Development Of Reduced Chemical Kinetic Models For The Numerical Simulation Of Combustion And Emissions Behavior Of Representative Conventional And Bio-Derived Fuels,
2020
California State University, Fresno
Development Of Reduced Chemical Kinetic Models For The Numerical Simulation Of Combustion And Emissions Behavior Of Representative Conventional And Bio-Derived Fuels, Mazen A. Eldeeb
Mineta Transportation Institute
The study addresses two of the main challenges facing combustion modeling for transportation fuels: simultaneous simulation of non-related combustion problems and reducing the computational cost of the modeling process itself. To address the first challenge, researchers determine a characteristic flame time from thermal diffusivity and laminar burning velocity. Researchers examine parametric dependence of flame time and ignition delay time on pressure, temperature and equivalence ratio for methane, based on validated chemical kinetic mechanisms. The study reveals flame time and ignition delay time show similar temperature dependence, flame time has stronger dependence on equivalence ratio and weaker dependence on pressure than …
Fabrication Of Magnetocaloric La(Fe,Si)13 Thick Films,
2020
Université Grenoble Alpes
Fabrication Of Magnetocaloric La(Fe,Si)13 Thick Films, N H. Dung, N B. Doan, P De Rango, L Ranno, Karl G. Sandeman, N M. Dempsey
Publications and Research
La(Fe,Si)13–based compounds are considered to be very promising magnetocaloric materials for magnetic refrigeration applications. Many studies have focused on this material family but only in bulk form. In this paper we report on the fabrication of thick films of La(Fe,Si)13, both with and without post-hydriding. These films exhibit magnetic and structural properties comparable to bulk materials. We also observe that the ferromagnetic phase transition has a negative thermal hysteresis, a phenomenon not previously found in this material but which may have its origins in the availability of a strain energy reservoir, as in the cases of …
Tribological Properties Of Polymeric Composites: A Review,
2020
Chulalongkorn University
Tribological Properties Of Polymeric Composites: A Review, Yusuf Şahin, Hakan Şahin
Journal of Metals, Materials and Minerals
Tribology deals with interacting surfaces in sliding, rolling or any others types of motions, which is much importance in designing for machine components to improve their durability's of mechanical engineering systems. This study overviews the most recent studies on the tribological behavior of polymeric based materials containing different fillers. Some microstructural and mechanical properties of the epoxy composite are introduced. In addition, mechanisms of increasing wear resistance and reducing friction coefficient for polymeric composites are reviewed. An overview is also covered the process optimization for the dry wear results of polymeric composites using Taguchi Method (TM) and Response Surface Method …
Ceramic And Glass-Ceramic Fillers In Dental Composites: A Review,
2020
Chulalongkorn University
Ceramic And Glass-Ceramic Fillers In Dental Composites: A Review, Sumana Ghosh
Journal of Metals, Materials and Minerals
Dental composite fillings are most popular fillings wherein various fillers have been suitably dispersed in a polymerizable resin. Major challenges are to make choice of suitable filler and their distribution in the resin matrix in the development of the dental fillings. Apart from traditional fillers ceramic whiskers, glass fibres, branched fibres and nanoporous powders have also been investigated as fillers in dental composites. Recently, ceramic, and glass-ceramic fillers are attracting attention of the researchers due to their suitable combination of material properties. In the current paper, the prospect of ceramic and glass-ceramics as fillers in fabricating dental composites has been …
Insearchfornear-Room-Temperaturesuperconductingcriticaltemperatureofmetalsuperhydridesunderhighpressure: A Review,
2020
Chulalongkorn University
Insearchfornear-Room-Temperaturesuperconductingcriticaltemperatureofmetalsuperhydridesunderhighpressure: A Review, Udomsilp Pinsook
Journal of Metals, Materials and Minerals
An overview and the latest status of the superconductivity of metal superhydrides under high pressure are discussed in this review article. The searching for near-room-temperature superconductors have been one of the most enthusiastic fields in physics. This is because of several key factors in both theoretical and experimental sides. By advanced experiment innovation, pressure exceeded that of the earth's core can be generated in laboratories. This allows scientists to explore new physics of materials under high pressure. In the synergy form, the theoretical calculation gives accountable predictions on the structural and electronic properties which can be served as a practical …
Synthesis And Characterization Of Ball-Milled Eggshell And Al2o3 Reinforced Hybrid Green Composite Material,
2020
Chulalongkorn University
Synthesis And Characterization Of Ball-Milled Eggshell And Al2o3 Reinforced Hybrid Green Composite Material, Shrawan Kumar, Shashi Prakash Dwivedi, Vijay Kumar Dwived
Journal of Metals, Materials and Minerals
Eggshell is a by-product (a secondary product derived from a production process) which produces lots of environment pollution. However, some environment pollution can be reduced by utilizing this waste. In the present investigation, an attempt was made to utilize eggshell as the reinforcement material with alumina (Al2O3) in the development of composite material. Carbonized eggshell particles and Al2O3 ceramic particles were ball-milled up to 100 hours to obtain a uniform particle size of reinforcement particles. Results showed that by using Al2O3 with eggshell in the development of aluminium based composite material after the ball-milling, mechanical properties were significantly improved. However, …
Production Of Silica-Based Ceramics Sintered Under Nitrogen Atmosphere From Rice Husk And Sugarcane Bagasse Ash,
2020
Chulalongkorn University
Production Of Silica-Based Ceramics Sintered Under Nitrogen Atmosphere From Rice Husk And Sugarcane Bagasse Ash, Wiphawan Khopthong, Benya Cherdhirunkorn
Journal of Metals, Materials and Minerals
Nitride silica-based ceramics were prepared by sintering under nitrogen atmosphere using rice husk ash and bagasse ash as raw materials. X-ray Fluorescence Spectrometry (XRF) and X-ray Diffractometor (XRD) studies revealed that the main phase of rice husk ash (after calcined at 600C for 6 h.) was amorphous silica, whereas the sugarcane bagasse ash contained quartz and CaCO3. Thus, both ashes would be a good source for silica. Two batches of the 100 wt% rice husk ash (RHA100) and the mixture of 50 wt% rice husk ash and 50 wt% bagasse ash (RHA50BA50) were wet milled using planetary ball milling machine, …
Green-Based Corrosion Protection For Mild Steel In 3.5% Nacl And Distilled Water Medias: Jatropha Curcas And Roselle Extracts,
2020
Chulalongkorn University
Green-Based Corrosion Protection For Mild Steel In 3.5% Nacl And Distilled Water Medias: Jatropha Curcas And Roselle Extracts, Muhammad A. Afandi, Safaa N. Saud, Esah Hamzah
Journal of Metals, Materials and Minerals
In this study, the natural sources of Jatropha curcas and Hibiscus Sabdariffa calynx (Roselle) extracts as green corrosion inhibitors were employed to improve the corrosion resistance of mild steel in simulated (3.5% NaCl) and distilled water medias. The inhibiting performance of two types of extracts was studied by visual inspection, microscope analysis, and various electrochemical measurements and the data of corrosion rate were statistically analyzed. The main phenolic compounds of Jatropha and Roselle extracts were confirmed via a liquid chromatography-mass spectrometry. Meanwhile, the functional groups of active phytochemical compounds were characterized via attenuated total reflection spectroscopy (ATR). The results of …
Properties Of Wood-Plastic Composites Based On Pvc/Pla/Pbat Ternary Blend,
2020
Chulalongkorn University
Properties Of Wood-Plastic Composites Based On Pvc/Pla/Pbat Ternary Blend, Laksamon Raksaksri, Phasawat Chaiwutthinan, Amnouy Larpkasemsuk, Saowaroj Chuayjuljit, Anyaporn Boonmahitthisud
Journal of Metals, Materials and Minerals
The objective of this work was to improve mechanical properties, thermal resistance, and biodegradability of poly(vinyl chloride) (PVC) by the addition of poly(lactic acid) (PLA), poly(butylene adipate-co-terephthalate) (PBAT), and wood flour (WF). The samples made from a mixture of PVC/PBAT exhibited the highest impact and tensile properties, while properties of the samples made from PVC/PLA had the highest flexural and thermal properties, PVC/PLA/PBAT mixed samples exhibited average mechanical properties. The addition of WF to all the blends increased impact strength, flexural properties, Young's modulus, thermal resistance, and biodegradability of the samples in comparison to those of the neat PVC and …
Synthesis Of Hydroxyapatite From Cuttlebone Under Various Ph Conditions: An Approach For Medical Materials,
2020
Chulalongkorn University
Synthesis Of Hydroxyapatite From Cuttlebone Under Various Ph Conditions: An Approach For Medical Materials, Sineenart Kangkan, Premjit Arpornmaeklong, Sarute Ummartyotin
Journal of Metals, Materials and Minerals
To support the bio-based economy, development on hydroxyapatite from cuttlebone was investigated. Cuttlebone is naturally occurring source of calcium. We calcined it at 700°C for 4 h to form a calcium oxide powder. Hydroxyapatite was coprecipitated with calcium oxide powder and phosphoric acid. The effect of the pH ranging from 6 - 10 was controlled by adding ammonium hydroxide. Fourier transform infrared and X-ray diffraction were employed to characterize the structural properties of the hydroxyapatite. Changes in pH did not affect the structural properties of the hydroxyapatite. Thermogravimetric analysis revealed that the hydroxyapatite was thermally stable up to 700°C. At …
Distributed Manufacturing Of Open Source Medical Hardware For Pandemics,
2020
Michigan Technological University
Distributed Manufacturing Of Open Source Medical Hardware For Pandemics, Joshua M. Pearce
Michigan Tech Publications, Part 1
Distributed digital manufacturing offers a solution to medical supply and technology shortages during pandemics. To prepare for the next pandemic, this study reviews the state-of-the-art of open hardware designs needed in a COVID-19-like pandemic. It evaluates the readiness of the top twenty technologies requested by the Government of India. The results show that the majority of the actual medical products have some open source development, however, only 15% of the supporting technologies required to produce them are freely available. The results show there is still considerable research needed to provide open source paths for the development of all the medical …
Tension-Tension Fatigue Behavior Of Nextel™ 720/Alumina-Mullite Ceramic Composite At 1200°C In Air And In Steam,
2020
Air Force Institute of Technology
Tension-Tension Fatigue Behavior Of Nextel™ 720/Alumina-Mullite Ceramic Composite At 1200°C In Air And In Steam, Sarah A. Witzgall
Theses and Dissertations
Uniaxial tension-tension fatigue performance of an oxide-oxide continuous fiber ceramic composite was studied at 1200°C in laboratory air and in steam. The composite is reinforced with laminated, 0/90 mullite/alumina (NEXTEL™720) fibers woven in an eight-harness satin weave and has a porous alumina/mullite matrix. There is no interphase between the fiber and matrix. The composite relies on the porous matrix for crack deflection and flaw tolerance. Tension-tension fatigue was examined for maximum stresses of 45 – 136 MPa in air and in steam. To assess the effects of the steam environment on fatigue performance, experimental results obtained in air are compared …
Design For Additive Manufacturing,
2020
California Polytechnic State University, San Luis Obispo
Design For Additive Manufacturing, Michael Charonnat, Leonardo Franco-Muñoz, Sam Noble, J.P. Purdom
Mechanical Engineering
This document outlines the critical design details and timeline for the Design for Additive Manufacturing Senior Project sponsored by Solar Turbines, Inc. The scope of this project encompasses the redesign of two of Solar Turbine’s cast parts for metal additive manufacturing in order to minimize lead time, cost, and weight. With the overall objective of performing in-depth analysis exploring affordability & feasibility, this redesign process will aid Solar Turbines in expanding their knowledge of Design for Additive Manufacturing principles and enable them to further incorporate the use of additive manufacturing into their production processes. The first part that the team …
Xas Analysis Of Copper Binding In Soils,
2020
Chulalongkorn University
Xas Analysis Of Copper Binding In Soils, Wapakorn Siriwong, Penphitcha Amonpattaratkit, Wantana Klysubun
Journal of Metals, Materials and Minerals
Ecological distribution of copper from soil is depended on its bioavailability and mobility. Copper binding on heterogeneous soil composition is a key information for understanding the long-term fate benefiting suitable management practice for copper in the environment. X-ray absorption spectroscopy (XAS) techniques were used to provide microscopic scale information of copper-binding on different soils. Soil samples containing 14.9-56.6% clay and 0.5-3.4% organic matter were studied. Dry-powder soil samples containing approximated 0.3% copper from batch equilibrated equilibrium experiments were analyzed. Copper K-edge spectrum were collected at the Synchrotron light research institute (SLRI), Thailand in X-ray absorption near edge structure (XANES) and …
Preparation Of Alginate/2-Hydroxyethyl Methacrylate Composite Beads: Role Of Fillers And Characteristics Of Bead Formation,
2020
Chulalongkorn University
Preparation Of Alginate/2-Hydroxyethyl Methacrylate Composite Beads: Role Of Fillers And Characteristics Of Bead Formation, Somkiet Urusetthanon, Somchai Udon, Boonsri Kusuktham
Journal of Metals, Materials and Minerals
In this research, alginate composite beads were prepared. The objective was to study the effect of particle size of fillers on the viscosity of alginate solution and bead formation. The sodium alginate solution with and without 2-hydroxyethyl methacrylate was dropped into calcium chloride to form the beads. The polymerization of the 2-hydroxyethyl methacrylate in the alginate matrix was occurred by using potassium persulphate as an initiator and N,N/-methylenebisacrylamide as a crosslinking agent and N,N,N/,N/ -tetramethylethylenediamine in the calcium chloride solution as an accelerator. For the preparation of the composite beads, the cotton dust, and sawdust at various ratios were mixed …
Effect Of Polystyrene Molecular Weight And Zinc Oxide Concentration On Dewetting Behavior Of Polymeric Thin Films,
2020
Chulalongkorn University
Effect Of Polystyrene Molecular Weight And Zinc Oxide Concentration On Dewetting Behavior Of Polymeric Thin Films, Kattaleeya Sujaroon, Phanawan Whangdee, Nampueng Pangpaiboon
Journal of Metals, Materials and Minerals
The separation between ultra-thin polymer film on metal oxide substrate is called dewetting. Dewetting causes the polymer films to loss their stability and other important properties, for example, the films may short circuit or reduce their transparency. Therefore, the stability of polymer thin films on substrate need to be improved. Addition of nanoparticles is one of the most popular technique used to increase the stability of polymer thin films. The correlation between the different of molecular weight and ZnO concentration on dewetting behavior was studied in this research. The appropriate concentration of ZnO on dewetting suppression in each molecular weight …
Effects Of Sodium Silicate As Liquid Phase Sintering Additives On Properties Of Alumina Ceramics,
2020
Chulalongkorn University
Effects Of Sodium Silicate As Liquid Phase Sintering Additives On Properties Of Alumina Ceramics, Kanyapak Siriphaisarntavee, Charusporn Mongkolkachit, Mateekul Jiarawattananon, Karn Serivalsatit, Thanakorn Wasanapiarnpong
Journal of Metals, Materials and Minerals
This research focused on the production of high-performance alumina products. The feasibility of using soluble alkali silicate in liquid phase sintering of alumina was studied. Liquid soluble alkali silicate was used to enhance the plastic forming of alumina and formed liquid phase sintering to attain fired alumina products with high strength, high alumina content and low water absorption. The methodology consisted of the mixing of organic binder with sodium silicate (Na2SiO3), used as liquid phase sintering additive, of 0-15 wt%. Magnesium carbonate (MgCO3), used as the grain growth inhibitor, of 0-1 wt% were added and followed by alumina powders. The …
Analysis Of Burning Wood In The Transient State And The Application To Structural Design,
2020
California Polytechnic State University, San Luis Obispo
Analysis Of Burning Wood In The Transient State And The Application To Structural Design, Roberta Veliz, Kimberly Guzman
Architectural Engineering
Determining the extent of the contribution of exposed timber on compartment fire dynamics in open floor plans is a complex process. Designers traditionally used compartmentalization design methods which create spaces where flashover is likely, given the fuel load and ventilation conditions. However, due to the large geometric dimensions and spread of fuel, fires in open floor plans are more likely to remain as localized or traveling fires. As such, an understanding of not only ignition potential but also flame spread is critical to characterizing the contribution of exposed timber. An integral step in characterizing the potential contribution is through an …
Effects Of Ring Rolling On Grain Size In Inconel 718 And Waspaloy,
2020
California Polytechnic State University, San Luis Obispo
Effects Of Ring Rolling On Grain Size In Inconel 718 And Waspaloy, David Webster
Materials Engineering
Carlton Forge Works, an industry leader in the manufacture of rolled rings, has observed anomalous grain structures in parts made from Inconel 718 and Waspaloy. These take the form of unusually large grains at the surface of the rings, causing them to fail industry grain size standards. Grain size testing is a critical part of evaluating parts before they are used as grain size and structure control many mechanical properties including creep resistance, low and high cycle fatigue life, and yield strength. These unusually large grains are only present within the first tenth of an inch of the surface of …
Microstructure And Tensile Properties Of Close-Die Forged Ti-6al-4v Aircraft Engine Mount,
2020
California Polytechnic State University, San Luis Obispo
Microstructure And Tensile Properties Of Close-Die Forged Ti-6al-4v Aircraft Engine Mount, Renee Roeder, Nick Chen, Michael Viksne
Materials Engineering
The microstructural characteristics of a Ti-6Al-4V close-die forging that passes yield strength specifications are examined and found to be consistent with literature recommendations. Originally, the intent was to compare the microstructure of a forging that passed specification to the microstructure of a forging that did not pass specifications using the imaging software ImageJ. Due to time and safety constraints considering the COVID-19 pandemic, the data that is presented is incomplete data on only the forging that passes specifications. There are no comparisons between the forging that did not pass and the forging that passed.
