Materials Science and Engineering Commons^™

Understanding Materials, Petros J. Katsioloudis

STEMPS Faculty Publications

The article discusses the importance of understanding the characteristics of materials that will be used for different applications. Through the years, the inventions and innovations in the technology of materials are becoming more technologically complex. Innovations in the materials are divided in different categories, including metals, ceramics, polymers and composites. Example of such innovations in the technology of materials include the ceramic composite applied to the surface of the space shuttle panels to absorb and release high amounts of heat.

Investigation Of The Thermoelectric Behavior Of Cu-Doped Pbteagxse, Ben Ma

All Theses

Sustainable energy research is currently on the forefront of scientific exploration thus a major effort is devoted to the development of new energy conservation and production techniques. Thermoelectric materials can play a significant part both in energy conservation and energy production via the Seebeck effect (heat to electric power) and the Peltier effect (electricity to cooling power), since they can convert wasted heat to useful electrical energy.
Presented herein are the measured electrical and thermal transport properties and phenomenal analysis of the PbTeAgxSe (x=1.9, 2.0, 2.01) system. First, it would lead to a significant reduction in the thermal conductivity and …

Giant Raman Enhancement On Nanoporous Gold Film By Conjugating With Nanoparticles For Single-Molecule Detection, Lihua Qian, Biswajit Das, Yan Li, Zhilin Yang

Electrical & Computer Engineering Faculty Research

Hot spots have the contradictively geometrical requirements for both the narrowest interstices to provide strong near-field coupling, and sufficient space to allow entrance of the analytes. Herein, a two-step method is employed to create hot spots within hybrid nanostructures, which consist of self-supported nanoporous gold films with the absorbed probes and subsequent nanoparticle conjugates without surface agents or mechanical motion. The molecules confined into 1 nm interstice exhibit 2.9 × 10⁷ times enhancement in Raman scattering compared to pure nanoporous gold. Giant enhancement primarily results from strong near-field coupling between nanopore and nanoparticle, which is theoretically confirmed by finite-difference …

Mse News 2010, Department Of Materials Science And Engineering, Michigan Technological University

Department of Materials Science and Engineering Annual Reports

Table of Contents

• MSE Welcomes New Professors
• Professor Emeritus Passes
• Alumni Achieves Milestone
• Hydrogen Storage Research
• Student Accomplishments
• Staff News
• Alumni News

Production And Characterization Of Novel Air Filtration Media, Elizabeth Skomra

All Dissertations

HEPA and ULPA filtration systems have proven to be an advantageous instrument in removing common contaminants from the air. However, an increased pressure drop due to the build-up of particulates on the filters results in its inevitable decrease in performance. Improving current filtration systems would include increasing collection efficiency all the while either maintaining or reducing the differential pressure drop in order to extend the life of the filter. One method of improving collection efficiency would be viable by increasing the amount of surface area within the filter media by glass fibers because of their inherent quality of being smaller …

Factors Controlling Ductility In Ultrafine Grain Aluminum Alloys Under Monotonic And Cyclic Loading, Partha Sarathi De

Doctoral Dissertations

"Ultrafine grained (UFG) Al processed by severe plastic deformation (SPD) methods are characterized by high strength and a limited uniform ductility. Friction stir processing (FSP), an offshoot of friction stir welding has emerged as a new technique to produce UFG alloys. FSP-UFG Al alloys show a distinctly different behavior with higher uniform elongation and improved high cycle fatigue life as compared to other SPD processed variants. The objective of this work was to study the microstructural basis for such mechanical behavior in FSP-UFG Al alloys.

To study the mechanical behavior of FSP Al alloys, a subsize bending fatigue and uniaxial …

Dependency Of Machinability In Gray Cast Iron On Nitride-Induced Age Strengthening, Jared Teague

Doctoral Dissertations

"Work of previous researchers has suggested that room temperature age strengthening in gray cast irons improves machinability. Verification and quantification of the machinability improvement is important to industry. Improved machinability will reduce overall manufacturing costs and reduce raw material consumption by decreasing the rate at which tools are replaced. Experimental work was performed to determine a connection between improved machinability in gray cast iron and changes in machining mechanics. An industrial tool wear study verified that age strengthening improved machinability by reducing tool wear to less than one-quarter of the unaged value. Laboratory tests on iron castings from the same …

Ceramic Dielectrics For High Energy Density Capacity Application, Sheng Chao

Doctoral Dissertations

"The objective of this dissertation is to investigate the relationship between the processing parameters, microstructural development, defect chemistry and electrical properties of titanium oxide (TiO₂) dielectrics for high energy density capacitor applications. The effects of aliovalent dopants on the dielectric properties of TiO₂ ceramics were investigated, aiming to further improve the desired dielectric properties especially at elevated temperatures (up to 200°C). Due to the segregation of acceptor type impurities in the starting powders, space charge polarization took place in TiO₂ ceramics with relative large grain size (>̲500nm), leading to high dielectric loss and low energy storage efficiency. Increased ratio …

Understanding Corrosion Of Ni₃(Si,Nb) Alloys In Hot Sulfuric Acid, Jen-Hsien Hsu

Doctoral Dissertations

"The Sulfur-Iodine thermochemical cycle has been proposed as a method for producing large quantities of hydrogen gas from water. However, the extreme operating environments involved limit the possible materials for construction.

Through proper heat treatment and composition control, the modified patented Ni₃(Si,Nb) alloy keeps high temperature strength to greater than 750⁰C and can be deformed by cold rolling more than 50% using multiple passes and intermediate anneals. The corrosion resistance is reproducible and maintains less than 5 mpy for a broad range of boiling sulfuric acid concentrations, including 70 wt%.

In the boiling 70 wt% sulfuric acid corrosion tests, kinetic …

Fluid Flow Related Phenomena And Inclusion Motion In Continuous Casting Strands, Yufeng Wang

Doctoral Dissertations

"To improve the efficiency of the continuous casting process and the quality of its products, this dissertation mainly investigated fluid flow related phenomena and inclusion motion in continuous casting. Mathematical simulation was performed for this purpose. Both a slab caster and a billet caster were investigated. In the study of the slab caster, the application of electromagnetic brake field on the slab mold was evaluated. The results indicated that the magnetic force decelerated the high speed steel jet, stabilized the top fluctuation, and prevented the bias flow inside the mold. The other study of this slab caster involved the fluid …

Synthesis And Characterization Of Conducting Polymer Nanostructures And Their Application In Sensors, Zhe-Fei Li

Doctoral Dissertations

"A one-step synthesis technique has been used to fabricate sensors by growing polyaniline nanofibers and polyaniline/metal nanocomposites in the active area of an interdigitated electrode array. Polyaniline nanofiber sensors can be fabricated by irradiating an aqueous precursor solution containing aniline, HCl, a metal salt, and ammonium persulfate (APS) with a high pressure Hg lamp. The sensors are ready for operation after polymerization is complete, and no additional processing steps are necessary. These sensors showed faster and more intensity response to various organic vapors than conventional bulk polyaniline sensors due to their larger surface area. A chemisorption model and a diffusion …

Effect Of Cu Addition On The Conductivity Of Xcui-(1-X)Agi,(0.1 _ X _ 0.4) Solid Solutions., Chu Lee Peng

Student Works (2010-2019)

Silver Iodide (AgI) based superionic conductors continue to be investigated for their intriguing structure phase transformation and complex but useful ion dynamics. However, unlike the others alkali iodides, AgI does not easily admit impurities in its tetrabonded zincblende structure. Introduction of copper (I) iodide (CuI) into AgI lattice was expected to initiate and stabilize changes in structure of the cation sublattice which controls the phase stability and phase transition behavior. In the present work, silver rich xCuI-(1-x)AgI (0.1 ' x ' 0.4) have been prepared by sintering method. The mixtures were ground and pelletized before subjected to sintering temperature at …

Borate Based Bioactive Glass Scaffolds For Hard And Soft Tissue Engineering, Steven B. Jung

Doctoral Dissertations

"The main objectives of this dissertation were to evaluate bioactive borate glass scaffolds for hard and soft tissue applications and determine the potential toxicity of the borate glasses on the adjacent and systemic tissues. Porous randomly oriented fiber scaffolds composed of bioactive borate glass were implanted in subcutaneous soft tissue sites and in calvaria defects of laboratory rats and no signs of toxicity (necrotic tissue, increase in macrophages or other immune cells) were detected in any of the adjacent tissues (hard or soft). Systemic organs (kidney and liver) of laboratory rats implanted with bioactive borate scaffolds were analyzed for possible …

Excitation-Induced Germanium Quantum Dot Formation On Si (100)-(2×1), Ali Oguz Er, Hani E. Elsayed-Ali

Physics Faculty Publications

The effect of nanosecond pulsed laser excitation on the self-assembly of Ge quantum dots grown by pulsed laser deposition on Si (100)-(2×1) was studied. In situ reflection high-energy electron diffraction and ex situ atomic force microscopy were used to probe the quantum dot structure and morphology. At room temperature, applying the excitation laser decreased the surface roughness of the grown Ge film. With surface electronic excitation, crystalline Ge quantum dots were formed at 250 °C, a temperature too low for their formation without excitation. At a substrate temperature of 390 °C, electronic excitation during growth was found to improve the …