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Articles 101911 - 101940 of 198087

Full-Text Articles in Engineering

Comprehensive Neural Network Forecasting System For Ground Level Ozone In Multiple Regions, Gautam Raghavendra Eapi Dec 2015

Comprehensive Neural Network Forecasting System For Ground Level Ozone In Multiple Regions, Gautam Raghavendra Eapi

Civil Engineering Dissertations - Archive

A comprehensive neural network daily maximum 8 hour-ozone forecasting model was developed based on five years of data (2010-2014) collected from 50 monitoring sites from the Dallas Fort Worth, Houston-Galveston-Brazoria, Los Angeles, San Joaquin and San Diego regions. This work represents the first neural network developed to forecast ozone in multiple regions, as well as multiple sites in the same region. Previous studies have developed separate neural network models to forecast ozone at each location. Two stages of feature selection were applied to reduce input vector dimension and redundancy. These are Piecewise Linear Orthonormal Floating Search (PLOFS), and Karhunen - …


Evapoporometry: An Effective Analytical Technique For Membrane Pore Size Characterization Of Hollow Fiber Membranes, Alex J. Moix Dec 2015

Evapoporometry: An Effective Analytical Technique For Membrane Pore Size Characterization Of Hollow Fiber Membranes, Alex J. Moix

Chemical Engineering Undergraduate Honors Theses

A new analytical technique called evapoporometry has shown to be an effective and inexpensive method for membrane pore size characterization. This technique is based on the correlation between vapor pressure and pore size as described by the Kelvin equation. Evapoporometry has many advantages over tradition pore size characterization techniques. This technique allows for large sample sizes, uses minimal equipment, is capable of analyzing membranes within a wide range of pore sizes, and provides a highly descriptive representation of the pore distribution. This research looks at the application of evapoporometry as a technique for characterization of hollow fiber membranes. Using the …


Mechanical Reliability Of Porous Low-K Dielectrics For Advanced Interconnect: Study Of The Instability Mechanisms In Porous Low-K Dielectrics And Their Mediation Through Inert Plasma Induced Re-Polymerization Of The Backbone Structure, Yoonki Sa Dec 2015

Mechanical Reliability Of Porous Low-K Dielectrics For Advanced Interconnect: Study Of The Instability Mechanisms In Porous Low-K Dielectrics And Their Mediation Through Inert Plasma Induced Re-Polymerization Of The Backbone Structure, Yoonki Sa

Material Science and Engineering Dissertations - Archive

Continuous scaling down of critical dimensions in interconnect structures requires the use of ultralow dielectric constant (k) films as interlayer dielectrics to reduce resistance-capacitance delays. Porous carbon-doped silicon oxide (p-SiCOH) dielectrics have been the leading approach to produce these ultralow-k materials. However, embedding of porosity into dielectric layer necessarily decreases the mechanical reliability and increases its susceptibility to adsorption of potentially deleterious chemical species during device fabrication process. Among those, exposure of porous-SiCOH low-k (PLK) dielectrics to oxidizing plasma environment causes the increase in dielectric constant and their vulnerability to mechanical instability of PLKs due to the loss of methyl …


Nebraska Data Collection, Keyvan Zare Rami, Yong-Rak Kim Dec 2015

Nebraska Data Collection, Keyvan Zare Rami, Yong-Rak Kim

Nebraska Department of Transportation: Research Reports

Automated pavement performance data collection is a method that uses advanced technology to collect detailed road surface distress information at traffic speed. Agencies are driven to use automated survey techniques to enhance or replace their current manual distress survey because of the advantages of objective measurements, safety benefits, and reduced measurement time. As agencies move toward the transition to fully automated data collection methods, there are common concerns regarding how the output of the new method will match the current manual survey ratings and how they will be adopted into the existing Pavement Management System (PMS). This study evaluates the …


Development Of A Semicircular Bend (Scb) Test Method For Performance Testing Of Nebraska Asphalt Mixtures, Gabriel Nsengiyumva, Yong-Rak Kim, Taesun You Dec 2015

Development Of A Semicircular Bend (Scb) Test Method For Performance Testing Of Nebraska Asphalt Mixtures, Gabriel Nsengiyumva, Yong-Rak Kim, Taesun You

Nebraska Department of Transportation: Research Reports

No abstract provided.


Mechanical Properties Of Interpenetrating Phase Composites Using Open-Cell Al Foams With Natural Rubber And Polyethylene, Kunmutta Angamnuaysiri, Seksak Asavavisithchai Dec 2015

Mechanical Properties Of Interpenetrating Phase Composites Using Open-Cell Al Foams With Natural Rubber And Polyethylene, Kunmutta Angamnuaysiri, Seksak Asavavisithchai

Journal of Metals, Materials and Minerals

Interpenetrating phase composites (IPCs) were produced by conventional casting process, in vacuum atmosphere, using open-cell Al foams as matrix, and filled with either natural rubber or polyethylene. Mechanical properties of IPCs strongly depends on types of polymeric phases. It is found that the IPCs with polyethylene show an increase in compressive strength as well as failure strain. However, a large decrease of compressive strength is observed in the IPCs with natural rubber, as a result of cracks along the interface between Al foam and the rubber. These cracks are distributed throughout foam structure in the IPCs.


Microstructure And X-Ray Diffraction Analysis Of Al-Cu Couples Diffused At High Temperature, Jaime Hinojosa-Torres, Juan Manuelaceves-Hernández, Andres Herrera-Vázquez, Victor Manuelcastaño-Meneses Dec 2015

Microstructure And X-Ray Diffraction Analysis Of Al-Cu Couples Diffused At High Temperature, Jaime Hinojosa-Torres, Juan Manuelaceves-Hernández, Andres Herrera-Vázquez, Victor Manuelcastaño-Meneses

Journal of Metals, Materials and Minerals

By employing a thermal field of 813 K, couples of Al with Cu were welded as consequence of the atomic diffusion. The periods of permanency inside the field were 200, 320 and 480 hours. After the periods of test, SEM observations show the formation of two contiguous plate likes (~15 to 30 micrometres, width) that they are in normal position to the concentration gradient. By utilizing elemental analyses and X-ray diffraction techniques one plate like was identified as the h2 phase (CuAl) and the other one as the q phase (CuAl2) of the aluminium-copper system. Immediate to the q plate …


Spatial Variability Of Soil Velocity Using Passive Surface Wave Testing, Daniel Raymond Wagstaffe Dec 2015

Spatial Variability Of Soil Velocity Using Passive Surface Wave Testing, Daniel Raymond Wagstaffe

Master's Theses

Lifelines such as highways, pipelines, telecommunication lines, and powerlines provide communities with vital services, and their functionality is dependent upon the foundation soil that supports them. However, when designing the infrastructure, it can be difficult to know where to test the soil in order to give spatially representative sampling, particularly for long, lifeline structures. Finding this distance requires knowledge of the spatial correlation and/or the spatial variability of the soil parameter (stiffness, cohesion, etc.). But this correlation distance is not typically found in practice because it requires large amounts of data and the costs of retrieving that data can be …


Application Of Starch-Based Nanoparticle Colloidal Dispersion In Curtain Coating, Ting Chen Dec 2015

Application Of Starch-Based Nanoparticle Colloidal Dispersion In Curtain Coating, Ting Chen

Dissertations

In this research, a conventional petro-based latex was partially replaced with a biobased latex in a curtain coating. A common petro-based rheology modifier used in curtain coatings, which is relatively costly and difficult to disperse, was also replaced with two inorganic rheology modifiers. The influence of these materials on coating rheology and curtain stability was thoroughly examined.

In the rheological study, the interactions between biopolymer nanoparticles and inorganic rheology modifiers were found to improve the rheological properties of the biobased latex coatings. Changes in the rheological properties of the coatings were found to depend on the type of rheology modifier …


Numerical Simulation And Modeling Of Combustion In Scramjets, Ryan James Clark Dec 2015

Numerical Simulation And Modeling Of Combustion In Scramjets, Ryan James Clark

Dissertations

In the last fifteen years the development of a viable scramjet has quickly approached the following long term goals: responsive sub-orbital space access; long-range, prompt global strike; and high-speed transportation. Nonetheless, there are significant challenges that need to be resolved. These challenges include high skin friction drag and high heat transfer rates, inherent to vehicles in sustained, hypersonic flight. Another challenge is sustaining combustion. Numerical simulation and modeling was performed to provide insight into reducing skin friction drag and sustaining combustion.

Numerical simulation was used to investigate boundary layer combustion, which has been shown to reduce skin friction drag. The …


Development Of A Capacity Deployment Model For Disrupted Supply Chain Networks, James D. Burns Dec 2015

Development Of A Capacity Deployment Model For Disrupted Supply Chain Networks, James D. Burns

Dissertations

The increasing complexity of modern supply chains is widely accepted as one of the many drivers of risk that can leave organizations vulnerable to the effects of a disruption. This acceptance has contributed to an emerging interest in Supply Chain Resilience in the literature. Resilient supply chains are able to both resist the effects of a disruption and recover efficiently if the disruption is severe. This new body of literature is still in a formative phase and has thus far focused on defining Supply Chain Resilience, proposing frameworks for its implementation, exploring factors that contribute to resilience, and investigating methods …


Novel Software Defined Radio Architecture With Graphics Processor Acceleration, Lalith Narasimhan Dec 2015

Novel Software Defined Radio Architecture With Graphics Processor Acceleration, Lalith Narasimhan

Dissertations

Wireless has become one of the most pervasive core technologies in the modern world. Demand for faster data rates, improved spectrum efficiency, higher system access capacity, seamless protocol integration, improved security and robustness under varying channel environments has led to the resurgence of programmable software defined radio (SDR) as an alternative to traditional ASIC based radios. Future SDR implementations will need support for multiple standards on platforms with multi-Gb/s connectivity, parallel processing and spectrum sensing capabilities. This dissertation implemented key technologies of importance in addressing these issues namely development of cost effective multi-mode reconfigurable SDR and providing a framework to …


Hvdc Systems Fault Analysis Using Various Signal Processing Techniques, Benish Paily Dec 2015

Hvdc Systems Fault Analysis Using Various Signal Processing Techniques, Benish Paily

Doctoral

The detection and fast clearance of faults are important for the safe and optimal operation of HVDC systems. In HVDC systems, various types of AC faults (rectifier & inverter side) and DC faults can occur. It is therefore necessary to detect the faults and classify them for better protection and diagnostics purposes. Various techniques for fault detection and classification in HVDC systems using signal processing techniques are presented and investigated in this research work. In this research work, it is shown that the wavelet transformation can effectively detect abrupt changes in system signals which are indicative of a fault. This …


When 1 + 1 > 2: Nanostructured Composites For Hard Tissue Engineering Applications, Vuk Uskoković Dec 2015

When 1 + 1 > 2: Nanostructured Composites For Hard Tissue Engineering Applications, Vuk Uskoković

Pharmacy Faculty Articles and Research

Multicomponent, synergistic and multifunctional nanostructures have taken over the spotlight in the realm of biomedical nanotechnologies. The most prospective materials for bone regeneration today are almost exclusively composites comprising two or more components that compensate for the shortcomings of each one of them alone. This is quite natural in view of the fact that all hard tissues in the human body, except perhaps the tooth enamel, are composite nanostructures. This review article highlights some of the most prospective breakthroughs made in this research direction, with the hard tissues in main focus being those comprising bone, tooth cementum, dentin and enamel. …


A Platform For Fast Detection Of Let-7 Micro Rna Using Polyaniline Fluorescence And Image Analysis Techniques, Partha P. Sengupta Dec 2015

A Platform For Fast Detection Of Let-7 Micro Rna Using Polyaniline Fluorescence And Image Analysis Techniques, Partha P. Sengupta

Master's Theses

The project describes a new strategy for transducing hybridization events through modulating intrinsic properties of the electroconductive polymer polyaniline (PANI). When DNA based probes electrostatically interact with PANI, its fluorescence properties are increased, a phenomenon that can be enhanced by UV irradiation. Hybridization of target nucleic acids results in dissociation of probes causing PANI fluorescence to return to basal levels. By monitoring restoration of base PANI fluorescence as little as 10-11 M (10 pM) of target oligonucleotides could be detected within 15 minutes of hybridization. Detection of complementary oligos was specific, with introduction of a single mismatch failing to …


Exploring Emerging Technologies For The Built Environment Circa 2015 For Use In Architectural Engineering And Related Majors, Connor J. Hanlon Dec 2015

Exploring Emerging Technologies For The Built Environment Circa 2015 For Use In Architectural Engineering And Related Majors, Connor J. Hanlon

Architectural Engineering

For this senior project I am seeking to combine my knowledge of Structural Engineering with Construction Management. For this task, I have decided to look at Building Information Modeling (BIM). In this project I investigate the BIM tools Trimble Tekla Structures and Autodesk Navis- works Manage. Tekla is a modeling, fabrication, and design program. Navisworks is a visualiza- tion and Clash Detection tool. For this project I have identiÅied two main goals relating to Navis- works and Tekla:

  1. Create content to allow students and professors learn how to use Tekla and Navisworks

  2. Determine the capabilities of these softwares, and Åigure …


Tron 2.0 - The Experience, Alecsandro G. Vitale, Alexander W. Billings, Jordan Delfino, William Beechinor, Kelly Rorden Dec 2015

Tron 2.0 - The Experience, Alecsandro G. Vitale, Alexander W. Billings, Jordan Delfino, William Beechinor, Kelly Rorden

Architectural Engineering

The goal of this senior project was to come up with a structural-engineering-related schematic design for a roller coaster to be installed in Disneyland called TRON 2.0: The Experience. This involved looking at both design processes that we had already learned through our curriculum as well as researching concepts that were previously foreign to us, namely the dynamic application of loads and the effects of fatigue stresses.

A story was established based on the source material: the TRON movies produced by Walt Disney Studios. Thematic elements from the story were used as the basis for design implications that would become …


Design And Control Of A Bidirectional Dual Active Bridge Dc-Dc Converter To Interface Solar, Battery Storage, And Grid-Tied Inverters, Kenny George Dec 2015

Design And Control Of A Bidirectional Dual Active Bridge Dc-Dc Converter To Interface Solar, Battery Storage, And Grid-Tied Inverters, Kenny George

Electrical Engineering Undergraduate Honors Theses

In order to further reduce the size of today’s power converters, wide bandgap semiconductor technologies are being explored. These devices, such as silicon carbide (SiC), have been shown to outperform their silicon counterparts when used in high frequency switching, high temperature, and high voltage applications. These properties make them highly desirable in the bidirectional dual active bridge power converter. Being an isolated converter topology, the dual active bridge employs a transformer to provide step-up/step-down functionality and galvanic isolation for the converter. Transformers, as well as other passive components such as inductors and capacitors may be reduced in size when higher …


Microcontroller Application For Linear And Rotational Motion Sensing, Zachary Mintzer Dec 2015

Microcontroller Application For Linear And Rotational Motion Sensing, Zachary Mintzer

Computer Engineering

No abstract provided.


High Temperature Hepa Filter Test Unit Upgrades, Alexander Krippner, Ian Corcorran, Michael Burlando Dec 2015

High Temperature Hepa Filter Test Unit Upgrades, Alexander Krippner, Ian Corcorran, Michael Burlando

Mechanical Engineering

No abstract provided.


High Speed Jet Turbine Test Final Report, Kenneth Enstrom, Cameron Naugle, Isaac Thomas, Cody Lee Dec 2015

High Speed Jet Turbine Test Final Report, Kenneth Enstrom, Cameron Naugle, Isaac Thomas, Cody Lee

Mechanical Engineering

At high flight altitudes and speeds, external airplane elements are subject to immense loads. External devices must be put through testing that simulates these loads to ensure safety of the device. Our system will subject a device in need of testing to a jet of air, similar to wind seen on the surface of an airplane. The High Speed Air Jet Turbine Test project team has been tasked to design, build, and test an apparatus capable of acquiring real world flight data for micro-ram air turbines (microRAT). The micro-RAT is a device that provides power to an electrical device by …


Fuel Consumption Models For Tractors With Partial Drawbar Loads, Bryan Jeffrey Smith Dec 2015

Fuel Consumption Models For Tractors With Partial Drawbar Loads, Bryan Jeffrey Smith

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Three models for predicting fuel consumption for agricultural tractors with partial drawbar loads were compared. Data were collected from eight John Deere tractors, JD 7230R (e23), 7250R (e23), 7270R (e23), 7290R (e23), 7290R (IVT), 8320R (16 speed), 8345RT (IVT), 8370R (IVT). The tractors were tested with 7 load levels per speed at four different travel speeds as close as possible to 4, 7.5, 10, and 13 km·h-1. The IVT tractors were operated in Auto mode and the geared tractors were shifted up three gears and throttled back to the same travel speeds as the IVT tractors. The 7 …


Hybrid Aryl-Ether-Ketone And Hyperbranched Epoxy Networks, John Misasi Dec 2015

Hybrid Aryl-Ether-Ketone And Hyperbranched Epoxy Networks, John Misasi

Dissertations

In this dissertation, relationships between chemical structures, cure kinetics and network architectures are correlated to bulk mechanical properties for novel, hybrid epoxy-amine networks. The work is split into two primary sections: the first is the synthesis and characterization of multifunctional glassy networks based on aryl-ether-ketone diamine curatives, while the second is based on the synthesis and characterization of hyperbranched epoxy polymers and their resulting networks.

Three aryl-ether-ketone (AEK) diamines of increasing molecular weights were synthesized and used to cure 4,4’-tetraglycidylether of diaminodiphenylmethane (TGDDM); the resulting networks were compared to 4,4’-diaminodiphenyl sulfone cured TGDDM. Architectural differences were created by varying cure …


The Impact Of Crystal Morphology On The Thermal Responses Of Ultrasonically-Excited Energetic Materials, J. K. Miller, J. O. Mares, I. E. Gunduz, Steven F. Son, Jeff Rhoads Dec 2015

The Impact Of Crystal Morphology On The Thermal Responses Of Ultrasonically-Excited Energetic Materials, J. K. Miller, J. O. Mares, I. E. Gunduz, Steven F. Son, Jeff Rhoads

Purdue Energetics Research Center Articles

The ability to detect explosive materials may be significantly enhanced with local increases in vapor pressure caused by an elevation of the materials'temperature. Recently, ultrasonic excitation has been shown to generate heat within plastic-bonded energetic materials. To investigate the impact of crystal morphology on this heating, samples of elastic binder are implanted with single ammonium perchlorate crystals of two distinct shape groups. Contact piezoelectric transducers are then used to excite the samples at ultrasonicfrequencies. The thermal responses of the crystals are recorded using infrared thermography, and the rate of heating is estimated. Surface temperature increases up to 15 °C …


Concise Handbook For Temporary Traffic Control, Indiana Ltap, Ohio Department Of Transportation Dec 2015

Concise Handbook For Temporary Traffic Control, Indiana Ltap, Ohio Department Of Transportation

Indiana Local Technical Assistance Program (LTAP) Publications

This handbook gives the basic principles and provides examples for the design, application, installation, and maintenance of the various types of traffic control devices used in temporary traffic control or for incident management. Traffic control in roundabouts has been included in this version. The guidelines presented are in accordance with the standards provided within the Indiana Manual for Uniform Traffic Control Devices (IMUTCD). This handbook is based upon one created by the Ohio Department of Transportation, Guidelines for Traffic Control in Work Zones. Indiana LTAP expresses thanks to ODOT for their permission to reprint this material.


Stormwater Drainage Manual 2015, Christopher B. Burke, Thomas T. Burke Dec 2015

Stormwater Drainage Manual 2015, Christopher B. Burke, Thomas T. Burke

Indiana Local Technical Assistance Program (LTAP) Publications

This manual is a comprehensive catalog of procedures, design methods and criteria, and general background information which will enable the designer to quickly learn or review the basic principles of storm drainage design. Subjects included are precipitation and hydrological cycle, runoff and its estimation, open channels, flow in gutters and inlets, stormwater storage, storm sewer system design, computer applications for computing watershed runoff, and water quality. Included in the appendices are basics of statistical analysis, fundamentals of hydraulics, and a list of regulatory agencies and governmental bodies which may have jurisdiction over drainage projects. A chapter on green infrastructure has …


Investigation Into Mechanisms And Mitigation Of Alkali-Silica Reaction In Sustainable Portland Cement Concrete Containing Recycled Glass Materials, Kaveh Afshinnia Dec 2015

Investigation Into Mechanisms And Mitigation Of Alkali-Silica Reaction In Sustainable Portland Cement Concrete Containing Recycled Glass Materials, Kaveh Afshinnia

All Dissertations

A significant portion of recycled glass from municipal waste streams is not found to be suitable for reuse as cullet in the production of new glass containers, and as a result it is disposed in landfills. One of the appropriate ways to reduce the disposal of waste glass in landfills is by using it in portland cement concrete as an aggregate material and/or supplementary cementitious material to replace portion of portland cement. The high silica content of the soda glass (approximately 70%) can potentially behave as a pozzolanic material when finely ground, which may enhance the mechanical and durability properties …


Stochastic Simulation Of Lagrangian Particle Transport In Turbulent Flows, Guangyuan Sun Dec 2015

Stochastic Simulation Of Lagrangian Particle Transport In Turbulent Flows, Guangyuan Sun

Theses and Dissertations

This dissertation presents the development and validation of the One Dimensional Turbulence (ODT) multiphase model in the Lagrangian reference frame. ODT is a stochastic model that captures the full range of length and time scales and provides statistical information on fine-scale turbulent-particle mixing and transport at low computational cost. The flow evolution is governed by a deterministic solution of the viscous processes and a stochastic representation of advection through stochastic domain mapping processes. The three algorithms for Lagrangian particle transport are presented within the context of the ODT approach. The Type-I and -C models consider the particle-eddy interaction as instantaneous …


Contribution To T He Onboard Context Sensitive Information System ( Of Commercial Aircraft, Wei Tan Dec 2015

Contribution To T He Onboard Context Sensitive Information System ( Of Commercial Aircraft, Wei Tan

Theses and Dissertations

Pilots currently use paper-based documentation and electronic systems (e.g., Electronic Centralized Aircraft Monitor (ECAM) for Airbus, and Engine Indication and Crew Alerting System (EICAS) for Boeing) to help them perform procedures to ensure safety, efficiency and comfort on commercial aircrafts. Management of interconnections among paper-based operational documents can be a challenge for pilots, especially when time pressure is high in normal, abnormal, and emergency situations. This dissertation is a contribution to the design of an Onboard Context-Sensitive Information System (OCSIS). The claim is that the use of contextual information facilitates access to appropriate operational content at the right time either …


Exposure To Predator Kairomones Influences Egg Number And Size In Littorina Littorea, Jessica Raynor, Simon Rundle Dec 2015

Exposure To Predator Kairomones Influences Egg Number And Size In Littorina Littorea, Jessica Raynor, Simon Rundle

The Plymouth Student Scientist

Predator kairomones play an important role in intertidal ecosystems, but knowledge on their potential role in influencing maternal effects is lacking. The aim of this study was to test whether egg production by female Littorina littorea was influenced by short-term exposure to predator kairomones before egg laying. Laboratory populations were exposed to predator cues from the intertidal crab Carcinus maenas for nine days, and egg number, egg size, and survivorship of the offspring were measured and compared with those from reference populations. Snails exposed to predator cues produced significantly more eggs, which were also significantly smaller than those produced from …