for solving a class of fractional order optimal control problems. The fractional derivative is considered in the Caputo sense. This approach is based on a combination of the perturbation homotopy and parameterization methods. The control function u(t) is approximated by polynomial functions with unknown coefficients. This method converts the fractional order optimal control problem to an optimization problem. Numerical results are included to demonstrate the validity and applicability of the method.

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Numerical Algorithm For Analysis Of N-Ary Subdivision Schemes, Ghulam Mustafa, Muhammad Zahid Dec 2013

Numerical Algorithm For Analysis Of N-Ary Subdivision Schemes, Ghulam Mustafa, Muhammad Zahid

Applications and Applied Mathematics: An International Journal (AAM)

The analysis for continuity of limit curves generated by m-point n-ary subdivision schemes is presented for m, n ≥ 2. The analysis is based on the study of corresponding differences and divided difference schemes. A numerical algorithm is introduced which computes the continuity and higher order divided differences of schemes in an efficient way. It is also free from polynomial factorization and division unlike the well-known Laurent polynomial algorithm for analysis of schemes which depends on polynomial algebraic operations. It only depends on the arithmetic operations.

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Exact Traveling Wave Solutions Of Nonlinear Pdes In Mathematical Physics Using The Modified Simple Equation Method, E. M. E. Zayed, A. H. Arnous Dec 2013

Exact Traveling Wave Solutions Of Nonlinear Pdes In Mathematical Physics Using The Modified Simple Equation Method, E. M. E. Zayed, A. H. Arnous

Applications and Applied Mathematics: An International Journal (AAM)

In this article, we apply the modified simple equation method to find the exact solutions with parameters of the (1+1)-dimensional nonlinear Burgers-Huxley equation, the (2+1) dimensional cubic nonlinear Klein-Gordon equation and the (2+1)-dimensional nonlinear Kadomtsev- Petviashvili-Benjamin-Bona-Mahony (KP-BBM) equation. The new exact solutions of these three equations are obtained. When these parameters are given special values, the solitary solutions are obtained.

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Numerical Solution Of Fuzzy Arbitrary Order Predator-Prey Equations, Smita Tapaswini, S. Chakraverty Dec 2013

Numerical Solution Of Fuzzy Arbitrary Order Predator-Prey Equations, Smita Tapaswini, S. Chakraverty

Applications and Applied Mathematics: An International Journal (AAM)

This paper seeks to investigate the numerical solution of fuzzy arbitrary order predator-prey equations using the Homotopy Perturbation Method (HPM). Fuzziness in the initial conditions is taken to mean convex normalised fuzzy sets viz. triangular fuzzy number. Comparisons are made between crisp solution given by others and fuzzy solution in special cases. The results obtained are depicted in plots and tables to demonstrate the efficacy and powerfulness of the methodology.

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The Log-Beta Generalized Half-Normal Regression Model, Rodrigo R. Pescim, Edwin M. M. Ortega, Gauss M. Cordeiro, Clarice G. B. Demtrio, Gholamhossein Hamedani Dec 2013

The Log-Beta Generalized Half-Normal Regression Model, Rodrigo R. Pescim, Edwin M. M. Ortega, Gauss M. Cordeiro, Clarice G. B. Demtrio, Gholamhossein Hamedani

Mathematics, Statistics and Computer Science Faculty Research and Publications

We introduce a log-linear regression model based on the beta generalized half-normal distribution (Pescim et al., 2010). We formulate and develop a log-linear model using a new distribution so-called the log-beta generalized half normal distribution. We derive expansions for the cumulative distribution and density functions which do not depend on complicated functions. We obtain formal expressions for the moments and moment generating function. We characterize the proposed distribution using a simple relationship between two truncated moments. An advantage of the new distribution is that it includes as special sub-models classical distributions reported in the lifetime literature. We also show that …

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Glacier Slip And Seismicity Induced By Surface Melt, Peter L. Moore, J. Paul Winberry, Neal R. Iverson, Knut A. Christianson, Sridhar Anandakrishnan, Miriam Jackson, Mark E. Mathison, Denis Cohen Dec 2013

Glacier Slip And Seismicity Induced By Surface Melt, Peter L. Moore, J. Paul Winberry, Neal R. Iverson, Knut A. Christianson, Sridhar Anandakrishnan, Miriam Jackson, Mark E. Mathison, Denis Cohen

All Faculty Scholarship for the College of the Sciences

Many of the key processes governing fast glacier flow involve interaction between a glacier and its basal hydrological system, which is hidden from direct observation. Passive seismic monitoring has shown promise as a tool for remotely monitoring basal processes, but lack of glacier-bed access prevents clear understanding of the relationships between subglacial processes and corresponding seismic emissions. Here we describe direct measurements of basal hydrology, sliding, and broadband seismicity made in a unique subglacial facility in Norway during the onset of two summer melt seasons. In the most pronounced of these episodes, rapid delivery of surface meltwater to the bed …

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Securing Information Technology In Healthcare, Denise Anthony, Andrew T. Campbell, Thomas Candon, Andrew Gettinger, David Kotz, Lisa A. Marsch, Andrés Molina-Markham, Karen M. Page, Sean W. Smith, Carl A. Gunter, M. Eric Johnson Dec 2013

Securing Information Technology In Healthcare, Denise Anthony, Andrew T. Campbell, Thomas Candon, Andrew Gettinger, David Kotz, Lisa A. Marsch, Andrés Molina-Markham, Karen M. Page, Sean W. Smith, Carl A. Gunter, M. Eric Johnson

Dartmouth Scholarship

Information technology (IT) has great potential to improve healthcare quality while also improving efficiency, and thus has been a major focus of recent healthcare reform efforts. However, developing, deploying and using IT that is both secure and genuinely effective in the complex clinical, organizational and economic environment of healthcare is a significant challenge. Further, it is imperative that we better understand the privacy concerns of patients and providers, as well as the ability of current technologies, policies, and laws to adequately protect privacy. The Securing Information Technology in Healthcare (SITH) workshops were created to provide a forum to discuss security …

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Random Search Models Of Foraging Behavior: Theory, Simulation, And Observation, Ben C. Nolting Dec 2013

Random Search Models Of Foraging Behavior: Theory, Simulation, And Observation, Ben C. Nolting

Department of Mathematics: Dissertations, Theses, and Student Research

Many organisms, from bacteria to primates, use stochastic movement patterns to find food. These movement patterns, known as search strategies, have recently be- come a focus of ecologists interested in identifying universal properties of optimal foraging behavior. In this dissertation, I describe three contributions to this field. First, I propose a way to extend Charnov's Marginal Value Theorem to the spatially explicit framework of stochastic search strategies. Next, I describe simulations that compare the efficiencies of sensory and memory-based composite search strategies, which involve switching between different behavioral modes. Finally, I explain a new behavioral analysis protocol for identifying the …

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An Analysis Of Peer-To-Peer Distributed Hash Algorithms In Improving Fault Tolerance In The Hadoop Running Environment, Benjamin R. Knaus Dec 2013

An Analysis Of Peer-To-Peer Distributed Hash Algorithms In Improving Fault Tolerance In The Hadoop Running Environment, Benjamin R. Knaus

Honors Theses

Cloud computing is a “new frontier” in the world of computing. One of the cloud architectures widely used is the Hadoop running environment. Hadoop consists of many parts—including MapReduce, TaskTrackers, and JobTrackers. Right now, there is no fault-tolerance for JobTrackers in Hadoop. This paper analyzes four different distributed hash algorithms (Pastry, Tapestry, CAN, and Chord) that could be implemented inside Hadoop to improve JobTracker fault-tolerance. We recommend Chord as the best suited for integration and improvement of Hadoop.

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An Insight Into Asymmetric Synthesis And Bioorganic Applications Of Novel Cα- Methyl-Lysine, - Proline, - Nipocotic Acid Analogues, Souvik Banerjee Dec 2013

An Insight Into Asymmetric Synthesis And Bioorganic Applications Of Novel Cα- Methyl-Lysine, - Proline, - Nipocotic Acid Analogues, Souvik Banerjee

Dissertations

Prochiral malonic diesters consisting of a quaternary carbon center have been successfully converted into a different set of tBoc-Fmoc-α2,2-methyllysine-OH analogues through chiral malonic half-ester intermediates achieved via enzymatic (Pig Liver Esterase, PLE) hydrolysis. The selection of chiral half-ester intermediates, which vary from 1 to 6 methylene units in the side chain, are achieved in high optical purity (92% - 97% ee) and in good yields (65% - 72%). The PLE hydrolysis of malonic diesters with a variety of side chain lengths observed to obey the Jones’s PLE model as evidenced from the stereochemical configurations of the resulting chiral half-esters. The …

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Design And Synthesis Of Flexible And Functional Polybenzoxazine Thin Films, Austin David Baranek Dec 2013

Design And Synthesis Of Flexible And Functional Polybenzoxazine Thin Films, Austin David Baranek

Dissertations

Polybenzoxazines offer the unique ability to incorporate a variety of properties and functionality into a single polymer network through simple synthetic techniques. However, within benzoxazine materials exist certain drawbacks of which brittleness is the primary issue when exploring thin film applications. This brittleness leads to poor mechanical stability and would reduce the lifetime of any device sought after. It is, however, through the simplistic nature of the benzoxazine monomer synthesis that the mechanical stability could be addressed chemically, avoiding the complications of using rubber toughening agents or plasticizers. The monomer synthesis offers tailorability of both the phenol and amine to …

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An Early And Comprehensive Millimetre And Centimetre Wave And X-Ray Study Of Sn 2011dh: A Non-Equipartition Blast Wave Expanding Into A Massive Stellar Wind, Assaf Horesh, Christopher Stockdale, Derek B. Fox, Dale A. Frail, John Carpenter, S. R. Kulkarni, Eran O. Ofek, Avishay Gal-Yam, Mansi M. Kasliwal, Iair Arcavi, Robert Quimby, S. Bradley Cenko, Peter E. Nugent, Joshua S. Bloom, Nicholas M. Law, Dovi Poznanski, Evgeny Gorbikov, David Polishook, Ofer Yaron, Stuart Ryder, Kurt W. Weiler, Franz Bauer, Schuyler D. Van Dyk, Stefan Immler, Nino Panagia, Dave Pooley, Namir Kassim Dec 2013

An Early And Comprehensive Millimetre And Centimetre Wave And X-Ray Study Of Sn 2011dh: A Non-Equipartition Blast Wave Expanding Into A Massive Stellar Wind, Assaf Horesh, Christopher Stockdale, Derek B. Fox, Dale A. Frail, John Carpenter, S. R. Kulkarni, Eran O. Ofek, Avishay Gal-Yam, Mansi M. Kasliwal, Iair Arcavi, Robert Quimby, S. Bradley Cenko, Peter E. Nugent, Joshua S. Bloom, Nicholas M. Law, Dovi Poznanski, Evgeny Gorbikov, David Polishook, Ofer Yaron, Stuart Ryder, Kurt W. Weiler, Franz Bauer, Schuyler D. Van Dyk, Stefan Immler, Nino Panagia, Dave Pooley, Namir Kassim

Physics Faculty Research and Publications

Only a handful of supernovae (SNe) have been studied in multiwavelengths from the radio to X-rays, starting a few days after the explosion. The early detection and classification of the nearby Type IIb SN 2011dh/PTF 11eon in M51 provides a unique opportunity to conduct such observations. We present detailed data obtained at one of the youngest phase ever of a core-collapse SN (days 3–12 after the explosion) in the radio, millimetre and X-rays; when combined with optical data, this allows us to explore the early evolution of the SN blast wave and its surroundings. Our analysis shows that the expanding …

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Beyond The Chemistry Web, Robert A. Buchanan Dec 2013

Beyond The Chemistry Web, Robert A. Buchanan

Sci-Tech News

No abstract provided.

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Tablet And Face-To-Face Hybrid Professional Development: Providing Earth Systems Science Educators Authentic Research Opportunities Through The Globe Program At Purdue University, Kristin Wegner, Benjamin D. Branch, Steven Smith Dec 2013

Tablet And Face-To-Face Hybrid Professional Development: Providing Earth Systems Science Educators Authentic Research Opportunities Through The Globe Program At Purdue University, Kristin Wegner, Benjamin D. Branch, Steven Smith

Libraries Faculty and Staff Presentations

No abstract provided.

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Implementation Of Freedm Smart Grid Distributed Load Balancing Using Iec 61499 Function Blocks, Sandeep Patil, Valeriy Vyatkin, Bruce M. Mcmillin Dec 2013

Implementation Of Freedm Smart Grid Distributed Load Balancing Using Iec 61499 Function Blocks, Sandeep Patil, Valeriy Vyatkin, Bruce M. Mcmillin

Computer Science Faculty Research & Creative Works

This paper presents implementation of one of the Distributed Grid Intelligence (DGI) applications: Load Balancing, using the IEC61499 architecture. This enables system level design of distributed load balancing application with a direct pathway to deployment to hardware. The use of IEC 61499 improves scalability, re-configurability and maintainability of automation software. The application was deployed to commercial programmable automation devices and embedded controller (ARM based TS-7800). The application was verified using co-simulation approach: control and power system simulated using Matlab on PC networked with the number of distributed hardware running load balance algorithm. The use of IEC 61499 facilitates deployment of …

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Differences In Internet Usage Patterns With Stress And Anxiety Among College Students, Levi Malott, Sai Preethi Vishwanathan, Sriram Chellappan Dec 2013

Differences In Internet Usage Patterns With Stress And Anxiety Among College Students, Levi Malott, Sai Preethi Vishwanathan, Sriram Chellappan

Computer Science Faculty Research & Creative Works

Stress and Anxiety negatively affect mental health and can lead a number of debilitating impacts to overall health and wellbeing. In the recent past, adolescents are becoming increasingly afflicted with Stress and Anxiety. In this paper, we report our findings on a six-week study of 70 students at a college campus on associations between Stress and Anxiety with respect to Internet usage of students. Using Cisco NetFlow records, on-campus Internet usage of students was collected continuously and unobtrusively in a privacy-preserving manner. Using the Depression Anxiety and Stress Scale (DASS), students were separated based on normal scores and high scores …

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Exposing And Mitigating Privacy Loss In Crowdsourced Survey Platforms, Thivya Kandappu, Vijay Sivaraman, Arik Friedman, Roksana Borell Dec 2013

Exposing And Mitigating Privacy Loss In Crowdsourced Survey Platforms, Thivya Kandappu, Vijay Sivaraman, Arik Friedman, Roksana Borell

Research Collection School Of Computing and Information Systems

Crowdsourcing platforms such as Amazon Mechanical Turk and Google Consumer Surveys can profile users based on their inputs to online surveys. In this work we first demonstrate how easily user privacy can be compromised by collating information from multiple surveys. We then propose, develop, and evaluate a crowdsourcing survey platform called Loki that allows users to control their privacy loss via atsource obfuscation.

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Factors Influencing Research Contributions And Researcher Interactions In Software Engineering: An Empirical Study, Subhajit Datta, A. S. M. Sajeev, Santonu Sarkar, Nishant Kumar Dec 2013

Factors Influencing Research Contributions And Researcher Interactions In Software Engineering: An Empirical Study, Subhajit Datta, A. S. M. Sajeev, Santonu Sarkar, Nishant Kumar

Research Collection School Of Computing and Information Systems

Research into software engineering (SE) education is largely concentrated on teaching and learning issues in coursework programs. This paper, in contrast, provides a meta analysis of research publications in software engineering to help with research education in SE. Studying publication patterns in a discipline will assist research students and supervisors gain a deeper understanding of how successful research has occurred in the discipline. We present results from a large scale empirical study covering over three and a half decades of software engineering research publications. We identify how different factors of publishing relate to the number of papers published as well …

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An Integrated Model Of Team Motivation And Worker Skills For A Computer-Based Project Management Simulation, Wee Leong Lee Dec 2013

An Integrated Model Of Team Motivation And Worker Skills For A Computer-Based Project Management Simulation, Wee Leong Lee

Research Collection School Of Computing and Information Systems

In this paper, I shall propose an integrated model of worker skills and team motivation for a computer-based simulation game that can be used to provide experiential learning to students. They can act as project managers here without being burdened by the costs and risks associated with unsuccessful projects. I shall present an approach of classifying skills into five different types (relevant to IT projects) and apply a five-point competency scale to each skill type. The Pearson Correlation will be applied to the scores of each skill type to generate an efficiency index that will characterize the effectiveness of a …

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Gfsa Encodes A Novel Galactofuranosyltransferase Involved In Biosynthesis Of Galactofuranose Antigen Of O-Glycan In Aspergillus Nidulans And Aspergillus Fumigatus, Yuji Komachi, Shintaro Hatakeyama, Haruka Motomatsu, Taiki Futagami, Karina Kizjakina, Pablo Sobrado, Keisuke Ekino, Kaoru Takegawa, Masatoshi Goto, Yoshiyuki Nomura, Takuji Oka Dec 2013

Gfsa Encodes A Novel Galactofuranosyltransferase Involved In Biosynthesis Of Galactofuranose Antigen Of O-Glycan In Aspergillus Nidulans And Aspergillus Fumigatus, Yuji Komachi, Shintaro Hatakeyama, Haruka Motomatsu, Taiki Futagami, Karina Kizjakina, Pablo Sobrado, Keisuke Ekino, Kaoru Takegawa, Masatoshi Goto, Yoshiyuki Nomura, Takuji Oka

Chemistry Faculty Research & Creative Works

Summary: The cells wall of filamentous fungi in the genus Aspergillus has galactofuranose (Galf)-containing polysaccharides and glycoconjugates, including O-glycans, N-glycans, fungal-type galactomannan and glycosylinositolphosphoceramide, which are important for cell wall integrity. Here, we attempted to identify galactofuranosyltransferases that couple Galf monomers onto other wall components in Aspergillus nidulans. Using reverse-genetic and biochemical approaches, we identified that the AN8677 gene encoded a galactofuranosyltransferase, which we called GfsA, involved in Galf antigen biosynthesis. Disruption of gfsA reduced binding of β-Galf-specific antibody EB-A2 to O-glycosylated WscA protein and galactomannoproteins. The results of an in-vitroGalf antigen synthase assay revealed that GfsA has β1,5- or …

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Influence Of Microstructure On The Propagation Of Fatigue Cracks In Inconel 617, Benjiman Michael Albiston Dec 2013

Influence Of Microstructure On The Propagation Of Fatigue Cracks In Inconel 617, Benjiman Michael Albiston

Boise State University Theses and Dissertations

Inconel 617 is a candidate material for use in the intermediate heat exchanger of the Next Generation Nuclear Plant. Because of the high temperatures and the fluctuations in stress and temperature, the fatigue behavior of the material is important to understand. The goal of this study was to determine the influences of the microstructure during fatigue crack propagation. For this investigation, Inconel 617 compact tension samples, fatigue tested by Julian Benz at the Idaho National Laboratory, were obtained. The testing conditions included two environments at 650 °C (lab air and impure-He) and varied testing parameters including: loading waveform (triangular, trapezoidal), …

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Assessing Growth Response To Climate Controls In A Great Basin Artemisia Tridentata Plant Community, Lorenzo F. Apodaca Dec 2013

Assessing Growth Response To Climate Controls In A Great Basin Artemisia Tridentata Plant Community, Lorenzo F. Apodaca

UNLV Theses, Dissertations, Professional Papers, and Capstones

An assessment of the growth response of key vegetative species to climatic variability is vital to identifying possible local impacts on ecosystems faced with imminent climate change. With current climate projections in Nevada predicting a shift to an even more arid climate with greater year-to-year variability, the imperative exists to identify the effects of specific climatic controls on plant growth and to research methods to assess large-scale vegetative changes, especially in more remote areas where readily available data sets may be lacking. This study utilized annual growth ring indices constructed from big sagebrush (Artemisia tridentatassp.tridentata) stems collected in Spring Valley, …

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Exploring The Implications Of Tutor Negativity Towards A Synthetic Agent In A Learning-By-Teaching Environment, Ma. Mercedes T. Rodrigo Dec 2013

Exploring The Implications Of Tutor Negativity Towards A Synthetic Agent In A Learning-By-Teaching Environment, Ma. Mercedes T. Rodrigo

Department of Information Systems & Computer Science Faculty Publications

We examine the implications of negativity in free-form dialogue between student tutors and a synthetic agent in APLUS, a learning-by-teaching online learning environment for Algebra. We attempt to determine whether the negativity of a student tutor's discourse with the agent indicates that the student is learning more or less of the material and whether the feedback they give the synthetic agent is more or less accurate. We found a weak negative correlation between tutor negativity and learning gains and a strong negative correlation between tutor negativity and accuracy of feedback. Negativity might indeed indicate that student tutors lack mastery of …

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The Computation Of Fluid Velocity In A Closed Cavity With A Moving Lid, Daniel A. Montez Dec 2013

The Computation Of Fluid Velocity In A Closed Cavity With A Moving Lid, Daniel A. Montez

Theses and Dissertations - UTB/UTPA

We consider a cavity filled with fluid whose three sides are stationary and the lid at the top is moving at a constant speed. The flow in the cavity is modeled using the conservation of mass and momentum equations with proper boundary conditions. We compute the fluid velocity for the steady state case using the finite element method. We seek the weak formulation and develop a finite element model based on the Galerkin method. Furthermore we use the penalty function method to modify our weak formulation to eliminate the pressure. The Gaussian quadrature method is used to evaluate our integrals …

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Reduction Of Nitroaromatic Compounds With Sodium Borohydride Using Transition Metal Sulfides, Samuel Pina Jr. Dec 2013

Reduction Of Nitroaromatic Compounds With Sodium Borohydride Using Transition Metal Sulfides, Samuel Pina Jr.

Theses and Dissertations - UTB/UTPA

The following systems: NaBH4/Fe3S4, NaBH4/Co3S4, NaBH4/NiS, NaBH4/CuS, and NaBH4/ZnS, were investigated for their nitro reducing abilities. Quantitative conversions were observed for the reduction of nitrobenzene with NaBH4/Co3S4 and NaBH4/NiS systems as opposed to only 9% conversion without any catalyst, representing a ten-fold increase in the reducing ability of NaBH4. In ethanol, various nitroaromatic compounds were also successfully reduced in moderate to high yields with 3 molar equivalents of NaBH4, demonstrating a mild alternative for the effective reduction of nitroaromatic compounds to their corresponding aryl amines. Screening of catalysts was carried out using gas chromatography. All products were characterized using 1 …

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