Synthesis And Luminescence Properties Of Camoo4:Sm3+ Phosphors For Orange Photonic Materials,
2019
Chulalongkorn University
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,
2019
Chulalongkorn University
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),
2019
Chulalongkorn University
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,
2019
Chulalongkorn University
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,
2019
Chulalongkorn University
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,
2019
Chulalongkorn University
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 …
Characterization Of Zirconium Oxides Part I: Raman Mapping And Spectral Feature Analysis,
2019
Boise State University
Characterization Of Zirconium Oxides Part I: Raman Mapping And Spectral Feature Analysis, Corey M. Efaw, Jordan L. Vandegrift, Michael Reynolds, Samuel Mcmurdie, Brian J. Jaques, Hui Xiong, Michael F. Hurley
Materials Science and Engineering Faculty Publications and Presentations
Raman mapping of sectioned zirconium cladding oxides was performed to analyze different spectral features before and after breakaway, as well as between zirconium and its alloys Zr-2.65Nb, Zry-3, and Zry-4. Oxide phase composition, or percent tetragonality, was defined to compare tetragonal to monoclinic zirconia. Percent tetragonality was spatially mapped to support distinction of zirconia phase distribution. A tetragonal-rich layer was seen at the metal/oxide interface, while post-breakaway samples exhibited increased amount of tetragonal phase in the bulk of their oxides. Spatial mapping of spectral peak location and half-width at half-maximum was accomplished to distinguish differences in stability mechanisms of tetragonal-rich …
Bioresorbable Composite Stents For Enhanced Response Of Vascular Smooth Muscle Cells,
2019
University of Nebraska-Lincoln
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 …
Extending Mission Duration Of Uas Multicopters: Multi-Disciplinary Approach,
2019
University of Nebraska-Lincoln
Extending Mission Duration Of Uas Multicopters: Multi-Disciplinary Approach, Marc Lussier
Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research
Multicopters are important tools in industry, the military, and research but suffer from short flight times and mission durations. In this thesis, we discuss three different ways to increase flight times and therefore increase the viability of using multicopters in a variety of missions. Alternate fuel sources such as hydrogen fuel and solar cells are starting to be used on multicopters, in our research we simulate modern fuel cells and show how well they currently work as the power source for multicopters and how close they are to becoming useful in Unmanned Aircraft System (UAS) technology. Increasing the efficiency in …
Development Of A Mix Design Adjustment Method For Fiber Reinforced Concrete And Super High Performance Concrete Based On Excess Paste,
2019
University of Nebraska-Lincoln
Development Of A Mix Design Adjustment Method For Fiber Reinforced Concrete And Super High Performance Concrete Based On Excess Paste, Joe Malloy
Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research
The main objective of this study was to develop a mix design adjustment method for Fiber Reinforced Concrete (FRC) that would maintain appropriate workability while improving hardened concrete performance. A literature review was conducted to examine existing methods for adjusting mix designs to account for fiber introduction. It was found that while increasing fine aggregate and cement paste content can make up for lost workability with the addition of fibers, no rational mix design adjustment method is available. Reference mix designs from the Nevada Department of Transportation and the Nebraska Department of Transportation were used, and this study focused on …
Accelerated Relaxation In Disordered Solids Under Cyclic Loading With Alternating Shear Orientation,
2019
Wright State University - Main Campus
Accelerated Relaxation In Disordered Solids Under Cyclic Loading With Alternating Shear Orientation, Nikolai V. Priezjev
Mechanical and Materials Engineering Faculty Publications
The effect of alternating shear orientation during cyclic loading on the relaxation dynamics in disordered solids is examined using molecular dynamics simulations. The model glass was initially prepared by rapid cooling from the liquid state and then subjected to cyclic shear along a single plane or periodically alternated in two or three dimensions. We showed that with increasing strain amplitude in the elastic range, the system is relocated to deeper energy minima. Remarkably, it was found that each additional alternation of the shear orientation in the deformation protocol brings the glass to lower energy states. The results of mechanical tests …
Nanoscale Optical And Correlative Microscopies For Quantitative Characterization Of Dna Nanostructures,
2019
Boise State University
Nanoscale Optical And Correlative Microscopies For Quantitative Characterization Of Dna Nanostructures, Christopher Michael Green
Boise State University Theses and Dissertations
Methods to engineer nanomaterials and devices with uniquely tailored properties are highly sought after in fields such as manufacturing, medicine, energy, and the environment. The macromolecule deoxyribonucleic acid (DNA) enables programmable self-assembly of nanostructures with near arbitrary shape and size and with unprecedented precision and accuracy. Additionally, DNA can be chemically modified to attach molecules and nanoparticles, providing a means to organize active materials into devices with unique or enhanced properties. One particularly powerful form of DNA-based self-assembly, DNA origami, provides robust structures with the potential for nanometer-scale resolution of addressable sites. DNA origami are assembled from one large DNA …
Ultrasonic Wave Propagation In Copper/Graphene Metal Matrix Composites,
2019
University of Arkansas, Fayetteville
Ultrasonic Wave Propagation In Copper/Graphene Metal Matrix Composites, Casey Lindbloom
Mechanical Engineering Undergraduate Honors Theses
Emerging metallic composite materials implanted with graphene sheets are showing immense promise, with benefits being observed with regards to mechanical, thermal, and electrical material properties. This research aims to investigate the effects on ultrasonic wave propagation in Copper/Graphene Metal Matrix Composites (Cu/Gr MMCs) with varying graphene arrangements inspired from nacre and bone nanoscale material distributions. To accomplish this, the molecular dynamics (MD) method is utilized to simulate nanoscale wave propagation on a set of Cu/Gr MMCs with differing graphene arrangements and volume percentages ranging up to 4.56%. The computational model results are then analyzed to determine the variation in energy …
Mandela Splash Pad Pre-Construction Plan,
2019
University of Nebraska at Omaha
Mandela Splash Pad Pre-Construction Plan, Levi Sandbulte
Theses/Capstones/Creative Projects
In the construction industry, it is the responsibility of the general contractor to take the architect’s ideas and turn it into a real building. Many times this requires ample communication and several drafts. This efficient execution of this process is vital to the completion of a successful project. In this project, I practice this communication process. The challenge presented by the owner is to build an affordable splash pad, and without impacting the construction schedule of the Early Childhood Development Center (ECDC) that is being built on the same property at the same time. This proposal gives the owner a …
Modification Of Optical And Structural Properties Of Dc Magnetron Sputtered Tungsten Oxide Thin Films For Electrochromic Application,
2019
Chulalongkorn University
Modification Of Optical And Structural Properties Of Dc Magnetron Sputtered Tungsten Oxide Thin Films For Electrochromic Application, P Yaemsanguansak, M Sittishoktram, R Tuayjaroen, E Ketsombun, T Lertvanithphol, C Luangchaisri, T Jutarosaga
Journal of Metals, Materials and Minerals
The optical properties of tungsten oxide thin films prepared by a reactive DC magnetron sputtering technique were investigated. The influences of O2 flow rates (15 and 18 sccm) and DC sputtering powers (5, 15 and 25 W) on the optical properties of 200 nm-thick tungsten oxide films on indium tin oxide substrates (WO3/ITO/glass) were investigated using UV-visible spectrophotometer. The results indicated that the transmission modulation in visible region between colored state and bleached state of the films increased significantly with decreasing DC sputtering power and increasing O2 flow rate. The results corresponded with the increase of film roughness and density …
Effects Of Magnetic Domain And Twin Boundary Interactions On Magneto-Mechanical Properties Of Magnetic Shape Memory Alloys,
2019
Boise State University
Effects Of Magnetic Domain And Twin Boundary Interactions On Magneto-Mechanical Properties Of Magnetic Shape Memory Alloys, Medha Veligatla
Boise State University Theses and Dissertations
Magnetic shape memory (MSM) alloys deform substantially when exposed to a magnetic field. This recoverable plastic deformation occurs through crystallographic twinning. Thereby the internal magnetic domain structure modulates the deformation mechanisms through the interaction of magnetic domains with twin boundaries. We study the meso scale magneto-structural interactions that affect the macroscopic material properties of MSM alloys. The study at the meso length scale is most effective as it allows for resolving interactions at magnetic domain wall width resolution with reasonable computing cost. We apply micromagnetics simulations to evaluate the evolution of magnetic domains, their interaction with twin boundaries, the distribution …
Publisher Correction: Pore Elimination Mechanisms During 3d Printing Of Metals (Nature Communications, (2019), 10, 1, (3088), 10.1038/S41467-019-10973-9),
2019
Missouri University of Science and Technology
Publisher Correction: Pore Elimination Mechanisms During 3d Printing Of Metals (Nature Communications, (2019), 10, 1, (3088), 10.1038/S41467-019-10973-9), S. Mohammad H. Hojjatzadeh, Niranjan D. Parab, Wentao Yan, Qilin Guo, Lianghua Xiong, Cang Zhao, Mimglei Qu, Luis I. Escano, Xianghui Xiao, Kamel Fezzaa, Wes Everhart, Tao Sun, Lianyi Chen
Mechanical and Aerospace Engineering Faculty Research & Creative Works
The original version of this Article contained an error in Fig. 4. The x-axis labels in Fig. 4a, b were incorrectly labelled 'Diameter (mm)', rather than the correct 'Diameter (µm)'. This has been corrected in both the PDF and HTML versions of the Article.
Machine Learning Predictions Electronic Couplings For Charge Transport Calculations Of P3ht,
2019
Boise State University
Machine Learning Predictions Electronic Couplings For Charge Transport Calculations Of P3ht, Evan D. Miller, Matthew L. Jones, Mike M. Henry, Bryan Stanfill, Eric Jankowski
Materials Science and Engineering Faculty Publications and Presentations
The purpose of this work is to lower the computational cost of predicting charge mobilities in organic semiconductors, which will benefit the screening of candidates for inexpensive solar power generation. We characterize efforts to minimize the number of expensive quantum chemical calculations we perform by training machines to predict electronic couplings between monomers of poly-(3-hexylthiophene). We test five machine learning techniques and identify random forests as the most accurate, information-dense, and easy-to-implement approach for this problem, achieving mean-absolute-error of 0.02 [× 1.6 × 10−19 J], R2 = 0.986, predicting electronic couplings 390 times faster than quantum chemical calculations, …
Oxidation Behavior Of Welded Zry-3, Zry-4, And Zr–1nb Tubes,
2019
Boise State University
Oxidation Behavior Of Welded Zry-3, Zry-4, And Zr–1nb Tubes, Jordan Vandegrift, Clemente J. Parga, Ben Coryell, Darryl P. Butt, Brian J. Jaques
Materials Science and Engineering Faculty Publications and Presentations
The Transient Reactor Test (TREAT) facility is a research reactor designed to simulate rapid transients to test new fuel designs. TREAT's cladding is exposed to unique conditions compared to normal water reactors. These conditions include: exposure to air at high temperatures (≥600 °C), rapid heating (≈700 °C/s), and cladding geometry that includes chamfers and welds. This work investigates the effects of chamfering and welding on the oxidation behavior of zirconium alloys (Zircaloy-3, Zircaloy-4, and Zr–1Nb). Tube specimens were examined under isothermal and transient conditions in dry and humid air. The effect of weld type (tungsten inert …
Piezoceramic-Polymer And Piezoceramic-Cement Composites: A Brief Review,
2019
Chulalongkorn University
Piezoceramic-Polymer And Piezoceramic-Cement Composites: A Brief Review, S Inthong, S Eitssayeam, J Tontrakoon, T Tunkasiri
Journal of Metals, Materials and Minerals
The physical properties of piezoceramic-polymers and lead-based or lead-free - Portland cement or geopolymer are described as part of this brief review. The connectivities such as 0-3, 1-3, 2-2 and 3-3 were employed to fabricate the composites. Their physical properties such as dielectric, coupling constant, acoustic impedance etc. were measured. The acoustic impedance obtained from the PZT-epoxy resin (0-3/1-3 connectivity) showed quite low. This can be further developed to match with water or human tissue for both hydrophone and medical applications. The properties of the composites containing leadbased or lead-free cement or geopolymer were also revealed. The results prove that …
