WorldWideScience

Sample records for technology chemistry metallurgy

  1. Chemistry Technology

    Data.gov (United States)

    Federal Laboratory Consortium — Chemistry technology experts at NCATS engage in a variety of innovative translational research activities, including:Design of bioactive small molecules.Development...

  2. Electrodeposition in extractive metallurgy: An emerging technology?

    Science.gov (United States)

    O'Keefe, Thomas J.

    1992-04-01

    The electrowinning and electrorefining of metals from aqueous solutions continues to be one of the essential unit processes employed in nonferrous extractive metallurgy. Current processes effectively address both ohmic and mass transport of the primary metal ion in their design. Some deficiencies exist, however, in the basic understanding of the other two critical elements essential in cathodic deposition: activation kinetics and electrocrystallization. The understanding of the latter two must be elevated to the level of understanding of ohmic and mass transport if truly new and innovative advances are to occur. Because of the increasingly demanding standards for electrometallurgy processes and products, technical progress must be made if a competitive edge is to be maintained in the future.

  3. Solvent extraction:The coordination chemistry behind extractive metallurgy

    OpenAIRE

    2014-01-01

    The modes of action of the commercial solvent extractants used in extractive hydrometallurgy are classified according to whether the recovery process involves the transport of metal cations, Mn+, metalate anions, MXxn-, or metal salts, MXx into a water-immiscible solvent. Well-established principles of coordination chemistry provide an explanation for the remarkable strengths and selectivities shown by most of these extractants. Reagents which achieve high selectivity when transporting metal ...

  4. Solvent extraction: the coordination chemistry behind extractive metallurgy.

    Science.gov (United States)

    Wilson, A Matthew; Bailey, Phillip J; Tasker, Peter A; Turkington, Jennifer R; Grant, Richard A; Love, Jason B

    2014-01-07

    The modes of action of the commercial solvent extractants used in extractive hydrometallurgy are classified according to whether the recovery process involves the transport of metal cations, M(n+), metalate anions, MXx(n-), or metal salts, MXx into a water-immiscible solvent. Well-established principles of coordination chemistry provide an explanation for the remarkable strengths and selectivities shown by most of these extractants. Reagents which achieve high selectivity when transporting metal cations or metal salts into a water-immiscible solvent usually operate in the inner coordination sphere of the metal and provide donor atom types or dispositions which favour the formation of particularly stable neutral complexes that have high solubility in the hydrocarbons commonly used in recovery processes. In the extraction of metalates, the structures of the neutral assemblies formed in the water-immiscible phase are usually not well defined and the cationic reagents can be assumed to operate in the outer coordination spheres. The formation of secondary bonds in the outer sphere using, for example, electrostatic or H-bonding interactions are favoured by the low polarity of the water-immiscible solvents.

  5. Environmental aspects of innovation and new technology implementation in metallurgy industry

    Directory of Open Access Journals (Sweden)

    I. Kłosok-Bazan

    2015-04-01

    Full Text Available European metallurgy industry has to invest in innovations and new technologies in order to remain competitive on the world market. Because very often this action leads to limitation of the negative impact upon the environment,that is why lots of innovations implemented by iron and steel industry bear the features of environmental innovations and eco-innovations in metallurgy industry. The analysis of the environmental innovations and eco-innovations implementation in metallurgy industry, in terms of legal regulations in the environmental protection and the strategy area of sustainable development of enterprises, is the subject matter of this article.

  6. Advanced powder metallurgy aluminum alloys via rapid solidification technology

    Science.gov (United States)

    Ray, R.

    1984-01-01

    Aluminum alloys containing 10 to 11.5 wt. pct. of iron and 1.5 to 3 wt. pct. of chromium using the technique of rapid solidification powder metallurgy were studied. Alloys were prepared as thin ribbons (.002 inch thick) rapidly solidified at uniform rate of 10(6) C/second by the melt spinning process. The melt spun ribbons were pulverized into powders (-60 to 400 mesh) by a rotating hammer mill. The powders were consolidated by hot extrusion at a high reduction ratio of 50:1. The powder extrusion temperature was varied to determine the range of desirable processing conditions necessary to yield useful properties. Powders and consolidated alloys were characterized by SEM and optical metallography. The consolidated alloys were evaluated for (1) thermal stability, (2) tensile properties in the range, room temperature to 450 F, and (3) notch toughness in the range, room temperature to 450 F.

  7. Metallurgy Department

    DEFF Research Database (Denmark)

    Risø National Laboratory, Roskilde

    The activities of the Metallurgy Department at Risø during 1981 are described. The work is presented in three chapters: General Materials Research, Technology and Materials Development, Fuel Elements. Furthermore, a survey is given of the department's participation in international collaboration...

  8. Possibilities for saving energy in ferrous metallurgy: Integration of technological processes

    Directory of Open Access Journals (Sweden)

    Mihailov Emil

    2016-01-01

    Full Text Available One of the main factors having a significant effect on fuel and energy saving in the production of rolled ferrous metals is matching the operation of the continuous casting machines (CCM with that of the reheating furnaces so called “continuous technologies” in the form of “direct rolling” or “hot charging”. In order to investigate the heat exchange processes, the opportunities for enhancing the energy efficiency and determining the optimal parameters of the flat product production process in ferrous metallurgy, some mathematical models of metal solidification and cooling in a continuous steel casting machine were determined as well as a mathematical model of metal heating in the reheating furnaces. For efficient implementation of such technologies one common algorithm was built on the basis of the individual mathematical models, representing the continuous casting - rolling mill complex control technology, dynamically matching the operation of the individual units to the actual production conditions in on-line mode. The developed algorithm can be used as part of a system for analyzing the thermal condition of the blocks at any single moment for the purpose of optimization of the units’ operation within the whole technological process. As a conclusion, considering the original developed algorithm, a 21-51% energy saving was noticed.

  9. The Los Alamos National Laboratory Chemistry and Metallurgy Research Facility upgrades project - A model for waste minimization

    Energy Technology Data Exchange (ETDEWEB)

    Burns, M.L.; Durrer, R.E.; Kennicott, M.A.

    1996-07-01

    The Los Alamos National Laboratory (LANL) Chemistry and Metallurgy Research (CMR) Facility, constructed in 1952, is currently undergoing a major, multi-year construction project. Many of the operations required under this project (i.e., design, demolition, decontamination, construction, and waste management) mimic the processes required of a large scale decontamination and decommissioning (D&D) job and are identical to the requirements of any of several upgrades projects anticipated for LANL and other Department of Energy (DOE) sites. For these reasons the CMR Upgrades Project is seen as an ideal model facility - to test the application, and measure the success of - waste minimization techniques which could be brought to bear on any of the similar projects. The purpose of this paper will be to discuss the past, present, and anticipated waste minimization applications at the facility and will focus on the development and execution of the project`s {open_quotes}Waste Minimization/Pollution Prevention Strategic Plan.{close_quotes}

  10. Innovative technologies for powder metallurgy-based disk superalloys: Progress and proposal

    Science.gov (United States)

    Chong-Lin, Jia; Chang-Chun, Ge; Qing-Zhi, Yan

    2016-02-01

    Powder metallurgy (PM) superalloys are an important class of high temperature structural materials, key to the rotating components of aero engines. In the purview of the present challenges associated with PM superalloys, two novel approaches namely, powder preparation and the innovative spray-forming technique (for making turbine disk) are proposed and studied. Subsequently, advanced technologies like electrode-induction-melting gas atomization (EIGA), and spark-plasma discharge spheroidization (SPDS) are introduced, for ceramic-free superalloy powders. Presently, new processing routes are sought after for preparing finer and cleaner raw powders for disk superalloys. The progress of research in spray-formed PM superalloys is first summarized in detail. The spray-formed superalloy disks specifically exhibit excellent mechanical properties. This paper reviews the recent progress in innovative technologies for PM superalloys, with an emphasis on new ideas and approaches, central to the innovation driving techniques like powder processing and spray forming. Project supported by the National Natural Science Foundation of China (Grant Nos. 50974016 and 50071014).

  11. Effects of porosity on corrosion resistance of Mg alloy foam produced by powder metallurgy technology

    Energy Technology Data Exchange (ETDEWEB)

    Aghion, E., E-mail: egyon@bgu.ac.il; Perez, Y.

    2014-10-15

    Magnesium alloy foams have the potential to serve as structural material for regular light-weight applications as well as for biodegradable scaffold implants. However, their main disadvantage relates to the high reactivity of magnesium and consequently their natural tendency to corrode in regular service conditions and in physiological environments. The present study aims at evaluating the effect of porosity on the corrosion resistance of MRI 201S magnesium alloy foams in 0.9% NaCl solution and in phosphate buffer saline solution as a simulated physiological electrolyte. The magnesium foams were produced by powder metallurgy technology using space-holding particles to control the porosity content. Machined chips were used as raw material for the production of Mg alloy powder by milling process. The microstructure of the foams was examined using optical and scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy analysis. The corrosion behavior was evaluated by immersion test and potentiodynamic polarization analysis. The results obtained clearly demonstrate that the porosity has a significant effect on the corrosion resistance of the tested foams. Foams with 14–19% porosity have a corrosion rate of 4–10 mcd and 7–15 mcd in NaCl and phosphate buffer saline solution, respectively, compared to only 0.10 mcd for the same alloy in as cast conditions. This increased corrosion degradation of the Mg foams by more than one order of magnitude compared to the cast alloy may limit their potential application in regular and physiological environments. - Highlights: • Porosity has a detrimental effect on corrosion resistance of MRI 201S Mg foams. • 14–19% porosity increases the corrosion rate by more than one order of magnitude. • Accelerated corrosion limits the use of foams in regular/physiological environments.

  12. A Guide for Planning Facilities for Occupational Preparation Programs in Metallurgy Technology. Interim Report. Research 28.

    Science.gov (United States)

    German, Carl, Jr.

    The major purpose of this guide is to elicit the information necessary for writing educational specifications for facilities to house technical education programs in metallurgy. It is organized in these parts: (1) Part I discusses the major purpose, underlying assumptions, recent instructional trends, and guiding principles utilized in the…

  13. History of ``NANO''-Scale VERY EARLY Solid-State (and Liquid-State) Physics/Chemistry/Metallurgy/ Ceramics; Interstitial-Alloys Carbides/Nitrides/Borides/...Powders and Cermets, Rock Shocks, ...

    Science.gov (United States)

    Maiden, Colin; Siegel, Edward

    History of ``NANO'': Siegel-Matsubara-Vest-Gregson[Mtls. Sci. and Eng. 8, 6, 323(`71); Physica Status Solidi (a)11,45(`72)] VERY EARLY carbides/nitrides/borides powders/cermets solid-state physics/chemistry/metallurgy/ ceramics FIRST-EVER EXPERIMENTAL NANO-physics/chemistry[1968 ->Physica Status Solidi (a)11,45(`72); and EARLY NANO-``physics''/NANO-``chemistry'' THEORY(after: Kubo(`62)-Matsubara(`60s-`70s)-Fulde (`65) [ref.: Sugano[Microcluster-Physics, Springer('82 `98)

  14. Plutonium Metallurgy

    Energy Technology Data Exchange (ETDEWEB)

    Freibert, Franz J. [Los Alamos National Laboratory

    2012-08-09

    Due to its nuclear properties, Pu will remain a material of global interest well into the future. Processing, Structure, Properties and Performance remains a good framework for discussion of Pu materials science Self-irradiation and aging effects continue to be central in discussions of Pu metallurgy Pu in its elemental form is extremely unstable, but alloying helps to stabilize Pu; but, questions remain as to how and why this stabilization occurs. Which is true Pu-Ga binary phase diagram: US or Russian? Metallurgical issues such as solute coring, phase instability, crystallographic texture, etc. result in challenges to casting, processing, and properties modeling and experiments. For Ga alloyed FCC stabilized Pu, temperature and pressure remain as variables impacting phase stability.

  15. Peat, industrial chemistry and technology

    Energy Technology Data Exchange (ETDEWEB)

    Fuchsman, C.H.

    1980-01-01

    This book is an attempt to enable chemists, engineers, and managers in North America and Western Europe to assess the industrial potential of peat. The chemical characteristics of peat, peat bitumens and peat carbohydrates are described. The technical matter concerns (1) solvent extraction processes, leading to the production of waxes and of by-products of potential interest in pharmaceutical chemistry; (2) acid hydrolysis, leading to the production of sugars supporting yeast products for high-protein livestock feed, and alcohol production, (3) pyrolysis, leading to the production of speciality high-production metallurgical coke, and activated carbon; and (4) the alkaline extraction of humic acids, leading to a variety of surface active agents, viscosity modifiers, and possible ingredients for the plastics and adhesive industries. The more important environmental aspects for man and nature are pointed out. (463 refs.)

  16. Technological Aspects of High Speed Direct Laser Deposition Based on Heterophase Powder Metallurgy

    Science.gov (United States)

    Turichin, G. A.; Klimova, O. G.; Zemlyakov, E. V.; Babkin, K. D.; Kolodyazhnyy, D. Yu.; Shamray, F. A.; Travyanov, A. Ya.; Petrovskiy, P. V.

    The article deals with physical peculiarities and technology of high speed processes of direct laser deposition. On the base of theoretic research and computer modeling the powder transfer has been optimized, increasing process stability and productivity. Principles of nozzles design also have been developed in accordance with technological needs. An influence of process mode on product properties and material structure was defined for heat resisted Ni-based superalloys. Developed technology provided the mechanic properties of products on the level of rolled material and allows avoid heat treatment and HIP in production process. Possible ways for increasing process performance and economic efficiency also have been discussed.

  17. JPRS Report, Science & Technology USSR: Chemistry.

    Science.gov (United States)

    2007-11-02

    issued by the control computer system. This is accom- plished either on the basis of readings from the respec- tive sensors or else on the basis of...Shershukov, S.F. Kramarenko, LB. Nem - chenok, L.N. Veselova, and A.P. Tomilov, State Union Scientific Research Institute of Organic Chemistry and Technology...considered. Because there is no lengthy (15 to 18 hours) and corrosive decarbonization stage, the power consumption and labor input required for the

  18. Preparation of Aluminum Foam Sandwich by Rolling-bonding/Powder Metallurgy Foaming Technology

    Institute of Scientific and Technical Information of China (English)

    ZU Guoyin; SONG Binna; GUAN Zhihao; WANG Lei; YAO Guangchun

    2011-01-01

    Aluminum foam sandwich was prepared by rolling-bonding/powder metallurgical foaming technology,and the effects of rolling on bond strength of face sheet/powders and powder density were studied.Moreover,the foaming agent,TiH2,was heat treated and a certain amount of Mg was added into powder in an attempt to understand how the stability and uniformity of foam was improved.The experimental results show that the foaming precursors with ideal quality were obtained by rolling-bonding process.When rolling reduction is 67%,the consistency of powders reach to 99.87%.Throughout consideration of the bonding of face sheet/core layer powders and deformation characteristic of powders,the optimum rolling reduction is 60%-70%.Cracks and drainage during foaming were inhibited by heat treatment of foaming agent TiH2 and the addition of a certain amount of Mg.The optimum heat treatment way of TiH2 is that heat preserving 1 hour at 450 ℃;the amount of adding Mg is 1wt%.

  19. Advanced powder metallurgy aluminum alloys via rapid solidification technology, phase 2

    Science.gov (United States)

    Ray, Ranjan; Jha, Sunil C.

    1987-01-01

    Marko's rapid solidification technology was applied to processing high strength aluminum alloys. Four classes of alloys, namely, Al-Li based (class 1), 2124 type (class 2), high temperature Al-Fe-Mo (class 3), and PM X7091 type (class 4) alloy, were produced as melt-spun ribbons. The ribbons were pulverized, cold compacted, hot-degassed, and consolidated through single or double stage extrusion. The mechanical properties of all four classes of alloys were measured at room and elevated temperatures and their microstructures were investigated optically and through electron microscopy. The microstructure of class 1 Al-Li-Mg alloy was predominantly unrecrystallized due to Zr addition. Yield strengths to the order of 50 Ksi were obtained, but tensile elongation in most cases remained below 2 percent. The class 2 alloys were modified composition of 2124 aluminum alloy, through addition of 0.6 weight percent Zr and 1 weight percent Ni. Nickel addition gave rise to a fine dispersion of intermetallic particles resisting coarsening during elevated temperature exposure. The class 2 alloy showed good combination of tensile strength and ductility and retained high strength after 1000 hour exposure at 177 C. The class 3 Al-Fe-Mo alloy showed high strength and good ductility both at room and high temperatures. The yield and tensile strength of class 4 alloy exceeded those of the commercial 7075 aluminum alloy.

  20. Advanced powder metallurgy aluminum alloys and composites

    Science.gov (United States)

    Lisagor, W. B.; Stein, B. A.

    1982-01-01

    The differences between powder and ingot metallurgy processing of aluminum alloys are outlined. The potential payoff in the use of advanced powder metallurgy (PM) aluminum alloys in future transport aircraft is indicated. The national program to bring this technology to commercial fruition and the NASA Langley Research Center role in this program are briefly outlined. Some initial results of research in 2000-series PM alloys and composites that highlight the property improvements possible are given.

  1. Preparation and high-temperature oxidation behavior of plasma Cr-Ni alloying on Ti6Al4V alloy based on double glow plasma surface metallurgy technology

    Science.gov (United States)

    Wei, Dong-Bo; Zhang, Ping-Ze; Yao, Zheng-Jun; Wei, Xiang-Fei; Zhou, Jin-Tang; Chen, Xiao-Hu

    2016-12-01

    To improve the oxidation resistance of Ti6Al4V alloy, it was coated with a Cr-Ni alloy with 20, 40, 60, and 80 at.% Ni content using the double-glow plasma surface metallurgy technology. The coatings were dense, uniform, and compact, including a complete structure of deposited layer, interdiffusion layer, and sputtering-affected zone. The effect of Ni content on the isothermal oxidation behavior of coating was investigated at 750, 850, and 950 °C. The results show that the oxide scale consisted of NiO and Cr2O3. The morphology and distribution of NiO in oxide scale were affected by oxidation temperature and Ni content. When the Ni content was ≤40 at.%, the oxidation resistance of the Cr-Ni alloy coating was enhanced.

  2. Annual Report of Institute of Nuclear Chemistry and Technology 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-10-01

    The report is the collection of short communications being the review of the scientific activity of Institute of Nuclear Chemistry and Technology - Warsaw in 1997. The papers are gathered in several branches as follows: radiation chemistry and physics; radiochemistry, stable isotopes, nuclear analytical methods, chemistry in general; radiobiology; nuclear technologies and methods. The annual report of INCT-1997 contains also the general information about INCT as well as the full list of scientific papers being published by the staff in 1997

  3. 77 FR 43131 - Designation of the Center for Innovation and Technology Cooperation (CITC), Pentane Chemistry...

    Science.gov (United States)

    2012-07-23

    ... Designation of the Center for Innovation and Technology Cooperation (CITC), Pentane Chemistry Industries (PCI... of the Center for Innovation and Technology Cooperation (CITC), Pentane Chemistry Industries (PCI... determined that the Center for Innovation and Technology Cooperation (CITC), Pentane Chemistry Industries...

  4. The metallurgy and functional properties of hafnium

    Science.gov (United States)

    Tricot, Roland

    1992-08-01

    Like the two similar elements, titanium and zirconium, hafnium is a young and little known metal whose industrial development began with the nuclear power industry in 1950. After a brief historical survey, the paper describes the specific problems which arise due to the highly specialized chemistry and extractive metallurgy of this metal, dealing with its purification, melting and processing, before going on to review its different applications and discuss future prospects.

  5. Developments in Plasma Processes for Extractive Metallurgy

    Science.gov (United States)

    Gauvin, W. H.; Drouet, M. G.; Munz, R. J.

    1987-12-01

    With the recent availability of commercial plasma-generating devices capable of reliable performance at powers as high as 30 MW, the applications of plasma technology in high-temperature extractive metallurgy are rapidly increasing. Some of the more promising process developments are reviewed in this paper, as are newer reactor designs.

  6. Study on Fe-Based Coating Produced by Plasma Surface Metallurgy

    Institute of Scientific and Technical Information of China (English)

    LI Hui-qi; LIU Bang-wu; LI Hui-dong; ZHANG Li-min; LI Min; SUN Yu-zong

    2004-01-01

    In the paper, plasma surface metallurgy was performed using Fe-based powder on steel substrate. The microstructure and microhardness of the coating have been analyzed. On the base of orthogonal comparison tests,influences of many factors on the cracking sensibility of plasma metallurgy coating have also been studied. The results indicate that substrate and its surface condition, processing parameters and components of plasma metallurgy coating have great effects on cracking sensibility of plasma metallurgy coating. Through changing these factors, it is possible to reduce cracks and promote the applications of this technology.Key Words: plasma surface metallurgy, microstructure, microhardness, cracking sensibility

  7. Institute of Nuclear Chemistry and Technology annual report 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    The report is a collection of short communications being a review of scientific activity of the Institute of Nuclear Chemistry and Technology (INCT), Warsaw, in 1995. The papers are gathered in several branches as follows: radiation chemistry and physics (15); radiochemistry, stable isotopes, nuclear analytical methods, chemistry in general (23); radiobiology (7); nuclear technologies and methods (21); nucleonic control systems (5). The Annual Report of INCT - 1995 contains also a general information about the staff and organization of the Institute, the full list of scientific publications and patents, conferences organized by INCT, thesis and list of projects granted by Polish and international organizations.

  8. Metallurgy, the Father of Materials Science

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The evolution of the discipline of materials science during the second half of the twentieth century is outlined. The concept emerged in the USA, almost simultaneously in an academic metallurgy department and in an avant-garde industrial research laboratory, and its development subsequently all over the world has been a joint enterprise involving universities, industrial laboratories and government establishments. The initial impetus came unambiguously from the well established discipline of physical metallurgy, but from the 1960s onwards, the input from solid-state physicists grew very rapidly, while materials chemistry is a later addition. Of all the many subdivisions of modern materials science, polymer science has been the slowest to fit under the umbrella of the broad discipline; its concepts are very different from those familiar to metallurgists. Two fields have contributed mightily to the creation of modern materials science: One is nuclear energy and, more specifically, the study of radiation damage, the other is the huge field of electronic and opto-electronic materials in which physics, chemistry and metallurgy are seamlessly combined.

  9. Chemistry of nuclear resources, technology, and waste

    Energy Technology Data Exchange (ETDEWEB)

    Keller, O.L. Jr.

    1978-01-01

    Chemistry is being called on today to obtain useful results in areas that have been found very difficult for it in the past, but new instrumentation and new theories are allowing much progress. The area of hydrolytic phenomena and colloid chemistry, as exemplified by the plutonium polymer problem, is clearly entering a new phase in which it can be studied in a much more controlled and understandable manner. The same is true of the little studied interfacial regions, where so much important chemistry occurs in solvent extraction and other systems. The studies of the adsorption phenomena on clays are an illustration of the new and useful modeling of geochemical phenomena that is now possible. And finally, the chemist is called upon to participate in the developement and evaluation of models for nuclear waste isolation requiring extrapolations of hundreds to hundreds of thousands of years into the future. It is shown that chemistry may be useful in keeping the extrapolations in the shorter time spans, and also in selecting the best materials for containment. 36 figures.

  10. [Methodological approaches to the development of environmentally benign technology for the use of solid waste in iron metallurgy].

    Science.gov (United States)

    Pugin, K G; Vaĭsman, Ia I

    2013-01-01

    On the basis of the life cycle of materials, containing wastes of iron and steel industry, new methodological approaches to the assessment of technologies of the secondary use of wastes are developed A complex criteria for selection of the technology for the use of resource potential of solid waste of iron and steel industry are developed with taking into account environmental, technological and economic indices. The technology of the use of wastes of ferrovanadium industry as bulk solid materials at the solid waste landfill is shown.

  11. Study of the mechanical stability and bioactivity of Bioglass(®) based glass-ceramic scaffolds produced via powder metallurgy-inspired technology.

    Science.gov (United States)

    Boccardi, Elena; Melli, Virginia; Catignoli, Gabriele; Altomare, Lina; Jahromi, Maryam Tavafoghi; Cerruti, Marta; Lefebvre, Louis-Philippe; De Nardo, Luigi

    2016-02-02

    Large bone defects are challenging to heal, and often require an osteoconductive and stable support to help the repair of damaged tissue. Bioglass-based scaffolds are particularly promising for this purpose due to their ability to stimulate bone regeneration. However, processing technologies adopted so far do not allow for the synthesis of scaffolds with suitable mechanical properties. Also, conventional sintering processes result in glass de-vitrification, which generates concerns about bioactivity. In this work, we studied the bioactivity and the mechanical properties of Bioglass(®) based scaffolds, produced via a powder technology inspired process. The scaffolds showed compressive strengths in the range of 5-40 MPa, i.e. in the upper range of values reported so far for these materials, had tunable porosity, in the range between 55 and 77%, and pore sizes that are optimal for bone tissue regeneration (100-500 μm). We immersed the scaffolds in simulated body fluid (SBF) for 28 d and analyzed the evolution of the scaffold mechanical properties and microstructure. Even if, after sintering, partial de-vitrification occurred, immersion in SBF caused ion release and the formation of a Ca-P coating within 2 d, which reached a thickness of 10-15 μm after 28 d. This coating contained both hydroxyapatite and an amorphous background, indicating microstructural amorphization of the base material. Scaffolds retained a good compressive strength and structural integrity also after 28 d of immersion (6 MPa compressive strength). The decrease in mechanical properties was mainly related to the increase in porosity, caused by its dissolution, rather than to the amorphization process and the formation of a Ca-P coating. These results suggest that Bioglass(®) based scaffolds produced via powder metallurgy-inspired technique are excellent candidates for bone regeneration applications.

  12. Surface chemistry: Key to control and advance myriad technologies

    Science.gov (United States)

    Yates, John T.; Campbell, Charles T.

    2011-01-01

    This special issue on surface chemistry is introduced with a brief history of the field, a summary of the importance of surface chemistry in technological applications, a brief overview of some of the most important recent developments in this field, and a look forward to some of its most exciting future directions. This collection of invited articles is intended to provide a snapshot of current developments in the field, exemplify the state of the art in fundamental research in surface chemistry, and highlight some possibilities in the future. Here, we show how those articles fit together in the bigger picture of this field. PMID:21245359

  13. JPRS Report, Science & Technology, USSR: Chemistry

    Science.gov (United States)

    1990-12-28

    UCH-90-014 28 December 1990 2 USSR: Chemistry Increasing Heat Transfer Efficiency in LiBr Absorption Refrigerating Machine [A. V. Baranenko, V. M...Efficiency in LiBr Absorption Refrigerating Machine 917M0010B Moscow KH1M1CHESKOYEI NEFTYANOYE MASHINOSTROYENIYE in Russian No 9, Sep 90 pp 16-18... machine by 20-25%. When this is done, however, it is necessary to furnish the refrigerating machine with a special device to circulate the isooctanol

  14. Annual report of Institute of Nuclear Chemistry and Technology 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-01

    The report is a collection of short communications being a review of the scientific activities of the Institute of Nuclear Chemistry and Technology, Warsaw in 1996. The papers are gathered in several branches as follows: radiation chemistry and physics (17); Radiochemistry, stable isotopes, nuclear analytical methods,chemistry in general (20); radiobiology (9); nuclear technologies and methods (28).The last and biggest chapter has been divided in four smaller groups; process engineering; material engineering,structural studies,diagnostics; radiation technologies; nucleonic control systems. The annual report of INCT-1996 contains also a general information of Institute, the full list of scientific publications and patents, conferences organized by INCT, Ph.D. and D.Sc. thesis, a list of projects granted by Polish Committee of Scientific Research and other organizations.

  15. Sustainable technological development in chemistry. Improving the quality of life through chemistry and agriculture

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-08-01

    The importance of agricultural products, their potential conversion to energy sources and their applications for fibre-reinforced construction materials is emphasized. Another potentially important technology is the conversion of sunlight into electricity such as occurs in the leaves of plants. Parallels with nature exist, even though conversions with inorganic materials have, until now, been promising. The ability to control chemical reactions is the subject throughout all the following chapters. The goal is to achieve high reaction efficiencies and to use fewer basic materials, both of which will lead to a reduction in environmental stress. Sustainable developments in chemistry can be described by two approaches: (1) Improvements in society, with challenges for chemistry; and (2) Improvement in the chemical sector itself. Both approaches are dealt with in this report. Five areas for development have been chosen in the discussions for `DTO-Chemie`: Integrated plant conversion (IPC), in particular Valorisation of plant parts for raw materials and energy; Biomass conversion (C1 Chemistry), in particular Technologies for (among others) C1-based chemicals and energy carriers; Photovoltaic cells (PSC), in particular Technologies for the conversion of solar light into electricity; Process Technology in Fine chemistry (PFC), in particular Methodology of manufacturing processes for Fine chemicals; and Sustainable Construction Materials (FRC); in particular Techniques for using fibre-reinforced composites in construction applications. These areas can be viewed as clusters of technologies, with a strong chemistry and agricultural component, which are necessary for achieving a sustainable future. Furthermore, it is important to recognise that technology requires a progressive development (technology lifecycle). The five areas of technology development are tested against a number of criteria: (1) Sustainability / leap / volume; (2) Horizon 2050; (3) Commitment from industry

  16. JPRS Report, Science & Technology, USSR: Chemistry.

    Science.gov (United States)

    2007-11-02

    technology of partial briquetting purchased from Japan. The money was considerable. And the prokuto [?]? This method requires a binder, which is not...allocated for the development of new coking technologies, the lion*s share has been allotted for partial briquetting and ramming. And only 18.2

  17. Handbook of green chemistry and technology

    Energy Technology Data Exchange (ETDEWEB)

    Clark, J.; MacQuarrie, D. (eds.)

    2002-05-15

    Sustainable development is now accepted as a necessary goal for achieving societal, economic and environmental objectives. Within this chemistry has a vital role to play. The chemical industry is successful but traditionally success has come at a heavy cost to the environment. The challenge for chemists and others is to develop new products, processes and services that achieve societal, economic and environmental benefits. This requires an approach that reduces the materials and energy intensity of chemical processes and products; minimises the dispersion of harmful chemicals in the environment; maximises the use of renewable resources and extends the durability and recyclability of products in a way that increases industrial competitiveness as well as improve its tarnished image. (author)

  18. Institute of Nuclear Chemistry and Technology annual report 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    This annual report is a collection of short communications being a review of scientific activity of the Institute of Nuclear Chemistry and Technology, Warsaw, Poland in 1994. The papers are gathered into several branches as follows: radiation chemistry and physics (16 papers); radiochemistry, stable isotopes, nuclear analytical methods, chemistry in general (17 papers); radiobiology (6 papers); nuclear technologies and methods (30 papers). The annual report of INCT-1994 contains also a general information about the Institute, the full list of papers published in 1994, information about Nukleonika - the International Journal of Nuclear Research being edited in INCT, the list of patent granted and patent applications in 1994, information about conferences organized by the Institute, the list of Ph.D. and D.Sc. finished in 1994 as well as the list of research projects and contracts being realized in INCT during 1994.

  19. Integrating Webinar and Blogging Technologies into Chemistry Seminar

    Science.gov (United States)

    Hamstra, Dan; Kemsley, Jyllian N.; Murray, Desmond H.; Randall, David W.

    2011-01-01

    We report successfully integrating webinar and blogging into an undergraduate chemistry and biochemistry seminar course. Commercial collaboration software linked speaker-operated slides with two-way voice and video effectively connecting the audience and presenter from different states. Student responses to the technology and seminar content were…

  20. Contextualization and technologies in the Biology and Chemistry textbooks

    Directory of Open Access Journals (Sweden)

    Rozana Gomes de Abreu

    2005-12-01

    Full Text Available We analyze Biology and Chemistry school textbooks to understand how conceptions of contextualization and technologies are overtaken and hybridized. We consider that textbooks produce meanings (senses and signifieds in curricular policies. These are cultural productions that were hybridized and recontextualized according to Basil Bernstein and Stephen Ball. We argue that the focus on contextualization and technologies expressed in those textbooks are hybridized from several influences and they do not represent a consensus about those conceptions.

  1. A Laboratory Course in Technological Chemistry.

    Science.gov (United States)

    Wiseman, P.

    1986-01-01

    Describes a laboratory course taught at the University of Manchester Institute of Science and Technology (United Kingdom) which focuses on the preparation, properties, and applications of end-use products of the chemical industry. Outlines laboratory experiments on dyes, fibers, herbicides, performance testing, antioxidants, and surface active…

  2. Cardamom--production, technology, chemistry, and quality.

    Science.gov (United States)

    Govindarajan, V S; Narasimhan, S; Raghuveer, K G; Lewis, Y S

    1982-01-01

    Cardamom, Elettaria cardamomum Maton var. Miniscula Burkill (Fam. Zingiberaceae) known as true or lesser cardamom is the widely cultivated variety and important in the world trade. It occupies a high second or third place in world trade, being a high priced spice. It belongs to the sweet spices group and is used predominantly to flavor sweets, baked goods, and coffee, particularly in the Arab countries. This monograph critically reviews the post-harvest handling and processing and the chemistry of the volatiles. The components contributing to the characteristic aroma for which the spice is valued are specifically considered. Gas chromatographic analysis for quality control and attempts are evaluating the aroma quality by sensory profile are discussed in relation to regional varieties, and processing variables. The areas in which further research is required are indicated. The botanical and cultivation aspects and production and trade of the different growing and consuming regions are briefly considered. Available information on other "cardamoms" from related species and genera are summarized.

  3. Turmeric--chemistry, technology, and quality.

    Science.gov (United States)

    Govindarajan, V S

    1980-01-01

    Turmeric is a minor spice in the West, but a major one in the East. It is valued by Westerners mainly, if not solely, on account of its color, but to the Asians both color and aroma are equally important. This review critically appraises the existing knowledge on the chemistry of the functionally important constituents, the processing of the spice into wholes, powder, and oleoresins, and the objective methods and standards available for evaluation of quality. The importance of the mild (but persistent) aroma, and the lack of detailed knowledge on the significant volatiles are discussed. Some unpublished data on significant aroma components, a tristimulus study of color, and subjective evaluations of quality are summarized. Other areas briefly discussed are the production and trade, curry powder, allied spices, and biosynthetic and physiological aspects. The confusion existing in the literature on the nomenclature of species included in the genus Curcuma is pointed out. In view of the growing importance of turmeric and its extracts as a natural food color, recent results on toxicological aspects are discussed. The areas in which research is needed are indicated at the end.

  4. Chemistry Progress and Civilization in Ancient China

    Institute of Scientific and Technical Information of China (English)

    JIANG Yu-Qian; RUAN Shu-Xiang; TANG Shan; SHUAI Zhi-Gang

    2011-01-01

    @@ During the 6,000 years of Chinese civilization, chemistry has played an essential role.The bronzed chime bells of the Warring States Period (475-221 BC) unearthed in Hubei Province shows not only the excellence in musical instruments in ancient China, but also the technological advances in metallurgy.Chinese alchemy was not originated from the quest to turn common metals to gold, instead, it was for searching medicines for longevity of human beings, mostly practised by Taoists.

  5. JPRS Report, Science & Technology USSR: Chemistry

    Science.gov (United States)

    2007-11-02

    74 hours with a current of 200-300 mA/cm2 in 1 M LiOH and KOH solutions followed by extraction of the alkali metal with water. In the first case...oxides of sulfur and nitrogen from off gases, heavy metal ions and ammonia from industrial wastes, and to dry air and natural gas. Leaching cesium...for this reason costly inorganic ion exchange methods are used to extract rare alkali metals . One of the most pressing prob- lems of water technology

  6. Applications of physical chemistry to glass technology

    Science.gov (United States)

    Stewart, Ogie Gregory

    2001-07-01

    Industrial manufacturing of glass, called float glass, involves a process in which flat pieces of glass are produced by pouring molten glass on a bath of molten tin metal. The glass is then coated with thin film coatings for such applications as solar radiation control and "privacy" glass. In this thesis, principles of physical chemistry are applied to selected aspects of glass production and thin film coatings in an effort to better understand these processes with the hope of improving film and glass quality. The research described here consists of three major studies. Part 1 describes the production of thin films by Atmospheric Pressure Chemical Vapor Deposition (APCVD) and characterization of the films by various analytical techniques. Vanadium oxide films were produced from vanadium (IV) chloride and each of several alcohols to determine the feasibility of this method of deposition and to investigate its use in an electrochromic device. The focus here was to investigate the levels of carbon contamination in the films. It was found that the level of carbon present in the films depend on the type of amine used. Part 2 is an investigation of the flow dynamics that occur during the two thin film deposition processes. APCVD and Powder Spray Pyrolysis (PSP). Information regarding flow dynamics and particle distribution in the region above the films' substrates were obtained and related to film formation and quality. Part 3 is a kinetic study of the gas phase reactions that occur in the vapor region above the glass during float glass production. A kinetic model of the possible reactions was devised and integrated to predict the formation of these impurities with time. An experimental setup to test the model's predictions is also discussed. The research described in this thesis lays the groundwork for several possibilities for future work. Electrochromic films can be produced by APCVD to construct an all-solid-state device. Two dimensional imaging coupled with Laser

  7. Citrus fruits--varieties, chemistry, technology, and quality evaluation. Part II. Chemistry, technology, and quality evaluation. A. Chemistry.

    Science.gov (United States)

    Ranganna, S; Govindarajan, V S; Ramana, K V

    1983-01-01

    In Part 2 of this review on citrus fruits, the literature on chemistry, technology, and quality evaluation are critically considered. Sweet oranges, mandarin, grapefruit, lemon, and lime are generally used for processing. The literature on chemical components of citrus fruit which include sugars, polysaccharides, oraganic acids, nitrogenous constituents and lipids; carotenoids which contribute to color; vitamins and minerals, and flavonoids; limonoids, some of which impart bitterness to the juice; and the volatile components which contribute to aroma have been reviewed. Chilled and pasteurized juices, juice concentrates, and beverages are the important products manufactured commercially, and to a limited extent powdered citrus juices, canned segments, and marmalades. The literature on the manufacture of these products also as new types of juice and oil extractors; TASTE and other types of evaporators; tank farms to store juice and concentrate in bulk; aseptic filling in bulk containers and retail packs; alternate flexible and rigid containers other than glass and tin; and recovery of volatile flavoring constituents during juice processing are some of the important technological developments in the recent past and have been discussed. Bitterness in citrus juices and its control, composition of cloud, and its stability and changes during storage have been reviewed. Essential oils, pectin, frozen and dried juice sacs, dried pulp and molasses, flavonoids, seed oil, and meal are the important byproducts, the manufacture of which is given in essential details. Generally, consumers judge the product on the basis of its sensory attributes. The quality of finished product is dependent upon the raw materials used and control of processes. The U.S. Department of Agriculture (USDA) standards for different products, physicochemical and microbiological parameters prescribed as indices of quality of fruit, juice, concentrate, and other products; composition of essential oils; and

  8. Study on Fe-Based Coating Produced by Plasma Surface Metallurgy

    Institute of Scientific and Technical Information of China (English)

    LIHui-qi; LIUBang-wu; LIHui-dong; ZHANGLi-min; LIMin; SUNYu-zong

    2004-01-01

    In the paper, plasma surface metallurgy was performed using Fe-based powder on steel substrate. The microstructure and microhardness of the coating have been analyzed. On the base of orthogonal comparison tests, influences of many factors on the cracking sensibility of plasma metallurgy coating have also been studied. The results indicate that substrate and its surface condition, processing parameters and components of plasma metallurgy coating have great effects on cracking sensibility of plasma metallurgy coating. Through changing these factors, it is possible to reduce cracks and promote the applications of this technology.

  9. Pressurized metallurgy for high performance special steels and alloys

    Science.gov (United States)

    Jiang, Z. H.; Zhu, H. C.; Li, H. B.; Li, Y.; Liu, F. B.

    2016-07-01

    The pressure is one of the basic parameters which greatly influences the metallurgical reaction process and solidification of steels and alloys. In this paper the history and present situation of research and application of pressurized metallurgy, especially pressurized metallurgy for special steels and alloys have been briefly reviewed. In the following part the physical chemistry of pressurized metallurgy is summarized. It is shown that pressurizing may change the conditions of chemical reaction in thermodynamics and kinetics due to the pressure effect on gas volume, solubility of gas and volatile element in metal melt, activity or activity coefficient of components, and change the physical and chemical properties of metal melt, heat transfer coefficient between mould and ingot, thus greatly influencing phase transformation during the solidification process and the solidification structure, such as increasing the solidification nucleation rate, reducing the critical nucleation radius, accelerating the solidification speed and significant macro/micro-structure refinement, and eliminating shrinkage, porosity and segregation and other casting defects. In the third part the research works of pressured metallurgy performed by the Northeastern University including establishment of pressurized induction melting (PIM) and pressurized electroslag remelting (PESR) equipments and development of high nitrogen steels under pressure are described in detail. Finally, it is considered in the paper that application of pressurized metallurgy in manufacture of high performance special steels and alloys is a relatively new research area, and its application prospects will be very broad and bright.

  10. Materials, Chemistry, and Simulation for Future Energy Technology.

    Science.gov (United States)

    Aguey-Zinsou, Kondo-Francois; Wang, Da-Wei; Su, Dang-Sheng

    2015-09-01

    Special Issue: The Future of Energy. The science and engineering of clean energy now is becoming a multidisciplinary area, typically when new materials, chemistry, or mechanisms are met. "Trial and error" is the past. Exploration of new concepts for future clean energy can be accomplished through computer-aided materials design and reaction simulation, thanks to innovations in information technologies. This special issue, a fruit of the Energy Future Conference organized by UNSW Australia, has compiled some excellent examples of such approaches.

  11. Contribution of microreactor technology and flow chemistry to the development of green and sustainable synthesis.

    Science.gov (United States)

    Fanelli, Flavio; Parisi, Giovanna; Degennaro, Leonardo; Luisi, Renzo

    2017-01-01

    Microreactor technology and flow chemistry could play an important role in the development of green and sustainable synthetic processes. In this review, some recent relevant examples in the field of flash chemistry, catalysis, hazardous chemistry and continuous flow processing are described. Selected examples highlight the role that flow chemistry could play in the near future for a sustainable development.

  12. Contribution of microreactor technology and flow chemistry to the development of green and sustainable synthesis

    Directory of Open Access Journals (Sweden)

    Flavio Fanelli

    2017-03-01

    Full Text Available Microreactor technology and flow chemistry could play an important role in the development of green and sustainable synthetic processes. In this review, some recent relevant examples in the field of flash chemistry, catalysis, hazardous chemistry and continuous flow processing are described. Selected examples highlight the role that flow chemistry could play in the near future for a sustainable development.

  13. MODERN INNOVATIVE PEDAGOGICAL TECHNOLOGY FOR PROFILE SCHOOL CHEMISTRY LESSONS

    Directory of Open Access Journals (Sweden)

    Maria D. Tukalo

    2011-10-01

    Full Text Available The article gives a characteristic of modern innovative pedagogical technologies with methods of their use in chemistry lessons at school it reveals their importance in the learning process to optimize the learning and the knowledge and skills to apply them to solve specific problems of scientific opinion, enhance the creative activity of transition cognitive motivation of the professional through the establishment of conditions for development of the creative potential of students using computer-oriented learning means within a modern educational system in order to fulfill the basic educational goals: developing, information, mobilization, communication, research.

  14. Extractive Metallurgy Program funded

    Science.gov (United States)

    Bell, Peter M.

    In an effort to concentrate research on ore dressing and metal production, the National Science Foundation (NSF) formed a new basic research program as a part of its Chemical and Process Engineering Division. This program will be under the auspices of NSF's Engineering Directorate. Research is to be supported on every step of extractive metallurgy, from mining to processing to production, and even to reprocessing and disposal. Budgeting for the new program is expected to be on the order of $1.2 million for fiscal year 1981.A program of this nature was apparently considered seriously by the Carter administration as a joint Department of Interior-private industry project of considerable size. Then-Secretary of Interior Cecil Andrus evidently did not support the program, but there is wide agreement throughout the mineral industries and the university community that such research is badly needed for the U.S. to compete. A joint program could benefit by cutting across the many difficult regulations that now are blamed for slowing research in minerals processing in this country.

  15. Plasma enhanced C1 chemistry for green technology

    Science.gov (United States)

    Nozaki, Tomohiro

    2013-09-01

    Plasma catalysis is one of the innovative next generation green technologies that meet the needs for energy and materials conservation as well as environmental protection. Non-thermal plasma uniquely generates reactive species independently of reaction temperature, and these species are used to initiate chemical reactions at unexpectedly lower temperatures than normal thermochemical reactions. Non-thermal plasma thus broadens the operation window of existing chemical conversion processes, and ultimately allows modification of the process parameters to minimize energy and material consumption. We have been specifically focusing on dielectric barrier discharge (DBD) as one of the viable non-thermal plasma sources for practical fuel reforming. In the presentation, room temperature one-step conversion of methane to methanol and hydrogen using a miniaturized DBD reactor (microplasma reactor) is highlighted. The practical impact of plasma technology on existing C1-chemistry is introduced, and then unique characteristics of plasma fuel reforming such as non-equilibrium product distribution is discussed.

  16. Iron Metallurgy: Technical Terminology Bulletin. Terminotech, Vol. 2, No. 7.

    Science.gov (United States)

    General Electric Co. of Canada, Ltd., Montreal, Quebec.

    This issue of a bulletin of technological terminology is devoted to iron metallurgy. Various aspects of iron production are described in both French and English. An English-French dictionary of terms comprises the bulk of the document. Explanatory illustrations are appended. (JB)

  17. The extractive metallurgy of gold

    Science.gov (United States)

    Kongolo, K.; Mwema, M. D.

    1998-12-01

    Mössbauer spectroscopy has been successfully used in investigation of the gold compounds present in ores and the gold species which occur during the process metallurgy of this metal. This paper is a survey of the basic recovery methods and techniques used in extractive metallurgy of gold. Process fundamentals on mineral processing, ore leaching, zinc dust cementation, adsorption on activated carbon, electrowinning and refining are examined. The recovery of gold as a by-product of the copper industry is also described. Alternative processing methods are indicated in order to shed light on new interesting research topics where Mössbauer spectroscopy could be applied.

  18. Physical metallurgy of nickel aluminides

    Indian Academy of Sciences (India)

    G K Dey

    2003-02-01

    A description of the important physical metallurgy aspects of Ni$_3Al and NiAl encompassing structure, crystallographic defects, slip systems and phase stability has been presented in this article. The microstructures generated in the two alloys by conventional as well as novel processing techniques have been discussed. The effect of alloying additions on the microstructure has been enumerated. Besides description of the aforementioned physical metallurgy aspects, an important purpose of this review is to focus on the reasons of brittleness in the two alloys and means of alleviating this problem primarily by alloying. The effect of alloying on the slip behaviour has also been described.

  19. Chemistry and technology of Cured and Smoked Meat Products

    Directory of Open Access Journals (Sweden)

    V. K. Mathur

    1967-05-01

    Full Text Available Recent developments in the chemistry and technology of cured and smoked meat products are reviewed. Various factors physical, chemical and microbiological affecting water holding capacity of cured meats and cured colour formation and its stability during storage are discussed. Methods of preparation of various types of cured and smoked meat products have been briefly described. Developments in the use of synthetic casings and skinless sausages have been mentioned. Smoke constituents, their role and physico-chemical aspects of mechanism and functions of smoking are discussed. Advancements in the methods of smoke generation, conventional smoking and some kilns, electrostatic smoking and smoking by use of liquid smokes have been described. Some of the methods of preparation of liquid smokes are also given.

  20. Lubricant Biodegradation Enhancers:Designed Chemistry and Engineered Technology

    Institute of Scientific and Technical Information of China (English)

    Chen Boshui; Gao Lingyue; Fang Jianhua; Zhang Nan; Wu Jiang; Wang Jiu

    2015-01-01

    In recent decades, a growing worldwide trend of developing the biodegradable lubricants has been prevailing to form a speciifc ifeld of green chemistry and green engineering. Enhancement of biodegradability of unreadily biodegradable petroleum-based lubricants has as such become an urgent must. For over a decade the authors have been focusing on the im-provement of biodegradability of unreadily biodegradable lubricants such as petroleum-based lubricating oils and greases. A new idea of lubricant biodegradation enhancer was put forward by the authors with the aim to stimulate the biodegradation of unreadily biodegradable lubricants by incorporating the enhancer into the lubricants in order to turn the lubricants into greener biodegradable ones and to help in situ bioremediation of lubricant-contaminated environment. This manuscript sum-marizes our recent efforts relating to the chemistry and technology of biodegradation enhancers for lubricants. Firstly, the chemistry of lubricant biodegradation enhancers was designed based on the principles of bioremediation for the treatment of hydrocarbon contaminated environment. Secondly, the ability of the designed biodegradation enhancers for increasing the biodegradability of unreadily biodegradable industrial lubricants was investigated through biodegradability evaluation tests, microbial population analysis, and biodegradation kinetics modeling. Finally, the impact of biodegradation enhancers on some crucial performance characteristics of lubricants such as lubricity and oxidation stability was tested via tribological evaluation and oxidation determinations. Our results have shown that the designed chemistry of nitrogenous and/or phos-phorous compounds such as lauroyl glutamine, oleoyl glycine, oleic diethanolamide phosphate and lauric diethanolamide borate was outstanding in boosting biodegradation of petroleum-based lubricants which was ascribed to increase the micro-bial population and decrease the oil-water interfacial

  1. International standards in metallurgy

    Institute of Scientific and Technical Information of China (English)

    Fomina; O.; N.

    2005-01-01

    The existence of incompatible standards in many technical fields represents a technical barrier to international cooperation between enterprises in different countries in the manufacture of high technology products.……

  2. Recent trends in extractive metallurgy

    Science.gov (United States)

    Bell, Peter M.

    Metallurgists and solution geochemists are joining forces to develop processes for extraction of metals from low-grade ores. The processes, which come under the name hydrometallurgy, include several new applications of solvent extraction techniques. Aqueous solutions are employed, leaching metals from ores, mine waste dumps, and even from deposits still in the ground. It was notable, for example, that Chemical and Engineering News (Feb. 8, 1982) recently featured the subject of hydrometallurgy in a special report. They noted that ‘recovering metals by use of aqueous solutions at relatively low temperatures increasingly is competing with dry, high-temperature pyrometallurgical methods.’ The relatively new techniques have caused a revolution, of sorts, in engineering programs of university metallurgy departments. The challenge of developing selective metal dissolution processes is drawing upon the best national talent in the fields of solution geochemistry and metallurgy.

  3. Aluminum powder metallurgy processing

    Energy Technology Data Exchange (ETDEWEB)

    Flumerfelt, J.F.

    1999-02-12

    The objective of this dissertation is to explore the hypothesis that there is a strong linkage between gas atomization processing conditions, as-atomized aluminum powder characteristics, and the consolidation methodology required to make components from aluminum powder. The hypothesis was tested with pure aluminum powders produced by commercial air atomization, commercial inert gas atomization, and gas atomization reaction synthesis (GARS). A comparison of the GARS aluminum powders with the commercial aluminum powders showed the former to exhibit superior powder characteristics. The powders were compared in terms of size and shape, bulk chemistry, surface oxide chemistry and structure, and oxide film thickness. Minimum explosive concentration measurements assessed the dependence of explosibility hazard on surface area, oxide film thickness, and gas atomization processing conditions. The GARS aluminum powders were exposed to different relative humidity levels, demonstrating the effect of atmospheric conditions on post-atomization processing conditions. The GARS aluminum powders were exposed to different relative humidity levels, demonstrating the effect of atmospheric conditions on post-atomization oxidation of aluminum powder. An Al-Ti-Y GARS alloy exposed in ambient air at different temperatures revealed the effect of reactive alloy elements on post-atomization powder oxidation. The pure aluminum powders were consolidated by two different routes, a conventional consolidation process for fabricating aerospace components with aluminum powder and a proposed alternative. The consolidation procedures were compared by evaluating the consolidated microstructures and the corresponding mechanical properties. A low temperature solid state sintering experiment demonstrated that tap densified GARS aluminum powders can form sintering necks between contacting powder particles, unlike the total resistance to sintering of commercial air atomization aluminum powder.

  4. REVIEW OF RECENT DEVELOPMENTS: POWER METALLURGY,

    Science.gov (United States)

    REVIEWS), (*POWDER METALLURGY, CASTING, SINTERING, COOLING, CUTTING TOOLS , TUNGSTEN ALLOYS, PIPES, DISPERSION HARDENING, NICKEL ALLOYS, COBALT ALLOYS, THORIUM COMPOUNDS, OXIDES, BERYLLIUM, POWDER ALLOYS.

  5. Current status and future prospects for enabling chemistry technology in the drug discovery process

    Science.gov (United States)

    Djuric, Stevan W.; Hutchins, Charles W.; Talaty, Nari N.

    2016-01-01

    This review covers recent advances in the implementation of enabling chemistry technologies into the drug discovery process. Areas covered include parallel synthesis chemistry, high-throughput experimentation, automated synthesis and purification methods, flow chemistry methodology including photochemistry, electrochemistry, and the handling of “dangerous” reagents. Also featured are advances in the “computer-assisted drug design” area and the expanding application of novel mass spectrometry-based techniques to a wide range of drug discovery activities. PMID:27781094

  6. Current status and future prospects for enabling chemistry technology in the drug discovery process

    OpenAIRE

    Djuric, Stevan W.; Hutchins, Charles W; Talaty, Nari N.

    2016-01-01

    This review covers recent advances in the implementation of enabling chemistry technologies into the drug discovery process. Areas covered include parallel synthesis chemistry, high-throughput experimentation, automated synthesis and purification methods, flow chemistry methodology including photochemistry, electrochemistry, and the handling of “dangerous” reagents. Also featured are advances in the “computer-assisted drug design” area and the expanding application of novel mass spectrometry-...

  7. Guidelines for Chemistry and Chemical Technology Programs in Two-Year Colleges.

    Science.gov (United States)

    American Chemical Society, Washington, DC.

    Designed for use in institutional self-studies and program reviews, these guidelines provide a comprehensive model for chemistry and chemical technology programs in two-year, associate-degree-granting colleges. The eight sections of the guide suggest 90 standards in the areas of: (1) chemistry program mission and periodic program review; (2)…

  8. Research on the development of green chemistry technology assessment techniques: a material reutilization case

    Science.gov (United States)

    Hong, Seokpyo; Ahn, Kilsoo; Kim, Sungjune; Gong, Sungyong

    2015-01-01

    Objectives This study presents a methodology that enables a quantitative assessment of green chemistry technologies. Methods The study carries out a quantitative evaluation of a particular case of material reutilization by calculating the level of “greenness” i.e., the level of compliance with the principles of green chemistry that was achieved by implementing a green chemistry technology. Results The results indicate that the greenness level was enhanced by 42% compared to the pre-improvement level, thus demonstrating the economic feasibility of green chemistry. Conclusions The assessment technique established in this study will serve as a useful reference for setting the direction of industry-level and government-level technological R&D and for evaluating newly developed technologies, which can greatly contribute toward gaining a competitive advantage in the global market. PMID:26206363

  9. Research on the development of green chemistry technology assessment techniques: a material reutilization case.

    Science.gov (United States)

    Hong, Seokpyo; Ahn, Kilsoo; Kim, Sungjune; Gong, Sungyong

    2015-01-01

    This study presents a methodology that enables a quantitative assessment of green chemistry technologies. The study carries out a quantitative evaluation of a particular case of material reutilization by calculating the level of "greenness" i.e., the level of compliance with the principles of green chemistry that was achieved by implementing a green chemistry technology. The results indicate that the greenness level was enhanced by 42% compared to the pre-improvement level, thus demonstrating the economic feasibility of green chemistry. The assessment technique established in this study will serve as a useful reference for setting the direction of industry-level and government-level technological R&D and for evaluating newly developed technologies, which can greatly contribute toward gaining a competitive advantage in the global market.

  10. Silicon solar cells: Physical metallurgy principles

    Science.gov (United States)

    Mauk, Michael G.

    2003-05-01

    This article reviews the physical metallurgy aspects of silicon solar cells. The production of silicon solar cells relies on principles of thermochemical extractive metallurgy, phase equilibria, solidification, and kinetics. The issues related to these processes and their impact on solar cell performance and cost are discussed.

  11. Effects of '"Environmental Chemistry" Elective Course via Technology-Embedded Scientific Inquiry Model on Some Variables

    Science.gov (United States)

    Çalik, Muammer; Özsevgeç, Tuncay; Ebenezer, Jazlin; Artun, Hüseyin; Küçük, Zeynel

    2014-01-01

    The purpose of this study is to examine the effects of "environmental chemistry" elective course via Technology-Embedded Scientific Inquiry (TESI) model on senior science student teachers' (SSSTs) conceptions of environmental chemistry concepts/issues, attitudes toward chemistry, and technological pedagogical content knowledge…

  12. Effects of '"Environmental Chemistry" Elective Course via Technology-Embedded Scientific Inquiry Model on Some Variables

    Science.gov (United States)

    Çalik, Muammer; Özsevgeç, Tuncay; Ebenezer, Jazlin; Artun, Hüseyin; Küçük, Zeynel

    2014-01-01

    The purpose of this study is to examine the effects of "environmental chemistry" elective course via Technology-Embedded Scientific Inquiry (TESI) model on senior science student teachers' (SSSTs) conceptions of environmental chemistry concepts/issues, attitudes toward chemistry, and technological pedagogical content knowledge…

  13. Powder Metallurgy Fabrication of Molybdenum Accelerator Target Disks

    Energy Technology Data Exchange (ETDEWEB)

    Lowden, Richard Andrew [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kiggans Jr., James O. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Nunn, Stephen D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Parten, Randy J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-07-01

    Powder metallurgy approaches for the fabrication of accelerator target disks are being examined to support the development of Mo-99 production by NorthStar Medical Technologies, LLC. An advantage of powder metallurgy is that very little material is wasted and, at present, dense, quality parts are routinely produced from molybdenum powder. The proposed targets, however, are thin wafers, 29 mm in diameter with a thickness of 0.5 mm, with very stringent dimensional tolerances. Although tooling can be machined to very high tolerance levels, the operations of powder feed, pressing and sintering involve complicated mechanisms, each of which affects green density and shrinkage, and therefore the dimensions and shape of the final product. Combinations of powder morphology, lubricants and pressing technique have been explored to produce target disks with minimal variations in thickness and little or no distortion. In addition, sintering conditions that produce densities for optimum target dissolvability are being determined.

  14. Powder Metallurgy Fabrication of Molybdenum Accelerator Target Disks

    Energy Technology Data Exchange (ETDEWEB)

    Lowden, Richard Andrew [ORNL; Kiggans Jr, James O [ORNL; Bryan, Chris [ORNL; Nunn, Stephen D [ORNL; Parten, Randy J [ORNL

    2015-12-01

    Powder metallurgy approaches for the fabrication of accelerator target disks are being examined to support the development of Mo-99 production by NorthStar Medical Technologies, LLC. An advantage of powder metallurgy is that very little material is wasted and at present, dense, quality parts are routinely produced from molybdenum powder. The proposed targets, however, are thin wafers, 29 mm in diameter with a thickness of 0.5 mm, with very stringent dimensional tolerances. Although tooling can be machined to very high tolerance levels, the operations of powder feed, pressing and sintering involve complicated mechanisms, each of which affects green density and shrinkage, and therefore the dimensions and shape of the final product. Combinations of powder morphology, lubricants and pressing technique have been explored to produce target disks with minimal variations in thickness and little or no distortion. In addition, sintering conditions that produce densities for optimum target dissolvability are being determined.

  15. Learning How to Teach Chemistry with Technology: Pre-Service Teachers' Experiences with Integrating Technology into Their Learning and Teaching

    Science.gov (United States)

    Chittleborough, Gail

    2014-01-01

    The Australian Government initiative, Teaching Teachers for the Future (TTF), was a targeted response to improve the preparation of future teachers with integrating technology into their practice. This paper reports on TTF research involving 28 preservice teachers undertaking a chemistry curriculum studies unit that adopted a technological focus.…

  16. Priority survey between indicators and analytic hierarchy process analysis for green chemistry technology assessment

    Science.gov (United States)

    Kim, Sungjune; Hong, Seokpyo; Ahn, Kilsoo; Gong, Sungyong

    2015-01-01

    Objectives This study presents the indicators and proxy variables for the quantitative assessment of green chemistry technologies and evaluates the relative importance of each assessment element by consulting experts from the fields of ecology, chemistry, safety, and public health. Methods The results collected were subjected to an analytic hierarchy process to obtain the weights of the indicators and the proxy variables. Results These weights may prove useful in avoiding having to resort to qualitative means in absence of weights between indicators when integrating the results of quantitative assessment by indicator. Conclusions This study points to the limitations of current quantitative assessment techniques for green chemistry technologies and seeks to present the future direction for quantitative assessment of green chemistry technologies. PMID:26206364

  17. Priority survey between indicators and analytic hierarchy process analysis for green chemistry technology assessment.

    Science.gov (United States)

    Kim, Sungjune; Hong, Seokpyo; Ahn, Kilsoo; Gong, Sungyong

    2015-01-01

    This study presents the indicators and proxy variables for the quantitative assessment of green chemistry technologies and evaluates the relative importance of each assessment element by consulting experts from the fields of ecology, chemistry, safety, and public health. The results collected were subjected to an analytic hierarchy process to obtain the weights of the indicators and the proxy variables. These weights may prove useful in avoiding having to resort to qualitative means in absence of weights between indicators when integrating the results of quantitative assessment by indicator. This study points to the limitations of current quantitative assessment techniques for green chemistry technologies and seeks to present the future direction for quantitative assessment of green chemistry technologies.

  18. The Rules of Ferrous Metallurgy

    Science.gov (United States)

    2010-01-01

    The ways in which the sciences have been delineated and categorized throughout history provide insights into the formation, stabilization, and establishment of scientific systems of knowledge. The Dresdener school’s approach for explaining and categorizing the genesis of the engineering disciplines is still valid, but needs to be complemented by further-reaching methodological and theoretical reflections. Pierre Bourdieu’s theory of social practice is applied to the question of how individual agents succeed in influencing decisively a discipline’s changing object orientation, institutionalisation and self-reproduction. Through the accumulation of social, cultural and economic capital, they succeed in realising their own organisational ideas and scientific programs. Key concepts for the analysis include the struggle for power and resources, monopolies of interpretation, and the degree of autonomy. A case study from the Aachener Technische Hochschule shows that the consolidation of ferrous metallurgy can be conceived as a symbolical struggle between Fritz Wüst, professor for ferrous metallurgy, and the German Iron and Steel Institute, leading to a construction of a system of differences in which scientists accepted being scientists rather than entrepreneurs, and entrepreneurs accepted becoming entrepreneurs and renounced science.

  19. Advances in the extractive metallurgy of selected rare and precious metals

    Science.gov (United States)

    Hoffmann, James E.

    1991-04-01

    The broad field of extractive metallurgy, often perceived as an unimportant point of light in the universe of technology, has undergone significant, fundamental changes in the past 30 years. Improved extraction technologies now permit greater metal recovery, reduce the time that metal values are chemically locked up and diminish the economic impact of environmental regulations. Much of this accomplishment is due to the application of solvent extraction. As evidenced by improvements in the extraction of rare and precious metals, research in extractive metallurgy technology not only exists, but has achieved palpable results.

  20. A Unique Master's Program in Combined Nuclear Technology and Nuclear Chemistry at Chalmers University of Technology, Sweden

    Science.gov (United States)

    Skarnemark, Gunnar; Allard, Stefan; Ekberg, Christian; Nordlund, Anders

    2009-08-01

    The need for engineers and scientists who can ensure safe and secure use of nuclear energy is large in Sweden and internationally. Chalmers University of Technology is therefore launching a new 2-year master's program in Nuclear Engineering, with start from the autumn of 2009. The program is open to Swedish and foreign students. The program starts with compulsory courses dealing with the basics of nuclear chemistry and physics, radiation protection, nuclear power and reactors, nuclear fuel supply, nuclear waste management and nuclear safety and security. There are also compulsory courses in nuclear industry applications and sustainable energy futures. The subsequent elective courses can be chosen freely but there is also a possibility to choose informal tracks that concentrate on nuclear chemistry or reactor technology and physics. The nuclear chemistry track comprises courses in e.g. chemistry of lanthanides, actinides and transactinides, solvent extraction, radioecology and radioanalytical chemistry and radiopharmaceuticals. The program is finished with a one semester thesis project. This is probably a unique master program in the sense of its combination of deep courses in both nuclear technology and nuclear chemistry.

  1. Microscale chemistry technology exchange at Argonne National Laboratory - east.

    Energy Technology Data Exchange (ETDEWEB)

    Pausma, R.

    1998-06-04

    The Division of Educational Programs (DEP) at Argonne National Laboratory-East interacts with the education community at all levels to improve science and mathematics education and to provide resources to instructors of science and mathematics. DEP conducts a wide range of educational programs and has established an enormous audience of teachers, both in the Chicago area and nationally. DEP has brought microscale chemistry to the attention of this huge audience. This effort has been supported by the U.S. Department of Energy through the Environmental Management Operations organization within Argonne. Microscale chemistry is a teaching methodology wherein laboratory chemistry training is provided to students while utilizing very small amounts of reagents and correspondingly small apparatus. The techniques enable a school to reduce significantly the cost of reagents, the cost of waste disposal and the dangers associated with the manipulation of chemicals. The cost reductions are achieved while still providing the students with the hands-on laboratory experience that is vital to students who might choose to pursue careers in the sciences. Many universities and colleges have already begun to switch from macroscale to microscale chemistry in their educational laboratories. The introduction of these techniques at the secondary education level will lead to freshman being better prepared for the type of experimentation that they will encounter in college.

  2. Development and Implementation of High School Chemistry Modules Using Touch-Screen Technologies

    Science.gov (United States)

    Lewis, Maurica S.; Zhao, Jinhui; Montclare, Jin Kim

    2012-01-01

    Technology was employed to motivate and captivate students while enriching their in-class education. An outreach program is described that involved college mentors introducing touch-screen technology into a high school chemistry classroom. Three modules were developed, with two of them specifically tailored to encourage comprehension of molecular…

  3. Metallurgy

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@Metallurgical Council of China Council for the Promotion of International Trade(MC-CCPIT)is an organization engaged in promoting foreign trade and economic cooperation for Chinese metallurgical industry.

  4. Annual Review on Yunnan Metallurgy in 2011%2011年云南冶金年评

    Institute of Scientific and Technical Information of China (English)

    谢刚

    2012-01-01

    Based on the papers by metallurgical researchers in Yunnan in 2011, the ferrous metallurgy, nonferrous metallurgy, semimetal and rare metal metallurgy, and noble metal in production, scientific research and technology in Yunnan are summarized.%依据2011年云南冶金科技工作者发表的文献资料,对该年度云南黑色金属冶金、有色金属冶金、半金属及稀有金属冶金和贵金属生产、科研及技术进行了评述.

  5. Advanced chemistry of monolayers at interfaces trends in methodology and technology

    CERN Document Server

    Imae, Toyoko

    2007-01-01

    Advanced Chemistry of Monolayers at Interfaces describes the advanced chemistry of monolayers at interfaces. Focusing on the recent trends of methodology and technology, which are indispensable in monolayer science. They are applied to monolayers of surfactants, amphiphiles, polymers, dendrimers, enzymes, and proteins, which serve many uses.Introduces the methodologies of scanning probe microscopy, surface force instrumentation, surface spectroscopy, surface plasmon optics, reflectometry, and near-field scanning optical microscopy. Modern interface reaction method, lithographic tech

  6. Chemistry of Stable Carbenes and «Green» Technologies

    Directory of Open Access Journals (Sweden)

    Korotkikh, N.I.

    2015-11-01

    Full Text Available Brief analysis of fundamental research in the chemistry of stable carbenes and applications in the field of «green» chemistry on their basis carried out at the L.M. Litvinenko Institute of Physical Organic & Coal Chemistry of NAS of Ukraine over the last decade is given. Carbene versions of ester Claisen condensation to form zwitterionic compounds, the Leuckart-Wallach reaction with the autoreduction of carbenoid azolium salts, Hofmann cleavage of aminocarbene insertion products, an induced tandem autotransformation of 1,2,4-triazol-5-ylidenes into 5-amidino-1,2,4-triazoles were found. New carbene reactions of ad dition, deesterification, oxidation and complexation were revealed. Effective methods of obtaining stable carbenes and carbenoids were suggested. New types of carbenes, namely benzimidazolylidenes, superstable conjugated biscarbenes and new types of carbenoids were synthesized. The existence of hypernucleophilic carbenes was theoretically predicted and experimentally confirmed. The prospects of the use of carbenes and their derivatives, in particular, carbene complexes of transition metals in catalysis of organic reactions and the search of biologically active compounds were shown.

  7. Creation of medicinal chemistry learning communities through enhanced technology and interdisciplinary collaboration.

    Science.gov (United States)

    Henriksen, Brian; Roche, Victoria

    2012-10-12

    Objectives. To build an integrated medicinal chemistry learning community of campus and distance pharmacy students though the use of innovative technology and interdisciplinary teaching.Design. Mechanisms were implemented to bring distance students into campus-based medicinal chemistry classrooms in real time, stimulate interaction between instructors and various student cohorts, and promote group work during class. Also, pharmacy clinician colleagues were recruited to contribute to the teaching of the 3 medicinal chemistry courses.Assessment. Student perceptions on the value of technology to build community and advance learning were gleaned from course evaluations, in class feedback, and conversations with class officers and student groups. Responses on a survey of second-year students confirmed the benefits of interdisciplinary content integration on engagement and awareness of the connection between drug chemistry and pharmacy practice. A survey of clinician colleagues who contributed to teaching the 3 medicinal chemistry courses found their views were similar to those of students.Conclusions. The purposeful use of technology united learners, fostered communication, and advanced content comprehension in 3 medicinal chemistry courses taught to campus and distance students. Teaching collaboration with pharmacy clinicians enhanced learner interest in course content and provided insight into the integrated nature of the profession of pharmacy.

  8. [Respiratory diseases in metallurgy production workers].

    Science.gov (United States)

    Shliapnikov, D M; Vlasova, E M; Ponomareva, T A

    2012-01-01

    The authors identified features of respiratory diseases in workers of various metallurgy workshops. Cause-effect relationships are defined between occupational risk factors and respiratory diseases, with determining the affection level.

  9. Ginger--chemistry, technology, and quality evaluation: part 1.

    Science.gov (United States)

    Govindarajan, V S

    1982-01-01

    Ginger is used in more ways than any other spice. This monograph, published in two parts, comprehensively reviews production, trade, processing, chemistry, and evaluation of quality. Botany, world varieties, agronomy, crop improvement and potential are reviewed briefly with emphasis on the yield of functional components. Processing for the market, international trade patterns, and factors influencing them are discussed. Derived products such as ginger powder, syruped ginger, volatile oil, and oleoresin are discussed in greater detail. The increasing world demand for quality products of added value such as the oleoresin and volatile oil show prospects for their production in the growing countries. The chemistry of the components which contribute aroma and pungency that characterize ginger is critically reviewed. The second part deals with evaluation of quality. The physico-chemical parameters prescribed as a measure of quality for ginger and its products in the existing standards can assure only hygienic quality and purity, and possibly the source, when new parameters such as GC-fingerprints are included. The importance of sensorily evaluating flavor quality is emphasized to understand the variation in flavor quality required by the industrial and retail markets. Related areas, such as problems in sensory evaluation of intense flavored substances, objective flavor profile analysis, and correlation of instrumental and sensory data, are discussed and our recent work in this area is summarized. Areas where more research are needed are indicated. Other areas briefly discussed are functional, physiological, and toxicological properties in use of ginger; biosynthetic aspects of the components stimulating flavor; and structure and pungency and chemistry of spices from allied species and genera. A comprehensive bibliography is provided to aid in further study and research.

  10. Ginger-chemistry, technology, and quality evaluation: part 2.

    Science.gov (United States)

    Govindarajan, V S

    1982-01-01

    Ginger is used in more ways than any other spice. This monograph, published in two parts, comprehensively reviews production, trade, processing, chemistry, and evaluation of quality. Botany, world varieties, agronomy, crop improvement, and potential are reviewed briefly with emphasis on the yield of functional components. Processing for the market, international trade patterns and factors influencing them are discussed. Derived products such as ginger powder, syruped ginger, volatile oil, and oleoresin are discussed in greater detail. The increasing world demand for quality products of added value such as the oleoresin and volatile oil show the prospects for their production in the growing countries. The chemistry of the components which contribute aroma and pungency that characterize ginger is critically reviewed. The second part deals with evaluation of quality. The physicochemical parameters prescribed as a measure of quality for ginger and its products in the existing standards, can assure only hygienic quality and purity, and possibly the source, when new parameters such as GC-finger prints are included. The importance of sensorily evaluating flavor quality is emphasized to understand the variation in flavor quality required by the industrial and retail markets. Related areas, such as problems in sensory evaluation of intense flavored substances, objective flavor profile analysis, correlation of instrumental and sensory data are discussed, and our recent work in this area is summarized. Areas where more research is needed are indicated. Other areas briefly discussed are functional, physiological, and toxicological properties in use of ginger; biosynthetic aspects of components stimulating flavor; structure and pungency and chemistry of spices from allied species and genera. A comprehensive bibliography is provided to aid in further study and research.

  11. Electrothermal Defect Detection in Powder Metallurgy Compacts

    Science.gov (United States)

    Benzerrouk, Souheil; Ludwig, Reinhold; Apelian, Diran

    2006-03-01

    Faced with increasing market pressures, metal part manufacturers have turned to new processes and fabrication technologies. One of these processes is powder metallurgy (P/M), which is employed for low-cost, high-volume precision part manufacturing. Despite many advantages, the P/M process has created a number of challenges, including the need for high-speed quality assessment and control, ideally for each compact. Consequently, sophisticated quality assurance is needed to rapidly detect flaws early in the manufacturing cycle and at minimal cost. In this paper we will discuss our progress made in designing and refining an active infrared (IR) detection system for P/M compacts. After discussing the theoretical background in terms of underlying equations and boundary conditions, analytical and numerical solutions are presented that are capable of predicting temperature responses for various defect sizes and orientations of a dynamic IR testing system. Preliminary measurements with controlled and industrial samples have shown that this active IR methodology can successfully be employed to test both green-state and sintered P/M compacts. The developed system can overcome many limitations observed with a standard IR testing methodology such as emissivity, background calibration, and contact resistance.

  12. A major advance in powder metallurgy

    Science.gov (United States)

    Williams, Brian E.; Stiglich, Jacob J., Jr.; Kaplan, Richard B.; Tuffias, Robert H.

    1991-01-01

    Ultramet has developed a process which promises to significantly increase the mechanical properties of powder metallurgy (PM) parts. Current PM technology uses mixed powders of various constituents prior to compaction. The homogeneity and flaw distribution in PM parts depends on the uniformity of mixing and the maintenance of uniformity during compaction. Conventional PM fabrication processes typically result in non-uniform distribution of the matrix, flaw generation due to particle-particle contact when one of the constituents is a brittle material, and grain growth caused by high temperature, long duration compaction processes. Additionally, a significant amount of matrix material is usually necessary to fill voids and create 100 percent dense parts. In Ultramet's process, each individual particle is coated with the matrix material, and compaction is performed by solid state processing. In this program, Ultramet coated 12-micron tungsten particles with approximately 5 wt percent nickel/iron. After compaction, flexure strengths were measured 50 percent higher than those achieved in conventional liquid phase sintered parts (10 wt percent Ni/Fe). Further results and other material combinations are discussed.

  13. Research on Mineral Processing-metallurgy Combination Technology for an Oxidized Gold Ore in Gansu%甘肃某氧化型金矿石选冶技术研究

    Institute of Scientific and Technical Information of China (English)

    毛益林; 陈晓青; 杨进忠; 王秀芬

    2015-01-01

    甘肃某氧化型金矿石金含量为2.25 g/t,伴生银可综合回收。金主要以独立金矿物形式存在,大部分被载金脉石矿物石英所包裹,少部分以微细粒的形式嵌布在黄铁矿、磁黄铁矿、闪锌矿、黄铜矿和方铅矿等矿物的裂隙中。为高效开发利用该矿石资源,对其进行了选冶联合试验研究。结果表明:在磨矿细度为-0.074 mm占73.00%条件下,经1粗1精2扫浮选、浮选尾矿重选的闭路流程可获得金品位74.2 g/t、回收率91.28%的混合金精矿。混合金精矿经石灰预处理后,经氰化钠浸出,获得了金浸出率为96.52%、金总回收率为88.10%的指标。试验结果对同类型金矿石的选矿回收具有借鉴意义。%The oxidized gold ore in Gansu contains 2. 25 g/t gold and associated silver can be comprehensively recov-ered. Gold mainly exists in form of independent mineral,most gold ore were wrapped in gangue minerals,like quartz,few others was inlayed in the cracks of pyrite,magnetic pyrite,sphalerite,chalcopyrite and galena with the form of fine particles. In order to high efficiently utilize the resource,mineral processing-metallurgy combination experimental research was carried out based on process mineralogy. The results indicate that the mixed concentration with gold grade and recovery of 74. 2 g/t and 91. 28%can be obtained at the grinding fineness of 73. 00% passing 0. 074 mm,via one roughing-one cleaning-two scavenging floatation operation,and gravity separation for floatation tailings. Gold leaching rate of 96. 52% and total recovery of 88. 10% was ob-tained by lime pretreatment with mixed concentrate and then leaching by sodium cyanide. The experimental results can provide technology basis for beneficiation of the ore in same type.

  14. The Beginnings of Metallurgy: A New Look: Arguments over diffusion and independent invention ignore the complex metallurgic crafts leading to iron.

    Science.gov (United States)

    Wertime, T A

    1973-11-30

    In the 9 years since my first survey of early metallurgy appeared in this journal (65) metallurgy has become a major battleground between those who argue independent invention and those who argue diffusion in the evolution of urban civilization. In this new article I contend that: 1) The upland belt and debouching river valleys of southwestern Asia have a clear priority in the beginnings of copper metallurgy and extractive metallurgy generally, suggesting that the forces of urbanization contributing to the rise of metallurgy there were more massive, widespread, and better integrated than elsewhere. 2) The trend to polymetallism, against the background of pyrotechnology generally and the other important technologies of urbanism, established a necessary sequence to early metallurgy. This sequence was a prerequisite to the coming of the Iron Age, which was uniquely contained at first within the environment of Anatolia and the eastern Mediterranean and spread outward from there. 3) The course of metallurgy and possibly of the other urbanizing technologies can best be understood through a process of diffusion and multiple innovation interrelating metallurgical evolution over much of Eurasia, but with the area defined by the Black Sea, the Caspian Sea, the Red Sea, and the eastern Mediterranean as its center. Only in this fashion can we place metallurgy in its proper role as an important subsystem in the rise of civilization.

  15. Self-Paced Tutorial Courses for Mineral Science - Metallurgy Departments. Final Progress Report (July 1975-August 1980).

    Science.gov (United States)

    Twidwell, L. G.

    Four courses in extractive metallurgy (Pyrometallurgy, Hydrometallurgy, Electrometallurgy; and Physical Chemistry of Iron and Steel) were prepared in a modular, self-paced format. Development of the course materials included: (1) preparation of course outlines by unit coordinators and advisory committees; (2) approval of course outlines (included…

  16. Development of electroslag metallurgy and casting in China

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    The electroslag metallurgy has been developed since 1958. At present, all special steel plants have constructed electroslag metallurgical workshops. There are 86 Electroslag Remelting (ESR) furnaces in these steel plants with annual capacity of 100 000 tons. The products by ESR include 243 designations of steel and superalloy. The Chinese metallurgists have made significant achievements in the type and structure of electroslag remelting furnaces, eletroslag remelting technology, shaped castings by Electroslag Remelting Casting (ESRC), the manufacture of large-size ingots by ESR and the study of ESR mechanism. These achievements have already been recognized by foreign metallurgists.

  17. Exploring the Gas Chemistry of Old Submarine Technologies Using Plastic Bottles as Reaction Vessels and Models

    Science.gov (United States)

    Horikoshi, Ryo; Takeiri, Fumitaka; Kobayashi, Yoji; Kageyama, Hiroshi

    2016-01-01

    We describe an activity that is suitable for high school students and makes use of plastic bottles. This activity allows students to familiarize themselves with gas chemistry by introducing technologies that were applied in old submarine systems. Plastic bottles, which are representative of submarines, are used as reaction vessels. Three simple…

  18. Adapting to Student Learning Styles: Engaging Students with Cell Phone Technology in Organic Chemistry Instruction

    Science.gov (United States)

    Pursell, David P.

    2009-01-01

    Students of organic chemistry traditionally make 3 x 5 in. flash cards to assist learning nomenclature, structures, and reactions. Advances in educational technology have enabled flash cards to be viewed on computers, offering an endless array of drilling and feedback for students. The current generation of students is less inclined to use…

  19. Enabling Chemistry Technologies and Parallel Synthesis-Accelerators of Drug Discovery Programmes.

    Science.gov (United States)

    Vasudevan, A; Bogdan, A R; Koolman, H F; Wang, Y; Djuric, S W

    There is a pressing need to improve overall productivity in the pharmaceutical industry. Judicious investments in chemistry technologies can have a significant impact on cycle times, cost of goods and probability of technical success. This perspective describes some of these technologies developed and implemented at AbbVie, and their applications to the synthesis of novel scaffolds and to parallel synthesis. © 2017 Elsevier B.V. All rights reserved.

  20. Quarterly Progress Report Metallurgy Development Operation: October - December 1963

    Energy Technology Data Exchange (ETDEWEB)

    Wick, O. J. [Hanford Site (HNF), Richland, WA (United States). Metallurgy Development Operation; Last, G. A. [Hanford Site (HNF), Richland, WA (United States). Metallurgy Development Operation. Fuels Design; Minor, J. E. [Hanford Site (HNF), Richland, WA (United States). Metallurgy Development Operation. Metal Fabrication Development; Nelson, T. C. [Hanford Site (HNF), Richland, WA (United States). Metallurgy Development Operation. Plutonium Product Development; Stewart, R. W. [Hanford Site (HNF), Richland, WA (United States). Metallurgy Development Operation. Plutonium Metallurgy Development

    1964-01-20

    The present Quarterly Report covers the Metallurgy Development Operation from October to December 1963 and includes research conducted by the Fuels Design, Metal Fabrication Development, Plutonium Product Development, and Plutonium Metallurgy Development Operations. The titles of the chapters are the following: Metallic Fuels Design, Metallic Fuel Development, Refractory Metals and Fuel Development, and Plutonium Physical Metallurgy.

  1. Citrus fruits. Part II. Chemistry, technology, and quality evaluation. B. Technology.

    Science.gov (United States)

    Ranganna, S; Govindarajan, V S; Ramana, K V

    1983-01-01

    In Part II of this review on citrus fruits, the literature on chemistry, technology, and quality evaluation are critically considered. Sweet oranges, mandarin, grapefruit, lemon, and lime are generally used for processing. The literature on chemical components of citrus fruit which include sugars, polysaccharides, organic acids, nitrogenous constituents and lipids; carotenoids which contribute to color; vitamins and minerals and flavonoids; limonoids, some of which impart bitterness to the juice; and the volatile components which contribute to aroma were reviewed in section A. Chilled and pasteurized juices, juice concentrates, and beverages are the important products manufactured commercially, and to a limited extent powdered citrus juices, canned segments, and marmalades. The literature on the manufacture of these products also as new types of juice and oil extractors; TASTE and other types of evaporators; tank farms to store juice and concentrate in bulk; aseptic filling in bulk containers and retail packs; alternate flexible and rigid containers other than glass and tin; and recovery of volatile flavoring constituents during juice processing are some of the important technological developments in the recent past and have been discussed in this section. Bitterness in citrus juices and its control, composition of cloud, and its stability and changes during storage have been reviewed. Essential oils, pectin, frozen and dried juice sacs, dried pulp and molasses, flavonoids, seed oil, and meal are the important byproducts, the manufacture of which is given in essential details. Generally, consumers judge the product on the basis of its sensory attributes. The quality of finished product is dependent upon the raw materials used and control of processes. In section C, the U.S. Department of Agriculture (USDA) standards for different products, physicochemical and microbiological parameters prescribed as indices of quality of fruit, juice, concentrate, and other

  2. Workability Behaviour of Powder Metallurgy Aluminium Composites

    Directory of Open Access Journals (Sweden)

    S. Narayan

    2014-01-01

    Full Text Available An efficient way to find the workability limit for powder metallurgy parts has been suggested. Compacts of Al-4%TiC, Al-4%WC, Al-4%Fe3C, and Al-4%Mo2C were produced to the relative density of 0.82 and 0.86 with three different geometries through primary operations of powder metallurgy routes. Each sintered compact was hot deformed to various strain levels till a visible crack appeared at the free surface. Oyane’s fracture principle was used to develop a theory to study powder metallurgy compacts. A least square technique was used to determine the constants in fracture criteria and these equations were finally used to find workability limit. It is found that the projected technique was well in agreement with the experimental values.

  3. Usage and applications of Semantic Web techniques and technologies to support chemistry research.

    Science.gov (United States)

    Borkum, Mark I; Frey, Jeremy G

    2014-01-01

    The drug discovery process is now highly dependent on the management, curation and integration of large amounts of potentially useful data. Semantics are necessary in order to interpret the information and derive knowledge. Advances in recent years have mitigated concerns that the lack of robust, usable tools has inhibited the adoption of methodologies based on semantics. THIS PAPER PRESENTS THREE EXAMPLES OF HOW SEMANTIC WEB TECHNIQUES AND TECHNOLOGIES CAN BE USED IN ORDER TO SUPPORT CHEMISTRY RESEARCH: a controlled vocabulary for quantities, units and symbols in physical chemistry; a controlled vocabulary for the classification and labelling of chemical substances and mixtures; and, a database of chemical identifiers. This paper also presents a Web-based service that uses the datasets in order to assist with the completion of risk assessment forms, along with a discussion of the legal implications and value-proposition for the use of such a service. We have introduced the Semantic Web concepts, technologies, and methodologies that can be used to support chemistry research, and have demonstrated the application of those techniques in three areas very relevant to modern chemistry research, generating three new datasets that we offer as exemplars of an extensible portfolio of advanced data integration facilities. We have thereby established the importance of Semantic Web techniques and technologies for meeting Wild's fourth "grand challenge".

  4. Technology and Bloom's Taxonomy: Tools to facilitate higher-level learning in chemistry

    Science.gov (United States)

    Morgan, Matthew Earle

    This research project ties together chemistry data acquisition technology, introductory chemistry laboratory experiments. and Bloom's Taxonomy of Educational Objectives into a unified learning model. The goal is to provide faculty and introductory chemistry students with the tools and exercises to experience higher levels of learning, as defined by Bloom's taxonomy. The tools developed as part of this project include data acquisition hardware and software, communications software, and computer simulations that enable higher-level learning situations. A series of five experiments using a discovery-based teaching model are developed as part of the learning model. The experiments bring together the hardware tools, software tools, and learning model to place students in situations that require students to use critical thinking skills and experience higher-level learning. Content-related application problems are also included in the experiments. The experiments are divided into three chemistry units of instruction that build on each other, but can also be used independently. Instructor training is an important part of this project. The successful integration of technology into educational situations cannot be accomplished without the support and understanding of faculty, staff, and teaching assistants. This aspect of the project focuses on shifting teaching and learning paradigms to encourage appropriate technology use and allow technology to become a major aspect of the high-level learning environment. Finally, students were surveyed in an attempt to measure the effectiveness of the learning model. Students were evaluated on chemistry concept retention, as well as their perception of learning. They were also asked how well they enjoyed this form of learning. Along with the tools themselves, this project provides templates that can launch future work in this area. The learning model, data acquisition tools, and experiment writing templates are developed here to provide

  5. Cooperative Electronic Mail: Effective Communication Technology for Introductory Chemistry

    Science.gov (United States)

    Pence, Laura E.

    1999-05-01

    One drawback to using cooperative learning in the classroom is that it takes up class time and reduces the amount of content that can be covered during a semester. Cooperative electronic mail is an excellent alternate method of using cooperative learning that shifts the medium of interaction to the computer and encourages students to learn to communicate effectively through technology. In this project, three types of exercises were assigned, one prior to each exam. These three assignments were (i) an open-ended question, (ii) a traditional cooperative activity done electronically, and (iii) an exercise to allow students to write exam questions for each other. The average participation rate in the exercises was 90% over four semesters, which indicated that the project was an effective incentive to get students to use email regularly. The evaluations of the project were also extremely positive. One surprising result of the assessment was that female students gave even more favorable responses than men, suggesting that this project was an excellent way to encourage women to use computer technology.

  6. Enabling technologies and green processes in cyclodextrin chemistry.

    Science.gov (United States)

    Cravotto, Giancarlo; Caporaso, Marina; Jicsinszky, Laszlo; Martina, Katia

    2016-01-01

    The design of efficient synthetic green strategies for the selective modification of cyclodextrins (CDs) is still a challenging task. Outstanding results have been achieved in recent years by means of so-called enabling technologies, such as microwaves, ultrasound and ball mills, that have become irreplaceable tools in the synthesis of CD derivatives. Several examples of sonochemical selective modification of native α-, β- and γ-CDs have been reported including heterogeneous phase Pd- and Cu-catalysed hydrogenations and couplings. Microwave irradiation has emerged as the technique of choice for the production of highly substituted CD derivatives, CD grafted materials and polymers. Mechanochemical methods have successfully furnished greener, solvent-free syntheses and efficient complexation, while flow microreactors may well improve the repeatability and optimization of critical synthetic protocols.

  7. Enabling technologies and green processes in cyclodextrin chemistry

    Directory of Open Access Journals (Sweden)

    Giancarlo Cravotto

    2016-02-01

    Full Text Available The design of efficient synthetic green strategies for the selective modification of cyclodextrins (CDs is still a challenging task. Outstanding results have been achieved in recent years by means of so-called enabling technologies, such as microwaves, ultrasound and ball mills, that have become irreplaceable tools in the synthesis of CD derivatives. Several examples of sonochemical selective modification of native α-, β- and γ-CDs have been reported including heterogeneous phase Pd- and Cu-catalysed hydrogenations and couplings. Microwave irradiation has emerged as the technique of choice for the production of highly substituted CD derivatives, CD grafted materials and polymers. Mechanochemical methods have successfully furnished greener, solvent-free syntheses and efficient complexation, while flow microreactors may well improve the repeatability and optimization of critical synthetic protocols.

  8. Popularising Chemistry in Secondary Schools--through the development of Scientific and Technological Literacy for All

    Institute of Scientific and Technical Information of China (English)

    Jack Holbrook

    2002-01-01

    While chemistry is popular for children of primary school age, its popularity drops dramatically in secondary schools. A potential solution to address this is to recognise the need for greater relevance - relevance to the curriculum, to the needs of society and, in the eyes of the students.The paper tries to puts forward a rethink of the philosophy for school chemistry education, based on the und erlying belief that chemistry education is an integral part of education. The target is labelled scientific and technological literacy for all (STL). STL rejects the notion that chemistry is taught solely to acquire the abilities to be a scientist and supports the vision of a single curriculum goal, applicable to all students.Besides being a philosophy, STL is also a teaching approach. This approach is to initiate the teaching of chemistry topics, starting from a carefully chosen society perspective and to introduce the conceptual learning on a need - to - know basis.A limitation is the professional development of teachers. Suggestion for overcoming this involve workshop on materials development. A concern is expressed in cases where teachers make use of ready - made teaching materials ( a common practice),without first gaining an understanding and an appreciation of the intended philosophy related to these materials.

  9. Designing Catalysts for Clean Technology, Green Chemistry, and Sustainable Development

    Science.gov (United States)

    Meurig Thomas, John; Raja, Robert

    2005-08-01

    There is a pressing need for cleaner fuels (free or aromatics and of minimal sulfur content) or ones that convert chemical energy directly to electricity, silently and without production of noxious oxides and particulates; chemical, petrochemical and pharmaceutical processes that may be conducted in a one-step, solvent-free manner and that use air as the preferred oxidant; and industrial processes that minimize consumption of energy, production of waste, or the use of corrosive, explosive, volatile, and nonbiodegradable materials. All these needs and other desiderata, such as the in situ production and containment of aggressive and hazardous reagents, and the avoidance of use of ecologically harmful elements, may be achieved by designing the appropriate heterogeneous inorganic catalyst, which ideally should be cheap, readily preparable and fully characterizable, preferably under in situ reaction conditions. A range of nanoporous and nanoparticle catalysts that meet most of the stringent demands of sustainable development and responsible (clean) technology is described. Specific examples that are highlighted include the production of adipic acid (precursor of polyamides and urethanes) without the use of concentrated nitric acid nor the production of greenhouse gases such as nitrous oxide; the production of caprolactam (precursor of nylon) without the use of oleum and hydroxylamine sulfate; and the terminal oxyfunctionalization of linear alkanes in air. The topic of biocatalysis and sustainable development is also briefly discussed for the epoxidation of terpenes and fatty acid methyl esters; for the generation of polymers, polylactides, and polyesters; and for the production of 1,3-propanediol from corn.

  10. Toward high performance in Powder Metallurgy

    Directory of Open Access Journals (Sweden)

    Torralba, José M.

    2014-06-01

    Full Text Available Powder Metallurgy (PM is technology well known for mass production of parts at low cost but usually with worse mechanical properties than same parts obtained by alternative routes. But using this technology, high performance materials can be obtained, depending of the processing route and the type and amount of porosity. In this paper, a brief review of the capabilities of powder technology is made with the objective of attaining the highest level of mechanical and physical properties. For this purpose, different strategies over the processing can be chosen: to act over the density/porosity level and properties of the pores, to act over strengthening mechanisms apart from the density of the material (the alloying system, the microstructure, the grain size,.., to improve the sintering activity by different routes and to use techniques that avoid the grain growth during sintering.La Pulvimetalurgia es una tecnología bien conocida por su faceta de producir piezas de forma masiva a bajo coste, pero habitualmente con una pérdida de propiedades mecánicas si se la compara con tecnologías alternativas para obtener las mismas piezas. Sin embargo, mediante esta tecnología, también se pueden obtener piezas de altas prestaciones, dependiendo de la ruta de procesado y del nivel de porosidad. En este trabajo, se realiza una sucinta revisión de las posibilidades de la tecnología de polvos que permitirían obtener los mayores niveles de prestaciones en cuanto a propiedades mecánicas y físicas. Se pueden elegir distintas estrategias en el procesado: actuar sobre el nivel de densidad/porosidad y las propiedades de los poros, actuar sobre mecanismos de endurecimiento distintos a la densidad (el sistema de aleación, la microestructura, el tamaño de grano,…, mejorar la activación durante la sinterización y utilizar técnicas que inhiban el tamaño de grano durante la sinterización.

  11. Powder-Metallurgy Process And Product

    Science.gov (United States)

    Paris, Henry G.

    1988-01-01

    Rapid-solidification processing yields alloys with improved properties. Study undertaken to extend favorable property combinations of I/M 2XXX alloys through recently developed technique of rapid-solidification processing using powder metallurgy(P/M). Rapid-solidification processing involves impingement of molten metal stream onto rapidly-spinning chill block or through gas medium using gas atomization technique.

  12. INTERNET RESOURCES SEARCH METHODOLOGY FOR DEMONSTRATION OF TECHNOLOGICAL PROCESSES IN CHEMISTRY STUDYING

    Directory of Open Access Journals (Sweden)

    Olga M. Naumenko

    2014-01-01

    Full Text Available The question of methodology of organization of search and application of Resources of the Internet is examined for demonstration of technological processes at the study of chemistry in senior school and higher educational establishments of І-ІІ levels of accreditation. Realization of positions of the new State standard of the base and complete secondary education needs creation of the certain methodical going near organization of search and use in the educational process of Resources of the Internet, that can be used in a course of chemistry for demonstration of their practical using, including technological processes. Considerable attention is devoted to advices for teachers in relation to methodology of the use of Resources of the Internet at preparation and realization of practical and laboratory work, other forms of students’ educational-searching activity.

  13. Delivering drugs to the central nervous system: a medicinal chemistry or a pharmaceutical technology issue?

    Science.gov (United States)

    Ricci, Maurizio; Blasi, Paolo; Giovagnoli, Stefano; Rossi, Carlo

    2006-01-01

    This review aims to summarize the non-invasive approaches employed in delivering drugs to the central nervous system which is severely hindered by the presence of the blood-brain barrier (BBB) that limits molecular permeation. Particular attention will be placed on the several available strategies for delivering drugs into the brain, through circumvention of the BBB, in order to critically address the medicinal chemistry and the pharmaceutical technology contributions.

  14. Using Touch-Screen Technology, Apps, and Blogs to Engage and Sustain High School Students' Interest in Chemistry Topics

    Science.gov (United States)

    Kim, Heejoo; Chacko, Priya; Zhao, Jinhui; Montclare, Jin Kim

    2014-01-01

    As part of an outreach program, we integrated chemistry apps with blogging to enhance the learning experience of students in and outside the classroom. Our outreach program involved college mentors who participated in the development and implementation of chemistry lessons alongside the classroom teacher. Three technology-rich modules that focused…

  15. CO2 conversion by plasma technology: insights from modeling the plasma chemistry and plasma reactor design

    Science.gov (United States)

    Bogaerts, A.; Berthelot, A.; Heijkers, S.; Kolev, St.; Snoeckx, R.; Sun, S.; Trenchev, G.; Van Laer, K.; Wang, W.

    2017-06-01

    In recent years there has been growing interest in the use of plasma technology for CO2 conversion. To improve this application, a good insight into the underlying mechanisms is of great importance. This can be obtained from modeling the detailed plasma chemistry in order to understand the chemical reaction pathways leading to CO2 conversion (either in pure form or mixed with another gas). Moreover, in practice, several plasma reactor types are being investigated for CO2 conversion, so in addition it is essential to be able to model these reactor geometries so that their design can be improved, and the most energy efficient CO2 conversion can be achieved. Modeling the detailed plasma chemistry of CO2 conversion in complex reactors is, however, very time-consuming. This problem can be overcome by using a combination of two different types of model: 0D chemical reaction kinetics models are very suitable for describing the detailed plasma chemistry, while the characteristic features of different reactor geometries can be studied by 2D or 3D fluid models. In the first instance the latter can be developed in argon or helium with a simple chemistry to limit the calculation time; however, the ultimate aim is to implement the more complex CO2 chemistry in these models. In the present paper, examples will be given of both the 0D plasma chemistry models and the 2D and 3D fluid models for the most common plasma reactors used for CO2 conversion in order to emphasize the complementarity of both approaches. Furthermore, based on the modeling insights, the paper discusses the possibilities and limitations of plasma-based CO2 conversion in different types of plasma reactors, as well as what is needed to make further progress in this field.

  16. Using digital technologies to enhance chemistry students' understanding and representational skills

    DEFF Research Database (Denmark)

    Hilton, Annette

    and reported on two laboratory based inquiry tasks using digital technologies. Data were collected using pre- and post-tests, student texts and interviews and classroom video-recording. Content analysis of student texts indicated that students were able to generate new knowledge and use multiple...... representations to make explanations on the molecular level. Student interviews and classroom video-recordings suggested that using digital resources to create multimodal texts promoted knowledge transformation and hence deeper reflection on the meaning of data and representations. The study has implications...... for inquiry learning and using digital technologies to enhance students’ understanding of chemistry on multiple levels....

  17. U.S. EPA honors San Francisco Bay Area firm Hybrid Coating Technologies with Green Chemistry Award

    Science.gov (United States)

    SAN FRANCISCO - Today the U.S. Environmental Protection Agency recognized Hybrid Coating Technologies of Daly City, Calif. with a Presidential Green Chemistry Award for developing a safer, plant-based polyurethane for use on floors, furniture and in

  18. Capsicum--production, technology, chemistry, and quality. Part III. Chemistry of the color, aroma, and pungency stimuli.

    Science.gov (United States)

    Govindarajan, V S

    1986-01-01

    The spice capsicum, the fruits of the genus Capsicum (Family Solanaceae), is a very popular food additive in many parts of the world, valued for the important sensory attributes of color, pungency, and aroma. A large number of varieties are widely cultivated and traded. The characteristic carotenoids of the bright red paprika and cayenne-type chillies, the high character impact aroma stimuli, the methoxy pyrazine of green bell capsicum, the esters of ripe tabasco and the highly potent pungency stimuli, and the capsaicinoids of African and other Asian varieties of chillies, have been of great interest to chemists and biochemists. Research workers in other disciplines such as genetics and breeding, agriculture, and technology have been interested in this spice to develop new varieties with combinations of different optimal levels of the stimuli for the sensory attributes and to maximize production of storable products for specific end uses. Physiologists have been intensely studying the action of the highly potent pungency stimuli and social psychologists the curious aspect of growing acceptance and preference for the initially unacceptable pungency sensation. In the sequential review of all these aspects of the fruit spice Capsicum, the earlier two parts covered history, botany, cultivation and primary processing, and processed products, standards, world production, and trade. In Part III, the chemistry, the compositional variations, synthesis and biosynthesis of the functional components, the carotenoids, the volatiles, and the capsaicinoids are comprehensively reviewed.

  19. Powder metallurgy bearings for advanced rocket engines

    Science.gov (United States)

    Fleck, J. N.; Killman, B. J.; Munson, H.E.

    1985-01-01

    Traditional ingot metallurgy was pushed to the limit for many demanding applications including antifriction bearings. New systems require corrosion resistance, better fatigue resistance, and higher toughness. With conventional processing, increasing the alloying level to achieve corrosion resistance results in a decrease in other properties such as toughness. Advanced powder metallurgy affords a viable solution to this problem. During powder manufacture, the individual particle solidifies very rapidly; as a consequence, the primary carbides are very small and uniformly distributed. When properly consolidated, this uniform structure is preserved while generating a fully dense product. Element tests including rolling contact fatigue, hot hardness, wear, fracture toughness, and corrosion resistance are underway on eleven candidate P/M bearing alloys and results are compared with those for wrought 440C steel, the current SSME bearing material. Several materials which offer the promise of a significant improvement in performance were identified.

  20. Computational thermodynamics in electric current metallurgy

    DEFF Research Database (Denmark)

    Bhowmik, Arghya; Qin, R.S.

    2015-01-01

    A priori derivation for the extra free energy caused by the passing electric current in metal is presented. The analytical expression and its discrete format in support of the numerical calculation of thermodynamics in electric current metallurgy have been developed. This enables the calculation...... of electric current distribution, current induced temperature distribution and free energy sequence of various phase transitions in multiphase materials. The work is particularly suitable for the study of magnetic materials that contain various magnetic phases. The latter has not been considered in literature....... The method has been validated against the analytical solution of current distribution and experimental observation of microstructure evolution. It provides a basis for the design, prediction and implementation of the electric current metallurgy. The applicability of the theory is discussed in the derivations....

  1. Corporate governance in Romanian metallurgy industry

    Directory of Open Access Journals (Sweden)

    M. V. Achim

    2014-01-01

    Full Text Available In this paper we propose to assess the quality of the corporate governance of the metallurgy industry operating in the Romanian capital market. The results are compared with the averages recorded in companies listed on Bucharest Stock Exchange. The study highlights that companies listed on Bucharest Stock Exchange which activate in the metallurgical sector have successfully managed to adapt to the requirements of the globalization of the capital market involving the adoption of the best practices of corporate governance.

  2. The Metallurgy of some indian swords

    OpenAIRE

    Williams, Alan; Edge, David

    2007-01-01

    The metallurgy of Indian swords shows many differences from that of European swords. The distinction between "Damascus Steel" (or wootz) and crucible steel is explained. Ten broken blades from the Armoury of the Nizams of Hyderabad were made available for microscopic examination. Six of these seem to been made from crucible steels, and are of notably high quality. By contrast, a group of six randomly collected from Private Collections in England were also examined. Only one of these was made ...

  3. Metallurgy in the Czech Republic: a spatio-temporal view

    Directory of Open Access Journals (Sweden)

    J. Suchacek

    2017-01-01

    Full Text Available The objective of this paper is to introduce the stochastic input-output model of the impact of metallurgy sector on the Czech economy. Contrary to original input-output model, which is of deterministic nature, we reckon with interval estimates of the development of metallurgy sector. They help us to surpass deterministic impediments when analyzing and forecasting the possible developmental tendencies of metallurgy sector in various economies.

  4. Recent advances in medicinal chemistry and pharmaceutical technology--strategies for drug delivery to the brain.

    Science.gov (United States)

    Denora, Nunzio; Trapani, Adriana; Laquintana, Valentino; Lopedota, Angela; Trapani, Giuseppe

    2009-01-01

    This paper provides a mini-review of some recent approaches for the treatment of brain pathologies examining both medicinal chemistry and pharmaceutical technology contributions. Medicinal chemistry-based strategies are essentially aimed at the chemical modification of low molecular weight drugs in order to increase their lipophilicity or the design of appropriate prodrugs, although this review will focus primarily on the use of prodrugs and not analog development. Recently, interest has been focused on the design and evaluation of prodrugs that are capable of exploiting one or more of the various endogenous transport systems at the level of the blood brain barrier (BBB). The technological strategies are essentially non-invasive methods of drug delivery to malignancies of the central nervous system (CNS) and are based on the use of nanosystems (colloidal carriers) such as liposomes, polymeric nanoparticles, solid lipid nanoparticles, polymeric micelles and dendrimers. The biodistribution of these nanocarriers can be manipulated by modifying their surface physico-chemical properties or by coating them with surfactants and polyethylene-glycols (PEGs). Liposomes, surfactant coated polymeric nanoparticles, and solid lipid nanoparticles are promising systems for delivery of drugs to tumors of the CNS. This mini-review discusses issues concerning the scope and limitations of both the medicinal chemistry and technological approaches. Based on the current findings, it can be concluded that crossing of the BBB and drug delivery to CNS is extremely complex and requires a multidisciplinary approach such as a close collaboration and common efforts among researchers of several scientific areas, particularly medicinal chemists, biologists and pharmaceutical technologists.

  5. Textbook on food chemistry and food technology. Vol. 2. Taschenbuch fuer Lebensmittelchemiker und -technologen. Bd. 2

    Energy Technology Data Exchange (ETDEWEB)

    Osteroth, D. (Karlsruhe Univ. (Germany) Fachhochschule Lippe, Lemgo (Germany)) (ed.)

    1991-01-01

    The textbook presents the basic material and knowledge required in the food industry, relating to food technology and food chemistry, and to the legal aspects of food processing. Apart from information on specific analytical methods, which are discussed in detail, information is given other means and approaches for a comprehensive evaluation of food quality, as e.g. sensory evaluation, statistics, microbiology, dietetics, toxicology. There is one chapter dealing with the available methods of food preservation by physical treatment, as e.g. by food irradiation. (VT) With 159 figs.

  6. Synthetics, mineral oils, and bio-based lubricants chemistry and technology

    CERN Document Server

    Rudnick, Leslie R

    2005-01-01

    As the field of tribology has evolved, the lubrication industry is also progressing at an extraordinary rate. Updating the author's bestselling publication, Synthetic Lubricants and High-Performance Functional Fluids, this book features the contributions of over 60 specialists, ten new chapters, and a new title to reflect the evolving nature of the field: Synthetics, Mineral Oils, and Bio-Based Lubricants: Chemistry and Technology. The book contains chapters on all major lubricant fluids used in a wide range of applications. For each type of lubricant, the authors discuss the historical develo

  7. Nanoinformatics: an emerging area of information technology at the intersection of bioinformatics, computational chemistry and nanobiotechnology.

    Science.gov (United States)

    González-Nilo, Fernando; Pérez-Acle, Tomás; Guínez-Molinos, Sergio; Geraldo, Daniela A; Sandoval, Claudia; Yévenes, Alejandro; Santos, Leonardo S; Laurie, V Felipe; Mendoza, Hegaly; Cachau, Raúl E

    2011-01-01

    After the progress made during the genomics era, bioinformatics was tasked with supporting the flow of information generated by nanobiotechnology efforts. This challenge requires adapting classical bioinformatic and computational chemistry tools to store, standardize, analyze, and visualize nanobiotechnological information. Thus, old and new bioinformatic and computational chemistry tools have been merged into a new sub-discipline: nanoinformatics. This review takes a second look at the development of this new and exciting area as seen from the perspective of the evolution of nanobiotechnology applied to the life sciences. The knowledge obtained at the nano-scale level implies answers to new questions and the development of new concepts in different fields. The rapid convergence of technologies around nanobiotechnologies has spun off collaborative networks and web platforms created for sharing and discussing the knowledge generated in nanobiotechnology. The implementation of new database schemes suitable for storage, processing and integrating physical, chemical, and biological properties of nanoparticles will be a key element in achieving the promises in this convergent field. In this work, we will review some applications of nanobiotechnology to life sciences in generating new requirements for diverse scientific fields, such as bioinformatics and computational chemistry.

  8. Synthetic biology and biomimetic chemistry as converging technologies fostering a new generation of smart biosensors.

    Science.gov (United States)

    Scognamiglio, Viviana; Antonacci, Amina; Lambreva, Maya D; Litescu, Simona C; Rea, Giuseppina

    2015-12-15

    Biosensors are powerful tunable systems able to switch between an ON/OFF status in response to an external stimulus. This extraordinary property could be engineered by adopting synthetic biology or biomimetic chemistry to obtain tailor-made biosensors having the desired requirements of robustness, sensitivity and detection range. Recent advances in both disciplines, in fact, allow to re-design the configuration of the sensing elements - either by modifying toggle switches and gene networks, or by producing synthetic entities mimicking key properties of natural molecules. The present review considered the role of synthetic biology in sustaining biosensor technology, reporting examples from the literature and reflecting on the features that make it a useful tool for designing and constructing engineered biological systems for sensing application. Besides, a section dedicated to bioinspired synthetic molecules as powerful tools to enhance biosensor potential is reported, and treated as an extension of the concept of biomimetic chemistry, where organic synthesis is used to generate artificial molecules that mimic natural molecules. Thus, the design of synthetic molecules, such as aptamers, biomimetics, molecular imprinting polymers, peptide nucleic acids, and ribozymes were encompassed as "products" of biomimetic chemistry. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Progammatic mission transformation - chemistry and metallurgy research replacement (CMRR) project

    Energy Technology Data Exchange (ETDEWEB)

    Gunderson, L Nguyen [Los Alamos National Laboratory; Kornreich, Drew E [Los Alamos National Laboratory; Wong, Amy S [Los Alamos National Laboratory

    2011-01-24

    Nuclear posture and policy objectives are: (1) Preventing nuclear proliferation and nuclear terrorism; (2) Reducing the role of nuclear weapons in US national security strategy; (3) Maintaining strategic deterrence and stability at reduced nuclear force levels; (4) Strengthening regional deterrence and reassuring US allies and partners; and (5) Sustaining a safe, secure, and effective nuclear arsenal.

  10. Recent trends in extractive metallurgy

    OpenAIRE

    2009-01-01

    While pyrometallurgical processes are old technology and were the dominant and logical route used to treat sulfide concentrates they are now challenged by new hydrometallurgical processes. In these new processes there have been attempts in the past few years to avoid using autoclaves in the treatment of concentrates of zinc, copper, and nickel. The situation has been recently reversed and pressure hydrometallurgy is being applied in many operations. An outline of these processes is given and ...

  11. Late Bronze age metallurgy in the Italian Eastern Alps: copper smelting slags and mine exploitation

    OpenAIRE

    2013-01-01

    At the end of the second millennium B.C., the extractive metallurgy of copper in Trentino (Italy) achieved a peak of technological efficiency and mass production, as evidenced by the large number of metallurgical sites and the huge amount of slags resulting from the smelting activities. Though different scholars proposed several smelting process models, so far an agreed interpretation of the whole process is lacking. Over 70 slags from the Luserna, Transacqua and Segonzano sites (all l...

  12. Metallurgy Department. Progress Report for the Period 1 January to 31 December 1984

    DEFF Research Database (Denmark)

    Risø National Laboratory, Roskilde

    The activities of the Metallurgy Department at Risø during 1984 are described. The work is presented in three chapters: General Materials Research, Technology and Materials Development, and Fuel Elements. A survey is given of the Department's participation in international collaboration and of its...... activities within education and training. A list (with abstracts) of publications and lectures by the staff during 1984 is included....

  13. Optimisation of the slag mode in the ladle during the steel processing of secondary metallurgy

    OpenAIRE

    Socha, Ladislav; Bažan, Jiří; Gryc, Karel; Morávka, Jan; Styrnal, Petr; Pilka, Václav; Piegza, Zbygněv

    2013-01-01

    Optimisation of the slag mode in the ladle with the help of briquetted fluxing agents, based on Al2O3 under various technological conditions is the object of this paper. The aim of the industrial experiments was to assess the possibility of achieving the optimum chemical composition of the slag that would improve the kinetic conditions of the refining ladle slag during the treatment in secondary metallurgy units. Industrial experiments were focused on comparing the influences of d...

  14. Copper metallurgy at the crossroads

    Directory of Open Access Journals (Sweden)

    Habashi F.

    2007-01-01

    Full Text Available Copper technology changed from the vertical to the horizontal furnace and from the roast reaction to converting towards the end of the last century. However, the horizontal furnace proved to be an inefficient and polluting reactor. As a result many attempts were made to replace it. In the past 50 years new successful melting processes were introduced on an industrial scale that were more energy efficient and less polluting. In addition, smelting and converting were conducted in a single reactor in which the concentrate was fed and the raw copper was produced. The standing problem in many countries, however, is marketing 3 tonnes of sulfuric acid per tonne of copper produced as well as emitting large amounts of excess SO2 in the atmosphere. Pressure hydrometallurgy offers the possibility of liberating the copper industry from SO2 problem. Heap leaching technology has become a gigantic operation. Combined with solvent extraction and electrowinning it contributes today to about 20% of copper production and is expected to grow. Pressure leaching offers the possibility of liberating the copper industry from SO2 problem. The technology is over hundred years old. It is applied for leaching a variety of ores and concentrates. Hydrothermal oxidation of sulfide concentrates has the enormous advantage of producing elemental sulfur, hence solving the SO2 and sulfuric acid problems found in smelters. Precipitation of metals such as nickel and cobalt under hydrothermal conditions has been used for over 50 years. It has the advantage of a compact plant but the disadvantage of producing ammonium sulfate as a co-product. In case of copper, however, precipitation takes place without the need of neutralizing the acid, which is a great advantage and could be an excellent substitute for electrowinning which is energy intensive and occupies extensive space. Recent advances in the engineering aspects of pressure equipment design open the door widely for increased

  15. Recent trends in extractive metallurgy

    Directory of Open Access Journals (Sweden)

    Habashi F.

    2009-01-01

    Full Text Available While pyrometallurgical processes are old technology and were the dominant and logical route used to treat sulfide concentrates they are now challenged by new hydrometallurgical processes. In these new processes there have been attempts in the past few years to avoid using autoclaves in the treatment of concentrates of zinc, copper, and nickel. The situation has been recently reversed and pressure hydrometallurgy is being applied in many operations. An outline of these processes is given and the future trend is discussed.

  16. Densification of powder metallurgy billets by a roll consolidation technique

    Science.gov (United States)

    Sellman, W. H.; Weinberger, W. R.

    1973-01-01

    Container design is used to convert partially densified powder metallurgy compacts into fully densified slabs in one processing step. Technique improves product yield, lowers costs and yields great flexibility in process scale-up. Technique is applicable to all types of fabricable metallic materials that are produced from powder metallurgy process.

  17. Metallurgy and Heat Treating. Welding Module 7. Instructor's Guide.

    Science.gov (United States)

    Missouri Univ., Columbia. Instructional Materials Lab.

    This guide is intended to assist vocational educators in teaching a three-unit module in metallurgy and heat treating. The module is part of a welding curriculum that has been designed to be totally integrated with Missouri's Vocational Instruction Management System. The basic principles of metallurgy and heat treatment and techniques for…

  18. Metals in Past Societies: A Global Perspective on Indigenous African Metallurgy Shadreck Chirikure

    Energy Technology Data Exchange (ETDEWEB)

    Devanathan, Ram [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-10-01

    This slim book (166 pages) shines a spotlight on pre-industrial African metallurgy, its global connections, and anthropological implications. It integrates seemingly disparate disciplines, such as history, geology, ethnography, archeology, and metallurgy, to illustrate the diversity and innovation in metallurgy across Africa and the role of metals in the rise of socio-economic inequalities and political power. The book has 7 chapters and the focus on metals as enablers of human needs and wants is evident in each chapter. The first chapter presents the context of the work and data sources. The second chapter focuses on the origin and development of mining and metallurgy in pre-industrial Africa. Chapter 3 is dedicated to the interaction of nature and culture in the process of mining. Chapter 4 deals with the transformation of the ore into metal by smelting and the sociocultural aspects of this process. Chapter 5 explores the social and cultural roles acquired by metals as a result of fabrication into objects. Chapter 6 examines the social role of metals, trade in metals, cultural contact, proto-globalization, and technology transfer. Finally, Chapter 7 draws lessons for global anthropology from the African experience. The sources of information are adequately cited and the long list of references at the end of each chapter will be a boon to researchers in this field. The author highlights the cultural aspects and social context of the adoption of metallurgy in Africa while drawing parallels between practices in pre-industrial Africa and those in other parts of the world. The book is peppered with delightful vignettes that offer insights into the process of transforming nature into culturally significant objects. For instance, African miners, like their counterparts in Nepal and Latin America, called upon deities, spirits and ancestors to mediate between nature and humans. Women had distinct roles in this process, but there were variations in these roles and in the

  19. Low-Cobalt Powder-Metallurgy Superalloy

    Science.gov (United States)

    Harf, F. H.

    1986-01-01

    Highly-stressed jet-engine parts made with less cobalt. Udimet 700* (or equivalent) is common nickel-based superalloy used in hot sections of jet engines for many years. This alloy, while normally used in wrought condition, also gas-atomized into prealloyed powder-metallurgy (PM) product. Product can be consolidated by hot isostatically pressing (HIPPM condition) and formed into parts such as turbine disk. Such jet-engine disks "see" both high stresses and temperatures to 1,400 degrees F (760 degrees C).

  20. Biaxially textured articles formed by power metallurgy

    Science.gov (United States)

    Goyal, Amit; Williams, Robert K.; Kroeger, Donald M.

    2003-08-26

    A biaxially textured alloy article having a magnetism less than pure Ni includes a rolled and annealed compacted and sintered powder-metallurgy preform article, the preform article having been formed from a powder mixture selected from the group of mixtures consisting of: at least 60 at % Ni powder and at least one of Cr powder, W powder, V powder, Mo powder, Cu powder, Al powder, Ce powder, YSZ powder, Y powder, Mg powder, and RE powder; the article having a fine and homogeneous grain structure; and having a dominant cube oriented {100} orientation texture; and further having a Curie temperature less than that of pure Ni.

  1. Biaxially textured articles formed by powder metallurgy

    Science.gov (United States)

    Goyal, Amit; Williams, Robert K.; Kroeger, Donald M.

    2003-07-29

    A biaxially textured alloy article having a magnetism less than pure Ni includes a rolled and annealed compacted and sintered powder-metallurgy preform article, the preform article having been formed from a powder mixture selected from the group of mixtures consisting of: at least 60 at % Ni powder and at least one of Cr powder, W powder, V powder, Mo powder, Cu powder, Al powder, Ce powder, YSZ powder, Y powder, Mg powder, and RE powder; the article having a fine and homogeneous grain structure; and having a dominant cube oriented {100} orientation texture; and further having a Curie temperature less than that of pure Ni.

  2. Borax as a lubricant in powder metallurgy

    Directory of Open Access Journals (Sweden)

    Héctor Geovanny Ariza-Suarez

    2014-12-01

    were compacted at 700 MPa in a uniaxial press of 15 tons. DSC-TGA analysis of the mixture with borax was realized. The specimens were sintered in a plasma reactor at 1000 for 30 minutes, with a combined atmosphere of hydrogen and argon. Microhardness and density of the sintered samples was haracterized. XRD analysis was realized to detect possible compounds formation by interaction of borax. This paper shows that borax can be used as a lubricant in powder metallurgy.

  3. A pedagogical shift from direct instruction: Technology-assisted inquiry learning (TAIL) in chemistry

    Science.gov (United States)

    Lou, Rena Zhihong

    The purpose of this study was to develop a student-centered Technology-Assisted Inquiry Learning (TAIL) pedagogical approach and compare it with the traditional, teacher-centered, direct instruction approach in a chemistry classroom. The study investigated how the TAIL approach affected community college chemistry students' (n = 21) learning gains and perceptions during a 1.5-hour intervention when compared with the direct instruction approach. A mixed methodology was used that included both quantitative and qualitative analyses. Results led to the following three key findings for novice learners: (a) TAIL had a statistically significant effect on students' procedural application skills improvement when compared with direct instruction; (b) The magnitude of the between-group difference (Cohen's d = 1.41) indicated that TAIL had a cumulative effect on students' learning gains due to its ability to incorporate multiple components including Inquiry, Guidance, Technology, and Collaboration; (c) When combining measures of students' performance and perceived mental effort, TAIL demonstrated high-instructional efficiency with a significant difference in teaching factual knowledge and procedural applications when compared with direct instruction. In summary, the outcome of this study demonstrated both the effectiveness and efficiency of the TAIL approach as a student-centered pedagogy in teaching a basic scientific topic. This study provided a practical demonstration of the pedagogical shift in teaching science from teacher-centered direct instruction to student-centered learning by using computer software as a pedagogical agent. The results of the study contribute to the literature in the fields of guided inquiry learning pedagogy and technology-assisted science teaching.

  4. Mechanical properties of metals for biomedical applications using powder metallurgy process: A review

    Science.gov (United States)

    Dewidar, Montasser Marasy; Yoon, Ho-Chel; Lim, Jae Kyoo

    2006-06-01

    The uses of biomaterials have been revolutionizing the biomedical field in deployment as implants for humans. During the past five decades, many implant materials made of metals have been put into practical use. Powder metallurgy techniques have been used to produce controlled porous structures, such as porous coatings applied for dental and orthopedic surgical implants, which allow bony tissue ingrowth within the implant surface, thereby improving fixation. This paper examines various important metals using powder metallurgy technology to produce elements of a total hip replacement. These alloys are 316L stainless steel alloy, Co-Cr-Mo alloy, and Ti-6Al-4V alloy. Also, this paper examines current information on the mechanical properties. Mechanical properties are discussed as a function of type of materials and process of fabrication. This article addresses the engineering aspects concerning the advantages and disadvantages of each type of material.

  5. Development and analysis of educational technologies for a blended organic chemistry course

    Science.gov (United States)

    Evans, Michael James

    Blended courses incorporate elements of both face-to-face and online instruction. The extent to which blended courses are conducted online, and the proper role of the online components of blended courses, have been debated and may vary. What can be said in general, however, is that online tools for blended courses are typically culled together from a variety of sources, are often very large scale, and may present distractions for students that decrease their utility as teaching tools. Furthermore, large-scale educational technologies may not be amenable to rigorous, detailed study, limiting evaluation of their effectiveness. Small-scale educational technologies run from the instructor's own server have the potential to mitigate many of these issues. Such tools give the instructor or researcher direct access to all available data, facilitating detailed analysis of student use. Code modification is simple and rapid if errors arise, since code is stored where the instructor can easily access it. Finally, the design of a small-scale tool can target a very specific application. With these ideas in mind, this work describes several projects aimed at exploring the use of small-scale, web-based software in a blended organic chemistry course. A number of activities were developed and evaluated using the Student Assessment of Learning Gains survey, and data from the activities were analyzed using quantitative methods of statistics and social network analysis methods. Findings from this work suggest that small-scale educational technologies provide significant learning benefits for students of organic chemistry---with the important caveat that instructors must offer appropriate levels of technical and pedagogical support for students. Most notably, students reported significant learning gains from activities that included collaborative learning supported by novel online tools. For the particular context of organic chemistry, which has a unique semantic language (Lewis

  6. Reducing cognitive load in the chemistry laboratory by using technology-driven guided inquiry experiments

    Science.gov (United States)

    Hubacz, Frank, Jr.

    The chemistry laboratory is an integral component of the learning experience for students enrolled in college-level general chemistry courses. Science education research has shown that guided inquiry investigations provide students with an optimum learning environment within the laboratory. These investigations reflect the basic tenets of constructivism by engaging students in a learning environment that allows them to experience what they learn and to then construct, in their own minds, a meaningful understanding of the ideas and concepts investigated. However, educational research also indicates that the physical plant of the laboratory environment combined with the procedural requirements of the investigation itself often produces a great demand upon a student's working memory. This demand, which is often superfluous to the chemical concept under investigation, creates a sensory overload or extraneous cognitive load within the working memory and becomes a significant obstacle to student learning. Extraneous cognitive load inhibits necessary schema formation within the learner's working memory thereby impeding the transfer of ideas to the learner's long-term memory. Cognitive Load Theory suggests that instructional material developed to reduce extraneous cognitive load leads to an improved learning environment for the student which better allows for schema formation. This study first compared the cognitive load demand, as measured by mental effort, experienced by 33 participants enrolled in a first-year general chemistry course in which the treatment group, using technology based investigations, and the non-treatment group, using traditional labware, investigated identical chemical concepts on five different exercises. Mental effort was measured via a mental effort survey, a statistical comparison of individual survey results to a procedural step count, and an analysis of fourteen post-treatment interviews. Next, a statistical analysis of achievement was

  7. Evaluation of powder metallurgy superalloy disk materials

    Science.gov (United States)

    Evans, D. J.

    1975-01-01

    A program was conducted to develop nickel-base superalloy disk material using prealloyed powder metallurgy techniques. The program included fabrication of test specimens and subscale turbine disks from four different prealloyed powders (NASA-TRW-VIA, AF2-1DA, Mar-M-432 and MERL 80). Based on evaluation of these specimens and disks, two alloys (AF2-1DA and Mar-M-432) were selected for scale-up evaluation. Using fabricating experience gained in the subscale turbine disk effort, test specimens and full scale turbine disks were formed from the selected alloys. These specimens and disks were then subjected to a rigorous test program to evaluate their physical properties and determine their suitability for use in advanced performance turbine engines. A major objective of the program was to develop processes which would yield alloy properties that would be repeatable in producing jet engine disks from the same powder metallurgy alloys. The feasibility of manufacturing full scale gas turbine engine disks by thermomechanical processing of pre-alloyed metal powders was demonstrated. AF2-1DA was shown to possess tensile and creep-rupture properties in excess of those of Astroloy, one of the highest temperature capability disk alloys now in production. It was determined that metallographic evaluation after post-HIP elevated temperature exposure should be used to verify the effectiveness of consolidation of hot isostatically pressed billets.

  8. Green Chemistry Technology and Product Development. Final Report for Intermediary Biochemicals, Inc.

    Energy Technology Data Exchange (ETDEWEB)

    Zeikus, J. Gregory [Michigan State Univ., East Lansing, MI (United States). Dept. of Microbiology & Molecular Genetics

    2010-08-28

    The DOE funds in this award were applied to developing systems to cost effectively produce intermediate (1 dollar$-$1,000 dollars per kg) and fine ($1,000 per kg) chemicals from renewable feedstocks using environmentally responsible processes via collaboration with academic research laboratories to provide targeted technology and early product development. Specifically, development of a thermostable alkaline phosphatase overexpression system to provide supplies and reagents for improved biological test kits, creation of a microbial strain for the efficient production of aspartate from glucose (replacing oil-derived fumarate in aspartate production), and early development research for an electrochemical bioreactor for the conversion of glucose to mannitol were targeted by this research. Also, establishing this positive academic/industrial collaboration with Michigan State University Laboratories and fostering greater inter-laboratory collaboration would also support the strategy of efficiently transitioning academic green chemistry research into the commercial sector and open an avenue to low cost early product development coupled with scientific training.

  9. JPRS Report, Science & Technology, Japan, Powder Metallurgy Technology

    Science.gov (United States)

    2007-11-02

    satisfactory. lmm Figure 2. Photo of a tape wire cross-section The Jc was measured in liquid helium and liquid nitrogen by making four terminals on the...case, BaCOß precipitates and deposits when C02 exists in the atmosphere. At above 90°C, Ba2Cu(OH)6 was also formed. Since the droplet undergoes...YBa2_xKxCu307_5 was prepared by the following process. Barium carbonate (BaCOß), potassium carbonate (K2CO3), yttrium oxide (Y203) and cupric oxide (CuO

  10. The nature of science and technology for pre-service chemistry teacher: A case of techno-chemistry experiment "From Stannum Metalicum to conductive glass"

    Science.gov (United States)

    Mudzakir, A.; Widhiyanti, T.; Hernani, Arifin, M.; Lestari, A. N.; Jauhariansyah, S.

    2017-08-01

    The study was conducted to address the problems related to low Indonesian students' scientific literacy as revealed in the PISA (Program for International Student Assessment) since 2000-2015. Science teachers (e.g. chemistry teacher) must recognize the nature of science (NOS) to assist their students in preparing an explanation of a phenomenon scientifically correctly. Teachers also need to understand critically about nature of technology (NOT) and it relationship with science as well as society. To integrate those two kinds of knowledge (NOS and NOT), we can conduct a techno-science activity, which integrate the technology to science course in pre-service teacher education program, so that they can improve their knowledge about nature of science and technology (NOST) and pedagogical content knowledge related to NOST. The purpose of this study was to construct an inquiry based laboratory activity worksheet for making conductive glass so that the pre-service teacher could explain how the structure of the semiconductor Fluor doped Tin Oxide (SnO2.F) affect their performance. This study we conducted, described how to design a pre-service chemistry teacher education course that can improve recognizing view of NOST by using a framework called model of educational reconstruction (MER). The scientific activities in the course were guided inquiry based techno-chemistry experiments involving "From Stannum Metallicum to Conductive Glass". Conductive glasses are interesting subject research for several reason. The application of this technology could be found on solar cell, OLED, and display panel. The doped Tin dioxide has been deposited on glass substrate using the spray pyrolysis technique at 400-550°C substrate temperature, 4-5 times, 20 cm gap between glass and sprayer and 450 angle to form a thin film which will act as electrical contact. The resistivity is about 0.5 - 15Ω. The product resulted on this study was rated by several expert to find if the worksheet could

  11. Chemistry in the Time of the Pharaohs

    Science.gov (United States)

    Loyson, Peter

    2011-01-01

    The Egyptians were known in the ancient world as experts in many applied chemistry fields such as metallurgy, wine and beer making, glass making, paper manufacture, paint pigments, dyes, cosmetics, perfumes, and pharmaceuticals. They made significant developments in the extraction of metals from their ores, especially copper and gold. The…

  12. Chemistry in the Time of the Pharaohs

    Science.gov (United States)

    Loyson, Peter

    2011-01-01

    The Egyptians were known in the ancient world as experts in many applied chemistry fields such as metallurgy, wine and beer making, glass making, paper manufacture, paint pigments, dyes, cosmetics, perfumes, and pharmaceuticals. They made significant developments in the extraction of metals from their ores, especially copper and gold. The…

  13. Applying informational entropy to the field of metallurgy

    Directory of Open Access Journals (Sweden)

    C. Oprean

    2016-01-01

    Full Text Available This article aims at analysing whether the field of metallurgy in Romania is informationally efficient or not. This field is important for the real Romanian and world-wide economy, that is why the answer to this dilemma is important, and it will determine the investment behaviour of portfolio managers. The Shannon Entropy is our measure for the informational efficiency of the field of metallurgy. The results obtained indicate that the field of metallurgy in Romania is characterized by a weak informational efficiency. Perhaps the most important effect of this result is the impossibility to make predictions in this field. In this context, a technical or chartist analysis is useless.

  14. Chemistry Teacher Candidates' Acceptance and Opinions about Virtual Reality Technology for Molecular Geometry

    Science.gov (United States)

    Saritas, M. T.

    2015-01-01

    The meaningful knowledge creation about molecular geometry has always been the challenge of chemistry learning. In particular, microscopic world of chemistry science (example, atoms, molecules, structures) used in traditional two dimensional way of chemistry teaching can lead to such problem as students create misconceptions. In recent years,…

  15. Science-Technology-Society (STS) and ChemCom Courses Versus College Chemistry Courses: Is There a Mismatch?

    Science.gov (United States)

    Sanger, Michael J.; Greenbowe, Thomas J.

    1996-06-01

    This opinion paper poses questions for the chemical education community to consider about the nature of college chemistry courses and the expected student prerequisites. It also explores the basis for a potential mismatch that may exist for students enrolled in a traditional college chemistry course who have had Science-Technology-Society (STS) or ChemCom courses as their only prior high school chemistry courses. Even though ChemCom and STS courses are not designed to prepare students for traditional college chemistry courses for science and engineering majors, there has been an increase in the number of ChemCom and STS students enrolling in these courses. As background, the general teaching approach of ChemCom and STS courses is discussed in terms of the behaviorist, cognitive, and constructivist learning theories. This article addresses the advantages and disadvantages of high school chemistry courses based on ChemCom and reviews the chemical education research comparing the effectiveness of ChemCom courses to traditional high school chemistry courses. The authors concluded that more research comparing the effect of these instructional methods on both traditional and alternative assessments is warranted.

  16. The mathematical modeling revolution in extractive metallurgy

    Science.gov (United States)

    Szekely, Julian

    1988-08-01

    A brief review is presented of the current state of extractive metallurgy, and it is shown that it is still a significant part of the national economy. Then a definition is given of mathematical models, and the general philosophy of modeling is discussed, together with the cost of models, hardware, and software options. Several illustrative examples are given, drawn from aluminum electrolysis, flash smelting, tundish operations, and plasma systems. The paper is concluded with the future modeling tasks facing us; these include the more widespread applications of models to represent both existing and new processing operations. It is stressed that models can play a major role in developing a holistic approach to metals and materials processing, where the primary extraction and refining operations are combined with the final processing steps.

  17. Warm compaction powder metallurgy of Cu

    Institute of Scientific and Technical Information of China (English)

    NGAI Tungwai Leo; WANG Shang-lin; LI Yuan-yuan; ZHOU Zho-yao; CHEN Wei-ping

    2005-01-01

    A series of experiments were carried out using different admixed lubricant contents,different compaction pressures and temperatures in order to study the warm compaction of copper powder.Results show that too much admixed lubricant will lead to the squeeze out of the lubricant from the compact during the warm compaction processing of Cu powder.Results also show that blisters can be found in sintered samples that contain lubricant less than 0.15% (mass fraction).Optimal warm compaction parameters for producing high density powder metallurgy copper material are obtained.Compacts with green density of 8.6 g/cm3 and a sintered density of 8.83 g/cm3 can be produced by warm compacting the Cu powder,which contains 0.2% admixed lubricant,and is compacted at 145 ℃ with a pressure of 700 Mpa.

  18. [Features of chronic occupational bronchitis in nonferrous metallurgy workers].

    Science.gov (United States)

    Roslaia, N A; Likhacheva, E I; Vagina, E R; Roslyĭ, O F; Zhovtiak, E P; Iarina, A L; Varzina, N V

    2004-01-01

    The authors summarized results of periodic medical examinations and deep clinical studies of metallurgy workers with bronchial and pulmonary disorders. The article covers clinical and functional characteristics of toxic and dust bronchitis, clinical course and manifestations.

  19. The effects of a technology-driven science application on postsecondary chemistry student achievement and self-efficacy

    Science.gov (United States)

    Byrum, Darrell Scott

    The purpose of this study was to establish if distinction exists in both student achievement and self-efficacy through the application of technology-based instructional approach in the laboratory environment of undergraduate chemistry courses. The achievement of 52 college students in the southeastern region of the United States was measured through one posttest assessment. Following this assessment, students were examined through a self-efficacy scale to determine preexisting thoughts of working in an undergraduate chemistry laboratory environment, as well as peer interaction. Accordingly, three separate college chemistry I courses were used to generate data via a nonequivalent control group design. From the three courses, one class was labeled as the treatment group, while the two remaining classes were collectively labeled as the control group. The treatment group was made up of 22 participants, while the control group was comprised of 30 participants. Students in both the control and treatment groups completed the same laboratory experiments; however, the control group used traditional methods for conducting the laboratory experiments while the treatment group implemented a technology-based approach. To measure achievement, data was gathered through the administration of the Conceptual Problems Gases Test (CPGT). Self-efficacy was measured through the College Chemistry Self-Efficacy Scale (CCSS). Results from both instruments were shown through independent samples t-tests; furthermore, as reflected by p values, the technology-driven application did not have a statistically significant difference on student achievement.

  20. Capsicum production, technology, chemistry, and quality. Part 1: History, botany, cultivation, and primary processing.

    Science.gov (United States)

    Govindarajan, V S

    1985-01-01

    The genus Capsicum (Fam. Solanaceae) was known to ancient cultures and was more recently historically associated with the discovery of the New World. This genus provides many species and varieties used in flavoring foods popular in the cuisines of many parts of the world. From the pungent chilli to the colorful paprika and the bell pepper, with its remarkable aroma, the genus is of great interest for its chemistry, sensory attributes, and physiological action. The Capsicums, among the spices, are second only to black pepper in trade both in volume and value. The production of the different pungency forms, the processed seasonings, and the concentrated oleoresins, through technologically advanced processes and in specified standard grades, are critically reviewed. The pungency of Capsicum fruits, its evaluation, chemical structure relationship, its increasing acceptance and preference by a variety of populations are of great research interest. The wide traditional use in the growing regions and its intense physiological effects have attracted the attention of researchers of many different disciplines. These aspects are reviewed in four sequential parts. Part I deals with history, botany, cultivation, and primary processing.

  1. Application of Radiation Chemistry to Some Selected Technological Issues Related to the Development of Nuclear Energy.

    Science.gov (United States)

    Bobrowski, Krzysztof; Skotnicki, Konrad; Szreder, Tomasz

    2016-10-01

    The most important contributions of radiation chemistry to some selected technological issues related to water-cooled reactors, reprocessing of spent nuclear fuel and high-level radioactive wastes, and fuel evolution during final radioactive waste disposal are highlighted. Chemical reactions occurring at the operating temperatures and pressures of reactors and involving primary transients and stable products from water radiolysis are presented and discussed in terms of the kinetic parameters and radiation chemical yields. The knowledge of these parameters is essential since they serve as input data to the models of water radiolysis in the primary loop of light water reactors and super critical water reactors. Selected features of water radiolysis in heterogeneous systems, such as aqueous nanoparticle suspensions and slurries, ceramic oxides surfaces, nanoporous, and cement-based materials, are discussed. They are of particular concern in the primary cooling loops in nuclear reactors and long-term storage of nuclear waste in geological repositories. This also includes radiation-induced processes related to corrosion of cladding materials and copper-coated iron canisters, dissolution of spent nuclear fuel, and changes of bentonite clays properties. Radiation-induced processes affecting stability of solvents and solvent extraction ligands as well oxidation states of actinide metal ions during recycling of the spent nuclear fuel are also briefly summarized.

  2. Using digital technologies to enhance chemistry students' understanding and representational skills

    DEFF Research Database (Denmark)

    Hilton, Annette

    Abstract Chemistry students need to understand chemistry on molecular, symbolic and macroscopic levels. Students find it difficult to use representations on these three levels to interpret and explain data. One approach is to encourage students to use writing-to-learn strategies in inquiry settings...

  3. NATO Advanced Study Institute on Fundamental and Technological Aspects of Organo-f-Element Chemistry

    CERN Document Server

    Fragalà, Ignazio

    1985-01-01

    The past decade has seen a dramatic acceleration of activity and interest in phenomena surrounding lanthanide and actinide organo­ metallic compounds. Around the world, active research in organo-f­ element synthesis, chemistry, catalysis, crystallography, and quantum chemistry is in progress. This activity has spanned a remarkably wide range of disciplines, from synthetic/mechanistic inorganic and organic chemistry to radiochemistry, catalytic chemistry, spectroscopy (vibra­ tional, optical, magnetic resonance, photoelectron, Mossbauer), X-ray and neutron diffraction structural analysis, as well as to crystal field and molecular orbital theoretical studies at the interface of chemistry and physics. These investigations have been motivated both by fundamental and applied goals. The evidence that f-element organo­ metallic compounds have unique chemical and physical properties which cannot be duplicated by organometallic compounds of d-block elements has suggested many new areas of endeavor and application....

  4. Functional dependency between the logistics security system and the MySAP ERP in metallurgy

    Directory of Open Access Journals (Sweden)

    P. Ranitović

    2013-10-01

    Full Text Available MySAP ERP - Enterprise Resource Planning (system - solution which provides a whole set of functions for the business analytics, finance, human resources management, logistics and corporate services has developed from SAP R/3. It is one of the main products of the SAP AG German multinational company and as such, it is a very important element of the international industrial and technological security system. By defining the functional dependency between the security systems (logistics security systems and the IT (My SAP ERP systems in metallurgy, a concept for designing MY SAP ERP system in metallurgic industry is defined, based on the security aspects.

  5. Tannins in Mineral Processing and Extractive Metallurgy

    Directory of Open Access Journals (Sweden)

    Jordan Rutledge

    2015-08-01

    Full Text Available This study provides an up to date review of tannins, specifically quebracho, in mineral processing and metallurgical processes. Quebracho is a highly useful reagent in many flotation applications, acting as both a depressant and a dispersant. Three different types of quebracho are mentioned in this study; quebracho “S” or Tupasol ATO, quebracho “O” or Tupafin ATO, and quebracho “A” or Silvafloc. It should be noted that literature often refers simply to “quebracho” without distinguishing a specific type. Quebracho is most commonly used in industry as a method to separate fluorite from calcite, which is traditionally quite challenging as both minerals share a common ion—calcium. Other applications for quebracho in flotation with calcite minerals as the main gangue source include barite and scheelite. In sulfide systems, quebracho is a key reagent in differential flotation of copper, lead, zinc circuits. The use of quebracho in the precipitation of germanium from zinc ores and for the recovery of ultrafine gold is also detailed in this work. This analysis explores the wide range of uses and methodology of quebracho in the extractive metallurgy field and expands on previous research by Iskra and Kitchener at Imperial College entitled, “Quebracho in Mineral Processing”.

  6. Titanium aluminides production by powder metallurgy

    Energy Technology Data Exchange (ETDEWEB)

    Henriques, V.A.R. [Centro Tecnico Aeroespacial (CTA), Sao Jose dos Campos, SP (Brazil); Silva, C.R.M. [Universidade de Brasilia (UnB), Brasilia, DF (Brazil); Goncalves, F.F.R. [Instituto Tecnologico de Aeronautica (ITA), Sao Jose dos Campos, SP (Brazil)

    2009-07-01

    Full text: The aim of this work is to analyze the gamma-titanium-aluminideo alloys obtained by powder metallurgy. Theses alloys have high temperature resistance (until 850 deg C) for a long time with utilization in aircraft with high speed and can be applied in automotive engines valves or turbocharger rotors. This paper shows the microstructures results of Ti-48Al-2Cr-2Nb obtained by pressureless sintering and hot uniaxial pressing. The powders were mixed for one hour and compacted using cold isostatic pressing (300 MPa). The specimens were processed by sintering in vacuum between 900-1300 deg C and by hot uniaxial pressing (20 MPa) in argon atmosphere between 900-1200 deg C, for 2h. The alloys were characterized by XRD (X-ray diffraction), SEM (Scanning Electron Microscopy), EDS (Energy Dispersive Spectroscopy) and Vickers microhardness measurements. The results evidence that hot uniaxial pressing route has the tendency to obtain gamma-TiAl and alpha 2-Ti3Al intermetallics ( in a lamellar distribution) than the pressureless sintering route, mainly because of the high niobium diffusion in the titanium matrix. (author)

  7. Copper alloys with improved properties: standard ingot metallurgy vs. powder metallurgy

    Directory of Open Access Journals (Sweden)

    Milan T. Jovanović

    2014-09-01

    Full Text Available Three copper-based alloys: two composites reinforced with Al2O3 particles and processed through powder metallurgy (P/M route, i.e. by internal oxidation (Cu-2.5Al composite and by mechanical alloying (Cu-4.7Al2O3 and Cu-0.4Cr-0.08Zr alloy produced by ingot metallurgy (vacuum melting and casting were the object of this investigation. Light microscope and scanning electron microscope (SEM equipped with electron X-ray spectrometer (EDS were used for microstructural characterization. Microhardness and electrical conductivity were also measured. Compared to composite materials, Cu-0.4Cr-0.08Zr alloy possesses highest electrical conductivity in the range from 20 to 800 ℃, whereas the lowest conductivity shows composite Cu-2.5Al processed by internal oxidation. In spite to somewhat lower electrical conductivity (probably due to inadequate density, Cu-2.5Al composite exhibits thermal stability enabling its application at much higher temperatures than materials processed by mechanical alloying or by vacuum melting and casting.

  8. 78 FR 8202 - Meeting of the Joint ACRS Subcommittees on Thermal Hydraulic Phenomena and Materials, Metallurgy...

    Science.gov (United States)

    2013-02-05

    ... Hydraulic Phenomena and Materials, Metallurgy and Reactor Fuels; Notice of Meeting The Joint ACRS Subcommittees on Thermal Hydraulic Phenomena and Materials, Metallurgy and Reactor Fuels will hold a meeting...

  9. Algenol in Fort Myers, Fla. Among Winners of the 20th Annual Presidential Green Chemistry Challenge Awards/Innovative technologies tackle climate change, water, and chemical issues

    Science.gov (United States)

    ATLANTA - Algenol in Fort Myers, Florida is among the winners to be recognized by the U.S. Environmental Protection Agency (EPA) for landmark green chemistry technologies developed by industrial pioneers and leading scientists that turn climate risk

  10. The Metallurgy of some indian swords

    Directory of Open Access Journals (Sweden)

    Williams, Alan

    2007-12-01

    Full Text Available The metallurgy of Indian swords shows many differences from that of European swords. The distinction between "Damascus Steel" (or wootz and crucible steel is explained. Ten broken blades from the Armoury of the Nizams of Hyderabad were made available for microscopic examination. Six of these seem to been made from crucible steels, and are of notably high quality. By contrast, a group of six randomly collected from Private Collections in England were also examined. Only one of these was made of crucible steel, and three of the others were of very mediocre quality. This perhaps represents the quality of blades available to the average Indian soldier.

    La metalurgia de las espadas indias presenta notables diferencias en comparación con la de las europeas. Se explica la distinción entre el ‘acero de Damasco’ (o wootz y el acero de crisol. Se ha realizado un análisis microscópico de un conjunto de diez hojas rotas de espada depositadas en la Armería de los Nizams de Hyderabad. Seis de ellas parecen haber sido realizadas a partir de acero de crisol, y son de elevada calidad. En contraste, se examinó también un grupo de seis espadas de colecciones privadas en Inglaterra. Sólo una de ellas estaba fabricada con acero de crisol, y tres de las otras eran de calidad muy mediocre. Esto representa quizá la calidad de las hojas de espada al alcance del soldado medio indio.

  11. How Science/Technology/Society relations are approached in the contents of organic functions in high school chemistry

    Directory of Open Access Journals (Sweden)

    Carmem Lúcia Costa Amaral

    2009-03-01

    Full Text Available This paper aimed to verify how the relation between Science/Technology/Society (STS is present in Chemistry textbooks recommended by the Brazilian Ministry of Education. The interest in textbooks is due to the fact that they constitute important resources used by teachers to prepare their classes. Thus, researches in this area are necessary to indicate how the authors could improve the quality of their books. We believe that one way to do this is the introduction of the STS relation, which took place because of the necessity in establishing new ways of teaching, specially the teaching of science. One of the goals of STS education is to create conditions to develop abilities and competences that qualify the students for discussions concerning scientific and technologic questions of everyday life. The analysis of testbooks used the descriptors and indicators developed by Fracalanza and Megid-Neto (2006 as reference. In order to carry out the study, we chose the area of Organic Chemistry, more specifically contents referring to organic functions, with great use in society. In general, the results showed that STS relations are not totally observed in the investigated contents, contributing to the development of Chemistry classes through activities apart from the students social context.

  12. Metallurgy and properties of plasma spray formed materials

    Science.gov (United States)

    Mckechnie, T. N.; Liaw, Y. K.; Zimmerman, F. R.; Poorman, R. M.

    1992-01-01

    Understanding the fundamental metallurgy of vacuum plasma spray formed materials is the key to enhancing and developing full material properties. Investigations have shown that the microstructure of plasma sprayed materials must evolve from a powder splat morphology to a recrystallized grain structure to assure high strength and ductility. A fully, or near fully, dense material that exhibits a powder splat morphology will perform as a brittle material compared to a recrystallized grain structure for the same amount of porosity. Metallurgy and material properties of nickel, iron, and copper base alloys will be presented and correlated to microstructure.

  13. Contribution to the study of copper and copper-arsenic archaeo-metallurgy using light element analysis and experimental fusion; Contribution a l`etude de la paleometallurgie du cuivre et du cuivre-arsenic a partir de l`analyse des elements legers et de fusions experimentales

    Energy Technology Data Exchange (ETDEWEB)

    Papillon, F

    1997-12-31

    The objective of this study is to try a direct reconstruction from ancient artefacts of the elaboration technology used in the dawning copper metallurgy. This word is based on both the light elements analysis and the carry out of the principles of physical metallurgy. However the study of an archaeological artefact necessitates the use of non destructive methods. A main aspect of this work consists in developing the most adequate metallographic technique and the methods for the determination of oxygen and carbon by ion beam analysis. Additionally experimental melting of copper and copper arsenic alloys were carried out in laboratory, under various temperature and atmosphere conditions, and `on the field` in Archeodrome de Beaune, in order to reconstruct part of the prehistorical craftsmanship. The results of measurement are consistent with our general knowledge of oxido-reduction phenomena and the behaviour of copper and copper arsenic alloys s in agreement with the prediction of thermodynamics. The nuclear analysis of three ancient artefacts showed that the oxygen and carbon contents were closer to those of the Archeodrome than those of the laboratory. Further studies of the field should consider all parameters controlling the physical-chemistry of charcoal fire. (author) 96 refs.

  14. Perceptions of the effects of clicker technology on student learning and engagement: a study of freshmen Chemistry students

    Directory of Open Access Journals (Sweden)

    Jenepher Lennox Terrion

    2012-03-01

    Full Text Available While technology – in the form of laptops and cellphones – may be the cause of much of the distraction in university and college classrooms, some, including the personal or classroom response system (PRS/CRS or clicker, also present pedagogical opportunities to enhance student engagement. The current study explored the reactions of students to clicker implementation in a large, introductory chemistry class. During the final class of the semester, 200 students in an introductory chemistry class responded to an attitudinal and informational student survey using both Likert-type and non-Likert type questions to evaluate their perception of the implementation of the clickers and their impact on student learning and engagement. The results demonstrated that, when implemented effectively, clickers contribute to greater student engagement and, ultimately, an opportunity for professors to enact best practices in higher education pedagogy. This study points to the importance of effective pedagogy in making clickers worthwhile.

  15. Factors related to the economic sustainability of two-year chemistry-based technology training programs

    Science.gov (United States)

    Backus, Bridgid A.

    Two-year chemistry-based technology training (CBTT) programs in the U.S. are important in the preparation of the professional technical workforce. The purpose of this study was to identify, examine, and analyze factors related to the economic sustainability of CBTT programs. A review of literature identified four clustered categories of 31 sub-factors related to program sustainability. Three research questions relating to program sustainability were: (1) What is the relative importance of the identified factors?, (2) What differences exist between the opinions of administrators and faculty?, and (3) What are the interrelationships among the factors? In order to answer these questions, survey data gathered from CBTT programs throughout the United States were analyzed statistically. Conclusions included the following: (1) Rank order of the importance to sustainability of the clustered categories was: (1) Partnerships, (2) Employer and Student Educational Goals, (3) Faculty and Their Resources, and (4) Community Perceptions and Marketing Strategies. (2) Significant correlations between ratings of sustainability and the sub-factors included: degree of partnering, college responsiveness, administration involvement in partnerships, experiential learning opportunities, employer input in curriculum development, use of skill standards, number of program graduates, student job placement, professional development opportunities, administrator support, presence of a champion, flexible scheduling, program visibility, perception of chemical technicians, marketing plans, and promotion to secondary students. (3) Faculty and administrators differed significantly on only two sub-factor ratings: employer assisted curriculum development, and faculty workloads. (4) Significant differences in ratings by small program faculty and administrators and large program faculty and administrators were indicated, with most between small program faculty and large program administrators. The study

  16. Under bump metallurgy study for Pb-free bumping

    Science.gov (United States)

    Jang, Se-Young; Wolf, Juergen; Paik, Kyung-Wook

    2002-05-01

    The demand for Pb-free and high-density interconnection technology is rapidly growing. The electroplating-bumping method is a good approach to meet finepitch requirements, especially for high-volume production, because to volume change of patterned-solder bumps during reflow is not so large compared with the stencil-printing method. This paper proposes a Sn/3.5 Ag Pb-free electroplating-bumping process for high-density Pb-free interconnects. It was found that a plated Sn/Ag bump becomes Sn/Ag/Cu by reflowing when Cu containing under bump metallurgy (UBM) is used. Another important issue for future flip-chip interconnects is to optimize the UBM system for high-density and Pb-free solder bumps. In this work, four UBM systems, sputtered TiW 0.2 µm/Cu 0.3 µm/electroplated Cu 5 µm, sputtered Cr 0.15 µm/Cr-Cu 0.3 µm/Cu 0.8 µm, sputtered NiV 0.2 µm/Cu 0.8 µm, and sputtered TiW 0.2 µm/NiV 0.8 µm, were investigated for interfacial reaction with electroplated Pb/63Sn and Sn/3.5Ag solder bumps. Both Cu-Sn and Ni-Sn intermetallic compound (IMC) growth were observed to spall-off from the UBM/solder interface when the solder-wettable layer is consumed during a liquid-state “reflow” process. This IMC-spalling mechanism differed depending on the barrier layer material.

  17. Chemistry for engineering students: A key factor for social and technological development

    Directory of Open Access Journals (Sweden)

    Juan Antonio Llorens Molina

    2014-12-01

    Full Text Available The peculiarity of Chemistry as a basic subject in Engineering Studies and its embedded potential difficulties are matters which are now common to universities worldwide. In particular, the learning of Chemistry in the new (post Bologna degrees of Engineering in Spain and other countries is facing several challenges. In other words, there is a need to deepen into research and innovation tasks aiming at improving such studies within this new educational paradigm. Not to mention, two crucial aspects which are very often neglected, namely, reaching maximum efficiency of all types of available resources and obtaining a “knock on effect” from students and teachers at Secondary school level. The latter playing a crucial role so as to increase students’ awareness of the importance that Chemistry has at this particular educational level. Not to mention, how this increases their motivation towards this subject in the Higher Education scenario.

  18. Application of Microwave Technology in Chemistry%微波技术在化学领域的应用

    Institute of Scientific and Technical Information of China (English)

    周维磊; 白锁柱; 王锐

    2015-01-01

    微波是一项能促进化学反应的新技术,对化学过程有非常独特的影响。本文主要从三个方面概括了微波辐射技术在化学领域中的应用,并阐述了微波加热的机理。利用微波技术不仅具有条件温和、能耗低和加热速度快,而且还具有热能利用率高以及产品质量高等优点,因此将技术应用在化工、环境和生物等领域具有更为广阔的应用前景。%Microwave speeding up chemistry reaction is a new technology that microwave energy may have a unique ability to influence chemical processes. the application of microwave in chemistry from there aspects was summaried and its reaction mechanism of microwave heating was explored. There were not only mild conditions, low energy consumption and heating speed for using microwave technology, but also advantages of high heat energy utilization rate and high product quality, so the technology can be applied to chemical industry, environment and biology, and other fields with a wider application prospect.

  19. High Throughput and High Speed Organic Synthesis in Drug Discovery:An Integration of Chemistry and Technology

    Institute of Scientific and Technical Information of China (English)

    Li Chen

    2004-01-01

    Drug discovery is a complicated process that involves multiple synthetic chemistry tasks.Among them, lead generation and optimization is the core business in the discovery research.During the stage of lead generation, a large library of many thousands individual compounds will be screened against a biological target to identify a set of hits that showed desirable activity. Once a hit has been identified, analog synthesis and development of SAR around this hit and establishment of relationship between targeted protein and its cellular function become the key activity in the drug discovery project. During this process, focused libraries of a few hundred compounds (X00) will be synthesized and tested. For synthetic chemistry tasks, the efficiency can be enhanced through "parallel processing or high throughput chemisay" using automation technology with which a large number of compounds can be synthesized, purified and plated at same time for biological and pharmaceutical screenings. To accelerate the lead optimization high speed synthesis is conducted when necessary and to improve "single process" efficiency using automation technology, when the rate limiting step become developing synthetic method to produce large amount of compounds (in gram quantity) that can be used in vivo pharmacology study. With these in mind, we designed integrated HTC technology platform which supports the key chemical synthesis activities in discovery research. In this presentation, several examples will be presented to illustrate the applications of high throughput and high speed organic synthesis in drug discovery.

  20. Research on Low-Grade and High Combination Ratio Copper Oxide Ore from Yunnan by United Technology of Beneficiation and Metallurgy%云南某低品位高结合率氧化铜矿选冶联合试验研究

    Institute of Scientific and Technical Information of China (English)

    崔毅琦; 王飞旺; 孟奇; 童雄; 王凯; 杨波

    2015-01-01

    云南某难选铜矿石属低品位高结合率氧化铜矿,采用选冶联合工艺实现了对该铜矿的高效回收.浮选试验研究表明,磨矿细度为-0.074 mm 占80%,调整剂水玻璃用量800 g/t,组合捕收剂丁黄药+异戊黄(1∶1)用量240 g/t,铜回收指标最佳,经二粗二精闭路试验获得的铜精矿中铜品位9.17%,回收率17.76%.浮选尾矿经磁选除铁,磁选尾矿采用硫酸浸出,当磨矿细度为-0.045 mm 占54%,硫酸用量60 kg/t,液固比3∶1,转速250 r/min,浸出温度45℃,浸出时间2 h 时,铜浸出率为81.88%,铜的综合回收率达86.55%.%A refractory low-grade oxide copper ore from Yunnan which contains large amounts of combined cop-per is studied.Efficient recovery of copper is obtained by united technology of beneficiation and metallurgy.Flo-tation experiments show that with the grinding fineness of -0.074 mm 80%,the sodium silicate dosage 800 g/t,the combination collector of butyl xanthate and isoamyl xanthate (1 ∶1 )dosage 240 g/t,the optimal copper re-covery and grade of the concentrate are 1 7.76% and 9.1 7%,respectively.Iron in flotation tailings is removed by magnetic separation,and the tailings are leaching with sulfuric acid.The copper leaching rate of 81 .88% is obtained with the grinding fineness of -0.045 mm 54%,the sulfuric acid dosage 60 kg/t,the liquid -solid ra-tio 3∶1 ,the speed 250 r/min,the temperature 45℃,the leaching time 2 h,and the total recovery of copper is 86.55%.

  1. [Hygienic evaluation of risk factors on powder metallurgy production].

    Science.gov (United States)

    2011-01-01

    Complex hygienic, clinical, sociologic and epidemiologic studies revealed reliable relationship between work conditions and arterial hypertension, locomotory system disorders, monocytosis in powder metallurgy production workers. Findings are more probable cardiovascular and respiratory diseases, digestive tract diseases due to influence of lifestyle factors.

  2. One step HIP canning of powder metallurgy composites

    Science.gov (United States)

    Juhas, John J. (Inventor)

    1990-01-01

    A single step is relied on in the canning process for hot isostatic pressing (HIP) powder metallurgy composites. The binders are totally removed while the HIP can of compatible refractory metal is sealed at high vacuum and temperature. This eliminates outgassing during hot isostatic pressing.

  3. Nuclear chemistry and geochemistry research. Carnegie Institute of Technology and Carnegie--Mellon University. Summary report

    Energy Technology Data Exchange (ETDEWEB)

    Kohman, T.P.

    1976-05-28

    A summary is presented of the activities and results of research in nuclear chemistry, nuclear geochemistry, nuclear cosmochemistry, and other minor areas from 1950 to 1976. A complete listing is given of publications, doctoral dissertations, and reports resulting from the research. A chronological list provides an overview of the activities at any particular time. (JSR)

  4. Exploring 3-D Virtual Reality Technology for Spatial Ability and Chemistry Achievement

    Science.gov (United States)

    Merchant, Z.; Goetz, E. T.; Keeney-Kennicutt, W.; Cifuentes, L.; Kwok, O.; Davis, T. J.

    2013-01-01

    We investigated the potential of Second Life® (SL), a three-dimensional (3-D) virtual world, to enhance undergraduate students' learning of a vital chemistry concept. A quasi-experimental pre-posttest control group design was used to conduct the study. A total of 387 participants completed three assignment activities either in SL or using…

  5. Exploring 3-D Virtual Reality Technology for Spatial Ability and Chemistry Achievement

    Science.gov (United States)

    Merchant, Z.; Goetz, E. T.; Keeney-Kennicutt, W.; Cifuentes, L.; Kwok, O.; Davis, T. J.

    2013-01-01

    We investigated the potential of Second Life® (SL), a three-dimensional (3-D) virtual world, to enhance undergraduate students' learning of a vital chemistry concept. A quasi-experimental pre-posttest control group design was used to conduct the study. A total of 387 participants completed three assignment activities either in SL or using…

  6. Flow through reactors for organic chemistry: directly electrically heated tubular mini reactors as an enabling technology for organic synthesis

    Directory of Open Access Journals (Sweden)

    Ulrich Kunz

    2009-11-01

    Full Text Available Until recently traditional heating in organic chemistry has been done with oil heating baths or using electric heat exchangers. With the advent of microwave equipment, heating by microwaves was rapidly introduced as standard method in organic chemistry laboratories, mainly because of the convenient possibility to operate at high temperature accompanied by accelerated reaction rates. In the present contribution we discuss the method of heating small, continuously operated reactors by passing electric current directly through the reactor wall as an enabling technology in organic chemistry. The benefit of this method is that the heat is generated directly inside the reactor wall. By this means high heating rates comparable to microwave ovens can be reached but at much lower cost for the equipment. A tool for the comparison of microwave heating and traditional heating is provided. As an example kinetic data for the acid catalyzed hydrolysis of methyl formate were measured using this heating concept. The reaction is not only a suitable model but also one of industrial importance since this is the main production process for formic acid.

  7. Flow through reactors for organic chemistry: directly electrically heated tubular mini reactors as an enabling technology for organic synthesis.

    Science.gov (United States)

    Kunz, Ulrich; Turek, Thomas

    2009-11-30

    Until recently traditional heating in organic chemistry has been done with oil heating baths or using electric heat exchangers. With the advent of microwave equipment, heating by microwaves was rapidly introduced as standard method in organic chemistry laboratories, mainly because of the convenient possibility to operate at high temperature accompanied by accelerated reaction rates. In the present contribution we discuss the method of heating small, continuously operated reactors by passing electric current directly through the reactor wall as an enabling technology in organic chemistry. The benefit of this method is that the heat is generated directly inside the reactor wall. By this means high heating rates comparable to microwave ovens can be reached but at much lower cost for the equipment. A tool for the comparison of microwave heating and traditional heating is provided. As an example kinetic data for the acid catalyzed hydrolysis of methyl formate were measured using this heating concept. The reaction is not only a suitable model but also one of industrial importance since this is the main production process for formic acid.

  8. Flow through reactors for organic chemistry: directly electrically heated tubular mini reactors as an enabling technology for organic synthesis

    Science.gov (United States)

    Turek, Thomas

    2009-01-01

    Summary Until recently traditional heating in organic chemistry has been done with oil heating baths or using electric heat exchangers. With the advent of microwave equipment, heating by microwaves was rapidly introduced as standard method in organic chemistry laboratories, mainly because of the convenient possibility to operate at high temperature accompanied by accelerated reaction rates. In the present contribution we discuss the method of heating small, continuously operated reactors by passing electric current directly through the reactor wall as an enabling technology in organic chemistry. The benefit of this method is that the heat is generated directly inside the reactor wall. By this means high heating rates comparable to microwave ovens can be reached but at much lower cost for the equipment. A tool for the comparison of microwave heating and traditional heating is provided. As an example kinetic data for the acid catalyzed hydrolysis of methyl formate were measured using this heating concept. The reaction is not only a suitable model but also one of industrial importance since this is the main production process for formic acid. PMID:20300506

  9. Environmental legacy of copper metallurgy and Mongol silver smelting recorded in Yunnan Lake sediments.

    Science.gov (United States)

    Hillman, Aubrey L; Abbott, Mark B; Yu, JunQing; Bain, Daniel J; Chiou-Peng, TzeHuey

    2015-03-17

    Geochemical measurements on well-dated sediment cores from Lake Er (Erhai) are used to determine the timing of changes in metal concentrations over 4500 years in Yunnan, a borderland region in southwestern China noted for rich mineral deposits but with inadequately documented metallurgical history. Our findings add new insight into the impacts and environmental legacy of human exploitation of metal resources in Yunnan history. We observe an increase in copper at 1500 BC resulting from atmospheric emissions associated with metallurgy. These data clarify the chronological issues related to links between the onset of Yunnan metallurgy and the advent of bronze technology in adjacent Southeast Asia, subjects that have been debated for nearly half a century. We also observe an increase from 1100 to 1300 AD in a number of heavy metals including lead, silver, zinc, and cadmium from atmospheric emissions associated with silver smelting. Culminating during the rule of the Mongols, known as the Yuan Dynasty (1271-1368 AD), these metal concentrations approach levels three to four times higher than those from industrialized mining activity occurring within the catchment today. Notably, the concentrations of lead approach levels at which harmful effects may be observed in aquatic organisms. The persistence of this lead pollution over time created an environmental legacy that likely contributes to known issues in modern day sediment quality. We demonstrate that historic metallurgical production in Yunnan can cause substantial impacts on the sediment quality of lake systems, similar to other paleolimnological findings around the globe.

  10. ATTENDANCE AND DESERTION IN GENERAL CHEMISTRY AT THE ENGINEERING COURSES OF THE NATIONAL TECHNOLOGICAL UNIVERSITY - CORDOBA REGIONAL FACULTY (UTN-FRC), ARGENTINA

    OpenAIRE

    María C. Oliver; Eimer,Griselda A.; Nancy F. Bálsamo; Mónica E. Crivello

    2011-01-01

    In this paper, it is analyzed the engineering students of the National Technological University - Cordoba Regional Faculty -academic achievement in the learning of Chemistry, as well as desertion , during academic year 2009. The requirement of an intensive and effective leveling course on Chemistry area with teaching tools that facilitate teaching and learning strategies is stated. Moreover, it is suggested to generate instances of coordination to improve the transition from high school to u...

  11. Gold-catalyzed formation of heterocycles - an enabling new technology for medicinal chemistry.

    Science.gov (United States)

    Shen, Hong C; Graham, Thomas H

    2013-01-01

    Gold-catalyzed transformations allow efficient access to a wide scope of heterocyclic structures that serve as building blocks and pharmacophores in medicinal chemistry. Compared with other transition metal and Lewis acid catalysis, gold catalysis presents mechanistic divergence, excellent functional group tolerance and/or operational advantages. Emergent applications of gold catalysis have played a key role in the synthesis of biologically active molecules including a drug candidate.

  12. Nuclear Technology Series. Course 15: Metallurgy and Metals Properties.

    Science.gov (United States)

    Technical Education Research Center, Waco, TX.

    This technical specialty course is one of thirty-five courses designed for use by two-year postsecondary institutions in five nuclear technician curriculum areas: (1) radiation protection technician, (2) nuclear instrumentation and control technician, (3) nuclear materials processing technician, (4) nuclear quality-assurance/quality-control…

  13. Polymer Chemistry

    Science.gov (United States)

    Williams, Martha; Roberson, Luke; Caraccio, Anne

    2010-01-01

    This viewgraph presentation describes new technologies in polymer and material chemistry that benefits NASA programs and missions. The topics include: 1) What are Polymers?; 2) History of Polymer Chemistry; 3) Composites/Materials Development at KSC; 4) Why Wiring; 5) Next Generation Wiring Materials; 6) Wire System Materials and Integration; 7) Self-Healing Wire Repair; 8) Smart Wiring Summary; 9) Fire and Polymers; 10) Aerogel Technology; 11) Aerogel Composites; 12) Aerogels for Oil Remediation; 13) KSC's Solution; 14) Chemochromic Hydrogen Sensors; 15) STS-130 and 131 Operations; 16) HyperPigment; 17) Antimicrobial Materials; 18) Conductive Inks Formulations for Multiple Applications; and 19) Testing and Processing Equipment.

  14. The beginning of metallurgy in the southern Levant: a late 6th millennium CalBC copper awl from Tel Tsaf, Israel.

    Science.gov (United States)

    Garfinkel, Yosef; Klimscha, Florian; Shalev, Sariel; Rosenberg, Danny

    2014-01-01

    The beginning of metallurgy in the ancient Near East attracts much attention. The southern Levant, with the rich assemblage of copper artifacts from the Nahal Mishmar cave and the unique gold rings of the Nahal Qanah cave, is regarded as a main center of early metallurgy during the second half of the 5th millennium CalBC. However, a recently discovered copper awl from a Middle Chalcolithic burial at Tel Tsaf, Jordan Valley, Israel, suggests that cast metal technology was introduced to the region as early as the late 6th millennium CalBC. This paper examines the chemical composition of this item and reviews its context. The results indicate that it was exported from a distant source, probably in the Caucasus, and that the location where it was found is indicative of the social status of the buried individual. This rare finding indicates that metallurgy was first diffused [corrected] to the southern Levant through exchange networks and only centuries later involved local productionThis copper awl, the earliest metal artifact found in the southern Levant, indicates that the elaborate Late Chalcolithic metallurgy developed from a more ancient tradition.

  15. Radiation Chemistry

    Science.gov (United States)

    Wojnárovits, L.

    Ionizing radiation causes chemical changes in the molecules of the interacting medium. The initial molecules change to new molecules, resulting in changes of the physical, chemical, and eventually biological properties of the material. For instance, water decomposes to its elements H2 and O2. In polymers, degradation and crosslinking take place. In biopolymers, e.g., DNS strand breaks and other alterations occur. Such changes are to be avoided in some cases (radiation protection), however, in other cases they are used for technological purposes (radiation processing). This chapter introduces radiation chemistry by discussing the sources of ionizing radiation (radionuclide sources, machine sources), absorption of radiation energy, techniques used in radiation chemistry research, and methods of absorbed energy (absorbed dose) measurements. Radiation chemistry of different classes of inorganic (water and aqueous solutions, inorganic solids, ionic liquids (ILs)) and organic substances (hydrocarbons, halogenated compounds, polymers, and biomolecules) is discussed in concise form together with theoretical and experimental backgrounds. An essential part of the chapter is the introduction of radiation processing technologies in the fields of polymer chemistry, food processing, and sterilization. The application of radiation chemistry to nuclear technology and to protection of environment (flue gas treatment, wastewater treatment) is also discussed.

  16. Combustion and explosion processes in physical chemistry and technology of inorganic materials

    Energy Technology Data Exchange (ETDEWEB)

    Merzhanov, Alexander G [Institute of Structural Macrokinetics and Materials Science, Russian Academy of Sciences, Chernogolovka, Moscow Region (Russian Federation)

    2003-04-30

    This review is the first attempt to generalise, in a descriptive-conceptual form, material-synthesising and material-affecting combustion and explosion processes and relevant physicochemical, technological and materials science problems with special emphasis on their practical (technological and industrial) applications.

  17. The influence of metallurgy on the formation of welding aerosols.

    Science.gov (United States)

    Zimmer, Anthony T

    2002-10-01

    Recent research has indicated that insoluble ultrafine aerosols (ie., particles whose physical diameters are less than 100 nm) may cause adverse health effects due to their small size, and that toxicological response may be more appropriately represented by particle number or particle surface area. Unfortunately, current exposure criteria and the associated air-sampling techniques are primarily mass-based. Welding processes are high-temperature operations that generate substantial number concentrations of ultrafine aerosols. Welding aerosols are formed primarily through the nucleation of metal vapors followed by competing growth mechanisms such as coagulation and condensation. Experimental results and mathematical tools are presented to illustrate how welding metallurgy influences the chemical aspects and dynamic processes that initiate and evolve the resultant aerosol. This research suggests that a fundamental understanding of metallurgy and aerosol physics can be exploited to suppress the formation of undesirable chemical species as well as the amount of aerosol generated during a welding process.

  18. Properties of duplex stainless steels made by powder metallurgy

    OpenAIRE

    Rosso, M.; M. Actis Grande; Z. Brytan; L.A. Dobrzański

    2007-01-01

    Purpose: of this paper was to examine the mechanical properties of duplex stainless steels.Design/methodology/approach: In presented study duplex stainless steels were obtained through powder metallurgy starting from austenitic, martensitic base powders by controlled addition of alloying elements, such as Cr, Ni, Mo and Cu. In the studies behind the preparation of mixes, Schaeffler’s diagram was taken into consideration. Prepared mixes have been sintered in a vacuu...

  19. Powder-metallurgy superalloy strengthened by a secondary gamma phase.

    Science.gov (United States)

    Kotval, P. S.

    1971-01-01

    Description of experiments in which prealloyed powders of superalloy compositions were consolidated by extrusion after the strengthening by precipitation of a body-centered tetragonal gamma secondary Ni3 Ta phase. Thin foil electron microscopy showed that the mechanical properties of the resultant powder-metallurgy product were correlated with its microstructure. The product exhibited high strength at 1200 F without loss of ductility, after thermomechanical treatment and aging.

  20. Alloy element redistribution during sintering of powder metallurgy steels

    OpenAIRE

    Tahir, Abdul Malik

    2014-01-01

    Homogenization of alloying elements is desired during sintering of powder metallurgy components. The redistribution processes such as penetration of liquid phase into the interparticle/grain boundaries of solid particles and subsequent solid-state  diffusion of alloy element(s) in the base powder, are important for the effective homogenization of alloy element(s) during liquid phase sintering of the mixed powders. The aim of this study is to increase the understanding of alloy element redistr...

  1. Microstructure and Aging of Powder-Metallurgy Al Alloys

    Science.gov (United States)

    Blackburn, L. B.

    1987-01-01

    Report describes experimental study of thermal responses and aging behaviors of three new aluminum alloys. Alloys produced from rapidly solidified powders and contain 3.20 to 5.15 percent copper, 0.24 to 1.73 percent magnesium, 0.08 to 0.92 percent iron, and smaller amounts of manganese, nickel, titanium, silicon, and zinc. Peak hardness achieved at lower aging temperatures than with standard ingot-metallurgy alloys. Alloys of interest for automobile, aircraft, and aerospace applications.

  2. Effects of lubricant's friction coefficient on warm compaction powder metallurgy

    Institute of Scientific and Technical Information of China (English)

    LI Yuan-yuan; NGAI Tungwai Leo; WANG Shng-lin; ZHU Min; CHEN Wei-ping

    2005-01-01

    The correct use of lubricant is the key of warm compaction powder metallurgy.Different lubricants produce different lubrication effects and their optimal application temperature will be different.Three different lubricants were used to study the effects of friction coefficient on warm compaction process.Friction coefficients of these lubricants were measured at temperatures ranging from ambient temperature to 200 ℃.Iron-base samples were prepared using different processing temperatures and their green compact densities were studied.

  3. Colorful Chemistry

    Science.gov (United States)

    Sullivan, P. Teal; Carsten Conner, L. D.; Guthrie, Mareca; Pompea, Stephen; Tsurusaki, Blakely K.; Tzou, Carrie

    2017-01-01

    This article describes a chemistry/art activity that originated in an National Science Foundation--funded two-week STEAM (Science, Technology, Engineering, Art, and Math) academy for grade 4-6 girls. The authors recommend using this investigation in conjunction with other activities focusing on chemical change as a step toward fulfilling the…

  4. Measuring ocean acidification: new technology for a new era of ocean chemistry.

    Science.gov (United States)

    Byrne, Robert H

    2014-05-20

    Human additions of carbon dioxide to the atmosphere are creating a cascade of chemical consequences that will eventually extend to the bottom of all the world's oceans. Among the best-documented seawater effects are a worldwide increase in open-ocean acidity and large-scale declines in calcium carbonate saturation states. The susceptibility of some young, fast-growing calcareous organisms to adverse impacts highlights the potential for biological and economic consequences. Many important aspects of seawater CO2 chemistry can be only indirectly observed at present, and important but difficult-to-observe changes can include shifts in the speciation and possibly bioavailability of some life-essential elements. Innovation and invention are urgently needed to develop the in situ instrumentation required to document this era of rapid ocean evolution.

  5. Chemistry, technology, and nutraceutical functions of cumin (Cuminum cyminum L): an overview.

    Science.gov (United States)

    Sowbhagya, H B

    2013-01-01

    Cumin is a seed spice belonging to the family umbelliferae. Cumin and value added products from cumin are used in food flavoring and perfumery. Cumin contains volatile oil (3-4%), cuminaldehyde, the major active principle, which is present to an extent of 45-50%. Cumin and value added products from cumin, viz., cumin oil and oleoresin are exported. Cumin powder forms the main component of many spice mixes and curry powders. Cuminaldehyde is an important phytochemical and possesses many health benefits. Alcohol and water extract of cumin are reported to possess many nutraceutical properties like antiallergic, antioxidant, anti-platelet aggregation, and hypoglycemic. Cumin and value added products from cumin can be a good source of nutraceuticals with many biological activities. Incorporation of cumin into food products will have the benefits of a flavorant and nutraceutical at the same time. In the present review, the chemistry, processing, and biological activities of cumin and its components are discussed.

  6. Biomimetic surface modification of polypropylene by surface chain transfer reaction based on mussel-inspired adhesion technology and thiol chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Zhijun; Zhao, Yang; Sun, Wei; Shi, Suqing, E-mail: shisq@nwu.edu.cn; Gong, Yongkuan

    2016-11-15

    Highlights: • Biomimetic surface modification of PP was successfully conducted by integrating mussel-inspired technology, thiol chemistry and cell outer membranes-like structures. • The resultant biomimetic surface exhibits good interface and surface stability. • The obvious suppression of protein adsorption and platelet adhesion is also achieved. • The residue thoil groups on the surface could be further functionalized. - Abstract: Biomimetic surface modification of polypropylene (PP) is conducted by surface chain transfer reaction based on the mussel-inspired versatile adhesion technology and thiol chemistry, using 2-methacryloyloxyethylphosphorylcholine (MPC) as a hydrophilic monomer mimicking the cell outer membrane structure and 2,2-azobisisobutyronitrile (AIBN) as initiator in ethanol. A layer of polydopamine (PDA) is firstly deposited onto PP surface, which not only offers good interfacial adhesion with PP, but also supplies secondary reaction sites (-NH{sub 2}) to covalently anchor thiol groups onto PP surface. Then the radical chain transfer to surface-bonded thiol groups and surface re-initiated polymerization of MPC lead to the formation of a thin layer of polymer brush (PMPC) with cell outer membrane mimetic structure on PP surface. X-ray photoelectron spectrophotometer (XPS), atomic force microscopy (AFM) and water contact angle measurements are used to characterize the PP surfaces before and after modification. The protein adsorption and platelet adhesion experiments are also employed to evaluate the interactions of PP surface with biomolecules. The results show that PMPC is successfully grafted onto PP surface. In comparison with bare PP, the resultant PP-PMPC surface exhibits greatly improved protein and platelet resistance performance, which is the contribution of both increased surface hydrophilicity and zwitterionic structure. More importantly, the residue thiol groups on PP-PMPC surface create a new pathway to further functionalize such

  7. Incorporating spectroscopy and measurement technology into the high school chemistry laboratory

    Science.gov (United States)

    Harbert, Emily Ann

    Science and technology are becoming increasingly important in maintaining a healthy economy at home and a competitive edge on the world stage, though that is just one facet affected by inadequate science education in the United States. Engaging students in the pursuit of knowledge and giving them the skills to think critically are paramount. One small way to assist in achieving these goals is to increase the quality and variety of technology-rich activities conducted in high school classrooms. Incorporating more laboratory measurement technology into high schools may incite more student interest in the processes and practices of science and may allow students to learn to think more critically about their data and what it represents. The first objective of the work described herein was to determine what measurement technology is being used in schools and to what extent, as well as to determine other teacher needs and preferences. Second, the objective was to develop a new program to provide incoming freshmen (or rising seniors) with measurement technology training they did not receive in high school, and expose them to new research and career opportunities in science. The final objective was to create a technology-rich classroom laboratory activity for use in high schools.

  8. Machinability of Green Powder Metallurgy Components: Part II. Sintered Properties of Components Machined in Green State

    Science.gov (United States)

    Robert-Perron, Etienne; Blais, Carl; Pelletier, Sylvain; Thomas, Yannig

    2007-06-01

    The green machining process is virtually a must if the powder metallurgy (PM) industries are to solve the lower machining performances associated with PM components. This process is known for lowering the rate of tool wear. Recent improvements in binder/lubricant technologies have led to high-green-strength systems that enable green machining. Combined with the optimized cutting parameters determined in Part I of the study, the green machining of PM components seems to be a viable process for fabricating high performance parts on large scale and complete other shaping processes. This second part of our study presents a comparison between the machining behaviors and the sintered properties of components machined prior to or after sintering. The results show that the radial crush strength measured on rings machined in their green state is equal to that of parts machined after sintering.

  9. Machinability of Green Powder Metallurgy Components: Part I. Characterization of the Influence of Tool Wear

    Science.gov (United States)

    Robert-Perron, Etienne; Blais, Carl; Pelletier, Sylvain; Thomas, Yannig

    2007-06-01

    The green machining process is an interesting approach for solving the mediocre machining behavior of high-performance powder metallurgy (PM) steels. This process appears as a promising method for extending tool life and reducing machining costs. Recent improvements in binder/lubricant technologies have led to high green strength systems that enable green machining. So far, tool wear has been considered negligible when characterizing the machinability of green PM specimens. This inaccurate assumption may lead to the selection of suboptimum cutting conditions. The first part of this study involves the optimization of the machining parameters to minimize the effects of tool wear on the machinability in turning of green PM components. The second part of our work compares the sintered mechanical properties of components machined in green state with other machined after sintering.

  10. New evidence for prehistoric copper metallurgy in the vicinity of Bor

    Directory of Open Access Journals (Sweden)

    Kapuran Aleksandar

    2016-01-01

    Full Text Available The last three years of archaeological investigations at the site Ru`ana in Banjsko Polje, in the immediate vicinity of Bor, have provided new evidence regarding the role of non-ferrous metallurgy in the economy of the prehistoric communities of north-eastern Serbia. The remains of metallurgical furnaces and a large amount of metallic slags at two neighbouring sites in the mentioned settlement reveal that locations with many installations for the thermal processing of copper ore existed in the Bronze Age. We believe, judging by the finds of material culture, that metallurgical activities in this area also continued into the Iron Age and, possibly, into the 4th century AD. [Projekat Ministarstva nauke Republike Srbije, br. 177020: Archaeology of Serbia: Cultural identity, integration factors, technological processes and the role of the central Balkans in the development of European prehistory

  11. Beryllium chemistry and processing

    CERN Document Server

    Walsh, Kenneth A

    2009-01-01

    This book introduces beryllium; its history, its chemical, mechanical, and physical properties including nuclear properties. The 29 chapters include the mineralogy of beryllium and the preferred global sources of ore bodies. The identification and specifics of the industrial metallurgical processes used to form oxide from the ore and then metal from the oxide are thoroughly described. The special features of beryllium chemistry are introduced, including analytical chemical practices. Beryllium compounds of industrial interest are identified and discussed. Alloying, casting, powder processing, forming, metal removal, joining and other manufacturing processes are covered. The effect of composition and process on the mechanical and physical properties of beryllium alloys assists the reader in material selection. The physical metallurgy chapter brings conformity between chemical and physical metallurgical processing of beryllium, metal, alloys, and compounds. The environmental degradation of beryllium and its all...

  12. The Mechanical Metallurgy of Armour Steels

    Science.gov (United States)

    2016-10-01

    1 armour in MIL-A-12560K. Class 2 260-310 Class 2 armour is intended for use in those areas where maximum resistance to failure under conditions of......Technology Group DST-Group-TR-3305 ABSTRACT Armour steels have historically delivered optimised ballistic performance against a range of

  13. National information service in mining, mineral processing and extractive metallurgy. [MINTEC

    Energy Technology Data Exchange (ETDEWEB)

    Romaniuk, A.S.; MacDonald, R.J.C.

    1979-03-01

    More than a dedade ago, CANMET management recognized the need to make better use of existing technological information in mining and extractive metallurgy, two fields basic to the economic well-being of Canada. There were at that time no indexes or files didicated to disseminating technical information for the many minerals mined and processed in Canada, including coal. CANMET, with the nation's largest research and library resources in the minerals field, was in a unique position to fill this need. Initial efforts were concentrated on building a mining file beginning with identification of world sources of published information, development of a special thesaurus of terms for language control and adoption of a manual indexing/retrieval system. By early 1973, this file held 8,300 references, with source, abstract and keywords given for each reference. In mid-1973, operations were computerized. Software for indexing and retrieval by batch mode was written by CANMET staff to utilize the hardware facilities of EMR's Computer Science Center. The resulting MINTEC file, one of the few files of technological information produced in Canada, is the basis for the national literature search service in mining offered by CANMET. Attention is now focussed on building a sister-file in extractive metallurgy using the system already developed. Published information sources have been identified and a thesaurus of terms is being compiled and tested. The software developed for CANMET's file-building operations has several features, including the selective dissemination of information and production from magnetic tape of photoready copy for publication, as in a bi-monthly abstracts journal.

  14. Annual Review on Yunnan Metallurgy in 2012%2012年云南冶金年评

    Institute of Scientific and Technical Information of China (English)

    谢刚; 田林

    2013-01-01

    Based on the papers by metallurgical researchers in Yunnan in 2012, the production, scientific research and technology on metallurgy of Yunnan ferrous metal, nonferrous metal, semimetal, rare metal and noble metal are summarized.%依据2012年云南冶金科技工作者发表的文献资料,对该年度云南黑色金属冶金、有色金属冶金、半金属及稀有金属冶金和贵金属生产、科研及技术进行了评述.

  15. Examining the Use of Adaptive Technologies to Increase the Hands-On Participation of Students with Blindness or Low Vision in Secondary-School Chemistry and Physics

    Science.gov (United States)

    Supalo, Cary A.; Humphrey, Jennifer R.; Mallouk, Thomas E.; Wohlers, H. David; Carlsen, William S.

    2016-01-01

    To determine whether a suite of audible adaptive technologies would increase the hands-on participation of high school students with blindness or low vision in chemistry and physics courses, data were examined from a multi-year field study conducted with students in mainstream classrooms at secondary schools across the United States. The students…

  16. Unraveling the mysteries of microwave chemistry using silicon carbide reactor technology.

    Science.gov (United States)

    Kappe, C Oliver

    2013-07-16

    In the past few years, the use of microwave energy to heat chemical reactions has become an increasingly popular theme in the scientific community. This nonclassical heating technique has slowly progressed from a laboratory curiosity to an established method commonly used both in academia and in industry. Because of its efficiency, microwave heating dramatically reduces reaction times (from days and hours to minutes and seconds) and improves product purities or material properties among other advantages. Since the early days of microwave chemistry, researchers have observed rate-accelerations and, in some cases, altered product distributions as compared with reactions carried out using classical oil-bath heating. As a result, researchers have speculated that so-called specific or nonthermal microwave effects could be responsible for these differences. Much of the debate has centered on the question of whether the electromagnetic field can exert a direct influence on a chemical transformation outside of the simple macroscopic change in bulk reaction temperature. In 2009, our group developed a relatively simple "trick" that allows us to rapidly evaluate whether an observed effect seen in a microwave-assisted reaction results from a purely thermal phenomenon, or involves specific or nonthermal microwave effects. We use a microwave reaction vessel made from silicon carbide (SiC) ceramic. Because of its high microwave absorptivity, the vessel shields its contents from the electromagnetic field. As a result, we can easily mimic a conventionally heated autoclave experiment inside a microwave reactor under carefully controlled reaction conditions. The switch from an almost microwave transparent glass (Pyrex) to a strongly microwave absorbing SiC reaction vial under otherwise identical reaction conditions (temperature profiles, pressure, stirring speed) then allows us to carefully evaluate the influence of the electromagnetic field on the particular chemical transformation

  17. Cooperation of the Institute of Industrial Chemistry with a petroleum refinery at Plotska for the purpose of modernizing the technology for producing aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Tecza, U.; Lisicki, Z.; Manka, S.; Mierzejewski, M.; Prakhmajer, A.

    1982-01-01

    A project of the technological system of a unit for producing aromatic hydrocarbons at a petroleum refinery in Plotska and projects to modernize the technological processes in the production of aromatic hydrocarbons which are related to it is examined. These projects were carried out by colleagues of Institute of Industrial Chemistry (Warsaw) at the plant in 1974-80. They led to intensification of the production of xylenes and to the production of new products.

  18. Factors associated with computer and Internet technology implementation in biology, chemistry, and physics education in Turkish secondary schools

    Science.gov (United States)

    Ozer, Melike

    The main purposes of the research were to identify computer and Internet use by biology, chemistry and physics teachers in Turkish secondary schools and identify factors associated with computer and Internet technology. To this end, survey documents were sent by the Provincial Directorate of National Education to 250 selected schools' administrators for further distribution. Administrators were asked to complete the "Computer and Internet Use: School Survey," and to distribute the "Science Teacher Computer and Internet Use" surveys to the two teachers who teach science class. Surveys were then returned to the General Directorate of Educational Technologies. Research findings showed that computer and Internet use has not occurred effectively. Computers were first introduced to Turkish schools in 1984; unfortunately the current situation of computer and Internet use in science education is not at the projected earlier point in time. Considering the fact that science teachers' participation in technology-related professional development program is higher than other subject teachers, the use of computer and Internet technologies in Turkish secondary schools is still at its early stages. Lack of computer knowledge and not knowing how to integrate computers into education were the major factors reported. With regard to computer and Internet use, a regression model for Turkish schools, which includes access and knowledge, explains a large part of the variance in study results. There was a significant relationship between computer attitude (computer liking, usefulness, and confidence) and computer and Internet use. Although there was a significant negative relationship between Internet and computer uses and the attitudinal component, computer anxiety, it did not deter individuals from expressing a desire to engage in computer use in education.

  19. The Chemistry and Technology of Furfural Production in Modern Lignocellulose-Feedstock Biorefineries

    NARCIS (Netherlands)

    Marcotullio, G.

    2011-01-01

    This dissertation deals with biorefinery technology development, i.e. with the development of sustainable industrial methods aimed at the production of chemicals, fuels, heat and power from lignocellulosic biomass. This work is particularly focused on the production of furfural from hemicellulose-de

  20. Student Perceptions of Chemistry Experiments with Different Technological Interfaces: A Comparative Study

    Science.gov (United States)

    Priest, Samuel J.; Pyke, Simon M.; Williamson, Natalie M.

    2014-01-01

    Microcomputer based laboratory activities have been suggested to have a number of benefits in science education. However, their implementation produces mixed results, and student perception data have in the past yielded responses that are negative regarding the technology. This work presents a case study of three first year undergraduate chemistry…

  1. Diversifying Science, Technology, Engineering, and Mathematics (STEM): An Inquiry into Successful Approaches in Chemistry

    Science.gov (United States)

    Wilson, Zakiya S.; McGuire, Saundra Y.; Limbach, Patrick A.; Doyle, Michael P.; Marzilli, Luigi G.; Warner, Isiah M.

    2014-01-01

    For many years, the U.S. has underutilized its human resources, as evidenced by the pervasive underrepresentation of several racial and ethnic groups within academia in general and the science, technology, engineering, and mathematics (STEM) disciplines, in particular. To address this underutilization, academic departments within U.S. universities…

  2. Thirty-seventh ORNL/DOE conference on analytical chemistry in energy technology: Abstracts of papers

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    Abstracts only are given for papers presented during the following topical sessions: Opportunities for collaboration: Industry, academic, national laboratories; Developments in sensor technology; Analysis in containment facilities; Improving the quality of environmental data; Process analysis; Field analysis; Radiological separations; Interactive analytical seminars; Measurements and chemical industry initiatives; and Isotopic measurements and mass spectroscopy.

  3. Chemistry, technology, and nutraceutical functions of celery (Apium graveolens L.): an overview.

    Science.gov (United States)

    Sowbhagya, H B

    2014-01-01

    Celery is a commercially important seed spice belonging to the family Umbelliferrae. Celery is used in various forms such as fresh herb, stalk, seeds, oil, and oleoresin for flavoring of foods and for medicinal purposes. Celery seed contains 2% volatile oil that finds application for flavoring of foods and also in perfumery industry. Limonene and selinene form about 60% and 20% of the oil, respectively. However, the important flavor constituents of the oil responsible for the typical aroma are 3-n-butyl-4-5-dihydrophthalide (sedanenolide), 3-n-butyl phthalide, sedanolide, and sedanonic anhydride present in very low levels (1-3%). Celery contains 15% fatty oil with the fatty acids: petroselenic (64.3%), oleic (8.1%), linoleic (18%), linolenic (0.6%), and palmitic acids. Phthalides especially sedanenaloide possess many health benefits. Celery extracts are reported to possess many nutraceutical properties, viz., antioxidant, hypolipidemic, hypoglycemic, and anti-platelet aggregation. In the present review, the chemistry, processing, and biological activities of celery and the components responsible are discussed.

  4. Toxicology and occupational hazards of new materials and processes in metal surface treatment, powder metallurgy, technical ceramics, and fiber-reinforced plastics.

    Science.gov (United States)

    Midtgård, U; Jelnes, J E

    1991-12-01

    Many new materials and processes are about to find their way from the research laboratory into industry. The present paper describes some of these processes and provides an overview of possible occupational hazards and a list of chemicals used or produced in the processes. The technological areas that are considered are metal surface treatment (ion implantation, physical and chemical vapor deposition, plasma spraying), powder metallurgy, advanced technical ceramics, and fiber-reinforced plastics.

  5. Magnetism and metallurgy of soft magnetic materials

    CERN Document Server

    Chen, Chih-Wen

    2011-01-01

    Soft magnetic materials are economically and technologically the most important of all magnetic materials. In particular, the development of new materials and novel applications for the computer and telecommunications industries during the past few decades has immensely broadened the scope and altered the nature of soft magnetic materials. In addition to metallic substances, nonmetallic compounds and amorphous thin films are coming increasingly important. This thorough, well-organized volume - on of the most comprehensive treatments available - offers a coherent, logical presentation of the p

  6. Information technology in chemistry research and education: Part I. Ab initio studies on the hydrolysis of aromatic diazonium ions. Part II. Theoretical study and molecular modeling of non-covalent interactions. Part III. Applying information technology in chemistry education

    Science.gov (United States)

    Wu, Zhengyu

    Part I of this dissertation studies the bonding in chemical reactions, while Part II studies the bonding related to inter- and intra-molecular interactions. Part III studies the application of IT technology in chemistry education. Part I of this dissertation (chapter 1 and chapter 2) focuses on the theoretical studies on the mechanism of the hydrolysis reactions of benzenediazonium ion and guaninediazonium ion. The major conclusion is that in hydrolysis reactions the "unimolecular mechanism" actually has to involve the reacting solvent molecule. Therefore, the unimolecular pathway can only serve as a conceptual model but will not happen in the reality. Chapter I concludes that the hydrolysis reaction of benzenediazonium ion takes the direct SN2Ar mechanism via a transition state but without going through a pre-coordination complex. Chapter 2 concludes that the formation of xanthine from the dediazoniation reaction of guaninediazonium ion in water takes the SN2Ar pathway without a transition state. And oxanine might come from an intermediate formed by the bimolecular deprotonation of the H atom on N3 of guaninediazonium ion synchronized with the pyrimidine ring opening reaction. Part II of this dissertation includes chapters 3, 4, and 5. Chapter 3 studies the quadrupole moment of benzene and quadrupole-quadrupole interactions. We concluded that the quadrupole-quadrupole interaction is important in the arene-arene interactions. Our study shows the most stable structure of benzene dimer is the point-to-face T-shaped structure. Chapter 4 studies the intermolecular interactions that result in the disorder of the crystal of 4-Chloroacetophenone-(4-methoxyphenylethylidene). We analyzed all the nearest neighbor interactions within that crystal and found that the crystal structure is determined by its thermo-dynamical properties. Our calculation perfectly reproduced the percentage of parallel-alignment of the crystal. Part III of this dissertation is focused on the

  7. InCom '91. Instrumentalized analytical chemistry and computer technology

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, W.; Matthes, J.P.; Perkampus, H.H. (eds.)

    1991-01-01

    This volume contains 129 short communications on the following subjects: Computer technology, clinical analysis, biochemical analysis, environmental analysis, chiral separations, gas chromatography, HPLC, ion chromatography, supercritical fluid chromatography, HPTLC, electrophoresis, sample preparation, atomic spectroscopy, elemental analysis, UV spectroscopy, IR spectroscopy, NMR spectroscopy, mass spectrometry, electrochemisty, GC-MS, HPLC-MS, sensors, technical analysis, water treatment. 32 records have been documented for this database. (BBR).

  8. Chemogenomics: a discipline at the crossroad of high throughput technologies, biomarker research, combinatorial chemistry, genomics, cheminformatics, bioinformatics and artificial intelligence.

    Science.gov (United States)

    Maréchal, Eric

    2008-09-01

    Chemogenomics is the study of the interaction of functional biological systems with exogenous small molecules, or in broader sense the study of the intersection of biological and chemical spaces. Chemogenomics requires expertises in biology, chemistry and computational sciences (bioinformatics, cheminformatics, large scale statistics and machine learning methods) but it is more than the simple apposition of each of these disciplines. Biological entities interacting with small molecules can be isolated proteins or more elaborate systems, from single cells to complete organisms. The biological space is therefore analyzed at various postgenomic levels (genomic, transcriptomic, proteomic or any phenotypic level). The space of small molecules is partially real, corresponding to commercial and academic collections of compounds, and partially virtual, corresponding to the chemical space possibly synthesizable. Synthetic chemistry has developed novel strategies allowing a physical exploration of this universe of possibilities. A major challenge of cheminformatics is to charter the virtual space of small molecules using realistic biological constraints (bioavailability, druggability, structural biological information). Chemogenomics is a descendent of conventional pharmaceutical approaches, since it involves the screening of chemolibraries for their effect on biological targets, and benefits from the advances in the corresponding enabling technologies and the introduction of new biological markers. Screening was originally motivated by the rigorous discovery of new drugs, neglecting and throwing away any molecule that would fail to meet the standards required for a therapeutic treatment. It is now the basis for the discovery of small molecules that might or might not be directly used as drugs, but which have an immense potential for basic research, as probes to explore an increasing number of biological phenomena. Concerns about the environmental impact of chemical industry

  9. WikiHyperGlossary (WHG): an information literacy technology for chemistry documents.

    Science.gov (United States)

    Bauer, Michael A; Berleant, Daniel; Cornell, Andrew P; Belford, Robert E

    2015-01-01

    The WikiHyperGlossary is an information literacy technology that was created to enhance reading comprehension of documents by connecting them to socially generated multimedia definitions as well as semantically relevant data. The WikiHyperGlossary enhances reading comprehension by using the lexicon of a discipline to generate dynamic links in a document to external resources that can provide implicit information the document did not explicitly provide. Currently, the most common method to acquire additional information when reading a document is to access a search engine and browse the web. This may lead to skimming of multiple documents with the novice actually never returning to the original document of interest. The WikiHyperGlossary automatically brings information to the user within the current document they are reading, enhancing the potential for deeper document understanding. The WikiHyperGlossary allows users to submit a web URL or text to be processed against a chosen lexicon, returning the document with tagged terms. The selection of a tagged term results in the appearance of the WikiHyperGlossary Portlet containing a definition, and depending on the type of word, tabs to additional information and resources. Current types of content include multimedia enhanced definitions, ChemSpider query results, 3D molecular structures, and 2D editable structures connected to ChemSpider queries. Existing glossaries can be bulk uploaded, locked for editing and associated with multiple social generated definitions. The WikiHyperGlossary leverages both social and semantic web technologies to bring relevant information to a document. This can not only aid reading comprehension, but increases the users' ability to obtain additional information within the document. We have demonstrated a molecular editor enabled knowledge framework that can result in a semantic web inductive reasoning process, and integration of the WikiHyperGlossary into other software technologies, like

  10. CURRENT STATE AND TENDENCIES OF DEVELOPMENT OF FERROUS METALLURGY IN THE EAEU COUNTRIES

    Directory of Open Access Journals (Sweden)

    N. P. Dragun

    2016-01-01

    Full Text Available The analysis of modern status and tendencies of development of ferrous metallurgy in the countries of the EAEU is described in the article. On the basis of the conducted analysis are revealed the identified systemic problems of metallurgy and the conclusions on possible ways of their solution using the potential of integration are given.

  11. Effectiveness of use of Nanostructure Minerals – Bentonite of Taganskiy Deposit for Waste Water Clearing in Metallurgy Industry

    Directory of Open Access Journals (Sweden)

    Sharbanu Muzdybayeva

    2014-10-01

    Full Text Available The currently used traditional method of waste water treatment based on the precipitation of heavy metals by iron hydroxide formed at the time of neutralization (liming / bleach(active chlorine doesn’t correspondent to the standards of maximum permissible concentration (MPC in practical meaning. In this regard, the urgent task is the use of natural materials as sorbents due to the relatively high sorption capacity, selectivity, having cation-exchange properties and the possibility of almost complete removal of heavy metal ions. Another important factor is their relatively low cost and availability (sometimes as alocal material. We believe that the use of scientific-based combinations of different ways in waste water treatment based on the success of modern chemistry allows opening newand perspective opportunities in this area.Key Words: Waste Water, Metallurgy, Bentonite, Zeolites, Groundwater

  12. Impact of surface chemistry

    OpenAIRE

    2010-01-01

    The applications of molecular surface chemistry in heterogeneous catalyst technology, semiconductor-based technology, medical technology, anticorrosion and lubricant technology, and nanotechnology are highlighted in this perspective. The evolution of surface chemistry at the molecular level is reviewed, and the key roles of surface instrumentation developments for in situ studies of the gas–solid, liquid–solid, and solid–solid interfaces under reaction conditions are emphasized.

  13. Impact of surface chemistry

    Science.gov (United States)

    Somorjai, Gabor A.; Li, Yimin

    2011-01-01

    The applications of molecular surface chemistry in heterogeneous catalyst technology, semiconductor-based technology, medical technology, anticorrosion and lubricant technology, and nanotechnology are highlighted in this perspective. The evolution of surface chemistry at the molecular level is reviewed, and the key roles of surface instrumentation developments for in situ studies of the gas–solid, liquid–solid, and solid–solid interfaces under reaction conditions are emphasized. PMID:20880833

  14. Research Progress and Application of the Microwave Technology in Organic Chemistry%微波有机化学的应用与研究进展分析

    Institute of Scientific and Technical Information of China (English)

    蔡玉鑫

    2014-01-01

    With the development of science and technology, the contemporary society puts forward the concept of"green chemistry"in chemistry and chemical related fields, which not only demands economic development, but also demands to protect the environment. With wide application of the microwave technology in the field of chemistry, especially organic chemistry, the problems of traditional heating methods have been solved, such as long heating time, high requirement for equipments, complex operation process, and low reaction yield and so on. In this paper, the principle of microwave technology was introduced, and research progress and application of the microwave technology in organic chemistry were discussed.%随着科技的进步和文明的发展,当代社会对化工和化学相关领域提出了“绿色化学”的概念,要求既要经济发展,也要保护环境。随着微波技术在化学领域中的广泛应用,在化学反应中,尤其是有机化学的反应中,传统的加热手段所带来的时间冗长、设备要求太高、操作过程复杂、反应收率不高等问题,都得到了有效的解决。介绍了微波技术的原理,并举例说明了微波技术在有机化学中的应用与研究进展。

  15. Kosovo mining, metallurgy, and politics: eight centuries of perspective;

    Energy Technology Data Exchange (ETDEWEB)

    Vukovic, M.; Weinstein, A. [University of Idaho, Moscow, ID (United States). Environmental Science Programme

    2002-05-01

    This article presents a short history of the Kosovo mining-metallurgy industry within the course of the last 800 years. Kosovo, as a relatively small piece of land in the Balkans, contains that region's highest concentration of mineral wealth (silver, lead, zinc, tin, coal). This paper explains the social and political impacts of metal production in medieval Serbia, the Ottoman Empire, and Yugoslavia. The recent clashes between Serbs and Albanians are viewed in the light of the 'geopolitics of minerals.'

  16. Effect of Die Wall Lubrication on Warm Compaction Powder Metallurgy

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Die wall lubrication was applied on warm compaction powder metallurgy in hope to reduce the concentration level of the admixed lubricant since lubricant is harmful to the mechanical property of the sintered materials. Iron-based samples were prepared by die wall lubricated warm compaction at 135 ℃ and 175 ℃, using polytetrafluoroethylene (PTFE) emulsion as die wall lubricant. A compacting pressure of 700 MPa and 550 MPa were used. The admixed lubricant concentration ranging from 0 to 0.6 wt.% was used in th...

  17. Welding Metallurgy and Processing Issues for Joining of Power Sources

    Energy Technology Data Exchange (ETDEWEB)

    Lienert, Thomas J. [Los Alamos National Laboratory; Reardon, Patrick T. [Los Alamos National Laboratory

    2012-08-14

    Weldability issues with the pertinent alloys have been reviewed and preliminary results of our work on Haynes 25 have been presented. Further results on the mechanical properties and metallography on the EB welds are imminent. Hot-ductility experiments will commence within a few weeks. Aging studies on the effects of heat treatment using the Gleeble are also planned. MST-6 has extensive background in the welding metallurgy of the pertinent alloys. We also have considerable experience with the various welding processes to be used.

  18. Application of the gel casting process in iron powder metallurgy

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The effects of various gel casting process parameters such as the dispersant and solid loading on the rheology of Fe slurries, molding, and sintering behaviors were studied. The relationship between solid loading and viscidity in the process of iron base powder metallurgy was researched to obtain better microstructure and properties. The results showed that the viscosity of Fe slurries is obviously reduced with the increase of the dispersant. The suitable parameters are as follows: the solid loading is 61% and sintering temperature is 1180℃. Iron parts with relatively high density and better properties were obtained by the gel casting process.

  19. Properties of porous magnesium prepared by powder metallurgy.

    Science.gov (United States)

    Čapek, Jaroslav; Vojtěch, Dalibor

    2013-01-01

    Porous magnesium-based materials are biodegradable and promising for use in orthopaedic applications, but their applications are hampered by their difficult fabrication. This work reports the preparation of porous magnesium materials by a powder metallurgy technique using ammonium bicarbonate as spacer particles. The porosity of the materials depended on the amount of ammonium bicarbonate and was found to have strong negative effects on flexural strength and corrosion behaviour. However, the flexural strength of materials with porosities of up to 28 vol.% was higher than the flexural strength of non-metallic biomaterials and comparable with that of natural bone.

  20. Iron's Role in Aluminum: A Powder Metallurgy and Sustainability Approach

    Science.gov (United States)

    Saller, Brandon Dale

    The family of Al-Fe alloys is both scientifically and technologically interesting for several reasons. First, the low equilibrium solid solubility (0.03 at.%) and diffusivity of Fe in Al suggest that the alloys containing these two elements should be thermally stable. Many studies have tried to extend this low solubility value via non-equilibrium processing routes. Second, published results suggest that there is a range of intermetallic phases, including the metastable orthorhombic Al6Fe and the equilibrium monoclinic Al13Fe4, for example, the formation of which depends on solidification and subsequent processing conditions. Third, from a sustainability standpoint, both Al and Fe are present in bauxite (aluminum ore), however up to 40 wt.% Fe-oxide present in bauxite is discarded as a waste product, creating red mud pits. In order to understand the multiple facets and implications of iron's role in aluminum, a systematic investigation was performed into the precipitates that form as a function of thermal exposure and their subsequent effect on the tensile behavior of the alloy. In this study, Al-2at.% Fe and Al-5at.% Fe powders were synthesized via helium gas atomization and argon gas atomization, respectively. Cooling rates upwards of 106 K/s were achieved resulting in an intermetallic-free starting structure. Powders were subsequently severely plastically deformed via either cryomilling or high-pressure torsion to obtain nanostructured/ultrafine-grained powder or a consolidated specimen, respectively. Characterization via electron microscopy established a map of the powder microstructure as a function of atomization cooling rate. In addition, electron backscatter diffraction revealed a large number of low-angle grain boundaries, which influenced nucleation and precipitation of the metastable Al6Fe phase. X-ray diffraction and atom probe tomography results provide the most comprehensive evidence to date of forcing of 2at.% Fe into solution with the Al matrix via

  1. Recent applications of PIXE spectrometry in archaeology. Pt. 1; Observations on the early development of copper metallurgy in the Old World

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, S.J. (MASCA, Univ. Museum, Univ. Pennsylvania, Philadelphia, PA (United States)); Swann, C.P. (Bartol Research Inst., Univ. Delaware, Newark, DE (United States))

    1993-04-01

    The early development of copper metallurgy can be characterized by three steps of innovation: (i) Exploitation of native copper resources for simple tool-making as early as the 7th millennium B.C. in the Near East; (ii) the recovery of copper metal from minerals such as malachite, by smelting, during the 5th millennium B.C., both in the Near East and in eastern Europe; and (iii) the deliberate alloying of copper and tin, to make bronze, circa 2800 B.C. in Mesopotamia (modern Iraq). This paper reviews the technological aspects associated the first two of these steps, comparing compositional patterns (as determined by PIXE spectrometry) for the copper metallurgy of various regions including the Middle Danube basin, the Tigris basin, and the Iranian Plateau. (orig.).

  2. 宏基因组学技术在生物冶金中的应用%Application of Metagenomic Technique in Biological Metallurgy

    Institute of Scientific and Technical Information of China (English)

    冯光志; 石玉; 邱朝坤; 喻弘; 舒玉凤

    2015-01-01

    The development status of biological metallurgy and the factors restricting its popularization and application were outlined,the application of metagenomics technology in biological metallurgy was described in detail,especially its application in the exploitation of bioming microbial resources,the revelation of population relationship about bioming microbial community,the acquisition of exogenous function gene and the research of resistance mechanism about bioming microbes.The prospects of metagenomics technology on promoting the development of biological metallurgy research were forecasted.%介绍了生物冶金的发展概况以及制约其推广应用的因素,阐述了宏基因组学技术在生物冶金中的应用,包括在开发新的浸矿微生物资源、揭示浸矿微生物群落种群关系、获取外源功能基因和在浸矿微生物抗性机制研究中的应用,展示了宏基因组学技术推动生物冶金研究发展的巨大潜力。

  3. Capsicum--production, technology, chemistry, and quality--Part II. Processed products, standards, world production and trade.

    Science.gov (United States)

    Govindarajan, V S

    1986-01-01

    Capsicums, as a spice, have been known since the beginning of civilization and historically associated with the discovery of the New World. The genus Capsicum (Fam. Solanaceae) provides many varieties and adds color, pungency, and aroma to the cuisines of most of the world. From the pungent chilli, of interest also to pharmaceuticals, to the colorful paprika and the bell capsicums with its remarkable aroma, the genus has been of great interest for its chemistry and physiological action. Pungency as a sensory attribute, its evaluation, structure-activity relationship, and its increasing acceptance and preference by diverse populations of the world are of great interest to many research disciplines. In a comprehensive review of all aspects in four sequential parts, Part I deals with History, Botany, Cultivation, and Primary Processing (CRC Critical Review, Food Science and Nutrition). The Capsicums among the spices are second only to black pepper in trades both in volume and value. The production of the different forms of this spice as ground, specialty seasonings, and as the concentrated oleoresins through technologically advanced processes, proposed newer products, the standard to control quality of the different products, world production, trade, and prospects are reviewed in detail in this, Part II.

  4. Biomimetic surface modification of polypropylene by surface chain transfer reaction based on mussel-inspired adhesion technology and thiol chemistry

    Science.gov (United States)

    Niu, Zhijun; Zhao, Yang; Sun, Wei; Shi, Suqing; Gong, Yongkuan

    2016-11-01

    Biomimetic surface modification of polypropylene (PP) is conducted by surface chain transfer reaction based on the mussel-inspired versatile adhesion technology and thiol chemistry, using 2-methacryloyloxyethylphosphorylcholine (MPC) as a hydrophilic monomer mimicking the cell outer membrane structure and 2,2-azobisisobutyronitrile (AIBN) as initiator in ethanol. A layer of polydopamine (PDA) is firstly deposited onto PP surface, which not only offers good interfacial adhesion with PP, but also supplies secondary reaction sites (-NH2) to covalently anchor thiol groups onto PP surface. Then the radical chain transfer to surface-bonded thiol groups and surface re-initiated polymerization of MPC lead to the formation of a thin layer of polymer brush (PMPC) with cell outer membrane mimetic structure on PP surface. X-ray photoelectron spectrophotometer (XPS), atomic force microscopy (AFM) and water contact angle measurements are used to characterize the PP surfaces before and after modification. The protein adsorption and platelet adhesion experiments are also employed to evaluate the interactions of PP surface with biomolecules. The results show that PMPC is successfully grafted onto PP surface. In comparison with bare PP, the resultant PP-PMPC surface exhibits greatly improved protein and platelet resistance performance, which is the contribution of both increased surface hydrophilicity and zwitterionic structure. More importantly, the residue thiol groups on PP-PMPC surface create a new pathway to further functionalize such zwitterion modified PP surface.

  5. Interstitial control in titanium alloys produced by powder metallurgy

    Energy Technology Data Exchange (ETDEWEB)

    Henriques, V.A.R.; Petroni, S.L.G.; Cairo, C.A.A. [Instituto de Aeronautica e Espaco (AMR/CTA/IAE), Sao Jose dos Campos, SP (Brazil). Centro Tecnico Aeroespacial. Divisao de Materiais; Paula, M.S.M.; Galvani, E.T., E-mail: vinicius@iae.cta.br, E-mail: slpetroni@iae.cta.br, E-mail: Matheus@gmx.com, E-mail: ccairo@iae.cta.br, E-mail: eduardotgalvani@yahoo.com.br [Instituto Tecnologico de Aeronautica (ITA/CTA), Sao Jose dos Campos, SP (Brazil). Centro Tecnico Aeroespacial

    2009-07-01

    The titanium alloys are used for applications that demand high performance, including surgical implants and aerospace applications. Powder metallurgy is an advantageous alternative for titanium parts production with complex geometries at a relative low cost. Despite that, it is verified that the introduction of interstitial elements (oxygen, nitrogen and carbon) wile processing these alloys, though can increase hardness and mechanical resistance, which is frequently related to the reduction of ductility and fragility increase. The objective of this work is to investigate the influence of the interstitial elements in commercially pure Ti and Ti-{sup 13}Nb-{sup 13}Zr alloy produced by powder metallurgy (P/M). Samples were produced by the mixing of hydride metallic powders followed by uniaxial and cold isostatic pressing with subsequent densification by sintering at 1400 °C, in vacuum. Sintered samples were characterized for phase composition, microstructure and microhardness by X-ray diffraction, scanning electron microscopy and Vickers indentation, respectively. The interstitial content was analysed by Leco equipment. It was shown that the samples were sintered to high densities with a Widmanstatten microstructure. The oxygen and nitrogen contents are above the ELI (Extra Low Interstitial) and the critical issues were identified in the original blended elemental route. (author)

  6. Surface chemistry essentials

    CERN Document Server

    Birdi, K S

    2013-01-01

    Surface chemistry plays an important role in everyday life, as the basis for many phenomena as well as technological applications. Common examples range from soap bubbles, foam, and raindrops to cosmetics, paint, adhesives, and pharmaceuticals. Additional areas that rely on surface chemistry include modern nanotechnology, medical diagnostics, and drug delivery. There is extensive literature on this subject, but most chemistry books only devote one or two chapters to it. Surface Chemistry Essentials fills a need for a reference that brings together the fundamental aspects of surface chemistry w

  7. Cost-effective blended elemental powder metallurgy of titanium alloys for transportation application

    Energy Technology Data Exchange (ETDEWEB)

    Ivasishin, O.M.; Demidik, A.N.; Savvakin, D.G. [AN Ukrainskoj SSR, Kiev (Ukraine). Inst. Fiziki Metallov; Anokhin, V.M. [State Research and Design Titanium Inst., Zaporozhie (Ukraine)

    2000-07-01

    Transportation industry is one of the perspective areas of application for lightweight advanced materials, including titanium alloys. However, despite the excellent mechanical properties and corrosion resistance of titanium alloys, automobile and other transportation industries cannot afford titanium unless its cost is significantly reduced. Near-net-shape processings, amongst which are powder metallurgy (PM) techniques, look the most appealing ways of cost reduction. Economic potentiality of titanium PM processes depends on the availability of low-cost powder and particular consolidation technology used. In this paper the blended elemental technology by a simple press-and-sinter method has been investigated using various titanium powders, in order to find if this technology can be applied to production of parts from titanium alloys for transportation industry. Main part of work was done on Ti-6Al-4V (wt.%) composition although some other compositions were tried. Chemical and dimensional characteristics of initial powders, cold-compaction pressure, temperature and time of sintering were main variables of the study. It was shown that at proper choice of elemental constituents and consolidation parameters high density of the final product (98% of theoretical) could be obtained. For this case, microstructural investigations showed a phase and structural homogeneity of the synthesized material. This can give rise to the mechanical properties to be comparable with those of cast and wrought material. (orig.)

  8. Pedagogy-Based-Technology and Chemistry Students' Performance in Higher Institutions: A Case of Debre Berhan University

    Science.gov (United States)

    Demissie, Tesfaye; Ochonogor, Chukunoye E.; Engida, Temechegn

    2011-01-01

    Many students have difficulty in learning abstract and complex lessons of chemistry. This study investigated how students develop their understandings of abstract and complex lessons in chemistry with the aid of visualizing tools: animation, simulation and video that allow them to build clear concepts. Animation, simulation and video enable…

  9. Metallurgy of mercury in Almaden: from aludel furnaces until Pacific furnaces; La metalurgia del mercurio en Almaden: desde los hornos de aludeles a los hornos Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Tejero-Manzanares, J.; Garrido Saenz, I.; Mata Cabrera, F.; Rubio Mesas, M. L.

    2014-07-01

    This paper shows the different types of furnaces for roasting cinnabar, used in the metallurgy of quicksilver over the centuries of exploitation of the Almaden Mines (Spain). Some of these techniques are part of our industrial heritage. They have contributed to name UNESCO World Heritage Site the vast technological legacy of these mines recently. This research contributes to close the long way of metallurgical activity from aludel furnaces until Pacif furnaces, first and lasted technology to produce on an industrial scale. It is delved into the most relevant aspects having to do with the type, evolution and number of furnaces existing on each of the periods. (Author)

  10. N18, powder metallurgy superalloy for disks: Development and applications

    Energy Technology Data Exchange (ETDEWEB)

    Guedou, J.Y.; Lautridou, J.C.; Honnorat, Y. (SNECMA, Evry (France). Materials and Processes Dept.)

    1993-08-01

    The preliminary industrial development of a powder metallurgy (PM) superalloy, designated N18, for disk applications has been completed. This alloy exhibits good overall mechanical properties after appropriate processing of the material. These properties have been measured on both isothermally forged and extruded billets, as well as on specimens cut from actual parts. The temperature capability of the alloy is about 700 C for long-term applications and approximately 750 C for short-term use because of microstructural instability. Further improvements in creep and crack propagation properties, without significant reduction in tensile strength, are possible through appropriate thermomechanical processing, which results in a large controlled grain size. Spin pit tests on subscale disks have confirmed that the N18 alloy has a higher resistance than PM Astrology and is therefore an excellent alloy for modern turbine disk applications.

  11. Powder metallurgy: Solid and liquid phase sintering of copper

    Science.gov (United States)

    Sheldon, Rex; Weiser, Martin W.

    1993-01-01

    Basic powder metallurgy (P/M) principles and techniques are presented in this laboratory experiment. A copper based system is used since it is relatively easy to work with and is commercially important. In addition to standard solid state sintering, small quantities of low melting metals such as tin, zinc, lead, and aluminum can be added to demonstrate liquid phase sintering and alloy formation. The Taguchi Method of experimental design was used to study the effect of particle size, pressing force, sintering temperature, and sintering time. These parameters can be easily changed to incorporate liquid phase sintering effects and some guidelines for such substitutions are presented. The experiment is typically carried out over a period of three weeks.

  12. An application of powder metallurgy for the LHC

    CERN Document Server

    Sgobba, Stefano

    2004-01-01

    The cold mass of the 1232 superconducting dipole magnets of LHC, operating at 1.9 K, is enclosed by a shrinking cylinder and two end covers at its extremities. The covers are structural components that must retain high strength and toughness at cryogenic temperature. They are manufactured by Metso Oy /FI in AISI 316 LN steel by Powder Metallurgy (PM) and Hot Isostatic Pressing. PM represents an attractive near net shaping technique for these components of complex geometry for which dimension tolerances, dimensional stability, weldability are key issues for magnet fabrication, and mechanical properties, ductility and leak tightness have to be guaranteed during operation. The material of the covers and its welds have been fully characterized and mechanically tested down to 4.2 K at CERN. The fine grained structure, the absence of residual stresses, the full isotropy of mechanical properties associated to the low level of Prior Particle Boundaries oxides result in superior mechanical properties and high ductilit...

  13. New alloying systems for ferrous powder metallurgy precision parts

    Directory of Open Access Journals (Sweden)

    Danninger H.

    2008-01-01

    Full Text Available Traditionally, the common alloy elements for sintered steels have been Cu and Ni. With increasing requirements towards mechanical properties, and also as a consequence of soaring prices especially for these two metals, other alloy elements have also become more and more attractive for sintered steels, which make the steels however more tricky to process through PM. Here, the chances and risks of using in particular Cr and Mn alloy steels are discussed, considering the different alloying techniques viable in powder metallurgy, and it is shown that there are specific requirements in particular for sintering process. The critical importance of chemical reactions between the metal and the atmosphere is described, and it is shown that not only O2 and H2O but also H2 and even N2 can critically affect sintering and microstructural homogenization.

  14. Microwave Power Absorption in Materials for Ferrous Metallurgy

    Science.gov (United States)

    Peng, Zhiwei; Li, Zhizhong; Lin, Xiaolong; Yang, Mengshen; Hwang, Jiann-Yang; Zhang, Yuanbo; Li, Guanghui; Jiang, Tao

    2016-11-01

    The characteristics of microwave power absorption in materials for ferrous metallurgy, including iron oxides (Fe2O3, Fe3O4 and Fe0.925O) and bitumite, were explored by evaluating their dielectric loss (Q E) and/or magnetic loss (Q H) distributions in the 0.05-m-thick slabs of the corresponding materials exposed to 1.2-kW and 2.45-GHz microwave radiation at temperatures below 1100°C. It is revealed that the dielectric loss contributes primarily to the power absorption in Fe2O3, Fe0.925O and the bitumite at all of the examined temperatures. Their Q E values at room temperature and slab surface are 9.1311 × 103 W m-3, 23.7025 × 103 W m-3, and 49.5999 × 103 W m-3, respectively, showing that the materials have the following heating rate initially under microwave irradiation: bitumite > Fe0.925O > Fe2O3. Compared with the other materials, Fe3O4 has much stronger power absorption, primarily originated from its magnetic loss (e.g., Q H = 1.0615 × 106 W m-3, Q H/Q E = 2.4185 at 24°C and slab surface), below its Curie point, above which the magnetic susceptibility approaches to zero, thereby causing a very small Q H value at even the surface (Q H = 1.0416 × 105 W m-3 at 880°C). It is also demonstrated that inhomogeneous power distributions occur in all the slabs and become more pronounced with increasing temperature mainly due to rapid increase in permittivity. Characterizing power absorption in the oxides and the coal is expected to offer a strategic guide for improving use of microwave energy in ferrous metallurgy.

  15. Industrial Chemistry at Michigan Tech.

    Science.gov (United States)

    Bates, D. K.; Ponter, A. B.

    1985-01-01

    Discusses factors leading to the development of a four-year industrial chemistry program at Michigan Technological University and provides details of its structure. Includes brief descriptions of courses required in industrial chemistry but not in the traditional chemistry program and list of optional courses. (JN)

  16. Characterization of TiC-FeCrMn Cermets Produced by Powder Metallurgy Method

    Directory of Open Access Journals (Sweden)

    Märt Kolnes

    2015-09-01

    Full Text Available TiC-NiMo cermets combine relatively low density with high hardness. Because nickel is known as a toxin and allergen and allergy to nickel is a phenomenon which has assumed growing importance in recent years there has been a flurry of activity to find alternatives to the nickel binder in cermets. It is also the global research and technical development trend in the powder metallurgy cermets industry. In present research TiC-based cermets with FeCrMn binder system were fabricated. Three different sintering conditions were used (vacuum sintering, sinter/HIP and sintering under low Ar pressure. Because of high vapor pressure of manganese different sintering conditions and technologies were investigated to depress the Mn-loss during sintering. Chemical composition of TiC-FeCrMn cermets after different sintering conditions were analyzed by energy-dispersive X-ray spectroscopy (EDS and mechanical properties – hardness and fracture toughness were evaluated on the samples. Results of research showed that Ni-free TiC-based CrMn-steels bonded cermets compare unfavorably with cermets bonded with CrNi austenitic steels in terms of fracture toughness and corrosion resistance. Noticeable Mn-loss during vacuum sintering can be avoided when sintering under low Ar gas pressure.DOI: http://dx.doi.org/10.5755/j01.ms.21.3.7364

  17. Use of semantic technologies for the development of a dynamic trajectories generator in a Semantic Chemistry eLearning platform

    CERN Document Server

    Huber, Richard; Todor, Alexandru; Krebs, Sebastian; Heese, Ralf; Paschke, Adrian

    2010-01-01

    ChemgaPedia is a multimedia, webbased eLearning service platform that currently contains about 18.000 pages organized in 1.700 chapters covering the complete bachelor studies in chemistry and related topics of chemistry, pharmacy, and life sciences. The eLearning encyclopedia contains some 25.000 media objects and the eLearning platform provides services such as virtual and remote labs for experiments. With up to 350.000 users per month the platform is the most frequently used scientific educational service in the German spoken Internet. In this demo we show the benefit of mapping the static eLearning contents of ChemgaPedia to a Linked Data representation for Semantic Chemistry which allows for generating dynamic eLearning paths tailored to the semantic profiles of the users.

  18. Developments in physical chemistry and basic principles

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, H.Y. (Univ. of Utah, UT (US))

    1992-04-01

    The metallurgical industry faces challenges in the development and production of new products in response to rapidly changing technologies that demand materials with widely different properties and increasingly stringent quality control. Such materials include semiconductors, ultrahigh-purity metals, chemical-vapor-deposited metallic films, high-performance intermetallics, metallic superconductors, and metal-based composites. In view of this, the author propounded the establishment of value-addition metallurgy as a subdiscipline of extractive and process metallurgy. Such a subdiscipline would cover the principles and practice involved in the production of these value-added advanced materials based on metals. In this respect, this annual review article now includes a section covering papers concerned with these topics.

  19. Study on microstructure of Fe-Cr-C-Ni-B-Si coating formed by plasma jet surface metallurgy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The technical connotation of surface metallurgical technology by DC-Plasma-Jet is a kind of rapid, non-equilibrium metallurgical process which is similar to powder metallurgy. Accordingly the specialized equipment is developed all by ourselves, which is not subjected to limitation of solubility, melting point, density of constituents, therefore pre-alloy powders are not needed. The plasma surface metallurgical coating using Fe-Cr-C-Ni-B-Si mixed alloy powders has good wettability with substrate material. The metallurgical coating has apparent characteristics of rapid and layered crystallization from planar crystal-cell to dendritic transition zone at the interface, from dendritic crystal to equiaxed crystal in the midst, from equiaxed crystal to spike crystal on the surface. Its metastable microstructure is complex phase of supersaturated-γ(Fe,Ni) dendritic crystal solutioning great amount of alloy element and interdendritic eutectic structure (Cr, Fe)7(C,B)3 and γ(Fe,Ni).

  20. Indexation Rules for Metallurgy in PASCAL. Original Title: Regles d'Indexation de la Metallurgie'--Technical Note Issued by Informascience--January 1980. Translated by Marie Wallin.

    Science.gov (United States)

    Royal Inst. of Tech., Stockholm (Sweden). Library.

    The indexing rules presented are designed for use with a new French-German database on metallurgy being developed under an agreement by CNRS (Centre National de la Recherche Scientifique, Paris) and BAM (Bundesanstalt fur Materialprufung, Berlin). The new database, which will feature multilingual titles and index terms (French-German-English-) and…

  1. TRADITIONAL METALLURGY, NANOTECHNOLOGIES AND STRUCTURAL MATERIALS: A SORBY AWARD LECTURE

    Energy Technology Data Exchange (ETDEWEB)

    Louthan, M

    2007-07-17

    Traditional metallurgical processes are among the many ''old fashion'' practices that use nanoparticles to control the behavior of materials. Many of these practices were developed long before microscopy could resolve nanoscale features, yet the practitioners learned to manipulate and control microstructural elements that they could neither see nor identify. Furthermore, these early practitioners used that control to modify microstructures and develop desired material properties. Centuries old colored glass, ancient high strength steels and medieval organ pipes derived many of their desirable features through control of nanoparticles in their microstructures. Henry Sorby was among the first to recognize that the properties of rocks, minerals, metals and organic materials were controlled by microstructure. However, Mr. Sorby was accused of the folly of trying to study mountains with a microscope. Although he could not resolve nanoscale microstructural features, Mr. Sorby's observations revolutionized the study of materials. The importance of nanoscale microstructural elements should be emphasized, however, because the present foundation for structural materials was built by manipulating those features. That foundation currently supports several multibillion dollar industries but is not generally considered when the nanomaterials revolution is discussed. This lecture demonstrates that using nanotechnologies to control the behavior of metallic materials is almost as old as the practice of metallurgy and that many of the emergent nanomaterials technologists are walking along pathways previously paved by traditional metallurgists.

  2. [Possible health effects associated with Pre-Columbian metallurgy].

    Science.gov (United States)

    Idrovo, Alvaro Javier

    2005-09-01

    In the Old World, several researchers have indicated that adverse health effects were associated with exposure to arsenic, and that this influenced a change in the use of copper-arsenic alloys to others less toxic. This hypothesis was evaluated for three Pre-Columbian metallurgy traditions: Central Andes, Intermediate Area, and West Mexico. The metal artifacts from the Central Andes showed arsenic concentrations similar to those in the Old World (0.5%-1.0%). In the Intermediate Area the values were smallest; however, in West Mexico the arsenic content was very high (7%-25%). In Central Andes arsenical bronze was used initially, but copper-tin alloys when introduced were preferred and distributed throughout the Inca Empire. Osteological and artistic evidences of foot amputations among Moche individuals from Central Andes support the presence of "black foot disease" (a condition associated with arsenic poisoning) among Pre-Columbian populations. In conclusion, the adverse effects of arsenic have been observed in the New World, and that these effects promoted a change toward the use of less toxic alloys.

  3. Macromolecular metallurgy of binary mesocrystals via designed multiblock terpolymers.

    Science.gov (United States)

    Xie, Nan; Liu, Meijiao; Deng, Hanlin; Li, Weihua; Qiu, Feng; Shi, An-Chang

    2014-02-26

    Self-assembling block copolymers provide access to the fabrication of various ordered phases. In particular, the ordered spherical phases can be used to engineer soft mesocrystals with domain size at the 5-100 nm scales. Simple block copolymers, such as diblock copolymers, form a limited number of mesocrystals. However multiblock copolymers are capable to form more complex mesocrystals. We demonstrate that designed B1AB2CB3 multiblock terpolymers, in which the A- and C-blocks form spherical domains and the packing of these spheres can be controlled by changing the lengths of the middle and terminal B-blocks, self-assemble into various binary mesocrystals with space group symmetries of a large number of binary ionic crystals, including NaCl, CsCl, ZnS, α-BN, AlB2, CaF2, TiO2, ReO3, Li3Bi, Nb3Sn(A15), and α-Al2O3. This approach can be generalized to other terpolymers as well as to tetrapolymers to obtain ternary mesocrystals. Our study provides a new concept of macromolecular metallurgy for producing crystal phases in a mesoscale and thus makes multiblock copolymers a robust platform for the engineering of functional materials.

  4. Device for preparing combinatorial libraries in powder metallurgy.

    Science.gov (United States)

    Yang, Shoufeng; Evans, Julian R G

    2004-01-01

    This paper describes a powder-metering, -mixing, and -dispensing mechanism that can be used as a method for producing large numbers of samples for metallurgical evaluation or electrical or mechanical testing from multicomponent metal and cermet powder systems. It is designed to make use of the same commercial powders that are used in powder metallurgy and, therefore, to produce samples that are faithful to the microstructure of finished products. The particle assemblies produced by the device could be consolidated by die pressing, isostatic pressing, laser sintering, or direct melting. The powder metering valve provides both on/off and flow rate control of dry powders in open capillaries using acoustic vibration. The valve is simple and involves no relative movement, avoiding seizure with fine powders. An orchestra of such valves can be arranged on a building platform to prepare multicomponent combinatorial libraries. As with many combinatorial devices, identification and evaluation of sources of mixing error as a function of sample size is mandatory. Such an analysis is presented.

  5. Welding metallurgy of nickel alloys in gas turbine components

    Energy Technology Data Exchange (ETDEWEB)

    Lingenfelter, A. C., LLNL

    1997-05-21

    Materials for gas turbine engines are required to meet a wide range of temperature and stress application requirements. These alloys exhibit a combination of creep resistance, creep rupture strength, yield and tensile strength over a wide temperature range, resistance to environmental attack (including oxidation, nitridation, sulphidation and carburization), fatigue and thermal fatigue resistance, metallurgical stability and useful thermal expansion characteristics. These properties are exhibited by a series of solid-solution-strengthened and precipitation-hardened nickel, iron and cobalt alloys. The properties needed to meet the turbine engine requirements have been achieved by specific alloy additions, by heat treatment and by thermal mechanical processing. A thorough understanding of the metallurgy and metallurgical processing of these materials is imperative in order to successfully fusion weld them. This same basic understanding is required for repair of a component with the added dimension of the potential effects of thermal cycling and environmental exposure the component will have endured in service. This article will explore the potential problems in joining and repair welding these materials.

  6. [Atmospheric emission of PCDD/Fs from secondary aluminum metallurgy industry in the southwest area, China].

    Science.gov (United States)

    Lu, Yi; Zhang, Xiao-Ling; Guo, Zhi-Shun; Jian, Chuan; Zhu, Ming-Ji; Deng, Li; Sun, Jing; Zhang, Qin

    2014-01-01

    Five secondary aluminum metallurgy enterprises in the southwest area of China were measured for emissions of PCDD/Fs. The results indicated that the emission levels of PCDD/Fs (as TEQ) were 0.015-0.16 ng x m(-3), and the average was 0.093 ng x m(-3) from secondary aluminum metallurgy enterprises. Emission factors of PCDD/Fs (as TEQ) from the five secondary aluminum metallurgy enterprises varied between 0.041 and 4.68 microg x t(-1) aluminum, and the average was 2.01 microg x t(-1) aluminum; among them, PCDD/Fs emission factors from the crucible smelting furnace was the highest. Congener distribution of PCDD/F in stack gas from the five secondary aluminum metallurgies was very different from each other. Moreover, the R(PCDF/PCDD) was the lowest in the enterprise which was installed only with bag filters; the R(PCDF/PCDD) were 3.8-12.6 (the average, 7.7) in the others which were installed with water scrubbers. The results above indicated that the mechanism of PCDD/Fs formation was related to the types of exhaust gas treatment device. The results of this study can provide technical support for the formulation of PCDD/Fs emission standards and the best available techniques in the secondary aluminum metallurgy industry.

  7. Quelccaya Ice Core Evidence of Widespread Atmospheric Pollution from Colonial Metallurgy after the Spanish Conquest of South America (1532 AD)

    Science.gov (United States)

    Gabrielli, P.; Uglietti, C.; Cooke, C. A.; Thompson, L. G.

    2014-12-01

    A few ice core records recovered from remote arctic regions suggest a widespread impact of toxic trace elements (Pb, Cu, Sb, As and Bi) to the North Hemisphere atmosphere prior to the onset of the Industrial Revolution (1780s-1830s). In the Southern Hemisphere, evidence for preindustrial trace element emissions are, to date, limited to sediment cores recovered from lakes located within the immediate airshed of major metallurgical centers of South America. Thus it remains unresolved whether they could have had a larger scale impact. Here, we present an annually resolved ice core record of anthropogenic trace element deposition from the remote drilling site of the Quelccaya Ice Cap (Peru) that spans 793-1989 AD. During the pre-Inca period (i.e., prior to ~1450 AD) the deposition of trace elements was dominated by the fallout of aeolian dust from the deglaciated margins of the ice cap and of ash from occasional volcanic eruptions. In contrast, the ice core record indicates a clear anthropogenic signal emerging after the onset of large scale colonial mining and metallurgy (1532-1820 AD), ~300 years prior to the Industrial Revolution during the last part of the Little Ice Age. This shift was coincidental with a major technological transition for silver extraction (1572 AD), from lead-based smelting to mercury amalgamation, that initiated a major increase in ore mining and milling that likely resulted in an increase of metallic dust emissions. While atmospheric trace element deposition resulting from colonial metallurgy was certainly much larger than during the pre-Colonial period, trace element fallout during the Colonial era was still several factors lower than during the 20th century, when the construction of the trans-Andean railway and highways promoted a widespread societal and industrial development of South America.

  8. Introduction to powder metallurgy processes for titanium manufacturing; Introduccion al procesado pulvimetalurgico del titanio

    Energy Technology Data Exchange (ETDEWEB)

    Esteban, P. G.; Bolzoni, L.; Ruiz-Navas, E. M.; Gordo, E.

    2011-07-01

    The development of new extraction processes to produce titanium in powder form leads Powder Metallurgy to an advantage position among the manufacturing processes for titanium. The cost reduction of base material, coupled with the economy of the powder metallurgy processes, give titanium industry the chance to diversify its products, which could lead to production volumes able to stabilise the price of the metal. This work reviews some of the Powder Metallurgy techniques for the manufacturing of titanium parts, and describes the two typical approaches for titanium manufacturing: Blending Elemental and Prealloyed Powders. Among others, conventional pressing and sintering are described, which are compared with cold and hot isostatic pressing techniques. Real and potential applications are described. (Author) 71 refs.

  9. Corrosion inhibition of powder metallurgy Mg by fluoride treatments.

    Science.gov (United States)

    Pereda, M D; Alonso, C; Burgos-Asperilla, L; del Valle, J A; Ruano, O A; Perez, P; Fernández Lorenzo de Mele, M A

    2010-05-01

    Pure Mg has been proposed as a potential degradable biomaterial to avoid both the disadvantages of non-degradable internal fixation implants and the use of alloying elements that may be toxic. However, it shows excessively high corrosion rate and insufficient yield strength. The effects of reinforcing Mg by a powder metallurgy (PM) route and the application of biocompatible corrosion inhibitors (immersion in 0.1 and 1M KF solution treatments, 0.1M FST and 1M FST, respectively) were analyzed in order to improve Mg mechanical and corrosion resistance, respectively. Open circuit potential measurements, polarization techniques (PT), scanning electrochemical microscopy (SECM) and electrochemical impedance spectroscopy (EIS) were performed to evaluate its corrosion behavior. SECM showed that the local current of attacked areas decreased during the F(-) treatments. The corrosion inhibitory action of 0.1M FST and 1M FST in phosphate buffered solution was assessed by PT and EIS. Under the experimental conditions assayed, 0.1M FST revealed better performance. X-ray photoelectron spectroscopy, energy dispersive X-ray and X-ray diffraction analyses of Mg(PM) with 0.1M FST showed the presence of KMgF(3) crystals on the surface while a MgF(2) film was detected for 1M FST. After fluoride inhibition treatments, promising results were observed for Mg(PM) as degradable metallic biomaterial due to its higher yield strength and lower initial corrosion rate than untreated Mg, as well as a progressive loss of the protective characteristics of the F(-)-containing film which ensures the gradual degradation process.

  10. Modernization of the Ural Metallurgy during the Great Patriotic War (1941–1945

    Directory of Open Access Journals (Sweden)

    Vladimir V. Zaparii

    2013-09-01

    Full Text Available The article characterizes the Ural industry modernization in war footing, shows the significance of evacuation of enterprises from the Western areas of the country to the region, reveals their role in the formation of a new metallurgical center of modern metallurgy in terms of human resources and manufacture. Innovations in metallurgy, the role of human factor in solving industrial restructuring problem are examined. Forms and methods of science use for the industrial modernization are considered. Solving of human resources problem is shown. The author touches upon the problem of metallurgical sector management in wartime. The role of people’s heroism in this difficult period of Russian history is discussed.

  11. [Analysis of changes in characteristics of arterial hypertension occupational risk in workers of nonferrous metallurgy].

    Science.gov (United States)

    Vlasova, E M; Shliapnikov, D M; Lebedeva, T M

    2015-01-01

    The article covers changes in occupational cardiovascular risk for workers of nonferrous,metallurgy. Findings are that exposure to noise up to 94 dB with length of service increases possible atherosclerosis and metabolic syndrome. With 5 years of service, risk of the predicted conditions increases by 40.5%. When occupational exposure lasts over 5 years, risk of arterial hypertension increases. A group of workers without exposure to occupational factors appeared to have no connection between length of service and metabolic syndrome and arterial hypertension. Risk evolution modelling proved that risk of functional disorders in nonferrous metallurgy workers becomes unacceptable after 5 years of service (cardiovascular disorders are critical).

  12. Pesticides: a reflective socio-environmental proposal in chemistry teaching under a science, technology and society (sts perspective

    Directory of Open Access Journals (Sweden)

    Andréia Cristina Cunha Buffolo

    2015-03-01

    Full Text Available In this article we discuss the contribution of a didactic sequence with the theme “pesticides” in the articulation of chemistry knowledge and socio-environmental questions with public high school students. The above-mentioned sequence, prepared according to the presuppositions of an STS orientation and three pedagogical moments, was developed with twenty-two 2nd year students. The students that participated in the research, in addition to responding to a diagnostic questionnaire about the theme, were involved, during the pedagogical intervention, in group activities, reading and discussion of texts, problem resolution, research with local farmers, preparation of seminars and production of texts. All the moments of the intervention, which had the participation (verbal or nonverbal of the students, were recorded using a voice recorder and a field journal. The results revealed that the development of the didactic sequence widened the vision of the students as regards the social and environmental implications provoked by the inadequate use of pesticides, in addition to reflections and greater understanding about the theme, showing the importance of introducing socio-environmental questions in chemistry teaching with an STS perspective.

  13. Divergence in male and female manipulative behaviors with the intensification of metallurgy in Central Europe.

    Science.gov (United States)

    Macintosh, Alison A; Pinhasi, Ron; Stock, Jay T

    2014-01-01

    Humeral morphology has been shown to reflect, in part, habitual manipulative behaviors in humans. Among Central European agricultural populations, long-term social change, increasing task specialization, and technological innovation all had the potential to impact patterns of habitual activity and upper limb asymmetry. However, systematic temporal change in the skeletal morphology of agricultural populations in this region has not been well-characterized. This study investigates diachronic patterns in humeral biomechanical properties and lengths among 174 adult Central European agriculturalists through the first ∼ 5400 years of farming in the region. Greater asymmetry in biomechanical properties was expected to accompany the introduction of metallurgy, particularly in males, while upper limb loading patterns were expected to be more similar between the Bronze and Iron Ages. Results revealed a divergence in the lateralization of upper limb biomechanical properties by sex between the Early/Middle Neolithic and Early/Middle Bronze Age. Neolithic females had significantly more variable properties than males in both humeri, while Bronze Age female properties became homogeneous and very symmetrical relative to the right-biased lateralization of contemporaneous males. The Bronze Age to Iron Age transition was associated with morphological change among females, with a significant increase in right-biased asymmetry and a concomitant reduction in sexual dimorphism. Relative to biomechanical properties, humeral length variation and asymmetry were low though some significant sexual dimorphism and temporal change was found. It was among females that the lateralization of humeral biomechanical properties, and variation within them, changed most profoundly through time. This suggests that the introduction of the ard and plow, metallurgical innovation, task specialization, and socioeconomic change through ∼ 5400 years of agriculture impacted upper limb loading in Central

  14. 计算机在化学教学中的应用%The Application of Computer Technology in High School Chemistry Teaching

    Institute of Scientific and Technical Information of China (English)

    秦慧娟

    2013-01-01

    Computer-assisted teaching is the primary tool of high school multi-media teachings. Multi-media animation can stim-ulate students' interests in learning chemistry. Using multimedia 3D production technology, microscopic chemistry world can be displayed as observable macroscopic world with the aid of graph-ic images. Computer-assisted teaching is an effective way to break through the teaching difficulties and further improves the efficiency of classroom teaching.%  计算机辅助教学,是中学多媒体教学应用的主要形式。在化学教学中,运用多媒体动态模拟功能,可激发学生的学习兴趣;运用多媒体三维制作技术,通过图形、图像,把微观世界变成宏观世界,可突破教学难点,进一步提高课堂教学效率。

  15. Chemistry Notes

    Science.gov (United States)

    School Science Review, 1976

    1976-01-01

    Described are eight chemistry experiments and demonstrations applicable to introductory chemistry courses. Activities include: measure of lattice enthalpy, Le Chatelier's principle, decarboxylation of soap, use of pocket calculators in pH measurement, and making nylon. (SL)

  16. Heterocyclic chemistry

    OpenAIRE

    Hemming, Karl

    2011-01-01

    Recent progress in the synthesis of heterocyclic compounds is presented\\ud 2010 offered highlights in pericyclic chemistry, particularly 1,3-dipolar cycloaddition chemistry, asymmetric synthesis, gold catalysis, organocatalysis, hydroamination, C–H activation and multicomponent reactions.

  17. Chemistry Dashboard

    Science.gov (United States)

    The Chemistry Dashboard is part of a suite of dashboards developed by EPA to help evaluate the safety of chemicals. The Chemistry Dashboard provides access to a variety of information on over 700,000 chemicals currently in use.

  18. Biophysical chemistry.

    Science.gov (United States)

    Häussinger, Daniel; Pfohl, Thomas

    2010-01-01

    Biophysical chemistry at the Department of Chemistry, University of Basel, covers the NMR analysis of protein-protein interaction using paramagnetic tags and sophisticated microscopy techniques investigating the dynamics of biological matter.

  19. Colour Chemistry

    Science.gov (United States)

    Griffiths, J.; Rattee, I. D.

    1973-01-01

    Discusses the course offerings in pure color chemistry at two universities and the three main aspects of study: dyestuff chemistry, color measurement, and color application. Indicates that there exists a constant challenge to ingenuity in the subject discipline. (CC)

  20. Elevated temperature crack growth in advanced powder metallurgy aluminum alloys

    Science.gov (United States)

    Porr, William C., Jr.; Gangloff, Richard P.

    1990-01-01

    Rapidly solidified Al-Fe-V-Si powder metallurgy alloy FVS0812 is among the most promising of the elevated temperature aluminum alloys developed in recent years. The ultra fine grain size and high volume fraction of thermally stable dispersoids enable the alloy to maintain tensile properties at elevated temperatures. In contrast, this alloy displays complex and potentially deleterious damage tolerant and time dependent fracture behavior that varies with temperature. J-Integral fracture mechanics were used to determine fracture toughness (K sub IC) and crack growth resistance (tearing modulus, T) of extruded FVS0812 as a function of temperature. The alloy exhibits high fracture properties at room temperature when tested in the LT orientation, due to extensive delamination of prior ribbon particle boundaries perpendicular to the crack front. Delamination results in a loss of through thickness constraint along the crack front, raising the critical stress intensity necessary for precrack initiation. The fracture toughness and tensile ductility of this alloy decrease with increasing temperature, with minima observed at 200 C. This behavior results from minima in the intrinsic toughness of the material, due to dynamic strain aging, and in the extent of prior particle boundary delaminations. At 200 C FVS0812 fails at K levels that are insufficient to cause through thickness delamination. As temperature increases beyond the minimum, strain aging is reduced and delamination returns. For the TL orientation, K (sub IC) decreased and T increased slightly with increasing temperature from 25 to 316 C. Fracture in the TL orientation is governed by prior particle boundary toughness; increased strain localization at these boundaries may result in lower toughness with increasing temperature. Preliminary results demonstrate a complex effect of loading rate on K (sub IC) and T at 175 C, and indicate that the combined effects of time dependent deformation, environment, and strain aging

  1. Testing of electroformed deposited iridium/powder metallurgy rhenium rockets

    Science.gov (United States)

    Reed, Brian D.; Dickerson, Robert

    1996-01-01

    High-temperature, oxidation-resistant chamber materials offer the thermal margin for high performance and extended lifetimes for radiation-cooled rockets. Rhenium (Re) coated with iridium (Ir) allow hours of operation at 2200 C on Earth-storable propellants. One process for manufacturing Ir/Re rocket chambers is the fabrication of Re substrates by powder metallurgy (PM) and the application of Ir coatings by using electroformed deposition (ED). ED Ir coatings, however, have been found to be porous and poorly adherent. The integrity of ED Ir coatings could be improved by densification after the electroforming process. This report summarizes the testing of two 22-N, ED Ir/PM Re rocket chambers that were subjected to post-deposition treatments in an effort to densify the Ir coating. One chamber was vacuum annealed, while the other chamber was subjected to hot isostatic pressure (HIP). The chambers were tested on gaseous oxygen/gaseous hydrogen propellants, at mixture ratios that simulated the oxidizing environments of Earth-storable propellants. ne annealed ED Ir/PM Re chamber was tested for a total of 24 firings and 4.58 hr at a mixture ratio of 4.2. After only 9 firings, the annealed ED Ir coating began to blister and spall upstream of the throat. The blistering and spalling were similar to what had been experienced with unannealed, as-deposited ED Ir coatings. The HIP ED Ir/PM Re chamber was tested for a total of 91 firings and 11.45 hr at mixture ratios of 3.2 and 4.2. The HIP ED Ir coating remained adherent to the Re substrate throughout testing; there were no visible signs of coating degradation. Metallography revealed, however, thinning of the HIP Ir coating and occasional pores in the Re layer upstream of the throat. Pinholes in the Ir coating may have provided a path for oxidation of the Re substrate at these locations. The HIP ED Ir coating proved to be more effective than vacuum annealed and as-deposited ED Ir. Further densification is still required to

  2. Investigation of the Environmental Durability of a Powder Metallurgy Material

    Science.gov (United States)

    Ward, LaNita D.

    2004-01-01

    PM304 is a NASA-developed composite powder metallurgy material that is being developed for high temperature applications such as bushings in high temperature industrial furnace conveyor systems. My goal this summer was to analyze and evaluate the effects that heat exposure had on the PM304 material at 500 C and 650 C. The material is composed of Ni-Cr, Ag, Cr2O3, and eutectic BaF2-CaF2. PM304 is designed to eliminate the need for oil based lubricants in high temperature applications, while reducing friction and wear. However, further investigation was needed to thoroughly examine the properties of PM304. The effects of heat exposure on PM304 bushings were investigated. This investigation was necessary due to the high temperatures that the material would be exposed to in a typical application. Each bushing was cut into eight sections. The specimens were heated to 500 C or 650 C for time intervals from 1 hr to 5,000 hrs. Control specimens were kept at room temperature. Weight and thickness measurements were taken before and after the bushing sections were exposed to heat. Then the heat treated specimens were mounted and polished side by side with the control specimens. This enabled optical examination of the material's microstructure using a metallograph. The specimens were also examined with a scanning electron microscope (SEM). The microstructures were compared to observe the effects of the heat exposure. Chemical analysis was done to investigate the interactions between Ni-Cr and BaF2-CaF2 and between Cr2O3 and BaF2-CaF2 at high temperature. To observe this, the two compounds that were being analyzed were mixed in a crucible in varied weight percentages and heated to 1100 C in a furnace for approximately two hours. Then the product was allowed to cool and was then analyzed by X-ray diffraction. Interpretation of the results is in progress.

  3. Combinatorial chemistry

    DEFF Research Database (Denmark)

    Nielsen, John

    1994-01-01

    An overview of combinatorial chemistry is presented. Combinatorial chemistry, sometimes referred to as `irrational drug design,' involves the generation of molecular diversity. The resulting chemical library is then screened for biologically active compounds.......An overview of combinatorial chemistry is presented. Combinatorial chemistry, sometimes referred to as `irrational drug design,' involves the generation of molecular diversity. The resulting chemical library is then screened for biologically active compounds....

  4. Combinatorial chemistry

    DEFF Research Database (Denmark)

    Nielsen, John

    1994-01-01

    An overview of combinatorial chemistry is presented. Combinatorial chemistry, sometimes referred to as `irrational drug design,' involves the generation of molecular diversity. The resulting chemical library is then screened for biologically active compounds.......An overview of combinatorial chemistry is presented. Combinatorial chemistry, sometimes referred to as `irrational drug design,' involves the generation of molecular diversity. The resulting chemical library is then screened for biologically active compounds....

  5. Positronium chemistry

    CERN Document Server

    Green, James

    1964-01-01

    Positronium Chemistry focuses on the methodologies, reactions, processes, and transformations involved in positronium chemistry. The publication first offers information on positrons and positronium and experimental methods, including mesonic atoms, angular correlation measurements, annihilation spectra, and statistical errors in delayed coincidence measurements. The text then ponders on positrons in gases and solids. The manuscript takes a look at the theoretical chemistry of positronium and positronium chemistry in gases. Topics include quenching, annihilation spectrum, delayed coincidence

  6. The Application of Thermal Plasma to Extraction Metallurgy and Related Fields

    Science.gov (United States)

    Akashi, K.

    1980-01-01

    Various applications of thermal plasma to extraction metallurgy and related fields are surveyed, chiefly on the basis of documents published during the past two or three years. Applications to melting and smelting, to thermal decomposition, to reduction, to manufacturing of inorganic compounds, and to other fields are considered.

  7. Ice-core evidence of earliest extensive copper metallurgy in the Andes 2700 years ago

    Science.gov (United States)

    Eichler, A.; Gramlich, G.; Kellerhals, T.; Tobler, L.; Rehren, Th.; Schwikowski, M.

    2017-01-01

    The importance of metallurgy for social and economic development is indisputable. Although copper (Cu) was essential for the wealth of pre- and post-colonial societies in the Andes, the onset of extensive Cu metallurgy in South America is still debated. Comprehensive archaeological findings point to first sophisticated Cu metallurgy during the Moche culture ~200–800 AD, whereas peat-bog records from southern South America suggest earliest pollution potentially from Cu smelting as far back as ~2000 BC. Here we present a 6500-years Cu emission history for the Andean Altiplano, based on ice-core records from Illimani glacier in Bolivia, providing the first complete history of large-scale Cu smelting activities in South America. We find earliest anthropogenic Cu pollution during the Early Horizon period ~700–50 BC, and attribute the onset of intensified Cu smelting in South America to the activities of the central Andean Chiripa and Chavin cultures ~2700 years ago. This study provides for the first time substantial evidence for extensive Cu metallurgy already during these early cultures. PMID:28139760

  8. [Concomitant influence of occupational and social risk factors on health of workers engaged into powder metallurgy].

    Science.gov (United States)

    Shur, P Z; Zaĭtseva, N V; Kostarev, V G; Lebedeva-Nesevria, N A; Shliapnikov, D M

    2012-01-01

    Results of health risk evaluation in workers engaged into powder metallurgy, using complex of hygienic, medical, epidemiologic and sociologic studies, enable to define priority occupational and social risk factors, to assess degree of their influence on the workers' health and to identify occupationally induced diseases.

  9. Power metallurgy approaches to high temperature components for gas turbine engines

    Science.gov (United States)

    Probst, H. B.

    1974-01-01

    Work conducted by NASA and NASA contractors on prealloyed superalloy powders and materials strengthened by oxide dispersion is reviewed. Fabrication, tensile strength, superplasticity, grain growth control, stress rupture life, and grain-size and dispersion-level effects are covered. Distinct strength advantages of powder metallurgy superalloys over conventional wrought alloys are noted.

  10. Solvent Extraction of Copper: An Extractive Metallurgy Exercise for Undergraduate Teaching Laboratories

    Science.gov (United States)

    Smellie, Iain A.; Forgan, Ross S.; Brodie, Claire; Gavine, Jack S.; Harris, Leanne; Houston, Daniel; Hoyland, Andrew D.; McCaughan, Rory P.; Miller, Andrew J.; Wilson, Liam; Woodhall, Fiona M.

    2016-01-01

    A multidisciplinary experiment for advanced undergraduate students has been developed in the context of extractive metallurgy. The experiment serves as a model of an important modern industrial process that combines aspects of organic/inorganic synthesis and analysis. Students are tasked to prepare a salicylaldoxime ligand and samples of the…

  11. Powder metallurgy approaches to high temperature components for gas turbine engines

    Science.gov (United States)

    Probst, H. B.

    1974-01-01

    Research is reported for the tensile strength, ductility, and heat performance characterisitics of powder metallurgy (p/m) superalloys. Oxide dispersion strengthened alloys were also evaluated for their strength during thermal processing. The mechanical attributes evident in both p/m supperalloys and dispersion strengthened alloys are discussed in terms of research into their possible combination.

  12. Ice-core evidence of earliest extensive copper metallurgy in the Andes 2700 years ago

    Science.gov (United States)

    Eichler, A.; Gramlich, G.; Kellerhals, T.; Tobler, L.; Rehren, Th.; Schwikowski, M.

    2017-01-01

    The importance of metallurgy for social and economic development is indisputable. Although copper (Cu) was essential for the wealth of pre- and post-colonial societies in the Andes, the onset of extensive Cu metallurgy in South America is still debated. Comprehensive archaeological findings point to first sophisticated Cu metallurgy during the Moche culture ~200-800 AD, whereas peat-bog records from southern South America suggest earliest pollution potentially from Cu smelting as far back as ~2000 BC. Here we present a 6500-years Cu emission history for the Andean Altiplano, based on ice-core records from Illimani glacier in Bolivia, providing the first complete history of large-scale Cu smelting activities in South America. We find earliest anthropogenic Cu pollution during the Early Horizon period ~700-50 BC, and attribute the onset of intensified Cu smelting in South America to the activities of the central Andean Chiripa and Chavin cultures ~2700 years ago. This study provides for the first time substantial evidence for extensive Cu metallurgy already during these early cultures.

  13. Forensic chemistry.

    Science.gov (United States)

    Bell, Suzanne

    2009-01-01

    Forensic chemistry is unique among chemical sciences in that its research, practice, and presentation must meet the needs of both the scientific and the legal communities. As such, forensic chemistry research is applied and derivative by nature and design, and it emphasizes metrology (the science of measurement) and validation. Forensic chemistry has moved away from its analytical roots and is incorporating a broader spectrum of chemical sciences. Existing forensic practices are being revisited as the purview of forensic chemistry extends outward from drug analysis and toxicology into such diverse areas as combustion chemistry, materials science, and pattern evidence.

  14. Catalysis and sustainable (green) chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Centi, Gabriele; Perathoner, Siglinda [Dipartimento di Chimica Industriale ed Ingegneria dei Materiali, University of Messina, Salita Sperone 31, 98166 Messina (Italy)

    2003-01-15

    Catalysis is a key technology to achieve the objectives of sustainable (green) chemistry. After introducing the concepts of sustainable (green) chemistry and a brief assessment of new sustainable chemical technologies, the relationship between catalysis and sustainable (green) chemistry is discussed and illustrated via an analysis of some selected and relevant examples. Emphasis is also given to the concept of catalytic technologies for scaling-down chemical processes, in order to develop sustainable production processes which reduce the impact on the environment to an acceptable level that allows self-depuration processes of the living environment.

  15. High field performance of superconducting magnets using powder metallurgy processed Cu-Nb-Sn and Nb-Al

    Energy Technology Data Exchange (ETDEWEB)

    Zaleski, A.J.; Foner, S.

    1984-06-01

    Small superconducting magnets were fabricated with powder metallurgy processed Nb-Al wire and with powder metallurgy processed multistrand Cu-Nb--Sn wire with 19 tin cores. Tests in a background field of up to 15 T showed that short sample characteristics were achieved for three coils. Upper limits of resistivity were established for both powder metallurgy processed wires. The reacted wires in the magnets gave upper limits of resistivity at 10 T of less than 1.4 x 10/sup -14/ ..cap omega.. cm for the Nb/sub 3/Sn wire, and less than 9 x 10/sup -13/ ..cap omega.. cm for the Nb-Al wire.

  16. The Effect of Forging Variables on the Supersolvus Heat-Treatment Response of Powder-Metallurgy Nickel-Base Superalloys

    Science.gov (United States)

    2014-12-01

    AFRL-RX-WP-JA-2015-0160 THE EFFECT OF FORGING VARIABLES ON THE SUPERSOLVUS HEAT-TREATMENT RESPONSE OF POWDER-METALLURGY NICKEL -BASE SUPERALLOYS...POWDER-METALLURGY NICKEL - BASE SUPERALLOYS (POSTPRINT) 5a. CONTRACT NUMBER In-house 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62102F 6. AUTHOR...of Powder-Metallurgy Nickel -Base Superalloys S.L. SEMIATIN, J.M. SHANK, A.R. SHIVELEY, W.M. SAURBER, E.F. GAUSSA, and A.L. PILCHAK The effect of

  17. Perceptions of the Effects of Clicker Technology on Student Learning and Engagement: A Study of Freshmen Chemistry Students

    Science.gov (United States)

    Terrion, Jenepher Lennox; Aceti, Victoria

    2012-01-01

    While technology--in the form of laptops and cellphones--may be the cause of much of the distraction in university and college classrooms, some, including the personal or classroom response system (PRS/CRS) or clicker, also present pedagogical opportunities to enhance student engagement. The current study explored the reactions of students to…

  18. An impression on current developments in the technology, chemistry, and biological activities of ginger (Zingiber officinale Roscoe).

    Science.gov (United States)

    Kubra, I Rahath; Rao, L Jagan Mohan

    2012-01-01

    Ginger rhizome (Zingiber officinale Roscoe) is widely cultivated as a spice for its aromatic and pungent components. The essential oil and oleoresins from ginger are valuable products responsible for the characteristic flavor and pungency. Both are used in several food products such as soft beverages and also in many types of pharmaceutical formulations. More than 100 compounds have been reported from ginger, some of which are isolated and characterized, others are tentatively identified by GC-MS and / or LC-MS. [6]-Gingerol, the major gingerol in ginger rhizomes, has been found to possess many interesting pharmacological and physiological activities, such as anti-inflammatory, analgesic, and cardiotonic effects. Ginger is considered as "generally recognized as safe" (GRAS) by Food and Drug Administration (FDA), USA. Due to all these properties, ginger has gained considerable attention in developed countries in recent years, especially for its use in the treatment of inflammatory conditions. The present review is a persuasive presentation of the current information on processing, chemistry, biological activities, and medicinal uses of ginger. Further studies are required for the validation of the beneficial uses. Formulation for novel products and new usages may emerge in the years to come, based on the revealed results of various studies.

  19. Podcasts in the Chemistry Teaching

    Directory of Open Access Journals (Sweden)

    Bruno Silva Leite

    2016-12-01

    Full Text Available Information and Communication Technologies (ICT provide facilities in teaching through education. There are many new tools and methodologies that use ICT as a knowledge-building support, but that are not always related to pedagogical practice. The Podcast is an important technology that can be used in the classroom. Using this tool, it can make the most interactive chemistry class, fleeing the classroom routine. However, it is necessary to point out that the podcast is just one feature that should be incorporated into education and not a substitute. This paper describes the development of Chemistry Podcasts by teachers and chemistry students in three disciplines in 2015. This study took place over a one-year period in a public University, in Pernambuco, Brazil. In the discipline of "Computer applied to the teaching of chemistry" participated 21 Chemistry teachers. In the disciplines of "Information and Communication Technologies in the teaching of chemistry" and "Informatics, Chemistry and Education" was composed of 54 undergraduate students in chemistry. Twelve podcasts were elaborated by students and five by teachers in this paper we present only nine. The results showed the contribution of podcasts produced by teachers and students in teaching and learning process chemistry. DOI: http://dx.doi.org/10.17807/orbital.v0i0.898

  20. Thermal-hydraulics, physical chemistry, and technology at nuclear power stations equipped with fast-neutron sodium-cooled reactors

    Science.gov (United States)

    Alekseev, V. V.; Efanov, A. D.; Kozlov, F. A.; Sorokin, A. P.

    2007-12-01

    Main results of investigations aimed at developing a verified system of computer codes that take into account the interrelation among nuclear-physical, thermal-hydraulic, physicochemical, thermal-mechanical, mass-transfer, and technological processes in nuclear power installations and at substantiating the models used as the core of these codes are presented together with the results of tests carried out to obtain data for verifying the codes.

  1. From organic chemistry to fat and oil chemistry*

    OpenAIRE

    Deffense Etienne

    2009-01-01

    With his work on animal fat and identification of fatty acids, Chevreul was a pioneer in organic chemistry. As Chevreul, I had a passion for organic chemistry too. It was then, an honour and a pleasure to present in 2008 at EFL in Athens this presentation entitled “From organic chemistry to fat and oil chemistry” because my background in organic chemistry helped me all along my professional career to understand and implement new developments related to oil and fat technology and processing. A...

  2. Organic chemistry

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-08-15

    This book with sixteen chapter explains organic chemistry on linkage isomerism such as alkane, cycloalkane, alkene, aromatic compounds, stereo selective isomerization, aromatic compounds, stereo selective isomerization, organic compounds, stereo selective isomerization, organic halogen compound, alcohol, ether, aldehyde and ketone, carboxylic acid, dicarboxylic acid, fat and detergent, amino, carbohydrate, amino acid and protein, nucleotide and nucleic acid and spectroscopy, a polymer and medical chemistry. Each chapter has introduction structure and characteristic and using of organic chemistry.

  3. Computational chemistry

    OpenAIRE

    2000-01-01

    Computational chemistry has come of age. With significant strides in computer hardware and software over the last few decades, computational chemistry has achieved full partnership with theory and experiment as a tool for understanding and predicting the behavior of a broad range of chemical, physical, and biological phenomena. The Nobel Prize award to John Pople and Walter Kohn in 1998 highlighted the importance of these advances in computational chemistry. With massively parallel computers ...

  4. Nobel Prize in Chemistry

    Science.gov (United States)

    2000-01-01

    The Royal Swedish Academy has awarded the 1999 Nobel Prize in Chemistry to Ahmed H. Zewail (California Institute of Technology, Pasadena, CA) "for his studies of the transition states of chemical reactions using femtosecond spectroscopy". Zewail's work has taken the study of the rates and mechanisms of chemical reactions to the ultimate degree of detail - the time scale of bond making and bond breaking.

  5. [Characteristics of working conditions at metallurgy-related plants].

    Science.gov (United States)

    Egorova, A M

    2008-01-01

    Working conditions at more versus less advanced technology steel plants of the Volgograd Region are analyzed. The working conditions at the less advanced technology plants are referred to as a very high occupational risk. It is necessary to work out measures to lower the poor impact of microclimate, dust, noise, to improve illumination, and to regulate labor at steel plants.

  6. Hallmarks of mechanochemistry: from nanoparticles to technology.

    Science.gov (United States)

    Baláž, Peter; Achimovičová, Marcela; Baláž, Matej; Billik, Peter; Cherkezova-Zheleva, Zara; Criado, José Manuel; Delogu, Francesco; Dutková, Erika; Gaffet, Eric; Gotor, Francisco José; Kumar, Rakesh; Mitov, Ivan; Rojac, Tadej; Senna, Mamoru; Streletskii, Andrey; Wieczorek-Ciurowa, Krystyna

    2013-09-21

    The aim of this review article on recent developments of mechanochemistry (nowadays established as a part of chemistry) is to provide a comprehensive overview of advances achieved in the field of atomistic processes, phase transformations, simple and multicomponent nanosystems and peculiarities of mechanochemical reactions. Industrial aspects with successful penetration into fields like materials engineering, heterogeneous catalysis and extractive metallurgy are also reviewed. The hallmarks of mechanochemistry include influencing reactivity of solids by the presence of solid-state defects, interphases and relaxation phenomena, enabling processes to take place under non-equilibrium conditions, creating a well-crystallized core of nanoparticles with disordered near-surface shell regions and performing simple dry time-convenient one-step syntheses. Underlying these hallmarks are technological consequences like preparing new nanomaterials with the desired properties or producing these materials in a reproducible way with high yield and under simple and easy operating conditions. The last but not least hallmark is enabling work under environmentally friendly and essentially waste-free conditions (822 references).

  7. Thermogravimetric control of intermediate compounds in uranium metallurgy; Control termogravimetrico de productos intermedios de la metalurgia del uranio

    Energy Technology Data Exchange (ETDEWEB)

    Gasco Sanchez, L.; Fernandez Cellini, R.

    1959-07-01

    The thermal decomposition of some intermediate compounds in the metallurgy of the uranium as uranium peroxide, ammonium uranate, uranium and ammonium penta-fluoride, uranium tetrafluoride and uranous oxide has been study by means of the Chevenard's thermo balance. Some data on pyrolysis of synthetic mixtures of intermediate compounds which may occasionally appear during the industrial process, are given. Thermogravimetric methods of control are suggested, usable in interesting products in the uranium metallurgy. (Author) 20 refs.

  8. General Chemistry in Liberal Arts Colleges.

    Science.gov (United States)

    Finholt, Albert E.

    1978-01-01

    Discusses some issues related to chemistry curricula in liberal arts colleges. Among these issues are the nature of a liberal arts curriculum, content of chemistry course, teaching methods, technological aids to teaching, use of the laboratory, and the future of general chemistry teaching in the liberal arts colleges. (HM)

  9. Combined application of extrusion and irradiation technologies: A strategy oriented for green and cost-effective chemistry

    Directory of Open Access Journals (Sweden)

    Ali Ayoub

    2013-02-01

    Full Text Available Reactive extrusion is an attractive green route for cost-effective polymer processing, which has the potential to enhance the commercial viability of biomass-derived materials. In reactive extrusion, compatibilizers can be generated in the blend preparation through polymer-polymer grafting reactions using functionalized polymers. One very interesting new green strategy for processing is the use of intense UV-irradiation to create free radicals and controllable, ultra-fast reactions. It is reasonable to expect that the use of extrusion/irradiation green technology will be an important way to improve properties and compatibility of renewable biomass- derived polymers. We believe that in the future, many more cost-effective, sustainable extrusion/irradiation reaction processes will be developed to replace inefficient conventional biomass conversion procedures and stimulate the bioproduct-based industry.

  10. Smart Cities Will Need Chemistry

    Directory of Open Access Journals (Sweden)

    Alexandru WOINAROSCHY

    2016-06-01

    Full Text Available A smart city is a sustainable and efficient urban centre that provides a high quality of life to its inhabitants through optimal management of its resources. Chemical industry has a key role to play in the sustainable evolution of the smart cities. Additionally, chemistry is at the heart of all modern industries, including electronics, information technology, biotechnology and nano-technology. Chemistry can make the smart cities project more sustainable, more energy efficient and more cost effective. There are six broad critical elements of any smart city: water management systems; infrastructure; transportation; energy; waste management and raw materials consumption. In all these elements chemistry and chemical engineering are deeply involved.

  11. CHARACTERISTICS OF FATIGUE SURFACE MICROCRACK GROWTH IN VICINAL INCLUSION FOR POWDER METALLURGY ALLOYS

    Institute of Scientific and Technical Information of China (English)

    WangXishu; LiYongqiang

    2003-01-01

    Inclusion flaw is one of the worst flaws of powder metallurgy. The inclusion flaw plays an important role in the failure of high temperature turbine materials in aircraft components and automotive parts, especially fatigue failure. In this paper, an experimental investigation of fatigue microcrack propagation in the vicinal inclusion were carried out by the servo-hydraulic fatigue test system with scanning electron microscope (SEM). It has been found from the SEM images that the fatigue surface microcrack occurs in the matrix and inclusion. According to the SEM images, the characteristics of fatigue crack initiation and growth in vicinal inclusion for powder metallurgy alloys are analyzed in detail. The effect of the geometrical shape and material type of surface inclusions on the cracking is also discussed with the finite element method (FEM).

  12. Preparation of Three-Dimensional Graphene Foams Using Powder Metallurgy Templates.

    Science.gov (United States)

    Sha, Junwei; Gao, Caitian; Lee, Seoung-Ki; Li, Yilun; Zhao, Naiqin; Tour, James M

    2016-01-26

    A simple and scalable method which combines traditional powder metallurgy and chemical vapor deposition is developed for the synthesis of mesoporous free-standing 3D graphene foams. The powder metallurgy templates for 3D graphene foams (PMT-GFs) consist of particle-like carbon shells which are connected by multilayered graphene that shows high specific surface area (1080 m(2) g(-1)), good crystallization, good electrical conductivity (13.8 S cm(-1)), and a mechanically robust structure. The PMT-GFs did not break under direct flushing with DI water, and they were able to recover after being compressed. These properties indicate promising applications of PMT-GFs for fields requiring 3D carbon frameworks such as in energy-based electrodes and mechanical dampening.

  13. Estimation and characterization of polycyclic aromatic hydrocarbons from magnesium metallurgy facilities in China.

    Science.gov (United States)

    Nie, Zhiqiang; Yang, Yufei; Tang, Zhenwu; Liu, Feng; Wang, Qi; Huang, Qifei

    2014-11-01

    Field monitoring was conducted to develop a polycyclic aromatic hydrocarbon (PAH) emission inventory for the magnesium (Mg) metallurgy industry in China. PAH emissions in stack gas and fly/bottom ash samples from different smelting units of a typical Mg smelter were measured and compared. Large variations of concentrations, congener patterns, and emission factors of PAHs during the oxidation and reduction stages in the Mg smelter were observed. The measured average emission factor (166,487 μg/t Mg) was significantly higher than those of other industrial sources. Annual emission from Mg metallurgy in 2012 in China was estimated at 116 kg (514 g BaPeq) for PAHs. The results of this study suggest that PAH emission from Mg industries should be considered by local government agencies. These data may be helpful for understanding PAH levels produced by the Mg industry and in developing a PAH inventory.

  14. Structural and electrical properties of copper-nickel-aluminum alloys obtained by conventional powder metallurgy method

    Energy Technology Data Exchange (ETDEWEB)

    Monteiro, Waldemar A.; Carrio, Juan A.G.; Silveira, C.R. da; Pertile, H.K.S., E-mail: fisica.cch@mackenzie.br [Universidade Presbiteriana Mackenzie (UPM/CCH), Sao Paulo, SP (Brazil). Centro de Ciencias e Humanidades. Dept. de Fisica; Silva, L.C.E. da; Buso, S.J., E-mail: jgcarrio@mackenzie.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    This work looked for to search out systematically, in scale of laboratory, copper-nickel-aluminum alloys (Cu-Ni-Al) with conventional powder metallurgy processing, in view of the maintenance of the electric and mechanical properties with the intention of getting electric connectors of high performance or high mechanical damping. After cold uniaxial pressing (1000 kPa), sintering (780 deg C) and convenient homogenization treatments (500 deg C for different times) under vacuum (powder metallurgy), the obtained Cu-Ni-Al alloys were characterized by optical microscopy, electrical conductivity, Vickers hardness. X rays powder diffraction data were collected for the sintered samples in order to a structural and microstructural analysis. The comparative analysis is based on the sintered density, hardness, macrostructures and microstructures of the samples. (author)

  15. [Risk and features of occupational diseases in nonferrous metallurgy workers of Kolsky Transpolar area].

    Science.gov (United States)

    Siurin, S A; Chashchin, V P; Frolova, N M

    2015-01-01

    The study covered data on 977 cases of occupational diseases in 615 workers of nonferrous metallurgy in Kolsky Transpolar area. Findings are high risk of occupational diseases in workers engaged into electrolysis production of aluminium, all nickel reprocessing and pyrometallic copper reprocessing (GR 7.02-10.0). Electrolysis operators and anode operators of aluminium production are more prone to occupational diseases, with bone and muscular disorders (46.8%) prevalent in the morbidity structure. Respiratory diseases are more prevalent (68.2-100%) in the occupational morbidity structure of copper-nickelindustry workers. Conclusion is made on mandatory improvement of the work conditions and more effective individual protective means against occupational hazards in workers of nonferrous metallurgy in Kolsky Transpolar area.

  16. Development of new metal matrix composite electrodes for electrical discharge machining through powder metallurgy process

    Directory of Open Access Journals (Sweden)

    C. Mathalai Sundaram

    2014-12-01

    Full Text Available Electrical discharge machining (EDM is one of the widely used nontraditional machining methods to produce die cavities by the erosive effect of electrical discharges. This method is popular due to the fact that a relatively soft electrically conductive tool electrode can machine hard work piece. Copper electrode is normally used for machining process. Electrode wear rate is the major drawback for EDM researchers. This research focus on fabrication of metal matrix composite (MMC electrode by mixing copper powder with titanium carbide (TiC and Tungsten carbide (WC powder through powder metallurgy process, Copper powder is the major amount of mixing proportion with TiC and WC. However, this paper focus on the early stage of the project where powder metallurgy route was used to determine suitable mixing time, compaction pressure and sintering and compacting process in producing EDM electrode. The newly prepared composite electrodes in different composition are tested in EDM for OHNS steel.

  17. Apparent Electrical Conductivity of Porous Titanium Prepared by the Powder Metallurgy Method

    Institute of Scientific and Technical Information of China (English)

    LI Cheng-Feng; ZHU Zhen-Gang

    2005-01-01

    @@ Porous titanium is produced by the powder metallurgy method. Dependence of the electrical conductivity on the porosity and pore size is investigated and the experimental results are compared with a number of models. It is found that the minimum solid area model could be successfully applied to describe the relationship between the electrical conductivity and the porosity of porous titanium. This kind of conductivity increases with increasing pore sizes.

  18. Efficiency and wear properties of spur gears made of powder metallurgy materials

    OpenAIRE

    Xinmin, Li

    2016-01-01

    Powder metallurgy (PM) is usually used in manufacturing parts with complex geometries, such as gears and structural parts. The main attractions of PM are the high rate of material utilization, environmental friendliness of production, economic advantages (especially for complex geometries), and possibility of obtaining lighter components. To find a wide range of applications and compete with regular steel gears, PM gear transmissions should have good transmission efficiency and wear propertie...

  19. Microstructurally sensitive crack nucleation around inclusions in powder metallurgy nickel based superalloys

    OpenAIRE

    Jiang, J; Yang, J; Zhang, T.; J Zou; Wang,Y.,; Dunne, F.P.E.; Britton, T. B.

    2016-01-01

    ? 2016 Acta Materialia Inc.Nickel-based superalloys are used in high strength, high-value applications, such as gas turbine discs in aero engines. In these applications the integrity of the disc is critical and therefore understanding crack initiation mechanisms is of high importance. With an increasing trend towards powder metallurgy routes for discs, sometimes unwanted non-metallic inclusions are introduced during manufacture. These inclusions vary in size from ?10??m to 200??m which is com...

  20. Chemistry and lithography

    CERN Document Server

    Okoroanyanwu, Uzodinma

    2011-01-01

    This is a unique book, combining chemistry and physics with technology and history in a way that is both enlightening and lively. No other book in the field of lithography has as much breadth. Highly recommended for anyone interested in the broad application of chemistry to lithography. --Chris Mack, Gentleman Scientist. This book provides a comprehensive treatment of the chemical phenomena in lithography in a manner that is accessible to a wide readership. The book presents topics on the optical and charged particle physics practiced in lithography, with a broader view of how the marriage bet

  1. A millennium of metallurgy recorded by lake sediments from Morococha, Peruvian Andes.

    Science.gov (United States)

    Cooke, Colin A; Abbott, Mark B; Wolfe, Alexander P; Kittleson, John L

    2007-05-15

    To date, information concerning pre-Colonial metallurgy in South America has largely been limited to the archaeological record of artifacts. Here, we reconstruct a millennium of smelting activity in the Peruvian Andes using the lake-sediment stratigraphy of atmospherically derived metals (Pb, Zn, Cu, Ag, Sb, Bi, and Ti) and lead isotopic ratios (206Pb/ 207Pb) associated with smelting from the Morococha mining region in the central Peruvian Andes. The earliest evidence for metallurgy occurs ca. 1000 A.D., coinciding with the fall of the Wari Empire and decentralization of local populations. Smelting during this interval appears to have been aimed at copper and copper alloys, because of large increases in Zn and Cu relative to Pb. A subsequent switch to silver metallurgy under Inca control (ca. 1450 to conquest, 1533 A.D.) is indicated by increases in Pb, Sb, and Bi, a conclusion supported by further increases of these metals during Colonial mining, which targeted silver extraction. Rapid development of the central Andes during the 20th century raised metal burdens by an order of magnitude above previous levels. Our results represent the first evidence for pre-Colonial smelting in the central Peruvian Andes, and corroborate the sensitivity of lake sediments to pre-Colonial metallurgical activity suggested by earlier findings from Bolivia.

  2. Properties of WZ21 (%wt) alloy processed by a powder metallurgy route.

    Science.gov (United States)

    Cabeza, Sandra; Garcés, Gerardo; Pérez, Pablo; Adeva, Paloma

    2015-06-01

    Microstructure, mechanical properties and corrosion behaviour of WZ21 (%wt) alloy prepared by a powder metallurgy route from rapidly solidified powders have been studied. Results were compared to those of the same alloy prepared through a conventional route of casting and extrusion. The microstructure of the extruded ingot consisted of α-Mg grains and Mg3Zn3Y2 (W-phase) and LPSO-phase particles located at grain boundaries. Moreover, stacking faults were also observed within α-Mg grains. The alloy processed by the powder metallurgy route exhibited a more homogeneous and finer microstructure, with a grain size of 2 μm. In this case W-phase and Mg24Y5 phase were identified, but not the LPSO-phase. The microstructural refinement induced by the use of rapidly solidified powders strengthened the alloy at room temperature and promoted superplasticity at higher strain rates. Corrosion behaviour in PBS medium evidenced certain physical barrier effect of the almost continuous arrangements of second phases aligned along the extrusion direction in conventionally processed WZ21 alloy, with a stable tendency around 7 mm/year. On the other hand, powder metallurgy processing promoted significant pitting corrosion, inducing accelerated corrosion rate during prolonged immersion times.

  3. Investment casting or powder metallurgy – the ecological aspect

    Directory of Open Access Journals (Sweden)

    J. Tomasik

    2009-04-01

    Full Text Available The paper presents an analysis of manufacturing methods of material-saving products in relation to investment castings and sinteredpowder technology. Surface microgeometry, shape accuracy, performance parameters, manufacturing costs and energy consumption weretaken into account to make the optimal choice. The analysis was conducted by comparing test results for sintered powder products basedon Distaloy AB alloy that consists of 0.55% C, 1.5% Cu, 1.75% Ni and 0.5% Mo and investment castings made of high alloy cast steel andnodular cast iron. The analysis made it possible to choose the best technology, considering also the ecological aspect.

  4. Recovery of Value Metals From Waste Residue From Nickel Metallurgy%从炼镍废渣中综合回收有价金属

    Institute of Scientific and Technical Information of China (English)

    肖景波; 夏娇彬; 陈居玲

    2014-01-01

    The sulfuric acid was used to decompose the waste residue from nickel metallurgy ,sodium hydroxide was used to treat the sulfuric acid decompose residue for prepating sodium silicate and highly dispersed silica w hite .T he high-purity iron oxide and nickel concentrate can be obtained using the sulfuric acid solution .In addition ,after the further purify ,magnesium hydroxide products can be obtained by ammonia precipitation process .The best process conditions and technological process were determined .%研究了以硫酸分解镍渣,用氢氧化钠处理酸解渣制取高分散性白炭黑,以及用酸解液制备高纯氧化铁和镍精矿。将溶液进一步净化处理制取氢氧化镁。试验确定了最佳工艺条件及工艺流程。

  5. Powder Metallurgy of Uranium Alloy Fuels for TRU-Burning Reactors Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    McDeavitt, Sean M

    2011-04-29

    Overview Fast reactors were evaluated to enable the transmutation of transuranic isotopes generated by nuclear energy systems. The motivation for this was that TRU isotopes have high radiotoxicity and relatively long half-lives, making them unattractive for disposal in a long-term geologic repository. Fast reactors provide an efficient means to utilize the energy content of the TRUs while destroying them. An enabling technology that requires research and development is the fabrication metallic fuel containing TRU isotopes using powder metallurgy methods. This project focused upon developing a powder metallurgical fabrication method to produce U-Zr-transuranic (TRU) alloys at relatively low processing temperatures (500ºC to 600ºC) using either hot extrusion or alpha-phase sintering for charecterization. Researchers quantified the fundamental aspects of both processing methods using surrogate metals to simulate the TRU elements. The process produced novel solutions to some of the issues relating to metallic fuels, such as fuel-cladding chemical interactions, fuel swelling, volatility losses during casting, and casting mold material losses. Workscope There were two primary tasks associated with this project: 1. Hot working fabrication using mechanical alloying and extrusion • Design, fabricate, and assemble extrusion equipment • Extrusion database on DU metal • Extrusion database on U-10Zr alloys • Extrusion database on U-20xx-10Zr alloys • Evaluation and testing of tube sheath metals 2. Low-temperature sintering of U alloys • Design, fabricate, and assemble equipment • Sintering database on DU metal • Sintering database on U-10Zr alloys • Liquid assisted phase sintering on U-20xx-10Zr alloys Appendices Outline Appendix A contains a Fuel Cycle Research & Development (FCR&D) poster and contact presentation where TAMU made primary contributions. Appendix B contains MSNE theses and final defense presentations by David Garnetti and Grant Helmreich

  6. Powder Metallurgy of Uranium Alloy Fuels for TRU-Burning Reactors Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    McDeavitt, Sean M

    2011-04-29

    Overview Fast reactors were evaluated to enable the transmutation of transuranic isotopes generated by nuclear energy systems. The motivation for this was that TRU isotopes have high radiotoxicity and relatively long half-lives, making them unattractive for disposal in a long-term geologic repository. Fast reactors provide an efficient means to utilize the energy content of the TRUs while destroying them. An enabling technology that requires research and development is the fabrication metallic fuel containing TRU isotopes using powder metallurgy methods. This project focused upon developing a powder metallurgical fabrication method to produce U-Zr-transuranic (TRU) alloys at relatively low processing temperatures (500ºC to 600ºC) using either hot extrusion or alpha-phase sintering for charecterization. Researchers quantified the fundamental aspects of both processing methods using surrogate metals to simulate the TRU elements. The process produced novel solutions to some of the issues relating to metallic fuels, such as fuel-cladding chemical interactions, fuel swelling, volatility losses during casting, and casting mold material losses. Workscope There were two primary tasks associated with this project: 1. Hot working fabrication using mechanical alloying and extrusion • Design, fabricate, and assemble extrusion equipment • Extrusion database on DU metal • Extrusion database on U-10Zr alloys • Extrusion database on U-20xx-10Zr alloys • Evaluation and testing of tube sheath metals 2. Low-temperature sintering of U alloys • Design, fabricate, and assemble equipment • Sintering database on DU metal • Sintering database on U-10Zr alloys • Liquid assisted phase sintering on U-20xx-10Zr alloys Appendices Outline Appendix A contains a Fuel Cycle Research & Development (FCR&D) poster and contact presentation where TAMU made primary contributions. Appendix B contains MSNE theses and final defense presentations by David Garnetti and Grant Helmreich

  7. Quantum chemistry

    CERN Document Server

    Lowe, John P

    1993-01-01

    Praised for its appealing writing style and clear pedagogy, Lowe's Quantum Chemistry is now available in its Second Edition as a text for senior undergraduate- and graduate-level chemistry students. The book assumes little mathematical or physical sophistication and emphasizes an understanding of the techniques and results of quantum chemistry, thus enabling students to comprehend much of the current chemical literature in which quantum chemical methods or concepts are used as tools. The book begins with a six-chapter introduction of standard one-dimensional systems, the hydrogen atom,

  8. Gansu Focuses on Cultivating Nonferrous Metallurgy New Material Industry

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    By adopting 8 fields such as new materials as cultivation focus,regarding 16 enterprises including Gansu Rare Earth New Material Co.,Ltd,Lanzhou Jinchuan New Material Technology Co.,Ltd as the first batch of backbone enterprises to support,Gansu kicked off overall besiege battle for implementing strategic emerging industries.Provincial officials pointed out that through creating new

  9. Introductory Chemistry

    OpenAIRE

    Baron, Mark; Gonzalez-Rodriguez, Jose; Stevens, Gary; Gray, Nathan; Atherton, Thomas; Winn, Joss

    2010-01-01

    Teaching and Learning resources for the 1st Year Introductory Chemistry course (Forensic Science). 30 credits. These are Open Educational Resources (OER), made available for re-use under a Creative Commons license.

  10. Materials Chemistry

    CERN Document Server

    Fahlman, Bradley D

    2011-01-01

    The 2nd edition of Materials Chemistry builds on the strengths that were recognized by a 2008 Textbook Excellence Award from the Text and Academic Authors Association (TAA). Materials Chemistry addresses inorganic-, organic-, and nano-based materials from a structure vs. property treatment, providing a suitable breadth and depth coverage of the rapidly evolving materials field. The 2nd edition continues to offer innovative coverage and practical perspective throughout. After briefly defining materials chemistry and its history, seven chapters discuss solid-state chemistry, metals, semiconducting materials, organic "soft" materials, nanomaterials, and materials characterization. All chapters have been thoroughly updated and expanded with, for example, new sections on ‘soft lithographic’ patterning, ‘click chemistry’ polymerization, nanotoxicity, graphene, as well as many biomaterials applications. The polymer and ‘soft’ materials chapter represents the largest expansion for the 2nd edition. Each ch...

  11. Nuclear Chemistry.

    Science.gov (United States)

    Chemical and Engineering News, 1979

    1979-01-01

    Provides a brief review of the latest developments in nuclear chemistry. Nuclear research today is directed toward increased activity in radiopharmaceuticals and formation of new isotopes by high-energy, heavy-ion collisions. (Author/BB)

  12. Cluster Chemistry

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    @@ Cansisting of eight scientists from the State Key Laboratory of Physical Chemistry of Solid Surfaces and Xiamen University, this creative research group is devoted to the research of cluster chemistry and creation of nanomaterials.After three-year hard work, the group scored a series of encouraging progresses in synthesis of clusters with special structures, including novel fullerenes, fullerene-like metal cluster compounds as well as other related nanomaterials, and their properties study.

  13. Green Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Collison, Melanie

    2011-05-15

    Green chemistry is the science of chemistry used in a way that will not use or create hazardous substances. Dr. Rui Resendes is working in this field at GreenCentre Canada, an offshoot of PARTEQ Innovations in Kingston, Ontario. GreenCentre's preliminary findings suggest their licensed product {sup S}witchable Solutions{sup ,} featuring 3 classes of solvents and a surfactant, may be useful in bitumen oil sands extraction.

  14. The extractive metallurgy of south africa's platinum ores

    Science.gov (United States)

    Cramer, Larry A.

    2001-10-01

    The extraction technology for platinum-group metals (PGMs) has changed dramatically in the last 80 years, and the changes are likely to continue for years to come. This article will review advances in PGM extraction, including developments in semi-autogenous and fully autogenous milling; flotation equipment applications for treating high-chrome ores; increases in power densities for future smelting furnaces, and new methods for meeting rising environmental standards.

  15. Processing of Elemental Titanium by Powder Metallurgy Techniques

    OpenAIRE

    Bolzoni, Leandro; Ruiz Navas, Elisa María; Gordo Odériz, Elena

    2013-01-01

    [Poster] 6th International Light Metals Technology Conference (LMT2013), 24-26 July, Windsord (UK) Titanium is characterised by an outstanding combination of properties like high strength, low density, good corrosion resistance and biocompatibility. Nonetheless, widespread employment of titanium at the industrial level, especially in the automotive industry, has not been achieved yet because of its high extraction and production costs. Consequently, titanium finds applications mainly in hi...

  16. Towards Bildung-Oriented Chemistry Education

    Science.gov (United States)

    Sjöström, Jesper

    2013-07-01

    This paper concerns Bildung-oriented chemistry education, based on a reflective and critical discourse of chemistry. It is contrasted with the dominant type of chemistry education, based on the mainstream discourse of chemistry. Bildung-oriented chemistry education includes not only content knowledge in chemistry, but also knowledge about chemistry, both about the nature of chemistry and about its role in society. In 2004 Mahaffy suggested a tetrahedron model based on Johnstone's chemical triangle. The latter represents the formal aspects of chemistry teaching (macro, submicro, and symbolic) and the top of the tetrahedron represents a human element. In the present paper the following subdivision of the top is suggested (starting from the bottom): (1) applied chemistry, (2) socio-cultural context, and (3) critical-philosophic approach. The professional identity of the Bildung-oriented chemistry teacher differs from that of the chemist and is informed by research fields such as Philosophy of Chemistry, Science and Technology Studies, and Environmental Education. He/she takes a socio-critical approach to chemistry, emphasising both the benefits and risks of chemistry and its applications.

  17. From organic chemistry to fat and oil chemistry*

    Directory of Open Access Journals (Sweden)

    Deffense Etienne

    2009-01-01

    Full Text Available With his work on animal fat and identification of fatty acids, Chevreul was a pioneer in organic chemistry. As Chevreul, I had a passion for organic chemistry too. It was then, an honour and a pleasure to present in 2008 at EFL in Athens this presentation entitled “From organic chemistry to fat and oil chemistry” because my background in organic chemistry helped me all along my professional career to understand and implement new developments related to oil and fat technology and processing. Among the topics which I worked out, I highlighted more particularly the following subjects: the degumming chemistry of oil and fat; the improvement of physical refining; a new chemical analytical tool for the dry fractionation; new development in the dry fractionation

  18. Significant steps in the evolution of analytical chemistry--is the today's analytical chemistry only chemistry?

    Science.gov (United States)

    Karayannis, Miltiades I; Efstathiou, Constantinos E

    2012-12-15

    In this review the history of chemistry and specifically the history and the significant steps of the evolution of analytical chemistry are presented. In chronological time spans, covering the ancient world, the middle ages, the period of the 19th century, and the three evolutional periods, from the verge of the 19th century to contemporary times, it is given information for the progress of chemistry and analytical chemistry. During this period, analytical chemistry moved gradually from its pure empirical nature to more rational scientific activities, transforming itself to an autonomous branch of chemistry and a separate discipline. It is also shown that analytical chemistry moved gradually from the status of exclusive serving the chemical science, towards serving, the environment, health, law, almost all areas of science and technology, and the overall society. Some recommendations are also directed to analytical chemistry educators concerning the indispensable nature of knowledge of classical analytical chemistry and the associated laboratory exercises and to analysts, in general, why it is important to use the chemical knowledge to make measurements on problems of everyday life.

  19. Fuel resources and their influence on emission from the plants of the Ministry of Metallurgy and Mechanical Engineering. [Czechoslovakia

    Energy Technology Data Exchange (ETDEWEB)

    Moucha, B.

    1986-02-01

    Environmental pollution in Czechoslovakia and pollution from metallurgy are discussed. Environmental pollution from metallurgical plants in Czechoslovakia is influenced by types of fuels used by this branch of the national economy. From 1980 to 1990 proportion of solid fuels in the energy balance of metallurgy will increase from 67.5% to 82.5%, proportion of liquid fuels will decrease from 14.2% to 5.3%, proportion of gaseous fuels will increase from 9.3% to 12.2%. Increasing role of coal or coke in metallurgy causes an increase in environmental pollution, especially emission of sulfur dioxide, while increasing consumption of gaseous fuels reduces environmental pollution. Decrease in crude oil consumption reduces hazards of water pollution by oils. Sources of air pollution by dusts and gases in metallurgy are analyzed: agglomeration, coking plants, blast furnaces, steel works, power plants. Dust, sulfur dioxide, carbon monoxide and nitrogen oxides emitted by each type of plant are analyzed. Effects of air pollution control on air pollution from metallurgy in Czechoslovakia are discussed. Statistical data on air pollution are shown in 4 tables.

  20. Mathematical Modeling: An Integrated Algebra, Physics and Chemistry Workshop for Teachers as a Tool for Recruiting Science, Technology and Mathematics Students.

    Science.gov (United States)

    Obot, V.; Reiff, P.; Morris, P. A.; Humphrey, M.

    2004-12-01

    Based on the philosophy that there exists an artificial boundary between mathematics and the sciences, we have developed a series of workshops and modules on mathematical modeling suitable as teaching examples in secondary schools. The workshops is a 60-hour workshop held on the campus of Texas Southern University during the summer months, followed by a series of follow-up workshops on Saturdays during the academic year. Texas Southern University is a Historically Black University devoted to urban programming. The workshops use experimental and observational data from various fields with particular emphasis on chemistry, physics, earth and space sciences. The data is used to construct mathematical models. In the process of constructing the model, the student learns the appropriate mathematical and scientific concepts. We have studied linear, exponential and logarithmic functions, and using planetary data, derived and discussed Kepler's laws. We have learned how to balance chemical equations as a solution to a system of equations. We have studied and modeled electromagnetic waves using ham radio as our launching pad. Judging from participant evaluations, follow up workshops and classroom visits; teachers who participated in this workshop have been re-invigorated in their teaching. They have incorporated our examples in their teaching. They have reported increased attentiveness and excitement regarding science and mathematics from their students. It appears that this approach have caused some students to think seriously about pursuing science and engineering careers. An added benefit of this program is that the teachers have invited us and affiliated scientist into their classrooms for demonstrations. This gives the students an opportunity to interact with actual scientist and engineers. These interactions have resulted in several of the students being invited to serve as summer interns in our laboratories. For the past three years, almost all of the interns have

  1. Ullmann's Encyclopedia of Industrial Chemistry.

    Science.gov (United States)

    Chadwick, Sharon S.

    1988-01-01

    This review compares "Ullmann's Encyclopedia of Industrial Chemistry" with the "Kirk-Othmer Encyclopedia of Chemical Technology," two prominent encyclopedias of chemical technology and industry. Cost, quantity of information, organization, illustrations, authorship, abbreviations, online availability, and content of articles are discussed. (MES)

  2. Ullmann's Encyclopedia of Industrial Chemistry.

    Science.gov (United States)

    Chadwick, Sharon S.

    1988-01-01

    This review compares "Ullmann's Encyclopedia of Industrial Chemistry" with the "Kirk-Othmer Encyclopedia of Chemical Technology," two prominent encyclopedias of chemical technology and industry. Cost, quantity of information, organization, illustrations, authorship, abbreviations, online availability, and content of articles are discussed. (MES)

  3. Quo vadis, analytical chemistry?

    Science.gov (United States)

    Valcárcel, Miguel

    2016-01-01

    This paper presents an open, personal, fresh approach to the future of Analytical Chemistry in the context of the deep changes Science and Technology are anticipated to experience. Its main aim is to challenge young analytical chemists because the future of our scientific discipline is in their hands. A description of not completely accurate overall conceptions of our discipline, both past and present, to be avoided is followed by a flexible, integral definition of Analytical Chemistry and its cornerstones (viz., aims and objectives, quality trade-offs, the third basic analytical reference, the information hierarchy, social responsibility, independent research, transfer of knowledge and technology, interfaces to other scientific-technical disciplines, and well-oriented education). Obsolete paradigms, and more accurate general and specific that can be expected to provide the framework for our discipline in the coming years are described. Finally, the three possible responses of analytical chemists to the proposed changes in our discipline are discussed.

  4. Net-Shape HIP Powder Metallurgy Components for Rocket Engines

    Science.gov (United States)

    Bampton, Cliff; Goodin, Wes; VanDaam, Tom; Creeger, Gordon; James, Steve

    2005-01-01

    True net shape consolidation of powder metal (PM) by hot isostatic pressing (HIP) provides opportunities for many cost, performance and life benefits over conventional fabrication processes for large rocket engine structures. Various forms of selectively net-shape PM have been around for thirty years or so. However, it is only recently that major applications have been pursued for rocket engine hardware fabricated in the United States. The method employs sacrificial metallic tooling (HIP capsule and shaped inserts), which is removed from the part after HIP consolidation of the powder, by selective acid dissolution. Full exploitation of net-shape PM requires innovative approaches in both component design and materials and processing details. The benefits include: uniform and homogeneous microstructure with no porosity, irrespective of component shape and size; elimination of welds and the associated quality and life limitations; removal of traditional producibility constraints on design freedom, such as forgeability and machinability, and scale-up to very large, monolithic parts, limited only by the size of existing HIP furnaces. Net-shape PM HIP also enables fabrication of complex configurations providing additional, unique functionalities. The progress made in these areas will be described. Then critical aspects of the technology that still require significant further development and maturation will be discussed from the perspective of an engine systems builder and end-user of the technology.

  5. Promoting sustainability through green chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Kirchhoff, Mary M. [American Chemical Society, 1155 Sixteenth Street, NW, Washington, DC 20036 (United States)

    2005-06-15

    Green chemistry is an important tool in achieving sustainability. The implementation of green chemistry, the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances, is essential if the expanding global population is to enjoy an increased standard of living without having a negative impact on the health of the planet. Cleaner technologies will allow the chemical enterprise to provide society with the goods and services on which it depends in an environmentally responsible manner. Green chemistry provides solutions to such global challenges as climate change, sustainable agriculture, energy, toxics in the environment, and the depletion of natural resources. A collaborative effort by industry, academia, and government is needed to promote the adoption of the green chemistry technologies necessary to achieve a sustainable society.

  6. Current status and future perspectives of electron interactions with molecules, clusters, surfaces, and interfaces [Workshop on Fundamental challenges in electron-driven chemistry; Workshop on Electron-driven processes: Scientific challenges and technological opportunities

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Kurt H.; McCurdy, C. William; Orlando, Thomas M.; Rescigno, Thomas N.

    2000-09-01

    This report is based largely on presentations and discussions at two workshops and contributions from workshop participants. The workshop on Fundamental Challenges in Electron-Driven Chemistry was held in Berkeley, October 9-10, 1998, and addressed questions regarding theory, computation, and simulation. The workshop on Electron-Driven Processes: Scientific Challenges and Technological Opportunities was held at Stevens Institute of Technology, March 16-17, 2000, and focused largely on experiments. Electron-molecule and electron-atom collisions initiate and drive almost all the relevant chemical processes associated with radiation chemistry, environmental chemistry, stability of waste repositories, plasma-enhanced chemical vapor deposition, plasma processing of materials for microelectronic devices and other applications, and novel light sources for research purposes (e.g. excimer lamps in the extreme ultraviolet) and in everyday lighting applications. The life sciences are a rapidly advancing field where the important role of electron-driven processes is only now beginning to be recognized. Many of the applications of electron-initiated chemical processes require results in the near term. A large-scale, multidisciplinary and collaborative effort should be mounted to solve these problems in a timely way so that their solution will have the needed impact on the urgent questions of understanding the physico-chemical processes initiated and driven by electron interactions.

  7. Parallel chemistry in the 21st century.

    Science.gov (United States)

    Long, Alan

    2012-09-01

    The tool chest of techniques, methodologies, and equipment for conducting parallel chemistry is larger than ever before. Improvements in the laboratory and developments in computational chemistry have enabled compound library design at the desks of medicinal chemists. This unit includes a brief background in combinatorial/parallel synthesis chemistry, along with a discussion of evolving technologies for both solid- and solution-phase chemistry. In addition, there are discussions on designing compound libraries, acquisition/procurement of compounds and/or reagents, the chemistry and equipment used for chemical production, purification, sample handling, and data analysis.

  8. Handbook of heterocyclic chemistry

    National Research Council Canada - National Science Library

    Katritzky, Alan R

    2010-01-01

    ... Heterocyclic Chemistry I (1984) Comprehensive Heterocyclic Chemistry II (1996) Comprehensive Heterocyclic Chemistry III (2008) Comprehensive Organic Functional Group Transformations I (1995) Compreh...

  9. What is the connection between metallurgy and environmental issues? Could a new discipline emerge from this confrontation?

    Directory of Open Access Journals (Sweden)

    Birat Jean-Pierre

    2013-11-01

    Full Text Available In neoclassical economics, the environment is an externality and environmental issues are treated as an add-on feature. In metallurgy, the environment is handled in a similar way, for similar reasons: environmental issues are both external to the core themes of metallurgy and to the economics of process metallurgy. Environmental issues range from corrosion, to generation of by-products, to air and water emissions, to environmental footprints (carbon footprint, water footprint, etc., a measure of the burdens/liabilities that metals production and use impose on the “planet”, to social footprint, a measure of the assets brought about by the economic activities they generate, and to recycling, re-use and nega-use issues.

  10. Chemistry in Bioinformatics

    Science.gov (United States)

    Murray-Rust, Peter; Mitchell, John BO; Rzepa, Henry S

    2005-01-01

    Chemical information is now seen as critical for most areas of life sciences. But unlike Bioinformatics, where data is openly available and freely re-usable, most chemical information is closed and cannot be re-distributed without permission. This has led to a failure to adopt modern informatics and software techniques and therefore paucity of chemistry in bioinformatics. New technology, however, offers the hope of making chemical data (compounds and properties) free during the authoring process. We argue that the technology is already available; we require a collective agreement to enhance publication protocols. PMID:15941476

  11. Chemistry in Bioinformatics

    Directory of Open Access Journals (Sweden)

    Mitchell John

    2005-06-01

    Full Text Available Abstract Chemical information is now seen as critical for most areas of life sciences. But unlike Bioinformatics, where data is openly available and freely re-usable, most chemical information is closed and cannot be re-distributed without permission. This has led to a failure to adopt modern informatics and software techniques and therefore paucity of chemistry in bioinformatics. New technology, however, offers the hope of making chemical data (compounds and properties free during the authoring process. We argue that the technology is already available; we require a collective agreement to enhance publication protocols.

  12. Microstructures and mechanical properties of hot isostatically pressed powder metallurgy Alloy APK-1

    Science.gov (United States)

    Prakash, T. L.; Chari, Y. N.; Rao, E. S. Bhagiradha; Thamburaj, R.

    1983-03-01

    The influence of Hot Isostatic Pressing (HIP) and heat treatment parameters on the microstructure and mechanical properties of powder metallurgy alloy APK-1 (a low carbon modification of Astroloy) has been investigated. Poor mechanical properties result if carbide networks are present along the prior particle boundaries (PPBs). These networks which form during powder consolidation can be avoided by manipulating HIP parameters. Heat treatments which produce a large volume fraction of fine γ’ make this alloy susceptible to environment-assisted tensile embrittlement around 760 °C.

  13. Low cycle fatigue improvement of powder metallurgy titanium alloy through thermomechanical treatment

    Institute of Scientific and Technical Information of China (English)

    LIU Bin; LIU Yong; HE Xiao-yu; TANG Hui-ping; CHEN Li-fang

    2008-01-01

    A low-cost β type Ti-1.5Fe-6.8Mo-4.8Al-1.2Nd (mass fraction, %)(T12LCC) alloy was produced by blended elemental powder metallurgy(P/M) method and subsequent thermomechanical treatment. Low cycle fatigue(LCF) behavior of P/M T12LCC alloy before and after thermomechanical treatment was studied. The results show that the LCF resistance of P/M titanium alloy is significantly enhanced through the thermomechanical treatment. The mechanisms for the improvement of LCF behavior are attributed to the elimination of residual pores, the microstructure refining and homogenization.

  14. An Overview of Internal Fixation Implant Metallurgy and Galvanic Corrosion Effects.

    Science.gov (United States)

    Koh, Justin; Berger, Aaron; Benhaim, Prosper

    2015-08-01

    Orthopedic and hand surgery implants for internal fixation of fractures have evolved substantially over the past 50 years. Newer metal compositions have been used, and new standards have been applied to older alloys, resulting in modern implants with unique physical properties and better clinical performances. Conventional wisdom has long dictated that implanting different metals should be avoided, but few guidelines exist regarding the safety of using in proximity implant systems of dissimilar metals. To better characterize the landscape of internal fixation implant metallurgy, we have compiled the recommendations and conclusions of the currently available and pertinent literature.

  15. Accelerated Near-Threshold Fatigue Crack Growth Behavior of an Aluminum Powder Metallurgy Alloy

    Science.gov (United States)

    Piascik, Robert S.; Newman, John A.

    2002-01-01

    Fatigue crack growth (FCG) research conducted in the near threshold regime has identified a room temperature creep crack growth damage mechanism for a fine grain powder metallurgy (PM) aluminum alloy (8009). At very low DK, an abrupt acceleration in room temperature FCG rate occurs at high stress ratio (R = Kmin/Kmax). The near threshold accelerated FCG rates are exacerbated by increased levels of Kmax (Kmax less than 0.4 KIC). Detailed fractographic analysis correlates accelerated FCG with the formation of crack-tip process zone micro-void damage. Experimental results show that the near threshold and Kmax influenced accelerated crack growth is time and temperature dependent.

  16. A TECHNIQUE FOR IMPROVING THE TOUGHNESS OF Al-Li POWDER METALLURGY ALLOYS

    OpenAIRE

    1987-01-01

    A technique has been developed for increasing the toughness of Al-Li products made by powder metallurgy. The technique which involves the addition of unalloyed aluminum powder to Al-Li powder before compaction was evaluated with Al-Li-Cu-Mg-Zr alloys (Al 8090), and Al-Li-Zn-Cu-Mg-Zr and Al-Li-Mg-Si-Cr alloys . The addition of 15% aluminum to Al 8090 aged at 422K for 40 h produced an increase in impact toughness of 215% at the expense of a drop in yield strength of 11%. The Al-Li-Mg-Si-Cr allo...

  17. Powder metallurgy processing of Ni-Co base electrodes for application in water electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Assis, O.B.G. [EMBRAPA Agricultural Instrumentation, Sao Carlos, SP (Brazil); Crnkovic, F.C.; Machado, R.; Avaca, L.A.; Ferrante, M.; Machado, S.A.S.

    1999-07-01

    Electrodes of Co, Ni and Ni{sub 50}Co{sub 50} were produced by powder metallurgy techniques aiming at their application as cathodes for water electrolysis system. Sintering was carried out in vacuum/argon atmosphere at low temperature to keep some residual porosity to enhance surface electroactivity by an increase of the geometric area. The Ni-Co alloying was obtained by mechanical synthesis, making use of the appropriated route. The final electrodes presented porosity around 12% where the electrochemical tests presented increasing in the critical peak when compared with electroplated flat samples. (orig.) 11 refs.

  18. Physical metallurgy: Scientific school of the Academician V.M. Schastlivtsev

    Science.gov (United States)

    Tabatchikova, T. I.

    2016-04-01

    This paper is to honor Academician Vadim Mikhailovich Schastlivtsev, a prominent scientist in the field of metal physics and materials science. The article comprises an analysis of the topical issues of the physical metallurgy of the early 21st century and of the contribution of V.M. Schastlivtsev and of his school to the science of phase and structural transformations in steels. In 2015, Vadim Mikhailovich celebrates his 80th birthday, and this paper is timed to this honorable date. The list of his main publications is given in it.

  19. Electron microscopy study of microtexture in Cu-Al-Ni shape memory alloys processed by powder metallurgy

    Science.gov (United States)

    Rodriguez, P. P.; San Jean, J.; Iza-Mendia, A.; Recarte, V.; Pérez-Landazabal, J. J.; No, M. L.

    2003-10-01

    Cu-AI-Ni shape memory alloys processed by powder metallurgy show very good thermomechanical properties, being the mechanical behavior similar to the one observed in single crystals. In this paper we present the microstructural characterization of a sample elaborated by powder metallurgy in two different stages of the process: after being compacted by Hot Isostatic Pressing (HIP) and after compaction and hot rolling, in order to find the microscopic mechanisms responsible of their mechanical behavior. The characterization has been carried out by means of Scanning Electron Microscopy using Backscattered Electron Imaging (SEM-BSE) and Electron BackScattered Diffraction (EBSD), as well as Transmission Electron Microscopy (TEM).

  20. Striking a Balance: Experiment and Concept in Undergraduate Inorganic Chemistry.

    Science.gov (United States)

    Frey, John E.

    1990-01-01

    Described is an inorganic chemistry course based on the premise that a balanced understanding of inorganic chemistry requires knowledge of the experimental, theoretical, and technological aspects of the subject. A detailed description of lectures and laboratories is included. (KR)

  1. Striking a Balance: Experiment and Concept in Undergraduate Inorganic Chemistry.

    Science.gov (United States)

    Frey, John E.

    1990-01-01

    Described is an inorganic chemistry course based on the premise that a balanced understanding of inorganic chemistry requires knowledge of the experimental, theoretical, and technological aspects of the subject. A detailed description of lectures and laboratories is included. (KR)

  2. Finding the Most Efficient Technology Transfer Route Using Dijkstra Algorithm to Foster Innovation: The Case of Essential Oil Developments in the Research Center for Chemistry at the Indonesian Institute of Sciences

    Directory of Open Access Journals (Sweden)

    Arief Ameir Rahman Setiawan

    2016-07-01

    Full Text Available Innovation is one of the most critical issues in research institutions which can be performed through certain routes within the technology transfer mechanism. As the demands of research implementation are increasing, a better mechanism should be deployed to foster innovation. This study will investigate the possibilities for technology transfer mechanism improvements by (i identifying a number of steps required for innovation; (ii measuring the efficiency of each step; and (iii exploring the most efficient routes to innovate through the Dijkstra algorithm. Cases of research on essential oils and derivatives in the Research Center for Chemistry (RCC of the Indonesian Institute of Sciences (LIPI will be examined as the working example for the study. As a result of this study, a model containing a recommended sequence for the most efficient steps to innovation can be proposed. Using the proposed model, the efficiency rate of the technology transfer mechanism was increased twice, suggesting the possibility of stimulating innovation performance.

  3. A review of the physical metallurgy related to the hot press forming of advanced high strength steel

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Dong W.; Kim, Han S.; De Cooman, C. [Pohang Univ. of Science and Technology, Pohang (Korea). Graduate Inst. of Ferrous Technology

    2009-03-15

    The automotive industry requirements for vehicle weight reduction, weight containment, improved part functionality and passenger safety have resulted in the increased use of steel grades with a fully martensitic microstructure. These steel grades are essential to improve the anti-intrusion resistance of automotive body parts and the related passenger safety during car collisions. Standard advanced high strength steel (AHSS) grades are notoriously difficult to be press formed; they are characterized by elastic springback, poor stretch flangeability and low hole expansion ratios. Hot press forming has therefore received much attention recently as an alternative technology to produce AHSS automotive parts. In this contribution, the physical metallurgy principles of the hot press forming process are reviewed. The effect of composition on CCT curves of standard CMnB hot press forming steels is discussed taking the deformation during press forming into account. Furthermore, the effect of the static strain ageing processes occurring during the paint baking cycle on the in-service mechanical properties of press hardened steel will be presented. The influence of temperate and strain rate on the flow stress during press forming and the final room temperature mechanical properties will be discussed. Moreover, the issues related to coatings on B-alloyed CMn hot press forming steel will be critically reviewed. In particular the combined effects of thermal cycle and deformation on the degradation of the Al-10%Si coating will be discussed in detail. Finally, the properties of both Al-based and Zn-based coating systems are compared, and the possibility of the formation of a diffusion barrier during press forming is discussed. (orig.)

  4. Mechanisms of fatigue crack retardation following single tensile overloads in powder metallurgy aluminum alloys

    Science.gov (United States)

    Bray, G. H.; Reynolds, A. P.; Starke, E. A., Jr.

    1992-01-01

    In ingot metallurgy (IM) alloys, the number of delay cycles following a single tensile overload typically increases from a minimum at an intermediate baseline stress intensity range, Delta-K(B), with decreasing Delta-K(B) approaching threshold and increasing Delta-K(B) approaching unstable fracture to produce a characteristic 'U' shaped curve. Two models have been proposed to explain this behavior. One model is based on the interaction between roughness and plasticity-induced closure, while the other model only utilizes plasticity-induced closure. This article examines these models, using experimental results from constant amplitude and single overload fatigue tests performed on two powder metallurgy (PM) aluminum alloys, AL-905XL and AA 8009. The results indicate that the 'U'-shaped curve is primarily due to plasticity-induced closure, and that the plasticity-induced retardation effect is through-thickness in nature, occurring in both the surface and interior regions. However, the retardation effect is greater at the surface, because the increase in plastic strain at the crack tip and overload plastic zone size are larger in the plane-stress surface regions than in the plane-strain interior regions. These results are not entirely consistent with either of the proposed models.

  5. Emission of PCDD/Fs and dioxin-like PCBs from metallurgy industries in S. Korea.

    Science.gov (United States)

    Yu, Byeong-Woon; Jin, Guang-Zhu; Moon, Young-Hoon; Kim, Min-Kwan; Kyoung, Jong-Dai; Chang, Yoon-Seok

    2006-01-01

    The metallurgy industry and municipal waste incinerators are considered the main sources of polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/Fs) in many countries. This study investigated the emission factors and total emissions of PCDD/Fs and dioxin-like polychlorinated biphenyls (PCBs) emitted from metallurgy industries (including ferrous and nonferrous foundries) in Korea. The toxic equivalency (TEQ) emission factor of PCDD/Fs was the highest for secondary copper production, at 24451 ng I-TEQ/ton. The total estimated emissions of PCDD/Fs from these sources were 35.259 g I-TEQ/yr, comprising 0.088 g I-TEQ/yr from ferrous foundries, 31.713 g I-TEQ/yr from copper production, 1.716 g I-TEQ/yr from lead production, 0.111 g I-TEQ/yr from zinc production, and 1.631 g I-TEQ/yr from aluminum production. The total estimated annual amounts of dioxin-like PCBs emitted from these sources were 13.260 g WHO-TEQ/yr, comprising 0.014 g WHO-TEQ/yr from ferrous foundries, 12.675 g WHO-TEQ/yr from copper production, 0.170 g WHO-TEQ/yr from lead production, 0.017 g WHO-TEQ/yr from zinc production, and 0.384 g WHO-TEQ/yr from aluminum production. The highest emission factor was found for secondary copper smelting, at 9770 ng WHO-TEQ/ton.

  6. Microstructural and mechanical characteristics of porous iron prepared by powder metallurgy.

    Science.gov (United States)

    Capek, Jaroslav; Vojtěch, Dalibor

    2014-10-01

    The demand for porous biodegradable load-bearing implants has been increasing recently. Based on investigations of biodegradable stents, porous iron may be a suitable material for such applications. In this study, we prepared porous iron samples with porosities of 34-51 vol.% by powder metallurgy using ammonium bicarbonate as a space-holder material. We studied sample microstructure (SEM-EDX and XRD), flexural and compressive behaviors (universal loading machine) and hardness HV5 (hardness tester) of the prepared samples. Sample porosity increased with the amount of spacer in the initial mixtures. Only the pore surfaces had insignificant oxidation and no other contamination was observed. Increasing porosity decreased the mechanical properties of the samples; although, the properties were still comparable with human bone and higher than those of porous non-metallic biomaterials and porous magnesium prepared in a similar way. Based on these results, powder metallurgy appears to be a suitable method for the preparation of porous iron for orthopedic applications.

  7. Fractionation study in bioleached metallurgy wastes using six-step sequential extraction.

    Science.gov (United States)

    Krasnodebska-Ostrega, Beata; Pałdyna, Joanna; Kowalska, Joanna; Jedynak, Łukasz; Golimowski, Jerzy

    2009-08-15

    The stored metallurgy wastes contain residues from ore processing operations that are characterized by relatively high concentrations of heavy metals. The bioleaching process makes use of bacteria to recover elements from industrial wastes and to decrease potential risk of environmental contamination. Wastes were treated by solutions containing bacteria. In this work, the optimized six-stage sequential extraction procedure was applied for the fractionation of Ni, Cr, Fe, Mn, Cu and Zn in iron-nickel metallurgy wastes deposited in Southern Poland (Szklary). Fractionation and total concentrations of elements in wastes before and after various bioleaching treatments were studied. Analyses of the extracts were performed by ICP-MS and FAAS. To achieve the most effective bioleaching of Zn, Cr, Ni, Cu, Mn, Fe the usage of both autotrophic and heterotrophic bacteria in sequence, combined with flushing of the residue after bioleaching is required. 80-100% of total metal concentrations were mobilized after the proposed treatment. Wastes treated according to this procedure could be deposited without any risk of environmental contamination and additionally the metals could be recovered for industrial purposes.

  8. Porous titanium scaffolds fabricated using a rapid prototyping and powder metallurgy technique.

    Science.gov (United States)

    Ryan, Garrett E; Pandit, Abhay S; Apatsidis, Dimitrios P

    2008-09-01

    One of the main issues in orthopaedic implant design is the fabrication of scaffolds that closely mimic the biomechanical properties of the surrounding bone. This research reports on a multi-stage rapid prototyping technique that was successfully developed to produce porous titanium scaffolds with fully interconnected pore networks and reproducible porosity and pore size. The scaffolds' porous characteristics were governed by a sacrificial wax template, fabricated using a commercial 3D-printer. Powder metallurgy processes were employed to generate the titanium scaffolds by filling around the wax template with titanium slurry. In the attempt to optimise the powder metallurgy technique, variations in slurry concentration, compaction pressure and sintering temperature were investigated. By altering the wax design template, pore sizes ranging from 200 to 400 microm were achieved. Scaffolds with porosities of 66.8 +/- 3.6% revealed compression strengths of 104.4+/-22.5 MPa in the axial direction and 23.5 +/- 9.6 MPa in the transverse direction demonstrating their anisotropic nature. Scaffold topography was characterised using scanning electron microscopy and microcomputed tomography. Three-dimensional reconstruction enabled the main architectural parameters such as pore size, interconnecting porosity, level of anisotropy and level of structural disorder to be determined. The titanium scaffolds were compared to their intended designs, as governed by their sacrificial wax templates. Although discrepancies in architectural parameters existed between the intended and the actual scaffolds, overall the results indicate that the porous titanium scaffolds have the properties to be potentially employed in orthopaedic applications.

  9. Microstructural and electrical investigation of Cu-Ni-Cr alloys obtained by powder metallurgy method

    Energy Technology Data Exchange (ETDEWEB)

    Carrio, Juan A.G.; Carvalhal, M.A.; Ayabe, L.M.; Monteiro, W.A., E-mail: jgcarrio@mackenzie.br [Universidade Presbiteriana Mackenzie (UPM/CCH), Sao Paulo, SP (Brazil). Centro de Ciencias e Humanidades. Dept. de Fisica; Silva, L.C.E. da; Silva Junior, R.V., E-mail: fisica.cch@mackenzie.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    The aim of this work, using the powder metallurgy process, is to synthesize metallic alloys with high mechanical strength and high electric conductivity, after melting optimizing and thermal treatments. The Cu-Ni-Cr (wt%) alloys are characterized in their mechanical and electrical properties as well as the obtained microstructure. Through the process of powder metallurgy, contacts and structural parts can be obtained. The alloys elements are added to copper with the intention to improve their strength, ductility and thermal stability, without causing considerable damages in their form, electrical and thermal conductivity, and corrosion resistance. The metallic powders were mixed for a suitable time and then they were pressed in a cold uniaxial pressing (1000 kPa). Afterwards, the specimens were sintered in temperatures varying from 700 up to 800 deg C under vacuum. At last, the samples were homogenized at 550 deg C under vacuum, for special times. The comparative analysis is based on the sintered density, densification parameter, hardness, macrostructures and microstructures of the samples. The alloys were characterized by optical microscopy, X-rays powder diffraction, electrical conductivity and Vickers hardness. (author)

  10. Acoustic harmonic generation measurement applications: Detection of tight cracks in powder metallurgy compacts

    Science.gov (United States)

    Barnard, D. J.; Foley, J. C.

    2000-05-01

    Standard linear ultrasonic testing techniques have long been employed for locating and characterizing relatively open cracks in a wide variety of materials, from metallic alloys and ceramics to composites. In all these materials, the detection of open cracks easily accomplished because the void between the two crack surfaces provides sufficient acoustic impedance mismatch to reflect the incident energy. Closed or partially closed cracks, however, may often go undetected because contacting interfaces allow transmission of ultrasound. In the green (unsintered) state, powder metallurgy compacts typically contain high residual stresses that have the ability to close cracks formed during the compaction process, a result of oxide films, improper powder lubricant, mold design, etc. After sintering, the reduction of residual stresses may no longer be sufficient to close the crack. Although the crack may be more easily detected, it is obvious most desirable to discover defects prior to sintering. It has been shown that the displacements of an interface may be highly nonlinear if a stress wave of sufficient intensity propagates across it, a result of the stress wave either opening or closing the interface. Current efforts involve the application of nonlinear acoustic techniques, in particular acoustic harmonic generation measurements, for the detection and characterization of tightly closed cracks in powder metallurgy parts. A description of the equipment and the measurement technique will be discussed and initial experimental results on sintered and green compacts will be presented.—This work was performed at the Ames Laboratory, Iowa State University under USDOE Contract No. W-7405-ENG-82.

  11. Industrial chemistry engineering

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-01-15

    This book on industrial chemistry engineering is divided in two parts. The first part deals with industrial chemistry, inorganic industrial chemistry, organic industrial chemistry, analytical chemistry and practical questions. The last parts explain the chemical industry, a unit parts and thermodynamics in chemical industry and reference. It reveals the test subjects for the industrial chemistry engineering with a written examination and practical skill.

  12. REFLECTIVE APPROACH IN TEACHING PRE-DEGREE CHEMISTRY

    Directory of Open Access Journals (Sweden)

    B. Venkateswara RAO

    2009-04-01

    Full Text Available The study is a component of a larger investigation that focuses on exemplary practice in chemistry education. This case study involves an investigation of a chemistry teacher in two years intermediate education in Vijayawada, Andhra Pradesh, India. The study utilized an interpretive methodology in which the questions emerged from intensive observations of chemistry lessons in classes taught by a teacher. The principal finding was that a teacher focused on teaching for understanding. Once teacher tended to emphasize whole-class activities while the other times he utilized more small-group and individualized activities. The teacher was successful in his goal of teaching for understanding because he was effective classroom manager and he had strong science content knowledge that enabled him to focus on instructional strategies that facilitated student understanding. He asked appropriate questions, responded to student questions, and used effective cognitive monitoring strategies. The teacher was able to teach effectively because he had adequate content knowledge and pedagogical content knowledge. Researcher adopted the method of action research to class room teaching where a classroom event triggers the process of reflection followed by critical analysis of the event which leads to change and subsequent reflection to observe that change and so on. He has taken two different texts to teach students. Out of two texts, one is explaining the metallurgy of Magnesium. In that case, he was successful as a teacher when he adopted comparative method of teaching metallurgy of Magnesium rather than the traditional method of teaching. The other one is explaining the properties of Hydrogen peroxide. In this case he was successful as a teacher by adopting discussion, interaction and discussion method.

  13. 76 FR 64344 - Amended Record of Decision for the Nuclear Facility Portion of the Chemistry and Metallurgy...

    Science.gov (United States)

    2011-10-18

    ... Excavation Option would entail excavating through the layer of poorly welded tuff at the construction site... selection of the construction option to be implemented. NNSA will select the appropriate Excavation Option... the two options (Shallow Excavation and Deep Excavation) that NNSA identified for construction of the...

  14. Physical chemistry of the powder metallurgy of beryllium: Chemical characterization of the powder in relation to its granularity

    Energy Technology Data Exchange (ETDEWEB)

    Bracconi, P.; Buisson, L. [Univ. of Burgundy, Dijon (France). Lab. for the Reactivity of Solids; Bonnet, C. [CEA, Valduc (France). Atomic Energy Board

    1996-02-01

    Combining the systematic quantitative chemical analysis of the light impurities H, C, N, and O, the quantitative thermal desorption of molecular H{sub 2}O and H{sub 2}, and X-ray diffractometry of various size fractions of a commercial Be powder (SP-65 grade from Brush-Wellman) allowed the precise determination of the mean composition and equivalent mean thickness of the surface impurity phases in the passivation-contamination layer on the surface of the particles. The overall surface stoichiometry is as follows: 0.2 BeO{sub crystallized}, 0.8 [BeO {minus} 0.59 H{sub 2}O]{sub amorphous}, 0.14 H{sub 2}O{sub ads}. The result of the elemental analysis by X-ray photoelectron spectroscopy of the unetched surface of a powder pellet is compared. Analysis of the metallic impurities reveals increased concentrations of Mg, Ca, Ti, and Cr in the finest fraction, presumably due to the liberation of fine particles of intermetallic phases by attrition

  15. Bubble and foam chemistry

    CERN Document Server

    Pugh, Robert J

    2016-01-01

    This indispensable guide will equip the reader with a thorough understanding of the field of foaming chemistry. Assuming only basic theoretical background knowledge, the book provides a straightforward introduction to the principles and properties of foams and foaming surfactants. It discusses the key ideas that underpin why foaming occurs, how it can be avoided and how different degrees of antifoaming can be achieved, and covers the latest test methods, including laboratory and industrial developed techniques. Detailing a variety of different kinds of foams, from wet detergents and food foams, to polymeric, material and metal foams, it connects theory to real-world applications and recent developments in foam research. Combining academic and industrial viewpoints, this book is the definitive stand-alone resource for researchers, students and industrialists working on foam technology, colloidal systems in the field of chemical engineering, fluid mechanics, physical chemistry, and applied physics.

  16. Industrial ecology: Environmental chemistry and hazardous waste

    Energy Technology Data Exchange (ETDEWEB)

    Manahan, S.E. [Univ. of Missouri, Columbia, MO (United States). Dept. of Chemistry

    1999-01-01

    Industrial ecology may be a relatively new concept -- yet it`s already proven instrumental for solving a wide variety of problems involving pollution and hazardous waste, especially where available material resources have been limited. By treating industrial systems in a manner that parallels ecological systems in nature, industrial ecology provides a substantial addition to the technologies of environmental chemistry. Stanley E. Manahan, bestselling author of many environmental chemistry books for Lewis Publishers, now examines Industrial Ecology: Environmental Chemistry and Hazardous Waste. His study of this innovative technology uses an overall framework of industrial ecology to cover hazardous wastes from an environmental chemistry perspective. Chapters one to seven focus on how industrial ecology relates to environmental science and technology, with consideration of the anthrosphere as one of five major environmental spheres. Subsequent chapters deal specifically with hazardous substances and hazardous waste, as they relate to industrial ecology and environmental chemistry.

  17. Computational chemistry

    Science.gov (United States)

    Arnold, J. O.

    1987-01-01

    With the advent of supercomputers, modern computational chemistry algorithms and codes, a powerful tool was created to help fill NASA's continuing need for information on the properties of matter in hostile or unusual environments. Computational resources provided under the National Aerodynamics Simulator (NAS) program were a cornerstone for recent advancements in this field. Properties of gases, materials, and their interactions can be determined from solutions of the governing equations. In the case of gases, for example, radiative transition probabilites per particle, bond-dissociation energies, and rates of simple chemical reactions can be determined computationally as reliably as from experiment. The data are proving to be quite valuable in providing inputs to real-gas flow simulation codes used to compute aerothermodynamic loads on NASA's aeroassist orbital transfer vehicles and a host of problems related to the National Aerospace Plane Program. Although more approximate, similar solutions can be obtained for ensembles of atoms simulating small particles of materials with and without the presence of gases. Computational chemistry has application in studying catalysis, properties of polymers, all of interest to various NASA missions, including those previously mentioned. In addition to discussing these applications of computational chemistry within NASA, the governing equations and the need for supercomputers for their solution is outlined.

  18. Analytical chemistry under the impact of modern science and technology and its philosophical thought%现代科技冲击下的分析化学及哲学思考

    Institute of Scientific and Technical Information of China (English)

    赖国松; 张海丽

    2013-01-01

    Conventional analytical chemistry is a second discipline tasking in determination and characterizing mainly in the field of chemistry .With the development of modern science and technology , analytical chemistry has absorbed and combined some fresh knowledge of some related disciplines such as physics , biology , material and informational science , which resulted in the great enhancement of the level of discipline intercross and the enlargement of discipline foundation and research fields . The analytical method also transformed from the chemical analysis mainly by hand to the instrumental analysis .However, its possible negative influence to the human being and society of analytical chemistry should be properly thought about when it plays more and more important roles in the modern society among with its fast development .%传统的分析化学是一门在化学领域以测量和表征为主要任务的二级学科。伴随着现代科技的进步,分析化学不断吸纳和结合包括物理、生物、材料、信息学科在内的其它相关学科的最新成果,学科交叉程度越来越高,学科基础和研究领域不断拓展,研究手段也实现了以人工的化学分析为主到以仪器分析为主的重大转变。然而,随着分析化学的不断发展,分析化学在现代社会中发挥着越来越重要作用的同时,对人类社会可能造成的安全、伦理道德等方面的影响也不容忽视。

  19. Understanding Academic Performance in Organic Chemistry

    Science.gov (United States)

    Szu, Evan; Nandagopal, Kiruthiga; Shavelson, Richard J.; Lopez, Enrique J.; Penn, John H.; Scharberg, Maureen; Hill, Geannine W.

    2011-01-01

    Successful completion of organic chemistry is a prerequisite for many graduate and professional programs in science, technology, engineering, and mathematics, yet the failure rate for this sequence of courses is notoriously high. To date, few studies have examined why some students succeed while others have difficulty in organic chemistry. This…

  20. Understanding Academic Performance in Organic Chemistry

    Science.gov (United States)

    Szu, Evan; Nandagopal, Kiruthiga; Shavelson, Richard J.; Lopez, Enrique J.; Penn, John H.; Scharberg, Maureen; Hill, Geannine W.

    2011-01-01

    Successful completion of organic chemistry is a prerequisite for many graduate and professional programs in science, technology, engineering, and mathematics, yet the failure rate for this sequence of courses is notoriously high. To date, few studies have examined why some students succeed while others have difficulty in organic chemistry. This…

  1. Theoretical chemistry periodicities in chemistry and biology

    CERN Document Server

    Eyring, Henry

    1978-01-01

    Theoretical Chemistry: Periodicities in Chemistry and Biology, Volume 4 covers the aspects of theoretical chemistry. The book discusses the stably rotating patterns of reaction and diffusion; the chemistry of inorganic systems exhibiting nonmonotonic behavior; and population cycles. The text also describes the mathematical modeling of excitable media in neurobiology and chemistry; oscillating enzyme reactions; and oscillatory properties and excitability of the heart cell membrane. Selected topics from the theory of physico-chemical instabilities are also encompassed. Chemists, mechanical engin

  2. Practical Metallurgy

    DEFF Research Database (Denmark)

    Bissacco, Giuliano; Deganello, Davide

    2003-01-01

    This is the report regards the activities carried out during the practical metatllurgy course concerning material properties and structures and their testing & analysis methods. During the course several aspects of the materials have been considered and different techniques have been analyzed....

  3. Surface chemistry

    CERN Document Server

    Desai, KR

    2008-01-01

    The surface Chemistry of a material as a whole is crucially dependent upon the Nature and type of surfaces exposed on crystallites. It is therefore vitally important to independently Study different, well - defined surfaces through surface analytical techniques. In addition to composition and structure of surface, the subject also provides information on dynamic light scattering, micro emulsions, colloid Stability control and nanostructures. The present book endeavour to bring before the reader that the understanding and exploitation of Solid state phenomena depended largely on the ability to

  4. Laser ablation in analytical chemistry.

    Science.gov (United States)

    Russo, Richard E; Mao, Xianglei; Gonzalez, Jhanis J; Zorba, Vassilia; Yoo, Jong

    2013-07-02

    In 2002, we wrote an Analytical Chemistry feature article describing the Physics of Laser Ablation in Microchemical Analysis. In line with the theme of the 2002 article, this manuscript discusses current issues in fundamental research, applications based on detecting photons at the ablation site (LIBS and LAMIS) and by collecting particles for excitation in a secondary source (ICP), and directions for the technology.

  5. The aqueous chemistry of oxides

    CERN Document Server

    Bunker, Bruce C

    2016-01-01

    The Aqueous Chemistry of Oxides is a comprehensive reference volume and special topics textbook that explores all of the major chemical reactions that take place between oxides and aqueous solutions. The book highlights the enormous impact that oxide-water reactions have in advanced technologies, materials science, geochemistry, and environmental science.

  6. USING GREEN CHEMISTRY TO INFLUENCE PROCESS DEVELOPMENT

    Science.gov (United States)

    The twelve principles of green chemistry by Anastas and Warner provide the researcher with a foundation or pathway which allows opportunities to incorporate greenness into an existing reaction or when developing alternative technologies. The twelve additional principles of green ...

  7. Report: Analytical Chemistry in a Changing World.

    Science.gov (United States)

    Laitinen, H. A.

    1980-01-01

    Examines some of the changes that have occurred in the field of analytic chemistry, with emphasis on how the field has adapted to changes in science and technology. Current trends also are identified and discussed. (CS)

  8. Quasicrystal discovery bags 2011 chemistry Nobel

    Science.gov (United States)

    Banks, Michael

    2011-11-01

    The 2011 Nobel Prize for Chemistry has been awarded to Daniel Shechtman from Technion - Israel institute of Technology for his discovery of quasicrystals, which are materials that have ordered but not periodic structures.

  9. Presidential Green Chemistry Challenge: 2004 Greener Reaction Conditions Award

    Science.gov (United States)

    Presidential Green Chemistry Challenge 2004 award winner, Buckman Laboratories International, developed Optimyze technology, which uses an esterase enzyme to remove sticky contaminants from paper products prior to recycling.

  10. Presidential Green Chemistry Challenge: 2007 Greener Reaction Conditions Award

    Science.gov (United States)

    Presidential Green Chemistry Challenge 2007 award winner, Headwaters Technology Innovation, developed a metal nanocatalyst to synthesize hydrogen peroxide directly from hydrogen and oxygen, eliminating hazardous chemicals.

  11. Microstructural Characterization and Mechanical Properties of Powder Metallurgy Dual Phase Steel Preforms

    Institute of Scientific and Technical Information of China (English)

    K. Mahesh; S. Sankaran; P. Venugopal

    2012-01-01

    In order to improve the mechanical properties of powder metallurgy (P/M) ferrite-pearlite steel, a dual phase (DP) ferrite-martensite steel was produced through intercritical annealing of sintered P/M preforms. Mi-crostructures of the sintered and DP steels were examined with optical, scanning and transmission electron microscopes. Mechanical properties were evaluated through hardness measurements and compression tests. Microstructural studies revealed that sintered steel contained polygonal ferrite-pearlite while the DP steel contained polygonal, lath and acicular ferrite along with lath-type martensite as microstructural constituents. In DP steels, with increasing mean preform density, the microstructure contained fine and continuous network of martensite colonies with minimum porosity. The work hardening rate vs plastic strain plots (Jaoul-Crussard analysis) of both the steels revealed typical three stage deformation behaviour for low and high mean preform densities. Compression tests revealed that, DP P/M steel displayed higher strength-plasticity combination than the sintered steel.

  12. Structure of Grading a Resistor-Heated System of Warm Compaction in Powder Metallurgy

    Institute of Scientific and Technical Information of China (English)

    LIU Hua; SHAO Ming; CHEN Wei-ping; ZHU Quan-li; LI Yuan-yuan

    2005-01-01

    We present the scheme of the structure of grading a resistor-heated system of warm compaction in powder metallurgy. The structure has the first heater and the second heater that are heated by electrical tubes. Powder is heated in turn in the first heater and the second heater, where there is the mass fluidity of powder under gravity. The dimensions of the first heater and the second heater were calculated from the Fourier equation of heat conduction, and the boundary condition was constant temperature. The drawings of the first heater, the second heater and the powder-delivering device were given. The structure of the heat equipment is simple and easy to manufacture. Finally, an exact warm compaction press system HGWY-Ⅱ was developed for the heating system.

  13. Accelerated Threshold Fatigue Crack Growth Effect-Powder Metallurgy Aluminum Alloy

    Science.gov (United States)

    Piascik, R. S.; Newman, J. A.

    2002-01-01

    Fatigue crack growth (FCG) research conducted in the near threshold regime has identified a room temperature creep crack growth damage mechanism for a fine grain powder metallurgy (PM) aluminum alloy (8009). At very low (Delta) K, an abrupt acceleration in room temperature FCG rate occurs at high stress ratio (R = K(sub min)/K(sub max)). The near threshold accelerated FCG rates are exacerbated by increased levels of K(sub max) (K(sub max) = 0.4 K(sub IC)). Detailed fractographic analysis correlates accelerated FCG with the formation of crack-tip process zone micro-void damage. Experimental results show that the near threshold and K(sub max) influenced accelerated crack growth is time and temperature dependent.

  14. Friction Wear Property of Brake Materials by Copper-based Powder Metallurgy With Various Brake Speeds

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-xiu; GAO Hong-xia; WEI Xiu-lan

    2004-01-01

    The experiment is conducted on MM-1000 friction test machine, which tests friction wear property of copper-based brake materials by powder metallurgy at different brake speeds. It shows that the coefficient of friction and wear volume are greatly influenced by brake speed. When the brake speed is 4000 r/min, which is a bit higher, the material still has a higher coefficient of friction with 0.47. When the brake speed is over 4000r/min, the coefficient of friction decreased rapidly. When the brake speed is 3000r/min, the material's wear is in its minimum. That is to say no matter how higher or lower the brake speed is the wear volume is bigger relatively. With the brake speed of the lower one it mainly refers to fatigue wear; while of higher one it mainly refers to abradant and oxidation wear.

  15. A powder metallurgy austenitic stainless steel for application at very low temperatures

    CERN Document Server

    Sgobba, Stefano; Liimatainen, J; Kumpula, M

    2000-01-01

    The Large Hadron Collider to be built at CERN will require 1232 superconducting dipole magnets operating at 1.9 K. By virtue of their mechanical properties, weldability and improved austenite stability, nitrogen enriched austenitic stainless steels have been chosen as the material for several of the structural components of these magnets. Powder Metallurgy (PM) could represent an attractive production technique for components of complex shape for which dimension tolerances, dimensional stability, weldability are key issues during fabrication, and mechanical properties, ductility and leak tightness have to be guaranteed during operation. PM Hot Isostatic Pressed test plates and prototype components of 316LN-type grade have been produced by Santasalo Powdermet Oy. They have been fully characterized and mechanically tested down to 4.2 K at CERN. The fine grained structure, the absence of residual stresses, the full isotropy of mechanical properties associated to the low level of Prior Particle Boundaries oxides ...

  16. Microstructure and mechanical behavior of 6061Al reinforced with silicon nitride particles, processed by powder metallurgy

    Energy Technology Data Exchange (ETDEWEB)

    Amigo, V.; Ortiz, J.L.; Salvador, M.D.

    2000-01-31

    A critical step in the processing of Metal Matrix Composites (MMCs) reinforced with ceramic particles is the insertion of these particles into the metal matrix alloy. This greatly influences the strength of the composite since it is controlled by the metal-particle interfacial bond strength. Because of the difficulty in wetting ceramic particles with molten metal, the Powder Metallurgy or PM route was developed. Powder Extrusion consolidates the composite to over 98% dense, and can be carried out below the Solidus Temperature of the alloy. The most important aspect of the microstructure is the distribution of the reinforcing particles, and this depends on the processing and fabrication routes involved, as well as the relative size of the matrix and reinforcing particles. Extrusion can homogenize the structure to some extent, but minimizing reinforcement inhomogeneity during initial processing is important to achieve optimum properties.

  17. Effects of fine porosity on the fatigue behavior of a powder metallurgy superalloy

    Science.gov (United States)

    Miner, R. V.; Dreshfield, R. L.

    1980-01-01

    Hot-isostatically-pressed powder-metallurgy Astroloy was obtained which contained 1.4 percent porosity at the grain boundaries produced by argon entering the powder container during pressing. This material was tested at 650 C in fatigue, creep-fatigue, tension, and stress-rupture and the results compared with data on sound Astroloy. They influenced fatigue crack initiation and produced a more intergranular mode of propagation but fatigue life was not drastically reduced. Fatigue behavior of the porous material showed typical correlation with tensile behavior. The plastic strain range-life relation was reduced proportionately with the reduction in tensile ductility, but the elastic strain range-life relation was changed little.

  18. [Evaluation and prognosis of occupational risk in workers of nonferrous metallurgy enterprises].

    Science.gov (United States)

    Shliapnikov, D M; Kostarev, V G

    2014-01-01

    The article deals with results of a priori and a posteriori evaluation of occupational risk for workers' health. Categories of a priori occupational risk for workers are estimated as high to very high (intolerable) risk. Findings are that work conditions in nonferrous metallurgy workshop result in upper respiratory tract diseases (medium degree of occupational conditionality). Increased prevalence of such diseases among the workers is connected with length of service. The authors revealed priority factors for occupationally conditioned diseases. A promising approach in occupational medicine is creation of methods to evaluate and forecast occupational risk, that enable to specify goal parameters for prophylactic measures. For example, modelling the risk of occupationally conditioned diseases via changes in exposure to occupational factor and length of service proved that decrease of chemical concentrations in air of workplace to maximally allowable ones lowers risk of respiratory diseases from 14 to 6 cases per year, for length of service of 5 years and population risk.

  19. Separating and recycling metals from mixed metallic particles of crushed electronic wastes by vacuum metallurgy.

    Science.gov (United States)

    Zhan, Lu; Xu, Zhenming

    2009-09-15

    During the treatment of electronic wastes, a crushing process is usually used to strip metals from various base plates. Several methods have been applied to separate metals from nonmetals. However, mixed metallic particles obtained from these processes are still a mixture of various metals, including some toxic heavy metals such as lead and cadmium. With emphasis on recovering copper and other precious metals, there have hitherto been no satisfactory methods to recover these toxic metals. In this paper, the criterion of separating metals from mixed metallic particles by vacuum metallurgy is built. The results show that the metals with high vapor pressure have been almost recovered completely, leading to a considerable reduction of environmental pollution. In addition, the purity of copper in mixed particles has been improved from about 80 wt % to over 98 wt %.

  20. Microstructure and microanalysis studies of copper-nickel-tin alloys obtained by conventional powder metallurgy processing

    Energy Technology Data Exchange (ETDEWEB)

    Monteiro, Waldemar A.; Carrio, Juan A.G.; Masson, T.J.; Vitor, E.; Abreu, C.D.; Marques, I.M., E-mail: fisica.cch@mackenzie.br [Universidade Presbiteriana Mackenzie (CCH), Sao Paulo, SP (Brazil). Centro de Ciencias e Humanidades; Silva, L.C.E. da, E-mail: jgcarrio@mackenzie.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    The aim of this paper was to analyze the microstructural development in samples of Cu-Ni-Sn alloys (weight %) obtained by powder metallurgy (P/M). The powders were mixed for 1/2 hour. After this, they were pressed, in a cold uniaxial pressing (1000 kPa). In the next step the specimens were sintered at temperatures varying from 650 up to 780 deg C under vacuum. Secondly, the samples were homogenized at 500 deg C for several special times. The alloys were characterized by optical microscopy, electrical conductivity and Vickers hardness. X-rays powder diffraction data were collected for the sintered samples in order to a structural and microstructural analysis. The comparative analysis is based on the sintered density, densification parameter, hardness, macrostructures and microstructures of the samples. (author)

  1. Modeling of wear behavior of Al/B{sub 4}C composites produced by powder metallurgy

    Energy Technology Data Exchange (ETDEWEB)

    Sahin, Ismail; Bektas, Asli [Gazi Univ., Ankara (Turkey). Dept. of Industrial Design Engineering; Guel, Ferhat; Cinci, Hanifi [Gazi Univ., Ankara (Turkey). Dept. of Materials and Metallurgy Engineering

    2017-06-01

    Wear characteristics of composites, Al matrix reinforced with B{sub 4}C particles percentages of 5, 10,15 and 20 produced by the powder metallurgy method were studied in this study. For this purpose, a mixture of Al and B{sub 4}C powders were pressed under 650 MPa pressure and then sintered at 635 C. The analysis of hardness, density and microstructure was performed. The produced samples were worn using a pin-on-disk abrasion device under 10, 20 and 30 N load through 500, 800 and 1200 mesh SiC abrasive papers. The obtained wear values were implemented in an artificial neural network (ANN) model having three inputs and one output using feed forward backpropagation Levenberg-Marquardt algorithm. Thus, the optimum wear conditions and hardness values were determined.

  2. [The organization of the comprehensive prevention of urolithiasis among ferrous metallurgy workers].

    Science.gov (United States)

    Egorova, A M

    2009-01-01

    The purpose of study is to evaluate the effectiveness of the set of preventive measures as applied to 321 workers of basic ferrous metallurgy specialties (steel makers, mill men, hot metal shearers). During the clinical examination all the workers were divided on three groups: the workers without any pathology (11.83%, the first group), the workers with metabolic disorders only without urolitiasis (64.81%, the second group) and the workers with urolitiasis diagnosis approved by ultrasonography (23.36%, the third group). The effectiveness of rehabilitation measures was evaluated during half a year (diet therapy, drinking regimen, medicinal plants treatment). After the course of preventive measures was applied the overall health condition of most workers ameliorated and the number of workers with urolitiasis development risk factors reliably decreased up to 6-12%.

  3. Martensitic transformation of Ti50Ni30Cu20 alloy prepared by powder metallurgy

    Energy Technology Data Exchange (ETDEWEB)

    Valeanu, M., E-mail: valeanu@infim.ro [National Institute of Materials Physics, 077125 Bucharest (Romania); Lucaci, M. [National Institute for Electrical Engineering ICPE-CA, 030138 Bucharest (Romania); Crisan, A.D.; Sofronie, M. [National Institute of Materials Physics, 077125 Bucharest (Romania); Leonat, L. [National Institute for Electrical Engineering ICPE-CA, 030138 Bucharest (Romania); Kuncser, V. [National Institute of Materials Physics, 077125 Bucharest (Romania)

    2011-03-31

    Research highlights: > Martensitic transformation sequence in Ti50Ni30Cu20 prepared high - energy milling. > Two transformations (B2-B19, B2-B19') are evidenced after 10 hours of milling. > B2-B19 transformation is not more observed after 20 hours of milling. > A longer milling process promotes the formation of the secondary Ti{sub 2}(NiCu) phase. - Abstract: Phase transformation behavior of Ti50Ni30Cu20 shape memory alloys prepared by powder metallurgy is analyzed with respect to the duration of mechanical alloying. The processed blends were studied by differential scanning calorimetry and room temperature X-ray diffraction. The martensitic transformations evidenced by thermal scans are discussed in correlation with the relative phase content obtained from the refinement of the X-ray diffraction patterns.

  4. Study on Microstructures and Properties of Porous TiC Ceramics Fabricated by Powder Metallurgy

    Science.gov (United States)

    Ma, Yana; Bao, Chonggao; Han, Longhao; Chen, Jie

    2017-01-01

    Powder metallurgy process was used to fabricate porous titanium carbide (TiC) ceramics, in which TiC powders were taken as the raw materials, nickel was used as the metallic binder and urea was the space-holder. Microstructure, composition and phase of porous TiC ceramics were characterized by scanning electron microscopy (SEM) and x-ray diffraction (XRD). Flexure strength of the porous TiC ceramics was tested by a three-point bending method. The results show that macropores and micropores coexist in the prepared porous TiC ceramics. Moreover, the pore number, size and distribution in porous TiC ceramics can be controlled on demand. Particularly, the factors such as the number or size of space-holder, compacting pressure and Ni content have significant effect on the porosity and flexure strength.

  5. Warm compaction of Al2O3 particulate reinforced powder metallurgy iron-base composite

    Institute of Scientific and Technical Information of China (English)

    倪东惠; 陈维平; 肖志瑜; 邵明; 张双益

    2002-01-01

    Mechanical properties of the warm compacted alumina particulate reinforced powder metallurgy composite materials was compared with those of the materials obtained by conventional cold compaction. Factors affecting the properties of the warm compacted material such as compaction temperature, lubricant content and alumina content were studied. A 3%(mass fraction) alumina particulate reinforced iron-base composite with a green density of 7.0g/cm3 can be obtained by pressing the powder with a pressure of 700MPa at 175℃. The sintered materials have a density of 6.88g/cm3, a tensile strength of 512MPa and an elongation of 1.3%. Results show that as alumina content increases, density and mechanical properties of the composite decrease.

  6. Microstructure, mechanical behavior and biocompatibility of powder metallurgy Nb-Ti-Ta alloys as biomedical material.

    Science.gov (United States)

    Liu, Jue; Chang, Lin; Liu, Hairong; Li, Yongsheng; Yang, Hailin; Ruan, Jianming

    2017-02-01

    Microstructures, mechanical properties, apatite-forming ability and in vitro experiments were studied for Nb-25Ti-xTa (x=10, 15, 20, 25, 35at.%) alloys fabricated by powder metallurgy. It is confirmed that the alloys could achieve a relative density over 80%. Meanwhile, the increase in Ta content enhances the tensile strength, elastic modulus and hardness of the as-sintered alloys. When increasing the sintering temperatures, the microstructure became more homogeneous for β phase, resulting in a decrease in the modulus and strength. Moreover, the alloys showed a good biocompatibility due to the absence of cytotoxic elements, and were suitable for apatite formation and cell adhesion. In conclusion, Nb-25Ti-xTa alloys are potentially useful in biomedical applications with their mechanical and biological properties being evaluated in this work. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Electron beam technology for multipollutant emissions control from heavy fuel oil-fired boiler.

    Science.gov (United States)

    Chmielewski, Andrzej G; Ostapczuk, Anna; Licki, Janusz

    2010-08-01

    The electron beam treatment technology for purification of exhaust gases from the burning of heavy fuel oil (HFO) mazout with sulfur content approximately 3 wt % was tested at the Institute of Nuclear Chemistry and Technology laboratory plant. The parametric study was conducted to determine the sulfur dioxide (SO2), oxides of nitrogen (NO(x)), and polycyclic aromatic hydrocarbon (PAH) removal efficiency as a function of temperature and humidity of irradiated gases, absorbed irradiation dose, and ammonia stoichiometry process parameters. In the test performed under optimal conditions with an irradiation dose of 12.4 kGy, simultaneous removal efficiencies of approximately 98% for SO2, and 80% for NO(x) were recorded. The simultaneous decrease of PAH and one-ringed aromatic hydrocarbon (benzene, toluene, and xylenes [BTX]) concentrations was observed in the irradiated flue gas. Overall removal efficiencies of approximately 42% for PAHs and 86% for BTXs were achieved with an irradiation dose 5.3 kGy. The decomposition ratio of these compounds increased with an increase of absorbed dose. The decrease of PAH and BTX concentrations was followed by the increase of oxygen-containing aromatic hydrocarbon concentrations. The PAH and BTX decomposition process was initialized through the reaction with hydroxyl radicals that formed in the electron beam irradiated flue gas. Their decomposition process is based on similar principles as the primary reaction concerning SO2 and NO(x) removal; that is, free radicals attack organic compound chains or rings, causing volatile organic compound decomposition. Thus, the electron beam flue gas treatment (EBFGT) technology ensures simultaneous removal of acid (SO2 and NO(x)) and organic (PAH and BTX) pollutants from flue gas emitted from burning of HFO. This technology is a multipollutant emission control technology that can be applied for treatment of flue gas emitted from coal-, lignite-, and HFO-fired boilers. Other thermal processes such

  8. Assessment of Low Cycle Fatigue Behavior of Powder Metallurgy Alloy U720

    Science.gov (United States)

    Gabb, Tomothy P.; Bonacuse, Peter J.; Ghosn, Louis J.; Sweeney, Joseph W.; Chatterjee, Amit; Green, Kenneth A.

    2000-01-01

    The fatigue lives of modem powder metallurgy disk alloys are influenced by variabilities in alloy microstructure and mechanical properties. These properties can vary as functions of variables the different steps of materials/component processing: powder atomization, consolidation, extrusion, forging, heat treating, and machining. It is important to understand the relationship between the statistical variations in life and these variables, as well as the change in life distribution due to changes in fatigue loading conditions. The objective of this study was to investigate these relationships in a nickel-base disk superalloy, U720, produced using powder metallurgy processing. Multiple strain-controlled fatigue tests were performed at 538 C (1000 F) at limited sets of test conditions. Analyses were performed to: (1) assess variations of microstructure, mechanical properties, and LCF failure initiation sites as functions of disk processing and loading conditions; and (2) compare mean and minimum fatigue life predictions using different approaches for modeling the data from assorted test conditions. Significant variations in life were observed as functions of the disk processing variables evaluated. However, the lives of all specimens could still be combined and modeled together. The failure initiation sites for tests performed at a strain ratio R(sub epsilon) = epsilon(sub min)/epsilon(sub max) of 0 were different from those in tests at a strain ratio of -1. An approach could still be applied to account for the differences in mean and maximum stresses and strains. This allowed the data in tests of various conditions to be combined for more robust statistical estimates of mean and minimum lives.

  9. Humanizing Chemistry Education: From Simple Contextualization to Multifaceted Problematization

    Science.gov (United States)

    Sjöström, Jesper; Talanquer, Vicente

    2014-01-01

    Chemistry teaching has traditionally been weakly connected to everyday life, technology, society, and history and philosophy of science. This article highlights knowledge areas and perspectives needed by the humanistic (and critical-reflexive) chemistry teacher. Different humanistic approaches in chemistry teaching, from simple contextualization…

  10. Humanizing Chemistry Education: From Simple Contextualization to Multifaceted Problematization

    Science.gov (United States)

    Sjöström, Jesper; Talanquer, Vicente

    2014-01-01

    Chemistry teaching has traditionally been weakly connected to everyday life, technology, society, and history and philosophy of science. This article highlights knowledge areas and perspectives needed by the humanistic (and critical-reflexive) chemistry teacher. Different humanistic approaches in chemistry teaching, from simple contextualization…

  11. Technology.

    Science.gov (United States)

    Online-Offline, 1998

    1998-01-01

    Focuses on technology, on advances in such areas as aeronautics, electronics, physics, the space sciences, as well as computers and the attendant progress in medicine, robotics, and artificial intelligence. Describes educational resources for elementary and middle school students, including Web sites, CD-ROMs and software, videotapes, books,…

  12. Why Teach Environmental Chemistry?

    Science.gov (United States)

    Gardner, Marjorie H.

    1974-01-01

    Discusses the importance of teaching environmental chemistry in secondary school science classes, and outlines five examples of environmental chemistry problems that focus on major concepts of chemistry and have critical implications for human survival and well-being. (JR)

  13. Science Update: Inorganic Chemistry

    Science.gov (United States)

    Rawls, Rebecca

    1978-01-01

    This first in a series of articles describing the state of the art of various branches of chemistry reviews inorganic chemistry, including bioinorganic, photochemistry, organometallic, and solid state chemistries. (SL)

  14. “化学分析技术”一体化教学模式改革探索%Research on the reform of integration of teaching in Analytical Technologies of Chemistry

    Institute of Scientific and Technical Information of China (English)

    李秋; 唐国钢

    2014-01-01

    With the development of technology and the progress of society,it has been increasingly difficult for the current teaching content and methods for current analytical technologies of chemistry course to meet the demands of the society for college students' training.In order to improve the quality of teaching,the course content system of analytical technologies of chemistry course in higher vocational college was established,with the demand of enterprise's post for knowledge,practical skills and quality as the teaching goal.In terms of integration of teaching, cearnirg and doing model,this paper primarily discusses the teaching reform from teaching content,teaching meth-ods and assessment methods to stimulate students' creative motivation and improve students' skills.%当前“化学分析技术”课程的教学内容和方法难以满足社会对大学生职业素质的要求。为提高教学质量,通过赴企业调研、专门商讨等形式重新构建高职高专“化学分析技术”课程内容体系,把企业岗位对课程知识、实践技能和素质的需要作为教学目标。采用“教学做一体化”模式,从教学内容、教学方法和考核方式等方面进行改革,激发学生的创新学习动力,培养学生的实践能力。

  15. Environmental chemistry. Seventh edition

    Energy Technology Data Exchange (ETDEWEB)

    Manahan, S.E. [Univ. of Missouri, Columbia, MO (United States)

    1999-11-01

    This book presents a basic understanding of environmental chemistry and its applications. In addition to providing updated materials in this field, the book emphasizes the major concepts essential to the practice of environmental chemistry. Topics of discussion include the following: toxicological chemistry; toxicological chemistry of chemical substances; chemical analysis of water and wastewater; chemical analysis of wastes and solids; air and gas analysis; chemical analysis of biological materials and xenobiotics; fundamentals of chemistry; and fundamentals of organic chemistry.

  16. Combustion chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Brown, N.J. [Lawrence Berkeley Laboratory, CA (United States)

    1993-12-01

    This research is concerned with the development and use of sensitivity analysis tools to probe the response of dependent variables to model input variables. Sensitivity analysis is important at all levels of combustion modeling. This group`s research continues to be focused on elucidating the interrelationship between features in the underlying potential energy surface (obtained from ab initio quantum chemistry calculations) and their responses in the quantum dynamics, e.g., reactive transition probabilities, cross sections, and thermal rate coefficients. The goals of this research are: (i) to provide feedback information to quantum chemists in their potential surface refinement efforts, and (ii) to gain a better understanding of how various regions in the potential influence the dynamics. These investigations are carried out with the methodology of quantum functional sensitivity analysis (QFSA).

  17. Astronomical chemistry.

    Science.gov (United States)

    Klemperer, William

    2011-01-01

    The discovery of polar polyatomic molecules in higher-density regions of the interstellar medium by means of their rotational emission detected by radioastronomy has changed our conception of the universe from essentially atomic to highly molecular. We discuss models for molecule formation, emphasizing the general lack of thermodynamic equilibrium. Detailed chemical kinetics is needed to understand molecule formation as well as destruction. Ion molecule reactions appear to be an important class for the generally low temperatures of the interstellar medium. The need for the intrinsically high-quality factor of rotational transitions to definitively pin down molecular emitters has been well established by radioastronomy. The observation of abundant molecular ions both positive and, as recently observed, negative provides benchmarks for chemical kinetic schemes. Of considerable importance in guiding our understanding of astronomical chemistry is the fact that the larger molecules (with more than five atoms) are all organic.

  18. Science Update: Inorganic Chemistry.

    Science.gov (United States)

    Rawls, Rebecca

    1981-01-01

    Describes areas of inorganic chemistry which have changed dramatically in the past year or two, including photochemistry, electrochemistry, organometallic complexes, inorganic reaction theory, and solid state chemistry. (DS)

  19. Advanced Chemistry Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Description/History: Chemistry laboratory The Advanced Chemistry Laboratory (ACL) is a unique facility designed for working with the most super toxic compounds known...

  20. Some electroanalytical investigations into the cure chemistry of industrial sealants

    OpenAIRE

    Raftery, Declan Patrick

    1996-01-01

    This thesis represents a study of the cure chemistry of three contrasting adhesive technologies, applying a range of analytical approaches to gain further insight into the complex chemistry of adhesives. An introduction is given in chapter one into the general chemistry of adhesives and their analysis, with particular emphasis on anaerobic adhesives and the crucial role played by transition metals in the cure chemistry. In order to elucidate the role played by tertiary amines and saccahri...

  1. A methodological proposal to study the prehistorical metallurgy: the case of Gorny in the Kargaly Region (Orenburg, Russia

    Directory of Open Access Journals (Sweden)

    Rovira, Salvador

    1999-12-01

    Full Text Available Archaeological field-work realised at the site of Gorny (occupied from 1700 to 1400 BC has furnished an important collection of materials related to metallurgical activities (ores, slags, by-products and copper objects. These have been analyzed by a variety of instrumental techniques (scanning electron microscopy, X-ray fluorescence spectroscopy and metallography. The results show that metallurgy was a primitive one that worked oxidised copper ores by a non-slagging smelting process. Cast objects were finished by cold hammering and, on some occasions, annealing. A replication of the prehistoric technology has been achieved by means of on-site smelting experiments. Thus, economic variables such as the efficiency of copper recovery and charcoal consumption have been evaluated and, using them, theoretical models of copper production and its behavioural impact have been constructed.

    Los trabajos arqueológicos de campo en el sitio de Gorny (habitado durante los siglos XVII-XV AC han proporcionado una importante colección de materiales relacionados con actividades metalúrgicas (minerales, escorias, restos de fundición y objetos metálicos. En su estudio analítico se han empleado diversas técnicas de laboratorio (microscopía electrónica de barrido, espectrometría por fluorescencia de rayos x, metalografía cuyos resultados caracterizan una metalurgia de rasgos primitivos que parte de la fundición directa de minerales oxídicos de cobre. Los objetos de metal, fundidos en molde, eran terminados mediante trabajos de forja y aplicación, en ocasiones, de tratamientos térmicos. Con la ayuda de experimentos de fundición in situ se ha reproducido el proceso prehistórico, permitiendo de ese modo establecer variables económicas tales como el rendimiento en cobre de las fundiciones y el consumo de combustible, a partir de las cuales se elaboran modelos teóricos estimativos de la producción metalúrgica y su impacto en el medio

  2. Medicinal electrochemistry: integration of electrochemistry, medicinal chemistry and computational chemistry.

    Science.gov (United States)

    Almeida, M O; Maltarollo, V G; de Toledo, R A; Shim, H; Santos, M C; Honorio, K M

    2014-01-01

    Over the last centuries, there were many important discoveries in medicine that were crucial for gaining a better understanding of several physiological processes. Molecular modelling techniques are powerful tools that have been successfully used to analyse and interface medicinal chemistry studies with electrochemical experimental results. This special combination can help to comprehend medicinal chemistry problems, such as predicting biological activity and understanding drug action mechanisms. Electrochemistry has provided better comprehension of biological reactions and, as a result of many technological improvements, the combination of electrochemical techniques and biosensors has become an appealing choice for pharmaceutical and biomedical analyses. Therefore, this review will briefly outline the present scope and future advances related to the integration of electrochemical and medicinal chemistry approaches based on various applications from recent studies.

  3. Technology

    Directory of Open Access Journals (Sweden)

    Xu Jing

    2016-01-01

    Full Text Available The traditional answer card reading method using OMR (Optical Mark Reader, most commonly, OMR special card special use, less versatile, high cost, aiming at the existing problems proposed a method based on pattern recognition of the answer card identification method. Using the method based on Line Segment Detector to detect the tilt of the image, the existence of tilt image rotation correction, and eventually achieve positioning and detection of answers to the answer sheet .Pattern recognition technology for automatic reading, high accuracy, detect faster

  4. A method to rapidly determine the sintering process parameters of powder metallurgy by real-time resistivity monitoring

    Science.gov (United States)

    Xiao, Zhen; Liu, Huanchao; Geng, Haoran; Leng, Jinfeng

    2016-10-01

    A new method, which is called the resistivity method, is applied in this paper to explore the optimum sintering parameters of powder metallurgy (PM) since general methods are always labor-intensive and time-consuming. This method can probe the resistivity of the powder metallurgy samples in real-time during the sintering process, to quickly estimate the change of the relative density, which consequently determine the properties of the sintered item. As an example, in this paper, copper/tungsten carbide (Cu/WC) composites and pure aluminum (Al) powder compacts are experimentally considered. As a result, for the Cu/WC composites, the highest value of relative density appeared at the holding time of 50 min where the sample has the lowest resistivity. For the Al compacts, the optimum sintering temperature is 450 °C, and the longer the holding time the better.

  5. Thermodynamic study and modelling of iron-based melts for adequate prediction of modern ladle metallurgy processes

    Science.gov (United States)

    Zaitsev, A. I.; Rodionova, I. G.; Shaposhnikov, N. G.; Zemlyanko, O. A.; Karamisheva, N. A.

    2008-02-01

    The representation of iron-based melts as associated liquids have been developed basing on the detail experimental investigation and analysis of available data on their thermodynamic properties and phase equilibria. It has allowed, for the first time, to interpret adequately the reactivity of the earth metals in the iron-based melts and to predict with high precision the reactions of metal refinement and non-metallic inclusions modifying in modern ladle metallurgy.

  6. [Factors of working environment and process on non-ferrous metallurgy enterprises in Bashkortostan Republic and workers' occupational health].

    Science.gov (United States)

    Bakirov, A B; Takaev, R M; Kondrova, N S; Shaĭkhlislamova, E R

    2011-01-01

    The authors studied factors of working environment and process on nonferrous metallurgy enterprises in Bashkortostan Republic and evaluated their influence on the workers' occupational health over 1997-2009, with consideration of occupation, sex, age, length of service, work conditions and characters. The article demonstrates that sanitary and hygienic characteristics of occupations connected with machinery operation are prone to increased integral evaluation of work conditions due to underestimation of actual hardiness and intensity of work.

  7. A study of the efficiency of spur gears made of powder metallurgy materials - ground versus super-finished surfaces

    OpenAIRE

    Li, Xinmin; Sosa, Mario; Andersson, Martin; Olofsson, Ulf

    2016-01-01

    Power loss is one of the main concerns in gear transmission systems. In this study a recirculating power back-to-back FZG test rig was used to investigate the efficiency of spur gears made of powder metallurgy (PM) material using two different surface manufacturing methods (ground and super-finished). The results were compared with previously presented results of standard gear material from the same test rig. The influence of the material (Wrought steel or PM) and surface roughness on the gea...

  8. CAUSE AND PREVENTION OF COMPACT CRACK DURING POWDER METALLURGY PRESSING%粉末冶金压坯裂纹成因与防治

    Institute of Scientific and Technical Information of China (English)

    姬成岗; 雷霆; 方树铭; 沈波涛

    2012-01-01

    作为粉末冶金的一项重要技术手段,冷等静压技术正以其突出的优越性,在许多领域取代了常规的成型技术.针对金属粉体冷等静压成形坯体在某些情况下较易产生裂纹这一现象,从粉体特性、包套材料、装料与压实、保压、卸压、脱模等涉及整个冷等静压压制过程的各个步骤,分析了产生裂纹的各种可能原因及其相应的防治措施.%As important technology of powder metallurgy, provided with outstanding superiority cold isostatic pressing replaces normal compacting techniques in many fields. Aiming at under certain conditions cracks occurring during cold isostatic pressing, from the aspect of each step of the whole cold isostatic pressing, such as powder characteristics, moulding material, filling and compacting, pressure maintaining, pressure releasing, demoulding and etc. From every step of the whole compacting process for cold isostatic pressing to metal powder which include; the features of powder, materials of mould, filling and compaction, pressure maintaining, pressure release, de-moulding and so on, this article analyzes each possible cause of cracks and the corresponding prevention measurement.

  9. Making Decisions by Analytical Chemistry

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov

    . These discrepancies are very unfortunate because erroneous conclusions may arise from an otherwise meticulous and dedicated effort of research staff. This may eventually lead to unreliable conclusions thus jeopardizing investigations of environmental monitoring, climate changes, food safety, clinical chemistry......It has been long recognized that results of analytical chemistry are not flawless, owing to the fact that professional laboratories and research laboratories analysing the same type of samples by the same type of instruments are likely to obtain significantly different results. The European......, forensics and other fields of science where analytical chemistry is the key instrument of decision making. In order to elucidate the potential origin of the statistical variations found among laboratories, a major program was undertaken including several analytical technologies where the purpose...

  10. Application of vacuum metallurgy to separate pure metal from mixed metallic particles of crushed waste printed circuit board scraps.

    Science.gov (United States)

    Zhan, Lu; Xu, Zhenming

    2008-10-15

    The principle of separating pure metal from mixed metallic particles (MMPs) byvacuum metallurgy is that the vapor pressures of various metals at the same temperature are different As a result, the metal with high vapor pressure and low boiling point can be separated from the mixed metals through distillation or sublimation, and then it can be recycled through condensation under a certain condition. The vacuum metallurgy separation (VMS) of MMPs of crushed waste printed circuit boards (WPCBs) has been studied in this paper. Theoretical analyses show that the MMPs (copper, zinc, bismuth, lead, and indium, for example) can be separated by vacuum metallurgy. The copper particles (0.15-0.20 mm) and zinc particles (<0.30 mm) were chosen to simulate the MMPs of crushed WPCBs. Experimental results show that the separated efficiency of zinc in the copper-rich particles achieves 96.19 wt % when the vacuum pressure is 0.01-0.10 Pa, the heating temperature is 1123 K, and the heating time is 105 min. Under this operation condition, the separated efficiency of zinc in the copper-rich particles from crushed WPCBs achieves 97.00 wt % and the copper purity increases from 90.68 to 99.84 wt %.

  11. Hanford Atomic Products Operation monthly report for March 1956

    Energy Technology Data Exchange (ETDEWEB)

    1956-04-20

    This is the monthly report for the Hanford Laboratories Operation, March, 1956. Metallurgy, reactor fuels, chemistry, dosimetry, separation processes, reactor technology; financial activities, visits, biology operation, physics and instrumentation research, employee relations, pile technology, safety and radiological sciences are discussed.

  12. 《中国科学技术史》"钢铁冶金"分册述评%A Review of Donald B.Wagner's Science and Civilisation in China(Ferrous Metallurgy)

    Institute of Scientific and Technical Information of China (English)

    梅建军

    2011-01-01

    @@ 李约瑟(J.Needham,1900-1995年)博士的系列专著(Scienceand Civilisation in China)自1954年出版第1卷以来,迄今已出版了24个分册.最近出版的两个分册分别是"陶瓷技术"(Ceramic Technology)与"钢铁冶金"(Ferrous Metallurgy),两者均归属于第5卷即化学和化学技术卷,是该卷总计14个分册中的第12和第11分册.

  13. 75 FR 5353 - Proposal Review Panel for Chemistry; Notice of Meeting

    Science.gov (United States)

    2010-02-02

    ... Proposal Review Panel for Chemistry; Notice of Meeting In accordance with the Federal Advisory Committee... and The University of Massachusetts, Proposal Review Panel for Chemistry ( 1191). Dates and Times...: Department of Chemistry, Georgia Institute of Technology, Atlanta, GA 30332. Department of Chemistry,...

  14. Modern steelmaking technologies

    Science.gov (United States)

    Sinel'nikov, V. A.; Filippov, G. A.; Lavrov, A. S.; Gunenkov, V. Yu.

    2016-06-01

    Based on our experimental results, we propose the following low-cost technologies in the field of steelmaking for implementation: the use of briquettes, which are alternative to solid cast iron and scrap metal and contain scale and carbon-containing wastes, in the charges of electric furnaces and converters; microalloying of metal by nitride phases; modification of steel in a ladle by SiCa + Ba master alloys; and the application of daisy-chain blowing of the metal in a ladle (small-bubble conditions). The efficiency of these technologies for melting in electric furnaces and secondary metallurgy is supported. It is shown that electromagnetic mixing of metal in combination with the optimum conditions of soft reduction of a slab should be used in continuous casting to form an internal structure in a slab at the level of the first class on the Mannesmann scale.

  15. Flow chemistry syntheses of natural products.

    Science.gov (United States)

    Pastre, Julio C; Browne, Duncan L; Ley, Steven V

    2013-12-07

    The development and application of continuous flow chemistry methods for synthesis is a rapidly growing area of research. In particular, natural products provide demanding challenges to this developing technology. This review highlights successes in the area with an emphasis on new opportunities and technological advances.

  16. Die wall lubricated warm compaction of iron-based powder metallurgy material

    Institute of Scientific and Technical Information of China (English)

    倪东惠; 陈维平; 肖志瑜; 温利平; 吴苑标

    2002-01-01

    Lubricant is harmful to the mechanical properties of the sintered materials. Die wall lubrication was applied on warm compaction powder metallurgy in the hope of reducing the concentration level of the admixed lubricant. Iron-based samples were prepared by die wall lubricated warm compaction at 175℃, using a compacting pressure of 550MPa. Emulsified polytetrafluoroethylene(PTFE) was used as die wall lubricant. Admixed lubricant concentration ranging from 0 to 0.5% was tested. Extremely low admixed lubricant contents were used. Results show that in addition to the decrease in ejection forces, the green density of the compacts increases with the decrease of admixed lubricant content until it reaches the maximum at 0.06% of lubricant content, then decreases with the decrease of admixed lubricant content. The mechanical properties of the sintered compacts that contain more than 0.06% admixed lubricant are better than those of the samples that contain lesser lubricant. No scoring was observed in all die wall lubricated experiments.

  17. Analysis of Load Transfer Mechanism in Cu Reinforced with Carbon Nanotubes Fabricated by Powder Metallurgy Route

    Science.gov (United States)

    Akbarpour, Mohammad Reza

    2016-05-01

    In this research, ductile and high-strength Cu-carbon nanotube (Cu-CNT) composites with different volume fractions of CNTs were fabricated using powder metallurgy route including mechanical milling and hot pressing and microstructure and tensile properties of the resulting materials were studied. Microstructural characterization through scanning electron microscope and quantifying the CNT agglomeration revealed that uniform dispersion of CNTs in Cu matrix decreases with increasing CNT volume fraction. In case of the higher volume fraction of CNTs (i.e., 8 vol.%), ~ 40% of CNTs were observed as agglomerates in the microstructure. Compared to unreinforced Cu, the yield and ultimate tensile strengths increased considerably (about 33% and 12%, respectively) with incorporation of CNTs up to 4 vol.%, but remained constant afterward. Meanwhile, the elongation decreased from 15.6% for Cu to 6.9% for Cu with 8 vol.% CNT. The relationship between the change in yield strength of the composite and the microstructure was investigated using analytical models. The results showed good consistency between calculated and measured data when the negative effect of CNT agglomerates in the models were taken into account.

  18. Tribological properties of PM212: A high-temperature, self-lubricating, powder metallurgy composite

    Science.gov (United States)

    Dellacorte, Christopher; Sliney, Harold E.

    1989-01-01

    This paper describes a research program to develop and evaluate a new high temperature, self-lubricating powder metallurgy composite, PM212. PM212 has the same composition as the plasma-sprayed coating, PS212, which contains 70 wt percent metal-bonded chromium carbide, 15 wt percent silver and 15 wt percent barium fluoride/calcium fluoride eutectic. The carbide acts as a wear resistant matrix and the silver and fluorides act as low and high temperature lubricants, respectively. The material is prepared by sequential cold press, cold isostatic pressing and sintering techniques. In this study, hemispherically tipped wear pins of PM212 were prepared and slid against superalloy disks at temperatures from 25 to 850 C in air in a pin-on-disk tribometer. Friction coefficients range from 0.29 to 0.38 and the wear of both the composite pins and superalloy disks was moderate to low in the 10(exp -5) to 10(exp -6) cubic mm/N-m range. Preliminary tests indicate that the material has a compressive strength of at least 130 MPa over the entire temperature range of 25 to 900 C. This material has promise for use as seal inserts, bushings, small inside diameter parts and other applications where plasma-sprayed coatings are impractical or too costly.

  19. Power-law creep of powder-metallurgy grade molybdenum sheet

    Energy Technology Data Exchange (ETDEWEB)

    Ciulik, J. [University of Texas at Austin, Mechanical Engineering Department, 1 University Station, C2200, Austin, TX 78712-0292 (United States)], E-mail: jciulik@mail.utexas.edu; Taleff, E.M. [University of Texas at Austin, Mechanical Engineering Department, 1 University Station, C2200, Austin, TX 78712-0292 (United States)

    2007-08-15

    Creep behavior of commercial-purity, powder-metallurgy grade molybdenum (Mo) sheet has been investigated at temperatures between 1300 and 1600 deg. C (0.56-0.63 T{sub m}) using tensile testing at controlled strain rates. Strain-rate-change tests were performed at constant-temperatures over true-strain rates from 1.0 x 10{sup -6} to 5.0 x 10{sup -4} s{sup -1}. Results agree with previously published data indicating that Mo follows power-law creep with a stress exponent of about 5; however, the present results address a temperature range not previously documented. The activation energy for creep was determined to be 240 kJ/mol within this temperature range, which is lower than previously published values and approximately half the value reported for self-diffusion, indicating that diffusion mechanisms faster than lattice diffusion are active. It is shown that Mo creep data from a variety of investigations converge closely to a single line on a master plot of strain rate normalized using an activation energy of 240 kJ/mol when plotted against stress normalized by the temperature-dependent elastic modulus. This activation energy for creep is attributed to an effective diffusivity that fits the creep data obtained during this study as well as from previously published creep data from commercial-purity molybdenum.

  20. Niobium-titanium superconductors produced by powder metallurgy having artificial flux pinning centers

    Science.gov (United States)

    Jablonski, Paul D.; Larbalestier, David C.

    1993-01-01

    Superconductors formed by powder metallurgy have a matrix of niobium-titanium alloy with discrete pinning centers distributed therein which are formed of a compatible metal. The artificial pinning centers in the Nb-Ti matrix are reduced in size by processing steps to sizes on the order of the coherence length, typically in the range of 1 to 10 nm. To produce the superconductor, powders of body centered cubic Nb-Ti alloy and the second phase flux pinning material, such as Nb, are mixed in the desired percentages. The mixture is then isostatically pressed, sintered at a selected temperature and selected time to produce a cohesive structure having desired characteristics without undue chemical reaction, the sintered billet is reduced in size by deformation, such as by swaging, the swaged sample receives heat treatment and recrystallization and additional swaging, if necessary, and is then sheathed in a normal conducting sheath, and the sheathed material is drawn into a wire. The resulting superconducting wire has second phase flux pinning centers distributed therein which provide enhanced J.sub.ct due to the flux pinning effects.

  1. The Promotion of Liquid Phase Sintering of Boron-Containing Powder Metallurgy Steels by Adding Nickel

    Directory of Open Access Journals (Sweden)

    Wu Ming-Wei

    2015-01-01

    Full Text Available Boron is a feasible alloying element for liquid phase sintering (LPS of powder metallurgy (PM steels. This study investigated the effect of nickel (Ni, which is widely used in PM steels, on the liquid phase sintering of boron-containing PM steels. The results showed that the addition of 1.8wt% Ni does not apparently modify the LPS mechanism of boron-containing PM steels. However, adding 1.8wt% Ni slightly improves the LPS densification from 0.60 g/cm3 to 0.65 g/cm3, though the green density is reduced. Thermodynamic simulation demonstrated that the presence of Ni lowers the temperature region of liquid formation, resulting in enhanced LPS densification. Moreover, original graphite powders remains in the steels sintered at 1200 ºC. These graphite powders mostly dissolve into the base iron powder when the sintering temperature is increased from 1200 ºC to 1250 ºC.

  2. Emissions from pre-Hispanic metallurgy in the South American atmosphere.

    Science.gov (United States)

    De Vleeschouwer, François; Vanneste, Heleen; Mauquoy, Dmitri; Piotrowska, Natalia; Torrejón, Fernando; Roland, Thomas; Stein, Ariel; Le Roux, Gaël

    2014-01-01

    Metallurgical activities have been undertaken in northern South America (NSA) for millennia. However, it is still unknown how far atmospheric emissions from these activities have been transported. Since the timing of metallurgical activities is currently estimated from scarce archaeological discoveries, the availability of reliable and continuous records to refine the timing of past metal deposition in South America is essential, as it provides an alternative to discontinuous archives, as well as evidence for global trace metal transport. We show in a peat record from Tierra del Fuego that anthropogenic metals likely have been emitted into the atmosphere and transported from NSA to southern South America (SSA) over the last 4200 yrs. These findings are supported by modern time back-trajectories from NSA to SSA. We further show that apparent anthropogenic Cu and Sb emissions predate any archaeological evidence for metallurgical activities. Lead and Sn were also emitted into the atmosphere as by-products of Inca and Spanish metallurgy, whereas local coal-gold rushes and the industrial revolution contributed to local contamination. We suggest that the onset of pre-Hispanic metallurgical activities is earlier than previously reported from archaeological records and that atmospheric emissions of metals were transported from NSA to SSA.

  3. Emissions from pre-Hispanic metallurgy in the South American atmosphere.

    Directory of Open Access Journals (Sweden)

    François De Vleeschouwer

    Full Text Available Metallurgical activities have been undertaken in northern South America (NSA for millennia. However, it is still unknown how far atmospheric emissions from these activities have been transported. Since the timing of metallurgical activities is currently estimated from scarce archaeological discoveries, the availability of reliable and continuous records to refine the timing of past metal deposition in South America is essential, as it provides an alternative to discontinuous archives, as well as evidence for global trace metal transport. We show in a peat record from Tierra del Fuego that anthropogenic metals likely have been emitted into the atmosphere and transported from NSA to southern South America (SSA over the last 4200 yrs. These findings are supported by modern time back-trajectories from NSA to SSA. We further show that apparent anthropogenic Cu and Sb emissions predate any archaeological evidence for metallurgical activities. Lead and Sn were also emitted into the atmosphere as by-products of Inca and Spanish metallurgy, whereas local coal-gold rushes and the industrial revolution contributed to local contamination. We suggest that the onset of pre-Hispanic metallurgical activities is earlier than previously reported from archaeological records and that atmospheric emissions of metals were transported from NSA to SSA.

  4. The substitution of nickel for cobalt in hot isostatically pressed powder metallurgy UDIMET 700 alloys

    Science.gov (United States)

    Harf, F. H.

    1985-01-01

    Nickel was substituted in various proportions for cobalt in a series of five hot-isostatically-pressed powder metallurgy alloys based on the UDIMET 700 composition. These alloys were given 5-step heat treatments appropriate for use in turbine engine disks. The resultant microstructures displayed three distinct sizes of gamma-prime particles in a gamma matrix. The higher cobalt-content alloys contained larger amounts of the finest gamma-prime particles, and had the lowest gamma-gamma-prime lattice mismatch. While all alloys had approximately the same tensile properties at 25 and 650 gamma C, the rupture lives at 650 and 760 C peaked in the alloys with cobalt contents between 12.7 and 4.3 pct. Minimum creep rates increased as cobalt contents were lowered, suggesting their correlation with the gamma-prime particle size distribution and the gamma-gamma-prime mismatch. It was also found that, on overaging at temperatures higher than suitable for turbine disk use, the high cobalt-content alloys were prone to sigma phase formation.

  5. Tribological Properties of the Fe-Al-Cr Alloyed Layer by Double Glow Plasma Surface Metallurgy

    Science.gov (United States)

    Luo, Xixi; Yao, Zhengjun; Zhang, Pingze; Zhou, Keyin; Wang, Zhangzhong

    2016-09-01

    A Fe-Al-Cr alloyed layer was deposited onto the surface of Q235 low-carbon steel via double glow plasma surface metallurgy (DGPSM) to improve the steel's wear resistance. After the DGPSM treatment, the Fe-Al-Cr alloyed layer grown on the Q235 low-carbon steel was homogeneous and compact and had a thickness of 25 µm. The layer was found to be metallurgically adhered to the substrate. The frictional coefficient and specific wear rate of the sample with a Fe-Al-Cr alloyed layer (treated sample) were both lower than those of the bare substrate (untreated sample) at the measured temperatures (25, 250 and 450 °C). The results indicated that the substrate and the alloyed layer suffered oxidative wear and abrasive wear, respectively, and that the treated samples exhibited much better tribological properties than did the substrate. The formation of Fe2AlCr, Fe3Al(Cr), FeAl(Cr), Fe(Cr) sosoloid and Cr23C6 phases in the alloyed layer dramatically enhanced the wear resistance of the treated sample. In addition, the alloyed layer's oxidation film exhibited a self-healing capacity with lubrication action that also contributed to the improvement of the wear resistance at high temperature. In particular, at 450 °C, the specific wear rate of treated sample was 2.524 × 10-4 mm3/N m, which was only 45.2% of the untreated sample.

  6. Tribological behavior of liquid metallurgy-processed AA 6061-B4C composites

    Science.gov (United States)

    Monikandan, V. V.; Joseph, M. A.; Rajendrakumar, P. K.; Sreejith, M.

    2015-01-01

    Aluminum metal matrix composites (AMMCs) possess improved properties compared to their monolithic counterparts and serve as a reliable alternative to replace them for applications that are considered as their niche. In the present investigation, 6061 Al alloy-10 wt% B4C composite is fabricated through liquid metallurgy stir casting technique and analyzed for its tribological characteristics. The uniform distribution of B4C reinforcement particles in the composite is achieved by the above route and is characterized using microstructure analysis and x-ray diffraction spectrum. The dry wear tests have been conducted under ambient conditions using a pin-on-disc tribometer. The worn surface and debris of the composite are also characterized using a scanning electron microscope (SEM) and energy-dispersive x-ray spectroscopy (EDS). It is found that the combination of adhesion, delamination and abrasion constitute the predominant wear mechanism and this is influenced by the B4C particles, applied load, sliding distance and speed. The wear and friction coefficient increase with increase in applied load for all the load conditions studied. While the sliding speed fosters the engendering of a mechanically mixed layer (MML) to reduce the wear and friction coefficient, in contrast, the increase in sliding distance scuttles the MML formation owing to abrasion induced by the hard B4C particles.

  7. An investigation of wear behaviors of different Monel alloys produced by powder metallurgy

    Science.gov (United States)

    Esgin, U.; Özyürek, D.; Kaya, H.

    2016-04-01

    In the present study, wear behaviors of Monel 400, Monel 404, Monel R-405 and Monel K-500 alloys produced by Powder Metallurgy (P/M) method were investigated. These compounds prepared from elemental powders were cold-pressed (600 MPa) and then, sintered at 1150°C for 2 hours and cooled down to the room temperature in furnace environment. Monel alloys produced by the P/M method were characterized through scanning electron microscope (SEM+EDS), X-ray diffraction (XRD), hardness and density measurements. In wear tests, standard pin-on-disk type device was used. Specimens produced within four different Monel Alloys were tested under 1ms-1 sliding speed, under three different loads (20N, 30N and 40N) and five different sliding distances (400-2000 m). The results show that Monel Alloys have γ matrix and that Al0,9Ni4,22 intermetallic phase was formed in the structure. Also, the highest hardness value was measured with the Monel K-500 alloy. In wear tests, the maximum weight loss according to the sliding distance, was observed in Monel 400 and Monel 404 alloys while the minimum weight loss was achieved by the Monel K-500 alloy.

  8. In-situ surface hardening of cast iron by surface layer metallurgy

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Sebastian F., E-mail: s.fischer@gi.rwth-aachen.de [Foundry Institute, RWTH Aachen University, Intzestraße 5, 52072 Aachen (Germany); Muschna, Stefan, E-mail: smuschna@yahoo.de [Foundry Institute, RWTH Aachen University, Intzestraße 5, 52072 Aachen (Germany); Bührig-Polaczek, Andreas, E-mail: sekretariat@gi.rwth-aachen.de [Foundry Institute, RWTH Aachen University, Intzestraße 5, 52072 Aachen (Germany); Bünck, Matthias, E-mail: m.buenck@access-techcenter.de [Access e.V., Intzestraße 5, 52072 Aachen (Germany)

    2014-10-06

    Abrasive wear is a serious problem in many cast iron castings used in industry. To minimize failure and repair of these components, different strategies exist to improve their surface microhardness thus enhancing their wear resistance. However, most of these methods lead to very brittle and/or expensive castings. In the current work a new method for surface hardening is presented which utilizes surface layer metallurgy to generate in-situ a boron-enriched white cast iron surface layer with a high microhardness on a gray cast iron casting. To do this, sand molds are coated with a ferroboron suspension and cast with a cast iron melt. After solidification, a 100–900 µm thick layer of boron-enriched ledeburite is formed on the surface of the casting which produces an increase in the average microhardness from 284 HV{sub 0.1}±52 HV{sub 0.1} to 505 HV{sub 0.1}±87 HV{sub 0.1}. Analyses of the samples' core reveal a typical cast iron microstructure which leads to the conclusion that the coating mainly affects the castings' surface. By varying the grain size of the ferroboron powder in the coatings, it is shown that a powder size ≤100 µm is most suitable to create a boron-enriched ledeburite surface layer possessing high hardness values.

  9. State-of-the-art of recycling e-wastes by vacuum metallurgy separation.

    Science.gov (United States)

    Zhan, Lu; Xu, Zhenming

    2014-12-16

    In recent era, more and more electric and electronic equipment wastes (e-wastes) are generated that contain both toxic and valuable materials in them. Most studies focus on the extraction of valuable metals like Au, Ag from e-wastes. However, the recycling of metals such as Pb, Cd, Zn, and organics has not attracted enough attentions. Vacuum metallurgy separation (VMS) processes can reduce pollution significantly using vacuum technique. It can effectively recycle heavy metals and organics from e-wastes in an environmentally friendly way, which is beneficial for both preventing the heavy metal contaminations and the sustainable development of resources. VMS can be classified into several methods, such as vacuum evaporation, vacuum carbon reduction and vacuum pyrolysis. This paper respectively reviews the state-of-art of these methods applied to recycling heavy metals and organics from several kinds of e-wastes. The method principle, equipment used, separating process, optimized operating parameters and recycling mechanism of each case are illustrated in details. The perspectives on the further development of e-wastes recycling by VMS are also presented.

  10. Factors Influencing Dwell Fatigue Cracking in Notches of Powder Metallurgy Superalloys

    Science.gov (United States)

    Gabb, T. P.; Telesman, J.; Ghosn, L.; Garg, A.; Gayda, J.

    2011-01-01

    The influences of heat treatment and cyclic dwells on the notch fatigue resistance of powder metallurgy disk superalloys were investigated for low solvus high refractory (LSHR) and ME3 disk alloys. Disks were processed to produce material conditions with varied microstructures and associated mechanical properties. Notched specimens were first subjected to baseline dwell fatigue cycles having a dwell at maximum load, as well as tensile, stress relaxation, creep rupture, and dwell fatigue crack growth tests at 704 C. Several material heat treatments displayed a bimodal distribution of fatigue life with the lives varying by two orders-of-magnitude, while others had more consistent fatigue lives. This response was compared to other mechanical properties, in search of correlations. The wide scatter in baseline dwell fatigue life was observed only for material conditions resistant to stress relaxation. For selected materials and conditions, additional tests were then performed with the dwells shifted in part or in total to minimum tensile load. The tests performed with dwells at minimum load exhibited lower fatigue lives than max dwell tests, and also exhibited early crack initiation and a substantial increase in the number of initiation sites. These results could be explained in part by modeling evolution of peak stresses in the notch with continued dwell fatigue cycling. Fatigue-environment interactions were determined to limit life for the fatigue cycles with dwells.

  11. Feasibility study of the production of biomedical Ti-6Al-4V alloy by powder metallurgy.

    Science.gov (United States)

    Bolzoni, L; Ruiz-Navas, E M; Gordo, E

    2015-04-01

    Titanium and its alloys are characterized by an exceptional combination of properties like high strength, good corrosion resistance and biocompatibility which makes them suitable materials for biomedical prosthesis and devices. The wrought Ti-6Al-4V alloy is generally favored in comparison to other metallic biomaterials due to its relatively low elastic modulus and it has been long used to obtain products for biomedical applications. In this work an alternative route to fabricate biomedical implants made out of the Ti-6Al-4V alloy is investigated. Specifically, the feasibility of the conventional powder metallurgy route of cold uniaxial pressing and sintering is addressed by considering two types of powders (i.e. blended elemental and prealloyed). The characterization of physical properties, chemical analysis, mechanical behavior and microstructural analysis is carried out in-depth and the properties are correlated among them. On the base of the results found, the produced alloys are promising materials for biomedical applications as well as cheaper surgical devices and tools.

  12. Application of powder metallurgy techniques to produce improved bearing elements for liquid rocket engines

    Science.gov (United States)

    Moracz, D. J.; Shipley, R. J.; Moxson, V. S.; Killman, R. J.; Munson, H. E.

    1992-01-01

    The objective was to apply powder metallurgy techniques for the production of improved bearing elements, specifically balls and races, for advanced cryogenic turbopump bearings. The materials and fabrication techniques evaluated were judged on the basis of their ability to improve fatigue life, wear resistance, and corrosion resistance of Space Shuttle Main Engine (SSME) propellant bearings over the currently used 440C. An extensive list of candidate bearing alloys in five different categories was considered: tool/die steels, through hardened stainless steels, cobalt-base alloys, and gear steels. Testing of alloys for final consideration included hardness, rolling contact fatigue, cross cylinder wear, elevated temperature wear, room and cryogenic fracture toughness, stress corrosion cracking, and five-ball (rolling-sliding element) testing. Results of the program indicated two alloys that showed promise for improved bearing elements. These alloys were MRC-2001 and X-405. 57mm bearings were fabricated from the MRC-2001 alloy for further actual hardware rig testing by NASA-MSFC.

  13. In vitro bioactivity of a biocomposite fabricated from HA and Ti powders by powder metallurgy method.

    Science.gov (United States)

    Ning, C Q; Zhou, Y

    2002-07-01

    Traditionally, hydroxyapatite was used as a coating material on titanium substrate by various techniques. In the present work, a biocomposite was successfully fabricated from hydroxyapatite and titanium powders by powder metallurgy method. Bioactivity of the composite in a simulated body fluid (SBF) was investigated. Main crystal phases of the as-fabricated composite are found to be Ti2O, CaTiO3, CaO, alpha-Ti and a TiP-like phase. When the composite is immersed in the simulated body fluid for a certain time, a poor-crystallized, calcium-deficient, carbonate-containing apatite film will form on the surface of the composite. The time required to induce apatite nucleation is within 2 h. In addition, the apatite is also incorporated with a little magnesium and chlorine element. It is found that Ti2O has the ability to induce the formation of bone-like apatite in the SBF. And a dissolve of the CaO phase could also provide favorable conditions for the apatite formation, by forming open pores on the surface of the composite and increasing the degree of supersaturation of the SBF with respect to the apatite.

  14. Tribological properties of PM212 - A high temperature, self-lubricating, powder metallurgy composite

    Science.gov (United States)

    Dellacorte, Christopher; Sliney, Harold E.

    1990-01-01

    This paper describes a research program to develop and evaluate a new high temperature, self-lubricating powder metallurgy composite, PM212. PM212 has the same composition as the plasma-sprayed coating, PS212, which contains 70 wt percent metal-bonded chromium carbide, 15 wt percent silver and 15 wt percent barium fluoride/calcium fluoride eutectic. The carbide acts as a wear resistant matrix and the silver and fluorides act as low and high temperature lubricants, respectively. The material is prepared by sequential cold press, cold isostatic pressing and sintering techniques. In this study, hemispherically tipped wear pins of PM212 were prepared and slid against superalloy disks at temperatures from 25 to 850 C in air in a pin-on-disk tribometer. Friction coefficients range from 0.29 to 0.38 and the wear of both the composite pins and superalloy disks was moderate to low in the 10(exp -5) to 10(exp -6) cubic mm/N-m range. Preliminary tests indicate that the material has a compressive strength of at least 130 MPa over the entire temperature range of 25 to 900 C. This material has promise for use as seal inserts, bushings, small inside diameter parts and other applications where plasma-sprayed coatings are impractical or too costly.

  15. Compressibility of 304 Stainless Steel Powder Metallurgy Materials Reinforced with 304 Short Stainless Steel Fibers

    Directory of Open Access Journals (Sweden)

    Bibo Yao

    2016-03-01

    Full Text Available Powder metallurgy (P/M technique is usually used for manufacturing porous metal materials. However, some P/M materials are limitedly used in engineering for their performance deficiency. A novel 304 stainless steel P/M material was produced by a solid-state sintering of 304 stainless steel powders and 304 short stainless steel fibers, which were alternately laid in layers according to mass ratio. In this paper, the compressive properties of the P/M materials were characterized by a series of uniaxial compression tests. The effects of fiber content, compaction pressure and high temperature nitriding on compressive properties were investigated. The results indicated that, without nitriding, the samples changed from cuboid to cydariform without damage in the process of compression. The compressive stress was enhanced with increasing fiber content ranging from 0 to 8 wt.%. For compaction pressure from 55 to 75 MPa, greater compaction pressure improved compressive stress. Moreover, high temperature nitriding was able to significantly improve the yield stress, but collapse failure eventually occurred.

  16. Application of powder metallurgy technique to produce improved bearing elements for cryogenic aerospace engine turbopumps

    Science.gov (United States)

    Moxson, V. S.; Moracz, D. J.; Bhat, B. N.; Dolan, F. J.; Thom, R.

    1987-01-01

    Traditionally, vacuum melted 440C stainless steel is used for high performance bearings for aerospace cryogenic systems where corrosion due to condensation is a major concern. For the Space Shuttle Main Engine (SSME), however, 440C performance in the high-pressure turbopumps has been marginal. A basic assumption of this study was that powder metallurgy, rather than cast/wrought, processing would provide the finest, most homogeneous bearing alloy structure. Preliminary testing of P/M alloys (hardness, corrosion resistance, wear resistance, fatigue resistance, and fracture toughness) was used to 'de-select' alloys which did perform as well as baseline 440C. Five out of eleven candidate materials (14-4/6V, X-405, MRC-2001, T-440V, and D-5) based on preliminary screening were selected for the actual rolling-sliding five-ball testing. The results of this test were compared with high-performance vacuum-melted M50 bearing steel. The results of the testing indicated outstanding performance of two P/M alloys, X-405 and MRC-2001, which eventually will be further evaluated by full-scale bearing testing.

  17. Titanium nitride deposition in titanium implant alloys produced by powder metallurgy

    Energy Technology Data Exchange (ETDEWEB)

    Henriques, V.A.R.; Cairo, C.A.A.; Faria, J., E-mail: vinicius@iae.cta.br, E-mail: ccairo@iae.cta.br, E-mail: juliacfaria@gmail.com [Instituto de Aeronautica e Espaco (AMR/CTA/IAE), Sao Jose dos Campos, SP (Brazil). Centro Tecnico Aeroespacial. Divisao de Materiais; Lemos, T.G., E-mail: tgorla@hotmail.com [Universidade de Sao Paulo (DEMAR/EEL/USP), Lorena, SP (Brazil). Escola de Engenharia; Galvani, E.T., E-mail: eduardotgalvani@yahoo.com.br [Instituto Tecnologico de Aeronautica (CTA/ITA), Sao Jose dos Campos, SP (Brazil). Centro Tecnico Aeroespacial

    2009-07-01

    Titanium nitride (TiN) is an extremely hard material, often used as a coating on titanium alloy, steel, carbide, and aluminum components to improve wear resistance. Electron Beam Physical Vapor Deposition (EB-PVD) is a form of deposition in which a target anode is bombarded with an electron beam given off by a charged tungsten filament under high vacuum, producing a thin film in a substrate. In this work are presented results of TiN deposition in targets and substrates of Ti (C.P.) and Ti-{sup 13}Nb-{sup 13}Zr obtained by powder metallurgy. Samples were produced by mixing of hydride metallic powders followed by uniaxial and cold isostatic pressing with subsequent densification by sintering between 900°C up to 1400 °C, in vacuum. The deposition was carried out under nitrogen atmosphere. Sintered samples were characterized for phase composition, microstructure and microhardness by X-ray diffraction, scanning electron microscopy and Vickers indentation, respectively. It was shown that the samples were sintered to high densities and presented homogeneous microstructure, with ideal characteristics for an adequate deposition and adherence. The film layer presented a continuous structure with 15μm. (author)

  18. Production of a low young modulus titanium alloy by powder metallurgy

    Directory of Open Access Journals (Sweden)

    Dalcy Roberto dos Santos

    2005-12-01

    Full Text Available Titanium alloys have several advantages over ferrous and non-ferrous metallic materials, such as high strengthto-weight ratio and excellent corrosion resistance. A blended elemental titanium powder metallurgy process has been developed to offer low cost commercial products. The process employs hydride-dehydride (HDH powders as raw material. In this work, results of the Ti-35Nb alloy sintering are presented. This alloy due to its lower modulus of elasticity and high biocompatibility is a promising candidate for aerospace and medical use. Samples were produced by mixing of initial metallic powders followed by uniaxial and cold isostatic pressing with subsequent densification by isochronal sintering between 900 up to 1600 °C, in vacuum. Sintering behavior was studied by means of microscopy and density. Sintered samples were characterized for phase composition, microstructure and microhardness by X-ray diffraction, scanning electron microscopy and Vickers indentation, respectively. Samples sintered at high temperatures display a fine plate-like alpha structure and intergranular beta. A few remaining pores are still found and density above 90% for specimens sintered in temperatures over 1500 °C is reached.

  19. Dwell Notch Low Cycle Fatigue Behavior of a Powder Metallurgy Nickel Disk Alloy

    Science.gov (United States)

    Telesman, J.; Gabb, T. P.; Yamada, Y.; Ghosn, L. J.; Jayaraman, N.

    2012-01-01

    A study was conducted to determine the processes which govern dwell notch low cycle fatigue (NLCF) behavior of a powder metallurgy (P/M) ME3 disk superalloy. The emphasis was placed on the environmentally driven mechanisms which may embrittle the highly stressed notch surface regions and reduce NLCF life. In conjunction with the environmentally driven notch surface degradation processes, the visco-plastic driven mechanisms which can significantly change the notch root stresses were also considered. Dwell notch low cycle fatigue testing was performed in air and vacuum on a ME3 P/M disk alloy specimens heat treated using either a fast or a slow cooling rate from the solutioning treatment. It was shown that dwells at the minimum stress typically produced a greater life debit than the dwells applied at the maximum stress, especially for the slow cooled heat treatment. Two different environmentally driven failure mechanisms were identified as the root cause of early crack initiation in the min dwell tests. Both of these failure mechanisms produced mostly a transgranular crack initiation failure mode and yet still resulted in low NLCF fatigue lives. The lack of stress relaxation during the min dwell tests produced higher notch root stresses which caused early crack initiation and premature failure when combined with the environmentally driven surface degradation mechanisms. The importance of environmental degradation mechanisms was further highlighted by vacuum dwell NLCF tests which resulted in considerably longer NLCF lives, especially for the min dwell tests.

  20. Characterisation of titanium-titanium boride composites processed by powder metallurgy techniques

    Energy Technology Data Exchange (ETDEWEB)

    Selva Kumar, M., E-mail: sel_mcet@yahoo.co.in [Department of Mechanical Engineering, Dr. Mahalingam College of Engineering and Technology, Pollachi-642003 (India); Chandrasekar, P.; Chandramohan, P. [School of Engineering, Professional Group of Institutions, Coimbatore-641662 (India); Mohanraj, M. [Department of Mechanical Engineering, Info Institute of Engineering, Coimbatore-641107 (India)

    2012-11-15

    In this work, a detailed characterisation of titanium-titanium boride composites processed by three powder metallurgy techniques, namely, hot isostatic pressing, spark plasma sintering and vacuum sintering, was conducted. Two composites with different volume percents of titanium boride reinforcement were used for the investigation. One was titanium with 20% titanium boride, and the other was titanium with 40% titanium boride (by volume). Characterisation was performed using X-ray diffraction, electron probe micro analysis - energy dispersive spectroscopy and wavelength dispersive spectroscopy, image analysis and scanning electron microscopy. The characterisation results confirm the completion of the titanium boride reaction. The results reveal the presence of titanium boride reinforcement in different morphologies such as needle-shaped whiskers, short agglomerated whiskers and fine plates. The paper also discusses how mechanical properties such as microhardness, elastic modulus and Poisson's ratio are influenced by the processing techniques as well as the volume fraction of the titanium boride reinforcement. - Highlights: Black-Right-Pointing-Pointer Ti-TiB composites were processed by HIP, SPS and vacuum sintering. Black-Right-Pointing-Pointer The completion of Ti-TiB{sub 2} reaction was confirmed by XRD, SEM and EPMA studies. Black-Right-Pointing-Pointer Hardness and elastic properties of Ti-TiB composites were discussed. Black-Right-Pointing-Pointer Processing techniques were compared with respect to their microstructure.

  1. Uranium silicide pellet fabrication by powder metallurgy for accident tolerant fuel evaluation and irradiation

    Science.gov (United States)

    Harp, Jason M.; Lessing, Paul A.; Hoggan, Rita E.

    2015-11-01

    In collaboration with industry, Idaho National Laboratory is investigating uranium silicide for use in future light water reactor fuels as a more accident resistant alternative to uranium oxide base fuels. Specifically this project was focused on producing uranium silicide (U3Si2) pellets by conventional powder metallurgy with a density greater than 94% of the theoretical density. This work has produced a process to consistently produce pellets with the desired density through careful optimization of the process. Milling of the U3Si2 has been optimized and high phase purity U3Si2 has been successfully produced. Results are presented from sintering studies and microstructural examinations that illustrate the need for a finely ground reproducible particle size distribution in the source powder. The optimized process was used to produce pellets for the Accident Tolerant Fuel-1 irradiation experiment. The average density of these pellets was 11.54 ± 0.06 g/cm3. Additional characterization of the pellets by scanning electron microscopy and X-ray diffraction has also been performed. Pellets produced in this work have been encapsulated for irradiation, and irradiation in the Advanced Test Reactor is expected soon.

  2. Cooling γ precipitation behavior and strengthening in powder metallurgy superalloy FGH4096

    Institute of Scientific and Technical Information of China (English)

    TIAN Gaofeng; JIA Chengchang; WEN Yin; LIU Guoquan; HU Benfu

    2008-01-01

    Two cooling schemes (continuous cooling and interrupted cooling tests) were applied to investigate the cooling γ precipitation behavior in powder metallurgy superalloy FGH4096.The effect of cooling rate on cooling γ precipitation and the development of γ precipitates during cooling process were involved in this study.The ultimate tensile strength (UTS) of the specimens in various cooling circumstances was tested.The experiential equations were obtained between the average sizes of secondary and tertiary γ precipitates,the strength,and cooling rate.The results show that they are inversely correlated with the cooling rate as well as the grain boundary changes from serrated to straight,the shape of secondary γ precipitates changes from irregular cuboidal to spherical,while the formed tertiary γ precipitates are always spherical.The interrupted cooling tests show that the average size of secondary γ precipitates increases as a linear function of interrupt temperature for a fixed cooling rate of 24℃/min.The strength first decreases and then increases against interrupt temperature,which is fundamentally caused by the multistage nucleation of γ precipitates during cooling process.

  3. Bridging the gap between metallurgy and fatigue reliability of hydraulic turbine runners

    Science.gov (United States)

    Thibault, D.; Gagnon, M.; Godin, S.

    2014-03-01

    The failure of hydraulic turbine runners is a very rare event. Hence, in order to assess the reliability of these components, one cannot rely on statistical models based on the number of failures in a given population. However, as there is a limited number of degradation mechanisms involved, it is possible to use physically-based reliability models. Such models are more complicated but have the advantage of being able to account for physical parameters in the prediction of the evolution of runner degradation. They can therefore propose solutions to help improve reliability. With the use of such models, the effect of materials properties on runner reliability can easily be illustrated. This paper will present a brief review of the Kitagawa-Takahashi diagram that links the damage tolerance approach, based on fracture mechanics, to the stress or strain-life approaches. This diagram is at the centre of the reliability model used in this study. Using simplified response spectra obtained from on-site runner stress measurements, the paper will show how fatigue reliability is impacted by materials fatigue properties, namely fatigue crack propagation behaviour and fatigue limit obtained on S-N curves. It will also present a review of the most important microstructural features of 13%Cr- 4%Ni stainless steels used for runner manufacturing and will review how they influence fatigue properties in an effort to bridge the gap between metallurgy and turbine runners reliability.

  4. Anodization Mechanism on SiC Nanoparticle Reinforced Al Matrix Composites Produced by Power Metallurgy

    Directory of Open Access Journals (Sweden)

    Sonia C. Ferreira

    2014-12-01

    Full Text Available Specimens of aluminum-based composites reinforced by silicon carbide nanoparticles (Al/SiCnp produced by powder metallurgy (PM were anodized under voltage control in tartaric-sulfuric acid (TSA. In this work, the influence of the amount of SiCnp on the film growth during anodizing was investigated. The current density versus time response and the morphology of the porous alumina film formed at the composite surface are compared to those concerning a commercial aluminum alloy (AA1050 anodized under the same conditions. The processing method of the aluminum alloys influences the efficiency of the anodizing process, leading to a lower thicknesses for the unreinforced Al-PM alloy regarding the AA1050. The current density versus time response is strongly dependent on the amount of SiCnp. The current peaks and the steady-state current density recorded at each voltage step increases with the SiCnp volume fraction due to the oxidation of the SiCnp. The formation mechanism of the anodic film on Al/SiCnp composites is different from that occurring in AA1050, partly due the heterogeneous distribution of the reinforcement particles in the metallic matrix, but also to the entrapment of SiCnp in the anodic film.

  5. Interfacial metallurgy study of brazed joints between tungsten and fusion related materials for divertor design

    Science.gov (United States)

    Zhang, Yuxuan; Galloway, Alexander; Wood, James; Robbie, Mikael Brian Olsson; Easton, David; Zhu, Wenzhong

    2014-11-01

    In the developing DEMO divertor, the design of joints between tungsten to other fusion related materials is a significant challenge as a result of the dissimilar physical metallurgy of the materials to be joined. This paper focuses on the design and fabrication of dissimilar brazed joints between tungsten and fusion relevant materials such as EUROFER 97, oxygen-free high thermal conductivity (OFHC) Cu and SS316L using a gold based brazing foil. The main objectives are to develop acceptable brazing procedures for dissimilar joining of tungsten to other fusion compliant materials and to advance the metallurgical understanding within the interfacial region of the brazed joint. Four different butt-type brazed joints were created and characterised, each of which were joined with the aid of a thin brazing foil (Au80Cu19Fe1, in wt.%). Microstructural characterisation and elemental mapping in the transition region of the joint was undertaken and, thereafter, the results were analysed as was the interfacial diffusion characteristics of each material combination produced. Nano-indentation tests are performed at the joint regions and correlated with element composition information in order to understand the effects of diffused elements on mechanical properties. The experimental procedures of specimen fabrication and material characterisation methods are presented. The results of elemental transitions after brazing are reported. Elastic modulus and nano-hardness of each brazed joints are reported.

  6. Industrial Chemistry and School Chemistry: Making Chemistry Studies More Relevant

    Science.gov (United States)

    Hofstein, Avi; Kesner, Miri

    2006-01-01

    In this paper, we present the development and implementation over the period of more than 15 years of learning materials focusing on industrial chemistry as the main theme. The work was conducted in the Department of Science Teaching at the Weizmann Institute of Science, Israel. The project's general goal was to teach chemistry concepts in the…

  7. Teaching-as-Research Internships: A Model for the Development of Future Chemistry Faculty and the Improvement of Teaching in Science, Technology, Engineering, and Math

    Science.gov (United States)

    Gillian-Daniel, Donald L.; Walz, Kenneth A.

    2016-01-01

    Over the past decade, the University of Wisconsin-Madison (UW-Madison) and Madison Area Technical College (Madison College) partnered to create an internship pathway for graduate students pursuing careers as future science, technology, engineering and math (STEM) faculty members. Since 2003, 10 doctoral students from the university completed…

  8. Contribution from philosophy of chemistry to chemistry education: In a case of ionic liquids as technochemistry

    Science.gov (United States)

    Mudzakir, Ahmad; Hernani, Widhiyanti, Tuszie; Sudrajat, Devi Pratiwi

    2017-08-01

    Traditional chemistry education is commonly handing down of concepts, principles, and theories, such as mechanical properties, the relationship between structure and properties as well as chemical structure and chemical bonding theory, to students without engaging them in the processes of chemical inquiry. This practice leads to the lack of opportunity for the students to construct an appropriate understanding of these concepts, principles, and theories. Students are also rarely facilitated in modeling the structure and function of matter themselves. This situation shows that the philosophy of chemistry has not received as much attention from chemistry educators. The main idea of this paper is to embed philosophy of chemistry through the implementation of technochemistry in chemistry education. One of the most interesting and rapidly developing areas of modern chemistry, technologies and engineering is Ionic Liquids (ILs) as an emerging knowledge on technochemistry which can be applied to chemistry education. The developments between academic researchers and industrial developments in the ILs area are conducted in parallel. In order to overcome the existing problems of scientific development in chemistry education, the science and technology of ILs can be used for reconceptualizing the teaching and learning of chemistry to embrace the epistemology in chemistry. This study promises a potential contribution by philosophy of chemistry. The main objectives of this study are to develop: (i) a perspective based on philosophy of science considerations (rational reconstruction) in order to understand ionic liquids and (ii) teaching materials that can be used to enhance pre-service teacher's view of nature of science and technology (VNOST). The method used in the study is analytical-descriptive (elementarization), i.e. the first step in the model of educational reconstruction (MER). This study concludes that the development of the concepts and their applications of ionic

  9. THE FEATURES OF TECHNOLOGICAL UPGRADING OF THE METALLURGICAL ENTERPRISES IN THE REGION DURING IN TERMS OF THE WORLD CRISIS

    Directory of Open Access Journals (Sweden)

    O.A. Romanova

    2009-09-01

    Full Text Available The author examines the major trends and factors of metallurgy development of the region. Features and the need to preserve the taken direction of the innovative development of metallurgy are examined. Priorities of innovation development of metallurgical enterprises in the region in terms of the global financial crisis are proven; among them there are: upgrading and qualitative updating of a large part of the core based on the introduction of energy-saving technologies; expansion of production with high added value; increasing resource efficiency and reducing environmental impact; ensuring high-quality iron-ore raw materials.

  10. Study of improved resins for advanced supersonic technology composites. Part 1: Heteroaromatic polymers containing ether groups. Part 2: Curing chemistry of aromatic polymers and composite studies

    Science.gov (United States)

    Takekoshi, T.; Hillig, W. B.; Mellinger, G. A.

    1975-01-01

    Fourteen ether-containing, aromatic dianhydrides have been synthesized from N-phenyl-3 or 4-nitrophthalimide and various bisphenols. The process involves nucleophilic displacement of activated nitro groups with bisphenolate ions. Ether-containing dianhydrides were indefinitely stable in the presence of atmospheric moisture. One-step, high temperature solution polymerization of the ether-containing dianhydrides with m-phenylene diamine, 4,4'-oxydianiline and 1, 3-bis(4-aminophenoxy)benzene afforded 42 polyetherimides. The polyetherimides were all soluble in m-cresol except two which were found to be crystalline. The glass transition temperatures of the polyetherimides ranged from 178 to 277 C. Soluble polybenzimidazopyrrolones containing ether groups were also prepared from the same ether-containing dianhydrides and aromatic tetraamines by one-step solution polymerization. Using low molecular weight polyetherimides, various thermoset resin systems were developed and tested as matrices for fiber-reinforced composites. The curing chemistry involving reaction of the phthalonitrile group and the o-diaminophenyl group was found to be generally applicable to crosslinking various aromatic polymers other than polyimides.

  11. Capsicum--production, technology, chemistry, and quality. Part V. Impact on physiology, pharmacology, nutrition, and metabolism; structure, pungency, pain, and desensitization sequences.

    Science.gov (United States)

    Govindarajan, V S; Sathyanarayana, M N

    1991-01-01

    The spice Capsicum is the fruit of the cultivated species of the genus Capsicum (family, Solanaceae), C. annuum principally, and C. frutescens L. to a lesser extent. A third variety of C. annuum var. annuum fruits, the large-sized, fleshy bell capsicum is used as a fresh vegetable and valued for its aroma, color, and crisp texture, but with no pungency. This variety is not considered in this series of reviews covering primary processing, production, international trade, chemistry, and biochemistry of functional components--the red keto carotenoids, the aromatic volatiles and the pungent capsaicinoids in Parts I to III. The valid qualitative aspects correlating the specific components of capsicum and their sensory responses are critically covered in Part IV. In this the concluding part of the series of reviews, the significant preference of the spice for initially evoking an aversive response, its potent physiological and pharmacological effects, and the aspects of structure-activity relationships of the pungent stimuli of the capsaicinoids are reviewed. The beneficial effects particularly associated with long usage by some ethnic groups and its safe consumption levels, with a critical review of the studies on the gastrointestinal tract, the cardiovascular system, the sensory system, thermoregulation, nutritional impacts, and an overview of the five series is also detailed.

  12. From Matter to Life:Chemistry?Chemistry!

    Institute of Scientific and Technical Information of China (English)

    Jean-Marie; LEHN

    2007-01-01

    1 Results Animate as well as inanimate matter,living organisms as well as materials,are formed of molecules and of the organized entities resulting from the interaction of molecules with each other.Chemistry provides the bridge between the molecules of inanimate matter and the highly complex molecular architectures and systems which make up living organisms. Synthetic chemistry has developed a very powerful set of methods for constructing ever more complex molecules.Supramolecular chemistry seeks to con...

  13. Green chemistry: A tool in Pharmaceutical Chemistry

    OpenAIRE

    Smita Talaviya; Falguni Majumdar

    2012-01-01

    Green chemistry expresses an area of research developing from scientific discoveries about pollution awareness and it utilizes a set of principles that reduces or eliminates the use or generation of hazardous substances in all steps of particular synthesis or process. Chemists and medicinal scientists can greatly reduce the risk to human health and the environment by following all the valuable principles of green chemistry. The most simple and direct way to apply green chemistry in pharmaceut...

  14. Application of X3D-based virtual reality technology in the education of organic chemistry%基于X3D的虚拟现实技术在有机化学教学中的应用

    Institute of Scientific and Technical Information of China (English)

    吴占凯; 张力

    2011-01-01

    The article analyzes the concept features and classification of the technology of virtual reality, mainly introduces the animation system and interaction mechanism of virtual reality technology based on X3D specification. In this paper, with an instance of electronic transition in organic chemistry,the article describes the methods and procedures for the development of virtual scene with X3D specification in the hope to provide reference for the follow-up development.%分析了虚拟现实技术的概念特征及分类,重点介绍了基于X3D标准的虚拟现实技术中的动画机制及交互机制.结合有机化学中电子跃迁实例,阐述了运用X3D标准开发虚拟场景的方法与步骤,以期对后续的开发工作起到借鉴作用.

  15. Environmental control technology survey of selected US strip mining sites. Volume 2A: Ohio: water quality impacts and overburden chemistry of Ohio study site

    Energy Technology Data Exchange (ETDEWEB)

    Bogner, J E; Henricks, J D; Olsen, R D; Schubert, J P; Sobek, A A; Wilkey, M L; Johnson, D O

    1979-05-01

    An intensive study of water, overburden, and coal chemistry was conducted at a large surface mine in Ohio from May 1976 through July 1977. Sampling sites were chosen to include the final mine effluent at the outflow of a large settling pond and chemically-treated drainage from a coal storage pile. Samples were collected semimonthly and analyzed for total dissolved solids, total suspended solids, alkalinity, acidity, sulfate, chloride, and 16 metals. Field measurements included pH, flow rate, dissolved oxygen, and specific conductance. The final effluent, where sampled, generally complied with Office of Surface Mining reclamation standards for pH, iron, and total suspended solids. Comparison of the final effluent with water quality of an unnamed tributary above the mine suggested that elevated values for specific conductance, total dissolved solids, sulfate, calcium, magnesium, manganese, and zinc were attributable to the mine operation. In general, there were observable seasonal variations in flow rates that correlated positively to suspended solids concentrations and negatively to concentrations of dissolved constituents in the final effluent. Drainage from the coal storage pile contained elevated levels of acidity and dissolved metals which were not reduced significantly by the soda ash treatment. The storage pile drainage was diluted, however, by large volumes of alkaline water in the settling pond. Analysis of overburden and coal indicated that the major impact of mine drainage was pyrite oxidation and hydrolysis in the Middle Kittanning Coal and in the Lower Freeport Shale overlying the coal. However, the presence of a calcite-cemented section in the Upper Freeport Sandstone contributed substantial self-neutralizing capacity to the overburden section, resulting in generally alkaline drainage at this site.

  16. Environmental control technology survey of selected US strip mining sites. Volume 2A: Ohio: water quality impacts and overburden chemistry of Ohio study site

    Energy Technology Data Exchange (ETDEWEB)

    Bogner, J E; Henricks, J D; Olsen, R D; Schubert, J P; Sobek, A A; Wilkey, M L; Johnson, D O

    1979-05-01

    An intensive study of water, overburden, and coal chemistry was conducted at a large surface mine in Ohio from May 1976 through July 1977. Sampling sites were chosen to include the final mine effluent at the outflow of a large settling pond and chemically-treated drainage from a coal storage pile. Samples were collected semimonthly and analyzed for total dissolved solids, total suspended solids, alkalinity, acidity, sulfate, chloride, and 16 metals. Field measurements included pH, flow rate, dissolved oxygen, and specific conductance. The final effluent, where sampled, generally complied with Office of Surface Mining reclamation standards for pH, iron, and total suspended solids. Comparison of the final effluent with water quality of an unnamed tributary above the mine suggested that elevated values for specific conductance, total dissolved solids, sulfate, calcium, magnesium, manganese, and zinc were attributable to the mine operation. In general, there were observable seasonal variations in flow rates that correlated positively to suspended solids concentrations and negatively to concentrations of dissolved constituents in the final effluent. Drainage from the coal storage pile contained elevated levels of acidity and dissolved metals which were not reduced significantly by the soda ash treatment. The storage pile drainage was diluted, however, by large volumes of alkaline water in the settling pond. Analysis of overburden and coal indicated that the major impact of mine drainage was pyrite oxidation and hydrolysis in the Middle Kittanning Coal and in the Lower Freeport Shale overlying the coal. However, the presence of a calcite-cemented section in the Upper Freeport Sandstone contributed substantial self-neutralizing capacity to the overburden section, resulting in generally alkaline drainage at this site.

  17. Physics and Chemistry of Interfaces

    CERN Document Server

    Butt, Hans-Jurgen; Kappl, Michael

    2003-01-01

    Serving as a general introduction to surface and interface science, this book focuses on essential concepts rather than specific details, on intuitive understanding rather than learning facts. The text reflects the fact that the physics and chemistry of surfaces is a diverse field of research and shows this in its Interdisciplinary conceptual design. Once the most important techniques and methods have been introduced, readers will be able to apply simple models to their own scientific problems. Furthermore, manifold high-end technological applications from surface technology, biotechnology, or

  18. Constitutional dynamic chemistry: bridge from supramolecular chemistry to adaptive chemistry.

    Science.gov (United States)

    Lehn, Jean-Marie

    2012-01-01

    Supramolecular chemistry aims at implementing highly complex chemical systems from molecular components held together by non-covalent intermolecular forces and effecting molecular recognition, catalysis and transport processes. A further step consists in the investigation of chemical systems undergoing self-organization, i.e. systems capable of spontaneously generating well-defined functional supramolecular architectures by self-assembly from their components, thus behaving as programmed chemical systems. Supramolecular chemistry is intrinsically a dynamic chemistry in view of the lability of the interactions connecting the molecular components of a supramolecular entity and the resulting ability of supramolecular species to exchange their constituents. The same holds for molecular chemistry when the molecular entity contains covalent bonds that may form and break reversibility, so as to allow a continuous change in constitution by reorganization and exchange of building blocks. These features define a Constitutional Dynamic Chemistry (CDC) on both the molecular and supramolecular levels.CDC introduces a paradigm shift with respect to constitutionally static chemistry. The latter relies on design for the generation of a target entity, whereas CDC takes advantage of dynamic diversity to allow variation and selection. The implementation of selection in chemistry introduces a fundamental change in outlook. Whereas self-organization by design strives to achieve full control over the output molecular or supramolecular entity by explicit programming, self-organization with selection operates on dynamic constitutional diversity in response to either internal or external factors to achieve adaptation.The merging of the features: -information and programmability, -dynamics and reversibility, -constitution and structural diversity, points to the emergence of adaptive and evolutive chemistry, towards a chemistry of complex matter.

  19. The role of water in unconventional in situ energy resource extraction technologies: Chapter 7 in Food, energy, and water: The chemistry connection

    Science.gov (United States)

    Gallegos, Tanya J.; Bern, Carleton R.; Birdwell, Justin E.; Haines, Seth S.; Engle, Mark A.

    2015-01-01

    Global trends toward developing new energy resources from lower grade, larger tonnage deposits that are not generally accessible using “conventional” extraction methods involve variations of subsurface in situ extraction techniques including in situ oil-shale retorting, hydraulic fracturing of petroleum reservoirs, and in situ recovery (ISR) of uranium. Although these methods are economically feasible and perhaps result in a smaller above-ground land-use footprint, there remain uncertainties regarding potential subsurface impacts to groundwater. This chapter provides an overview of the role of water in these technologies and the opportunities and challenges for water reuse and recycling.

  20. CHINESE JOURNAL OF CHEMISTRY

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@Chinese Journal of Chemistry is an international journal published in English by the Chinese Chemical Society with its editorial office hosted by Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences.

  1. Advanced Chemistry Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Description/History: Chemistry laboratoryThe Advanced Chemistry Laboratory (ACL) is a unique facility designed for working with the most super toxic compounds known...

  2. Organometallic Chemistry of Molybdenum.

    Science.gov (United States)

    Lucas, C. Robert; Walsh, Kelly A.

    1987-01-01

    Suggests ways to avoid some of the problems students have learning the principles of organometallic chemistry. Provides a description of an experiment used in a third-year college chemistry laboratory on molybdenum. (TW)

  3. Environmental chemistry: Volume A

    Energy Technology Data Exchange (ETDEWEB)

    Yen, T.F.

    1999-08-01

    This is an extensive introduction to environmental chemistry for engineering and chemical professionals. The contents of Volume A include a brief review of basic chemistry prior to coverage of litho, atmo, hydro, pedo, and biospheres.

  4. Chemistry for Potters.

    Science.gov (United States)

    Denio, Allen A.

    1980-01-01

    Relates pottery making to chemistry by providing chemical information about clay, its origin, composition, properties, and changes that occur during firing; also describes glaze compositions, examples of redox chemistry, salt glazing, crystalline glazes, and problems in toxicity. (CS)

  5. Green chemistry: A tool in Pharmaceutical Chemistry

    Directory of Open Access Journals (Sweden)

    Smita Talaviya

    2012-07-01

    Full Text Available Green chemistry expresses an area of research developing from scientific discoveries about pollution awareness and it utilizes a set of principles that reduces or eliminates the use or generation of hazardous substances in all steps of particular synthesis or process. Chemists and medicinal scientists can greatly reduce the risk to human health and the environment by following all the valuable principles of green chemistry. The most simple and direct way to apply green chemistry in pharmaceuticals is to utilize eco-friendly, non-hazardous, reproducible and efficient solvents and catalysts in synthesis of drug molecules, drug intermediates and in researches involving synthetic chemistry. Microwave synthesis is also an important tool of green chemistry by being an energy efficient process.

  6. Synthesis of Carbon Nanotube-Reinforced Al2024 Matrix Nanocomposite Using Flake Powder Metallurgy Method

    Science.gov (United States)

    Rikhtegar, F.; Shabestari, S. G.; Saghafian, H.

    2016-12-01

    In current work, the flake powder metallurgy method was applied to achieve the uniform dispersion of carbon nanotubes (CNTs) within the Al2024 powder. For this purpose, the flake morphology of Al2024 powder with suitable diameter-to-thickness ratio ( D/ t = 85) was obtained after ball milling for 4 hours at 250 rpm and ball-to-powder ratio = 10. Then, the surface of matrix was modified by a hydrophilic polymer [polyvinyl alcohol (PVA)] to obtain the sufficient -OH group on its surface. Additionally, the refluxing of CNTs in nitric acid was performed at 393 K (120 °C) for 6 hours to functionalize the reinforcement by -COOH agent. After preparation of initial materials, the Al2024-1.5 wt pct CNTs suspension was stirred in a slurry at pH 3 until the color was changed in steady state from ink-like to transparent at pH 5. The hydrogen bonding was formed between the -OH groups of PVA coated Al2024 and -COOH groups of functionalized MWCNTs during the mixing step. Also, the temporary polarity could be considered between H+ and {{{C}}_{12}}{{{H}}_{25}}{{SO}}_4^ - ions on the surface of constituents, which led to improvement in the CNT distribution due to the changing of suspension pH. Consequently, the homogenous dispersion of CNTs in Al2024 flaky powders resulted in a chemical reaction of constituents without any destructive effects of mechanical forces. The morphological changes of Al2024 powders were studied by scanning electron microscopy (SEM), and surface treatments were evaluated by Fourier transform infrared and Raman spectroscopies. The dispersion of nanocomposite powder was investigated through field emission SEM. Also, X-ray diffraction analysis was used to investigate the initial Al2024 powder and formed phases after the ball milling process.

  7. Interfacial reactions and wetting in Al-Mg sintered by powder metallurgy process

    Science.gov (United States)

    Faisal, Heny; Darminto, Triwikantoro, Zainuri, M.

    2016-04-01

    Was conducted to analyze the effect of temperature variation on the bonding interface sintered composite Al-Mg and analyze the effect of variations of the density and hardness sinter. Research carried out by the base material powders of Al, Mg powder and solvent n-butanol. The method used in this study is a powder metallurgy, with a composition of 60% volume fraction of Al - 40% Mg. Al-Mg mixing with n-butanol for 1 hour at 500 rpm. Then the emphasis (cold comression) with a size of 1.4 cm in diameter dies and height of 2.8 cm, is pressed with a force of 20 MPa and held for 15 minutes. After the sample into pellets, then sintered at various temperatures 300 °C, 350 °C, 400 °C and 450 °C. Characterization is done by using the testing green density, sintered density, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), vickers microhardness, and press test. XRD data analysis done by using X'Pert High Score Plus (HSP) to determine whether there is a new phase is formed. Test results show that the sintered density increasing sintering temperature, the resulting density is also increasing (shrinkage). However, at a temperature of 450 °C decreased (swelling). With the increased sinter density, interfacial bonding getting Kuta and more compact so that its hardness is also increased. From the test results of SEM / EDX, there Mg into Al in the border area. At temperatures of 300 °C, 350 °C, 400 °C, the phase formed is Al, Mg and MgO. While phase is formed at a temperature of 450 °C is aluminum magnesium (Al3Mg2), Aluminum Magnesium Zinc (AlMg2Zn).

  8. Mg-Zn based composites reinforced with bioactive glass (45S5) fabricated via powder metallurgy

    Science.gov (United States)

    Ab llah, N.; Jamaludin, S. B.; Daud, Z. C.; Zaludin, M. A. F.

    2016-07-01

    Metallic implants are shifting from bio-inert to bioactive and biodegradable materials. These changes are made in order to improve the stress shielding effect and bio-compatibility and also avoid the second surgery procedure. Second surgery procedure is required if the patient experienced infection and implant loosening. An implant is predicted to be well for 15 to 20 years inside patient body. Currently, magnesium alloys are found to be the new biomaterials because of their properties close to the human bones and also able to degrade in the human body. In this work, magnesium-zinc based composites reinforced with different content (5, 15, 20 wt. %) of bioactive glass (45S5) were fabricated through powder metallurgy technique. The composites were sintered at 450˚C. Density and porosity of the composites were determined using the gas pycnometer. Microstructure of the composites was observed using an optical microscope. In-vitro bioactivity behavior was evaluated in the simulated body fluid (SBF) for 7 days. Fourier Transform Infrared (FTIR) was used to characterize the apatite forming on the samples surface. The microstructure of the composite showed that the pore segregated near the grain boundaries and bioglass clustering was observed with increasing content of bioglass. The true density of the composites increased with the increasing content of bioglass and the highest value of porosity was indicated by the Mg-Zn reinforced with 20 wt.% of bioglass. The addition of bio-glass to the Mg-Zn has also induced the formation of apatite layer after soaking in SBF solution.

  9. Microstructure and Mechanical Properties of Ti-Mo-Zr-Cr Biomedical Alloys by Powder Metallurgy

    Science.gov (United States)

    Elshalakany, Abou Bakr; Ali, Shady; Amigó Mata, A.; Eessaa, Ashraf K.; Mohan, P.; Osman, T. A.; Amigó Borrás, V.

    2017-03-01

    Titanium and its alloys have been widely used as biometals due to their excellent biocompatibility, corrosion resistance and moderate mechanical properties. Ti-15Mo-6Zr-based alloys and a series of Ti-15Mo-6Zr-xCr ( x = 1, 2, 3, 4 wt.%) alloys were designed and fabricated by powder metallurgy for the first time to develop novel biomedical materials. The microstructure, internal porosity and mechanical properties of the sintered Ti-15Mo-6Zr and Ti-15Mo-6Zr-xCr alloys were investigated using scanning electronic microscopy (SEM) and bending and compression tests. The experimental results indicated that the microstructure and mechanical properties of these alloys changed as different Cr levels were added. The addition of small Cr levels further increased the β-phase stability, improving the properties of the Ti-15Mo-6Zr-xCr alloy. However, all of the alloys had good ductility, and the Ti-15Mo-6Zr-2Cr alloy had lower bending and compression moduli (31 and 23 GPa, respectively) than the Ti-15Mo-6Zr-based alloys (40 and 36 GPa, respectively). Moreover, the Ti-15Mo-6Zr-2Cr alloys exhibited higher bending and compression strength/modulus ratios, which were as large as 48.4 and 52.2, respectively; these were higher than those of the Ti-15Mo-6Zr-based alloy (41.3 and 33.6, respectively). In the search for a better implant material, β phase Ti-15Mo-6Zr-2Cr, with its low modulus, ductile properties and reasonably high strength, is a promising candidate.

  10. In vitro degradation and cytotoxicity of Mg/Ca composites produced by powder metallurgy.

    Science.gov (United States)

    Zheng, Y F; Gu, X N; Xi, Y L; Chai, D L

    2010-05-01

    Mg/Ca (1 wt.%, 5 wt.%, 10 wt.% Ca) composites were prepared from pure magnesium and calcium powders using the powder metallurgy method, aiming to enlarge the addition of Ca content without the formation of Mg(2)Ca. The microstructures, mechanical properties and cytotoxicities of Mg/Ca composite samples were investigated. The corrosion of Mg/Ca composites in Dulbecco's modified Eagle's medium (DMEM) for various immersion intervals was studied by electrochemical impedance spectroscopy measurements and environmental scanning electron microscope, with the concentrations of released Mg and Ca ions in DMEM for various immersion time intervals being measured. It was shown that the main constitutional phases were Mg and Ca, which were uniformly distributed in the Mg matrix. The ultimate tensile strength (UTS) and elongation of experimental composites decreased with increasing Ca content, and the UTS of Mg/1Ca composite was comparable with that of as-extruded Mg-1Ca alloy. The corrosion potential increased with increasing Ca content, whereas the current density and the impedance decreased. It was found that the protective surface film formed quickly at the initial immersion stage. With increasing immersion time, the surface film became compact, and the corrosion rate of Mg/Ca composites slowed down. The surface film consisted mainly of CaCO(3), MgCO(3)x3H(2)O, HA and Mg(OH)(2) after 72 h immersion in DMEM. Mg/1Ca and Mg/5Ca composite extracts had no significant toxicity (p>0.05) to L-929 cells, whereas Mg/10Ca composite extract induced approximately 40% reduced cell viability.

  11. Interfacial metallurgy study of brazed joints between tungsten and fusion related materials for divertor design

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yuxuan, E-mail: yuxuan.zhang@strath.ac.uk [Department of Mechanical and Aerospace Engineering, University of Strathclyde, Glasgow G1 1XJ (United Kingdom); Galloway, Alexander; Wood, James; Robbie, Mikael Brian Olsson; Easton, David [Department of Mechanical and Aerospace Engineering, University of Strathclyde, Glasgow G1 1XJ (United Kingdom); Zhu, Wenzhong [School of Engineering, University of the West of Scotland, Paisley PA1 2BE (United Kingdom)

    2014-11-15

    Highlights: • We created brazed joints between tungsten and EUROFER 97, Cu and SS316L with Au80Cu19Fe1 filler. • No elemental transitions were detected between the W and the AuCuFe filler in either direction. • Transition regions between filler to EUROFER97/316L showed similar elastic modulus and hardness to the filler. • Smooth elemental and mechanical properties transition were detected between the filler and Cu. - Abstract: In the developing DEMO divertor, the design of joints between tungsten to other fusion related materials is a significant challenge as a result of the dissimilar physical metallurgy of the materials to be joined. This paper focuses on the design and fabrication of dissimilar brazed joints between tungsten and fusion relevant materials such as EUROFER 97, oxygen-free high thermal conductivity (OFHC) Cu and SS316L using a gold based brazing foil. The main objectives are to develop acceptable brazing procedures for dissimilar joining of tungsten to other fusion compliant materials and to advance the metallurgical understanding within the interfacial region of the brazed joint. Four different butt-type brazed joints were created and characterised, each of which were joined with the aid of a thin brazing foil (Au80Cu19Fe1, in wt.%). Microstructural characterisation and elemental mapping in the transition region of the joint was undertaken and, thereafter, the results were analysed as was the interfacial diffusion characteristics of each material combination produced. Nano-indentation tests are performed at the joint regions and correlated with element composition information in order to understand the effects of diffused elements on mechanical properties. The experimental procedures of specimen fabrication and material characterisation methods are presented. The results of elemental transitions after brazing are reported. Elastic modulus and nano-hardness of each brazed joints are reported.

  12. SYNTHESIS OF NANO-ZnO PARTICLES FOR ALUMINUM METALLURGY AS INERT ANODE MATERIAL

    Institute of Scientific and Technical Information of China (English)

    A.A.A. Saleh; Y. Fu; X.J. Zhai; Y.C. Zhai; M.M. Elomella; A.L. Zhang

    2004-01-01

    Nano-ZnO particle was produced by evaporating zinc powders in air at air flow-rate from 0.2 to 0.6m3/h. Nano-ZnO particles was formed by the oxidation of the evaporated zinc vapor. X-ray diffraction shows the powders to be ZnO with lattice parameters of a=0.3249nm and c=0.5205nm. The particle size is dependent upon the transit time from the source to the collection area. The size of particles was ranged between 81 to 103nm. The average density resulted was 4.865g/cm3.Normal ZnO and nano-ZnO were investigated to use them in aluminum metallurgy as an inert anode material. A certain amount of both oxides were molded subsequently inserted to the molten cryolite-aluminum oxide to investigate the corrosive behavior of both oxides. When the sintering temperature increased up to 1300 ℃, the weight loss ratio rose to 5.01%-7.33% and up to 7.67%-10.18% for nano-ZnO and normal ZnO, respectively. However, when the samples in the molten cryolite aluminum oxide were put for long time, the corrosive rate was found to be higher. It was found that the corrosive loss weight ratio of nano-ZnO anode was much lower than the normal one made from ordinary-ZnO providing that the nano-ZnO is more possible to be use inert anode material.

  13. Sputtered Ni-Zn under bump metallurgy (UBM) for Sn-Ag-Cu solders

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Jin; Kim, Young Min [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Kim, Young-Ho, E-mail: kimyh@hanyang.ac.kr [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer Ni-Zn UBM can effectively suppress the growth of IMCs and the consumption of UBM. Black-Right-Pointing-Pointer The growth of (Ni, Cu){sub 3}Sn{sub 4} was retarded at the SAC305/Ni-Zn interface after aging. Black-Right-Pointing-Pointer Only a single (Cu, Ni){sub 6}Sn{sub 5} formed at the SAC107/Ni-Zn interface after aging. Black-Right-Pointing-Pointer Segregated Zn atoms on IMC layers retarded the interdiffusion of Cu, Ni, and Sn. Black-Right-Pointing-Pointer Sputtered Ni-Zn UBM is promising for Pb-free solder flip chip applications. - Abstract: We developed a new sputtered under bump metallurgy (UBM) based on Ni-20wt% Zn thin films for Pb-free solders. This study focuses on the interfacial reactions between two Pb-free solders (Sn3.0Ag0.5Cu and Sn1.0Ag0.7Cu) and a Ni-Zn alloy UBM. By adding Zn to Ni UBM, Zn is incorporated into intermetallic compounds (IMCs) to form a quaternary Cu-Ni-Zn-Sn phase at the solder/Ni-Zn interface after reflow and subsequent isothermal aging. The Ni-Zn UBM sufficiently reduces the interfacial reaction and IMCs formation rates as well as UBM consumption rates compared to a Ni UBM. In particular, the formation of (Ni, Cu){sub 3}Sn{sub 4} IMC was significantly retarded by adding Zn into UBM.

  14. Organic chemistry experiment

    Energy Technology Data Exchange (ETDEWEB)

    Mun, Seok Sik

    2005-02-15

    This book deals with organic chemistry experiments, it is divided five chapters, which have introduction, the way to write the experiment report and safety in the laboratory, basic experiment technic like recrystallization and extraction, a lot of organic chemistry experiments such as fischer esterification, ester hydrolysis, electrophilic aromatic substitution, aldol reaction, benzoin condensation, wittig reaction grignard reaction, epoxidation reaction and selective reduction. The last chapter introduces chemistry site on the internet and way to find out reference on chemistry.

  15. American Association for Clinical Chemistry

    Science.gov (United States)

    ... older adolescents and adults. Read more IN CLINICAL CHEMISTRY Eliminating Wild-Type DNA in Liquid Biopsies Researchers ... Online Harmonization.net Commission on Accreditation in Clinical Chemistry American Board of Clinical Chemistry Clinical Chemistry Trainee ...

  16. Green Chemistry and Education.

    Science.gov (United States)

    Hjeresen, Dennis L.; Schutt, David L.; Boese, Janet M.

    2000-01-01

    Many students today are profoundly interested in the sustainability of their world. Introduces Green Chemistry and its principles with teaching materials. Green Chemistry is the use of chemistry for pollution prevention and the design of chemical products and processes that are environmentally benign. (ASK)

  17. Chemistry and Art.

    Science.gov (United States)

    Berry, Martyn

    1999-01-01

    Describes a Chemistry and Art project developed for secondary students and teachers sponsored by the National Gallery and The Royal Society of Chemistry in the United Kingdom. Discusses aspects of the techniques used in creating five paintings as well as the chemistry involved in their making, deterioration, conservation, and restoration.…

  18. Green Chemistry and Education.

    Science.gov (United States)

    Hjeresen, Dennis L.; Schutt, David L.; Boese, Janet M.

    2000-01-01

    Many students today are profoundly interested in the sustainability of their world. Introduces Green Chemistry and its principles with teaching materials. Green Chemistry is the use of chemistry for pollution prevention and the design of chemical products and processes that are environmentally benign. (ASK)

  19. Physical chemistry of surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, A.

    1990-01-01

    This book covers surface chemistry and selected aspects f colloid chemistry. The text covers such areas as structure and thermodynamics of liquid interfaces; electrical aspects of surface chemistry; microscopy and spectroscopy of solid interfaces; nucleation; contact angle; adsorption from solution; friction and adhesion; lubrication; and chemisorption and catalysis.

  20. Early atmospheric metal pollution provides evidence for Chalcolithic/Bronze Age mining and metallurgy in Southwestern Europe

    Energy Technology Data Exchange (ETDEWEB)

    Martínez Cortizas, Antonio, E-mail: antonio.martinez.cortizas@usc.es [Departamento de Edafoloxía e Química Agrícola, Facultade de Bioloxía, Universidade de Santiago de Compostela, Campus Sur s/n, Santiago de Compostela (Spain); López-Merino, Lourdes, E-mail: lourdes.lopez-merino@brunel.ac.uk [Institute of Environment, Health and Societies, Brunel University London, UB8 3PH Uxbridge (United Kingdom); Bindler, Richard, E-mail: richard.bindler@umu.se [Department of Ecology and Environmental Science, Umeå University, Umeå (Sweden); Mighall, Tim, E-mail: t.mighall@abdn.ac.uk [Department of Geography & Environment, School of Geosciences, University of Aberdeen, Elphinstone Road, Aberdeen AB24 3UF (United Kingdom); Kylander, Malin E., E-mail: malin.kylander@geo.su.se [Department of Geological Sciences and the Bolin Centre for Climate Research, Stockholm University, SE-10691, Stockholm (Sweden)

    2016-03-01

    Although archaeological research suggests that mining/metallurgy already started in the Chalcolithic (3rd millennium BC), the earliest atmospheric metal pollution in SW Europe has thus far been dated to ~ 3500–3200 cal. yr. BP in paleo-environmental archives. A low intensity, non-extensive mining/metallurgy and the lack of appropriately located archives may be responsible for this mismatch. We have analysed the older section (> 2100 cal. yr. BP) of a peat record from La Molina (Asturias, Spain), a mire located in the proximity (35–100 km) of mines which were exploited in the Chalcolithic/Bronze Age, with the aim of assessing evidence of this early mining/metallurgy. Analyses included the determination of C as a proxy for organic matter content, lithogenic elements (Si, Al, Ti) as markers of mineral matter, and trace metals (Cr, Cu, Zn, Pb) and stable Pb isotopes as tracers of atmospheric metal pollution. From ~ 8000 to ~ 4980 cal. yr. BP the Pb composition is similar to that of the underlying sediments (Pb 15 ± 4 μg g{sup −1}; {sup 206}Pb/{sup 207}Pb 1.204 ± 0.002). A sustained period of low {sup 206}Pb/{sup 207}Pb ratios occurred from ~ 4980 to ~ 2470 cal. yr. BP, which can be divided into four phases: Chalcolithic (~ 4980–3700 cal. yr. BP), {sup 206}Pb/{sup 207}Pb ratios decline to 1.175 and Pb/Al ratios increase; Early Bronze Age (~ 3700–3500 cal. yr. BP), {sup 206}Pb/{sup 207}Pb increase to 1.192 and metal/Al ratios remain stable; Late Bronze Age (~ 3500–2800 cal. yr. BP), {sup 206}Pb/{sup 207}Pb decline to their lowest values (1.167) while Pb/Al and Zn/Al increase; and Early Iron Age (~ 2800–2470 cal. yr. BP), {sup 206}Pb/{sup 207}Pb increase to 1.186, most metal/Al ratios decrease but Zn/Al shows a peak. At the beginning of the Late Iron Age, {sup 206}Pb/{sup 207}Pb ratios and metal enrichments show a rapid return to pre-anthropogenic values. These results provide evidence of regional/local atmospheric metal pollution triggered by the