Engineering Commons^™

Thermal Detection Of Biomarkers Using Phase Change Nanoparticles, Chaoming Wang

Electronic Theses and Dissertations

Most of existing techniques cannot be used to detect molecular biomarkers (i.e., protein and DNA) contained in complex body fluids due to issues such as enzyme inhibition or signal interference. This thesis describes a nanoparticle-based thermal detection method for the highly sensitive detections of multiple DNA biomarkers or proteins contained in different type of fluids such as buffer solution, cell lysate and milk by using solid-liquid phase change nanoparticles as thermal barcodes. Besides, this method has also been applied for thrombin detection by using RNA aptamer-functionalized phase change nanoparticles as thermal probes. Furthermore, using nanostructured Si surface that have higher …

Correlation Between Preparation Parameters And Properties Of Molybdenum Back Contact Layer For Cigs Thin Film Solar Cells, Eigo Takahashi

Electronic Theses and Dissertations

Molybdenum (Mo) thin film back contact layers for thin film CuIn(1-x)GaxSe2 (CIGS) solar cells were deposited onto soda lime glass substrates using a direct current (DC) planar magnetron sputtering deposition technique. Requirements for the Mo thin film as a back contact layer for CIGS solar cells are various. Sheet resistance, contact resistance to the CIGS absorber, optical reflectance, surface morphology, and adhesion to the glass substrate are the most important properties that the Mo thin film back contact layer must satisfy. Experiments were carried out under various combinations of sputtering power and working gas pressure, for it is well known …

Tunable Infrared Metamaterials, David Shelton

Electronic Theses and Dissertations

Metamaterials are engineered periodic composites that have unique refractive-index characteristics not available in natural materials. They have been demonstrated over a large portion of the electromagnetic spectrum, from visible to radiofrequency. For applications in the infrared, the structure of metamaterials is generally defined using electron-beam lithography. At these frequencies, the loss and dispersion of any metal included in the composite are of particular significance. In this regard, we investigate deviations from the Drude model due to the anomalous skin effect. For comparison with theoretical predictions, the optical properties of several different metals are measured, both at room temperature and at …

Probing The Nanoscale Interaction Forces And Elastic Properties Of Organic And Inorganic Materials Using Force-Distance (F-D) Spectroscopy, Abhilash Vincent

Electronic Theses and Dissertations

Due to their therapeutic applications such as radical scavenging, MRI contrast imaging, Photoluminescence imaging, drug delivery, etc., nanoparticles (NPs) have a significant importance in bio-nanotechnology. The reason that prevents the utilizing NPs for drug delivery in medical field is mostly due to their biocompatibility issues (incompatibility can lead to toxicity and cell death). Changes in the surface conditions of NPs often lead to NP cytotoxicity. Investigating the role of NP surface properties (surface charges and surface chemistry) on their interactions with biomolecules (Cells, protein and DNA) could enhance the current understanding of NP cytotoxicity. Hence, it is highly beneficial to …

Electro-Optic And Magneto-Dielectric Properties Of Multifunctional Nitride And Oxide Materials, Ambesh Dixit

Wayne State University Dissertations

ABSTRACT

Materials that simultaneously exhibit different physical properties provide a rich area of research leading to the development of new devices. For example, materials having a strong coupling between charge and spin degrees of freedom are essential to realizing a new class of devices referred to generally as spintronics. However, these multifunctional systems pose new scientific challenges in understanding the origin and mechanisms for cross-control of different functionalities. The core of this Ph.D. dissertation deals with multifunctional nitride and oxide compound semiconductors as well as multiferroic magnetic oxide systems by investigating structural, optical, electrical, magnetic, magnetodielectric and magnetoelectric properties.

Thin …

Investigation Of The Threshold Voltage Shift Effect Of La2o3 On Tin/Hfo2/La2o3/Sio2/Si Stacks, Ming Di

Legacy Theses & Dissertations (2009 - 2024)

The semiconductor industry continues to scale (shrink) transistor dimensions to both increase the number of transistors per integrated circuit and their speed. One important aspect of scaling is the need to decrease the equivalent oxide thickness of the transistor gate dielectric while minimizing leakage current. Traditional thin layer SiO2 or SiOxNy films have been replaced by higher dielectric constant film stacks Here we study one example, the HfO2/La2O3/SiO2 stack. This dissertation describes an investigation of the use of La2O3 to reduce the threshold voltage of TiN/HfO2/SiO2/Si stacks (high-k/metal gate stacks). A significant aspect of this study is the determination of …

Fabrication And Characterization Of Nanomaterials Grown By Electron Beam Induced Deposition Process, Juntao Li

Legacy Theses & Dissertations (2009 - 2024)

Platinum&ndash and tungsten&ndashcontaining materials were grown on bulk substrates from a variety of precursors including (CH₃)₃CH₃C₅H₄Pt, W(CO)₆, WF₆, and Pt(PF₃)₄ in either a high vacuum dual beam focused ion beam/scanning electron microscope (FIB&ndashSEM) or an environmental scanning electron microscope (ESEM). The effects of deposition conditions on the growth kinetics, microstructure and composition of the grown materials, structural and chemical homogeneity of impurities inside the deposits as well as the resistivity were investigated.

Nanoabrasives Retention And Removal Mechanisms In Polyurethane Pads For Copper Cmp, Iftikhar Ul-Hasan

Legacy Theses & Dissertations (2009 - 2024)

The continued reduction in integrated circuit (IC) feature size requires similar reductions in surface defectivity. A key source of surface defects in IC fabrication processes stems from nanoabrasives used in chemical-mechanical planarization (CMP) processing. During CMP processing, polished surfaces are more vulnerable to defects including scratching, nanoabrasive particle adhesion and nanoabrasive agglomerate adhesion. The removal of these nano-sized particles is a priority for the IC fabrication industry and is reflected in the 2008 ITRS defect budget. However, there is insufficient technical understanding regarding the retention of residual nanoabrasives on the surfaces of the CMP pad following a CMP process and …

Suppression Of Octahedral Tilts And Associated Changes In Electronic Properties At Epitaxial Oxide Heterostructure Interfaces, A. Y. Borisevich, H. Y. Chang, Mark Huijben, M. P. Oxley, S. Okamoto, Manish K. Niranjan, John D. Burton, Evgeny Y. Tsymbal, Y. H. Chu, P. Yu, R. Ramesh, Sergei V. Kalinin, S. J. Pennycook

Materials Research Science and Engineering Center: Faculty Publications

Epitaxial oxide interfaces with broken translational symmetry have emerged as a central paradigm behind the novel behaviors of oxide superlattices. Here, we use scanning transmission electron microscopy to demonstrate a direct, quantitative unit-cell-by-unit-cell mapping of lattice parameters and oxygen octahedral rotations across the BiFeO₃ -La_0:7 Sr_0:3MnO₃ interface to elucidate how the change of crystal symmetry is accommodated. Combined with low-loss electron energy loss spectroscopy imaging, we demonstrate a mesoscopic antiferrodistortive phase transition near the interface in BiFeO₃ and elucidate associated changes in electronic properties in a thin layer directly adjacent to the interface.

Experimental Study On Thermal Treatment Of Used Printed Wiring Boards (Pwbs), Xiangjun Zuo

Masters Theses

The availability of cheaper and better electronic products as a result of the rapid innovation in technology in past decades has driven the production of e-waste forward. Printed wiring board (PWB) is a component made of one or more layers of insulating material with electrical conductors. The existing processes of recycling PWBs use pyrometallurgical or hydrometallurgical methods, which generate atmospheric pollution. Green recycling has obvious benefits to decrease the amount of PWBs. Green recycling includes two features, 1) little or zero pollution of toxic gases and heavy metals, and 2) efficient (quick and economical) recycling.

The aim of this work …

Sintering And Microstructural Effects On Mechanical Properties Of Zirconium Carbide-Tungsten Cermets, Melissa M. Giles Craft

Masters Theses

"Zirconium carbide-tungsten cermets were prepared by in situ reaction sintering a mixture of zirconia and tungsten carbide. Tungsten is a refractory metal with a melting point of 3422⁰C; however, its mechanical strength decreases significantly with increasing temperature. One approach to improve the elevated temperature strength is to add ceramic particulates to the matrix. Zirconia and tungsten carbide were compacted and then reacted and sintered in a single step by heating to 2050⁰C. The resulting stoichiometric zirconium carbide-tungsten cermet had a relative density greater than 96%. Cermets with two different grain sizes were produced by altering the final sintering temperature. Sintering …

Electrochemical Characterization Of Cerium-Based Conversion Coatings On Al 7075-T6, Simon Joshi

Doctoral Dissertations

"This research used electrochemical techniques to characterize the deposition and corrosion protection behavior of cerium-based conversion coatings on AI 7075-T6. Alkaline activation decreased native oxide impedance (5.9 kΩ-cm²) by ~25% promoting deposition of 250-500 mn coatings. Activation in NaOH solutions deposited coatings with large cracks and craters, whereas Na₂C0₃ activation resulted in uniform coatings, i.e., fewer cracks and almost no craters. Uniformly deposited coatings exhibited better cathodic inhibition and higher impedance (~200 kΩ-cm²) than on NaOH activated substrates (~100 kΩ-cm²). Subsurface crevices, caused by Cl⁻ and H₂O₂ in the deposition solution, were found under large cracks and craters. Thus, Na₂CO₃ …

Characterization Of The Corrosion Protection Mechanism Of Cerium-Based Conversion Coatings On High Strength Aluminum Alloys, William R. Pinc

Doctoral Dissertations

"The aim of the work presented in this dissertation is to investigate the corrosion protection mechanism of cerium-based conversion coatings ( CeCCs) used in the corrosion protection of high strength aluminum alloys. The corrosion resistance of CeCCs involves two general mechanisms; barrier and active. The barrier protection mechanism was influenced by processing parameters, specifically surface preparation, post-treatment, and the use of gelatin. Post-treatment and the addition of gelatin to the coating solution resulted in fewer cracks and transformation of the coating to CeP0₄, which increased the corrosion resistance by improving the barrier aspect of CeCCs. CeCCs were found to best …

Phosphate Post-Treatment Of Cerium-Based Conversion Coatings On Al 2024-T3, Daimon K. Heller

Doctoral Dissertations

"Phosphate post-treatment of cerium-based conversion coatings (CeCCs) on high strength aluminum alloys can significantly improve corrosion resistance. As-deposited CeCCs exhibit corrosion pits and salt tails across the specimen surface after 3 days of exposure, but post-treated CeCCs have withstood 14 days of salt spray exposure without visibly corroding. The morphology, phase, and electrochemical properties of spray deposited CeCCs were affected by post-treatment parameters such as immersion time, solution temperature, and phosphate source. The best performing coatings were post-treated in aqueous orthophosphate solutions for at least 5 min at temperatures of at least 85⁰C. These conditions converted cerium hydroxy/peroxy species in …

Foundry Parameters For Casting High-Aluminum Lightweight Steel In Complex Shapes, Angella Marie Schulte

Masters Theses

"This work investigated the liquid metal treatment and molding practices for Fe- 30wt.%Mn-9wt.%Al-1wt.%Si-0.9wt.%C-0.5wt.%Mo steel. The goal of this research was to determine the process conditions that would produce a tough Fe-Mn-Al-C alloy and the appropriate mold design to produce a defect-free P900 plate.

Notch toughness of age-hardenable Fe-Mn-Al-C alloys decreases as phosphorus increases. Thermodynamic calculations and experimental work show that additions of Ca followed by Ce can be used to mitigate the deleterious effects of phosphorus, and the addition of Ar-stirring can be used to decrease the number of harmful aluminum nitride inclusions. In the solution-treated and aged condition (Brinell …

The Properties And Structure Of Tin Phosphate Glasses Modified With Other Oxides, Jong Wook (Austin) Lim

Masters Theses

"The main objective of this research was to evaluate the properties and structures of glasses from the stannous (SnO) phosphate system for possible use in low temperature optical applications. Glasses in the binary xSnO-(100-x)P₂O₅ system (50 ≤ x ≤ 70) were prepared and their thermal and optical properties were evaluated. Differences in glass transition temperatures (T_g) measured here and reported in the literature were explained by differences in the residual water content in the glasses, as determined by infrared spectroscopy. In general, increasing the SnO content of the binary glasses increased the refractive index and the glass transition …

Electroless Deposition Of Superconducting Magnesium Diboride Thin Films On Various Substrates, Khrupa Saagar Vijayaragavan

Wayne State University Theses

ABSTRACT

ELECTROLESS DEPOSITION OF SUPERCONDUCTING MAGNESIUM DIBORIDE THIN FILMS ON VARIOUS SUBSTRATES

by

KHRUPA SAAGAR VIJAYARAGAVAN

MAY 2010

Advisor: Dr. Susil K Putatunda

Dr. Gavin Lawes

Major: Chemical Engineering

Degree: Masters of Science

Superconducting thin films of magnesium diboride were synthesized by a novel electroless plating process. Electroless plating shares many similarities to electroplating with the major difference being the absence of a continuous bias voltage. Significantly, this work represents the first investigation where electroless deposition has been used to prepare compounds, as opposed to the elemental metals considered in all previous studies. Magnesium Diboride is a recently discovered superconducting …

Effect Of Phosphorus On Cleavage Fracture In Κ-Carbide, N. I. Medvedeva, Ryan A. Howell, David C. Van Aken, Julia E. Medvedeva

Materials Science and Engineering Faculty Research & Creative Works

To understand the origin of cleavage fracture which dominates in Fe(Mn)-Al-C alloys at a high phosphorus concentration, we performed first-principles study of the phosphorus effect on ideal cleavage energy and critical stress in κ-carbide, Fe₃ AlC, a precipitate in the austenitic alloys. We find that phosphorus has higher solubility in Fe₃ AlC than in γ-Fe and sharply reduces the cleavage characteristics of κ-carbide. We show that strong anisotropy of the Fe-P bonds in Fe₃ (Al,P) C under tensile stress, leads to the appearance of large structural voids and may facilitate crack nucleation.

An Analysis Of Strength And Ductility Of Ultrafine Grained Al Alloys, R. Kapoor, P. S. De, R. S. Mishra

Materials Science and Engineering Faculty Research & Creative Works

This paper brings together and compares data of various ultrafine grained (UFG) Al alloys processed through different routes. in general, the trend of decreasing ductility with increasing strength was observed for the UFG alloys. as compared to the coarse grained (CG) alloys, the UFG alloys show a lower ductility, a lower extent of work-hardening and a lower uniform elongation. Unlike the CG alloys, which show a large fraction of uniform to total elongation, in UFG alloys this fraction varies with processing technique. It is shown here that aging of some UFG Al alloys improves ductility. Further, it is shown that …

Influence Of Fraction Of High Angle Boundaries On The Mechanical Behavior Of An Ultrafine Grained Al-Mg Alloy, R. Kapoor, N. Kumar, R. S. Mishra, C. S. Huskamp, K. K. Sankaran

Materials Science and Engineering Faculty Research & Creative Works

The mechanical behavior of ultrafine grained AA5052 processed through different techniques-rolled, annealed, friction stir processed (FSP) and equal channel angular pressed (ECAP)-were compared and correlated with microstructure. the microstructure was characterized using electron back scattered diffraction to obtain the boundary spacing, the fraction of high angle boundaries and to estimate the dislocation density from local misorientations. Both FSP and ECAP conditions had ultrafine boundary spacing, but the fraction of high angle boundaries was larger for the FSP condition. Tensile deformation carried out at 297K, and 10-3s-1 showed a lower work-hardening rate and recovery rate for FSP as compared to the …

Friction Stir Processing Of Commercial Grade Marine Alloys To Enable Superplastic Forming, Christopher B. Smith, Arun Mohan, Rajiv S. Mishra, Murray Mahoney, Mike Miles, Scott M. Gillis, Lee M. Cerveny, Gerald Opichka

Materials Science and Engineering Faculty Research & Creative Works

The use of friction stir processing (FSP) on marine grade aluminum sheet has been investigated with the objective of locally enhancing the material properties. This can potentially allow low-cost commercial grade aluminum to be used in superplastic forming applications or further enhance the formability to allow more complex geometries to be formed. FSP has been demonstrated to enable super plasticity (uniform elongations >250%) in 5083-H116 over a range of friction stir processing conditions. © (2010) Trans Tech Publications.

Impedance Spectroscopy Of Batio₃ Cubes Suspended In Lossy Liquids As A Physical Model Of Two-Phase System, Piotr Z. Jasinski, Vladimir Petrovsky, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

Impedance spectroscopy techniques were used for analysis of the physical model in a two-phase system toward determining of dielectric constant of dielectric particles suspended in liquids at various solids loading (volume fraction) levels. Model experimental studies were conducted using BaTiO3 as a dielectric material that was prepared as small cubes of uniform size (2×2×1 mm). Barium titanate (BT) cubes having a dielectric constant of 3850 were immersed in liquids of low dielectric constant and moderate electrical conductivity. Measured impedance spectra consisted of two semicircles, which were fitted for (R∥C)(R∥C) equivalent circuit. The parameters obtained from fitting were compared with the …

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 …

Electrostatic Quadrupole Plasma Mass Spectrometer Measurements During Thin Film Depositions Using Simultaneous Matrix Assisted Pulsed Laser Evaporation And Magnetron Sputtering, Chad N. Hunter, Michael H. Check, Christopher Muratore, Andrey A. Voevodin

Chemical and Materials Engineering Faculty Publications

A hybrid plasma deposition process, combining matrix assisted pulsed laser evaporation (MAPLE) of carbon nanopearls (CNPs) with magnetron sputtering of gold was investigated for growth of composite films, where 100 nm sized CNPs were encapsulated into a gold matrix. Composition and morphology of such composite films was characterized with x-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy (TEM) analysis. Carbondeposits on a gold magnetron sputter target and carbon impurities in the gold matrices of depositedfilms were observed while codepositing from gold and frozen toluene-CNP MAPLE targets in pure argon. Electrostatic quadrupole plasma analysis was used to determine that …

Environmental Degradation Of Oxidation Resistant And Thermal Barrier Coatings For Fuel-Flexible Gas Turbine Applications, Prabhakar Mohan

Electronic Theses and Dissertations

The development of thermal barrier coatings (TBCs) has been undoubtedly the most critical advancement in materials technology for modern gas turbine engines. TBCs are widely used in gas turbine engines for both power-generation and propulsion applications. Metallic oxidation-resistant coatings (ORCs) are also widely employed as a stand-alone protective coating or bond coat for TBCs in many high-temperature applications. Among the widely studied durability issues in these high-temperature protective coatings, one critical challenge that received greater attention in recent years is their resistance to high-temperature degradation due to corrosive deposits arising from fuel impurities and CMAS (calcium-magnesium-alumino-silicate) sand deposits from air …

Morphological, Structural, And Optical Studies Of Undoped And Doped-Zno Nanostructure., Ramin Yousefi

Student Works (2010-2019)

Research concerning one-dimensional nanomaterials has grown tremendously ever since carbon nanotubes were discovered by Iijima (1991), silicon nanowires were grown by Lieber's group (1998), and ZnO nanowires and nanobelts were found by Wang's group from Georgia Tech (Pan et al., 2001). Such researches on one-dimensional structures have been one of the most important branches of science during recent decades. We can now observe the impact of these studies on the technology of one-dimensional materials and also the advanced prospect of developing new technologies. Based on this motivation, this thesis attempts to investigate some unknown properties of ZnO nanostructures as …

A Study On The Corrosion Behavior Of Nanocrystalline Nickel In Aqueous Environments, Anjana Shyam Sundar

Material Science and Engineering Theses - Archive

Nanocrystalline materials possess considerably enhanced properties arising from their small grain size. Significant interest has been paid in the past to their mechanical and physical properties. Very little attention has been attracted by their electrochemical behavior, which is expected to be affected by the significant volume fraction of grain boundaries. In the present study, corrosion experiments were conducted in nanocrystalline nickel in two entirely different solutions in order to obtain a better understanding of its corrosion behavior. This is of particular interest to MEMS and NEMS devices where electroplated nanocrystalline nickel is the metal of choice. The corrosion behavior of …

Branched And Spiral Organic Nanotubes Based On The Self-Assembly Of Bile Acids, Xuejun Zhang

Electronic Theses and Dissertations

The self-assembly of chiral amphiphilic molecules in aqueous solutions is of particular interest because the chirality of individual molecules is often expressed in their supermolecular structures. Self-assembled tubes made of chiral amphiphilic molecules represent useful supramolecular architectures which hold promise as controlled release vehicles for drug delivery, encapsulates for functional molecules, and nanoreactors for chemical reactions. Lithocholic acid (LCA) is a secondary bile acid with the concentration being identical to that of cholesterol in the hepatic bile and gallbladder. It has a rigid, nearly planar hydrophobic steroid nucleus, with four hydrogen atoms and one hydroxyl group directed toward the concave …

Structural Characterization Of Sputter-Deposited Ss304+Xal (X = 0, 4, 7 And 10 Wt.%) Coatings And Mechanically Milled Ti, Zr And, Uma Maheswara Seelam

Electronic Theses and Dissertations

Study of the metastable phases obtained by non-equilibrium processing techniques has come a long way during the past five decades. New metastable phases have often given new perspectives to the research on synthesis of novel materials systems. Metastable materials produced by two non-equilibrium processing methods were studied for this dissertation- 304-type austenitic stainless steel (SS304 or Fe-18Cr-8Ni)+aluminum coatings produced by plasma enhanced magnetron sputter-deposition (PEMS) and nanocrystalline Ti, Zr and Hf powders processed by mechanical milling (MM). The objective of the study was to understand the crystallographic and microstructural aspects of these materials. Four SS304+Al coatings with a nominal Al …

Microstructural Investigation Of Precipitation Hardened Cuni2s+Zr Alloys For Rotor Applications, Jean-Paul Vega-Garcia

Electronic Theses and Dissertations

Industrial generator components experience high stresses and electrical fields during their service life. Material integrity is key in guaranteeing component performance. CuNi2SiZr, used as rotor wedges in generators, serve to maintain rotor slot content in place while experiencing high centrifugal stresses and low cycle fatigue during start and stop at elevated temperature. The quality and integrity of this material in service can be directly related to its microstructure, which is determined by the processing procedures of the wedges. In this study, the microstructure development in this material is evaluated to eliminate grain boundary defects by optimizing processing parameters, determining the …