Other Engineering Commons^™

Effects Of Inclusion Shapes Within Rigid Porous Materials On Acoustic Performance, Hyun Hong, Siu-Kit Lau

Durham School of Architectural Engineering and Construction: Faculty Publications

The present study investigates the influence of various shapes of inclusions having same volume embedded in a porous rigid material. Previous studies showed improvement of the broadband sound absorption with particular shapes of inclusions. However, different volumes of the inclusions have been considered; therefore, the bulk densities are not the same for comparison. The present study extends the investigations of inclusions in porous materials with same volume (or bulk density) to eliminate the influence by the change of bulk density. The effects of shape will be discussed. Finite element modeling will be used for this study. Total four different shapes: …

Effects Of Roof Pitch On Air Flow And Heating Load Of Sealed And Vented Attics For Gable-Roof Residential Buildings, Shimin Wang, Zhigang Shen

Durham School of Architectural Engineering and Construction: Faculty Publications

Pitch value is an important consideration in residential gable roof design and construction. However, how roof pitch, coupled with air flows in attic space, affects the energy performance of building attics has been barely investigated. In this paper, a 2D unsteady computational fluid dynamics (CFD) model is employed to investigate the effects of roof pitch on air flow and heating load of both sealed and vented attics for gable-roof residential buildings. The simulation results show that air flow in the sealed attics is steady and asymmetric, while that in the vented attics is a combination of an essentially symmetric base …

Economic Modeling & Optimization Of A Region Specific Multi-Feedstock Biorefinery Supply Chain, William H. Faulkner

Theses and Dissertations--Manufacturing Systems Engineering

The objective of this thesis is to include strategic and tactical level decisions into the biorefinery supply chain design for a specific region while comparing multiple conversion technologies and biomass feedstocks. The allocation of biomass feedstocks, products, and the respective supply chain configuration locations are determined while ensuring the regions monthly biomass availability and product market demand constraints are met. This research considers all actions required to bring the bio-based products to market from harvesting, storing, and processing the biomass to market distribution. Two different conversion technologies are chosen for comparison: one advanced conversion technology and one conventional technology. Potential …

A Directionally Tunable But Frequency-Invariant Beamformer On An Acoustic Velocity-Sensor Triad To Enhance Speech Perception, Yue Ivan Wu, Kainam Thomas Wong, Xin Yuan, Siu-Kit Lau, Shiu-Keung Tang

Durham School of Architectural Engineering and Construction: Faculty Publications

Herein investigated are computationally simple microphone-array beamformers that are independent of the frequency-spectra of all signals, all interference, and all noises. These beamformers allow the listener to tune the desired azimuth-elevation “look direction.” No prior information is needed of the interference. These beamformers deploy a physically compact triad of three collocated but orthogonally oriented velocity sensors. These proposed schemes’ efficacy is verified by a jury test, using simulated data constructed with Mandarin Chinese (a.k.a. Putonghua) speech samples. For example, a desired speech signal, originally at a very adverse signal-to-interference-and-noise power ratio (SINR) of -30 dB, may be processed to become …

Teaching Sustainable Design Using Bim And Project-Based Energy Simulations, Zhigang Shen, Wayne Jensen, Tim Wentz, Bruce Fischer

Durham School of Architectural Engineering and Construction: Faculty Publications

The cross-disciplinary nature of energy-efficient building design has created many challenges for architecture, engineering and construction instructors. One of the technical challenges in teaching sustainable building design is enabling students to quantitatively understand how different building designs affect a building’s energy performance. Concept based instructional methods fall short in evaluating the impact of different design choices on a buildings’ energy consumption. Building Information Modeling (BIM) with energy performance software provides a feasible tool to evaluate building design parameters. One notable advantage of this tool is its ability to couple 3D visualization of the structure with energy performance analysis without requiring …

Creating A State-Wide Transfer Program For Engineering Technology And Technology Management Studies, Gregory Arbuckle, Mark Doggett

SEAS Faculty Publications

The primary purpose of the Western Kentucky Pipeline for 2+2+2 Engineering Technology and Technology Management (ET/TM) students program is to significantly increase degree production and workforce preparation in central and western Kentucky through the construction of a long-term sustainable, reproducible model bridging program of cooperation between Western Kentucky University (WKU), Murray State University (MSU) and the Kentucky Community and Technical College System (KCTCS). The program will significantly increase industrial and technology education opportunities, technology enrollment and two and four-year degree completion. Additionally, this project supports the Kentucky Council on Postsecondary Education’s (CPE) goal to double the overall number of undergraduate …

Perceptions And Rankings Of Technology Management Competencies, Mark Doggett, Pam Mcgee, Sophia Scott

SEAS Faculty Publications

According to Thamhain (2005) the “Management of technology is the art and science of creating value by using technology together with other resources of an organization” (p. 6). A technology manager should have some minimum level of technical knowledge, applied abilities in systems design, application, products or processes, and skills in one or more contextual areas (ITEA, 2000/2002). Technology managers must have certain competencies that are agreed-upon or measurable, preferably both. At the university level, technology management programs are distinctly different from engineering or engineering technology programs (i.e., mechanical, electrical, civil, etc.). A required management curriculum is what distinguishes ATMAE …

The Theological Origins Of Engineering, Brad Kallenberg

Theology and Religious Studies Faculty Publications

Knowledge of our roots can sometimes help us figure out how we ought to proceed. Many claim that engineering began in ancient antiquity with the Egyptian pyramids, Archimedes' inventions, or the Roman aqueducts. Others give contemporary engineering a more recent history, tracing its origins to the Industrial Revolution or the Enlightenment. Yet what is often overlooked is the fact that contemporary engineering owes part of its identity to medieval monasticism.

The advantage of remembering this history is the bearing it has on the questions "What is engineering for?" and "How ought engineering be practiced?"

Michael Davis makes the claim that, …

Fact Or Fiction?, Allison Marsh

Section 5: Imaging at the Nano Scale

No abstract provided.

Spotlight On Usc: Department Of Art, Allison Marsh

Section 5: Imaging at the Nano Scale

No abstract provided.

Usc's Nanocenter, Allison Marsh

Section 5: Imaging at the Nano Scale

No abstract provided.

Art Versus Image, Allison Marsh

Section 5: Imaging at the Nano Scale

No abstract provided.

Nano Imaging, Allison Marsh

Section 5: Imaging at the Nano Scale

No abstract provided.

What Is Nanotechnology?, Allison Marsh

Section 5: Imaging at the Nano Scale

No abstract provided.

Nanotechnology In Everyday Life, Allison Marsh

Section 5: Imaging at the Nano Scale

No abstract provided.

Choosing An Instrument, Allison Marsh

Section 5: Imaging at the Nano Scale

No abstract provided.

Impacts Of Ventilation Ratio And Vent Balance On Cooling Load And Air Flow Of Naturally Ventilated Attics, Shimin Wang, Zhigang Shen

Durham School of Architectural Engineering and Construction: Faculty Publications

The impacts of ventilation ratio and vent balance on cooling load and air flow of naturally ventilated attics are studied in this paper using an unsteady computational fluid dynamics (CFD) model. Buoyancy-driven turbulent ventilations in attics of gable-roof residential buildings are simulated for typical summer conditions. Ventilation ratios from 1/400 to 1/25 combined with both balanced and unbalanced vent configurations are investigated. The modeling results show that the air flows in the attics are steady and exhibit a general streamline pattern that is qualitatively insensitive to the variations in ventilation ratio and vent configuration. The predicted temperature fields are characterized …

The Impact Of Roof Pitch And Ceiling Insulation On Cooling Load Of Naturally-Ventilated Attics, Shimin Wang, Zhigang Shen, Linxia Gu

Durham School of Architectural Engineering and Construction: Faculty Publications

A 2D unsteady computational fluid dynamics (CFD) model is employed to simulate buoyancy-driven turbulent ventilation in attics with different pitch values and ceiling insulation levels under summer conditions. The impacts of roof pitch and ceiling insulation on the cooling load of gable-roof residential buildings are investigated based on the simulation of turbulent air flow and natural convection heat transfer in attic spaces with roof pitches from 3/12 to 18/12 combined with ceiling insulation levels from R-1.2 to R-40. The modeling results show that the air flows in the attics are steady and exhibit a general streamline pattern that is qualitatively …

Development And Evaluation Of A Simplified Modeling Approach For Hydraulic Systems, Yuebin Yu, Vivian Loftness, Daihong Yu, Yan Lu, Volker Hartkopf

Durham School of Architectural Engineering and Construction: Faculty Publications

This paper presents how a hydraulic system can be properly modeled for hydraulic balancing, knowledge of flow distribution, coupled simulation, and evaluation of control, etc. It focuses on water-based heating and cooling systems, which generally have high energy efficiency in design but could perform poorly in reality due to the undersensing condition and strong thermal-hydraulic coupling. The study introduces the motivation, presents the simplified modeling methodology, and illustrates the model and simulating structure. A preliminary evaluation of the method is conducted with two simple simulations. The proposed “node-branch-state” modeling approach could be easily modified, expanded and integrated into a detailed …

Analysis Of Wind Velocity And The Quantification Of Wind Turbulence In Rural And Urban Environments Using The Levy Index And Fractal Dimension, Jonathan Blackledge, Eugene Coyle, Niall Mccoy, Derek Kearney, Keith Sunderland, Thomas Woolmington

Articles

This paper is concerned with a quantitative and comparative analysis of wind velocities in urban and rural environments. It is undertaken to provide a route to the classification of wind energy in a rural and urban setting. This is a common problem and the basis of a significant focus of research into wind energy. In this paper, we use a non-Gaussian statistical model to undertake this task, and, through a further modification of the data analysis algorithms used, extend the model to study the effect of wind turbulence, thereby introducing a new metric for this effect that is arguably superior …

Examining The Role Of The University In Creating Jobs, Mike Murphy, Michael Dyrenfurth

Articles

This paper begins by setting out the rationale for why today’s university must be involved with job creation in terms of institutional mission and global competitiveness. We present a review of recent literature, from both sides of the Atlantic, regarding universities, technology and science parks and job creation. Measuring the impact of university actions is reviewed in terms of general criteria, impact of incubators, and where jobs are being created. A case study of Silicon Valley is reviewed as well as a discussion of roles that government might play. The paper concludes with the presentation of findings from the literature …

An Evaluation Of The Performance Of Network Rtk Gnss Services In Ireland, Audrey Martin, Eugene Mcgovern

Conference Papers

The national Geodetic infrastructure for the island of Ireland has developed rapidly to a fully GNSS compatible coordinate reference system - Irish Transverse Mercator (ITM) which is realised through a Continuously Operating Reference System (CORS) network of active GNSS stations. The National Mapping Authority’s CORS network provides data for post processing and streamed raw data for real-time network (NRTK) solutions. This NRTK raw data is currently being used by both Leica and Topcon to provide independent NRTK solutions. A second CORS network, known as VRS Now Ireland, with both RINEX and NRTK capabilities, was established in 2008 by Trimble and …

Neutrosophic Masses & Indeterminate Models Applications To Information Fusion, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

In this paper we introduce the indeterminate models in information fusion, which are due either to the existence of some indeterminate elements in the fusion space or to some indeterminate masses. The best approach for dealing with such models is the neutrosophic logic.

Electroluminescence Studies On Longwavelength Indium Arsenide Quantum Dot Microcavities Grown On Gallium Arsenide, John C. Ramsey

Theses and Dissertations

A comprehensive study of the electroluminescence of four GaAs/AlGaAs microcavity devices with InAs/GaInAs quantum dot active regions emitting near 1.3 µm was conducted. The four molecular beam epitaxial grown samples with AlAs oxide aperture confinement layers were fabricated, characterized, and optically modeled. Optical power transmission of the samples was modeled using Matlab and compared with measured transmission data. Resonant cavity light emitting diodes (RCLEDs) and three vertical cavity surface emitting laser (VCSEL) samples were fabricated and electro-optically characterized over a range of injection currents and temperatures. Devices achieved continuous wave room temperature lasing at 1.28 µm with an output power …

Validation Of Seaplane Impact Load Theory And Structural Analysis Of The Martin 270, Carrie Sell

LSU New Orleans Theses and Dissertations

Flight and drop tests of the Martin 270 (M270) seaplane were conducted in 1955. Theoretical and empirical pressures were determined by use of Wagner’s theory and also by the Code of Federal Regulations (CFR). The pressure results from the experimental tests on the hull were compared with pressures calculated from Wagner’s theory to determine how well the theory correlated with the measured pressures. The experimental pressure data was also compared with the CFR results to determine how the current industry standard of estimating impact loads compares with actual pressures a seaplane is subjected to.

Using the structural design and geometry …

Determining A Community Retrofit Strategy For The Aging Housing Stock Using Utility And Assessor Data, Nathan A. Barry

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

Residential buildings account for about 21.5% of the nation’s primary energy consumption and carbon emissions, and about 38% of electricity use. The housing stock in the United States consists of over 128 million residences with over 60% being constructed prior to 1979 when building codes and regulations began standardizing building practices. Seeking an opportunity to understand and reduce consumption, the scientific community developed a number of model-driven auditing software. While these computer models have been successful in predicting usage patterns in newer residential structures, they have been inaccurate in predicting and analyzing energy use in aging housing stock, predominantly homes …

Requirements Specification For Dsic: Distribution System For Information And Collaboration, Alex Abrahamian

Computer Science and Software Engineering

There seems to exist an invisible barrier between people that should be connected but for whatever reasons (don't hang out in the same circles, don't go to the same meetings, or are geographically separated) haven't met each other yet.

Normally these people will only meet when others bring them together or they are thrown together on a project. DSIC aims to preempt the person discovery process by allowing a way for people to post ideas, events, and other collaborations in a single place that can then be searched by other users.

The system utilizes postings, user profiles, and a tagging …

In-Situ Ellipsometry Characterization Of Anodically Grown Silicon Dioxide And Lithium Intercalation Into Silicon, Eric A. Montgomery

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

In this thesis, in-situ ellipsometry and electroanalytical investigations of two electrochemical processes are reported: including the formation of anodically grown silicon dioxide and the intercalation of lithium into silicon. Analysis of the ellipsometry data shows that the anodically grown silicon dioxide layer is uniform and has similar properties as thermally grown silicon dioxide. The lithium-ion intercalation data reveals non-uniform thin film formation, which requires further studies and development of appropriate ellipsometric optical models.

Advisers: Eva Schubert and Mathias Schubert

Time To Make Renting A Long-Term Housing Choice, Lorcan Sirr

Media

No abstract provided.

Looking After The Best Interests Of Dublin Must Be Top Priority, Lorcan Sirr, Conor Skehan

Media

No abstract provided.