Engineering Science and Materials Commons^™

Evaluation Of Nitrous Acid Sources And Sinks In Urban Outflow, Elliott T. Gall, Robert J. Griffin, Allison L. Steiner, Jack Dibb, Eric Scheuer, Longwen Gong, Andrew P. Rutter, Basak K. Cevik, Saewung Kim, Barry Lefer, James Flynn

Mechanical and Materials Engineering Faculty Publications and Presentations

Intensive air quality measurements made from June 22–25, 2011 in the outflow of the Dallas–Fort Worth (DFW) metropolitan area are used to evaluate nitrous acid (HONO) sources and sinks. A two-layer box model was developed to assess the ability of established and recently identified HONO sources and sinks to reproduce observations of HONO mixing ratios. A baseline model scenario includes sources and sinks established in the literature and is compared to scenarios including three recently identified sources: volatile organic compound-mediated conversion of nitric acid to HONO (S1), biotic emission from the ground (S2), and re-emission from a surface nitrite reservoir …

Method For Hyper-Polarizing Nuclear Spns At Arbtrary Magnetic Felds, Carlos A. Meriles, Daniela Pagliero, Abdelghani Laraoui

Department of Mechanical and Materials Engineering: Faculty Publications

A method of dynamically polarizing the nuclear spin host of nitrogen-vacancy (NV) centers in diamond is provided. The method uses optical, microwave and radio-frequency pulses to recursively transfer spin polarization from the NV electronic spin. Nitrogen nuclear spin initialization approaching 80% at room temperature is demonstrated both in ensemble and single NV centers without relying on level anti-crossings. This makes the method applicable at arbitrary magnetic fields.

The Design And Construction Of A Torque Measuring Arm For An Air Motor, Logan Dearinger

All Undergraduate Projects

There is a system efficiency lab that sits in the thermodynamics lab of the Mechanical Engineering Technologies department. To expand this lab, a torque measuring device was needed to measure the torsional force that the pump exerts on the air motor. The expansion of this lab is important to give a better understanding of how the different mechanical parts effect the efficiency of the overall system. The first step in the expansion process was the design of a suitable torque measuring device. The most efficient design was a simple one with minimal moving parts. When the air motor is energized …

The Pneumatic Leg Extension, David G. Sedano

All Undergraduate Projects

In recent years, reaching altitudes that are higher than your normal-height has evolved from pure amusement to an “in-demand” necessity out in the field. Means of achieving greater than normal height range from wooden poles to aluminum stilts. The era of ladders and other extension methods are slowly fading away. There are many designs in the market that focus on different factors to make a stilt. As other designs focus on one or two enhancements, the pneumatic leg extension’s objective is to improve all aspects of the stilt. This radical new design differs greatly from traditional stilt designs. The pneumatic …

Me-Em 2015-16 Annual Report, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering Annual Reports

Table of Contents

• Alumni: Leading with Simulation
• Education: Simulating the Future
• Faculty: Advancing Simulation
• Graduate Seminar Series
• Enrollment & Degrees
• Graduates
• Department News
• Faculty & Staff
• Alumni
• Donors
• Contracts & Grants
• Patents & Publications

Multi-Use Fireline Handtool, Bruce W. Bernard Jr

All Undergraduate Projects

A wildland firefighter is a valuable resource to protecting public lands and managing fuels. The many hand tools used by firefighters aid in their ability to complete any required tasks effectively. Several of the tools available are specially purposed for individually grubbing, scraping, or liming. A small squad of firefighters could become a more effective resource if the tools they carried could perform several of these purposes as one single tool. To improve the effectiveness of an individual on the fireline a multi-use hand tool was designed to include an axe for liming and a heavy duty scraper for grubbing …

Case Studies Of Cavity And External Wall Insulation Retrofitted Under The Irish Home Energy Saving Scheme: Technical Analysis And Occupant Perspectives, Aimee Byrne, Gerard Byrne, Garrett O'Donnell, Anthony Robinson

Articles

The residential sector represents 27% of primary energy consumption in Ireland. This paper examines the case study of the Irish government’s national grant scheme to encourage energy efficiency retrofit in private housing. That is the Home Energy Saving (HES) Scheme, later rebranded the Better Energy: Homes (BEH) Scheme. The methodology involved monitoring several homes immediately before and after retrofit alongside discussions with occupants. The examination focused on specific measures commonly introduced through the HES/BEH programme − cavity and external wall insulation. It has been found that a significant decrease in heat loss through the walls was measured in all cases. …

Cement Based Batteries And Their Potential For Use In Low Power Operations, Aimee Byrne, Niall Holmes, Brian Norton

Articles

This paper presents the development of an innovative cement-electrolyte battery for low power operations such as cathodic protection of reinforced concrete. A battery design was refined by altering different constituents and examining the open circuit voltage, resistor loaded current and lifespan. The final design consisted of a copper plate cathode, aluminium plate anode, and a cement electrolyte which included additives of carbon black, plasticiser, Alum salt and Epsom salt. A relationship between age, temperature and hydration of the cell and the current it produced was determined. It was found that sealing the battery using varnish increased the moisture retention and …

Temperature-Dependent Helium Ion-Beam Mixing In An Amorphous Sioc/Crystalline Fe Composite, Qing Su, Lloyd Price, Lin Shao, Michael Nastasi

Department of Mechanical and Materials Engineering: Faculty Publications

Temperature dependent He-irradiation-induced ion-beam mixing between amorphous silicon oxycarbide (SiOC) and crystalline Fe was examined with a transmission electron microscope (TEM) and via Rutherford backscattering spectrometry (RBS). The Fe marker layer (7.2 ± 0.8 nm) was placed in between two amorphous SiOC layers (200 nm). The amount of ion-beam mixing after 298, 473, 673, 873, and 1073 K irradiation was investigated. Both TEM and RBS results showed no ion-beam mixing between Fe and SiOC after 473 and 673 K irradiation and a very trivial amount of ion-beam mixing (~2 nm) after 298 K irradiation. At irradiation temperatures higher than 873 …

Expanded 3d Nanofiber Scaffolds: Cell Penetration, Neovascularization, And Host Response, Jiang Jiang, Zhuoran Li, Hongjun Wang, Yue Wang, Mark A. Carlson, Matthew J. Teusink, Matthew R. Macewan, Linxia Gu, Jingwei Xie

Department of Mechanical and Materials Engineering: Faculty Publications

Herein, a robust method to fabricate expanded nanofiber scaffolds with controlled size and thickness using a customized mold during the modified gas-foaming process is reported. The expansion of nanofiber membranes is also simulated using a computational fluid model. Expanded nanofiber scaffolds implanted subcutaneously in rats show cellular infiltration, whereas non-expanded scaffolds only have surface cellular attachment. Compared to unexpanded nanofiber scaffolds, more CD68+ and CD163+ cells are observed within expanded scaffolds at all tested time points post-implantation. More CCR7+ cells appear within expanded scaffolds at week 8 post-implantation. In addition, new blood vessels are present within the expanded scaffolds at …

Comparison Between Direct And Reverse Electroporation Of Cells In Situ: A Simulation Study, Leila Towhidi, Delaram Khodadadi, Nataly Maimari, Ryan M. Pedrigi, Henry Ip, Zoltan Kis, Brenda R. Kwak, Tatiana W. Petrova, Mauro Delorenzi, Rob Krams

Department of Mechanical and Materials Engineering: Faculty Publications

The discovery of the human genome has unveiled new fields of genomics, transcriptomics, and proteomics, which has produced paradigm shifts on how to study disease mechanisms, wherein a current central focus is the understanding of how gene signatures and gene networks interact within cells. These gene function studies require manipulating genes either through activation or inhibition, which can be achieved by temporarily permeabilizing the cell membrane through transfection to deliver cDNA or RNAi. An efficient transfection technique is electroporation, which applies an optimized electric pulse to permeabilize the cells of interest. When the molecules are applied on top of seeded …

Floating-Gate Transistor Photodetector With Light Absorbing Layer, Jinsong Huang, Yongbo Yuan

Department of Mechanical and Materials Engineering: Faculty Publications

A field effect transistor photodetector that can operate in room temperature includes a source electrode, a drain electrode, a channel to allow an electric current to flow between the drain and source electrodes, and a gate electrode to receive a bias voltage for controlling the current in the channel. The photodetector includes a light-absorbing material that absorbs light and traps electric charges. The light-absorbing material is configured to generate one or more charges upon absorbing light having a wavelength within a specified range and to hold the one or more charges. The one or more charges held in the light-absorbing …

Active Stiffening Of F-Actin Network Dominated By Structural Transition Of Actin Filaments Into Bundles, Shengmao Lin, Xinwei Han, Gary C.P. Tsui, David Hui, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

Molecular motor regulated active contractile force is key for cells sensing and responding to their mechanical environment, which leads to characteristic structures and functions of cells. The F-actin network demonstrates a two-order of magnitude increase in its modulus due to contractility; however, the mechanism for this active stiffening remains unclear. Two widely acknowledged hypotheses are that active stiffening of F-actin network is caused by (1) the nonlinear force-extension behavior of cross-linkers, and (2) the loading mode being switched from bending to stretching dominated regime. Direct evidence supporting either theory is lacking. Here we examined these hypotheses and showed that a …

Integration Of Flow Studies For Robust Selection Of Mechanoresponsive Genes, Nataly Maimari, Ryan M. Pedrigi, Alessandra Russo, Krysia Broda, Rob Krams

Department of Mechanical and Materials Engineering: Faculty Publications

Blood flow is an essential contributor to plaque growth, composition and initiation. It is sensed by endothelial cells, which react to blood flow by expressing >1000 genes. The sheer number of genes implies that one needs genomic techniques to unravel their response in disease. Individual genomic studies have been performed but lack sufficient power to identify subtle changes in gene expression. In this study, we investigated whether a systematic meta-analysis of available microarray studies can improve their consistency.

We identified 17 studies using microarrays, of which 6 were performed in vivo and 11 in vitro. The in vivo studies were …

Advanced Metrology And Diagnostic Loss Analytics For Crystalline Silicon Photovoltaics., Eric Schneller

Electronic Theses and Dissertations

Characterization plays a key role in developing a comprehensive understanding of the structure and performance of photovoltaic devices. High quality characterization methods enable researchers to assess material choices and processing steps, ultimately giving way to improved device performance and reduced manufacturing costs. In this work, several aspects of advanced metrology for crystalline silicon photovoltaic are investigated including in-line applications for manufacturing, off-line applications for research and development, and module/system level applications to evaluate long-term reliability. A frame work was developed to assess the cost and potential value of metrology within a manufacturing line. This framework has been published to an …

Quantification Of The Effect Of Degassing On The Microstructure, Chemistry And Estimated Strength Of Nanocrystalline Aa5083 Powder, Clara Hofmeister

Electronic Theses and Dissertations

Degassing is a critical heat treatment process in aluminum powder metallurgy, where powders are subjected to high temperature in vacuum to remove volatile gaseous species absorbed in and adsorbed on powders. For cryomilled aluminum alloy powders with nanoscale features, degassing can cause accelerated microstructural and chemical changes including removal of volatiles, grain growth, dislocation annihilation, and formation of dispersoids. These changes can significantly alter the mechanical behavior of consolidated components based on their contributions to strength. In this study, cryomilled AA5083 (0.4 wt.% Mn; 4.5 wt.% Mg; minor Si, Fe, Cu, Cr, Zn, Ti; balance Al) powders were degassed at …

Preliminary Investigation Into The Rate Of Carbonation Of Concrete Blocks Under Normal Production Yard Conditions, Aimee Byrne, Eanna Nolan

Conference papers

The release of CO2 from calcination during the manufacture of cement can be partially or fully offset by the CO2 it naturally absorbs during its lifetime. This paper reports results from a preliminary investigation into the rate of carbonation in concrete blocks stacked in a production yard over a period of 6 months. The blocks were stacked in a normal manner under natural exposure conditions. Carbonation progress was determined by splitting the blocks and spraying the freshly exposed surface with a phenolphthalein solution at intervals over the test period. It was found that the rate of the carbonation front progression …

Urea Pre-Treatment Of N2-Annealed Transition Metal Oxides For Low Cost And Efficient Counter Electrodes In Dye-Sensitized Solar Cell, Hytham Elbohy

Electronic Theses and Dissertations

Photovoltaic cells have shown great promise as an alternative to fossil fuel-based energy sources. Dye-sensitized solar cells (DSSCs) have shown potential as low-cost replacement to silicon solar cells owing to their reduced material costs and simple fabrication techniques. Platinum (Pt) was used as a catalyst in the counter electrode for DSSCs. Metal oxides have been used as an alternative material to Pt. The introduction of oxygen vacancies inside metal oxides helps to facilitate electron transport to the electrolyte to enhance the reduction process of triiodide ions. Annealing n-type metal oxides under a reducing agent gas such as hydrogen (H2) at …

Low Temperature Solution-Processed Sb:Sno2 Nanocrystals For Efficient Planar Perovskite Solar Cells, Yang Bai, Yanjun Fang, Yehao Deng, Qi Wang, Jingjing Zhao, Xiaopeng Zheng, Yang Zhang, Jinsong Huang

Department of Mechanical and Materials Engineering: Faculty Publications

Inorganic metal oxide electron-transport layers (ETLs) have the potential to yield perovskite solar cells with improved stability, but generally need high temperature to form conductive and defect-less forms, which is not compatible with the fabrication of flexible and tandem solar cells. Here, we demonstrate a facile strategy for developing efficient inorganic ETLs by doping SnO₂ nanocrystals (NCs) with a small amount of Sb using a low-temperature solution-processed method. The electrical conductivity was remarkably enhanced by Sb-doping, which increased the carrier concentration in Sb:SnO₂ NCs. Moreover, the upward shift of the Fermi level owing to doping results in improved …

Propagation Of Extensional Waves In A Piezoelectric Semiconductor Rod, C.L. Zhang, X. Y. Wang, W. Q. Chen, J. S. Yang

Department of Mechanical and Materials Engineering: Faculty Publications

We studied the propagation of extensional waves in a thin piezoelectric semiconductor rod of ZnO whose c-axis is along the axis of the rod. The macroscopic theory of piezoelectric semiconductors was used which consists of the coupled equations of piezoelectricity and the conservation of charge. The problem is nonlinear because the drift current is the product of the unknown electric field and the unknown carrier density. A perturbation procedure was used which resulted in two one-way coupled linear problems of piezoelectricity and the conservation of charge, respectively. The acoustic wave and the accompanying electric field were obtained from the equations …