Engineering Commons^™

Test 2014a: Case Ih Farmall 75a, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

More Carrot Than Stick: Encouraging Computer Programming In Thermal Design Projects, Kevin D. Cole

Department of Mechanical and Materials Engineering: Faculty Publications

Students will do almost anything to avoid using thermal-property tables. In this paper, Matlab-based thermal-property software is described as an enticement for students to do computer programming in the design of thermal systems. Downloaded shareware was used for steam properties in a steam-cycle project, and an air-property package was developed for use with a gas-turbine project. Although the use of computer programming required considerable effort by both instructor and students, most students did gain a better appreciation of the utility of writing computer programs as part of engineering design. Student evaluations of the course were not significantly affected compared to …

Role Of Helmet In The Mechanics Of Shock Wave Propagation Under Blast Loading Conditions, Shailesh G. Ganpule, Linxia Gu, Aaron L. Alai, Namas Chandra

Department of Mechanical and Materials Engineering: Faculty Publications

The effectiveness of helmets in extenuating the primary shock waves generated by the explosions of improvised explosive devices is not clearly understood. In this work, the role of helmet on the overpressurization and impulse experienced by the head were examined. The shock wave–head interactions were studied under three different cases: (i) unprotected head, (ii) head with helmet but with varying head–helmet gaps and (iii) head covered with helmet and tightly fitting foam pads. The intensification effect was discussed by examining the shock wave flow pattern and verified with experiments. A helmet with a better protection against shock wave is suggested.

Effects Of Mass Layer Nonuniformity On A Quartz-Crystal Microbalance, Nan Liu, Jiashi Yang, Weiqiu Chen

Department of Mechanical and Materials Engineering: Faculty Publications

We study the effects of the nonuniform thickness of a thin mass layer on a quartz-crystal microbalance. A theoretical analysis is performed on thickness-shear (TSh) vibration of an AT-cut quartz plate with a nonuniform mass layer. Mindlin’s 2-D equation for TSh vibration of a quartz plate is used. An elliptical mass layer with stepped thickness is considered which allows an exact analysis based on the plate equation. Free vibration frequencies and modes are obtained. The effects of the mass layer nonuniformity are examined. Results show that a mass layer thicker at the center tends to confine more modes under the …

Intermediate Layers In Tandem Organic Solar Cells, Yongbo Yuan, Jinsong Huang, Gang Li

Department of Mechanical and Materials Engineering: Faculty Publications

Tandem structures can boost the efficiency of organic solar cell to more than 15%, compared to the 10% limit of single layer bulk heterojunction devices. Design and fabricating of intermediate layers plays a very important role to achieve high device performance. This article will review the main experimental progresses of tandem organic solar cells, and focus on the intermediate layers (charge recombination layers) in both thermal evaporated and solution processed organic tandem solar cell devices.

A Model Of Giant Vacuole Dynamics In Human Schlemm’S Canal Endothelial Cells, Ryan M. Pedrigi, David Simon, Ashley Reed, W. Daniel Stamer, Darryl R. Overby

Department of Mechanical and Materials Engineering: Faculty Publications

Aqueous humour transport across the inner wall endothelium of Schlemm’s canal likely involves flow through giant vacuoles and pores, but the mechanics of how these structures form and how they influence the regulation of intraocular pressure (IOP) are not well understood. In this study, we developed an in vitro model of giant vacuole formation in human Schlemm’s canal endothelial cells (HSCECs) perfused in the basal-to-apical direction (i.e., the direction that flow crosses the inner wall in vivo) under controlled pressure drops (2 or 6 mmHg). The system was mounted on a confocal microscope for time-lapse en face imaging, and cells …

Trust-Based Techniques For Collective Intelligence In Social Search Systems., Pierpaola Dondio, Luca Longo

Books/Book Chapters

A key-issue for the effectiveness of collaborative decision support systems is the problem of the trustworthiness of the entities involved in the process. Trust has been always used by humans as a form of collective intelligence to support effective decision making process. Computational trust models are becoming now a popular technique across many applications such as cloud computing, p2p networks, wikis, e-commerce sites, social network. The chapter provides an overview of the current landscape of computational models of trust and reputation, and it presents an experimental study case in the domain of social search, where we show how trust techniques …

An Integrated Decision Support Framework For Remanufacturing In The Automotive Industry, Akhilesh Kumar

Wayne State University Dissertations

In today's global economy, firms are seeking any and every opportunity to differentiate from competitors by reducing supply chain costs and adding value to end customers. One increasingly popular option, under growing consumer awareness and increasing legislation, is to reintegrate returned products into the supply chain to achieve economic benefits as well as improve sustainability. An important class of such "reverse" goods flows has to do with remanufacturing (reman), which refers to activities that restore returned products ("cores") or their major modules to operational condition for using in place of new product or distributing through other channels (e.g., spare parts). …

Robust Decentralized Formation Flight Control, Weihua Zhao, Tiauw Hiong Go

Aerospace, Physics, and Space Science Faculty Publications

Motivated by the idea of multiplexed model predictive control (MMPC), this paper introduces a new framework for unmanned aerial vehicles (UAVs) formation flight and coordination. Formulated using MMPC approach, the whole centralized formation flight system is considered as a linear periodic system with control inputs of each UAV subsystem as its periodic inputs. Divided into decentralized subsystems, the whole formation flight system is guaranteed stable if proper terminal cost and terminal constraints are added to each decentralized MPC formulation of the UAV subsystem. The decentralized robust MPC formulation for each UAV subsystem with bounded input disturbances and model uncertainties is …

Staggered Truss Frames, Jordan Piaskowsky, Owen Prough

Symposium on Research and Creative Expression (SORCE)

Staggered truss framing systems have been gaining popularity for use in structural engineering because they provide large, column-free openings and rapid construction. However, their performance during seismic events has not been fully investigated. The failure of the shear connection between the floor system and the top of the truss may cause building failure and is essential to the understanding of the behavior of staggered trusses during an earthquake. The shear connection will be tested by simulating a seismic event. The strong wall/floor at Valparaiso University will be utilized to test a scale model of the shear connection until failure. The …

Solar Furnace: Heliostat And Concentrator Design, Tyler Heagney, Andrew Schiller, Matthew Gaide

Symposium on Research and Creative Expression (SORCE)

In recent decades, solar energy has been shown as a viable, clean, and abundant alternative to fossil fuels. Many methods of solar energy collection are being researched, with solar thermal electrochemistry being one of the most promising. Solar thermal electrochemistry uses sunlight to heat a furnace to temperatures nearing 2000 K. At these temperatures, metallic oxides can be decomposed to metals and oxygen with minimal electrical work. Achieving these high temperatures requires a solar furnace that consists of a heliostat to track and reflect the sun’s rays into a concentrator, which then focuses the sunlight to a single point in …

Oxidation Performance Of Ultra-High Temperature Ceramics In Air And A Simulated Combustion Environment, Tim Englert

Symposium on Research and Creative Expression (SORCE)

The oxidation resistance of various (Zr or Hf)B2-based ceramics will be tested in order to evaluate their respective performances in both furnace and oxyacetylene torch environments. Furnace testing will allow experimentation at temperatures similar to hypersonic travel or reentry conditions (>2000°C); use of an oxyacetylene torch flame will enable the replication of severe thermal gradients and combustion conditions. Oxidation resistance will be firstly quantified by measuring a sample’s change in mass after exposure to the testing environment for a defined time period. A sample that experiences a smaller change in mass is better able to resist oxidation. Oxidation rate …

Solar Thermal Electrolytic Production Of Mg From Mgo, William Sheline, L. Matthews, N. Lindenke, S. Duncan, R. Palumbo

Symposium on Research and Creative Expression (SORCE)

The electrolytic production of Mg from MgO was experimentally and theoretically investigated near 1550 K. The oxide was dissolved in either CaF2 or MgF2. The cathode was Mo and the anode was either Pt or Cgr. Mg evolved as a gas, was quenched on cooling coils at the exit of the reactor and was collected for analysis. A thermodynamic cycle study indicates that the ideal thermal efficiency for the solar process is 35 percent for an inert anode and 39 percent for a carbon anode, making the process competitive with the industrial potential of other solar to metal processes. Experimental …

Decoupled Solar Thermal Chemical Electrolysis Of Water To Produce Hydrogen, Melissa Meyer, Megan Wilken

Symposium on Research and Creative Expression (SORCE)

Solar thermal chemical research at Valparaiso University focuses on using concentrated solar energy to produce hydrogen, which can be used to generate electricity in fuel cells. A two-step solar electrolytic process has been proposed for chemical systems such as Fe2O3/Fe3O4, Co3O4/CoO, and Mn2O3/MnO. This new process produces hydrogen using ideally 63-82% less electricity than the traditional electrolytic process. Theoretical solar-to-electrical efficiencies are approximately 19-40%, a range comparable to similar solar thermal chemical processes. Preliminary experimental work with the Fe2O3/Fe3O4 system has validated the chemical possibility of each step of the process. Future work seeks to determine if the proposed processes …

Oxidation Performance Of Ultra-High Temperature Ceramics In Air And A Simulated Combustion Environment, Kevin Fedde

Symposium on Research and Creative Expression (SORCE)

The objective of this experiment is to evaluate the oxidation performance and heat resistance of the Ultra-high Temperature Ceramics (UHTCs) ZrB2 and HfB2 under high temperature, high heat flux, ablative, and oxidative environments. The investigation of UHTCs such as ZrB2 and HfB2 could potentially lead to new, easily reusable thermal protection systems (TPS) for space craft. The UHTC samples will be oxidized using an oxy-acetylene torch and a high temperature air furnace. The torch will expose the samples to rapid heating, high velocity combustion gasses, and sample temperatures in excess of 3000°C. The furnace will expose the samples to temperatures …

Experimental Analysis Of An Alternator Excited With Photovoltaic Cells For Small Power Plants, Kami̇l Ri̇fat İrfan Güney, Nevzat Onat

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, an automatic voltage regulator fed by photovoltaic (PV) cells was designed for use in small power alternators. The design aimed to increase the energy output of the alternator and to ensure necessary current output from the PV cells to support the synchronous generator excitation system. For energy transformation from small renewable energy sources, designers have favored the use of alternators that produce higher quality electric power, rather than asynchronous generators. We also address the designed system's suitability for real-life application, examining the steady-state performance of the photovoltaic cell excited alternator (PVCEA) with various loads and its behavior …

Program And Proceedings: Nebraska Academy Of Sciences 1880–2011, 131st Anniversary Year, One Hundred-Twenty-First Annual Meeting

Nebraska Academy of Sciences: Programs and Proceedings

Program

Aeronautics and Space Science

Collegiate Academy: Biology

Collegiate Academy: Chemistry and Physics

Chemistry and Physics

Biological and Medical Sciences

Junior Academy, Senior High Competition

Nebraska Wesleyan University Health and Sciences Graduate School Fair, Olin and Smith Curtiss Halls

Teaching of Science and Math

Aeronautics and Space Science, Poster Session

Applied Science and Technology

Maiben Memorial Lecture: Erin Flynn, Omaha Henry Doorly Zoo

Aeronautics

Anthropology

Earth Science

Junior Academy, Junior High Competition

Ultra-Low Power Electronics For Autonomous Micro-Sensor Applications, Rebeka Davidova

USF Tampa Graduate Theses and Dissertations

This thesis presented the research, design and fabrication associated with a unique application of rectenna technology combined with lock-in amplification. An extremely low-power harmonic transponder is conjoined with an interrogator base-station, and utilizing coherent demodulation the Remote Lock-In Amplifier (RLIA) concept is realized. Utilizing harmonic re-radiation with very low-power input, the 1^st generation transponder detects a transmitted interrogation signal and responds by retransmitting the second harmonic of the signal. The 1^st generation transponder performs this task while using no additional power besides that which accompanies the wireless signal. Demonstration of the first complete configuration provided proof of concept …

Performance Enhancement Using Cross Layer Approaches In Wireless Ad Hoc Networks, Murad Khallid

USF Tampa Graduate Theses and Dissertations

Ad hoc network is intrinsically autonomous and self-configuring network that does not require any dedicated centralized management. For specialized applications such as, military operations, search-and-rescue missions, security and surveillance, patient monitoring, hazardous material monitoring, 4G (4th Generation) coverage extension, and rural communication; ad hoc networks provide an intelligent, robust, flexible and costeffective solution for the wireless communication needs.

As in centralized wireless systems, ad hoc networks are also expected to support high data rates, low delays, and large node density in addition to many other QoS (Quality of Service) requirements. However, due to unique ad hoc network characteristics, spectrum scarcity, …

A Study On The Miniaturization Of Microstrip Square Open Loop Resonators, Luis Manuel Ledezma

USF Tampa Graduate Theses and Dissertations

A miniaturization technique that allows the size of microstrip square open loop resonators to be reduced by more than 80% is presented and studied. The technique is based on the loading of the resonator with a series surface mount capacitor. It is shown that this technique allows the design of microwave bandpass filters with a wider stopband when compared with conventional designs. It is also proved that the insertion loss of the miniaturized filter is not degraded, but in fact can be maintained or even enhanced by the miniaturization process; this is true whenever the quality factor of the lumped …

Novel Film Formation Pathways For Cu2znsnse4 For Solar Cell Applications, Sree Satya Kanth Bendapudi

USF Tampa Graduate Theses and Dissertations

Because of the anticipated high demand for Indium, ongoing growth of CIGS technology may be limited. Kesterite materials, which replace In with a Zn/Sn couple, are thought to be a solution to this issue. However, efficiencies are still below the 10% level, and these materials are proving to be complex. Even determination of the bandgap is not settled because of the occurrence of secondary phases. We use a film growth process, 2SSS, which we believe helps control the formation of secondary phases. Under the right growth conditions we find 1/1 Zn/Sn ratios and XRD signatures for Cu2ZnSnSe4 with no evidence …

Investigation Of Titanium Nitride As Catalyst Support Material And Development Of Durable Electrocatalysts For Proton Exchange Membrane Fuel Cells, Bharat Avasarala

Legacy Theses & Dissertations (2009 - 2024)

The impending energy and climatic crisis makes it imperative for human society to seek non-fossil based alternative sources for our energy needs. Although many alternative energy technologies are currently being developed, fuel cell technology provides energy solutions, which satisfy a wide range of applications. But the current fuel cell technology is far from its target of large scale commercialization mainly because of its high cost and poor durability. Considerable work has been done in reducing the cost but its durability still needs significant improvement. Of the various materials in a PEM fuel cell, the degradation of electrocatalyst affects its durability …

Effects Of Radiation-Induced Carbon Contamination On The Printing Performance Of Extreme Ultraviolet Masks, Yu-Jen Fan

Legacy Theses & Dissertations (2009 - 2024)

This dissertation investigates one of the remaining issues for extreme ultraviolet (EUV) lithography, the effects of radiation induced carbon contamination on the printing performance of patterned EUV masks. The impact of carbon contamination on EUV masks is significant due to the throughput loss and potential effects on imaging performance, and occurs when multilayer surfaces are exposed to EUV radiation with residual carbonaceous species present. Current carbon contamination research is primarily focused on the lifetime of the multilayer surfaces, determined by reflectivity loss and reduced throughput in EUV exposure tools. However, contamination on patterned EUV masks can cause additional effects on …

An Exploration Of Focused Electron Beam-Induced-Deposition At Cryogenic Temperatures, Matthew Bresin

Legacy Theses & Dissertations (2009 - 2024)

A modified version of electron beam-induced-deposition (EBID) has been studied, where cryogenic substrates were employed to alter the growth environment. Cryogenic substrates enabled multi-layer condensed phase films, which, upon electron exposure and reheating to room temperature, exhibited several unique surface morphologies not present in traditional EBID deposits. By analyzing the composition and structure of the cryogenic deposits, along with simulation of energy deposition from exposure, a diffusion based growth mechanism has been proposed. To test the validity of the proposed model, several process variables were investigated including electron flux, electron fluence, condensate thickness and precursor type. Using the knowledge garnered …

A New Method For The Removal Of Parasitic Capacitances From Sub-100nm Mosfets Using Low-Noise Split Capacitance-Voltage Measurements, Daniel R. Steinke

Legacy Theses & Dissertations (2009 - 2024)

The physical shape of MOSFETs and the processing involved in their fabrication give rise to parasitic capacitances. These capacitances are typically small compared to the intrinsic channel capacitance of the device, but as MOSFETs scale into the sub-100nm gate length range, the parasitic capacitances become a significant percentage of the overall measured capacitance, resulting in a source of error in the analysis of these devices. The purpose of this work is to describe these parasitic capacitances and their origin in MOSFET structures and to propose a method for their removal for analysis. The experimental devices used for this work are …

Effects Of Low Energy E-Beam Irradiation On Graphene And Graphene Field Effect Transistors And Raman Metrology Of Graphene On Split Gate Test Structures, Gayathri Rao

Legacy Theses & Dissertations (2009 - 2024)

Apart from its compelling performance in conventional nanoelectronic device geometries, graphene is an appropriate candidate to study certain interesting phenomenon (e.g. the Veselago lens effect) predicted on the basis of its linear electron dispersion relation. A key requirement for the observation of such phenomenon in graphene and for its use in conventional field-effect transistor (FET) devices is the need to minimize defects such as consisting of - or resulting from - adsorbates and lattice non-uniformities, and reduce deleterious substrate effects. Consequently the investigation of the origin and interaction of defects in the graphene lattice is essential to improve and tailor …

The Formation And Distribution Of Hippocampal Synapses On Patterned Neuronal Networks, Natalie Michelle Dowell-Mesfin

Legacy Theses & Dissertations (2009 - 2024)

ABSTRACT

Synthesis, Processing And Characterization Of Silicon-Based Templated Nanowires, Jae Ho Lee

Legacy Theses & Dissertations (2009 - 2024)

Semiconductor and metallic nanowires have attracted substantial attention due to their wide variety of applications, ranging from nanoelectronics to energy storage devices. In particular, self-assembled silicon nanowires (SiNWs) may be an attractive alternative to conventionally processed planar silicon since SiNWs can potentially function as both the switch (i.e. transistor) and local interconnect (e.g. metal silicide nanowire) to form an inherently integrated nanoelectronic system. Also, hierarchical (branched) nanowire systems hold potential for catalysts or porous electrode applications for energy applications

High-K Gate Stack On Compound Semiconductor Channel Materials For Low Power, High Performance Digital Logic Applications, Rama Kambhampati

Legacy Theses & Dissertations (2009 - 2024)

Group III-V compound semiconductors such as InGaAs and InGaSb are actively being considered as channel materials for low power, high performance digital logic applications due to superior carrier transport properties such as mobility and saturation velocity. The high density of interface states at high-k dielectric and III-V interface that results in pinning of Fermi level is one of the major challenges that need to be addressed before III-V CMOS becomes a mainstream technology.

Cost-Effective Imprint Template Fabrication For Step And Flash Imprint Lithography, Adam Marc Munder

Legacy Theses & Dissertations (2009 - 2024)

The College of Nanoscale Science and Engineering (CNSE) is studying imprint template fabrication with the 100kV Vistec VB300 Gaussian E-Beam writer. The major goal is to develop and advance imprint template fabrication technology using low cost quartz wafers for proof-of-concept demonstrations.