Materials Science and Engineering Commons^™

Titanium Aluminum Nitride Films Deposited By Ac Reactive Magnetron Sputtering: Study Of Positioning Effect In An Inverted Cylindrical Magentron Sputtering System, George C. Vandross Ii

Graduate Theses and Dissertations

TiAlN films were deposited on glass substrates by AC magnetron sputtering at 2 kW with constant Argon and Nitrogen gas flow rates to study the effects of positioning on the deposited films. The deposition system used was an ICM-10 IsoFlux cylindrical magnetron sputtering chamber. The samples were placed in different positions and tilts with respect to the location of the Titanium and Aluminum targets in the chamber. It was found that with change in position and application of tilts, deposited films acquired different physical and chemical properties. It is believed that the differences in these properties were caused by to …

Synthesis And Characterization Of Nanoscale Fluorescent Polymer Films, Maryus Chyasnavichyus

All Dissertations

Performance of the chemical sensing devices is based sensitivity to the targeted analytes and accuracy of the measurements. Of many different types of chemical sensors, fluorescence based sensing devices draw much attention as efficient yet small and straightforward devices, capable of detection of various analytes at extremely small quantities.
Polymeric materials provide support for the fluorescent materials and usually serve as a host for the chromophores, protecting them from harsh environments, and serve as a transport media for the analyte.
In the present study thin fluorescent polymer films, sensitive to the environment are synthesized and studied. Poly(glycidyl methacrylate) was used …

A Silicon Carbide Based Solid-State Fault Current Limiter For Modern Power Distribution Systems, Erik Darnell Johnson

Graduate Theses and Dissertations

The fault current limiter represents a developing technology which will greatly improve the reliability and stability of the power grid. By reducing the magnitude of fault currents in distribution systems, fault current limiters can alleviate much of the damage imposed by these events. Solid-state fault current limiters in particular offer many improved capabilities in comparison to the power system protection equipment which is currently being used for fault current mitigation. The use of silicon carbide power semiconductor devices in solid-state fault current limiters produces a system that would help to advance the infrastructure of the electric grid.

A solid-state fault …

Complex Of Myoglobin With Phenol Bound In A Proximal Cavity, Xiao Huang, Chunxue Wang, Lesa R. Celeste, Leslie L. Lovelace, Shengfang Sun, John H. Dawson, Lukasz Lebioda

Faculty Publications

Sperm whale myoglobin (Mb) has weak dehaloperoxidase activity and catalyzes the peroxidative dehalogenation of 2,4,6-trichlorophenol (TCP) to 2,6-dichloroquinone. Crystals of Mb and of its more active G65T variant were used to study the binding of TCP, 4-iodophenol (4-IP) and phenol. The structures of crystals soaked overnight in a 10 mM solution of phenol revealed that a phenol molecule binds in the proximal cavity, forming a hydrogen bond to the hydroxyl of Tyr146 and hydrophobic contacts which include interactions with C and C of the proximal histidine His93. The phenol position corresponds to the strongest xenon binding site, Xe1. It …

Incorporation Of Catalytic Dehydrogenation Into Fischer-Tropsch Synthesis To Significantly Reduce Carbon Dioxide Emissions, Gerald P. Huffman

Chemical and Materials Engineering Faculty Patents

A new method of producing liquid transportation fuels from coal and other hydrocarbons that significantly reduces carbon dioxide emissions by combining Fischer-Tropsch synthesis with catalytic dehydrogenation is claimed. Catalytic dehydrogenation (CDH) of the gaseous products (C1-C4) of Fischer-Tropsch synthesis (FTS) can produce large quantities of hydrogen while converting the carbon to multi-walled carbon nanotubes (MWCNT). Incorporation of CDH into a FTS-CDH plant converting coal to liquid fuels can eliminate all or most of the CO₂ emissions from the water-gas shift (WGS) reaction that is currently used to elevate the H₂ level of coal-derived syngas for FTS. Additionally, the …

Physico-Chemical, And Sensory Properties Of Soy Based Gouda Cheese Analog Made From Different Concentration Of Fat, Sodium Citrate And Various Cheese Starter Cultures, Abu Amar, Ingrid Suryanti Surono

Makara Journal of Technology

Gouda cheese analog (GCA) was made using soy protein isolate (SPI), skim milk powder (SMP), fat (palm fat and butter fat), and water (W) at optimal ratio of SPI : SMP : F : W = 14 : 6 : 20 : 60. The effects of butter fat, sodium citrate, and cheese starter culture on the sensory properties of ripened product were assessed by preference test, hedonic test, and the texture profile analysis (TPA) of GCA. The free fatty acids, water-soluble nitrogen, and reduction in pH value of progel were also measured. The use of 100% butter fat (BF) produced …

Effects Of Deposition Parameters And Oxygen Addition On Properties Of Sputtered Indium Tin Oxide Films, Badrul Munir, Rachmat Adhi Wibowo, Kim Kyoo Ho

Makara Journal of Technology

Indium tin oxide (ITO) films were sputtered on corning glass substrate. Oxygen admixture and sputtering deposition parameters were optimized to obtain the highest transparency as well as lowest resistivity. Structural, electrical and optical properties of the films were then examined. Increasing deposition rate and film thickness changed the crystallographic orientation from (222) to (400) and (440), as well as higher surface roughness. It was necessary to apply substrate heating during reposition to get films with better crystallinity. The lowest resistivity of 5.36 x 10-4 Ω•cm was obtained at 750 nm film thickness. The films’ resistivity was increased by addition of …

The Effect Of Rubber Mixing Process On The Curing Characteristics Of Natural Rubber, Abu Hasan, Rochmadi Rochmadi, Hary Sulistyo, Suharto Honggokusumo

Makara Journal of Technology

This research is aimed at studying the relationship between rubber mixing processes and curing characteristics of natural rubber. The curing characteristic analysis was carried out through a natural rubber formula having been masticated and mixed, followed by curing. As many as four mastication methods were finely applied; each respected four sequences of rubber mixing process. In the first method, rubber was masticated for 5 minutes and then rubber chemicals and carbon black N 330 were simultaneously added. In the second and the third methods, rubber was masticated for 1 minute and then carbon blacks and rubber chemicals were also simultaneously …

Observation Of Center Disaster Damage On Pariaman And Wasior Using Differential Sar Interferometry (Dinsar), Dodi Sudiana, Mia Rizkinia

Makara Journal of Technology

This study focuses on disaster observations in Pariaman (West Sumatera) and Wasior (Papua) using remote sensing techniques (differential SAR interferometry). Differential interferometry (DInSAR) method was performed on two PALSAR data sets with different acquisition months, i.e. about a month after and before disaster, respectively. The center damage of Pariaman earthquake and Wasior flood can be determined by deriving Land Subsidence using DInSAR method.

Coastal Physical Vulnerability Of Surabaya And Its Surrounding Area To Sea Level Rise, Sayidah Sulma, Eko Kusratmoko, Ratna Saraswati

Makara Journal of Technology

The study for coastal vulnerability to sea level rise was carried out in Surabaya and its surrounding area, it has focused on calculations of the physical vulnerability index were used coastal vulnerability index (CVI) methods. It was standardized by the multi criteria analysis (MCA) approach according to the study area. The score of each physical variable derived from remote sensing satellite data and the results of studies that have been done, such as modeling results and thematic maps, and then integrated into geographic information systems (GIS). Result of this study shows that the coastal areas of Gresik, Surabaya, and Sidoarjo …

The Effect Of Size And Crumb Rubber Composition As A Filler With Compatibilizer Pp-G-Ma In Polypropylene Blends And Sir-20 Compound On Mechanical And Thermal Properties, Erna Frida

Makara Journal of Technology

Having been researched the development of thermoplastic elastomer material of polypropylene and natural rubber SIR- 20 compound with Crumb Rubber as the filler. Reinforced polypropylene with size 60 mesh with 1 mm, and the composition of the Crumb rubber (30, 40, and 50) wt%. Observed mechanical properties are tensile strength, fracture elongation, Young's modulus, tear strength and impact strength. Thermal properties are analyzed by DSC and DTA/TGA. It is acquired that for the size of 60 mesh crumb rubber tensile strength, fracture elongation, Young’s modulus, tear strength and impact strength are bigger than 1mm size. The addition of 60 mesh …

Development Of Local-Economic-Development Small And Medium Industries (Led-Sme) In East Java, Rachmad Hidayat, Sabarudin Akhmad

Makara Journal of Technology

This paper presents the effects of Indonesian government’s developmental efforts of assistance and training performed on the growth of LED-SME business units and business performance. Both parameters of the government’s assistance and training were used to analyze the impact to the growth and performance of business unit. To achieve a comprehensive result, samples acquired in this research were about 190 entrepreneurs and managers of LED-SME from East Java. Based on the parameters above, there are five hypotheses made to prove the relationship of the assistance and training to the growth and performance of business units. The structural equation modeling (SEM) …

Cdm Potential In Palm Solid Waste Cogeneration As An Alternative Energy In Aceh Province, Mahidin Mahidin, Izarul Machdar, Muhammad Faisal, Muhammad Nizar

Makara Journal of Technology

Empty Fruit Bunch (EFB) as a solid waste in Crude Palm Oil (CPO) industry does not utilized yet as an alternative energy source to generate electricity. It is well known that use of solid wate (biomass) as an energy source is part of the Clean Development Mechanism (CDM) scheme due to direct reduction of Green House Gases (GHGs) emission and provide a direct contribution to sustainable development. Utilization of EFB as a source of energy is very potential to be implemented in Aceh since this province has 25 CPO Mills at the moment which actively produce about 870,000 ton EFB …

Small Scale Experiment: Thermal Performance Comparison Between Fiber-Cement Roof And Photovoltaic Roof In Malang, Indonesia, Nurhamdoko Bonifacius, Sri Nastiti Nugrahani Ekasiwi

Makara Journal of Technology

Irradiation on the surface of photovoltaic module heats up the photovoltaic module itself and the room underneath the roof of integrated photovoltaic building in the tropics area. Room heating reduces thermal condition and photovoltaic module surface heating reduces its performance in generating electricity. This paper discusses an experiment of measuring the surface temperature of photovoltaic modules and fiber-cement roof surface as a comparison. This experiment also measures the impact of rising temperatures in each space underneath. It used small-scale mock-ups exposed to direct sunlight. The result of the experiment shows that photovoltaic roof surface temperature is lower than fiber-cement roof …

Improved Optical Probe For Measuring Phytoplankton Suspension Concentrations Based On Optical Fluoresensce And Absorption, Retno Wigajatri Purnamaningsih, Nining Betawati Prihantini

Makara Journal of Technology

This paper discusses the results of improved optical probe that works according to optical fluorescence and absorption phenomena for measuring the phytoplankton suspension concentrations. Measurements are made on the Scenedesmus sp. culture. The laboratory test has shown that range of concentration from 104 up to around 1 x 106 cells/mL; fluorescence intensity at λ = 685 nm; and logarithmic of transmission intensity at λ = 405 nm are proportional to the cell concentration linear with proportional constant γ = 4 × 10-5 and β = –2 × 10-7 mL/cell respectively.

Mechanical And Thermal Properties Of Polypropylene Reinforced By Calcined And Uncalcined Zeolite, Nurdin Bukit

Makara Journal of Technology

This study was carried out to compare mechanical and thermal properties of polypropylene (PP) reinforced with uncalcined and calcined zeolites. The PP samples were reinforced with zeolites at various quantities of 2, 4, and 6 (wt %). The comparison of the two types of zeolite was based on mechanical properties, including tensile strength, elongation at break, and Young’s modulus, and thermal characteristics analyzed using DSC, and DTA/TGA technique. The results obtained clearly revealed that both zeolites were able to significantly increase tensile strength and Young’s modulus of the samples, with calcined zeolite was found to work better. Addition of calcined …

Benchmark For Country-Level Earthquake Strong-Motion Instrumentation Program, Widjojo Adi Prakoso, I Nyoman Sukanta

Makara Journal of Technology

An empirical study to develop benchmark models at country-level to assess the suggested number of earthquake strongmotion stations based on a framework encompassing geographic, demographic, and socio-economic parameters is reported. The models are to provide a working estimate of the required number of stations for improving the strongmotion instrumentation program of Indonesia. National earthquake strong-motion networks of New Zealand, Japan, Taiwan, Iran, Turkey, and Italy were used as the references. The parameter proposed is the number of stations in land area of 1,000 km2, and three models based on the exponential regression analysis are presented as functions of population density, …

Worst Case Of Relative Disturbance Gain Array For Uncertain Distillation System, Rudy Agustriyanto, Jie Zhang

Makara Journal of Technology

This article discusses the constrained nonlinear optimization formulation for calculating the worst case of lower and upper bounds of relative disturbance gain array (RDGA) for uncertain process models. The proposed approach seeks the minimum and maximum values of the relative disturbance gains subject to the constraints in which the process and disturbance gains are within their uncertainty ranges. RDGA ranges are useful for control structure determination and the related robustness, as they provide information regarding the sensitivity to gain uncertainties. The proposed method is demonstrated by ternary distillation column case study. Closed loop simulation results support the analysis based on …

Biodiesel Production From Waste Cooking Oil Using Hydrodinamic Cavitation, Muhammad Dani Supardan, Satriana Satriana, Mahlinda Mahlinda

Makara Journal of Technology

The aim of this research was to study biodiesel production from low cost feedstock of waste cooking oil (WCO) using hydrodynamic cavitation apparatus. A two-step processes esterification process and transesterification process using hydrodynamic cavitation for the production of biodiesel from WCO is presented. The first step is acid-catalyzed esterification process for reducing free fatty acid (FFA) content of WCO and followed by base-catalyzed transesterification process for converting WCO to biodiesel as the second step. The result of esterification process with methanol to oil molar ratio of 5 and temperature of 60 oC showed that the initial acid value of WCO …

Knowledge Dictionary For Information Extraction On The Arabic Text Data, Wahyu Syaifullah Jauharis Saputra, Agus Zainal Arifin, Anny Yuniarti

Makara Journal of Technology

Information extraction is an early stage of a process of textual data analysis. Information extraction is required to get information from textual data that can be used for process analysis, such as classification and categorization. A textual data is strongly influenced by the language. Arabic is gaining a significant attention in many studies because Arabic language is very different from others, and in contrast to other languages, tools and research on the Arabic language is still lacking. The information extracted using the knowledge dictionary is a concept of expression. A knowledge dictionary is usually constructed manually by an expert and …

Wolfpack Gear Inc. Composite Frame Firefighter Backpack, Gabriel Mountjoy, Blair Ridings, Carl Drummond Buchenroth

Mechanical Engineering

No abstract provided.

P3ht:Pcpdtbt:Pcbm Multi- Polymer Single Layer Solar Cells, Ted Andreas

Physics

OPV efficiencies are limited by their narrow absorption; rather than using tandem architecture to overcome this obstacle, our group combined P3HT and PCPDTBT into a single layer BHJ solar cell that achieved 2.0% PCE. This is 33% higher than the pure P3HT control from this group, proving that multi-polymer solar cells have the potential to outperform their single-polymer components.

The Oxidation Of Hydrogen Peroxide On Nanostructured Rhodium Microelectrodes, N. Bartlett Philip, F. Esterle Thomas

Journal of Electrochemistry

Mesoporous Rh films were deposited onto platinum microelectrodes from the H₁ lyotropic liquid crystalline phase of C₁₂EO₈ (octaethyleneglycol monododecyl ether). The electrodes show well defined voltammetry for the oxidation and the reduction of hydrogen peroxide at low concentrations (<10 mmol•L-1) with excellent stability for operation at neutral pH. Based on the hysteresis in the current and the potential dependence the oxidation of hydrogen peroxide occurs through a CEE mechanism involving Rh(OH)₃ on the mesoporous Rh electrode surface. At higher hydrogen peroxide concentrations the current reaches a plateau that is due to either saturation of the binding sites for hydrogen peroxide or limitation of the reaction due to acidification of the solution within the pores. For the thin films (below 200 nm) the hydrogen peroxide calibration curves we …

In Situ Pm-Irras Studies Of A Floating Bilayer Lipid Membrane At Au(111) Electrode Surface, Su Zhangfei, Kycia Annia, Jay Leitch J., Lipkowski Jacek

Journal of Electrochemistry

In situ Polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) was used to study the structure of a DMPC + cholesterol + GM1 floating bilayer lipid membrane (fBLM) at a Au(111) surface. 1-thio-beta-D-glucose (beta-Tg) was self-assembled onto the Au electrode to increase the overall hydrophilicity of the surface. The fBLM was deposited on the beta-Tg self-assembled monolayer (SAM) using a combination of Langmuir-Blodgett/Langmuir-Schaefer (LB/LS) techniques. The carbohydrate headgroups of the GM1 molecules were physically adsorbed to the beta-Tg SAM forming a water rich cushion between the fBLM and the modified gold substrate. The PM-IRRAS spectra indicate that the DMPC molecules within …

Electrochemical Synthesis Of Silver-Tetracyanoquinodimethane Nanorods At Agar Supported Water/1,2-Dichloroethane Interface, Li Huang, Yixian Wang, Michael V. Mirkin, Bin Ren, Dongping Zhan

Journal of Electrochemistry

Silver-tetracyanoquinodimethane (AgTCNQ) is an important charge transfer salt due to its high conductivity and other electronic properties. In this communication, we report the synthesis of AgTCNQ at the liquid/liquid interface. Agar was used as a gelling agent to support water/1,2-dichloroethane (DCE) interface. Silver ions were transferred from the hydrogel into DCE phase, where they combined with TCNQ^- to form AgTCNQ nanorods. The developed method can provide a new route for synthesis of functional materials based on the electrochemistry at the liquid/liquid interface.

Efficient And Cost Effective Solar Cells: New Materials For Improved Recombination And Charge Dissociation Losses In Organic Photovoltaics, Jonathan D. Servaites

Link Foundation Energy Fellowship Reports

Solar energy resources are vast: more energy hits the planet in one hour than humankind consumes in entire year. However, solar technologies have only been used to a limited degree in energy production thus far because of high costs.1 Organic solar cells2-21 offer the potential to change the landscape of how we produce and use energy. If developed into a mature technology, they present the opportunity to significantly reduce solar energy costs through earth-abundant materials, efficient installation, and roll-to-roll production. 6-8 Their properties and designs can be tuned and optimized via materials versatility, solution-based processing, and mechanical flexibility.8-10 In recent …

Stress Corrosion Cracking Susceptibility Of Ultrafine Grained Az31, G. R. Argade, W. Yuan, K. Kandasamy, R. S. Mishra

Materials Science and Engineering Faculty Research & Creative Works

In this study, stress corrosion cracking (SCC) behavior of AZ31 magnesium alloy was carried out using slow strain rate testing (SSRT) technique in 3.5 wt.% NaCl solution. the influence of microstructural scale on the stress corrosion behavior was investigated in AZ31 alloy with three different mean grain sizes. Single-pass and two-pass friction stir processing (FSP) was employed to obtain fine grain and ultrafine grain microstructures, respectively. for FSP, SSRT specimens were extracted from the processed region. SSRTs were carried out in air and solution at an initial strain rate of 10 -6/s. a significant decrease in the ultimate tensile strength …

Biaxial Bending And Lateral-Torsional Instability Of Imperfect Frp I-Beams Including Effects Of Retrofitting, Jodi Marie Knorowski

Civil & Environmental Engineering Theses & Dissertations

This thesis presents the outcome of a theoretical and experimental study of the behavior of Fiber Reinforced Polymer (FRP) I-beams susceptible to lateral-torsional instability or when subjected to biaxial bending. Laboratory experiments involved application of vertical and horizontal static loads to a 4 x 4 x ¼ in. I-beam with various lengths, and the resulting displacement, twist, and strain were recorded. In the vertical direction, the beam was loaded from different reference load heights with respect to the shear center of the beam. The governing biaxial flexure and torsion differential equations were modified to account for the presence of initial …

Neural Network Fatigue Life Prediction In Steel I-Beams Using Mathematically Modeled Acoustic Emission Data, Prathikshen Nambiar Selvadorai

Doctoral Dissertations and Master's Theses

The purpose of this research is to predict fatigue cracking in metal beams using mathematically modeled acoustic emission (AE) data. The AE data was collected from nine samples of steel I-beam that were subjected to three-point bending caused by cyclic loading. The data gathered during these tests were filtered in order to remove long duration hits, multiple hit data, and obvious outliers. Based on the duration, energy, amplitude, and average frequency of the AE hits, the filtered data were classified into the various failure mechanisms of metals using NeuralWorks® Professional II/Plus software based self-organizing map (SOM) neural network. The parameters …

Study Of Morphological Changes In Mgh2 Destabilized Libh4 Systems Using Computed X-Ray Microtomography, Tabbetha A. Dobbins, Shathabish Narasegowda, Leslie G. Butler

College of Science & Mathematics Departmental Research

The objective of this study was to apply three-dimensional x-ray microtomographic imaging to understanding morphologies in the diphasic destabilized hydride system: MgH2 and LiBH4. Each of the single phase hydrides as well as two-phase mixtures at LiBH4:MgH2 ratios of 1:3, 1:1, and 2:1 were prepared by high energy ball milling for 5 minutes (with and without 4 mol % TiCl3 catalyst additions). Samples were imaged using computed microtomography in order to (i) establish measurement conditions leading to maximum absorption contrast between the two phases and (ii) determine interfacial volume. The optimal energy for measurement was determined to be 15 keV …