Materials Science and Engineering Commons^™

Amine-Thiol Solution Route Method For Fabricating Cdxzn1-Xs Thin Film Solar Cells, Preston D. Fernandez, Xianyi Hu, Carol Handwerker, Rakesh Agrawal

The Summer Undergraduate Research Fellowship (SURF) Symposium

Cadmium zinc sulfide, CdZnS, is a promising material for the buffer layer of thin film solar cells because the alloy is considerably more cost effective and more optimizable than pure cadmium sulfide, CdS, in terms of band gap. The current fabrication methods of the buffer layer often require expensive equipment or produce undesirable impurities in the alloy. This study investigates a cost effective and scalable solution route method to synthesize the CdZnS buffer layer. Molecular precursors of CdZnS were dissolved in varying molecular ratios of cadmium and zinc in a mixture of hexylamine and propanethiol. The resulting alloys produced were …

Radiation Tailored Polymers For Detectors, Adhesive-Coatings And Other Industrial Uses, Anna M. Earley, Alex Bakken, Rusi P. Taleyarkhan

The Summer Undergraduate Research Fellowship (SURF) Symposium

The ever growing importance of humans to depend on renewable resources has shifted the focus of consumers, producers, and even politicians to more sustainable answers. Furthermore, pressure on the oil and natural gas industry has elevated the status of biopolymers in this regard. Polylactic acid (PLA) is unique polymer that offers unique abilities for tailored property derivation; thereby, enabling one to replace many engineered polymers and provide a sustainable solution as a nontoxic renewable resource. As a bioplastic, the tailoring of PLA under various conditions is important to the application and integration into current industry uses. After irradiating high molecular …

Characterizing Hmx/Ap Cocrystal Propellant Through Planar Laser Induced Fluorescence, Seth M. Nielsen, Michael S. Powell, Steven F. Son

The Summer Undergraduate Research Fellowship (SURF) Symposium

Energetic cocrystals, or energetic materials that consist of two or more components that form a unique crystalline structure with unique properties, are currently being investigated as a possible method for decreasing the sensitivity of high energy density explosives for use in powerful solid composite propellants. Fuels more powerful than those in current use have not been practical because of their increased safety hazard due to higher sensitivity to being ignited. This has been one of the barriers that has prevented solid composite propellants from seeing significant improvements in performance. This study is an attempt to characterize a cocrystal of HMX …

Design Maps For Fracture Resistant Functionally Graded Materials, Muhammad Ridwan Murshed

Theses and Dissertations

The objective of this research is to generate design maps to identify functionally graded microstructures with enhanced fracture toughness. Several Functionally Graded Materials (FGMs) with an edge crack and membrane loading are considered and the resulting J-integral values are computed numerically using Finite Element Analysis. In order to capture the resulting stress fields accurately, Barsoum elements are used in the vicinity of the crack tip and the simulations are carried out for several crack lengths (a) and material contrasts (κ). The averages of the J-integral values are used to determine the normalized Stress Intensity Factors which are then benchmarked with …

Development Of Eco-Friendly Composite Foam Boards For Thermal Insulation And Packaging Purposes Using Cellulose Nanofibrils (Cnf), Nadir Yildirim

Electronic Theses and Dissertations

Reducing energy consumption is a high priority in the United States and throughout the world. Energy used to heat and cool occupied constructed facilities is of particular concern, and one of the most effective strategies is insulating the building envelope. Historically, builders used whatever material was available to fill the void between interior and exterior walls, including wool fibers, paper, and even corn cobs. Today, homes are built using foam insulation that harden when applied, blown-in loose insulation, fiberglass mats or rigid foam boards usually composed of polystyrene. Rigid foam boards are used in a variety of applications despite the …

Fast Diffusion Of Silver In Tio2 Nanotube Arrays, Wanggang Zhang, Yiming Liu, Diaoyu Zhou, Hui Wang, Wei Liang, Fuqian Yang

Chemical and Materials Engineering Faculty Publications

Using magnetron sputtering and heat treatment, Ag@TiO₂ nanotubes are prepared. The effects of heat-treatment temperature and heating time on the evolution of Ag nanofilms on the surface of TiO₂ nanotubes and microstructure of Ag nanofilms are investigated by X-ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy. Ag atoms migrate mainly on the outmost surface of the TiO₂ nanotubes, and fast diffusion of Ag atoms is observed. The diffusivity for the diffusion of Ag atoms on the outmost surface of the TiO₂ nanotubes at 400 °C is 6.87 × 10⁻¹⁸ m²/s, …

Studies On Nanocomposite Coating Produced By Laser-Assisted Process To Prevent Silicone Hydrogels From Bio-Fouling, Vishnuvardhana Wuppaladhodi

Electronic Thesis and Dissertation Repository

In this thesis, silver nanoparticles incorporated into polyvinylpyrrolidone (PVP) were deposited on silicone hydrogel to improve the hydrophilicity of the silicone hydrogel and prevent the growth of bacteria. Two different processes were employed to produce Ag nanoparticles: (1) Process-A is a photochemical reduction; (2) Process-B is laser ablation in liquid. Following that, MAPLE process was employed to deposit the Ag-PVP nanocomposites on the surface of silicone hydrogel. A solid-state pulsed laser (Nd:YAG) with a wavelength of 532 nm at a fluence of 50.4 mJ/cm² was used in the MAPLE system to deposit Ag-PVP nanocomposite coating. Our results indicate that …

Apparent Porosity And Compressive Strength Of Heat-Treated Clay/Iron Sand/Rice Husk Ash Composites Over A Range Of Sintering Temperatures, M. Nizar Machmud, Zulkarnain Jalil, Mochammad Afifuddin

Makara Journal of Technology

Novel composites of clay/iron sand/rice husk ash (RHA) have been developed. Electric furnace was used to perform heat treatment on the composites to study the effect of sintering temperature on their apparent porosity and compressive strength. Two types of RHA with different bulk density were prepared to gain an understanding of the influence of apparent porosity on compressive strength of the heat-treated composites over a range of sintering temperatures. Heattreated composites, made of clay/iron sand and clay/RHA, were also prepared as a referenced material. X-ray diffraction (XRD) analysis was further performed to comprehensively discuss the role of iron sand on …

Automatic Arrhythmia Beat Detection: Algorithm, System, And Implementation, Wisnu Jatmiko, I Md. Agus Setiawan, Muhammad Ali Akbar, Muhammad Eka Suryana, Yulistiyan Wardhana, Muhammad Febrian Rachmadi

Makara Journal of Technology

Cardiac disease is one of the major causes of death in the world. Early diagnose of the symptoms depends on abnormality on heart beat pattern, known as Arrhythmia. A novel fuzzy neuro generalized learning vector quantization for automatic Arrhythmia heart beat classification is proposed. The algorithm is an extension from the GLVQ algorithm that employs a fuzzy logic concept as the discriminant function in order to develop a robust algorithm and improve the classification performance. The algorithm is tested against MIT-BIH arrhythmia database to measure the performance. Based on the experiment result, FN-GLVQ is able to increase the accuracy of …

The Effect Of Irradiation Of Fe And Ar Ion On The Surface Morphology Of Diamond Thin Film Related To The Magnetoresistance Property, Salim Mustofa, Setyo Purwanto, Kenji Mishima

Makara Journal of Technology

The irradiation of Fe and Ar ion was applied on the surface of diamond/Si thin film to know its effect on the morphology of thin film.The magnetoresistance property was also studied. Ion irradiation treatment using Fe ion followed by argon ion at the energy of 70keV and a dose of 1 x 1015 ion/cm2 have been conducted on the surface of two types of thin film, diamond/Si (111) and diamond/Si (100). Both thin films were made by using a CVD method, and the thickness of the thin film is 1000-nm. From simulations using the software called Stopping and Range of …

Use Of Green Mussel Shell As A Desulfurizer In The Blending Of Low Rank Coal-Biomass Briquette Combustion, Mahidin Mahidin, Asri Gani, M. Reza Hani, Muhammad Syukur, Hamdani Hamdani, Khairil Khairil, Samsul Rizal, Abdul Hadi, T.M.I. Mahlia

Makara Journal of Technology

Calcium oxide-based material is available abundantly and naturally. A potential resource of that material comes from marine mollusk shell such as clams, scallops, mussels, oysters, winkles and nerites. The CaO-based material has exhibited a good performance as the desulfurizer or adsorbent in coal combustion in order to reduce SO2 emission. In this study, pulverized green mussel shell, without calcination, was utilized as the desulfurizer in the briquette produced from a mixture of low rank coal and palm kernel shell (PKS), also known as bio-briquette. The ratio of coal to PKS in the briquette was 90:10 (wt/wt). The influence of green …

Study On Oil Palm Fresh Fruit Bunch Bruise In Harvesting And Transportation To Quality, Andreas Wahyu Krisdiarto, Lilik Sutiarso

Makara Journal of Technology

There are losses of production due to oil palm field’s material handling. Activities that may raise the losses are harvesting and transportation, which may cause bruise and damage to fruit. This research was aimed to learn the bruise of fresh fruit bunch (FFB) phenomenon in harvesting and transportation. Method used in this research was measuring the bruise area resulted by FFB falling when harvested, loading (throwing up) FFB to truck bin, and transporting using truck. These data, coupled with weight of bruised fruit, were calculated to get FFB bruise index. Each FFB bruise index is related to potential free fatty …

Optimization Of Electricity Generation Schemes In The Java-Bali Grid System With Co2 Reduction Consideration, Farizal Farizal, Wenty Eka Septia, Amar Rachman, Nasruddin Nasruddin, Teuku Meurah Indra Mahlia

Makara Journal of Technology

This research considers the problem of reducing CO2 emissions from the Java-Bali power grid system that consists of a variety of power-generating plants: coal-fired, natural gas, oil, and renewable energy (PV, geothermal, hydroelectric, wind, and landfill gas). The problem is formulated as linear programming and solved using LINGO 10. The model was developed for a nation to meet a specified CO2 emission target. Two carbon dioxide mitigation options are considered in this study, i.e. fuel balancing and fuel switching. In order to reduce the CO2 emissions by 26% in 2021, State Electric Supply Company (PLN) has to generate up to …

The Knowledge-Based Analysis On Medium Resolution Images Of Remote Sensing To Extraction Information Land Use Type Scs-Cn, The Case Study On Grompol Watershed, Puguh Dwi Raharjo, Totok Gunawan, Mohammad Pramono Hadi

Makara Journal of Technology

Remote sensing imagery Landsat-8 is one image that has a good temporal resolution; in addition to the availability of data, this image can be obtained free of charge. Land cover type SCS-CN is part of a unit of land that affects runoff. The use of medium resolution imagery in reducing the SCS-CN land use type is considered relatively difficult, and it yields less good accuracy. Limitations on multispectral classification only rely on facts derived from spectral reflection, so that the two data are the same since different characteristic results are not so good. This study aims to determine the accuracy …

Sugarcane Bagasse As A Carrier For The Immobilization Of Saccharomyces Cerevisiaein Bioethanol Production, Sita Heris Anita, Wibowo Mangunwardoyo, Yopi Yopi

Makara Journal of Technology

Sugarcane bagasse was used as a carrier to immobilize Saccharomyces cerevisiae in bioethanol production. This research aims to study the potential use of sugarcane bagasse as an alternative carrier for cell immobilization and improvement in the production process of cell immobilization in bagasse. The results showed that the physical characteristics of sugarcane bagasse as a carrier were water content (7.77 ± 0.35%), water retention (4.80 ± 0.44 g/g), water absorption index (8.58 ± 0.22 g/g), and lignin content (24.40 ± 1.52 %). Determination of cell retention was performed in an inoculum volume of 50 mL yeast suspension with various carrier …

Fundamental Understanding Of Bond Formation During Solid State Welding Of Dissimilar Metals, Niyanth S

Doctoral Dissertations

Dissimilar metal welds are used in a wide range of applications to effect light weighting and for corrosion resistance. While fusion welding techniques are limited in their ability to fabricate dissimilar metal welds, solid state welding techniques are limited in their ability to fabricate complex geometries with dissimilar metal combinations. Hence alternative techniques need to be explored to fabricate complex geometries with dissimilar metals welds in the solid state. Ultrasonic additive manufacturing in a solid state additive manufacturing process that combines ultrasonic welding with mechanized tape layering to fabricate dissimilar metal welds in the solid state. Though extensive feasibility studies …

Characterizing Local Order And Physical Properties Of Rare Earth Complex Oxides, Thomas Jacob Shamblin

Doctoral Dissertations

With more than 500 compositions, materials possessing the pyrochlore structure have a myriad of technological applications and physical phenomena. Three of the most noteworthy properties are the structure’s ability to resist amorphization making it a possible host matrix for spent nuclear fuel, its exotic magnetic properties arising from geometric frustration, and fast ionic conductivity for solid-oxide fuel cell applications. This work focuses on these three aspects of the pyrochlore’s many potential uses. Structural characterization revealed that pyrochlore-type oxides have a tendency to disorder from a high symmetry cubic structure to a lower symmetry orthorhombic arrangement in response to a variety …

Material And Process Engineering For Bulk Single Crystal Growth Of High Performance Scintillator Potassium Calcium Iodide, Adam Coleman Lindsey

Doctoral Dissertations

Protection against threats of nuclear terrorism relies on the deployment of an enormous number of radiation detection devices with energy resolution to differentiate the radiological signatures of special nuclear materials amongst naturally occurring radiation and other nuisance sources. The capabilities of these devices rely upon the availability of high performance scintillator and semiconductor materials which provide useful responses in the presence of radiation. So far, few materials have been developed to a level that can supplant the use of underperforming NaI:Tl [thallium doped sodium iodide] crystals in the field due to their high cost and/or low yields of production. KCaI …

Lignin-Based Li-Ion Anode Materials Synthesized From Low-Cost Renewable Resources, Nicholas William Mcnutt

Doctoral Dissertations

In today’s world, the demand for novel methods of energy storage is increasing rapidly, particularly with the rise of portable electronic devices, electric vehicles, and the personal consumption and storage of solar energy. While other technologies have arguably improved at a rate that is exponential in accordance with Moore’s law, battery technology has lagged behind largely due to the difficulty in devising new electric storage systems that are simultaneously high performing, inexpensive, and safe.

In order to tackle these challenges, novel Li-ion battery anodes have been developed at Oak Ridge National Laboratory that are made from lignin, a low-cost, renewable …

Representative Volume Element (Rve) Finite-Element Analysis (Fea) Of Al Metal-Matrix Composites, Yuzhe Cao

Theses and Dissertations

ABSTRACT

REPRESENTATIVE VOLUME ELEMENT (RVE) FINITE-ELEMENT ANALYSIS

(FEA) OF AL METAL-MATRIX COMPOSITES

by

Yuzhe Cao

The University of Wisconsin-Milwaukee, 2016

Under the Supervision of Professor Chang-Soo Kim

Metal matrix composites reinforced by particles (a.k.a particle reinforced metal matrix composites, PRMMCs) could be suitable for a large number of applications with their enhanced mechanical properties. These composites generally consist of a base metal filled with hard/strong particles of which physical and mechanical properties very different from those of the matrix. These particles are intended to improve the properties of the base material including wear resistance, damping properties, and mechanical strength. Aluminum …