Engineering Commons^™

Thermal Management Using Mems Bimorph Cantilever Beams, Ronald A. Coutu Jr., Robert S. Lafleur, John P. Walton, Laverne A. Starman

Faculty Publications

This paper examines a passive cooling technique using microelectromechanical systems (MEMS) for localized thermal management of electronic devices. The prototype was designed using analytic equations, simulated using finite element methods (FEM), and fabricated using the commercial PolyMUMPs™ process. The system consisted of an electronic device simulator (EDS) and MEMS bimorph cantilever beams (MBCB) array with beams lengths of 200, 250, and 300 μm that were tested to characterize deflection and thermal behavior. The specific beam lengths were chosen to actuate in response to heating associated with the EDS (i.e. the longest beams actuated first corresponding to the hottest portion of …

Electrical Characterization Of High-K Gate Dielectrics For Advanced Cmos Gate Stacks, Yi Ming Ding

Dissertations

The oxide/substrate interface quality and the dielectric quality of metal oxide semiconductor (MOS) gate stack structures are critical to future CMOS technology. As SiO₂ was replaced by the high-k dielectric to further equivalent oxide thickness (EOT), high mobility substrates like Ge have attracted increasing in replacing Si substrate to further enhance devices performance. Precise control of the interface between high-k and the semiconductor substrate is the key of the high performance of future transistor. In this study, traditional electrical characterization methods are used on these novel MOS devices, prepared by advanced atomic layer deposition (ALD) process and with pre …

Application Of Inkjet Printing Technology To Flexible Batteries, Yuan Gu

Dissertations

Printing technologies have been considered as alternative methods to fabricate thin films in recent years. More and more functional devices like resistors, sensors, antennas and even energy storage devices have been fabricated by printing technologies. As a typical digital printing technology, inkjet printing has much more advantages over the traditional mechanical printing technologies such as: low cost, computer controllable shape design and precise deposition. In this investigation, application of inkjet printing is used to fabricate conductive tracks and rechargeable lithium ion batteries.

Particle free silver ink is developed to solve this problem. In this research, silver complex solution is printed …

Fabrication Of 3d Hydrogel-Based Microscale Tissue Analog Chip With Integrated Optofluidics, Venkatakrishnan Rengarajan

Dissertations

Lab-on-a-chip (LOC) is a device that integrates one or more laboratory functions in a single chip with dimensions ranging from a micrometer to a few millimeters. On-chip optofluidics, which combines microfluidics and tunable micro-optical components, is crucial for bio-sensing applications. However, recently reported optofluidic devices have only two-dimensional (2D) dielectric or metallic regions for sensing cellular activity, which fail to mimic the three-dimensional (3D) in vivo microenvironment of cells.

In this research, a 3D hydrogel-based micro-scale-tissue-analog-chip (µTAC) is fabricated with an integrated optofluidic design for biomedical applications. These 3D hydrogels act as a scaffold for the cellular studies and as …

15-08 Community-Aware Charging Station Network Design For Electrified Vehicles In Urban Areas: Reducing Congestion, Emissions, Improving Accessibility, And Promoting Walking, Bicycling, And Use Of Public Transportation, Ratna Babu Chinnam, Alper E. Murat

Transportation Research Center Reports

A major challenge for achieving large-scale adoption of EVs is an accessible infrastructure for the communities. The societal benefits of large-scale adoption of EVs cannot be realized without adequate deployment of publicly accessible charging stations due to mutual dependence of EV sales and public infrastructure deployment. Such infrastructure deployment also presents a number of unique opportunities for promoting livability while helping to reduce the negative side-effects of transportation (e.g., congestion, emissions, and noise pollution). In this phase, we develop a modeling framework (MF) to consider various factors and their associated uncertainties for an optimal network design for electrified vehicles. The …

Performance Prediction Of Drying Process In Residential Clothes Dryer Using Multiphysics Modeling And Simulation, Molly Shircliff

Mahurin Honors College Capstone Experience/Thesis Projects

The clothes dryer is the second highest consumer of electricity among household appliances in the U.S. However, few improvements have been made to the overall design of dryers since the 1970s. For this reason, energy efficiency research in domestic clothes dryers is a promising topic. In order to effectively and accurately research and test efficiency and design of new prototypes of the dryer, a mathematical model of the air-vented, residential dryer was created in the Energy Systems Lab at Western Kentucky University, using the text-based environment of MATLAB. This model was developed and simulated using numerical solver techniques. This model …

Biomimetic And Vascularized 3-D Liver Cancer Model, Derek Yip

Dissertations

Anti-angiogenic drugs have failed to show significant extended mortality, except when co-administered with chemotherapy drugs in clinical trials. This should be predicted by in vitro models, and yet 2D in vitro models of liver cancer co-administered with these two types of drugs show increased cell viability, contradicting clinical trials. In vitro models should mimic clinical trials in order to accurately predict drug outcomes. 2D in vitro models fail because they lack features of the cancer environment such as presence of stromal cells and a vasculature.

In order to achieve a biomimetic and vascularized in vitro model that would better recapitulate …

Processing Of Cds/Cdte Solar Cell And The Growth Model Of Cdte Thin Film, Guogen Liu

Dissertations

Cadmium telluride is the only thin film photovoltaic (PV) technology to surpass crystalline silicon PV in the cost. The most common CdTe solar cells consist of a simple p-n heterojunction structure containing a p-doped CdTe layer and n-doped cadmium sulfide (CdS) layer, which acts as a window layer. Cadmium Sulfide (CdS) thin films are often deposited on glass substrates coated with TCO layers by the close-spaced sublimation (CSS) or sputter techniques in industrial because of in-line production integration. It is seldom reported that CdS is deposited by the chemical bath deposition (CBD) batch process. The bottleneck of CBD for commercial …

Synthesis And Tribological Behavior Of Ultra High Molecular Weight Polyethylene (Uhmwpe)-Lignin Composites, Surojit Gupta, Mohammad F. Riyad, Yun Ji

Chemical Engineering Faculty Publications

In this paper, we report the synthesis and characterization of ultra-high molecular weight polyethylene (UHMWPE)-lignin composites. During this study four different compositions, namely UHMWPE, UHMWPE-13 wt. % lignin, UHMWPE-25 wt. % lignin and UHMWPE-42.5 wt. % lignin were fabricated by hot pressing. Detailed microstructural studies by scanning electron microscopy (SEM) showed that UHMWPE and UHMWPE-13 wt. % lignin had a uniform microstructure, whereas UHMWPE-25 wt. % lignin and UHMWPE-42.5 wt. % lignin samples were riddled with pores. UHMWPE and UHMWPE-13% lignin showed comparable flexural strengths of ~32.2 MPa and ~32.4 MPa, respectively. However, the flexural strength dropped drastically in UHMWPE-25 …

Economic Modelling Of The Management Of Dredged Marine Sediments, Joseph R. Harrington, Jimmy Murphy, Mary Coleman, Declan Jordan, Tristan Debuigne, Gabor Szacsuri

Publications

This paper presents and applies an economic model developed for the management of dredged marine sediments. The model predicts direct project costs and direct, indirect and induced economic impacts. The model is applied to analyse the economic aspect of the specific potential beneficial use of dredged sediment for land rec-lamation in an Irish context. The model results show the potential economic benefits to land reclamation of using dredged sediment including its value as a potential substitute for quarry based material and as an alternative to traditional offshore dredged sediment disposal, where appropriate. Analysis of other sediment management ap-proaches including wetland …

A Multimodal Investigation In Eye Movements, Raj Jaswal

Dissertations

While functional magnetic resonance imaging (fMRI) has identified which regions of interest (ROIs) are functionally active during a vergence movement (inward or outward eye rotation), task-modulated coactivation between ROIs is less understood. This study tests the following hypotheses: (1) significant task-modulated coactivation would be observed between the frontal eye fields (FEFs), the posterior parietal cortex (PPC), and the cerebellar vermis (CV); (2) significantly more functional activity and task-modulated coactivation would be observed in binocularly normal controls (BNCs) compared with convergence insufficiency (CI) subjects; and (3) after vergence training, the functional activity and task-modulated coactivation would increase in CIs compared with …

Optimization Of Headway, Stops, And Time Points Considering Stochastic Bus Arrivals, Liuhui Zhao

Dissertations

With the capability to transport a large number of passengers, public transit acts as an important role in congestion reduction and energy conservation. However, the quality of transit service, in terms of accessibility and reliability, significantly affects model choices of transit users. Unreliable service will cause extra wait time to passengers because of headway irregularity at stops, as well as extra recovery time built into schedule and additional cost to operators because of ineffective utilization of allocated resources.

This study aims to optimize service planning and improve reliability for a fixed bus route, yielding maximum operator’s profit. Three models are …

Self-Efficacy As A Long-Term Outcome Of A General Education Course On Digital Technologies, Renata A. Revelo, Christopher Schmitz, Duyen Le, Michael C. Loui

School of Engineering Education Faculty Publications

This study investigates the long-term outcomes of a general education course on digital technologies. Through cross-sectional and longitudinal interviews with students, the authors find that self-efficacy is a long-term student outcome. The primary sources of self-efficacy in the course for students were verbal persuasion and mastery experience. Faculty and teaching assistants were key sources for verbal persuasion. Some students experienced a success paradox: they felt successful in the course even though they failed to meet all of their initial expectations. This study can guide faculty in designing a course to promote student self-efficacy.

Enhancement Of Binding Characteristics For Production Of An Agglomerated Product, Darrell Neal Taulbee, Robert Hodgen

Center for Applied Energy Research Faculty Patents

A method is provided for preparing a product from a precursor material. The method includes the steps of (a) mixing a particulate material and a binder to form a precursor material and (b) irradiating that precursor material with microwave radiation so as to activate the binder and form the product.

Temporal Variations Of Water Productivity In Irrigated Corn: An Analysis Of Factors Influencing Yield And Water Use Across Central Nebraska, Tony Carr, Haishun Yang, Chittaranjan Ray

Nebraska Water Center: Faculty Publications

Water Productivity (WP) of a crop defines the relationship between the economic or physical yield of the crop and its water use. With this concept it is possible to identify disproportionate water use or water-limited yield gaps and thereby support improvements in agricultural water management. However, too often important qualitative and quantitative environmental factors are not part of aWP analysis and therefore neglect the aspect of maintaining a sustainable agricultural system. In this study, we examine both the physical and economic WP in perspective with temporally changing environmental conditions. The physical WP analysis was performed by comparing simulated maximum attainable …

Optical Patterning Of Trapped Charge In Nitrogen-Doped Diamond, Harishankar Jayakumar, Jacob Henshaw, Siddharth Dhomkar, Daniela Pagliero, Abdelghani Laraoui, Neil B. Manson, Remus Albu, Marcus W. Doherty, Carlos A. Meriles

Department of Mechanical and Materials Engineering: Faculty Publications

The nitrogen-vacancy (NV) centre in diamond is emerging as a promising platform for solid-state quantum information processing and nanoscale metrology. Of interest in these applications is the manipulation of the NV charge, which can be attained by optical excitation. Here, we use two-colour optical microscopy to investigate the dynamics of NV photo-ionization, charge diffusion and trapping in type-1b diamond. We combine fixed-point laser excitation and scanning fluorescence imaging to locally alter the concentration of negatively charged NVs, and to subsequently probe the corresponding redistribution of charge. We uncover the formation of spatial patterns of trapped charge, which we qualitatively reproduce …

Reconfigurable Liquid Attenuated Collimator, Larry W. Burggraf, Benjamin R. Kowash, Jack G. M. Fitzgerald

AFIT Patents

A reconfigurable radiographic aperture mask collimator apparatus includes a body portion configured to receive an attenuating liquid having a first attenuation value per unit volume. The apparatus further includes a grid portion mated to a face of the body portion and a plurality of passageways each having a cross sectional area and a length. The plurality of passageways is disposed within the grid portion. A plurality of plugs is slidably disposed within the plurality of passageways, and each of the plurality of plugs has a second attenuation value per unit volume less than the first attenuation value. One of the …

An Engineering Approach To Industrial Research And Development Of Pillows, Wesley Patterson

Mahurin Honors College Capstone Experience/Thesis Projects

Comfort during sleep, though taken for granted, involves a great amount of research and engineering. Few give it a second thought, but nearly one-third of a person’s life is spent with their head on a pillow, thus making them a point for increased quality. Having been approached by a tier-1 bedding manufacturer, a team of both mechanical and electrical engineers was been tasked with the goal of creating a valid research tool that the customer, Tempur-Sealy, will utilize in the company’s research and development of high-end pillows. The team sought to tackle this project utilizing tools and knowledge gained throughout …

Study On Some Issues About Safety Assurance And Maintenance Of China's Maritime Search And Rescue Helicopter, Zhenhua Xiang

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

Risk Assessment And Control Of Passenger Transportation On Water In Shanghai Port Area, Lei Peng

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

Vessel Navigation Safety Analysis And Countermeasures In The Water Of Taizhou Yangtze River Bridge, Guojin Han

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

Improvement Of Wrecks Removal Mechanism In Inland Waters Of China : A Case Study On The Yangtze River, Chichao Jiang

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

Risk Assessment In Narrow Chanel, Xiaoyang Gao

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

Study On Open-Packing Inspection Of Dangerous Goods Container At Shanghai Port, Guohua Li

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

Research On Navigation Guarantee Measures Of Modified Dan’Gan Waterway Routeing System, Peng Chang

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

Research On Safety Evaluation Of Navigation Environment In Hangzhou Bay Bridge, Ning An

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

Study On The Efficacy Of Helicopters In The Field Of Maritime Rescue, Qi Zhu

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

Environmental Damage Risk Assessment And Emergency Scheme Of Ship Oil Spill Around Xiamen Sea, Congchao Zhang

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

The Oil Spill Risk Assessment And Research On The Oil Pollution Emergency Plan In Cnooc(Huizhou) Logistics Base Wharf, Hui Yi

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

Risk Assessment On Oil Spill In Dalian Port Sea Area, Yang Wu

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.