Metallurgy Science Research Articles

Analytical and Numerical Solutions for Heat, Mass and Entropy Generation of Fourth Grade Nanofluid Flow Over A Vertical Plate

The focus of this research is to investigate magnetohydrodynamic flow, entropy generation, heat and mass transfer analysis for fourth grade nanofluid over a vertical plate in a porous medium subject to slip and convective boundary conditions. Lie group invariant similarity variable is used to transform the partial differential equations (PDEs) governing the problem to system of coupled nonlinear ordinary differential equations (ODEs). The resulting dimensionless ODEs are solved using Homotopy Perturbation Method (HPM). HPM results are validated with the numerical solutions via shooting method alongside the six order Runge-Kutta integration technique. The results revealed effects of new embedded governing flow parameters on velocity, temperature, entropy generation and concentration profiles.Furthermore, the impact of new embedded flow parameters on skin friction coefficient, Nusselt number and Sherwood number at the plate surface are investigated and the results are shown in tabular forms. The results indicate that suction on the plate can be used to control momentum, thermal and solutal boundary layer thickness. This research discovered that magnetic parameter, Eckert number, Biotsolutal number and Hartmann number can be respectively used to adjust fluid flow’s velocity, temperature, concentration and entropy generation. This research also detected that the force driving the fourth grade nanofluid flow called buoyancy driven force can be accelerated or decelerated by adjusting angle of magnetic field inclination. The present investigation has applications in industries and engineering, such as petroleum industries, chemical industries and metallurgy sciences

Research and complete the processing technology of Son La oxide copper ores for the Tay Bac Minerals Joint Stock Company

The copper ore processing plant of the Tay Bac Minerals Joint Stock Company has been designed and operated to produce metallic copper from copper sulphide ores and copper oxide ores in Son La province. Copper sulphide ores are processed to produce copper concentrates with content of more than 20% Cu for the next processing stage, while copper oxide ores, with average content of 1÷3% Cu and after grinding, are fed directly into hydrometallurgical processes to extract copper. However, this process requires large amount of chemicals. Therefore, the economic efficiency is not high. The National Institute of Mining - Metallurgy Science and Technology has researched and proposed a reasonable technology process for Son La copper oxide ores for solving difficulties and perfecting the processing technology at the plant that improves economic efficiency and minimizes environmental pollutions. This report presents results of the experimental production research project with the code CNKK.013.19, implemented by the Institute of Materials Science and sponsored by the Ministry of Industry and Trade.

Knowledge, attitude and practice of dental students, interns and practitioners to the use of amalgam in a dental institution of Kathmandu, Nepal

Background: Dental practitioners of Nepal have been using amalgam for years for restoration, but the concern for mercury related health issues and inventions in metallurgy science have recently led to its decreased use. 
 Objectives: To assess the knowledge, attitude and practice of students, interns and dentists to the use of dental amalgam in a dental institution of Kathmandu, Nepal.
 Methodology: A cross-sectional study was conducted in a dental institution of Kathmandu among 192 Dental students, interns, dental officers and dental specialists selected by census sampling method. Self-administered questionnaire consisting of 16 questions related to amalgam war, its use and safety was used. Data collected were analyzed using Statistical Package for Social Sciences version 20. Frequency and percentage were calculated for each response according to different professional levels. 
 Results: Most of the respondents including all the dental officers did not use amalgam frequently for restoration (141, 73.44%). Mercury toxicity was their major concern that restricted amalgam use (60, 31.25%). Most of them, (135, 70.31%) agreed on stopping the use of amalgam. They were comfortable to use composite resin as an alternative to amalgam (185, 96.35%). Majority (123, 64.06%) considered amalgam to be an unsafe material and were bothered about the environmental issues of mercury in the dental office (152, 79.16%).
 Conclusion: This study concludes that amalgam was less frequently used for restoration due to the increasing concerns of mercury toxicity. Further studies on safety of other materials that can replace amalgam with long term follow up are necessary before they are considered as a definitive alternative for amalgam.

Analysis of Entropy Generation Due to MHD Natural Convective Flow in an Inclined Channel in the Presence of Magnetic Field and Heat Source Effects

The main objective of the present paper is to investigate the entropy generation in a natural convective flow of a viscous incompressible electrically conducting fluid between two infinite non-conducting inclined parallel plates channel filled with a porous medium in the presence of transverse magnetic field and heat source. The governing non-linear partial differential equations are derived and solved analytically for velocity and temperature distribution with the help of the perturbation technique and their interpretation with physical parameters are shown through graphs. Also, the skin friction coefficient and rate of heat transfer in terms of Nusselt number are discussed numerically, and their numerical values for pertained physical parameters are presented through tables. In addition, total entropy generation rate and Bejan number due to heat transfer, fluid friction, and magnetic field are also discussed and their significance with all the pertained physical parameters are conferred through graphs. The results obtained through the present study are found a good agreement with previous research. It is perceived that an increment in the strength of the magnetic field declines the velocity of the fluid and prop-ups the rate of entropy generation. The present investigation has versatile applications in industries, engineering, and medical field, such as petroleum industries, chemical industries, metallurgy sciences, and treatment of cardiovascular disease in the medical field.

Thermal Science of Weld Bead Defects: A Review

Mechanisms for the formation of bead defects, such as humping, gouging, rippling, and other unexpected surface patterns, encountered in welding or drilling are interpreted and reviewed from thermal-fluid science viewpoint. These defects usually accompanying with porosity, undercut, segregation, stress concentration, etc., seriously reduce the properties and strength of the joint or solidification. Even though different mechanisms for formation of the defects have been extensively proposed in the past, more systematical understanding of pattern formations from thermal, fluid, physics, electromagnetic, pattern selections, and metallurgy sciences is still limited. The effects of working parameters and properties on humping and rippling, for example, can be systematically and quantitatively interpreted from scale analysis presented in this work. Good comparison with experimental results reveals mechanisms of different surface patterns. The mechanistic findings for bead defects are also useful for other manufacturing and materials processing.

A Nation of Steel: The Making of Modern America, 1865-1925.

From the age of railroads through the building of the first battleships, from the first skyscrapers to the dawning of the age of the automobile, steelmakers proved central to American industry, building, and transportation. In 'A Nation of Steel' Thomas Misa explores the complex interactions between steelmaking and the rise of the industries that have characterized modern America. Misa begins by showing how the transcontinental railroads' unprecedented demand for massive quantities of steel rails in the 1870s and 1880s led to the production of high-volume but low-quality Bessemer steel, and how that development influenced the American steel industry to this day. He describes how urbanization, including new building codes, led to changes in steel production that made possible the first American skyscrapers. And he explains why steel armor plate for battleships came to cost fifteen times more per ton than steel for rails, and how that discrepancy made Carnegie and Bethlehem the industry's leading companies. Subsequent chapters describe the increasing role played by the new science of metallurgy; the link between the invention of high-speed tool steel and the efficiency craze; and how demands of the automobile makers for a novel, high-tech consumer product gave rise to production of large volumes of high-quality steel. 'A Nation ofSteel' offers a detailed and fascinating look at an industry that has had a profound impact on American life.

Revisioning Sixteenth Century Solutions to Twentieth Century Problems in Herbert Hoover's Translation of Agricola's De Re Metallica

This article analyzes Herbert C. Hoover's translation of the De Re Metallica (1956) in the context of the 1922 Mine Strikes. The De Re Metallica combines practical instruction in mining techniques with a philosophical justification of the practice of mining. In Book I of the De Re Metallica, Agricola consciously constructs a rationalized science of metallurgy and mineralogy to enable expert miners to profit in a risky enterprise. Analysis of the text thus reveals that Hoover's interest in Agricola's “intellectual achievements” may have been more than technical. The economical and political assumptions that drive Agricola's arguments—justification of mining as a profit-making enterprise, his notions that accidents occur because workers are careless, and his rhetorical use of the notion of scientific expertise—framed many of the early twentieth century debates between mine operators and union organizers. In revisioning Agricola's arguments in the context of Hoover's own Principles of Mining and his statements in the 1922 Mine Crisis, this article demonstrates how technical documents reflect the political ideologies of their writers and how political arguments presented as purely technical debates shape the uses and construction of future technologies.

Modern Powder 15 Metallurgy Science and Technology

Powder metallurgy (P/M) has emerged as a source of new and viable manufacturing processes—with compelling economic and technical advantages over conventional ingot metallurgy practice. As well as delineating historical milestones and profiling today’s industry, this article reviews the modern approaches to powder production and consolidation from both the scientific and technological viewpoints. Some relationships between powder processing, microstructure and mechanical properties are discussed, with particular emphasis on the specialty alloys. Finally, an objective look at the interface between powder metallurgy and rapid solidification is presented.

Solid State Physics and Metallurgy

The art of metallurgy has been practised by man for several millennia, but the science of metallurgy has barely celebrated its first centenary. The science grew from the mineralogy and chemistry of the time, but the involvement of physics was slow.

Evidence of residual stress in small sections of ordinary green Eucalyptus regnans

Conclusive evidence is offered to show the existence of significant residual elastic stress in the form of alternate layers of tension and compression in relatively small pieces of normal green eucalyptus wood. A method of detecting residual stress in small samples of wood is described, and the stress distribution approximated from deflection measurements following a formula widely used in the science of metallurgy.

National Certificates in Metallurgy

THE Iron and Steel Institute, the Institution of Mining and Metallurgy and the Institute of Metals have joined forces to establish, in co-operation with the Ministry of Education, a scheme for Ordinary and Higher National Certificates in Metallurgy for part-time students who are engaged in industry or other pursuits connected with the science of metallurgy. The certificates will be awarded to students taking approved grouped courses of instruction at certain technical colleges and schools in England and Wales and reaching a certain standard in the final examinations. Examinations will be conducted by the college or school authorities, but syllabuses and examinations based on those of the City and Guilds of London Institute, Department of Technology, or the regional examining unions may, at their discretion, be submitted. The Ordinary National Certificate will be awarded on the results of senior part-time courses, which will usually occupy three years. They will be adapted to the needs of students who have had full-time continuous education up to the age of 15 or 16 or have completed satisfactorily an appropriate part-time course. Senior courses will include adequate provision for chemistry, physics and mathematics; metallurgy will be introduced at appropriate stages and engineering drawing may also be included. The Higher National Certificate will be awarded on the result of advanced part-time courses. These will be suitable for students who have already gained the Ordinary National Certificate or who have reached a corresponding standard and will normally cover at least two years of part-time study. The courses will provide for more intensive study of various branches of metallurgy and will aim at reaching, within the limits of the subjects covered, the standard of university work.

Henry Cort Harold Carpenter, 1875-1940

The unexpected death on 13 September 1940 of Sir (Henry Cort) Harold Carpenter, as a result of an accident in South Wales, came as a great shock to his many personal friends, and to the large number of his admirers amongst the technical and scientific men in all parts of the world. This is a serious loss to the country he loved so much, to the science of metallurgy, for the advancement of which he made so many valuable contributions, and to all who had the privilege of having worked, or having been closely associated, with him. By his death an important link in the chain of metallurgical teaching and research is broken, for he came into the subject at that rather vital stage when physical chemistry and physics were being more intensively applied to the study of metals and their alloys. From 1902 up to the time of his death, he played a prominent part as a teacher, as an original investigator and as an organizer, in extending the boundaries of his subject and strengthening the scientific foundations on which it rests. In an unusual degree Carpenter possessed those qualities which generated in others a profound respect, admiration, and personal regard for him. These feelings developed spontaneously and were not due to any obvious desire on his part to cultivate them; they grew as a result of his natural modesty, transparent honesty, and keen sense of justice, all of which were outstanding features of his character.

The Use and Abuse of Metals

ON several occasions we have referred to the advances made in the science of metallurgy in recent years. The developments that have taken place in metals for all purposes during the last fifteen years or so have been most remarkable. The ferrous metals, in spite of great improvements in that particular field, no longer hold unchallenged the position they did a comparatively few years ago.