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2010

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Articles 1321 - 1350 of 5375

Full-Text Articles in Engineering

High School Student Interests In Architecture, Construction, And Engineering Education, Krishna P. Kisi Aug 2010

High School Student Interests In Architecture, Construction, And Engineering Education, Krishna P. Kisi

UNLV Theses, Dissertations, Professional Papers, and Capstones

It is a common and widely held belief that the greatest influencing factor for high school students to enter an architecture-, construction-, or engineering-education program is because either their parents, relatives or friends work or have worked in the industry. However, there is little research that supports this belief. The focus of this research was to analyze characteristics and academic interests of Clark County School District (CCSD) Career and Technical Academies (CATA) students enrolled in architecture, construction and engineering (ACE) curricula.

This research analyzed data collected from a survey conducted by CCSD of their students enrolled in ACE courses. Comprehensive …


Fabrication, Characterization And Simulation Of Non-Lithographic Nanostructures And Their Potential Applications, Neelanjan Bhattacharya Aug 2010

Fabrication, Characterization And Simulation Of Non-Lithographic Nanostructures And Their Potential Applications, Neelanjan Bhattacharya

UNLV Theses, Dissertations, Professional Papers, and Capstones

The dissertation describes the formation of porous silicon through the pores of porous alumina on a silicon substrate. Porous silicon, by itself, is inherently a non-uniform material that has non-uniform optical and electronic properties. In addition, it is also mechanically fragile material requiring careful material handling. The porous silicon fabricated through the nanosized pores of porous alumina are expected to mitigate these problems, thereby enhancing commercial viability of the device. The porous silicon as well the porous alumina have been synthesized through anodisation for various parameters and also various types of anodizing electrolytes. The porous silicon, so obtained have been …


Evaluating The Impacts Of Water Conservation Policies On Water Demand, Availability And Outdoor Water Use In The Las Vegas Valley, Kamal Qaiser Aug 2010

Evaluating The Impacts Of Water Conservation Policies On Water Demand, Availability And Outdoor Water Use In The Las Vegas Valley, Kamal Qaiser

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Las Vegas Valley, located in the arid Southern Nevada region, with a growing population, limited water resources, and a prolonged drought, faces a challenge in meeting its future water needs. Southern Nevada Water Authority (SNWA), the main water management agency in the Valley, is focusing on water conservation to reduce water demand. Current water use is 945 lpcd (250 gpcd) which SNWA aims to reduce to 752 lpcd (199 gpcd) by 2035. Presently the indoor outdoor water use proportion is about 40:60 in the Valley. An important component of the Valley's supply are the return flow credits which SNWA …


Conservation Based Uncertainty Propagation In Dynamic Systems, Lillian J. Ratliff Aug 2010

Conservation Based Uncertainty Propagation In Dynamic Systems, Lillian J. Ratliff

UNLV Theses, Dissertations, Professional Papers, and Capstones

Uncertainty is present in our everyday decision making process as well as our understanding of the structure of the universe. As a result an intense and mathematically rigorous study of how uncertainty propagates in the dynamic systems present in our lives is warranted and arguably necessary. In this thesis we examine existing methods for uncertainty propagation in dynamic systems and present the results of a literature survey that justifies the development of a conservation based method of uncertainty propagation. Conservation methods are physics based and physics drives our understanding of the physical world. Thus, it makes perfect sense to formulate …


Field Measurement & Verification Of Residential Duct Leakage Methods And Cfd Analysis Of Hvac Mixing Box, Uday Vadlamani Aug 2010

Field Measurement & Verification Of Residential Duct Leakage Methods And Cfd Analysis Of Hvac Mixing Box, Uday Vadlamani

UNLV Theses, Dissertations, Professional Papers, and Capstones

The research work in this thesis is subdivided to providing the initial results of the experimental work followed by simulation work at the end. The experimental work proposes a new measurement technique for measuring total and local leakages in ducts. The experimental work in this research tries to focus effort on finding the approximate locations of leaks in the HVAC residential duct systems to direct better the effort of duct sealing. This technique can provide several advantages over existing techniques. It will eventually have a greater potential to locate leaks so that retrofitting in ducts can be focused on leaky …


A Novel Nonlithographic Method To Fabricate Nanoparticles And Its Application In Crystallization Of Amorphous Silicon Thin Films, Wen Shen Aug 2010

A Novel Nonlithographic Method To Fabricate Nanoparticles And Its Application In Crystallization Of Amorphous Silicon Thin Films, Wen Shen

UNLV Theses, Dissertations, Professional Papers, and Capstones

In recent years nanoparticles fabricated by nonlithographic techniques have shown a very promising alternative implementation to make novel electronic and photonic devices. However, the size control of these nanoparticles has been a great challenge. In this dissertation we used a custom designed ultrahigh vacuum nanocluster deposition system to investigate the size control of nanoparticles by varying different process parameters. The experimental values are compared with existing models and results are found to be in good agreement.

Silicon thin films are very important for the fabrication of a variety of devices including flat panel displays and solar cells. However, the Si …


Wind Flow Modeling For Wind Energy Analysis Of The Nellis Dunes Area In Nevada, Upendra Rangegowda Aug 2010

Wind Flow Modeling For Wind Energy Analysis Of The Nellis Dunes Area In Nevada, Upendra Rangegowda

UNLV Theses, Dissertations, Professional Papers, and Capstones

A wind energy analysis of the Nellis Dunes area in Nevada was conducted. A DEM file which contains the elevation data was used to generate the surface model and to create a 3-D mesh of the region. Local meteorological tower data collected for a period of one year was used to generate the diagnostic initial wind fields. Upper level wind fields were created using a surface boundary layer technique along with linear interpolation of the tower level wind fields. The vertical components of the velocities were adjusted using the equation of continuity. Mass consistent 3-D wind fields were then calculated …


Pattern Recognition For Fault Detection, Classification, And Localization In Electrical Power Systems, Qais Hashim Alsafasfeh Aug 2010

Pattern Recognition For Fault Detection, Classification, And Localization In Electrical Power Systems, Qais Hashim Alsafasfeh

Dissertations

The longer it takes to identify and repair a fault, the more damage may result in the electrical power system, especially in periods of peak loads, which could lead to the collapse of the system, causing the power outage to extend for a longer period and larger parts of the electrical network. Reducing the outage time and immediate restoration of service can be achieved if the fault type and location are determined in a timely and precise manner.

An integrated algorithm that is based on generating unique signatures from the electric current signal to detect, classify, and localize a fault …


Differentially Encoded Quadrature Phase Shift Key Communication And Real-Time Implementation, Robert Walton Conant Aug 2010

Differentially Encoded Quadrature Phase Shift Key Communication And Real-Time Implementation, Robert Walton Conant

Boise State University Theses and Dissertations

Robust communication methods are integral to advances in modern technology. Software defined radios (SDRs) have been the chief instruments of communication for the last three decades. Upcoming generations of wireless networks and phone systems depend on successful implementations of increasingly sophisticated software defined modulation methods. The challenges presented by encoding, modulation, signal conditioning, timing, and decision algorithms are non-trivial. Adapting to the impacts of wired and wireless channels adds further complexity.

While not comprehensive on the subject of communications, this text serves to introduce the practical concepts of binary communications, modulation methods, the digital signal processor (DSP), and software defined …


A Reconfigurable Pattern Matching Hardware Implementation Using On-Chip Ram-Based Fsm, Indrawati Gauba Aug 2010

A Reconfigurable Pattern Matching Hardware Implementation Using On-Chip Ram-Based Fsm, Indrawati Gauba

Boise State University Theses and Dissertations

The use of synthesizable reconfigurable IP cores has increasingly become a trend in System on Chip (SOC) designs. Such domain-special cores are being used for their flexibility and powerful functionality. The market introduction of multi-featured platform FPGAs equipped with on-chip memory and embedded processor blocks has further extended the possibility of utilizing dynamic reconfiguration to improve overall system adaptability to meet varying product requirements. A dynamically reconfigurable Finite State Machine (FSM) can be implemented using on-chip memory and an embedded processor. Since FSMs are the vital part of sequential hardware designs, the reconfiguration can be achieved in all designs containing …


Experimental Observations Of Active Invariance Striations In A Tank Environment, Jorge E. Quijano, Richard L. Campbell, Tobias G. Oesterlein, Lisa M. Zurk Aug 2010

Experimental Observations Of Active Invariance Striations In A Tank Environment, Jorge E. Quijano, Richard L. Campbell, Tobias G. Oesterlein, Lisa M. Zurk

Electrical and Computer Engineering Faculty Publications and Presentations

The waveguide invariant in shallow water environments has been widely studied in the context of passive sonar. The invariant provides a relationship between the frequency content of a moving broadband source and the distance to the receiver, and this relationship is not strongly affected by small perturbations in environment parameters such as sound speed or bottom features. Recent experiments in shallow water suggest that a similar range-frequency structure manifested as striations in the spectrogram exists for active sonar, and this property has the potential to enhance the performance of target tracking algorithms. Nevertheless, field experiments with active sonar have not …


Analytical Solutions For Efficient Interpretation Of Single-Well Push-Pull Tracer Tests, Junqi Huang, John A. Christ, Mark N. Goltz Aug 2010

Analytical Solutions For Efficient Interpretation Of Single-Well Push-Pull Tracer Tests, Junqi Huang, John A. Christ, Mark N. Goltz

Faculty Publications

Single-well push-pull tracer tests have been used to characterize the extent, fate, and transport of subsurface contamination. Analytical solutions provide one alternative for interpreting test results. In this work, an exact analytical solution to two-dimensional equations describing the governing processes acting on a dissolved compound during a modified push-pull test (advection, longitudinal and transverse dispersion, first-order decay, and rate-limited sorption/partitioning in steady, divergent, and convergent flow fields) is developed. The coupling of this solution with inverse modeling to estimate aquifer parameters provides an efficient methodology for subsurface characterization. Synthetic data for single-well push-pull tests are employed to demonstrate the utility …


Investigation Of The Slow- And Fast-Light Effect On The Basis Of Stimulated Brillouin Scattering For Application In Optical Communication And Information Systems., Ronny Henker Aug 2010

Investigation Of The Slow- And Fast-Light Effect On The Basis Of Stimulated Brillouin Scattering For Application In Optical Communication And Information Systems., Ronny Henker

Doctoral

In today's information age demand for ultra-fast information transfer with ultra-high bandwidths has reached extraordinary levels. Hence, the transmission in the future internet-backbone will be increasingly constrained in the network nodes. At the same time, the power consumption of the network systems will increase to unsustainable levels.

Nowadays, optical signal processing and switching can be implemented relatively easily. However, the realization of optical bu ers and short-term memories is still an unsolved challenge. The slow- and fast-light e ect has been investigated as one solution for the optical bu ering over the last few years. It means the slowing down …


Macrophages Loaded With Gold Nanoshells For Photothermal Ablation Of Glioma: An In Vitro Model, Amani Riad Makkouk Aug 2010

Macrophages Loaded With Gold Nanoshells For Photothermal Ablation Of Glioma: An In Vitro Model, Amani Riad Makkouk

UNLV Theses, Dissertations, Professional Papers, and Capstones

The current median survival of patients with glioblastoma multiforme (GBM), the most common type of glioma, remains at 14.6 months despite multimodal treatments (surgery, radiotherapy and chemotherapy). This research aims to study the feasibility of photothermal ablation of glioma using gold nanoshells that are heated upon laser irradiation at their resonance wavelength. The novelty of our approach lies in improving nanoshell tumor delivery by loading them in macrophages, which are known to be recruited to gliomas via tumor-released chemoattractive agents. Ferumoxides, superparamagnetic iron oxide (SPIO) nanoparticles, are needed as an additional macrophage load in order to visualize macrophage accumulation in …


Optimal Design Of Vehicle With Internal Space Frame Structure Subjected To High Impact Load, Jagadeep Thota Aug 2010

Optimal Design Of Vehicle With Internal Space Frame Structure Subjected To High Impact Load, Jagadeep Thota

UNLV Theses, Dissertations, Professional Papers, and Capstones

Armored military vehicles are heavily used in modern warfare. These vehicles are subjected to lethal attacks from projectiles and land mines. The shocks from these attacks may risk the safety of the occupants and damage the electronic instruments within the vehicle. Extensive research on the analysis and reduction of shocks on civilian vehicles has been performed. Fewer researchers addressed these problems in the case of military vehicles. Space frames are usually used to enhance structural strength of the vehicle while reducing its overall weight. These frames comprise of beams connected together at joints. Recently, space frames were incorporated in military …


Investigation Of Potential Pathways And Multi-Cycle Bioregeneration Of Ion-Exchange Resin Laden With Perchlorate, Mohamadali Sharbatmaleki Aug 2010

Investigation Of Potential Pathways And Multi-Cycle Bioregeneration Of Ion-Exchange Resin Laden With Perchlorate, Mohamadali Sharbatmaleki

UNLV Theses, Dissertations, Professional Papers, and Capstones

Ion-exchange (IX) is possibly the most feasible technology for perchlorate removal and perchlorate-selective and non-selective IX resins are commercially available for this purpose. The use of both resins has shortcomings. Selective resins are incinerated after one time use, and non-selective resins produce a regenerant waste stream that contains high concentration of perchlorate. A process involving directly contacting of spent IX resin containing perchlorate with perchlorate-reducing bacteria (PRB) to bioregenerate the resin has been developed and proven recently. In this process PRB biodegrade perchlorate ions which are attached to the functional groups of the resin.

Although its feasibility has been proven, …


Automated Procedures For Quantification Of Rhizosphere Physical Properties In Micro Ct Images, Natarajan S. Pillai Aug 2010

Automated Procedures For Quantification Of Rhizosphere Physical Properties In Micro Ct Images, Natarajan S. Pillai

UNLV Theses, Dissertations, Professional Papers, and Capstones

The rhizosphere, i.e. the zone of soil immediately surrounding plant roots plays a prominent role in supplying plants with water and nutrients. However, surprisingly little is known about rhizosphere physical properties and how they affect root growth, water and nutrient uptake. The lack of non-invasive and non-destructive imaging techniques necessary to observe living roots growing in undisturbed soil have been a main reason for this shortcoming. Recent advances in synchrotron X-ray micro tomography (CMT) provide the potential to directly observe soil physical properties around living roots in-situ.In this work we develop procedures for assisting scientist to study the soil properties …


Structural And Magnetic Properties Of Neodymium–Iron–Boron Clusters, Jeremy J. Anderson Jul 2010

Structural And Magnetic Properties Of Neodymium–Iron–Boron Clusters, Jeremy J. Anderson

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Using inert gas condensation techniques the properties of sputtered neodymium-iron-born clusters were investigated. A D.C. magnetron sputtering source created vaporous Nd-Fe-B which was then condensed into clusters and deposited onto silicon substrates. A composite target of Nd-Fe-B discs on an iron plate and a composite target of Nd-(Fe-Co)-B were utilized to create clusters. The clusters were coated with a carbon layer through R.F. sputtering to prevent oxidation.

Samples were investigated in the TEM and showed a size distribution with an average particle diameter of 8.11 nm. The clusters, upon deposition, were amorphous as indicated by diffuse diffraction patterns obtained through …


A Suggested Building Block Geometry Without Continuous Radial Joints Of Possible Relevance For Particle Detectors, Jim Mcgovern Jul 2010

A Suggested Building Block Geometry Without Continuous Radial Joints Of Possible Relevance For Particle Detectors, Jim Mcgovern

Articles

A geometry for concentrc shells or tubes, built-up from a single rhombohedral block type, is described. Continuous radial joints are avoided.


Eye Movements In Elite Athletes - An Index For Performance., Harshad Hegde Jul 2010

Eye Movements In Elite Athletes - An Index For Performance., Harshad Hegde

Theses and Dissertations

Introduction: In gymnastics, athletes perform twisting and flipping skills at high angular velocities. These athletes rely heavily on sensory information from the visual, proprioceptive, and vestibular systems. The vestibulo-ocular reflex (VOR) is responsible for stabilizing the visual field on the retina during head movement. To accomplish this, the eyes are reflexively moved in a direction opposite the head. In a twisting gymnast, this actually reduces the ability of gymnasts to see the landing during airborne skills. Hence it becomes necessary for the gymnasts to cancel or suppress their VOR in order to view the landing. Objective: The purpose of this …


Using Design Of Experiments And Electron Backscatter Diffraction To Model Extended Plasticity Mechanisms In Friction Stir Welded Aisi 304l Stainless Steel, Benjamin D. Nelson Jul 2010

Using Design Of Experiments And Electron Backscatter Diffraction To Model Extended Plasticity Mechanisms In Friction Stir Welded Aisi 304l Stainless Steel, Benjamin D. Nelson

Theses and Dissertations

Extended plasticity mechanisms (EPM) allow a metal to undergo extended plastic deformation without failure. These mechanisms are responsible for the extended plastic deformation characteristic of hot working processes. In this thesis it is shown that electron backscatter diffraction (EBSD) is capable of detecting EPM artifacts in the final microstructure of AISI 304L stainless steel (304L). Results also indicate that dislocation cells form in hot worked AISI 304L stainless steel. Additionally, in this study EBSD data collection and analysis is used with a design of experiments approach to model the presence of EPM artifacts in the final microstructure of friction stir …


A Genome-Wide Analysis Reveals No Nuclear Dobzhansky-Muller Pairs Of Speciation Genes Between S. Cerevisiae And S. Paradoxus, But Suggests More Complex Incompatibilities, Katy Kao, Katja Schwartz, Gavin Sherlock Jul 2010

A Genome-Wide Analysis Reveals No Nuclear Dobzhansky-Muller Pairs Of Speciation Genes Between S. Cerevisiae And S. Paradoxus, But Suggests More Complex Incompatibilities, Katy Kao, Katja Schwartz, Gavin Sherlock

Faculty Publications

The Dobzhansky-Muller (D-M) model of speciation by genic incompatibility is widely accepted as the primary cause of interspecific postzygotic isolation. Since the introduction of this model, there have been theoretical and experimental data supporting the existence of such incompatibilities. However, speciation genes have been largely elusive, with only a handful of candidate genes identified in a few organisms. The Saccharomyces sensu stricto yeasts, which have small genomes and can mate interspecifically to produce sterile hybrids, are thus an ideal model for studying postzygotic isolation. Among them, only a single D-M pair, comprising a mitochondrially targeted product of a nuclear gene …


Effect Of Mechanical Stimulation On Mesenchymal Stem Cell Seeded Cartilage Constructs, Karin Wartella Jul 2010

Effect Of Mechanical Stimulation On Mesenchymal Stem Cell Seeded Cartilage Constructs, Karin Wartella

Theses and Dissertations

Cartilage tissue engineered constructs using mesenchymal stem cells were stimulated with 3 different stimulation algorithms to achieve characteristics mimicking the superficial tangential zone of articular cartilage. The stimulation algorithm of both compression and tension without an offset had the best properties out of all the evaluated groups.


Electric Field-Free Gas Breakdown In Explosively Driven Generators, S. I. Shkuratov, Jason Baird, E. F. Talantsev, Larry L. Altgilbers Jul 2010

Electric Field-Free Gas Breakdown In Explosively Driven Generators, S. I. Shkuratov, Jason Baird, E. F. Talantsev, Larry L. Altgilbers

Mining Engineering Faculty Research & Creative Works

All known types of gas discharges require an electric field to initiate them. We are reporting on a unique type of gas breakdown in explosively driven generators that does not require an electric field.


Dynamic Placement And Signal Selection For Upfcs In Wide-Area Controlled Power Systems, Mahyar Zarghami, Mariesa Crow Jul 2010

Dynamic Placement And Signal Selection For Upfcs In Wide-Area Controlled Power Systems, Mahyar Zarghami, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

This paper deals with the problem of damping inter-area oscillations in wide-area bulk power systems using unified power flow controllers. Dynamic placement and signal selection are two important issues when FACTS devices are deployed in the system. in the paper both problems have been investigated using a Most Dominant Branches table calculated based on modal analysis which shows the influence of active powers of the branches on inter-area modes of the system. First, dynamic placement has been explained in which the best placement candidates are selected based on their influence on inter-area modes. Next the paper deals with dynamic estimation …


Embedded Processor Selection/Performance Estimation Using Fpga-Based Profiling, Fadi Obeidat Jul 2010

Embedded Processor Selection/Performance Estimation Using Fpga-Based Profiling, Fadi Obeidat

Theses and Dissertations

In embedded systems, modeling the performance of the candidate processor architectures is very important to enable the designer to estimate the capability of each architecture against the target application. Considering the large number of available embedded processors, the need has increased for building an infrastructure by which it is possible to estimate the performance of a given application on a given processor with a minimum of time and resources. This dissertation presents a framework that employs the softcore MicroBlaze processor as a reference architecture where FPGA-based profiling is implemented to extract the functional statistics that characterize the target application. Linear …


Cloud Computing For Schools, Shane O'Doherty Jul 2010

Cloud Computing For Schools, Shane O'Doherty

Dissertations

This project evaluates previous Information and Communication Technology policy and practice relating to primary schools in Ireland with a view to suggesting a better way forward in light of advances in ICT, such as the availability of fast broadband services, including fibre broadband, browser-based applications and the advent of cloud computing. Cloud computing refers to the Internet as a source of both software programs and also data retention, in effect the Internet provides the software and data services via browsers to users who may remain entirely unaware of the technology at work, uncluttered by hardware or software licensing issues or …


Research On Distribution Program Of Food Cold-Chain Logistics In Bright Speed Fresh Logistics Company, Zexin Xu Jul 2010

Research On Distribution Program Of Food Cold-Chain Logistics In Bright Speed Fresh Logistics Company, Zexin Xu

World Maritime University Dissertations

No abstract provided.


Case Study Of Cold Chain Logistics Business Of Third Party Logistics Company, Han Bao Jul 2010

Case Study Of Cold Chain Logistics Business Of Third Party Logistics Company, Han Bao

World Maritime University Dissertations

No abstract provided.


Reasonable Number Of Issuing Original Bill Of Lading, Zhongming Ren Jul 2010

Reasonable Number Of Issuing Original Bill Of Lading, Zhongming Ren

World Maritime University Dissertations

No abstract provided.