Effects Of Milling Time On Sintering Properties And Formation Of Interface Al4c3 On Graphite Reinforced Al-4.5cu-1.5mg Nanocomposite,
2022
Chulalongkorn University
Effects Of Milling Time On Sintering Properties And Formation Of Interface Al4c3 On Graphite Reinforced Al-4.5cu-1.5mg Nanocomposite, Angga Khairul Fahmi, Haris Rudianto, Agus Sukarto Wismogroho, Wahyu Bambang Widayatno, Didik Aryanto, Bambang Hermanto
Journal of Metals, Materials and Minerals
Aluminum-based metal matrix nanocomposites have been extensively researched and developed for aerospace and automotive applications. Al-4.5Cu-1.5Mg with 0.5 wt% graphite were milled for 2 h, 4 h, 6 h, and 8 h using shaker mill under argon gas. The phenomena of deformation, fracturing, and cold welding during shaker mill were investigated to observe how the shaker mill effects on their morphology and formation of intermetallic phases due to its very high speed. Sintering under ultra-high purity argon gas for 99.9999% was done to produce high density materials. Intermetallic phase Al4C3 was found as a result reaction between aluminum and graphite …
Influence Of Six-Step Heat Treatment On Microstructures And Mechanical Properties Of 5160 Alloy Steel,
2022
Chulalongkorn University
Influence Of Six-Step Heat Treatment On Microstructures And Mechanical Properties Of 5160 Alloy Steel, Pattama Apichai
Journal of Metals, Materials and Minerals
AISI 5160 alloy steel grade with complete martensite structure to get the high-strength steel sheets quenched at 900 (Q1), 870 (Q2), 840 (Q3) and 810°C (Q4), respectively and temped at 780°C (Q5) and 680°C (Q6), respectively. The results show ferrite and pearlite microstructural appeared in as-sheet conditions. The strengthening rarely increased with increasing heat treatment steps, while the percentage elongation gradually decreased. The hardness change was secure with that of strengthening for the quenched martensite. In contrast, differences between the initial martensite hardness were no noticeable changes. The Q4 hardening involved the peak hardness and maximum ultimate tensile strength due …
Biodiesel Production From Waste Cooking Oil Using A New Heterogeneous Catalyst Sro Doped Cao Nanoparticles,
2022
Chulalongkorn University
Biodiesel Production From Waste Cooking Oil Using A New Heterogeneous Catalyst Sro Doped Cao Nanoparticles, Apisit Prokaewa, Siwaporn Meejoo Smith, Apanee Luengnaruemitchai, Mathi Kandiah, Supakorn Boonyuen
Journal of Metals, Materials and Minerals
Biodiesel production from waste palm cooking oil (WPCO) was studied. Calcium oxide with a strontium ion additive (Sr-CaO) was employed as a catalyst in transesterification reaction of used palm oil with methanol. The Sr-CaO was synthesized by co-precipitation method between SrCl2 and Ca(NO3)2, then calcined at 900°C for 5 h. The catalyst was characterized by using thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), Scanning electron microscope (SEM), and Fourier transform infrared spectrometer (FT-IR). The morphology and elements content of Sr and Ca in the catalyst were confirmed by SEM-EDX. The approximate catalyst diameter is 12.6±5.9 µm. The highest conversion was 99.33% …
Study Of The Effect Of Ph, Conditioning And Flotation Time On The Flotation Efficiency Of Phosphate Ores By A Soybean Oil Collector,
2022
Chulalongkorn University
Study Of The Effect Of Ph, Conditioning And Flotation Time On The Flotation Efficiency Of Phosphate Ores By A Soybean Oil Collector, Zohra Farid, Mohamed Abdennouri, Noureddine Barka, Youness Jannani, M'Hamed Sadiq
Journal of Metals, Materials and Minerals
The mid-low grade of phosphate ore, rich by the silicate and carbonate gangue minerals needs a special treatment using the flotation process. Where the collectors play a pivotal role. This study was conducted to enrich an untreated phosphate ore (without washing, desliming, hydrocycling, etc.), with an eco-friendly and economic collector based on soybean oil. Different analytical techniques such as UV-Visible, ATR-FTIR spectrometric and XRD were used in order to analyse and characterize the flotation products. The effects of the parameters, pulp pH, conditioning time and flotation time on gangue removal efficiency by flotation, were investigated. Flotation tests were applied for …
The Finished Polyester Fabric With Hot Nh4oh Pretreatment And Mixed Zno-Zn(Oh)2 Nanoparticles For Hydrophobic Property,
2022
Chulalongkorn University
The Finished Polyester Fabric With Hot Nh4oh Pretreatment And Mixed Zno-Zn(Oh)2 Nanoparticles For Hydrophobic Property, Samroeng Narakaew, Sittipong Au-Pree, Wipanoot Baison, Siwat Thungprasert, Itsariya Wattalo, Pranpreeya Jaipor, Theeraporn Promanan, Sukee Sukdee, Pakorn Santakij, Chainet Chanogkun, Kanjana Ruttanateerawichien, Aphiruk Chaisena, Pattama Apichai, Phiphop Narakaew
Journal of Metals, Materials and Minerals
This work aims to modify the hydrophobic coated polyester fabrics using 2%w/v ammonium hydroxide (NH4OH) at 90℃ prior and subsequently dipped in two difference aqueous zinc solution batchs containing 0.6%w/v zinc precursors with/without starch and NH4OH, finally dehydration, and characterized by the attenuated total reflection - Fourier transform Infrared (ATR-FTIR) and Raman spectroscopy (Raman), X-ray diffraction (XRD), Field emission scanning electron microscope (FE-SEM), Energy dipersive spectrometry (EDX), and Water contact angle (WCA) of 10 mL dropping at 23℃ and humidity of 63%. Raman spectra and XRD patterns results showed e-zinc hydroxide (e-Zn(OH)2), zinc oxide nanoparticle (ZnO NP) and ZnO-starch nanocomposite …
Epoxidized Natural Rubber/Silane Modified Silica Nanocomposites Prepared In Latex Stage,
2022
Chulalongkorn University
Epoxidized Natural Rubber/Silane Modified Silica Nanocomposites Prepared In Latex Stage, Supat Moolsin, Duangkamon Sawangkan
Journal of Metals, Materials and Minerals
Epoxidized natural rubber (ENR) was synthesized from natural rubber (NR) latex via in situ epoxidation using HCOOH and H2O2. The prepared ENR with 22 mol% epoxidation (ENR-22) was reinforced with silane modified silica (SMS) nanoparticles with different SMS loading in latex stage. The tensile properties, thermal stability, oil resistance and morphology of the ENR-22/SMS nanocomposites were investigated. The tensile strength was improved significantly and gained the maximum point at 7.5 phr SMS content. The thermogravimetric analysis showed an increased initial degradation temperature with the addition of SMS, suggesting higher thermal stability of the nanocomposites. The oil resistance of ENR-22/SMS nanocomposites …
Use Of Oil Palm Frond Waste To Reinforce Poly(Lactic Acid) Based Composites With The Improvement Of Interfacial Adhesion By Alkali Treatment,
2022
Chulalongkorn University
Use Of Oil Palm Frond Waste To Reinforce Poly(Lactic Acid) Based Composites With The Improvement Of Interfacial Adhesion By Alkali Treatment, Nattakarn Hongsriphan, Jidapa Subsanga, Pimpisa Suebsai, Sunisa Sitthipong, Pajaera Patanathabutr
Journal of Metals, Materials and Minerals
Oil palm frond waste was used as reinforcing fibers for biodegradable poly(lactic acid) or PLA in order to produce green composites that increased the value of agricultural waste. The alkali-treated oil palm frond (OPF) fibers of 30 wt% or 40 wt% were compounded with PLA and moulded into specimens. The alkali treatment was 0 wt%, 1 wt%, 3 wt%, and 5 wt% of the fibers for compatibility improvement with PLA matrix. It was found that the alkali-treated PLA/OPF composites adding 30 wt% and 40 wt% had the flexural modulus to be about 55% and 75% higher than those without the …
Design, Development And Characterization Of A Mid-Frequency (35 Khz) Tonpilz Transducer Array From 0.675pmn-0.325pt Piezoceramics,
2022
Chulalongkorn University
Design, Development And Characterization Of A Mid-Frequency (35 Khz) Tonpilz Transducer Array From 0.675pmn-0.325pt Piezoceramics, Merve Nur Çiftçi, Berk Değirmenci, Irem Böbrek, Sedat Alkoy, Aykut Aykaç, Muhammet Boz, Ayşe Berksoy-Yavuz, Ezgi Yalcin, Namik K. Gozuacik, Ebru Menşur
Journal of Metals, Materials and Minerals
A mid-frequency tonpilz transducer array was designed and analyzed by finite element method using commercial ATILA code and constructed using piezoceramic rings with lead magnesium niobate (PMN)-lead titanate (PT) composition. The morphotropic phase boundary (MPB) 0.675Pb(Mg1/3Nb2/3)O3-0.325PbTiO3 composition was chosen to obtain higher performance from the transducer due to the superior dielectric and electromechanical properties of the MPB compositions. A pure perovskite phase was obtained from the ceramics. Piezoelectric charge coefficient (d33) was measured as 435 pC×N-1. Single tonpilz element and an array consisting of 7-unit array were constructed and later potted in polyurethane for underwater measurements. A second array was …
Amino-Containing Polymer-Coated Magnetite Nanoparticles As Nano-Adsorbents For Bisphenol A: Synthesis, Kinetic And Thermodynamic Study,
2022
Chulalongkorn University
Amino-Containing Polymer-Coated Magnetite Nanoparticles As Nano-Adsorbents For Bisphenol A: Synthesis, Kinetic And Thermodynamic Study, Jakkrit Tummachote, Metha Rutnakornpituk, Duangdao Channei, Filip Kielar, Boonjira Rutnakornpituk
Journal of Metals, Materials and Minerals
Magnetite nanoparticles coated with poly(dimethyl aminoethyl methacrylate) (PDMAEMA@MNPs) and their quarternized form (PQDMAEMA@MNPs) were successfully synthesized and used as nano-adsorbents for bisphenol A (BPA). The particles were spherical with the average particle size between 10 and 20 nm in diameter with a moderate degree of nanoclustering (ca.150-200 particles/cluster). In terms of adsorption properties, the PDMAEMA@MNPs exhibited a higher BPA adsorption capacity (1.05 mg/g MNP at pH 9) than the quaternized form (0.50 mg/g MNP at pH 9). Equilibrium isotherm, kinetic, and thermodynamic characteristics of BPA adsorption on the PDMAEMA@MNPs were investigated. It was found that the BPA adsorption …
Elastic Properties Of Boro-Tellurite Glasses Doped With Europium Oxide,
2022
Chulalongkorn University
Elastic Properties Of Boro-Tellurite Glasses Doped With Europium Oxide, Chinnappareddy Devaraja, G. V. Jagadeesha Gowda, Bheemaiah Eraiah, G. K. Narasihma Murthy
Journal of Metals, Materials and Minerals
The glass series of xEu2O3-5PbO-25TeO2-(70-x) B2O3, where x=0.1 mol% to 0.6 mol% were prepared by employing the conventional melt quenching method. The non-crystallinity of prepared BTE glasses was examined by the X-ray diffraction method. The very important mechanical properties such as elastic moduli, Debye temperature, Poisson’s ratio, fractional bond connectivity, softening temperature, acoustic impedance, and the thermal expansion coefficient of the BTE glasses have been studied by measuring ultrasonic velocity. The experimental results indicate that the calculated parameters strongly depend on increasing Eu2O3 concentration. The elastic moduli of the prepared samples were found to decrease with Eu2O3 concentration and this …
Enhanced Photocatalytic Activity Of Zno Nanostructures Deposited On Mesh Through Electrochemical Deposition And Thermal Oxidation,
2022
Chulalongkorn University
Enhanced Photocatalytic Activity Of Zno Nanostructures Deposited On Mesh Through Electrochemical Deposition And Thermal Oxidation, Chantana Aiempanakit, Thongchai Phantaporn, Kamon Aiempanakit
Journal of Metals, Materials and Minerals
This article reported that the properties of zinc oxide (ZnO) nanostructures were modified by the thermal oxidation process at different temperatures in the range of 200℃ to 600℃ for 1 h. The Zn films were deposited on a stainless steel mesh by using the electrochemical deposition technique. The elemental composition of Zn and O was exhibited via energy-dispersed X-ray spectroscopy in which the atomic ratio of O/Zn increased with the increase of oxidation temperature. The results showed that oxidation temperature has a significant effect on the morphological and crystal structure. The nanosheet structure of the as-deposited film transferred to the …
Brazilein Modified Zinc Oxide Nanorods With Enhanced Visible Light-Responsive Photocatalytic Efficiency,
2022
Chulalongkorn University
Brazilein Modified Zinc Oxide Nanorods With Enhanced Visible Light-Responsive Photocatalytic Efficiency, Montri Aiempanakit, Penpicha Sudjai, Kittiyaporn Singsumphan, Sakchai Laksee, Cheewita Suwanchawalit
Journal of Metals, Materials and Minerals
Photocatalytic efficiency of ZnO nanorods has been investigated with respect to the concentration of brazilein. Brazilein modified ZnO nanorods were prepared by an impregnation process with 1.0%w/v, 2.5%w/v, and 5.0%w/v of brazilein solution. In order to correlate the variation in concentration distributions and photocatalytic performance, the phase composition, optical properties, and photo-catalytic activities of brazilein modified ZnO nanorods prepared with different brazilein concentrations have been investigated and compared to an unmodified ZnO nanorods. The photocatalytic properties were measured in terms of indigo carmine degradation under visible light irradiation. It was found that ZnO nanorods with the highest visible light-responsive photocatalytic …
Extraction Of Molybdenum From A Spent Hds Catalyst Using Alkali Leaching Reagent,
2022
Chulalongkorn University
Extraction Of Molybdenum From A Spent Hds Catalyst Using Alkali Leaching Reagent, Chatisa Kansomket, Piamsak Laokhen, Tanongsak Yingnakorn, Tapany Patcharawit, Sakhob Khumkoa
Journal of Metals, Materials and Minerals
This research investigated extraction of molybdenum from spent hydrodesulfurization (HDS) catalyst used in petroleum refinery. The spent HDS catalyst still however contains significant amounts of valuable metals such as molybdenum and nickel for example, thereby recovery of such metals are of great interest. Pyro-hydrometallurgical process was utilized in this research to selectively extract molybdenum from the spent HDS catalyst using alkali leaching reagent. The process start from calcination of spent HDS catalyst, alkali leaching using sodium carbonate, purification by carbon adsorption-desorption, precipitation of ammonium molybdate and finally calcination to give molybdenum trioxide (MoO3) as the final recycling product. Effects of …
Recovery Of Nickel From Spent Electroplating Solution By Hydrometallurgical And Electrometallurgical Process,
2022
Chulalongkorn University
Recovery Of Nickel From Spent Electroplating Solution By Hydrometallurgical And Electrometallurgical Process, Piamsak Laokhen, Natthicha Ma-Ud, Tanongsak Yingnakorn, Tapany Patcharawit, Sakhob Khumkoa
Journal of Metals, Materials and Minerals
Recovery of nickel from spent electro nickel plating solution has been investigated via hydro-metallurgical and electrometallurgical processes. Experimental consisted of 3 steps, including precipitation of nickel from spent solution, leaching of nickel precipitate, and electrowinning of nickel. Nickel precipitation was performed using sodium hydroxide. Leaching parameters such as 1 M to 3 M sulfuric acid concentration, 100 g×L-1 to 300 g×L-1 solid to liquid ratio, and 30 min to 180 min leaching time were investigated. The leachate from the optimal leaching condition was further used as an electrolyte in electrowinning process. Effects of 3.3 V to 3.7 V cell voltage …
Development Of Aggregate From Bottom Ash In Environmentally Friendly Concrete,
2022
Chulalongkorn University
Development Of Aggregate From Bottom Ash In Environmentally Friendly Concrete, Udomvit Chaisakulkiet, Nattapong Makaratat, Sumrerng Rukzon
Journal of Metals, Materials and Minerals
This research presents a study of bottom ash for using as fine and coarse aggregates in concrete, B-F and B-C, respectively. Results of compressive strength and durability of the concrete containing B-F and B-C aggregates were investigated. Normal fine and coarse aggregates were replaced with the B-F and B-C aggregates at 0, 25, 50, 75 and 100% by weight of the normal aggregates. The results showed that the compressive strengths of the concretes were increased when the B-F and B-C aggregates were used at replacement levels of 25% and 50%. The water absorption and chloride resistances of the concretes were …
Microscale Transverse Compression Modeling: A Comparative Study Of The Analytical Mac/Gmc Methods To Experimental Results,
2022
Michigan Technological University
Microscale Transverse Compression Modeling: A Comparative Study Of The Analytical Mac/Gmc Methods To Experimental Results, Emily Zeitunian
Dissertations, Master's Theses and Master's Reports
Composite materials require a multi-scale approach to fully understand its behavior. At the micro level, material behavior analysis is conducted most often using numerical or analytical approaches. These models, however, require validation from experimental data to ensure material predictions are accurate. This study compares a semi-analytical micromechanical analysis tool, MAC/GMC, to experimental results of in-situ microscale transverse compression testing conducted at AFRL facilities. Effective properties, stress-strain curves, stress and strain fields, and damage predictions are compared with experimental outputs. Both generalized method of cells (GMC) and high-fidelity generalized method of cells (HFGMC) theories implemented within MAC/GMC show results that agree …
Design And Analysis Of Marangoni-Driven Robotic Surfers,
2022
Michigan Technological University
Design And Analysis Of Marangoni-Driven Robotic Surfers, Mitchel L. Timm
Dissertations, Master's Theses and Master's Reports
We designed and experimentally studied the dynamics of two robotic systems that surf along the water-air interface. The robots were self-propelled by means of creating and maintaining a surface tension gradient resulting from an asymmetric release of isopropyl alcohol (IPA). The imbalance in the distribution of surface tension surrounding the robots generates a propulsive force commonly referred to as Marangoni propulsion. First, we considered a single surfer, which was custom-made with novel control mechanisms that allow for both forward motion and steering to be remotely adjusted solely through the manipulation of local surface stresses. We analyzed the performance of this …
Cold-Formed Steel Strength Predictions For Torsion,
2022
Old Dominion University
Cold-Formed Steel Strength Predictions For Torsion, Yu Xia, Robert S. Glauz, Benjamin W. Schafer, Michael Seek, Hannah B. Blum
Engineering Technology Faculty Publications
Locally slender open cross-section members are susceptible to significant twisting and high warping torsion stresses. Torsion considerations are complicated by whether it is derived as a first-order effect from loading or a second-order effect from instability. Previous direct torsion experiments on lipped channels have shown significant inelastic reserve in limited cases. The current design for combined bending and torsion interaction has some limitations, including only considering the first yield in torsion and ignoring the cross-section slenderness in torsion. A parametric study is conducted to predict the torsion capacity in locally slender cross-sections. Shell finite element models of lipped Cee and …
Exploring The Effects Of Chip Flexibility On The Behavior Of Standing Seam Diaphragms To Brace Cold Formed Steel Purlins,
2022
Old Dominion University
Exploring The Effects Of Chip Flexibility On The Behavior Of Standing Seam Diaphragms To Brace Cold Formed Steel Purlins, Michael W. Seek
Engineering Technology Faculty Publications
Cold-formed steel C- and Z-shaped purlins in standing seam roof systems rely on the diaphragm action provided by the panels to restrain lateral movements and thus increase the load carrying capacity the purlins. The clip connection between the purlin and the panel has inherent and sometimes intentional flexibility designed to accommodate thermal deformations. The lateral deformation behavior of standing seam systems supported by Zees is highly nonlinear and this behavior is not well understood. The flexibility has major implications on the transfer of diaphragm forces throughout these systems and simplified models often grossly overpredict the demands on the diaphragm and …
Lateral-Torsional Instability And Biaxial Bending Of Imperfect Frp I-Beams,
2022
Old Dominion University
Lateral-Torsional Instability And Biaxial Bending Of Imperfect Frp I-Beams, Jodi Knorowski, Stella B. Bondi, Zia Razzaq
Civil & Environmental Engineering Faculty Publications
This paper presents the outcome of a theoretical and experimental study of the behavior of Fiber Reinforced Polymer (FRP) I-beams exposed to lateral-torsional instability or when subjected to biaxial bending. Laboratory experiments involved the application of vertical and horizontal static loads to a 4 x 4 x ¼ in. I-beam with various lengths and the resulting deflections were recorded. Governing biaxial flexure and torsion differential equations were modified to account for the presence of initial imperfections and subsequently solved using a central finite-difference scheme. The theoretical predictions of the beam behavior were found to be in good agreement with what …
