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2019

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Articles 691 - 720 of 10505

Full-Text Articles in Engineering

A Comparison Of The Army Corps Of Engineers Hydrologic Modeling System And Autodesk Storm And Sanitary Analysis For Hydraulic And Hydrologic Analysis And Design, Foster Josef Heifetz Campbell Dec 2019

A Comparison Of The Army Corps Of Engineers Hydrologic Modeling System And Autodesk Storm And Sanitary Analysis For Hydraulic And Hydrologic Analysis And Design, Foster Josef Heifetz Campbell

Master's Theses

Hydrological and hydraulic effects of urban development is one of the key issues of study for improved water management. The addition of impervious surfaces to once pervious land and re-routing open channels and flow paths can cause flooding or declining water levels within a watershed. Many studies of these issues have found that there can be multiple factors causing hydrological and hydraulic impacts, and it can be hard to analyze and develop effective solutions without appropriate drainage software packages. However, there are multiple software packages available for use, and determining the correct one to use for a specific challenge can …


Hybrid Iii 95th Percentile Large Male Finite Element Model Neck Alteration, Eric Riley Day Dec 2019

Hybrid Iii 95th Percentile Large Male Finite Element Model Neck Alteration, Eric Riley Day

Master's Theses

The motivation behind the project was to update the Livermore Software Technology Corporation (LSTC) Hybrid III 95th percentile finite element model, such that the neck assembly response under varying simulated loading conditions equals that of the federally regulated Hybrid III 95th percentile anthropomorphic testing device (ATD).

The family of Hybrid III crash test dummies approximate the physical properties and response of the human body in a frontal automotive crash. The Hybrid III is used to assess the effectiveness of vehicle restraint systems. LSTC offers Hybrid III finite element models for use in their Multiphysics simulation software package, LS-DYNA. The Hybrid …


Development Of An Analysis Tool And Weight Estimation Method For Aircraft Wing Structures, Kevin M. Barton Dec 2019

Development Of An Analysis Tool And Weight Estimation Method For Aircraft Wing Structures, Kevin M. Barton

Master's Theses

The goal of this effort was to build an analysis tool for aircraft wings and incorporate it into a program that optimizes the wing structure for the lowest weight for the conceptual design phase. The analysis tool calculates the internal stresses in primary load carrying members using established analysis methods for semimonocoque beams. Via a Graphical User Interface (GUI) built in MATLAB, the user can define the structural layout and material properties of the load carrying members. The program requires a degenerate geometry model built with Vehicle Sketch Pad (OpenVSP) to define the outer mold line (OML) of the wing, …


Design, Modeling And Control Of A Two-Wheel Balancing Robot Driven By Bldc Motors, Charles T. Refvem Dec 2019

Design, Modeling And Control Of A Two-Wheel Balancing Robot Driven By Bldc Motors, Charles T. Refvem

Master's Theses

The focus of this document is on the design, modeling, and control of a self-balancing two wheel robot, hereafter referred to as the balance bot, driven by independent brushless DC (BLDC) motors. The balance bot frame is composed of stacked layers allowing a lightweight, modular, and rigid mechanical design. The robot is actuated by a pair of brushless DC motors equipped with Hall effect sensors and encoders allowing determination of the angle and angular velocity of each wheel. Absolute orientation measurement is accomplished using a full 9-axis IMU consisting of a 3-axis gyroscope, a 3-axis accelerometer, and a 3-axis magnetometer. …


Electropermeabilization Does Not Correlate With Plasma Membrane Lipid Oxidation, Olga Michel, Andrei G. Pakhomov, Maura Casciola, Jolanta Saczko, Julita Kulbacka, Olga N. Pakhomova Dec 2019

Electropermeabilization Does Not Correlate With Plasma Membrane Lipid Oxidation, Olga Michel, Andrei G. Pakhomov, Maura Casciola, Jolanta Saczko, Julita Kulbacka, Olga N. Pakhomova

Bioelectrics Publications

The permeabilized condition of the cell membrane after electroporation can last minutes but the underlying mechanisms remain elusive. Previous studies suggest that lipid peroxidation could be responsible for the lasting leaky state of the membrane. The present study aims to link oxidation within the plasma membrane of live cells to permeabilization by electric pulses. We have introduced a method for the detection of oxidation by ratiometric fluorescence measurements of BODIPY-C11 dye using total internal reflection fluorescence (TIRF) microscopy, limiting the signal to the cell membrane. CHO-K1 cells were cultured on glass coverslips coated with an electroconductive indium tin oxide (ITO) …


The Capacity Of Chennai International Airport: A Study, K P Sooraj Dec 2019

The Capacity Of Chennai International Airport: A Study, K P Sooraj

Manipal Journal of Science and Technology

This paper discusses a case study of the capacity of the Chennai International Airport. The capacity of an airport is an important determinant for implementation of Air Traffic Flow Management (ATFM), departure/arrival slot allocation, etc. and is a key input while estimating when the airport will saturate, in order to plan additional infrastructure, at places where catchment area population is not the limiting factor. The simulation model layout of the airport was considered for the study. Total airport delay such as gate delay, TWY delay, seq. delay, RWY delay, posing delay, and total delay for the base model and capacity …


Evaluating The Resiliency Of Industrial Internet Of Things Process Control Using Protocol Agnostic Attacks, Hector L. Roldan Dec 2019

Evaluating The Resiliency Of Industrial Internet Of Things Process Control Using Protocol Agnostic Attacks, Hector L. Roldan

Theses and Dissertations

Improving and defending our nation's critical infrastructure has been a challenge for quite some time. A malfunctioning or stoppage of any one of these systems could result in hazardous conditions on its supporting populace leading to widespread damage, injury, and even death. The protection of such systems has been mandated by the Office of the President of the United States of America in Presidential Policy Directive Order 21. Current research now focuses on securing and improving the management and efficiency of Industrial Control Systems (ICS). IIoT promises a solution in enhancement of efficiency in ICS. However, the presence of IIoT …


Portable Electrochemical System For Flexible Hybrid Electronics, Anthony Joseph Hanson Dec 2019

Portable Electrochemical System For Flexible Hybrid Electronics, Anthony Joseph Hanson

Masters Theses

This work focuses on the fabrication and design of a portable electrochemical sensing system for flexible hybrid electronic (FHE) sensors. A three-electrode chemical sensor was fabricated using copper tape on polyethylene terephthalate (PET) substrate, using laser etching process. An electronic circuit was designed to measure the sensor response through electrochemical techniques to detect different concentrations of glucose. The device was calibrated to give the user a concentration value in 5 seconds. The system was also designed to preform tests such as cyclic voltammogram and chronoamperogram for various chemicals. A Bluetooth Low Energy module was used to wirelessly transmit the results …


Behavior Of Hollow-Core Composite Bridge Columns Having Slender Inner Steel Tubes, Mohanad M. Abdulazeez, Mohamed Elgawady Dec 2019

Behavior Of Hollow-Core Composite Bridge Columns Having Slender Inner Steel Tubes, Mohanad M. Abdulazeez, Mohamed Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper experimentally investigates the seismic behavior of three large-scale hollow-core fiber-reinforced polymer-concrete-steel (HC-FCS) columns. An HC-FCS column consisted of a concrete shell sandwiched between an outer glass fiber-reinforced polymer (GFRP) tube and an inner steel tube. Both tubes provided continuous confinement for the concrete shell along with the height of the column. The columns had two different steel tube diameter-to-thickness (Ds/ts) ratios of 85, and 254. Each steel tube was embedded into the footing, with an embedded length of 1.25-1.6 times its diameter, while the GFRP tube was not embedded into the footing. Two columns were tested as as-built …


Extending The Capabilities Of Von Neumann With A Dataflow Sub-Isa, Martin Cowley Dec 2019

Extending The Capabilities Of Von Neumann With A Dataflow Sub-Isa, Martin Cowley

Masters Theses

Instruction set architectures (ISAs) such as x86, ARM, and RISC-V follow the control flow model of computation, where a program is defined as a sequence of instructions. Early processors executed instructions one-by-one based on the control flow of a program. Dataflow is an alternative model of computation that uses the availability of data to drive instruction execution. Any instruction can be chosen for execution, independent of the instruction order, as long as the data is available for that instruction. While modern processors incorporate concepts of the dataflow model in the microarchitecture, the implementation of the ISA, the amount of instruction …


Estimation Of The Fatigue Life Of Additively Manufactured Metallic Components Using Modified Strain Life Parameters Based On Surface Roughness, Peter Grohs Dec 2019

Estimation Of The Fatigue Life Of Additively Manufactured Metallic Components Using Modified Strain Life Parameters Based On Surface Roughness, Peter Grohs

Masters Theses

In this study, a method is developed to estimate the effects of surface roughness on the fatigue life of additively manufactured titanium Ti6Al4V, aluminum 7075–T6, and steel 4340 alloys through modified strain life parameters using finite element analysis (FEA). This method is highly beneficial to the fatigue analysis of as-built additively manufactured metal components, which possess rough surfaces that reduce fatigue life significantly but are challenging to analyze directly using finite element simulation because of complex geometries, i.e., modeling an exact surface profile is arduous.

An effective stress concentration factor, incorporating roughness data, is defined to quantify their effects on …


Intracellular Electrometer, Lucas M. Essenburg Dec 2019

Intracellular Electrometer, Lucas M. Essenburg

Masters Theses

The Western Michigan University Neurobiology Engineering Laboratory conducts re- search in energy-efficient electrical stimulation of biological neurons. Experimental work re- quires an intracellular electrometer to inject nanoamp-level currents into a biological neuron and to measure its membrane voltage response. In order to fully understand the generation of such minute currents, an `in-house' electrometer was designed, constructed, and validated. This required exploration of various design trade-offs including precision of generated nanoamp-level currents vs. susceptibility to noise, portability vs. functionality, and cost vs. functionality. The electrometer was successfully used to stimulate and measure responses of neurons from the medicinal leech Hirudo verbana …


Production And Purification Of Basic Fibroblast Growth Factor Fused To Two Collagen Binding Domains Expressed In E. Coli Bl21 Using Flask And Fed-Batch, Hazim Aljewari Dec 2019

Production And Purification Of Basic Fibroblast Growth Factor Fused To Two Collagen Binding Domains Expressed In E. Coli Bl21 Using Flask And Fed-Batch, Hazim Aljewari

Graduate Theses and Dissertations

Delivering effective and non-toxic doses of bioactive materials that can aid in activating tissue regeneration to wounded tissue has proven to be an enormous challenge. This study was designed to produce a potential therapeutic recombinant protein by fusing two collagen binding domains to basic fibroblast growth factors (bFGF) through a collagenase cleavage site linker, so it can release the bFGF in a wound site by the action of this enzyme. The novel fusion protein was expressed in Escherichia coli BL-21 (E. coli) using traditional flask shaker and fed-batch cultivation. Cell lysate was purified by FPLC using Immobilized metal affinity chromatography …


Microwave-Assisted And One-Step Synthesis Of Peg Passivated Fluorescent Carbon Dots From Gelatin As An Efficient Nanocarrier For Methotrexate Delivery, Nasser Arsalani, Parinaz Nezhad-Mokhtari, Esmaiel Jabbari Dec 2019

Microwave-Assisted And One-Step Synthesis Of Peg Passivated Fluorescent Carbon Dots From Gelatin As An Efficient Nanocarrier For Methotrexate Delivery, Nasser Arsalani, Parinaz Nezhad-Mokhtari, Esmaiel Jabbari

Faculty Publications

A green and simple process for preparing the polyethylene glycol passivated fluorescent carbon dots (CDs-PEG) have been studied by a microwave pyrolysis method, using gelatin and PEG as starting materials. This method is very effective for development of carbon-based quantum dots from gelatin with high quantum yield (QY). The synthesized CDs-PEG were found to emit blue photoluminescence (PL) with a maximum QY of 34%. At the following research, we investigated the effect of the presence of PEG on PL intensity, and the result showed that CDs-PEG becomes stronger PL properties than pure CDs from gelatin. The synthesized CDs-PEG were characterized …


Bioresorbable Composite Stents For Enhanced Response Of Vascular Smooth Muscle Cells, Hozhabr Mozafari Dec 2019

Bioresorbable Composite Stents For Enhanced Response Of Vascular Smooth Muscle Cells, Hozhabr Mozafari

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Formation of arterial plaque and stenosis is one of the main cardiovascular disease risk factors. Stenting is a popular approach to increase the inner diameter of the artery and provide an acceptable lumen gain. This is achieved by applying internal pressure to the arterial wall. Despite the desirable outcomes of this procedure, there are complexities and challenges that are being discussed among scholars in this area. Restenosis is one of these complications, in which smooth muscles cell start proliferation and remodeling in response of induced mechanical stresses. Another important issue is the placement of the stent and possible migration due …


Image Classification Using Fuzzy Fca, Niruktha Roy Gotoor Dec 2019

Image Classification Using Fuzzy Fca, Niruktha Roy Gotoor

School of Computing: Dissertations, Theses, and Student Research

Formal concept analysis (FCA) is a mathematical theory based on lattice and order theory used for data analysis and knowledge representation. It has been used in various domains such as data mining, machine learning, semantic web, Sciences, for the purpose of data analysis and Ontology over the last few decades. Various extensions of FCA are being researched to expand it's scope over more departments. In this thesis,we review the theory of Formal Concept Analysis (FCA) and its extension Fuzzy FCA. Many studies to use FCA in data mining and text learning have been pursued. We extend these studies to include …


Environmental Sustainability Assessment Of Small Nebraska Mechanical Water Resource Recovery Facilities: Impacts Of Construction And Operations, Sussan Moussavi Dec 2019

Environmental Sustainability Assessment Of Small Nebraska Mechanical Water Resource Recovery Facilities: Impacts Of Construction And Operations, Sussan Moussavi

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Many small, rural communities struggle with aging or inadequate water resource recovery facilities (WRRFs), and face challenges in constructing and operating such systems. Although existing literature has provided insight into the environmental sustainability of large systems including both the construction and operational phases, these studies have not examined small systems in adequate depth or breadth. The environmental impacts associated with construction may be notable for small WRRFs since the initial construction can be a larger share of the total life cycle environmental impact.

The goal of this work is to provide the environmental sustainability profiles of 12 mechanical WRRFs in …


Domain Adaptation In Unmanned Aerial Vehicles Landing Using Reinforcement Learning, Pedro Lucas Franca Albuquerque Dec 2019

Domain Adaptation In Unmanned Aerial Vehicles Landing Using Reinforcement Learning, Pedro Lucas Franca Albuquerque

School of Computing: Dissertations, Theses, and Student Research

Landing an unmanned aerial vehicle (UAV) on a moving platform is a challenging task that often requires exact models of the UAV dynamics, platform characteristics, and environmental conditions. In this thesis, we present and investigate three different machine learning approaches with varying levels of domain knowledge: dynamics randomization, universal policy with system identification, and reinforcement learning with no parameter variation. We first train the policies in simulation, then perform experiments both in simulation, making variations of the system dynamics with wind and friction coefficient, then perform experiments in a real robot system with wind variation. We initially expected that providing …


Synergistic Effect Of Nanocoatings For Corrosion And Wear Protection Of Steel Surfaces, Jaime Taha-Tijerina, Laura Peña Parás, Antonio Sánchez Fernández, Demófilo Maldonado Cortés, Pablo Sarmiento Barbosa, Jesús Rolando Adán López Dec 2019

Synergistic Effect Of Nanocoatings For Corrosion And Wear Protection Of Steel Surfaces, Jaime Taha-Tijerina, Laura Peña Parás, Antonio Sánchez Fernández, Demófilo Maldonado Cortés, Pablo Sarmiento Barbosa, Jesús Rolando Adán López

Informatics and Engineering Systems Faculty Publications

The purpose of this paper is to evaluate the corrosion and wear protection of a steel substrate by epoxy vinyl ester nanocomposite coatings with Zn and TiO2 nanoparticle fillers. Steel substrates were coated with epoxy vinyl ester nanocomposites, varying Zn and TiO2 nanofiller concentrations and combinations of both nanoparticles. Corrosion resistance was evaluated by salt spray fog test during 480 h, according to ASTM B-117. The degree of damage was obtained quantitatively by measuring the enhancement in corroded area compared to the scribe mark. Tribological evaluation was performed with a ball-on-disk tribotester, according to ASTM G-99. Results showed that the …


Machine Learning Applications To Predict Road Crash And Soccer Game Outcomes, Lu Bai Dec 2019

Machine Learning Applications To Predict Road Crash And Soccer Game Outcomes, Lu Bai

Master's Theses

Machine learning has become a cutting-edge and widely studied data science field of study in recent years across many industries and disciplines. In this thesis, two problems (1- crash severity prediction, 2- soccer game outcome prediction.) were investigated by using a set of machine learning approaches, namely: Ridge regression, Lasso Regression, Support Vector Machine (SVM), Neural Network (NN), Random Forest (RF).

The first study is focused on investigating the critical factors affecting crash severity on a comprehensive time-series state-wide traffic crash data. The dataset covers crashes occurred in the state of Connecticut between 1995 and 2014. Traffic crashes are an …


Measurement Of Polishing Rate As A Function Of Pad-Independent Abrasive Friction For Chemical Mechanical Polishing, Christopher Mcgowan Dec 2019

Measurement Of Polishing Rate As A Function Of Pad-Independent Abrasive Friction For Chemical Mechanical Polishing, Christopher Mcgowan

Master's Theses

As features on integrated circuits continue to grow smaller, they become more susceptible to damage from sequential planarization steps during fabrication. As planarization (known as chemical mechanical planarization, or simply CMP) is preformed multiple times and on every stage of fabrication, potential damage from it represents a significant financial risk, motivating a more fundamental understanding of the material removal process. CMP typically consists of a stiff polymer pad being used to bring a chemically active colloidal suspension of nanoscale particles into contact and relative motion with the substrate to be polished. For narrow sets of conditions, CMP is typically seen …


Corrosion Of Ecaped Magnesium Alloys And Its Background: A Review, G Manjunath Naik, N Sannayellappa, S Selvin Satheesh Kumar Dec 2019

Corrosion Of Ecaped Magnesium Alloys And Its Background: A Review, G Manjunath Naik, N Sannayellappa, S Selvin Satheesh Kumar

Journal of Metals, Materials and Minerals

The aim of this review article is to provide a brief mechanistic overview of magnesium alloys, equal channel angular pressing and corrosion behavior of un-ECAPed and ECAPed Mg alloys. The considerate of the corrosion processes of ECAPed Mg alloys builds upon interpretation of the corrosion of fine-grain magnesium alloys. This provides an understanding of the effect of grain size on corrosion of Mg alloys. This deep understanding is essential as a foundation if we are to produce corrosion-resistant magnesium alloys. Considerable has previously been accomplished, but there is enormous scope for development. This present concise review can provide a foundation …


Corrosion Behaviors Of Ship Structural Steel In Simulated Marine Tidal Environment, N Jaiyos, E Viyanit, P Mungsantisuk, K Sirivedin Dec 2019

Corrosion Behaviors Of Ship Structural Steel In Simulated Marine Tidal Environment, N Jaiyos, E Viyanit, P Mungsantisuk, K Sirivedin

Journal of Metals, Materials and Minerals

The tidal zone is severe marine environment for steel structures due to its wet-dry cyclic corrosion pattern. Regarding a specific application for inner ship hull, ship structural steel is always prone to corrosion dealing with three marine environments, including atmospheric, tidal, and immersion zones. Therefore, the current study aimed to investigate corrosion behaviors of two commercial ship structural steels, i.e. alloys A and B, which were exposed to simulated marine tidal environment. The effects of specimen arrangements designated as the isolated short-scale and vertical long-scale specimens were also determined. Based on weight loss determination, it revealed that the corrosion rates …


Effect Of Post Weld Heat Treatment Soaking Time On Microstructure And Mechanical Properties Of Tig Welded Grade 91 Steel, K Mithun, K Saraswathamma, D K. Verma Dec 2019

Effect Of Post Weld Heat Treatment Soaking Time On Microstructure And Mechanical Properties Of Tig Welded Grade 91 Steel, K Mithun, K Saraswathamma, D K. Verma

Journal of Metals, Materials and Minerals

Development of new alloy materials is in progress to improve thermal efficiency of supercritical boilers. One of such material is modified 9Cr-1Mo (Grade 91) martensitic alloy steel referred as T/P91. This material is extensively used in high temperature applications such as fabrication of superheater, reheater and economizer sections of a boiler. The present study is made to find the effect of post weld heat treatment (PWHT) soaking time on microstructure and mechanical properties of TIG welded ASTM A213 Grade 91 steel plate. Experiments were conducted for PWHT at 760°C for different soaking time such as 2, 4 and 6 hours …


Synthesis And Luminescence Properties Of Camoo4:Sm3+ Phosphors For Orange Photonic Materials, N Luewarasirikul, J Kaewkhao, H Kim Dec 2019

Synthesis And Luminescence Properties Of Camoo4:Sm3+ Phosphors For Orange Photonic Materials, N Luewarasirikul, J Kaewkhao, H Kim

Journal of Metals, Materials and Minerals

The series of CaMoO4 samples with different melting temperature (600, 700, 800 and 900°C) were synthesized in this work to investigate their phase structures by X-ray diffraction (XRD). The XRD result confirmed that the crystalline structures of the phosphors were obtained at 800°C (tetragonal structure with I41/a space group). Then, the series of Ca1-xMoO4:Smx (where x = 0.005, 0.010, 0.015, 0.020, 0.025 and 0.030) were prepared by solid-state reaction method to study their luminescence properties. The absorption spectra, recorded in UV, Vis and NIR regions, showed peaks at 405, 465, 952, 1096, 1252, 1405, 1513, 1573 and 1629 nm. The …


Physical And Strength Properties Of Fe/Sic Composites Under Microwave Hybrid Sintering Method, Sn A. Daud, S M. Tahir, M S. Anuar, Cn A. Jaafar, Mz M. Yusoff Dec 2019

Physical And Strength Properties Of Fe/Sic Composites Under Microwave Hybrid Sintering Method, Sn A. Daud, S M. Tahir, M S. Anuar, Cn A. Jaafar, Mz M. Yusoff

Journal of Metals, Materials and Minerals

Two different methods for the sintering of Fe/SiC composite prepared via uniaxial powder compaction are investigated in this work; the conventional furnace sintering and the microwave hybrid sintering methods. The important variables considered are the compositions of SiC in the Fe/SiC composite and the sintering temperatures used. The compositions of the SiC in the Fe/SiC used are 0, 10 and 20 wt. % and the sintering temperatures used are 1000°C, 1050°C, 1100°C and 1200°C. Damaged samples are obtained at the sintering temperatures of 1100°C and 1200°C for microwave hybrid method. For the undamaged samples obtained at 1000°C and 1050°C sintering …


Wood Plastic Composites Based On Recycled Poly(Ethylene Terephthalate) And Poly(Butylene Adipate-Co-Terephthalate), P Chaiwutthinan, A Pimpong, A Larpkasemsuk, S Chuayjuljit, A Boonmahitthisud Dec 2019

Wood Plastic Composites Based On Recycled Poly(Ethylene Terephthalate) And Poly(Butylene Adipate-Co-Terephthalate), P Chaiwutthinan, A Pimpong, A Larpkasemsuk, S Chuayjuljit, A Boonmahitthisud

Journal of Metals, Materials and Minerals

In this work, wood plastic composites (WPCs) were prepared from a selected recycled poly(ethylene terephthalate) (rPET)/poly(butylene adipate-co-terephthalate) (PBAT) blend ratio. The 70/30 (wt%/wt%) (rPET)/PBAT blend was incorporated with six loadings of wood flour (WF) (5 - 30 wt%) through melt mixing on a twin screw extruder, followed by injection molding. The mechanical properties of the WPCs, in terms of the impact, tensile and flexural strength, Young's modulus and elongation at break were determined as a function of the WF content. The results showed that the impact strength and elongation at break of the WPCs were all lower than those of …


The Use Of Reclaimed Rubber From Waste Tires For Production Of Dynamically Cured Natural Rubber/Reclaimed Rubber/Polypropylene Blends: Effect Of Reclaimed Rubber Loading, A Thitithammawong, C Hayichelaeh, W Nakason, N Jehvoh Dec 2019

The Use Of Reclaimed Rubber From Waste Tires For Production Of Dynamically Cured Natural Rubber/Reclaimed Rubber/Polypropylene Blends: Effect Of Reclaimed Rubber Loading, A Thitithammawong, C Hayichelaeh, W Nakason, N Jehvoh

Journal of Metals, Materials and Minerals

Reclaimed rubber (RR) from waste tires was introduced into thermoplastic vulcanizates (TPVs) based on blends of natural rubber (NR)/RR/polypropylene (PP). The curing characteristics of NR/RR compounds together with properties of TPVs, i.e., mixing and dynamic vulcanization behaviors and mechanical, dynamic and morphological properties, were investigated with respect to RR content. The results show that the RR affects static and dynamic vulcanization of rubber molecules by increasing cure rate but lowers curing efficiency. Increasing the RR content in NR/RR/PP TPVs slightly reduces tensile strength but with a sharp impact on elongation at break. Dynamic properties reveal that elastomeric response of NR/RR/PP …


One Step Pressing-Annealing To Produce Ltp Mnbi Magnets, T Charoensuk, A Tamman, P Jantaratana, S Abbasi, C Sirisathitkul Dec 2019

One Step Pressing-Annealing To Produce Ltp Mnbi Magnets, T Charoensuk, A Tamman, P Jantaratana, S Abbasi, C Sirisathitkul

Journal of Metals, Materials and Minerals

The production process for the high-purity low-temperature-phase (LTP) manganese bismuth (MnBi) magnets requires arc-melting, grinding and annealing materials under inert atmosphere. However, the formation of MnO is practically unavoidable during these steps since both Mn and MnBi are easily oxidized even by trace amounts of oxygen. In this work, an oxygen-free pressing-annealing system is developed to facilitate the synthesis of LTP MnBi with minimal oxidization. The semi-automatic pressing is carried out by using the compression piston and the load cell is used to measure the pressing force. The copper plate and cylindrical container are heated by nichrome filament heating. Mn …


Use Of Steam Explosion As A Green Alternative Method To Prepare Pulp From Pineapple Leaves, S Tanpichai, A Boonmahitthisud, S Witayakran Dec 2019

Use Of Steam Explosion As A Green Alternative Method To Prepare Pulp From Pineapple Leaves, S Tanpichai, A Boonmahitthisud, S Witayakran

Journal of Metals, Materials and Minerals

The use of agricultural wastes as an alternative form of the cellulosic material to wood has gained considerable attention due to the reduction of deforestation. After cultivation, a large number of pineapple leaves are considered as a waste. Here, the potential steam explosion process was used as a green alternative way to prepare pulp from pineapple leaves without any addition of the chemical treatments. The pineapple leaf fibers were defibrillated from fiber bundles due to the rapid depressurization with the steam pressure between 16 and 20 kgf·cm-2. The partly removal of hemicellulose and lignin associated with the increase of the …