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Full-Text Articles in Engineering Science and Materials
Under Sleeper Pads: Field Investigation Of Their Role In Detrimental Impact Mitigation, Sakdirat Kaewunruen, Alex M. Remennikov
Under Sleeper Pads: Field Investigation Of Their Role In Detrimental Impact Mitigation, Sakdirat Kaewunruen, Alex M. Remennikov
Sakdirat Kaewunruen
Under sleeper pads (USPs) are the component installed under the concrete sleepers generally to improve railway track resilience. Initial development in Europe, particularly in Austria, has encouraged the adoption of the component around the world. In practice, the component has commonly been used in certain applications, mainly to moderate track stiffness in special locations such as turnouts, crossings, and level crossing. In heavy haul operation, the heavier wagons result in sturdier bogie structures, higher unsprung mass, and then higher level of wheel-rail interaction forces. Accordingly, the application of USPs to mitigate detrimental impact load consequence on track structure is presented …
Surface Hardness Of Friction Stir Welded Aa6063 Pipe, Azman Ismail, Mokhtar Awang
Surface Hardness Of Friction Stir Welded Aa6063 Pipe, Azman Ismail, Mokhtar Awang
AZMAN ISMAIL
The external surface hardness of friction stir welded aluminum alloy 6063 pipe joint was investigated in this paper. The 89mm of outside diameter pipe with 5mm of wall thickness was used as test pipe piece for this experiment on closed butt joint configuration by utilising Bridgeport 2216 CNC milling machine and orbital clamping unit specially designed to cater for this task and function. Several welded samples were produced on varying process parameters which were successfully joined by using a non-consumable tool with a flat shoulder and a cylindrical pin.
Surface Hardness Of Friction Stir Welded Aa6063 Pipe, Azman Ismail, Mokhtar Awang
Surface Hardness Of Friction Stir Welded Aa6063 Pipe, Azman Ismail, Mokhtar Awang
Azman Ismail
The external surface hardness of friction stir welded aluminum alloy 6063 pipe joint was investigated in this paper. The 89mm of outside diameter pipe with 5mm of wall thickness was used as test pipe piece for this experiment on closed butt joint configuration by utilising Bridgeport 2216 CNC milling machine and orbital clamping unit specially designed to cater for this task and function. Several welded samples were produced on varying process parameters which were successfully joined by using a non-consumable tool with a flat shoulder and a cylindrical pin.
Think Outside The Box: New Materials, Design Application, And Performance Of Railway Turnout Bearers, Sakdirat Kaewunruen
Think Outside The Box: New Materials, Design Application, And Performance Of Railway Turnout Bearers, Sakdirat Kaewunruen
Sakdirat Kaewunruen
Railway turnout systems are a main feature in railway tracks. There are two types of turnout support structures, which can be designed to be either a slab or a cluster of discrete bearers. The choice of turnout support system depends on asset management strategy of the rail operators or maintainers. This paper will focus on the discrete turnout bearer system where turnout alignments, settlement and deformation are comparatively more flexible and retrievable by routine ballast tamping. It embraces the consideration of new materials for use as a turnout bearer. Traditional bearer materials are timber, steel, and concrete. Recent developments have …
Friction Stir Welding On Aluminum Alloy 6063 Pipe, Azman Ismail, Mokhtar Awang, Hasan Fawad, Kamal Ahmad
Friction Stir Welding On Aluminum Alloy 6063 Pipe, Azman Ismail, Mokhtar Awang, Hasan Fawad, Kamal Ahmad
Azman Ismail
For Friction Stir Welding (FSW) process, a substantial amount of research done on aluminium plate but very few are found for aluminium pipe due to its tubular shape. A specially customised Orbital Clamping Unit (OCU) was used and fixed on the Bridgeport 2216 CNC milling machine in order to run the FSW on aluminium alloy 6063 pipe butt joint at several welding parameters. This OCU will hold these pipes together tightly, rotate these pipes at the required constant low speed, and ensure easy removal of pipe after the welding process before proceeding for further testing. This paper will study the …
Travelling In Cuba, Fathi Habashi
Travelling In Cuba, Fathi Habashi
Fathi Habashi
Contact with Cuban scientists was established in 1986 when two researchers from Centro de Investigaciones para Industria Minero Metalurgica in Havana visited Laval University to get acquainted with research activities in the area of extractive metallurgy. This was followed in early 1987 by two more researchers from the same centre. Invitations were then received in late 1987, 1989, and 2008 to visit the nickel refineries in Cuba and to hold seminars at the University of Havana. The present report outlines these activities.
Experimental Verification Of The Linear Relationship Between Stress And The Reciprocal Of The Peak Barkhausen Voltage In Astm A36 Steel, Orfeas Kypris, Ikenna Nlebedim, David Jiles
Experimental Verification Of The Linear Relationship Between Stress And The Reciprocal Of The Peak Barkhausen Voltage In Astm A36 Steel, Orfeas Kypris, Ikenna Nlebedim, David Jiles
Orfeas Kypris
This study presents an experimental validation of a model theory for determining the relationship between a nondestructive measurement parameter and a property of interest. It was found that the reciprocal of the peak envelope amplitude of the Barkhausen emission voltage follows a linear relationship with stress. A linear relationship between stress and the reciprocal of the root mean square voltage was also obtained. These observations represent an important step towards improving the use of Barkhausen signals for magnetic non-destructive evaluation of stress as a function of depth in ferromagnetic load bearing structures.
Conceptual Design For Treatment Of Mining And Metallurgical Wastewaters Which Contains Arsenic And Antimony, Zeljko J. Kamberovic
Conceptual Design For Treatment Of Mining And Metallurgical Wastewaters Which Contains Arsenic And Antimony, Zeljko J. Kamberovic
Zeljko J Kamberovic
This paper presents a preliminary design for treatment of mining and metallurgical wastewaters (MMW) from the basin of antimony “Zajača“, which contains high concentrations of arsenic and antimony. MMW have been investigated in laboratory, due to large difference in concentrations of pollutants. Metallurgical wastewaters were treated using iron (II)-sulfate and lime milk used to adjust the pH value at 7. After chemical treatment of metallurgical wastewater and its joining with mining wastewater, residual amount of arsenic in water was below maximum allowed concentrations, while the concentration of antimony, remained above the maximum allowed value. The final phase of purification process …
Pyrite. History, Chemistry, And Metallurgy, Fathi Habashi
Pyrite. History, Chemistry, And Metallurgy, Fathi Habashi
Fathi Habashi
The Book covers the history of pyrite - - how it was a strategic mineral necessary for the production of elemental sulfur needed for making gunpowder for military purposes and for the production of SO2 needed for making sulfuric acid for the chemical industry. Now its presence is a nuisance in tailings ponds. The book also covers the processing of pyrite containing gold, its chemistry and technology, the processing of pyrite cinder for the production of a variety of metals, and its behaviour towards autotrophic microorganisms.
Hydrometallurgical Process For Extraction Of Metals From Electronic Waste-Part Ii: Development Of The Processes For The Recovery Of Copper From Printed Circuit Boards (Pcb), Zeljko J. Kamberovic
Hydrometallurgical Process For Extraction Of Metals From Electronic Waste-Part Ii: Development Of The Processes For The Recovery Of Copper From Printed Circuit Boards (Pcb), Zeljko J. Kamberovic
Zeljko J Kamberovic
Rapid technological development induces increase of generation of used electric and electronic equipment waste, causing a serious threat to the environment. Waste printed circuit boards (WPCBs), as the main component of the waste, are significant source of base and precious metals, especially copper and gold. In recent years, most of the activities on the recovery of base and precious metals from waste PCBs are focused on hydrometallurgical techniques as more exact, predictable and easily controlled compared to conventional pyrometallurgical processes. In this research essential aspects of the hydrometallurgical processing of waste of electronic and electrical equipment (WEEE) using sulfuric acid …
Transferts De Chaleur Dans Un Réacteur Thermochimique Solaire Muni D’Un Récepteur Volumique Poreux, Hernando Romero Paredes Rubio
Transferts De Chaleur Dans Un Réacteur Thermochimique Solaire Muni D’Un Récepteur Volumique Poreux, Hernando Romero Paredes Rubio
Hernando Romero Paredes Rubio
Un réacteur thermochimique solaire de 1 kW muni d’une structure céramique poreuse en céramique est modélisé pour simuler les transferts thermiques a l’intérieur du récepteur volumétrique. Le modèle développé a été utilisé pour prévoir le comportement thermique du réacteur en fonction des différentes conditions opératoires qui concernent le débit de gaz inerte, le flux solaire incident, la porosité, la longueur du récepteur, et la prise en compte de réactions chimiques. Les résultats montrent que la température maximale est de 1850K pour une concentration solaire de 1000 soleils. La température diminue de manière significative lorsque le débit de gaz augmente. Un …
Metalurgia Extractiva Y Política Nacional, Fathi Habashi
Metalurgia Extractiva Y Política Nacional, Fathi Habashi
Fathi Habashi
Should a country export its mineral wealth in form of concentrates or should it locally treat its ores to produce metals as final products? In the past centuries pyrometallurgy was the only route to extract metals from ores and this required a large capital investment many countries could not afford to raise. This situation encouraged marketing of concentrates. Today, metallurgists have the option to use the hydrometallurgical route to process ores and concentrates at a reasonable capital investment. This opened the way to the possibility of processing ores locally. When need arises to increase production new units can be added …
Leaching Mechanism Of Semiconducting Minerals, Fathi Habashi
Leaching Mechanism Of Semiconducting Minerals, Fathi Habashi
Fathi Habashi
The mechanism of leaching of semiconducting minerals such as PbS, ZnS, UO2, etc., has been the subject of intensive speculation by hydrometallurgists in the early 1950s. The electrochemical mechanism proposed in 1970 by the author in volume 2 of his Principles of Extractive Metallurgy avoids the assumption of forming intermediate complexes that cannot be isolated or identified.
Metals: Typical And Less Typical, Transition And Inner Transition, Fathi Habashi
Metals: Typical And Less Typical, Transition And Inner Transition, Fathi Habashi
Fathi Habashi
While most chemists agree on what is a metal and what is a non-metal there is a disagreement with respect to what is a metalloid and what is a transition metal. It is believed that this problem can be solved if two new terms are adopted: typical and less typical metals. These new terms will also help reconcile the European Periodic Table versus the North American regarding numbering of groups as well as the IUPAC numbering which could be as well abandoned in favour of group names as will be shown in the manuscript.
Phosphate Industry And The Radon Problem, Fathi Habashi
Phosphate Industry And The Radon Problem, Fathi Habashi
Fathi Habashi
The problem of radon generated during the treatment of phosphate rock by sulfuric acid to produce fertilizers can be solved by using nitric acid. In this case radium, which is the source of radon, goes into solution and can be precipitated by a controlled method and safely disposed of. A variety of options are discussed. Text in Farsi with English translation.
Possibility Of Secondary Lead Slag Stabilization In Concrete With Presence Of Selected Additives, Zeljko J. Kamberovic
Possibility Of Secondary Lead Slag Stabilization In Concrete With Presence Of Selected Additives, Zeljko J. Kamberovic
Zeljko J Kamberovic
A comparative technical and environmental evaluation of products arising from the stabilization/solidification of secondary lead metallurgical slag into a cement matrix was performed. Provided samples of an industrial slag generated in the process of recovery of lead from automotive batteries (Engitec CX process), were used in experimental work. Characterization of slag by X-ray Diffraction (XRD), Atomic Absorption Spectrometry (AAS) and Optical Microscopy (OM) revealed that slag contains a certain percentage of sodium and lead, in the form of oxides and sulphides, as well as unreacted coke and iron compounds. Dissolving of the slag components causes migration of ions into water …
My Curriculum Vitae (As January 2013), Yun Hau Ng
My Curriculum Vitae (As January 2013), Yun Hau Ng
Yun Hau Ng
References available upon request
Aqua Science Through The Ages. An Illustrated History Of Water, Fathi Habashi
Aqua Science Through The Ages. An Illustrated History Of Water, Fathi Habashi
Fathi Habashi
Water a component of the Four Elements considered by the ancient philosophers as essential for survival, played, and is still playing an essential role in society. Great civilizations in ancient times developed along great rivers. The ancient peoples knew how to manage water supplies by digging canals, controlling floods, and using water for irrigation. They designed equipment that used water to measure the time, to determine the density of solids, to fight fires, and to create vacuum. Modern engineers exploited water flow to design and construct huge hydroelectric power stations. Waterways and navigation systems were also an essential element for …
Hydrometallurgical Process For Extraction Of Metals From Electronic Waste-Part I: Material Characterization And Process Option Selection, Zeljko J. Kamberovic
Hydrometallurgical Process For Extraction Of Metals From Electronic Waste-Part I: Material Characterization And Process Option Selection, Zeljko J. Kamberovic
Zeljko J Kamberovic
Used electronic equipment became one of the fastest growing waste streams in the world. In the past two decades recycling of printed circuit boards (PCBs) has been based on pyrometallurgy, higly polluting recycling technology whic causes a variety of environmental problems. The most of the contemporary research activities on recovery of base and precious metals from waste PCBs are focused on hydrometallurgical techniques as more exact, predictable and easily controlled. In this paper mechanically pretrated PCBs are leached with nitric acid. Pouring density, percentage of magnetic fraction, particle size distribution, metal content and leachability are determined using optical microscopy, atomic …
Effect Of Non-Stationary Current Regimes On The Morphology Of Silver Electrodeposits, Zeljko J. Kamberovic
Effect Of Non-Stationary Current Regimes On The Morphology Of Silver Electrodeposits, Zeljko J. Kamberovic
Zeljko J Kamberovic
This work is concerned with the use of reverse current regimes in order to form small-grained and compact silver deposits during the electrorefining process. Several parameters were varied, i.e., i) anodic overpotential, ii) cathodic vs. anodic time ratio and iii) duration of the anodic pulse. After optimization of these parameters, phosphate ions were added and the electrolyte was stirred. The effects of a rise of the anodic overpotential on the grain sizes of the silver deposit and compactness were studied. Prolongation of the anodic time had a similar influence but with a decrease in current efficiency. An increase of the …
Chemistry And Metallurgy In The Great Empires, Fathi Habashi
Chemistry And Metallurgy In The Great Empires, Fathi Habashi
Fathi Habashi
It is remarkable that certain countries expand to become great empires then as time goes by they gradually decline while others rise. This book attempts to briefly trace the history of chemistry and metallurgy through the different empires that became at one time great and then faded away. In 272 pages 21.5 x 28 cm, the author outlines the inter-relation of chemistry, metallurgy, mining, and medicine, the idea of the divinity of kings and the formation of nations, and finally the rise and fall of the empires. He then covers the ancient and medieval empires, followed by the empires from …
Science, Technology, And Society, Fathi Habashi
Science, Technology, And Society, Fathi Habashi
Fathi Habashi
Science, technology, and society is a vast and complex question. It is discussed here from five points: social responsibility of scientists, migration and movement of scholars, philanthropy and its role in education and culture, enlightened despots and their influence on science and culture, and finally the social aspects of mining. The book is meant for the general reader but can benefit scientists as well. It is fully illustrated with colored pictures. It is hoped that it will serve as an introduction to this field to the young generation and inspire them to serve society.
Effect Of Concentration On Electrospun Polyacrylonitrile (Pan) Nanofibers, Ji-Huan He, Yu-Qin Wan, Jian-Yong Yu
Effect Of Concentration On Electrospun Polyacrylonitrile (Pan) Nanofibers, Ji-Huan He, Yu-Qin Wan, Jian-Yong Yu
Ji-Huan He
Abstract: An allometrical scaling relationship between the diameter of electrospun nanofiber and solution concentration is established, the scaling exponent differs greatly between different polymers and the same polymer with different molecules or the same molecules with different properties. The diameter of electrospun polyacrylonitrile (PAN) nanofibers increases approximately linearly with solution concentration.
Nanocomposite Powders For New Contact Materials Based On Copper And Alumina, Zeljko J. Kamberovic
Nanocomposite Powders For New Contact Materials Based On Copper And Alumina, Zeljko J. Kamberovic
Zeljko J Kamberovic
This paper is a contribution to characterization of Cu-Al2O3 powders with nanostructure designed for the production of dispersion strengthened contact materials. New materials with predetermined properties can be successfully synthesized by utilizing the principles of hydrometallurgy and powder metallurgy. The results show a development of a new procedure for the synthesis. The applied characterization methods were differential thermal and thermogravimetric analysis (DTA-TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), Transmission Electron Microscopy (TEM): Focused Ion Beam (FIB) and Analytical Electron Microscopy (AEM). Nanostructure characteristics, particle size in range 20-50 nm, and uniform distribution of dispersoide in copper matrix were validated.
Determination Of Al2o3 Particle Size In Cu-Al2o3 Nanocomposite Materials Using Uv Spectrophotometry, Zeljko J. Kamberovic
Determination Of Al2o3 Particle Size In Cu-Al2o3 Nanocomposite Materials Using Uv Spectrophotometry, Zeljko J. Kamberovic
Zeljko J Kamberovic
In order to achieve improved mechanical properties of dispersion strengthened nanocomposite, without influencing electrical and thermal conductivity it is necessary for dispersoide to be nano sized and uniformly distributed in base metal matrix. In this paper are presented the results concerning possibility of using UV spectrophotometry for determination of alumina particle size in Cu-Al2O3 system. Presented results show that this method is unefficient as method for determination of dispersoide particle size, due to the coalescence of particles false results are obtained, i.e. particle size significantly higher then one determined by image analysis.
Structural Characteristics Of Some Ternary Ag-In-Sn Alloys, Zeljko J. Kamberovic
Structural Characteristics Of Some Ternary Ag-In-Sn Alloys, Zeljko J. Kamberovic
Zeljko J Kamberovic
The Ag-In-Sn system, as one of potential lead-free solder materials, was studied in this paper. The investigated alloys were chosen from two sections, with molar ratio of In:Sn equal to 1:4; 1:2. DTA, XRD, SEM and microhardness investigations were used in order to determine structural characteristics of chosen Ag-In-Sn ternary alloys.
Mode-I Toughness And Curing Pressure Characterisitc Of Symmetrical Lay-Up Of Plain Weave Woven Gfrp Composites, Mohd Aidy Faizal Johari, Kiam Beng Yeo, Mohd Noh Dalimin
Mode-I Toughness And Curing Pressure Characterisitc Of Symmetrical Lay-Up Of Plain Weave Woven Gfrp Composites, Mohd Aidy Faizal Johari, Kiam Beng Yeo, Mohd Noh Dalimin
mohd aidy faizal johari
This study describes an experimental study on the interlaminar Mode-I fracture toughness behavior of hand lay-up plain-weave woven GFRP laminate by using a fracture energy method of evaluation. Mode-I double cantilever beam (DCB) tests were performed on woven GFRP unsaturated polyester composite, E-Glass EWR 600 NISER, specimens. The specimen design and test procedure are performed with reference to the BS ISO 15024 and ASTM D5528. Various curing uniform pressure distribution has been investigated at 35.8kg/m2, 70.1kg/m2, 104kg/m2 and 138.2kg/m2, with respect to the toughness value. The lay-up laminates designed with symmetrical arrangement at the center-plane of the composite are also …
Forest Products Laboratory: Supporting The Nation's Armed Forces With Valuable Wood Research For 90 Years, Christopher D. Risbrudt, Robert J. Ross, Julie J. Blankenburg, Charles A. Nelson
Forest Products Laboratory: Supporting The Nation's Armed Forces With Valuable Wood Research For 90 Years, Christopher D. Risbrudt, Robert J. Ross, Julie J. Blankenburg, Charles A. Nelson
Julie Blankenburg
Founded in 1910 by the U.S. Forest Service to serve as a centralized, national wood research laboratory, the USDA Forest Products Laboratory (FPL) has a long history of providing technical services to other government agencies, including those within the Department of Defense (DoD). A recent search of FPL’s library and correspondence files revealed that approximately 10,000 articles, reports, manuals, other technical publications, and communications have been generated and provided to the DoD since 1910. FPL has provided support on a broad array of technical questions—from designporting materiel to Europe and the South Pacific during World War II to assisting in …
Selective Removal Of Heavy Metals From Metal-Bearing Wastewater In A Cascade Line Reactor, Zeljko J. Kamberovic
Selective Removal Of Heavy Metals From Metal-Bearing Wastewater In A Cascade Line Reactor, Zeljko J. Kamberovic
Zeljko J Kamberovic
This paper is a part of the research work on 'Integrated treatment of industrial wastes towards prevention of regional water resources contamination – INTREAT' the project. It addresses the environmental pollution problems associated with solid and liquid waste/effluents produced by sulfide ore mining and metallurgical activities in the Copper Mining and Smelting Complex Bor (RTB-BOR), Serbia. However, since the minimum solubility for the different metals usually found in the polluted water occurs at different pH values and the hydroxide precipitates are amphoteric in nature, selective removal of mixed metals could be achieved as the multiple stage precipitation. For this reason, …
Sintering Of Cu–Al2o3 Nano-Composite Powders Produced By A Thermochemical Route, Zeljko J. Kamberovic
Sintering Of Cu–Al2o3 Nano-Composite Powders Produced By A Thermochemical Route, Zeljko J. Kamberovic
Zeljko J Kamberovic
This paper presents the synthesis of nano-composite Cu–Al2O3 powder by a thermochemical method and sintering, with a comparative analysis of the mechanical and electrical properties of the obtained solid samples. Nano-crystalline Cu–Al2O3 powders were produced by a thermochemical method through the following stages: spray-drying, oxidation of the precursor powder, reduction by hydrogen and homogenization. Characterization of powders included analytical electron microscopy (AEM) coupled with energy dispersive spectroscopy (EDS), differenttial thermal and thermogravimetric (DTA–TGA) analysis and X-ray diffraction (XRD) analysis. The size of the produced powders was 20–50 nm, with a noticeable presence of agglomerates. The composite powders were characterized by …