Multifunctional Nanocomposites Based On Bacterial Cellulose,
2018
Washington University in St. Louis
Multifunctional Nanocomposites Based On Bacterial Cellulose, Qisheng Jiang
McKelvey School of Engineering Graduate Student Theses & Dissertations
Cellulose is biodegradable, renewable, and abundant in nature thus cellulose (or paper)-based products can be inexpensively produced and recycled. Among cellulosic materials, bacterial nanocellulose (BNC) draws a special research attention due to the inherent three-dimensional nanofibrous structure, excellent mechanical flexibility, high purity and well-defined surface chemistry, and cost-efficient, scalable and environment-friendly synthesis. BNC can be biosynthesized by Gluconacetobacter xylinus, which is the most characterized BNC producer among various microorganisms. BNC is composed of highly pure cellulose nanofibrils, produced from well-defined dextrose through biochemical steps and subsequent self-assembling of the secreted cellulose fibrils which has the dimension ranges from 25 to …
Multifunctional Nanocomposites Based On Bacterial Cellulose,
2018
Washington University in St. Louis
Multifunctional Nanocomposites Based On Bacterial Cellulose, Qisheng Jiang
McKelvey School of Engineering Graduate Student Theses & Dissertations
Cellulose is biodegradable, renewable, and abundant in nature thus cellulose (or paper)-based products can be inexpensively produced and recycled. Among cellulosic materials, bacterial nanocellulose (BNC) draws a special research attention due to the inherent three-dimensional nanofibrous structure, excellent mechanical flexibility, high purity and well-defined surface chemistry, and cost-efficient, scalable and environment-friendly synthesis. BNC can be biosynthesized by Gluconacetobacter xylinus, which is the most characterized BNC producer among various microorganisms. BNC is composed of highly pure cellulose nanofibrils, produced from well-defined dextrose through biochemical steps and subsequent self-assembling of the secreted cellulose fibrils which has the dimension ranges from 25 to …
Elevated Temperature Progressive Damage And Failure Of Duplex Stainless Steel,
2018
University of New Mexico - Main Campus
Elevated Temperature Progressive Damage And Failure Of Duplex Stainless Steel, Darren P. Luke
Civil Engineering ETDs
Ductile failure of metals has been the focus of research efforts within academia and industry for many years since it is tremendously important for understanding the failure of structures under extreme loading conditions. However, limited research has been dedicated to elevated temperature ductile failure, which is critical for evaluating catastrophic events such as industrial, structural or shipping vessel fires. A detailed investigation was conducted on the structural response of Duplex Stainless Steel at elevated temperatures. The temperature dependence of elastic modulus, yield strength, ultimate strength, and ductility was measured up to 1000°C and a continuum damage plasticity model was developed. …
Economic Potential For Distributed Manufacturing Of Adaptive Aids For Arthritis Patients N The U.S.,
2018
Michigan Technological University
Economic Potential For Distributed Manufacturing Of Adaptive Aids For Arthritis Patients N The U.S., Nicole Gallup, Jennifer Bow, Joshua M. Pearce
Department of Materials Science and Engineering Publications
By 2040, more than a quarter of the U.S. population will have diagnosed arthritic conditions. Adults with arthritis and other rheumatic conditions earn less than average yet have medical care expenditures that are over 12% of average household income. Adaptive aids can help arthritis patients continue to maintain independence and quality of life; however, their high costs limit accessibility for older people and the poor. One method used for consumer price reduction is distributed manufacturing with 3-D printers. In order to assess if such a method would be financially beneficial, this study evaluates the techno-economic viability of distributed manufacturing of …
A Simple And Robust Approach To Reducing Contact Resistance In Organic Transistors,
2018
Wake Forest University
A Simple And Robust Approach To Reducing Contact Resistance In Organic Transistors, Zachary A. Lamport, Katrina J. Barth, Hyunsu Lee, Eliot Gann, Sebastian Engmann, Hu Chen, Martin Guthold, Iain Mcculloch, John E. Anthony, Lee J. Richter, Dean M. Delongchamp, Oana D. Jurchescu
Chemistry Faculty Publications
Efficient injection of charge carriers from the contacts into the semiconductor layer is crucial for achieving high-performance organic devices. The potential drop necessary to accomplish this process yields a resistance associated with the contacts, namely the contact resistance. A large contact resistance can limit the operation of devices and even lead to inaccuracies in the extraction of the device parameters. Here, we demonstrate a simple and efficient strategy for reducing the contact resistance in organic thin-film transistors by more than an order of magnitude by creating high work function domains at the surface of the injecting electrodes to promote channels …
Ascorbic Acid Degradation In Cut Lemon Packaged Using Oxygen Scavenging Active Film During Storage,
2018
Department of Agricultural Engineering, Universitas Mataram, Mataram 83125, Nusa Tenggara Barat
Ascorbic Acid Degradation In Cut Lemon Packaged Using Oxygen Scavenging Active Film During Storage, Kurniawan Yuniarto, Setyo Purwanto, Bruce Ari Welt, Anang Lastriyanto
Makara Journal of Technology
Oxygen scavenging active film can be used to prevent diffusion of free oxygen due to the action of permeation mechanism. In this study, biodegradable oxygen scavenging plastic film was designed by incorporating an antioxidant agent into plasticized polylactic acid or PLA-PEG (PPLA). Butylated hydroxytoluene (BHT) was added at different concentrations into the matrix of the PPLA film using a direct casting method to produce oxygen scavenging active film. The antiradical activity of the oxygen scavenging active film was observed, which could be applied for preventing vitamin C degradation in cut lemon during storage. The antiradical activity of the active film …
Conversion Of Heat Energy From Cooling Water Of Diesel Engine To Electrical Energy Using Thermoelectric Generator,
2018
Department of Mechanical Engineering, Politeknik Negeri Batam, Batam 29461, Indonesia
Conversion Of Heat Energy From Cooling Water Of Diesel Engine To Electrical Energy Using Thermoelectric Generator, Muhammad Hasan Albana
Makara Journal of Technology
This research objective is to convert heat from the radiator fluid of a diesel engine to electrical energy by utilizing a thermoelectric generator (TEG). The TEG consists of 20 semiconductors (TE modules) and is equipped with a heat sink. The research shows that using the TEG, the heat of radiator fluid can be converted to electrical energy, although the electricity generated is small. The maximum electrical voltage generated by the TEG when modules were connected in series was 10 volts. When the TE modules were connected in parallel and series-parallel, the maximum voltages generated were 2.11 and 2.53 volts, respectively. …
Immittance Response On Carboxymethyl Cellulose Blend With Polyvinyl Alcohol- Doped Ammonium Bromide-Based Biopolymer Electrolyte,
2018
Ionic Materials Team, Faculty of Industrial Sciences & Technology, University Malaysia, Pahang 26300, Malaysia
Immittance Response On Carboxymethyl Cellulose Blend With Polyvinyl Alcohol- Doped Ammonium Bromide-Based Biopolymer Electrolyte, Norfatihah Mazuki, Yuki Nagao, Ahmad Salihin Samsudin
Makara Journal of Technology
The blended carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVA) doped with various compositions of ammonium bromide (NH4Br)-based solid biopolymer electrolytes (SBEs) were prepared by using the casting method. In this present work, CMC/PVA–NH4Br SBE thin film was used to investigate the electrical conductivity via electrical impedance spectroscopy. The maximum conductivity obtained was 3.21 X 10−4 S cm−1 for sample AB20 at ambient temperature (303 K), and this result might be due to the increased number of charge carrier. A dielectric study was conducted to understand the conductivity behavior. The electrical properties have been measured as a function of frequency of …
Transition Metal Dichalcogenide For High-Performance Electrode Of Supercapacitor,
2018
Material Technology Programme, Faculty of Industrial Sciences & Technology, Universiti Malaysia Pahang, Lebuhraya Tun Razak, Gambang 26300, Malaysia
Transition Metal Dichalcogenide For High-Performance Electrode Of Supercapacitor, Saifful Kamaluddin Muzakir, Ahmad Salihin Samsudin, Bouchta Sahraoui
Makara Journal of Technology
Molybdenum dichalcogenides have been reviewed from the perspectives of bandgap, conductivity, and oxidation states of transition metal. Researchers have concluded that a narrow-bandgap transition metal dichalcogenide with high conductivity could be achieved for the high-performance electrode of a supercapacitor.
The Importance Of Usability Aspect In M-Commerce Application For Satisfaction And Continuance Intention,
2018
Department of Industrial Engineering, Faculty of Industrial Technology, Institut Teknologi Bandung, Bandung 40132, Indonesia
The Importance Of Usability Aspect In M-Commerce Application For Satisfaction And Continuance Intention, Yassierli Yassierli, Vinsensius Vinsensius, M. S. Syed Mohamed
Makara Journal of Technology
There has been a rapid growing of m-commerce application in recent years due to the development of mobile communication technology and e-commerce business. However, only about 30% of online users, who conduct online searching, make online purchases. The low conversion rate seems to be correlated with poor usability aspect of most m-commerce applications and poor satisfaction reported by users. Research has reported that satisfaction and continuance intention in using m-commerce applications have relationships with service quality and information quality. In this study, a new model of user satisfaction and continuance intention in the context of mobile application was proposed by …
A 2.3/3.3-Ghz Dual Band Low Noise Amplifier Using Switchable Load Inductor In 0.18-Um Cmos Technology,
2018
Department of Electrical Engineering, Faculty of Engineering, Universitas Indonesia, Depok 16424, Indonesia
A 2.3/3.3-Ghz Dual Band Low Noise Amplifier Using Switchable Load Inductor In 0.18-Um Cmos Technology, Taufiq Alif Kurniawan, Hsiao-Chin Chen
Makara Journal of Technology
In this paper, the dual band low noise amplifier is designed in 0.18-μm CMOS technology. By combining the proposed switchable load inductor for gain controlling and the conventional inductive source degeneration topology, narrow band gain and good impedance matching are achieved at 2.3/3.3-GHz frequency bands. The new mathematical analysis of low noise amplifier design is derived to define the component parameters of the proposed circuits. The proposed low noise amplifier exhibits gain of 17.18 dB and 15.5 dB, and noise figure of 2.67 dB and 2.52 dB at the two frequency bands, respectively.
Automated Compilation Test System For Embedded System,
2018
School of Electrical and Electronic Engineering, University Sains Malaysia, Nibong Tebal, 14300 Penang, Malaysia
Automated Compilation Test System For Embedded System, Mohamad Khairi Ishak, Ooi Jun Hwan, Teh Jiashen, Nor Ashidi Mat Isa
Makara Journal of Technology
Embedded system testing involves testing an integration of software and hardware. It is increasingly difficult to evaluate the functionality of each module within a short time because of the increasing number of tests required. In this paper, a novel stepwise methodology involving the use of an automated compilation test system (ACTS) is proposed, to improve the quality of testing and optimize the testing time using automation. Using the proposed method, the testing coverage can be maximized, while minimizing the manual work and testing time required. This ACTS was used to automate the test code compilation and execution for different hardware …
Activated Carbon Fixed-Bed Adsorber Design For Treating Chromium Hexavalent Wastewater,
2018
Department of Chemical Engineering, Faculty of Industrial Technology, Universitas Katolik Parahyangan, Bandung 40141, Indonesia
Activated Carbon Fixed-Bed Adsorber Design For Treating Chromium Hexavalent Wastewater, Tedi Hudaya, Velicia Rachmat
Makara Journal of Technology
Pollution caused by industrial wastewater containing heavy metals is a major issue, primarily due to its toxic nature. A cheap yet effective method to deal with such wastewater is activated carbon adsorption. The purpose of this research is to evaluate and design a fixed bed adsorber with granular activated carbon as an adsorbent to process wastewater-containing chromium hexavalent (Cr 6+). Experiments show that the Langmuir isotherm fits the equilibrium data as effectively as the Freundlich isotherm. Activated carbon used in this research is Jacobi 2000® derived from bituminous coal. The lab scale inlet volumetric flow is 100 mL/h with different …
Polyhedral Oligomeric Silsesquioxane-Phosphate Glass Matrix Nanocomposites With Additional Chapter On Phosphate Glass-Poly(Ethylene Terephthalate) Matrix Composites,
2018
University of Southern Mississippi
Polyhedral Oligomeric Silsesquioxane-Phosphate Glass Matrix Nanocomposites With Additional Chapter On Phosphate Glass-Poly(Ethylene Terephthalate) Matrix Composites, Kyoungtae Kim
Dissertations
Preparation and characterization of tin fluorophosphate glass (Pglass) matrix nanocomposites incorporating polyhedral oligomeric silsesquioxane (POSS) were investigated on the structural, thermal, morphological, mechanical, and rheological properties. Various processes including synthesis, extrusion and sintering processes were applied to prepare the nanocomposite samples. Another application of POSS with hydrophobic functional groups on the well-structured nanoscale silicate cage with three silanol groups was investigated to present the feasibility to use POSS molecule as a coating material on the surface of the hydrophilic inorganic glass. In addition, Poly(ethylene terephthalate) polymer matrix composites incorporating Pglass was studied to present the benefits of the Pglass with …
Hydrogen Bond Mediated Water Structuring, Diffusion, And Elastic Properties In Acrylamide Copolymer Glycohydrogels,
2018
University of Southern Mississippi
Hydrogen Bond Mediated Water Structuring, Diffusion, And Elastic Properties In Acrylamide Copolymer Glycohydrogels, April Levu Fogel
Dissertations
Glycohydrogels have recently gained considerable interest as biocompatible and high water content hydrogels that have similar physicochemical nature to the cell membrane, making them ideal materials for targeted biomedical and personal care applications (e.g., drug delivery systems, biosensors, and contact lenses). Regardless of the specific application, water-polymer and water-water hydrogen bonding interactions have been shown to dictate hydration stability and diffusional properties in traditional hydrogel architectures (e.g., crosslinked HEMA). However, due to the development of glycohydrogel materials within the past two decades, most literature focuses on synthetic techniques and general hydration characteristics. Furthermore, scant literature examines the effect of hydrophobically …
Optimization And Validation Of Efficient Models For Predicting Polythiophene Self-Assembly,
2018
Boise State University
Optimization And Validation Of Efficient Models For Predicting Polythiophene Self-Assembly, Evan D. Miller, Matthew L. Jones, Michael M. Henry, Paul Chery, Kyle Miller, Eric Jankowski
Materials Science and Engineering Faculty Publications and Presentations
We develop an optimized force-field for poly(3-hexylthiophene) (P3HT) and demonstrate its utility for predicting thermodynamic self-assembly. In particular, we consider short oligomer chains, model electrostatics and solvent implicitly, and coarsely model solvent evaporation. We quantify the performance of our model to determine what the optimal system sizes are for exploring self-assembly at combinations of state variables. We perform molecular dynamics simulations to predict the self-assembly of P3HT at ~350 combinations of temperature and solvent quality. Our structural calculations predict that the highest degrees of order are obtained with good solvents just below the melting temperature. We find our model produces …
Young’S Modulus As A Measurement To Estimate Damage Related With Alkali-Silica Reaction In Concrete.,
2018
University of Arkansas, Fayetteville
Young’S Modulus As A Measurement To Estimate Damage Related With Alkali-Silica Reaction In Concrete., Anazaria J. Ortega Gonzalez
Civil Engineering Undergraduate Honors Theses
The main purpose of this research is to compare two nondestructive methods to assess Alkali-Silica reaction (ASR) in concrete. Fifteen concrete prisms were cast using aggregates with different Alkali-Silica reactivity such as Jobe sand and Van Buren sand. The change in strain, shear wave velocity and Young’s modulus were determined according to ASTM C129 and ASTM C215, respectively. This data was collected by Dillon K Self, who determined that the shear wave velocity and strain are inversely proportional. However, when single cracking in the concrete specimen transition to map cracking, the shear wave velocity dropped significantly, whereas the strain value …
Thermodynamic And Phase-Field Analysis Of Domain Structures And Switching Kinetics Of Bismuth Ferrite Thin Films,
2018
University of Texas at Arlington
Thermodynamic And Phase-Field Analysis Of Domain Structures And Switching Kinetics Of Bismuth Ferrite Thin Films, Ryan T. Hart
Material Science and Engineering Theses - Archive
In this study, thermodynamic analysis and phase field simulation are utilized to study the polarization, phase transitions, and phase coexistence in BFO thin films. The effect of temperature, substrate strain, and electrical bias on the phase stability and the phase transformation pathways were studied. Existing thermodynamic analysis methods are supplemented by a phase destrain model, which determines free energy minima as a function of biaxial strain and the fractions of BFO’s ferroelectric phases in a thin film. The results of this methodology are compared with phase field modeling. The phase de-strain model shows reasonable accuracy in determining boundaries at which …
Optimization Of The Practice Of Slow Cooling Steel Bars: A Redesign And Modernization Of Materials,
2018
University of Arkansas, Fayetteville
Optimization Of The Practice Of Slow Cooling Steel Bars: A Redesign And Modernization Of Materials, Eryn Johnston
Mechanical Engineering Undergraduate Honors Theses
Throughout the process of steel making, certain grades of steel are a higher risk for defects caused by the inability to quickly diffuse hydrogen through the steel when cooled to room temperature at a normal rate based on the ambient air temperature. To reduce the hydrogen flaking defects that are caused due to hydrogen entrapment in the steel, the process of slow cooling is utilized. This process reduces the cooling rate of steel bars by keeping them at a higher temperature for extended periods and in turn gives the hydrogen a chance to fully dissipate from the steel. In many …
Phase Separation Dynamics And Morphologies Prediction Of Peo-B-Pmma Copolymer By Atomistic And Mesoscopic Simulations,
2018
Chulalongkorn University
Phase Separation Dynamics And Morphologies Prediction Of Peo-B-Pmma Copolymer By Atomistic And Mesoscopic Simulations, N Chiangraeng, V S. Lee, P Nimmanpipug
Journal of Metals, Materials and Minerals
Atomistic and mesoscopic simulations are the most important tools to predict the morphologies of block copolymers. In this study, inter-bead interactions and essential parameters for meso-structure polymeric models were optimized for poly(ethylene oxide)-block-poly(methyl methacrylate) (PEO-b-PMMA; O-b-M) binary systems. A coarse-grained model in a mesoscopic dynamic was used to represent polymeric chain. Gaussian chain is calculated from polymer chain length concerning its characteristic properties. Free energy density was considered by setting suitable time steps and inter-bead interactions for meso-structure simulations. The interaction energies of 1:1, 2:1 and 4:1 molar ratio of O to M segments were 3.67, 4.66, and 5.92, respectively. …
