Engineering Commons^™

Local Writing Of Exchange Biased Domains In A Heterostructure Of Co/Pd Pinned By Magnetoelectric Chromia, Uday Singh, William Echtenkamp, M. Street, Christian Binek, Shireen Adenwalla

Shireen Adenwalla Papers

The writing of micrometer-scaled exchange bias domains by local, laser heating of a thin-film heterostructure consisting of a perpendicular anisotropic ferromagnetic Co/Pd multilayer and a (0001) oriented film of the magnetoelectric antiferromagnet Cr₂O₃ (chromia) is reported. Exchange coupling between chromia’s boundary magnetization and the ferromagnet leads to perpendicular exchange bias. Focused scanning magneto-optical Kerr measurements are used to measure local hysteresis loops and create a map of the exchange bias distribution as a function of the local boundary magnetization imprinted in the antiferromagnetic pinning layer on field cooling. The robust boundary magnetization of the Cr₂O …

Evaluation Of The Impact Of Slab Foundation Heat Transfer On Heating And Cooling In Florida, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

The U.S. Department of Energy's Building America Partnership for Improved Residential Construction (BA-PIRC) performed experiments in the Florida Solar Energy Center's Flexible Residential Test Facility intended to assess for the first time (1) how slab-on-grade construction influences interior cooling in a cooling-dominated climate and (2) how the difference in a carpeted versus uncarpeted building might influence heating and cooling energy use.

Final Report: Cooling Seasonal Energy And Peak Demand Impacts Of Improved Duct Insulation On Fixed-Capacity (Seer 13) And Variable-Capacity (Seer 22) Heat Pumps, Florida Solar Energy Center, Charles Withers, Jr.

FSEC Energy Research Center®

Previous phase 1, 2, and 3 research identified that duct conductive losses to an attic environment imposed greater relative energy losses for the variable-capacity systems compared to the fixed-capacity systems (Cummings and Withers 2011) because of the longer dwell time of conditioned air in the ducts. The purpose of the Phase 4 experiments reported here was to see if duct R-value enhancement would benefit the overall operating efficiency of the variable-capacity system relatively more than the fixed-capacity system. The current Phase 4 experiments (the primary focus of this report) found that this was a secondary effect.

Imaging Right Ventricular Function To Predict Outcome In Pulmonary Arterial Hypertension, Alessandro Bellofiore, Melanie Brewis, Rebecca Vanderpool, Naomi Chesler, Martin Johnson, Robert Naeije, Andrew Peacock

Faculty Publications

Right ventricular (RV) function is a major determinant of outcome in pulmonary arterial hypertension (PAH). However, uncertainty persists about the optimal method of evaluation.MethodsWe measured RV end-systolic and end-diastolic volumes (ESV and EDV) using cardiac magnetic resonance imaging and RV pressures during right heart catheterization in 140 incident PAH patients and 22 controls. A maximum RV pressure (Pmax) was calculated from the nonlinear extrapolations of early and late systolic portions of the RV pressure curve. The gold standard measure of RV function adaptation to afterload, or RV–arterial coupling (Ees/Ea) was estimated by the stroke volume (SV)/ESV ratio (volume method) or …

The Economic Boom, Bust And Transport Inequity In Suburban Dublin, Ireland, Sarah Rock, Aoife Ahern, Brian Caulfield

Articles

This paper examines the existence and extent of transport inequity and disadvantage in new suburbs in Dublin, built during the Celtic Tiger period and as experienced during the recession. Findings are presented from a household postal survey from three case study areas built between 2001 and 2008. The case study areas are typical 'middle class' suburbs, and were constructed at a time when Ireland was experiencing unprecedented economic growth. The subsequent recession left many of these areas in significant negative equity, and householders with very limited housing mobility. Results from the survey point to considerable problems that are impacting on …

Technological Assessment Of Different Solar-Biomass Systems For Hybrid Power Generation In Europe, C. M. Iftekhar Hussain, Brian Norton, Aidan Duffy

Articles

Solar Tower thermal (ST), Parabolic Trough thermal (PT), Linear Fresnel thermal (LF) and Solar PV are discussed in the context of suitability for hybridization with biomass in Europe. Technical, economical and climate data have been compared to identify the key drivers of technology selection in setting up large scale solar-biomass hybrid power plants. The sole solar-biomass hybrid power plant is currently in operation in Spain uses PT technology due to its performance characteristics, comparatively easy installation process compared to ST and relatively higher heat and optical gain than LF. The climate condition in the EU shows that the region within …

A New Tool For Wetland Management | College Of Engineering, Usu College Of Engineering

College of Engineering News

News Release – Sept. 1, 2016 – In arid Utah, marshy wetlands — with their aquatic life and migratory birds — are among the most cherished natural resources in the state.

Inspire E-News 08-09 2016, College Of Engineering And Applied Sciences

College of Engineering and Applied Sciences News

• New students travel Parkview campus with "passports" in hand
• Auto lab upgrades make it a premier teaching and research facility
• Brueshaber awarded prestigious NASA fellowship
• Sunseeker team looking forward to showcasing new solar car

Acoustic Management Of Library Fishbowls, Zachary J. Lilley

Materials Engineering

The purpose of this project is to aid the Cal Poly Robert E. Kennedy library in modifying the “fishbowl” study spaces to more effectively maintain the desirable sound that is generated within the fishbowls while avoiding the entrance and exit of excess noise to and from the fishbowls. A collaboration between the Materials Engineering Department and the Architecture Department provided the combined expertise needed to design, test, and install a prototype acoustic treatment in fishbowl 216-R in consultation with the Cal Poly Library as the voice of the customer. The fishbowl’s undesirable acoustic properties can be attributed to the hard …

On The Feasibility Of Carbon Nanotube Windings For Electrical Machines — Case Study For A Coreless Axial Flux Motor, Vandana Rallabandi, Narges Taran, Dan M. Ionel, John F. Eastham

Power and Energy Institute of Kentucky Faculty Publications

The latest developments in carbon nanotube (CNT) wires and yarns attract great interest for potential application to electromagnetic devices, such as electrical machines and transformers. The CNT material properties are largely different from copper and aluminum in terms of electrical conductivity, mass density, and thermal transfer, creating a new design paradigm for which the traditional rules and device topologies no longer apply. This paper proposes a brushless permanent magnet multidisc axial flux construction with coreless stator and special windings and minimal rotor back iron, as a suitable topology for CNT winding application. Specific analytical closed-form sizing equations, as a function …

Towards Efficient Resource Provisioning In Mapreduce, Peter Nghiem, Silvia M. Figueira

Computer Science and Engineering

The paper presents a novel approach and algorithm with mathematical formula for obtaining the exact optimal number of task resources for any workload running on HadoopMapReduce. In the era of Big Data, energy efficiency has become an important issue for the ubiquitous Hadoop MapReduce framework. However, the question of what is the optimal number of tasks required for a job to get the most efficient performance from MapReduce still has no definite answer. Our algorithm for optimal resource provisioning allows users to identify the best trade-off point between performance and energy efficiency on the runtime elbow curve …

Flexible Residential Test Facility: Impact Of Infiltration And Ventilation On Measured Cooling Season Energy And Moisture Levels (2016), Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

Originally published in January 2014, this revision of the report clarifies and corrects references to Standard 62.2 as the 2013 version (62.2-2013), and it corrects the total CFM requirement for the subject buildings under the standard. Further, two plots have been updated to distinguish between the mechanical CFM and the total CFM required for the subject buildings under Standard 62.2-2013.

A Framework For Technology Transfer Potential Assessment, Judith Estep, Tugrul U. Daim

Engineering and Technology Management Faculty Publications and Presentations

This paper is motivated by a need to move research into application, specifically in the utility industry. There are many challenges facing the industry: an aging infrastructure, a growing population, and aggressive energy efficiency targets are just a few examples. Many technologies exist or are in development but the rate at which they are being adopted is slow. Despite a clear need to apply research results to the utility industry, a cursory review of how research proposals are evaluated within the utility industry confirms that technology transfer is only peripherally addressed. In addition, there is no mechanism to quantitatively assess …

Comparative Analysis For Fuzzy Cognitive Mapping, Byung Sung Yoon, Antoine J. Jetter

Engineering and Technology Management Faculty Publications and Presentations

Fuzzy Cognitive Mapping (FCM) is a semi-quantitative system modeling technique that is used in technology management to capture, synthesize and analyze expert and stakeholder knowledge for the purpose of technology assessment, product planning, and scenario studies. The resulting FCM models are generated in interviews, focus groups, or workshops and represent complex and dynamic systems as elements (so-called concepts) and cause-and-effect relationships. Researchers often compare FCM to investigate cognitive differences between individuals or groups, identify unique perspectives on a specific topic, or track changes in knowledge (i.e. learning). Using a variety of metrics, comparison studies investigate diverse characteristics of FCMs, such …

Public Transport Accessibility Levels For Ahmedabad, India, Jay S. Shah, Bhargav Adhvaryu

Journal of Public Transportation

Public transport plays an important role in a city’s economy and its social equity. It is also instrumental in reducing automobile dependence and traffic congestion. Several factors must come together to achieve well-functioning public transport systems. One major factor is the level of accessibility offered by the public transport system. To better understand and consequentially enhance accessibility, we must be able to measure it and map it, which is the key aim of this paper.

The methodology in this study, which was originally developed by the London Borough of Hammersmith and Fulham and later adopted by Transport for London (TfL) …

Public Transport Crowding Valuation: Evidence From College Students In Guangzhou, Jianrong Liu, Huiying Wen

Journal of Public Transportation

Overcrowding has grown to be an increasingly important issue for public transit in Guangzhou, China. To capture traveler benefits of reduced crowding from improved public transport, it is necessary to identify the relevant importance of crowding to travelers. This paper analyzes the disutility of crowding in metro car and bus transit with discrete choice models. Based on the stated preference survey data from college students in Guangzhou, the results show that there is non-negligible impact of crowding on passenger travel. The relationship between the disutility of crowding and standee density is not linear; that is, the disutility increases at a …

Cross-Elasticities In Frequencies And Ridership For Urban Local Routes, Joseph Totten, David Levinson

Journal of Public Transportation

Observational data from the Minneapolis-Saint Paul region’s Metro Transit were analyzed to determine the effects of service levels on ridership levels at different intervals. The research compares changes in service levels and ridership in several service intervals and includes elasticities and cross elasticities, or the influence that these service levels have on different service intervals’ ridership. These cross-elasticities were found to have little effect during the week; however, weekend ridership was found to be influenced by rush-hour and overnight frequencies.

Effects Of Speed, Curves, And Driver Behavior On Passive Securement Systems On Large Transit Buses, Andrea Mather, Katharine Hunter-Zaworski

Journal of Public Transportation

Wheeled mobility devices that are not secured properly on large transit vehicles pose risks to all passengers. The purpose of this study was to increase the understanding of the effects of horizontal and vertical curves, speed, and driver behavior on the safety and security of people using wheeled mobility devices in rear-facing passive containment systems on large transit buses. Testing included the use of manual wheelchairs and lightweight scooters on an articulated low-floor transit bus. The project conclusions were derived from data produced by accelerometers placed on the bus as well as visual observations of wheeled mobility device movement. The …

Evaluation Of Horizontal Equity Under A Distance-Based Transit Fare Structure, Milad Bandegani, Meisam Akbarzadeh

Journal of Public Transportation

Horizontal equity requires equal distribution of investment/benefit/costs among equal members of society. In other words, a transit passenger should pay as much as he/she uses. This study evaluated the measure of fulfillment of this rule in a case study, developed a distance-based fare structure, and shows that justice is better served by switching to the proposed structure. Fare elasticity of demand and probability distribution of transit passenger trip lengths were investigated through a field survey. Although mainly used in the measurement of inequality in income or wealth, the Gini index and the recovery ratio (revenue to cost for each transit …

Modeling Transit Users Stop Choice Behavior: Do Travelers Strategize?, Mohammad Nurul Hassan, Taha Hossein Rashidi, S. Travis Waller, Neema Nassir, Mark Hickman

Journal of Public Transportation

Transit choice research focuses predominantly on mode choice and route choice, whereas very few studies on stop choice are conducted. To fill this gap, this research aimed to study transit stop choice behavior with a focus on how people strategize when making their choices. It is hypothesized that travelers treat stops differently based on various schemes (strategies); minimizing travel time, access time, and the number of transfers are the schemes considered in this study, and the effectiveness of several discrete choice model specifications was examined. The study found that path attributes and stop attributes have significant impacts on stop selection …

Technology Planning For Emerging Business Model And Regulatory Integration: The Case Of Electric Vehicle Smart Charging, Kelly Cowan, Tugrul U. Daim

Engineering and Technology Management Faculty Publications and Presentations

Smart grid has been described as the Energy Internet: Where Energy Technology meets Information Technology. The incorporation of such technology into vast existing utility infrastructures offers many advantages, including possibilities for new smart appliances, energy management systems, better integration of renewable energy, value added services, and new busiss models, both for supply-and demand-side management. This paper proposes to build upon existing roadmapping processes by considering an integrated set of factors, including policy issues, that are specifically tuned to the needs of smart grid and have not generally been considered in other types of roadmapping efforts. It will also incorporate expert …

Conversion Of Glycerol To 1,3-Propanediol Under Haloalkaline Conditions, Melanie R. Mormile, Daniel William Roush, Dwayne A. Elias, Oliver C. Sitton

Biological Sciences Faculty Research & Creative Works

A method of producing 1,3-propanediol. The method comprises fermenting a haloalkaliphilic species of Halanaerobium with a source of glycerol into 1,3-propanediol, at a pH of greater than about 10 and at a salt concentration of greater than about 5% w/v. Furthermore, with supplementation of vitamin B₁₂, the yield of 1,3-propanediol to glycerol can be increased.

From Disaster To Development: Finance Provides A Platform To Empower Technology For Resilience To Climate Change, Daniel B. Oerther

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The Sendai Framework for Disaster Risk Reduction emphasizes four principles: understanding risk; strengthening governance; investing in resilience; and building back better. Parametric insurance, offered to nations, provides a financial platform to pool and transfer risk from the regional to the global marketplace. The Caribbean Ocean Assets Sustainability faciliTy (COAST) expands upon the prior success of parametric insurance by providing a new platform to more fully link policy and technology with the aim of increasing disaster resilience. COAST focuses upon the nexus among food and nutrition security, the health of the ocean, and the occurrence of severe weather in the Caribbean …

Capture And Recycle Of Industrial Co2 Emissions Using Mircoalgae, Michael H. Wilson, Daniel T. Mohler, John G. Groppo, Thomas E. Grubbs, Stephanie Kesner, E. Molly Frazar, Aubrey Shea, Czarena L. Crofcheck, Mark Crocker

Center for Applied Energy Research Faculty and Staff Publications

A novel cyclic flow photobioreactor (PBR) for the capture and recycle of CO₂ using microalgae was designed and deployed at a coal-fired power plant (Duke Energy’s East Bend Station). The PBR was operated continuously during the period May–September 2015, during which algae productivity of typically 0.1–0.2 g/(L day) was obtained. Maximum CO₂ capture efficiency was achieved during peak sunlight hours, the largest recorded CO₂ emission reduction corresponding to a value of 81 % (using a sparge time of 5 s/min). On average, CO₂ capture efficiency during daylight hours was 44 %. The PBR at East Bend …

Rapid Generation Of 3d Microchannels Using A Multiphoton Laser System In Blended Hydrogels To Serve As Templates For Microvascular Generation, Stephanie Renée Burtch

Theses and Dissertations

Lack of scaffold microvascularization is one of the biggest problems facing graft survival and success within current tissue engineering applications. Fortunately, techniques aiming to form microchannels within three-dimensional scaffolds have shown promise in providing templates for tube-like cell formations. Unfortunately, many current patterning approaches are limited in the types of materials the technique can be applied to and lack the ability to form capillary-sized (<10 microns in diameter) networks. In this study, a multiphoton laser was used to create channels down to the micron level within an optically-clear hydrogel scaffold. Different percentages of poly (ethylene glycol) diacryate (PEGDA) and collagen were used to create different blends of hydrogels at 0%, 1%, 2%, and 3% collagen/PEGDA (w/w). Mechanical and transmittance testing were performed on all blends in order to determine which had optimal mechanical strength and optical clarity for laser subtractive printing. Swelling and degradation were measured to confirm the scaffolds served the tissue engineering requirement of eventual degradation. All gels with PEGDA incorporation showed an increase in mechanical stability and transparency when compared to pure collagen gels. Hydrogel blends showed resistance to degradation in phosphate-buffered saline, but appeared to exhibit collagen degradation in collagenase, although no statistical significance was seen. Cell viability tests within the hydrogels showed viability in cell-seeded hydrogels when compared to dead controls, although cells lacked some markers of healthy cells, such as spreading. In conclusion, results show that hydrogel blends provide a good matrix for subtractive optical micropatterning approaches, although other types of hydrogels may improve cell spreading and other cell responses.

Time-Domain Partial Element Equivalent Circuit Solver Including Non-Linear Magnetic Materials, Daniele Romano, Giulio Antonini, Albert E. Ruehli

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a novel partial element equivalent circuit formulation to handle 3-D non-linear problems. Since the displacement currents are taken into account, the proposed formulation is not restricted to low-frequency applications, although the propagation delays are neglected. The non-linear problem is solved by means of the Newton-Raphson algorithm. Special care is taken in order to analytically compute the Jacobian of the problem. Furthermore, an adaptive setting of the time step is adopted in the transient analysis allowing to maintain the size of the time step as large as possible while preserving the accuracy. Computed results for a closed magnetic …

High-Frequency Instabilities Of Stationary Crossflow Vortices In A Hypersonic Boundary Layer, Fei Li, Meelan Choudhari, Pedro Paredes-Gonzalez, Lian Duan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Hypersonic boundary layer flows over a circular cone at moderate incidence angle can support strong crossflow instability in between the windward and leeward rays on the plane of symmetry. Due to more efficient excitation of stationary crossflow vortices by surface roughness, such boundary layer flows may transition to turbulence via rapid amplification of the high-frequency secondary instabilities of finite-amplitude stationary crossflow vortices. The amplification characteristics of these secondary instabilities are investigated for crossflow vortices generated by an azimuthally periodic array of roughness elements over a 7° half-angle circular cone in a Mach 6 free stream. The analysis is based on …

Experimental And Numerical Investigations Of Dust Effects On Surface Charging In Plasma, Kevin Chou, Daoru Frank Han, Joseph J. Wang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A series of 3-D, fully kinetic particle-in-cell (PIC) simulations were performed to simulate mesothermal plasma flow self-consistently with surface charging. Simulation results of plasma charging of a conducting surface covered by a thin dust layer in a plasma of cold ions and thermal electrons are presented. The surface potentials and potentials inside the dust layer are compared with experimental results. Results show that a layer of dust over a conducting surface creates a capacitance, which drives the surface more negative with respect to the ambient plasma.

The Concentration Of Stress At The Rotator Cuff Tendon-To-Bone Attachment Site Is Conserved Across Species, F. Saadat, A. C. Deymier, Victor Birman, S. Thomopoulos, G. M. Genin

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

Materials And Techniques Used In Cranioplasty Fixation: A Review, Basel A. Khader, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Cranioplasty is the surgical repair of a deficiency or deformity of the skull. The purpose of cranioplasty is to provide protection for the brain following cranial surgery, and to offer relief to psychological disadvantages while increasing social performance. There are several materials that had been used for cranioplasty, but an ideal product has yet to be developed, hence the ongoing research into biologic and non-biologic alternatives to the existing materials. This article critiques the products currently used for cranioplasty in order to facilitate the development of new materials, which can improve patient outcomes.