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Sample records for fr07se10n aluminum extrusions

  1. 75 FR 80527 - Aluminum Extrusions From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-22

    ... Affirmative Countervailing Duty Determination, 75 FR 54302, September 7, 2010, and Aluminum Extrusions From... Antidumping Duty Determination, 75 FR 57441, September 21, 2010. \\3\\ See Aluminum Extrusions From the People's... Determination of Targeted Dumping, 75 FR 69403, November 12, 2010, and Aluminum Extrusions From the...

  2. Etching Behavior of Aluminum Alloy Extrusions

    NASA Astrophysics Data System (ADS)

    Zhu, Hanliang

    2014-11-01

    The etching treatment is an important process step in influencing the surface quality of anodized aluminum alloy extrusions. The aim of etching is to produce a homogeneously matte surface. However, in the etching process, further surface imperfections can be generated on the extrusion surface due to uneven materials loss from different microstructural components. These surface imperfections formed prior to anodizing can significantly influence the surface quality of the final anodized extrusion products. In this article, various factors that influence the materials loss during alkaline etching of aluminum alloy extrusions are investigated. The influencing variables considered include etching process parameters, Fe-rich particles, Mg-Si precipitates, and extrusion profiles. This study provides a basis for improving the surface quality in industrial extrusion products by optimizing various process parameters.

  3. 75 FR 34482 - Certain Aluminum Extrusions From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-17

    ... Commission, Washington, DC, and by publishing the notice in the Federal Register of April 6, 2010 (75 FR... COMMISSION Certain Aluminum Extrusions From China Determinations On the basis of the record \\1\\ developed in... reason of imports from China of certain aluminum extrusions, provided for in subheadings 7604.21,...

  4. Effect of Extrusion Profile on Surface Microstructure and Appearance of Aluminum Extrusions with Different Fe Contents

    NASA Astrophysics Data System (ADS)

    Zhu, Hanliang; Wei, Tao; Couper, Malcolm J.; Dahle, Arne K.

    2013-05-01

    Aluminum alloy extrusions with variations in profiles and Fe-rich particles were produced using different extrusion dies and iron contents. A microstructural examination of the extrusion surface shows that the extrusion profile and iron content have a great effect on the size and number of Fe-rich particles, grain size, texture, and fraction of high-angle grain boundaries due to varying localized plastic deformation and temperature in the extrudate. After etching and anodizing, surface imperfections such as grain boundary grooves that influence the final surface appearance are formed on the extrusion surfaces. The severity of grain boundary grooves is found to be directly linked to the number of Fe-rich particles. Hence, the extrusion profile has a dramatic influence on surface imperfections and the appearance of the final anodized extrusions through its effect on the surface microstructure.

  5. Reducing the Surface Degradation of Aluminum Extrusion Dies During Preheating

    NASA Astrophysics Data System (ADS)

    Stratton, Paul

    2010-07-01

    Aluminum extrusion dies are usually made from H13 steel that is ferritically nitrocarburized to minimize wear and pick-up. Before being placed in the extrusion press, the dies are preheated to minimize thermal shock at the start of the extrusion cycle. During the preheating time, the nitrocarburized layer oxidizes. Some of this layer can break away during extrusion leaving marks on the product. Although inerting the preheat furnaces with nitrogen has been found to reduce the oxidation, it does not solve the problem completely. Experiments have shown that a small addition of ammonia to the preheating protective atmosphere could eliminate oxidation and prevent nitrogen loss from the surface nitride layer.

  6. 75 FR 34982 - Aluminum Extrusions from the People's Republic of China: Notice of Postponement of Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-21

    ... countervailing duty investigation of aluminum extrusions from the People's Republic of China. See Aluminum Extrusions From the People's Republic of China: Initiation of Countervailing Duty Investigation, 75 FR 22114... International Trade Administration Aluminum Extrusions from the People's Republic of China: Notice...

  7. 76 FR 29007 - Certain Aluminum Extrusions From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-19

    ... in the Federal Register on December 22, 2010 (75 FR 80527). The hearing was held in Washington, DC... certain aluminum extrusions from ] China other than finished heat sinks, provided for in subheadings 7604... industry in the United States is not materially retarded, by reason of imports of finished heat sinks...

  8. 75 FR 17436 - Certain Aluminum Extrusions From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-06

    ... amended, 67 FR 68036 (November 8, 2002). Even where electronic filing of a document is permitted, certain... Electronic Filing Procedures, 67 FR 68168, 68173 (November 8, 2002). In accordance with sections 201.16(c... COMMISSION Certain Aluminum Extrusions From China AGENCY: United States International Trade...

  9. 77 FR 54900 - Aluminum Extrusions From the People's Republic of China: Final Results of Changed Circumstances...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-06

    ... Extrusions from the People's Republic of China: Preliminary Results of Changed Circumstances Review, 77 FR... Determination of Sales at Less Than Fair Value, 76 FR 18524 (April 4, 2011); see also Aluminum Extrusions From... Fair Value, 76 FR 20627 (April 13, 2011). \\3\\ Id. \\4\\ See Aluminum Extrusions from the...

  10. 75 FR 51243 - Aluminum Extrusions from the People's Republic of China: Postponement of Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-19

    ...: Initiation of Antidumping Duty Investigation, 75 FR 22109 (April 27, 2010). On August 4, 2010, the Aluminum... International Trade Administration Aluminum Extrusions from the People's Republic of China: Postponement of... antidumping duty investigation on Aluminum Extrusions from the People's Republic of China.\\1\\ The notice...

  11. Extrusion strains produced in cast and in powder aluminum billets

    SciTech Connect

    Peacock, H B; Berghaus, D G

    1986-01-01

    A full-field solution for strains produced during axisymmetric extrusion may be obtained through a study of laminar flowlines which are produced as the material flows through the die. A flow function is mathematically constructed, using the flowlines, to determine the material flow rate along the given path. Velocities and strain-rates are determined along the flowlines. Flowline curves are determined experimentally from the stamped rectangular grid which was originally placed on an axial plane in a pre-extruded billet. For the powder metal billet, density values must also be determined experimentally. The method has been applied to the axisymmetric extrusion of cast and powder aluminum billets. Material deformation was studied for the powdered metal billet using the Scanning Electron Microscope.

  12. 78 FR 51143 - Aluminum Extrusions From the People's Republic of China: Initiation of Changed Circumstances...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-20

    ... Aluminum Extrusions from the People's Republic of China: Antidumping Duty Order, 76 FR 30650 (May 26, 2011) and Aluminum Extrusions From the People's Republic of China: Countervailing Duty Order, 76 FR 30653..., electrical conduits, door thresholds, carpet trim, or heat sinks (that do not meet the finished heat...

  13. 78 FR 34984 - Aluminum Extrusions From the People's Republic of China: Notice of Court Decision Not in Harmony...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-11

    ... Aluminum Extrusions from the People's Republic of China: Antidumping Duty Order, 76 FR 30650 (May 26, 2011) and Aluminum Extrusions from the People's Republic of China: Countervailing Duty Order, 76 FR 30653... International Trade Administration Aluminum Extrusions From the People's Republic of China: Notice of...

  14. Strain fields for aluminum at different tooling temperatures and extrusion ratios

    SciTech Connect

    Peacock, H.B.; Berghaus, D.G.

    1985-03-01

    Strain distributions throughout the die region are obtained for axisymmetric extrusion of aluminum billets. Results which include the three extensional strains and accumulated shear are produced from an analysis of experimentally obtained laminar flow lines on extruded specimens. Extrusion experiments are performed at average tooling temperatures of 174/sup 0/C and 354/sup 0/C and for extrusion ratios from 1.9 to 12.4. Both tooling temperatures and extrusion ratios affect the magnitude and/or the distribution of plastic strains in extruded aluminum.

  15. High cycle fatigue of AA6082 and AA6063 aluminum extrusions

    NASA Astrophysics Data System (ADS)

    Nanninga, Nicholas E.

    The high cycle fatigue behavior of hollow extruded AA6082 and AA6063 aluminum extrusions has been studied. Hollow extruded aluminum profiles can be processed into intricate shapes, and may be suitable replacements for fatigue critical automotive applications requiring reduced weight. There are several features inherent in hollow aluminum extrusions, such as seam welds, charge welds, microstructural variations and die lines. The effects of such extrusion variables on high cycle fatigue properties were studied by taking specimens from an actual car bumper extrusion. It appears that extrusion die lines create large anisotropy differences in fatigue properties, while welds themselves have little effect on fatigue lives. Removal of die lines greatly increased fatigue properties of AA6082 specimens taken transverse to the extrusion direction. Without die lines, anisotropy in fatigue properties between AA6082 specimens taken longitudinal and transverse to the extrusion direction, was significantly reduced, and properties associated with the orientation of the microstructure appears to be isotropic. A fibrous microstructure for AA6082 specimens showed great improvements in fatigue behavior. The effects of elevated temperatures and exposure of specimens to NaCl solutions was also studied. Exposure to the salt solution greatly reduced the fatigue lives of specimens, while elevated temperatures showed more moderate reductions in fatigue lives.

  16. Study on extrusion of aluminum microchannel flat tube

    NASA Astrophysics Data System (ADS)

    Tang, Ding; Zhang, Qingqing; Li, Dayong; Peng, Yinghong

    2013-05-01

    Micro-channel tube with submillimeter-diameter channels is a kind of newly developed heat transferring tube. As the micro-channel tube has many welding points and works under high pressure condition, welding strength is one of the key issues for its extrusion process. This paper presented a new study on evaluation of the seam welding strength formed in the extrusion process. Firstly, FE simulation is carried out for the status of the billet in the welding chamber during the extrusion process. Then, thermo mechanical experiment is done to study the relationship between the welding strength and key factors. The welding process is characterized as the void evolution on the welding interface, which consists of void generation, void cohesion and void closure. Combining the relationship with the numerical results, welding strength of the micro-channel tube can be evaluated. The extrusion die is developed and the microchannel tube is successfully extruded. The study is helpful for the optimization the extrusion process and improvement of the seam weld quality.

  17. Nitriding of Aluminum Extrusion Die: Effect of Die Geometry

    NASA Astrophysics Data System (ADS)

    Akhtar, S. S.; Arif, A. F. M.; Yilbas, B. S.

    2010-04-01

    Nitriding of complex-shaped extrusion dies may result in non-uniform nitride layers and hence a required hardness may not be achieved in some regions of the bearing area. The present study is carried out to assess the effect of extrusion die profile on the characteristics and growth behavior of nitride layers so that the critical die design feature can be identified to enhance the uniformity of the nitride layer. For this purpose, AISI H13 steel samples have been manufactured with profiles similar to those of hot extrusion dies. The samples were then gas nitrided under controlled nitriding potential. The uniformity and depth of nitride layers have been investigated in terms of compound layer and total nitride case depth for selected die features. The results of this study indicated the need to include the effect of profile on the nitride layer for the optimal die design with improved service life.

  18. Investigation on Effects of Die Orifice Layout on Three-Hole Porthole Extrusion of Aluminum Alloy 6063 Tubes

    NASA Astrophysics Data System (ADS)

    Zhang, Cunsheng; Zhao, Guoqun; Chen, Hao; Guan, Yanjin; Cai, Haijin; Gao, Baojie

    2013-05-01

    Currently, with the increasing demand of high production output, much attention is paid to the research and development of multi-hole extrusion die. However, owing to the complexity of multi-hole porthole extrusion technology, it has not been applied widely in practice for the production of aluminum profiles, especially for porthole die with an odd number of die orifices. The purpose of this study is to design a three-hole porthole die for producing an aluminum tube and to optimize the location of die orifices based on computer-aided design and engineering. First, three-hole extrusion dies for different locations of die orifices are designed. Then, extrusion processes with different multi-hole porthole dies are simulated by means of HyperXtrude. Through numerical simulation, metal flow, temperature distribution, welding pressure, extrusion load, and die stress, etc. could be obtained, and the effects of the location of die orifices on extrusion process are investigated. With the increasing distance between die orifice and extrusion center (described as eccentricity ratio), metal flow becomes nonhomogeneous, and twisting or bending deformation of profile occurs, but the welding pressure rises, which improves the welding quality of profiles. However, the required extrusion force, billet and die temperature, die displacement, and stress induce no significant changes. In comparison with the extrusion force during single-hole porthole extrusion, there is 18.5% decrease of extrusion force during three-hole porthole extrusion. Finally, design rules for this kind of multi-hole extrusion dies are summarized.

  19. Effect of Process Variables on the Formation of Streak Defects on Anodized Aluminum Extrusions: An Overview

    NASA Astrophysics Data System (ADS)

    Zhu, Hanliang; Couper, Malcolm J.; Dahle, Arne K.

    2012-04-01

    Streak defects are often present on anodized extrusions of 6xxx series aluminum alloys, increasing the fabrication cost of these products. Moreover, streaking often only becomes visible after etching and anodizing treatments, rather than in the as-extruded condition, making it difficult to identify the original causes and influencing factors of these defects. In this paper, various process variables that influence the formation of streak defects on anodized aluminium extrusions are reviewed on the basis of a literature review, industrial practice and experimental results. The influencing factors involved in various processing steps such as billet quality, extrusion process, die design and etching process are considered. Effective measures for preventing the formation of streak defects in industrial extrusion products are discussed.

  20. 75 FR 22109 - Aluminum Extrusions from the People's Republic of China: Initiation of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-27

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE International Trade Administration Aluminum Extrusions from the People's Republic of China: Initiation of Antidumping Duty Investigation EFFECTIVE DATE: April 27, 2010. FOR FURTHER INFORMATION CONTACT: John Hollwitz, Andrea Staebler Berton or...

  1. 75 FR 22114 - Aluminum Extrusions from the People's Republic of China: Initiation of Countervailing Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-27

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE International Trade Administration (C-570-968) Aluminum Extrusions from the People's Republic of China: Initiation of Countervailing Duty Investigation AGENCY: Import Administration, International Trade Administration, Department of Commerce....

  2. 76 FR 30650 - Aluminum Extrusions from the People's Republic of China: Antidumping Duty Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-26

    ...Based on affirmative final determinations by the Department of Commerce (the ``Department'') and the International Trade Commission (``ITC''), the Department is issuing an antidumping duty order on aluminum extrusions from the People's Republic of China (``PRC''). On May 13, 2010, the ITC notified the Department of its affirmative determination of material injury by reason of imports of......

  3. 77 FR 39683 - Aluminum Extrusions From the People's Republic of China: Preliminary Results of Changed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-05

    ... People's Republic of China: Final Determination of Sales at Less Than Fair Value, 76 FR 18524 (April 4... Final Determination of Sales at Less Than Fair Value, 76 FR 20627 (April 13, 2011). \\2\\ Id. \\3\\ See Aluminum Extrusions from the People's Republic of China: Antidumping Duty Order, 76 FR 30650 (May 26,...

  4. 78 FR 66895 - Aluminum Extrusions From the People's Republic of China: Preliminary Results of Changed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-07

    ...On June 20, 2013, the Department of Commerce (Department) received a request for changed circumstances reviews and a request to revoke, in part, the antidumping (AD) and countervailing duty (CVD) orders on aluminum extrusions from the People's Republic of China (PRC),\\1\\ with respect to certain rectangular wire. We published the notice of initiation of changed circumstances reviews on August......

  5. 75 FR 73041 - Aluminum Extrusions From the People's Republic of China: Postponement of Final Determination of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-29

    ... People's Republic of China: Initiation of Antidumping Duty Investigation, 75 FR 22109 (``Initiation... Determination of Sales at Less Than Fair Value, and Preliminary Determination of Targeted Dumping, 75 FR 69403... International Trade Administration Aluminum Extrusions From the People's Republic of China: Postponement...

  6. 78 FR 34986 - Aluminum Extrusions From the People's Republic of China: Preliminary Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-11

    ...The Department of Commerce (``the Department'') is conducting an administrative review of the antidumping duty order on aluminum extrusions from the People's Republic of China (``PRC'').\\1\\ The period of review (``POR'') is November 12, 2010, through April 30, 2012. The review covers two exporters of subject merchandise who are mandatory respondents: Kromet International, Inc. (``Kromet'');......

  7. 76 FR 18521 - Aluminum Extrusions From the People's Republic of China: Final Affirmative Countervailing Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-04

    ... Countervailing Duty Determination, 75 FR 54302 (September 7, 2010) (Preliminary Determination). From September 17... subsidized by the GOC. See Certain Aluminum Extrusions from China, 75 FR 34482 (June 17, 2010). Analysis of...; Countervailing Duties, 62 FR 27296, 27310 (May 19, 1997). Therefore, we have resorted to ``any reasonable...

  8. 75 FR 54302 - Aluminum Extrusions From the People's Republic of China: Preliminary Affirmative Countervailing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-07

    ...The Department of Commerce (the Department) preliminarily determines that countervailable subsidies are being provided to producers and exporters of aluminum extrusions from the People's Republic of China (the PRC). For information on the estimated subsidy rates, see the ``Suspension of Liquidation'' section of this...

  9. 78 FR 67116 - Aluminum Extrusions From the People's Republic of China: Notice of Partial Rescission of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-08

    ... Investigation; Opportunity To Request Administrative Review, 78 FR 25420, 25424 (May 1, 2013). \\2\\ See..., 78 FR 38924 (June 28, 2013) (Initiation Notice). \\3\\ See Department Memorandum regarding ``Deadline... Review, 74 FR 21781 (May 11, 2009); and Aluminum Extrusions From the People's Republic of China:...

  10. A Comparison Between ECAP and Conventional Extrusion for Consolidation of Aluminum Metal Matrix Composite

    NASA Astrophysics Data System (ADS)

    Haghighi, R. Derakhshandeh; Jahromi, S. A. Jenabali; Moresedgh, A.; Khorshid, M. Tabandeh

    2012-09-01

    In this study, two powder consolidation techniques, equal channel angular pressing (ECAP) and extrusion, were utilized to consolidate attritioned aluminum powder and Al-5 vol.% nano-Al2O3 composite powder. The effect of ECAP and extrusion on consolidation behavior of composite powder and mechanical properties of subsequent compacts are presented. It is found that three passes of ECAP in tube at 200 °C is capable of consolidating the composite to 99.29% of its theoretical density whereas after hot extrusion of the composite the density reached to 98.5% of its theoretical density. Moreover, extrusion needs higher temperature and pressing load in comparison to the ECAP method. Hardness measurements show 1.7 and 1.2 times higher microhardness for the consolidated composite and pure aluminum after ECAP comparing with the extruded ones, respectively. Microstructural investigations and compression tests demonstrate stronger bonds between the particles after three passes of ECAP than the extrusion. Furthermore, the samples after three passes of ECAP show better wear resistance than the extruded ones.

  11. Suitability of the Yield Criterion in Numerical Simulation of Stretch Bending of Aluminum Extrusions

    SciTech Connect

    Li, X.Q.; Zhou, X.B.; Wu, X.D.; Gao, H.Z.

    2005-08-05

    Stretch bending is commonly used to shape thin-walled extrusions in aerospace and automotive industries. The extrusions are pre-stretched and bent over rigid curved dies. Effective application of this process demands sufficient knowledge of how different parameters influence the final shape of the product. Numerical simulation is an effective approach to investigate these issues presently. However, the validity of simulation result depends strongly on a precise description of the mechanical behavior of the material. Due to crystallographic texture caused by the extrusion process, aluminium extrusions exhibit significant plastic anisotropy which need be described by advanced constitutive model. In this work stretch bending of aluminum extrusions is simulated by using different anisotropic criteria (Hill quadratic, Barlat three-parameter). The influence of two yield criteria on predicting maximum die force immediately before unloading, permanent sagging and vertical springback displacement in the middle section of extrusion are compared. Maximum die force and springback calculated by two yield criteria are found to be almost same. Permanent sagging is obviously underestimated by two yield criteria, however, prediction by Barlat three-parameter is closer to experiment than one of Hill quadratic yield criterion.

  12. Energy absorption in aluminum extrusions for a spaceframe chassis

    SciTech Connect

    Logan, R.W.; Perfect, S.A.; Parkinson, R.D.

    1994-09-19

    This work describes the design, finite-element analysis, and verifications performed by LLNL and Kaiser Aluminum for the prototype design of the CALSTART Running Chassis purpose-built electric vehicle. Component level studies, along with our previous experimental and finite-element works, provided the confidence to study the crashworthiness of a complete aluminum spaceframe. Effects of rail geometry, size, and thickness were studied in order to achieve a controlled crush of the front end structure. These included the performance of the spaceframe itself, and the additive effects of the powertrain cradle and powertrain (motor/controller in this case) as well as suspension. Various design iterations for frontal impact at moderate and high speed are explored.

  13. Finite Element Analysis and Die Design of Non-specific Engineering Structure of Aluminum Alloy during Extrusion

    SciTech Connect

    Chen, D.-C.; Lu, Y.-Y.

    2010-06-15

    Aluminum extension applies to industrial structure, light load, framework rolls and conveyer system platform. Many factors must be controlled in processing the non-specific engineering structure (hollow shape) of the aluminum alloy during extrusion, to obtain the required plastic strain and desired tolerance values. The major factors include the forming angle of the die and temperature of billet and various materials. This paper employs rigid-plastic finite element (FE) DEFORM 3D software to investigate the plastic deformation behavior of an aluminum alloy (A6061, A5052, A3003) workpiece during extrusion for the engineering structure of the aluminum alloy. This work analyzes effective strain, effective stress, damage and die radius load distribution of the billet under various conditions. The analytical results confirm the suitability of the current finite element software for the non-specific engineering structure of aluminum alloy extrusion.

  14. Co-extrusion of Discontinuously, Non-centric Steel-reinforced Aluminum

    SciTech Connect

    Foydl, A.; Haase, M.; Khalifa, N. Ben; Tekkaya, A. E.

    2011-05-04

    The process of manufacturing discontinuously non-centric steel reinforced aluminum by means of co-extrusion has been examined. By this process semi-finished reinforced profiles can be fabricated for further treatment through forging techniques. Therefore, steel reinforcement elements consisting of E295GC were inserted into conventional aluminum billets and co-extruded into two different solid profiles; a rectangle one by an extrusion ratio of 10.1:1 and a round one by 4.8:1. The used aluminum alloy is EN AW-6060. The billet temperature as well as the ram speed were varied to investigate their influence on the position of the reinforcement elements inside the strand. The measurement was done by a video measurement system, called Optomess A250, after milling off the strand. The distances between the elements in longitudinal direction were nearly constant, apart from the rear part of the strand. The same was observed for the distance of the steel elements to the profile edge. This due to the inhomogeneous material flow in the transverse weld, related to the billet-to-billet extrusion. The rotation of the reinforcement elements occurs because the elements flow nearby the shear zone. Further, micrographs were made to investigate the embedding situation and the grain size distribution. The embedding of the reinforcement elements were good in the solid round profile, but in the rectangle profile were found some kind of air pocket. The grain size of the aluminum alloy close to the steel elements is much smaller than in the other parts of the solid round profile.

  15. An investigation on diffusion bonding of aluminum to copper using equal channel angular extrusion process.

    PubMed

    Eslami, P; Taheri, A Karimi

    2011-06-30

    A new method for production of bimetallic rods, utilizing the equal channel angular extrusion (ECAE) process has been introduced before by previous researchers, but no attempt has been made to assess the effect of different temperatures and holding times in order to achieve a diffusional bond between the mating surfaces. In present research copper sheathed aluminum rods have been ECAEed at room temperature and subsequently held at a constant ECAE pressure, at different temperatures and holding times to produce a diffusional bond between the copper sheath and the aluminum core. The bonding quality of the joints was examined by shear strength test and a sound bonding interface was achieved. Based on the results, a bonding temperature of 200 °C and holding time of 60-80 min yielded the highest shear strength value. PMID:21760654

  16. An optimizing process of profiled cross-sectional aluminum alloy porthole die extrusion using response surface methodology

    NASA Astrophysics Data System (ADS)

    Zhou, Fujian; Li, Feng; Shi, Liansheng; Jiang, Hongwei

    2016-03-01

    The porthole die extrusion process of profiled cross-section hollow aluminum alloy is influenced by numerous factors, which brings inconvenience to the process design. In this paper, 7075 aluminum alloy is taken as an example, the fitting model of the ultimate load is analyzed by variance and regression analysis using response surface method (RSM). The influences of extrusion speed, friction factor and initial temperature on the change of extruded ultimate load are investigated systematically, and the important influence factors (initial temperature > friction factor > extrusion speed) to the load are determined eventually. By comparison, the error between the ultimate load model obtained after fitting and the calculated value is only 2.4%, further verifying the reliability of this model. The optimal objective is to minimize the ultimate load, then the optimum technological parameters are obtained by optimizing the process, where the initial temperature, the extrusion speed and the friction factor are 430∘C, 2.28mm/s and 0.31, respectively. The results provide a theoretical basis for the scientific design of the porthole die extrusion process of profiled cross-section hollow aluminum alloy.

  17. 76 FR 18524 - Aluminum Extrusions From the People's Republic of China: Final Determination of Sales at Less...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-04

    ...On November 12, 2010, the Department of Commerce (``Department'') published its preliminary determination of sales at less than fair value (``LTFV'') in the antidumping investigation of aluminum extrusions from the People's Republic of China (``PRC'').\\1\\ We invited interested parties to comment on our preliminary determination. Based on our analysis of the comments we received, we have made......

  18. 76 FR 20627 - Aluminum Extrusions From the People's Republic of China: Notice of Correction to the Final...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-13

    ...: Final Determination of Sales at Less Than Fair Value, 76 FR 18524 (April 4, 2011) (``AD Final... Affirmative Countervailing Duty Determination, 76 FR 18521, (April 4, 2011). Therefore, the Department will... International Trade Administration Aluminum Extrusions From the People's Republic of China: Notice of...

  19. 78 FR 42491 - Aluminum Extrusions from the People's Republic of China: Notice of Court Decision Not in Harmony...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-16

    ..., 76 FR 30650 (May 26, 2011) and Aluminum Extrusions from the People's Republic of China: Countervailing Duty Order, 76 FR 30653 (May 26, 2011) (``Orders''). \\2\\ See Final Results of Redetermination... automotive heating/cooling systems'') imported by Valeo, Inc., Valeo Engine Cooling Inc., and Valeo...

  20. Fatigue behavior of 6063 aluminum alloy extrusions for wind-turbine applications

    SciTech Connect

    Warren, A.S.

    1990-01-01

    The fatigue behavior of a 6063 aluminum alloy used in the Vertical Axis Wind Turbine (VAWT) blade extrusions was investigated under a variety of cyclic loading conditions and with different specimen geometries in order to examine the mechanisms of fatigue crack initiation and crack growth, and to provide fatigue data for use in life prediction models. The effect of open holes on fatigue crack initiation and crack growth, and on the S-N curves were investigated with plate bending. Fatigue life in plane bending was controlled by crack propagation. Hole preparation by drilling, or drilling and reaming were found to produce equivalent crack initiation behavior, and overall fatigue lives. Fatigue crack growth rates, including near-threshold behavior, were measured under LEFM conditions with compact tension specimens as a function of: heat treatment, crack plane orientation with respect to the extrusion direction, and R ratio. Low-cycle fatigue behavior and cyclic material properties were examined, and compared on the basis of material condition for extruded VAWT blade material, re-heat treated blade material and commercial 6063-T5 extruded rod. Low cyclic ductility values were observed in the extruded blade material.

  1. Production of Wire From AA7277 Aluminum Chips via Friction-Stir Extrusion (FSE)

    NASA Astrophysics Data System (ADS)

    Behnagh, Reza Abdi; Mahdavinejad, Ramezanali; Yavari, Amin; Abdollahi, Masoud; Narvan, Morteza

    2014-08-01

    In this research, fully consolidated wires from aluminum alloy AA7277 machining chips were produced by the friction-stir extrusion (FSE) process. The components used in the friction-stir extrusion process consist of a stationary cartridge and a rotating plunger with a scroll-faced head. The rotating plunger was rotated at three different speeds. Optical microscopy was used to probe the microstructures formed in the wires. The hardness profile of each sample is characterized using a Vickers microhardness tester. In this work, surface quality is sufficient by using a rotation speed of 160 rpm. Cold crack and hot crack defects were shown on wires fabricated using either too low or too high plunger rotation speeds. The microstructure of extruded wire is composed of fully equiaxed, recrystallized fine grains in the center of samples. The microhardness tests show an uneven distribution, and the hardness of the center was lower than that of the parent metal. The tensile tests revealed that the mechanical properties of the extruded wires were comparable with parent material.

  2. Extrusion of spark plasma sintered aluminum-carbon nanotube composites at various sintering temperatures.

    PubMed

    Kwon, Hansang; Kawasaki, Akira

    2009-11-01

    The combined processes of spark plasma sintering and hot extrusion were used to fabricate a multi-walled carbon nanotube (MWCNT) reinforced aluminum (Al) matrix composite. The structural defects of carbon nanotubes (CNT) at various sintering temperatures were investigated by Raman spectroscopy. A small amount of Al liquid phase was generated and it reacted with disordered CNTs, even during the solid-state spark plasma sintering process. The influence of Al carbides generated by the reaction between Al and disordered CNTs is discussed from a microstructural viewpoint and in relation to tensile strength. We conclude that structurally controlled CNTs could potentially be attractive for metal matrix applications, and could significantly improve the mechanical properties of AI-CNT composites. PMID:19908562

  3. Spall Properties of Aluminum 5083 Plate Fabricated using Equi-Channel Angular Extrusion and Rolling

    NASA Astrophysics Data System (ADS)

    Whelchel, Ricky; Thadhani, Naresh; Sanders, Thomas; Mathaudhu, Suveen; Kecskes, Laszlo

    2013-06-01

    The spall strength and Hugoniot Elastic Limit (HEL) of aluminum alloy 5083 (Al 5083) are compared for plates fabricated using equi-channel angular extrusion (ECAE) versus rolling. Al 5083 is a light-weight and strain-hardenable aluminum alloy used for armor plating in military transport vehicles, thus requiring the highest achievable spall strength. The spall strength of strain-hardenable alloys is a function of the grain structure and volume fraction of secondary phases, such as brittle inclusions, in addition to the extent of hardening. Materials processed by ECAE have a highly refined grain structure with little texturing and a large degree of plastic deformation, whereas rolled plates have a textured grain structure that aligns along the rolling direction. The spall behavior of Al 5083 for both forms was measured using plate impact gas gun experiments combined with rear free surface velocity measurements employing VISAR. The spall strength varied with impact orientation for the rolled plate but remained uniform for the ECAE material. Despite large differences in the HEL, the spall behavior for Al 5083 made by both processing techniques was controlled by the extent of brittle particles that acted as nucleation sites for damage during tensile failure.

  4. Characterization of aluminum processed by equal channel angular extrusion: Effect of processing route

    SciTech Connect

    Rebhi, Atef; Makhlouf, Thabet; Njah, Nabil; Champion, Yannick; Couzinie, Jean-Philippe

    2009-12-15

    Equal channel angular extrusion (ECAE) of aluminum alloys leads to enhanced strength. However, the effects of processing route on the resulting properties were not extensively investigated, and sometimes neglected. In the present work, an aluminum was processed by ECAE via routes B{sub C} and C using a die formed by two channels connected at an angle {phi} = 90 deg. Coherency lengths D calculated from X-ray diffraction peaks were 85 nm after the first passage. For route B{sub C}, it was kept constant when the number of passages N was increased. For route C, an increase of D was observed when increasing N. The remaining densities of dislocations {rho} were calculated using a recently published formula. A decrease of {rho} was observed during ECAE in route C but not in route B{sub C}. Mechanical tests allowed us to relate the increase of D and the decrease of {rho} to an enhanced recovery during ECAE via route C.

  5. Recent Innovations and Improvements in Infrared Thermometry within the Aluminum Extrusion Industry

    NASA Astrophysics Data System (ADS)

    Wright, Paul; Metcalfe, Stuart F.

    2003-09-01

    The three main locations for non-contact, infrared thermometers (IRTs) within the aluminum extrusion process are: on the incoming heated billets, at the die exit and following a quench. Each of these locations poses its own set of problems and requirements which have, until recently, limited the deployment and usefulness of IRTs within this industry. The previous generation of instruments required frequent recalibrations against thermocouple spot readings to maintain any sort of accuracy. Recent advances in measurement techniques however have made high accuracy routine and reduced operator input to a minimum. The deployment of these new instruments has been rapid. They have the potential to allow for improved product quality, press utilization and, therefore, material throughput. At the die and quench exits, the huge range of alloys and sections that are commonly encountered required the development of complex processing algorithms to represent the emissive behavior of the target. Once correctly established however, these facilitate instruments that offer "from the box" usability and enable automatic compensation for the vast majority of extruded sections. This allows constant die exit temperature to be maintained as well as control of the quench rate, which is critical on certain alloys. Billets, however, are very different to fresh sections in their surface characteristics, being fairly rough, oxidized and of constant (cylindrical) form. Here the requirement is for a complete longitudinal thermal profile, or "taper" along the billet. Correct taper permits "isothermal extrusion" — i.e. allows the die exit temperature and press speed to remain constant throughout the process. The importance of this for both uniformity of mechanical properties and improvements in press efficiency is now widely appreciated. An instrument has been developed, specifically for this measurement, using the principle of emissivity enhancement by multiple reflections. It has a fast speed

  6. Effect of hot and cold severe deformation by extrusion on the properties of lead and aluminum alloys

    NASA Astrophysics Data System (ADS)

    Ganiev, M. M.; Shibakov, V. G.; Pankratov, D. L.; Shibakov, R. V.

    2015-07-01

    The study of the effect of severe plastic deformation (SPD) by extrusion shows that the ductility of lead after several cycles of SPD increases significantly (3-4 times) as compared to as-cast samples. An aluminum alloy after this processing is hardened by a factor of 2.3-2.5, with ductility decreasing by 2.5-2.7 times, as compared to the as-delivered state.

  7. Validation of a systematic approach to modeling spray quenching of aluminum alloy extrusions, composites, and continuous castings

    SciTech Connect

    Hall, D.D.; Mudawar, I.; Morgan, R.E.; Ehlers, S.L.

    1997-02-01

    Optimal cooling of aluminum alloys following the high-temperature extrusion process suppresses precipitation of intermetallic compounds and results in a part capable of possessing maximum strength and hardness after the subsequent age-hardening process. Rapid quenching suppresses precipitation but can lad to large spatial temperature gradients in complex-shaped parts, causing distortion, cracking, high residual stress, and/or nonuniform mechanical properties. Conversely, slow cooling significantly reduces or eliminates these undesirable conditions but allows considerable precipitation, resulting in low strength, soft spots, and/or low corrosion resistance. This study presents a systematic method of locating and operating multiple spray nozzles for any shaped extrusion such that uniform, rapid cooling and superior mechanical and metallurgical properties are achieved. New correlations, offering increased accuracy and less computational time, were formulated for the high-temperature boiling regimes which have a critical influence on final mechanical properties. The quench factor technique related predicted thermal history to metallurgical transformations occurring within the extrusion to predict hardness distribution. The validity of this unique approach was demonstrated by comparing model predictions to the temperature response (and hardness after artificial aging) of an L-shaped Al2024-T6 extrusion to quenches with multiple, overlapping water sprays. The validation study reported herein concludes by exploring the possibility of applying quenching technology to improving the properties of extruded metal-matrix composites such as SiC{sub p}/Al6061 and cast alloys.

  8. Validation of a systematic approach to modeling spray quenching of aluminum alloy extrusions, composites, and continuous castings

    SciTech Connect

    Hall, D.; Mudawar, I.; Morgan, R.E.; Ehlers, S.L.

    1996-12-31

    Optimal cooling of aluminum alloys following the high temperature extrusion process suppresses precipitation of intermetallic compounds and results in a part capable of possessing maximum strength and hardness after the subsequent age-hardening process. Rapid quenching suppresses precipitation but can lead to large spatial temperature gradients in complex-shaped parts causing distortion, cracking, high residual stress, and/or nonuniform mechanical properties. Conversely, slow cooling significantly reduces or eliminates these undesirable conditions but allows considerable precipitation resulting in low strength, soft spots, and/or low corrosion resistance. This study presents a systematic method of locating and operating multiple spray nozzles for any shaped extrusion such that uniform, rapid cooling and superior mechanical and metallurgical properties are achieved. A spray nozzle database was compiled by measuring the distribution of spray hydrodynamic parameters (volumetric spray flux, mean drop diameter, and mean drop velocity) throughout the spray field of various industrial nozzles. Spray heat transfer correlations, which link the local spray hydrodynamic parameters to the heat transfer rate in each of the boiling regimes experienced by the surface, defined the spatially nonuniform boundary conditions in a numerical model of the quenching process which also accounted for interference between adjacent spray fields. The quench factor technique relates, predicted thermal history to metallurgical transformations occurring within the extrusion to predict hardness distribution. The validity of this unique approach was demonstrated by comparing model predictions to the temperature response (and hardness after artificial aging) of an L-shaped Al 2024-T6 extrusion to quenches with multiple, overlapping water sprays.

  9. 76 FR 80887 - Antidumping Order on Aluminum Extrusions from the People's Republic of China: Initiation of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-27

    ... Extrusions From the People's Republic of China: Final Determination of Sales at Less Than Fair Value, 76 FR... Correction to the Final Determination of Sales at Less Than Fair Value, 76 FR 20627 (April 13, ] 2011). As a... People's Republic of China: Antidumping Duty Order, 76 FR 30650 (May 26, 2011). On November 7, 2011,...

  10. Microstructure investigations of streak formation in 6063 aluminum extrusions by optical metallographic techniques.

    PubMed

    Vander Voort, George; Suárez-Peña, Beatriz; Asensio-Lozano, Juan

    2013-04-01

    The present study investigates the effect of the solidification strategy for AA 6063 alloy on the surface appearance of anodized extrusions. The microstructure of the samples was analyzed using both light optical microscopy and scanning electron microscopy. Results show that if heavy segregation occurs from rapid solidification, coarse Mg2Si particles form, thus reducing the potential for precipitation strengthening by the finer β-Mg2Si developed in the solid state. Differentially-strained regions formed during hot extrusion induce differences in particle size for magnesium silicide (Mg2Si) precipitates. Anodizing generates surface roughness due to Mg2Si particle dissolution and AlFeSi decohesion, which is related to both particle size and deformation. During anodizing, an oxide layer forms on the surface of the extruded products, which can lead to streak formation, usually a subject of rejection due to unacceptable heterogeneous reflectivity. PMID:23481588

  11. Characterization of ultra-fine grained aluminum produced by accumulative back extrusion (ABE)

    SciTech Connect

    Alihosseini, H.; Faraji, G.; Dizaji, A.F.; Dehghani, K.

    2012-06-15

    In the present work, the microstructural evolutions and microhardness of AA1050 subjected to one, two and three passes of accumulative back extrusion (ABE) were investigated. The microstructural evolutions were characterized using transmission electron microscopy. The results revealed that applying three passes of accumulative back extrusion led to significant grain refinement. The initial grain size of 47 {mu}m was refined to the grains of 500 nm after three passes of ABE. Increasing the number of passes resulted in more decrease in grain size, better microstructure homogeneity and increase in the microhardness. The cross-section of ABEed specimen consisted of two different zones: (i) shear deformation zone, and (ii) normal deformation zone. The microhardness measurements indicated that the hardness increased from the initial value of 31 Hv to 67 Hv, verifying the significant microstructural refinement via accumulative back extrusion. - Highlights: Black-Right-Pointing-Pointer A significant grain refinement can be achieved in AA1050, Al alloy by applying ABE. Black-Right-Pointing-Pointer Microstructural homogeneity of ABEed samples increased by increasing the number of ABE cycles. Black-Right-Pointing-Pointer A substantial increase in the hardness, from 31 Hv to 67 Hv, was recorded.

  12. Microstructure and mechanical properties of 7075 aluminum alloy nanostructured composites processed by mechanical milling and indirect hot extrusion

    SciTech Connect

    Flores-Campos, R.; Estrada-Guel, I.; Miki-Yoshida, M.; Martinez-Sanchez, R.; Herrera-Ramirez, J.M.

    2012-01-15

    Nanostructured composites of 7075 aluminum alloy and carbon coated silver nanoparticles were produced by mechanical milling and indirect hot extrusion. The milling products were obtained in a high energy SPEX ball mill, and then were compacted by uniaxial load and pressure-less sintered under argon atmosphere. Finally, the sintered product was hot extruded. Carbon coated silver nanoparticles were well distributed in the matrix of the extruded material. Tensile tests were carried out to corroborate the hypothesis that second phase particles, well dispersed in the matrix, improve the strength of the material. High resolution transmission electron microscopy was employed to locate and make sure that the silver nanoparticles were homogeneously and finely dispersed. Highlights: Black-Right-Pointing-Pointer 7075 Al nanostructured composites can be produced by mechanical milling. Black-Right-Pointing-Pointer Carbon coated silver nanoparticles are well dispersed into aluminum matrix. Black-Right-Pointing-Pointer Ductile Ag-C NP's improve the mechanical properties of the 7075 Al-alloy. Black-Right-Pointing-Pointer Ag-C NP's content has an important effect in the particle and crystallite size. Black-Right-Pointing-Pointer Ag-C NP's keep their morphology after milling and conformation processes.

  13. Development of lightweight aluminum compression panels reinforced by boron-epoxy infiltrated extrusions

    NASA Technical Reports Server (NTRS)

    Roy, P. A.; Mcelman, J. A.; Henshaw, J.

    1973-01-01

    Analytical and experimental studies were performed to evaluate the structural efficiencies afforded by the selective reinforcement of conventional aluminum compression panels with unidirectional boron epoxy composite materials. A unique approach for selective reinforcement was utilized called boron/epoxy infiltration. This technique uses extruded metal sections with preformed hollow voids into which unidirectional boron filaments are drawn and subsequently infiltrated with resin to form an integral part. Simplified analytical models were developed to investigate the behavior of stiffener webs with reinforced flanges. Theoretical results are presented demonstrating the effects of transverse shear, of the reinforcement, flange eccentricity and torsional stiffness in such construction. A series of 55 tests were conducted on boron-infiltrated rods and extruded structural sections.

  14. Microhardness Distribution and Microstructural Evolution in Pure Aluminum Subjected to Severe Plastic Deformation: Elliptical Cross-Sectioned Spiral Equal-Channel Extrusion (ECSEE)

    NASA Astrophysics Data System (ADS)

    Li, Jinghui; Li, Fuguo; Ma, Xinkai; Chen, Han; Ma, Zhanchao; Li, Jiang

    2015-11-01

    Elliptical cross-sectioned spiral equal-channel extrusion (ECSEE), one of the severe plastic deformation techniques, is of great efficiency in producing bulk ultrafine or nanostructured materials. In this paper, the simulation and experimental researches on ECSEE of high-purity aluminum were conducted to investigate the equivalent strain distribution and microhardness distribution on three orthogonal planes, as well as microstructural evolution. Simulation result shows a significant strain gradient on three planes. Microhardness tests comprise the similar results to strain distribution. According to transmission electron microscopy (TEM) results, microstructural evolution ranged from coarse structures to ultrafine structures by undergoing the shear bands, subgrains, high-angle misorientation grain boundaries and equiaxed structures. There are also some distinctions with reference to grain refinement level, grain boundary styles and dislocation distribution on different positions. The TEM investigations are in good agreement with microhardness tests.

  15. A Processing Map for Hot Deformation of an Ultrafine-Grained Aluminum-Magnesium-Silicon Alloy Prepared by Mechanical Milling and Hot Extrusion

    NASA Astrophysics Data System (ADS)

    Asgharzadeh, Hamed; Rahbar Niazi, Masoud; Simchi, Abdolreza

    2015-12-01

    Uniaxial compression test at different temperatures [573 K to 723 K (300 °C to 450 °C)] and strain rates (0.01 to 1 s-1) was employed to study the hot deformation behavior of an ultrafine-grained (UFG) Al6063 alloy prepared by the powder metallurgy route. The UFG alloy with an average grain size of ~0.3 µm was prepared by mechanical milling of a gas-atomized aluminum alloy powder for 20 hours followed by hot powder extrusion at 723 K (450 °C). To elaborate the effect of grain size, the aluminum alloy powder was extruded without mechanical milling to attain a coarse-grained (CG) structure with an average grain size of about 2.2 µm. By employing the dynamic materials model, processing maps for the hot deformation of the UFG and CG Al alloy were constructed. For investigation of microstructural evolutions and deformation instability occurring upon hot working, optical microscopy, scanning electron microscopy coupled with electron backscattered diffraction and transmission electron microscopy were utilized. It is shown that the grain refinement increases the deformation flow stress while reducing the strain hardening and power dissipation efficiency during the deformation process at the elevated temperatures. Restoration mechanisms, including dynamic recovery and recrystallization are demonstrated to control microstructural evolutions and thus the deformation behavior. Coarsening of the grain structure in the UFG alloy is illustrated, particularly when the deformation is performed at high temperatures and low strain rates. The manifestations of instability are observed in the form of cracking and void formation.

  16. Tensile Properties of Nano AL2O3 Particulate-Reinforced Aluminum Matrix Composites by Mechanical Alloying and Hot Extrusion

    NASA Astrophysics Data System (ADS)

    Mehdinia, M.; Jenabali Jahromi, S. A.

    The powder of the micro Al and variant volume fractions of nano Al2O3 were milled by a high energy planetary ball-mill. By milling, a homogenous distribution of nano Al2O3 particles in the metal matrix were developed. Then the milled powder was cold compressed and sintered at 545°C for one hr. The mold and the sintered sample hold in a furnace until the temperature reached 545°C. Then the hot 27mm diameter sample was extruded to 6mm diameter. From the extruded specimens, tensile, hardness and microstructure of the prepared specimens were determined. By these tests the effect of milling time, the percent of nano-particles and the microstructure were evaluated. The hardness and tensile behaviors of aluminum matrix composites reinforced with nano Al2O3 particulate have been found to increase remarkably with the volume fraction of the reinforcement.

  17. Effect of extrusion ratio on paraffinic mineral oil lubricant in cold forward extrusion

    NASA Astrophysics Data System (ADS)

    Hafis, S. M.; Ridzuan, M. J. M.; Imaduddin Helmi, W. N.; Syahrullail, S.

    2012-06-01

    A finite element (FE) analysis is made for steady-state two-dimensional forward extrusion with three different extrusion ratio values. Predicting extrusion force of aluminum billet extruded with palm oil lubricant will definitely be helpful in deciding the right extrusion ratio. Hence, the finite element method was applied to investigate the influence of extrusion ratio on palm oil lubricant. The extrusion ratios evaluated were 1.5, 2, and 3. The reference of the study was in accordance to the experiment results of 0.1 mg paraffinic mineral oil grade 95 (Pr95) with kinematic viscosity of 90.12 mm2/s at 40 °C for the extrusion ratio of 3. The result was found to be reliable once the FE model was validated by the established work. The extrusion force for each extrusion ratio was described and evaluated. The FE analysis also accounts for plasticity material flow and equivalent plastic strains in the deformation region. The analysis agreed that the extrusion ratio of 1.5 reduced the extrusion force compared to the extrusion ratio of 2 and 3. This was confirmed by the plotted equivalent plastic strain deformation which shows that the high value of equivalent plastic strain near the extrusion die surface was decreased. As a result, the extrusion force becomes greater with the increasing of extrusion ratio.

  18. Characterization of the Microstructure, Fracture, and Mechanical Properties of Aluminum Alloys 7085-O and 7175-T7452 Hollow Cylinder Extrusions

    NASA Astrophysics Data System (ADS)

    Benoit, Samuel G.; Chalivendra, Vijaya B.; Rice, Matthew A.; Doleski, Robert F.

    2016-06-01

    Microstructural, tensile, and fracture characterizations of cylindrically forged forms of aluminum alloys AA7085-O and AA7175-T7452 were performed. Mechanical and fracture properties were investigated along radial, circumferential, and longitudinal directions to determine directional dependency. American Society for Testing and Materials (ASTM) test methods (ASTM E8-04 and ASTM E1820) were employed for both the tensile and fracture characterizations, respectively. The tensile and fracture properties were related to microstructure in each direction. The strength, elongation at break, and ultimate tensile strength of AA7085-O were higher than those of AA7175-T7452. AA7175-T7452 alloy failed in a brittle manner during fracture studies. AA7085-O outperformed AA7175-T7452 on fracture energy in all of the orientations studied. Smaller grain sizes on the planes normal to circumferential and longitudinal directions showed improvement in both elongation at break and fracture energy values compared to those of radial direction. Scanning electron microscopy images demonstrated cleavage fracture in AA7175-T7452 and transgranular fracture in AA7085-O.

  19. Characterization of the Microstructure, Fracture, and Mechanical Properties of Aluminum Alloys 7085-O and 7175-T7452 Hollow Cylinder Extrusions

    NASA Astrophysics Data System (ADS)

    Benoit, Samuel G.; Chalivendra, Vijaya B.; Rice, Matthew A.; Doleski, Robert F.

    2016-09-01

    Microstructural, tensile, and fracture characterizations of cylindrically forged forms of aluminum alloys AA7085-O and AA7175-T7452 were performed. Mechanical and fracture properties were investigated along radial, circumferential, and longitudinal directions to determine directional dependency. American Society for Testing and Materials (ASTM) test methods (ASTM E8-04 and ASTM E1820) were employed for both the tensile and fracture characterizations, respectively. The tensile and fracture properties were related to microstructure in each direction. The strength, elongation at break, and ultimate tensile strength of AA7085-O were higher than those of AA7175-T7452. AA7175-T7452 alloy failed in a brittle manner during fracture studies. AA7085-O outperformed AA7175-T7452 on fracture energy in all of the orientations studied. Smaller grain sizes on the planes normal to circumferential and longitudinal directions showed improvement in both elongation at break and fracture energy values compared to those of radial direction. Scanning electron microscopy images demonstrated cleavage fracture in AA7175-T7452 and transgranular fracture in AA7085-O.

  20. GRAPHITE EXTRUSIONS

    DOEpatents

    Benziger, T.M.

    1959-01-20

    A new lubricant for graphite extrusion is described. In the past, graphite extrusion mixtures have bcen composed of coke or carbon black, together with a carbonaceous binder such as coal tar pitch, and a lubricant such as petrolatum or a colloidal suspension of graphite in glycerin or oil. Sinee sueh a lubricant is not soluble in, or compatible with the biiider liquid, such mixtures were difficult to extrude, and thc formed pieees lacked strength. This patent teaches tbe use of fatty acids as graphite extrusion lubricants and definite improvemcnts are realized thereby since the fatty acids are soluble in the binder liquid.

  1. Food extrusion.

    PubMed

    Harper, J M

    1978-01-01

    Extrusion processing has become an important food process in the manufacture of pasta, ready-to-eat cereals, snacks, pet foods, and textured vegetable protein (TVP). An extruder consists of tightly fitting screw rotating within a stationary barrel. Preground and conditioned ingredients enter the screw where they are conveyed, mixed, and heated by a variety of processes. The product exits the extruder through a die where it usually puffs and changes texture from the release of steam and normal forces. Mathematical models for extruder flow and torque have been found useful in describing exclusion operations. Scale-up can be facilitated by the application of these models. A variety of food extruder designs have developed. The differences and similarity of design are discussed. Pertinent literature on the extrusion of cereal/snack products, full-fat soy, TVP, pet foods (dry and semi-moist), pasta, and beverage or other food bases are discussed. In many of these applications, the extruder is a high temperature, short time process which minimizes losses in vitamins and amino acids. Color, flavor, and product shape and texture are also affected by the extrusion process. Extrusion has been widely applied in the production of nutritious foods. Emphasis is placed on the use of extrusion to denature antinutritional factors and the improvement of protein quality and digestibility. PMID:378548

  2. The effect of strain path on the development of deformation structures in severely deformed aluminum alloys processed by ECAE[Equal Channel Angular Extrusion

    SciTech Connect

    Gholinia, A.; Prangnell, P.B.; Markushev, M.V.

    2000-03-14

    Equal channel angular extrusion (ECAE) has been used to investigate the formation of submicron grain structures in Al-alloys deformed to ultra-high plastic strains by different strain paths. The different strain paths were obtained by rotating billets through 0, 90, and 190{degree} between each extrusion cycle. High resolution EBSD analysis has been employed to measure the boundary misorientations within the deformation structures. This has highlighted great differences in the evolution of the deformed state, as a function of the strain path, even after effective strains as high as 16. It has been demonstrated that the most effective method of forming a submicron grain structure by severe plastic deformation is to maintain a constant strain path. Processing routes involving a 180{degree} rotation reverse the shear strain every second pass and this prevents the build up of significant number of new high angle boundaries. When a sample is processed with an alternative clockwise and anticlockwise 90{degree} rotation, between each extrusion cycle the billet is deformed on two shear planes, each of which experiences half the total strain, compared to the single shear plane when there is no rotation. This reduces the rate of formation of high angle boundaries. With a constant clockwise 90{degree} rotation the sample is also deformed on two alternate shear planes, but the total strain becomes redundant every fourth extrusion cycle. However, in this case each shear is reversed out of sequence after first deforming the billet on the alternate shear plane. This appears to be a much more effective means of forming new high angle boundaries than 180{degree} rotation, where the shear strain is immediately reversed each alternate cycle, but is still less efficient than deformation with a constant strain path.

  3. Development of Crystallographic Texture and Grain Refinement in the Aluminum Layer of CU-AL-CU Tri-Layer Composite Deformed by Equal Channel Angular Extrusion

    NASA Astrophysics Data System (ADS)

    Tolaminejad, B.; Taheri, A. Karimi; Shahmiri, M.; Arabi, H.

    The present research is concerned with the aluminum layer of a loosely packed tri-layer copper-aluminum-copper composite deformed by ECAE process. Electron back scattered diffraction (EBSD), transmission electron microscope, and X-ray technique were employed to investigate the detailed changes occurring in the microtexture, microstructure (cell size and misorientation), and dislocation density evolution during consecutive passes of ECAE process performed on the composite based on route Bc. According to tensile test results, the yield stress of the aluminum layer was increased significantly after application of ECAE throughout the four repeated passes and then slightly decreased. An ultrafine grain size within the range of 500-600 nm was obtained in the Al layer by increasing the thickness of copper layers. It was observed that the reduction of grain size in the aluminum layer is nearly 57% more than that of an ECAE-ed single layer aluminum billet. Also, the grain refinement of the aluminum layer is accelerated throughout 8 passes. This observation was attributed to the higher rate of dislocation interaction, cell formation and texture development during the ECAE of the composite compared to those of the single billet.

  4. The effects of late homogenization conditions on the Mg2Si particle size in a slow pre-heated 6063 aluminum extrusion billet

    NASA Astrophysics Data System (ADS)

    Kayıkcı, R.; Kocaman, E.; Şirin, S.; ćolak, M.

    2015-03-01

    In order to investigate the effect of late homogenization conditions on the Mg2Si precipitation of 6063 grade extrusion billets are slow pre-heated to intentionally have large Mg2Si particle precipitation. Then the billets are water quenched to preserve this microstructure for late homogenizations. Finally billets are re-heated using two different furnace temperature as 450°C and 500°C at which temperatures the billet are held for 0.5 h, 1 h, 1.5 h, 2 h and 2.5 h periods and water quenched before being taken to metallographic examinations.

  5. 40 CFR 467.30 - Applicability; description of the extrusion subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... extrusion subcategory. 467.30 Section 467.30 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ALUMINUM FORMING POINT SOURCE CATEGORY Extrusion Subcategory § 467.30 Applicability; description of the extrusion subcategory. This subpart applies to discharges...

  6. 40 CFR 467.30 - Applicability; description of the extrusion subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... extrusion subcategory. 467.30 Section 467.30 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ALUMINUM FORMING POINT SOURCE CATEGORY Extrusion Subcategory § 467.30 Applicability; description of the extrusion subcategory. This subpart applies to discharges...

  7. Aluminum space frame technology

    SciTech Connect

    Birch, S.

    1994-01-01

    This article examines the increased application of aluminum to the construction of automobile frames. The topics of the article include a joint venture between Audi and Alcoa, forms in which aluminum is used, new alloys and construction methods, meeting rigidity and safety levels, manufacturing techniques, the use of extrusions, die casting, joining techniques, and pollution control during manufacturing.

  8. Optimizing the seamless tube extrusion process using the finite element method

    NASA Astrophysics Data System (ADS)

    Li, Feng; Li, Li; Wang, Xiang; Ma, Xu Liang

    2010-03-01

    In order to reveal the mechanism of extrusion forming for large-scale aluminum alloy seamless pipe, in this research the rigid-viscous plastic finite element method was used to analyze the effect of the technological parameters of the aluminum alloy pipe extrusion process, consistent with the use requirements.

  9. Extrusion cooking: Legume pulses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extrusion is used commercially to produce high value breakfast and snack foods based on cereals such as wheat or corn. However, this processing method is not being commercially used for legume pulses seeds due to the perception that they do not expand well in extrusion. Extrusion cooking of pulses (...

  10. The visioplastic method for analysis of large extrusion strains

    SciTech Connect

    Peacock, H. ); Berghaus, D. . School of Civil Engineering)

    1990-01-01

    Large plastic strains are produced when a metal billet is pressed through an extrusion die. This paper describes a method for obtaining the distribution of these strains during axisymmetric extrusion. The method is experimental-numerical and is based on a study of laminar flow lines produced in the extruded material. Several results are obtained using this analysis. These include the effects of extrusion tooling temperature and extrusion ratio. The method is also modified to study extrusion of powder metal, where the variable density invalidates the usual assumption of incompressibility. The flowline-strain relationship was originally set forth by Thomsen, Yang and Kobayashi and is referred to as viscoplasticity. The method described in this paper proceeds from that developed by Medrano and Gillis for axisymmetric extrusion. There are several differences. The experimental procedure has been changed to permit extrusion analysis at the high aluminum forming temperature (up to 430{degrees}C), thus allowing temperature effects to be studied. Numerical improvements permit the analysis at high extrusion ratios. The flow function has been redefined to permit the study of variable density material. 6 refs., 8 figs., 1 tab.

  11. Extrusion die and method

    DOEpatents

    Lipp, G. Daniel

    1994-04-26

    A method and die apparatus for manufacturing a honeycomb body of rhombic cell cross-section by extrusion through an extrusion die of triangular cell discharge slot configuration, the die incorporating feedholes at selected slot intersections only, such that slot segments communicating directly with the feedholes discharge web material and slot segments not so connected do not discharge web material, whereby a rhombic cell cross-section in the extruded body is provided.

  12. Extrusion of compound refractive x-ray lenses.

    SciTech Connect

    Young, K.; Khounsary, A.; Experimental Facilities Division; IIT

    2004-01-01

    Compound refractive lenses (CRLs) are arrays of lenses designed to focus x-rays. The advantage of a focused x-ray beam is improvement in imaging resolution for applications such as microscopy and tomography. CRLs are desirable due to their simple designs and ease in implementation and alignment. One method of fabricating CRLs is extrusion. Extrusion can be employed to produce, for example, aluminum CRLs for high-energy applications because many aluminum products are produced in this manner. Multiple lenses can be extruded in an array in a single run. This method is relatively cost effective compared to others methods of fabricating CRLs. Two generations of extruded aluminum CRLs have been manufactured to date with lens wall thicknesses of 200 and 100 {micro}m, respectively. The first-generation CRL yielded focusing and established the potential to produce high gain if reduced wall thicknesses could be achieved. Testing of the second generation is reported here.

  13. Extrusion die and method

    DOEpatents

    Lipp, G. Daniel

    1994-05-03

    A method and die apparatus for manufacturing a honeycomb body of triangular cell cross-section and high cell density, the die having a combination of (i) feedholes feeding slot intersections and (ii) feedholes feeding slot segments not supplied from slot intersections, whereby a reduction in feedhole count is achieved while still retaining good extrusion efficiency and extrudate uniformity.

  14. Extrusion cast explosive

    DOEpatents

    Scribner, Kenneth J.

    1985-01-01

    Improved, multiphase, high performance, high energy, extrusion cast explosive compositions, comprising, a crystalline explosive material; an energetic liquid plasticizer; a urethane prepolymer, comprising a blend of polyvinyl formal, and polycaprolactone; a polyfunctional isocyanate; and a catalyst are disclosed. These new explosive compositions exhibit higher explosive content, a smooth detonation front, excellent stability over long periods of storage, and lower sensitivity to mechanical stimulants.

  15. Control of Extrusion

    NASA Astrophysics Data System (ADS)

    Zhuromskii, V. M.

    2016-03-01

    The principle and engineering of a system for automatic control of the tension of the thread and the productivity of the process of extrusion of polyacrylonitrile fibers have been presented. The control system is based on the use of functional features of a modern frequency controlled electric drive.

  16. Extrusion cast explosive

    DOEpatents

    Scribner, K.J.

    1985-11-26

    Disclosed is an improved, multiphase, high performance, high energy, extrusion cast explosive compositions, comprising, a crystalline explosive material; an energetic liquid plasticizer; a urethane prepolymer, comprising a blend of polyvinyl formal, and polycaprolactone; a polyfunctional isocyanate; and a catalyst. These new explosive compositions exhibit higher explosive content, a smooth detonation front, excellent stability over long periods of storage, and lower sensitivity to mechanical stimulants. 1 fig.

  17. Extrusion cast explosive

    DOEpatents

    Scribner, K.J.

    1985-01-29

    Improved, multiphase, high performance, high energy, extrusion cast explosive compositions, comprising, a crystalline explosive material; an energetic liquid plasticizer; a urethane prepolymer, comprising a blend of polyvinyl formal, and polycaprolactone; a polyfunctional isocyanate; and a catalyst are disclosed. These new explosive compositions exhibit higher explosive content, a smooth detonation front, excellent stability over long periods of storage, and lower sensitivity to mechanical stimulants. 1 fig.

  18. Near-net-shape titanium alloy extrusions

    SciTech Connect

    Boyer, R.R.; Barta, E.R.; Henderson, J.W.

    1989-03-01

    The Ti-10V-2Fe-3Al has been used in an experimental program involving the development of Ti-alloy extrusion processes capable of achieving surfaces that do not require 100-percent machining. Attention was given to the effects of extrusion temperature and heat treatment on the mechanical properties of the near-net-shape extrusions; in general, the properties of direct-aged materials are found to be sensitive to extrusion temperatures, with tensile strength increasing with extrusion temperature. The double open-hole fatigue strength of extrusion specimens was ascertained. Direct-aged specimens tested at 276 MPa are projected to fail at 100,000 cycles. 7 refs.

  19. Means of determining extrusion temperatures

    DOEpatents

    McDonald, Robert E.; Canonico, Domenic A.

    1977-01-01

    In an extrusion process comprising the steps of fabricating a metal billet, heating said billet for a predetermined time and at a selected temperature to increase its plasticity and then forcing said heated billet through a small orifice to produce a desired extruded object, the improvement comprising the steps of randomly inserting a plurality of small metallic thermal tabs at different cross sectional depths in said billet as a part of said fabricating step, and examining said extruded object at each thermal tab location for determining the crystal structure at each extruded thermal tab thus revealing the maximum temperature reached during extrusion in each respective tab location section of the extruded object, whereby the thermal profile of said extruded object during extrusion may be determined.

  20. Guide for extrusion dies eliminates straightening operation

    NASA Technical Reports Server (NTRS)

    Gyorgak, C. A.; Hoover, R. J.

    1964-01-01

    To prevent distortion of extruded metal, a guidance assembly is aligned with the die. As the metal emerges from the extrusion dies, it passes directly into the receiver and straightening tube system, and the completed extrusion is withdrawn.

  1. Characterization of Al-Cu-Li Alloy 2090 Near Net Shape Extrusion

    NASA Technical Reports Server (NTRS)

    Birt, M. J.; Domack, M. S.; Hafley, R. A.; Pollock, W. D.

    1998-01-01

    Aluminum-lithium (Al-Li) alloys near net shape extrusions are being evaluated for potential application in launch vehicle structures. The objective of this study was to determine tensile and fracture properties, corrosion resistance, and weldability of integrally stiffened panels of Al-Cu-Li alloy 2090 in the T8 temper. The microstructure was pre-dominantly unrecrystallized. Texture analyses revealed the presence of fiber components in the stiffeners and a combination of fiber and rolling components in the skin. Variations in grain morphology and texture through the extruded cross section were correlated with the tensile, fracture, and corrosion behavior. Tensile strengths at room and cryogenic temperatures of the 2090 extrusions were similar to other 2090 product forms and were higher than 2219-T87, the primary structural material in the Space Shuttle external tank; however, ductilities were lower. The fracture resistance of the 2090 extrusion was lower than 2219-T87 plate at room temperature. At cryogenic temperatures, tensile ductility and fracture behavior of the 2090 extrusion were similar to other 2090 product forms but were lower than 2219-T87 plate. The exfoliation and stress corrosion resistance of the 2090 extrusion compared favorably with the characteristics of other 2090 product forms. The weldability and weldment properties of the extrusions were similar to 2090 and 2219 plates.

  2. Power Factor Study Reduces Energy Costs at Aluminum Extrusion Plant (Alcoa North American Extrusions)

    SciTech Connect

    2001-08-01

    This case study is the latest in a series on industrial firms who are implementing energy efficient technologies and system improvements into their manufacturing processes. The case studies document the activities, savings, and lessons learned on these projects.

  3. WASTE MINIMIZATION ASSESSMENT FOR AN ALUMINUM EXTRUSIONS MANUFACTURERS

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) has funded a pilot project to assist small- and medium-size manufacturers who want to minimize their generation of waste but who lack the expertise to do so. aste Minimization Assessment Centers (WMACs) were established at selected u...

  4. WASTE MINIMIZATION ASSESSMENT FOR A MANUFACTURER OF ALUMINUM EXTRUSIONS

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) has funded a pilot project to assist small- and medium-size manufacturers who want to minimize their generation of hazardous waste but who lack the expertise to do so. aste Minimization Assessment Centers (WMACs) are established at s...

  5. High temperature, high strain rate extrusion of ultrahigh-carbon steels

    SciTech Connect

    Lesuer, D R; Syn, C K; Sherby, O D

    2000-08-23

    It is shown that high rate extrusion is a viable production process for obtaining desirable microstructures and mechanical properties in ultrahigh carbon steels (UHCSs). The coefficient of friction for extrusion was determined for the UHCSs as well as five other materials and shown to be a function of stress--decreasing with increasing stress. The extruded UHCSs deform by a diffusion-controlled dislocation creep process. Stacking fault energies have been calculated from the extrusion data and observed to decrease with increasing concentrations of silicon, aluminum and chromium. Microstructures are either ultrafine pearlite when extruded above the eutectoid temperature or ultrafine spheroidite when extruded below the eutectoid temperature. The resulting strength--ductility properties are shown to be superior to those obtained in high-strength low alloy steels.

  6. Aluminum Hydroxide

    MedlinePlus

    Aluminum hydroxide is used for the relief of heartburn, sour stomach, and peptic ulcer pain and to ... Aluminum hydroxide comes as a capsule, a tablet, and an oral liquid and suspension. The dose and ...

  7. Solid State Bonding Mechanics In Extrusion And FSW: Experimental Tests And Numerical Analyses

    SciTech Connect

    Buffa, G.; Fratini, L.; Donati, L.; Tomesani, L.

    2007-04-07

    In the paper the authors compare the different solid state bonding mechanics for both the processes of hollow profiles extrusion and Friction Stir Welding (FSW), through the results obtained from a wide experimental campaign on AA6082-T6 aluminum alloys. Microstructure evaluation, tensile tests and micro-hardness measurements realized on specimens extracted by samples of the two processes are discussed also by means of the results obtained from coupled FEM simulation of the processes.

  8. Low-aluminum content iron-aluminum alloys

    SciTech Connect

    Sikka, V.K.; Goodwin, G.M.; Alexander, D.J.

    1995-06-01

    The low-aluminum-content iron-aluminum program deals with the development of a Fe-Al alloy with aluminum content such as a produce the minimum environmental effect at room temperature. The FAPY is an Fe-16 at. % Al-based alloy developed at the Oak Ridge National Laboratory as the highest aluminum-containing alloy with essentially no environmental effect. The chemical composition for FAPY in weight percent is: aluminum = 8.46, chromium = 5.50, zirconium = 0.20, carbon = 0.03, molybdenum = 2.00, yttrium = 0.10 and iron = 83.71. The ignots of the alloy can be hot worked by extrusion, forging, and rolling processes. The hot-worked cast structure can be cold worked with intermediate anneals at 800{degrees}C. Typical room-temperature ductility of the fine-grained wrought structure is 20 to 25% for this alloy. In contrast to the wrought structure, the cast ductility at room temperature is approximately 1% with a transition temperature of approximately 100 to 150{degrees}C, above which ductility values exceed 20%. The alloy has been melted and processed into bar, sheet, and foil. The alloy has also been cast into slabs, step-blocks of varying thicknesses, and shapes. The purpose of this section is to describe the welding response of cast slabs of three different thicknesses of FAPY alloy. Tensile, creep, and Charpy-impact data of the welded plates are also presented.

  9. The Igwisi Hills extrusive 'kimberlites'

    NASA Technical Reports Server (NTRS)

    Reid, A. M.; Donaldson, C. H.; Dawson, J. B.; Brown, R. W.; Ridley, W. I.

    1975-01-01

    The petrography and mineral chemistry of volcanic rocks from the Igwisi Hills in Tanzania are discussed. There is considerable evidence to suggest that the Igwisi rocks are extrusive kimberlites: a two-component nature with high P-T minerals in a low P-T matrix; the presence of chrome pyrope, Al enstatite, chrome diopside, chromite and olivine; a highly oxidized, volatile-rich matrix with serpentine, calcite, magnetite, perovskite; high Sr, Zr, and Nb contents; occurrence in a narrow isolated vent within a stable shield area. The Igwisi rocks differ from kimberlite in the lack of magnesian ilmenite, the scarcity of matrix phlogopite, and the overall low alkali content. They apparently contain material from phlogopite-bearing garnet peridotites with a primary mineral assemblage indicative of equilibrium at upper mantle temperatures and pressures. This primary assemblage was brought rapidly to the surface in a gas-charged, carbonate-rich fluid. Rapid upward transport, extrusion, and rapid cooling have tended to prevent reaction between inclusions and the carbonate-rich matrix that might otherwise have yielded a more typical kimberlite.

  10. Extrusion processing of main commercial legume pulses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extrusion is used commercially to produce high value breakfast and snack foods based on cereals such as wheat or corn. However, this processing method is not being commercially used for legume pulses seeds due to the perception that they do not expand well in extrusion. The rise in consumer demand f...

  11. The effect of extrusion processing on zein

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extrusion processing has been carried out on zein where extrusion temperatures were varied between 100 and 300 deg. C. By differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) thermal degradation begins around 220 deg. C. The color of the extrudate changed the most above tempe...

  12. Hydrostatic extrusion of BSCCO/Ag composite wire

    SciTech Connect

    Bingert, J.F.; Bingham, B.L.; Sebring, R.J.; Kelly, A.M.

    1995-03-01

    The application of hydrostatic extrusion processing to composite wire fabrication offers several advantages over conventional reduction techniques. These include enhanced uniformity, increased reduction capability, and successful extrusion of normally brittle materials. Specifically, this work involved an experiment to screen the effects of seven extrusion process parameters on the uniformity and density of as-extruded BSCCO-core wire, and the required extrusion pressure. Results suggest the following factors to be potentially significant: (1) back pressure, extrusion ratio, and die angle on core uniformity, (2) packing method, extrusion ratio, silver powder additions, and temperature on density, and (3) extrusion ratio and temperature on extrusion pressure.

  13. Analysis and modeling of hot extrusion die for its service life enhancement

    NASA Astrophysics Data System (ADS)

    Akhtar, Syed Sohail

    Aluminum extrusion finds extensive application in the construction, automobile and aerospace industries. High pressures, elevated temperatures, complex and intricate section geometries lead to repeated mechanical and thermal stresses in the die and affiliated tooling. Product rework and rejects can be traced back to various defects spread over the die life cycle: die design, die manufacture and heat treatment, process parameters, inprocess die maintenance/correction and, billet type and quality. Therefore, improved and efficient service life of die and related tooling used in the extrusion press is one the most important factors in maximizing productivity and minimizing cost for ensuring the economical efficiency of an aluminum extrusion plant. How often a die has to be scrapped and replaced with a new one directly contributes to the commercial viability of producing a certain profile. The focus of the current work is on three distinct yet inter-related studies pertaining to the improvement of aluminum extrusion die. Study-A (Die Failure Analysis) is an investigation of various modes and critical failure types based on industrial data (Chapter-2 ), examination of failed dies and finite element simulation for identification of critical process parameters and design features in die fatigue-life (Chapter-3). In Study-B (Die Surface Hardening Treatment), two-stage controlled gas nitriding process for H13 steel is evaluated, both experimentally and numerically, in terms of nitrided case morphology and properties (Chapter-4) followed by experimental and numerical investigation of the effects of repeated nitriding (Chapter-5), pre-nitriding surface preparation (Chapter-6) and die profile geometry (Chapter-7) on nitriding performance in regard to die service life. In Study-C (Effect of Billet Quality on Die Life), the effect of billet quality and related influencing extrusion parameters on the die service life is investigated based on industrial data and some regression

  14. The Cryogenic Tensile Properties of an Extruded Aluminum-Beryllium Alloy

    NASA Technical Reports Server (NTRS)

    Gamwell, W. R.

    2002-01-01

    Basic mechanical properties; i.e., ultimate tensile strength, yield strength, percent elongation, and elastic modulus, were obtained for the aluminum-beryllium alloy, AlBeMet162, at cryogenic (-195.5 C (-320 F) and -252.8 C (-423 F)) temperatures. The material evaluated was purchased to the requirements of SAE-AMS7912, "Aluminum-Beryllium Alloy, Extrusions."

  15. Modelling highly deformable metal extrusion using SPH

    NASA Astrophysics Data System (ADS)

    Prakash, Mahesh; Cleary, Paul W.

    2015-05-01

    Computational modelling is often used to reduce trial extrusions through accurate defect prediction. Traditionally, metal extrusion is modelled using mesh based finite element methods. However, large plastic deformations can lead to heavy re-meshing and numerical diffusion. Here we use the mesh-less smoothed particle hydrodynamics method since it allows simulation of large deformations without re-meshing and the tracking of history dependent properties such as plastic strain making it suitable for defect prediction. The variation in plastic strain and deformation for aluminium alloy in a cylindrical 3D geometry with extrusion ratio and die angle is evaluated. The extrusion process is found to have three distinct phases consisting of an initial sharp rise in extrusion force, a steady phase requiring constant force and terminating in a sharp decline in force as metal is completely extruded. Deformation and plastic strain increased significantly with extrusion ratio but only moderately with die angle. Extrusion force increased by 150 % as the extrusion ratio increased from 2:1 to 4:1 but had only a marginal change with die angle. A low strain zone in the centre of the extruded product was found to be a function of extrusion ratio but was persistent and did not vary with die angle. Simulation of a complex 3D building industry component showed large variations in plastic strain along the length of the product at two scales. These were due to change in metal behaviour as extrusion progressed from phase 1 to phase 2. A stagnation zone at the back of the die was predicted that could lead to the "funnel" or "pipe" defect.

  16. A Study of Tube Extrusion Process

    SciTech Connect

    Haghighat, H.; Mohammadinoori, S.

    2011-01-17

    An upper bound solution for tube extrusion is developed in this paper. The dead zone is assumed to have the sine profile and a kinematically admissible velocity field is proposed. From the proposed velocity field, the upper bound solution on relative punch pressure and extrusion load is determined with respect to chosen process parameters. The results are compared with theoretical and experimental results from a reference to illustrate the validity of the proposed velocity field. This indicates that the analysis presented here renders better upper bound solution than that given by Ebrahimi et al.. [An upper-bound analysis of the tube extrusion process (2008) J. Mater. Process. Technol. 99:214-220].

  17. Extrusion resistance of elastomers and plastic materials

    SciTech Connect

    Kosty, J.

    1984-02-01

    In today's oil production equipment, sealing systems are required to withstand high pressures and temperatures without extruding. The variety of seal shapes and of operating conditions makes it necessary to characterize the extrusion resistance of seal materials so that the component design engineer can select the proper seal system for the application. This paper will present a unique test method for measuring the extrusion characteristics of elastomeric and thermoplastic seal material at various temperature, pressure, and gap conditions. Data will be presented to illustrate the effect of elastomeric extrusion of seals of different sizes and the effect of concentric and eccentric gaps. Data will also be presented for acceptable extrusion characteristics of thermoplastic backups.

  18. HIGH ENERGY RATE EXTRUSION OF URANIUM

    DOEpatents

    Lewis, L.

    1963-07-23

    A method of extruding uranium at a high energy rate is described. Conditions during the extrusion are such that the temperature of the metal during extrusion reaches a point above the normal alpha to beta transition, but the metal nevertheless remains in the alpha phase in accordance with the Clausius- Clapeyron equation. Upon exiting from the die, the metal automatically enters the beta phase, after which the metal is permitted to cool. (AEC)

  19. Transpalpebral extrusion of solid silicone buckle.

    PubMed

    Khan, Abadan Amitava

    2009-05-01

    Explants used in retinal reattachment surgery occasionally extrude. Cheese-wiring of the suture through the sclera consequent to raised intraocular pressure allows the buckle to loosen and/or unfold. Subsequent infection, often with Staphylococcus albus, accelerates the process of extrusion. Commonly, such explants are of silicone sponge. The reported case is unusual in that the extrusion occurred through the upper lid, and involved a solid silicone explant. PMID:20671837

  20. Transpalpebral extrusion of solid silicone buckle

    PubMed Central

    Khan, Abadan Amitava

    2009-01-01

    Explants used in retinal reattachment surgery occasionally extrude. Cheese-wiring of the suture through the sclera consequent to raised intraocular pressure allows the buckle to loosen and/or unfold. Subsequent infection, often with Staphylococcus albus, accelerates the process of extrusion. Commonly, such explants are of silicone sponge. The reported case is unusual in that the extrusion occurred through the upper lid, and involved a solid silicone explant. PMID:20671837

  1. Extrusion and Extruded Products: Changes in Quality Attributes as Affected by Extrusion Process Parameters: A Review.

    PubMed

    Alam, M S; Kaur, Jasmeen; Khaira, Harjot; Gupta, Kalika

    2016-01-01

    Extrusion of foods is an emerging technology for the food industries to process and market a large number of products of varying size, shape, texture, and taste. Extrusion cooking technology has led to production of wide variety of products like pasta, breakfast cereals, bread crumbs, biscuits, crackers, croutons, baby foods, snack foods, confectionery items, chewing gum, texturized vegetable protein (TVP), modified starch, pet foods, dried soups, dry beverage mixes etc. The functional properties of extruded foods plays an important role for their acceptability which include water absorption, water solubility, oil absorption indexes, expansion index, bulk density and viscosity of the dough. The aim of this review is to give the detailed outlines about the potential of extrusion technology in development of different types of products and the role of extrusion-operating conditions and their effect on product development resulting in quality changes i.e physical, chemical, and nutritional, experienced during the extrusion process. PMID:25574813

  2. 3D FEM Geometry and Material Flow Optimization of Porthole-Die Extrusion

    SciTech Connect

    Ceretti, Elisabetta; Mazzoni, Luca; Giardini, Claudio

    2007-05-17

    The aim of this work is to design and to improve the geometry of a porthole-die for the production of aluminum components by means of 3D FEM simulations. In fact, the use of finite element models will allow to investigate the effects of the die geometry (webs, extrusion cavity) on the material flow and on the stresses acting on the die so to reduce the die wear and to improve the tool life. The software used to perform the simulations was a commercial FEM code, Deform 3D. The technological data introduced in the FE model have been furnished by METRA S.p.A. Company, partner in this research. The results obtained have been considered valid and helpful by the Company for building a new optimized extrusion porthole-die.

  3. Aluminum Analysis.

    ERIC Educational Resources Information Center

    Sumrall, William J.

    1998-01-01

    Presents three problems based on the price of aluminum designed to encourage students to be cooperative and to use an investigative approach to learning. Students collect and synthesize information, analyze results, and draw conclusions. (AIM)

  4. Aluminum Hydroxide

    MedlinePlus

    ... penicillamine (Cuprimine, Depen), prednisone (Deltasone, Orasone), products containing iron, tetracycline (Sumycin, Tetracap, and others), ticlopidine (Ticlid), and vitamins.be aware that aluminum hydroxide may interfere with other medicines, making them less effective. Take your other medications 1 ...

  5. Recrystallization behaviour of AA6063 extrusions

    NASA Astrophysics Data System (ADS)

    Zhang, K.; Pettersen, T.; Paulsen, C. O.; Marthinsen, K.; Holmedal, B.; Segatori, A.

    2015-08-01

    Cylindrical profiles of an AA6063 aluminium alloy were produced in a lab-scale direct extrusion set-up. The extrusion was performed at 300 °C, 450 °C and 550 °C, respectively, with the same ram speed. Immediate water quenching was applied to the profiles and the end of billet (butt-end) after extrusion. Microstructure and texture of the material in different states were measured by electron back-scattered diffraction. Only the profile extruded at 300 °C, was found in the deformed state after extrusion, featuring a fibrous grain structure and a strong <111> and weak <100> double fibre texture. Post-extrusion annealing of this profile at 450 °C resulted in an almost fully recrystallized structure (recrystallized fraction of 87%) and with a texture similar to that of the as-deformed state. The profile extruded at 450 °C was almost fully recrystallized (recrystallization fraction 91%) already after quenching, and with a texture characterized by a weak <111> and strong <100> double fibre. The profile extruded at 550 °C showed a partially recrystallized grain structure with recrystallization fraction of 71%, and with a texture dominated by a <100> fibre. The influence of the deformation conditions on the recrystallization behaviour, in terms of recrystallization kinetics and mechanisms, are discussed in view of these results.

  6. Process optimization for continuous extrusion wet granulation.

    PubMed

    Tan, Li; Carella, Anthony J; Ren, Yukun; Lo, Julian B

    2011-08-01

    Three granulating binders in high drug-load acetaminophen blends were evaluated using high shear granulation and extrusion granulation. A polymethacrylate binder enhanced tablet tensile strength with rapid disintegration in simulated gastric fluid, whereas polyvinylpyrrolidone and hydroxypropyl cellulose binders produced less desirable tablets. Using the polymethacrylate binder, the extrusion granulation process was studied regarding the effects of granulating liquid, injection rate and screw speed on granule properties. A full factorial experimental design was conducted to allow the statistical analysis of interactions between extrusion process parameters. Response variables considered in the study included extruder power consumption (screw loading), granule bulk/tapped density, particle size distribution, tablet hardness, friability, disintegration time and dissolution. PMID:20367553

  7. Intervertebral disc extrusion in six cats.

    PubMed

    Knipe, M F; Vernau, K M; Hornof, W J; LeCouteur, R A

    2001-09-01

    Existing reports concerning intervertebral disc disease (IVDD) have focused almost exclusively on dogs, although a small number of individual case reports of IVDD of cats has been published. The medical records of six cats with IVDD were reviewed. Radiographic studies confirmed narrowed intervertebral disc spaces, mineralised intervertebral discs, and one or more extradural compressive lesions of the spinal cord in each cat. All disc extrusions were located in the thoracolumbar region. Surgical decompression of the spinal cord was achieved in all cats by means of hemilaminectomy and removal of compressive extradural material confirmed to be degenerative disc material. Good to excellent neurological recovery was noted in five of the six cats included in this report. Based on this review, it appears that IVDD of cats has many similarities to IVDD of dogs, and that healthy cats with acute intervertebral disc extrusion(s) respond favourably to surgical decompression of the spinal cord. PMID:11876633

  8. Progression of a lumbar disc extrusion.

    PubMed

    Crowell, Michael S; Alitz, Curtis

    2014-11-01

    The patient was a 34-year-old woman who was referred to a physical therapist for a chief complaint of progressively worsening right buttock pain with paresthesias of the right posterior thigh and calf. Prior magnetic resonance imaging of the patient's lumbar spine revealed a large left paracentral disc extrusion at L5-S1. Following physical therapist intervention, the patient reported a new onset of left posterior thigh pain, with paresthesias of the dorsolateral aspect of the left foot. Repeat magnetic resonance imaging of the patient's lumbar spine revealed an increase in the size of the disc extrusion at L5-S1. PMID:25361862

  9. Aluminum alloy

    NASA Technical Reports Server (NTRS)

    Blackburn, Linda B. (Inventor); Starke, Edgar A., Jr. (Inventor)

    1989-01-01

    This invention relates to aluminum alloys, particularly to aluminum-copper-lithium alloys containing at least about 0.1 percent by weight of indium as an essential component, which are suitable for applications in aircraft and aerospace vehicles. At least about 0.1 percent by weight of indium is added as an essential component to an alloy which precipitates a T1 phase (Al2CuLi). This addition enhances the nucleation of the precipitate T1 phase, producing a microstructure which provides excellent strength as indicated by Rockwell hardness values and confirmed by standard tensile tests.

  10. Effects of extrusion conditions on the extrusion responses and the quality of brown rice pasta.

    PubMed

    Wang, Li; Duan, Wei; Zhou, Sumei; Qian, Haifeng; Zhang, Hui; Qi, Xiguang

    2016-08-01

    This research investigated the effects of extrusion temperature and screw speed on the extrusion system parameters and the qualities of brown rice pasta. The die pressure and motor torque value reached a maximum at 90°C but decreased when the screw speed increased from 80 to 120rpm. The extrusion temperature and screw speed also significantly affected the cooking quality and textural properties of brown rice pasta. The pasta produced at an extrusion temperature of 120°C and screw speed of 120rpm had the best quality with a cooking loss, hardness and adhesiveness of 6.7%, 2387.2g and -7.0g⋅s, respectively, similar to those of pasta made from gluten-free flour. The results indicated that brown rice can be used to produce gluten-free pasta with improved nutrition. PMID:26988508

  11. Impact of various extrusion processes on zein

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Corn protein (zein) is one of the main co-products of corn bio-ethanol production. Extrusion processing of zein continues to be the preferred route to provide improved articles having lower cost and improved properties. There is a lack of information regarding the conditions which can be employed to...

  12. Improved corn protein (zein) extrusion processing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Melt processing using a single and twin screw extruder has been carried out on zein where extrusion temperatures were varied between 100ºC and 300ºC. In addition, melt reprocessing (up to seven times) of zein was undertaken using a single screw extruder. Differential scanning calorimetry (DSC) and t...

  13. Effect of multiple extrusion passes on zein

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zein was repeatedly processed up to seven times using a single screw extruder at a temperature of 145 °C and at approximately 15 grams per minute to determine the extent of degradation that occurs with multiple extrusion passes. SDS-PAGE shows that with the second pass, and each additional pass, the...

  14. Reactive Extrusion of Zein with Glyoxal

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cross-linked zein has been produced using glyoxal as the cross-linking reagent via reactive extrusion for the first time in a twin screw extruder using dilute sodium hydroxide as catalyst. Tri(ethylene glycol) was used as a plasticizer for various items. The extrudate was then ground and processed...

  15. Aluminum phosphide

    Integrated Risk Information System (IRIS)

    Aluminum phosphide ; CASRN 20859 - 73 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinoge

  16. Manufacturing of SiCp Reinforced Magnesium Composite Tubes by Hot Extrusion Processes

    NASA Astrophysics Data System (ADS)

    Hwang, Yeong-Maw; Huang, Song-Jeng; Huang, Yu-San

    2011-05-01

    Magnesium alloys have higher specific strength compared with other metals, such as aluminum, copper and steel. Nevertheless, their ductility is still not good for further metal forming and their strength is not large enough for real structure applications. The aim of this paper is to develop magnesium alloy composite tubes reinforced with SiC particulates by the stir-casting method and hot extrusion processes. At first, AZ61/SiCp composite ingots reinforced with 5 wt% SiC particulates are fabricated by the melt-stirring technique. Then, finite element simulations are conducted to analyze the plastic flow of magnesium alloy AZ61 within the die and the temperature distribution of the products. AZ61/SiCp composite tubes are manufactured by hot extrusion using a specially designed die-set for obtaining uniform thickness distribution tubes. Finally, the mechanical properties of the reinforced AZ61/SiCp composite and Mg alloy AZ61 tubes are compared with those of the billets to manifest the advantages of extrusion processes and reinforcement of SiC particulates. The microstructures of the billet and extruded tubes are also observed. Through the improvement of the strength of the tube product, its life cycle can be extended and the energy consumption can be reduced, and eventually the environmental sustainability is achieved.

  17. Manufacturing of SiCp Reinforced Magnesium Composite Tubes by Hot Extrusion Processes

    SciTech Connect

    Hwang, Yeong-Maw; Huang, Song-Jeng; Huang, Yu-San

    2011-05-04

    Magnesium alloys have higher specific strength compared with other metals, such as aluminum, copper and steel. Nevertheless, their ductility is still not good for further metal forming and their strength is not large enough for real structure applications. The aim of this paper is to develop magnesium alloy composite tubes reinforced with SiC particulates by the stir-casting method and hot extrusion processes. At first, AZ61/SiCp composite ingots reinforced with 5 wt% SiC particulates are fabricated by the melt-stirring technique. Then, finite element simulations are conducted to analyze the plastic flow of magnesium alloy AZ61 within the die and the temperature distribution of the products. AZ61/SiCp composite tubes are manufactured by hot extrusion using a specially designed die-set for obtaining uniform thickness distribution tubes. Finally, the mechanical properties of the reinforced AZ61/SiCp composite and Mg alloy AZ61 tubes are compared with those of the billets to manifest the advantages of extrusion processes and reinforcement of SiC particulates. The microstructures of the billet and extruded tubes are also observed. Through the improvement of the strength of the tube product, its life cycle can be extended and the energy consumption can be reduced, and eventually the environmental sustainability is achieved.

  18. The processing and properties of discontinuously reinforced aluminum composites

    SciTech Connect

    Geiger, A.L.; Walker, J.A. )

    1991-08-01

    Discontinuously-reinforced aluminum (DRA) SiC whisker or particle-reinforced Al-alloy matrix composites produced by P/M methods have progressed toward commercial applications, supported by growing data bases and large-scale production facilities. Attention is presently given to the elastic modulus, plastic, ductile, and toughness characteristics of representative DRA formulations, as well as to the DRAs commercially available in the forms of sheets, extrusions, and optical and instrument grade structures able to supplant beryllium. 36 refs.

  19. TIG welding of aluminum alloys for the APS storage ring - a UHV application

    SciTech Connect

    Goeppner, G.A.

    1996-05-29

    The Advanced Photon Source (APS) incorporates a 7-GeV positron storage ring 1104 meters in circumference. The storage ring vacuum system is designed to maintain a pressure of 1 nTorr or less with a circulating current of 300 mA to enable beam lifetimes of greater than 10 hours. The vacuum chamber is an aluminum extrusion of 6063T5 alloy. There are 235 separate aluminum vacuum chambers in the storage ring connected by stainless steel bellows assemblies. Aluminum was chosen for the vacuum chamber because it can be economically extruded and machined, has good thermal conductivity, low thermal emissivity, a low outgassing rate, low residual radioactivity, and is non-magnetic. The 6063 aluminum-silicon-magnesium alloy provides high strength combined with good machining and weldability characteristics. The extrusion process provides the interior surface finish needed for the ultrahigh vacuum (UHV) environments There are six different vacuum chambers with the same extrusion cross section. The average vacuum chamber length is 171.6 inches. The extruded vacuum chambers are welded to flange assemblies made up of machined 2219 aluminum alloy pieces and 2219 aluminum vacuum flanges from a commercial source.

  20. Breast implant extrusion related to Herpesviridae

    PubMed Central

    Thayabaran, Darmiga; Saiyed, Abrar; Huws, Anita Maria; Khawaja, Saira; Holt, Simon

    2015-01-01

    Introduction We present a case of wound dehiscence in a patient with clinical features of herpes zoster. Presentation of case A 44 year old woman, with a history of recurrent herpes zoster infection, presented to the accident and emergency department with the extrusion of a left sided tear-drop shaped euro-silicone breast implant from an old surgical scar. A month prior to admission, this patient had developed unilateral crops of vesicles along the surgical scar which was apposing her left infra-mammary fold. This was preceded by fatigue and neuralgia. Histology revealed acute inflammation related to a probable Herpesviridae infection. Discussion In this report we discuss the first case of a viral infection predisposing to a wound dehiscence occurring in an old surgical scar. Conclusion This case report illustrates the real but rare possibility of recurrent herpes zoster causing gradual thinning of an old surgical scar. This resulted in an extrusion of the underlying breast implant. PMID:26313335

  1. Equal Channel Angular Extrusion of AA 6063 Using Conventional Direct Extrusion Press

    NASA Astrophysics Data System (ADS)

    Liu, Cheng-Hsien; Lin, Hsin-Chih

    2015-11-01

    In the present work, an extrusion-equal channel angular extrusion (Ex-ECAE) process composed of two processes, extrusion and ECAE, is developed. The Ex-ECAE die contains three segments and is used directly in the conventional direct extrusion press to refine the microstructure, specifically the coarse grain layer (CGL) on the surface of the extrudate. The first segment in the die is designed to perform the normal extrusion process and the second and third segments to perform the process of ECAE. The study reveals that the CGL can be eliminated (refined) completely at the macroscale. At the microscale, the original grain is subdivided into subgrain, which contains many smaller cells. The results can be explained by the grain subdivision mechanism. The textures of the Ex-ECAE sample at various segments are measured using EBSD (Electron Backscatter Diffraction). The results reveal that the first segment of the Ex-ECAE sample has a perfect fiber texture which consists of a mixture of strong <001> and weak <111> fiber components. The texture of the second segment is a mixture of strong (1 1 0) [1 -2 1] and weak (0 1 1) [2 -1 0] fiber components. However, the main component of the second segment is a typical texture of the "alloy" or "brass" type. Finally, the texture of the extrudate (the third segment) is reversed to an incomplete fiber texture which consists of strong (0 0 1) [-1 -1 0] and weak (1 1 1) [1 -1 0].

  2. Dynamic-tensile-extrusion response of fluoropolymers

    SciTech Connect

    Brown, Eric N; Trujillo, Carl P; Gray, George T

    2009-01-01

    The current work applies the recently developed Dynamic-Tensile-Extrusion (Dyn-Ten-Ext) technique to polytetrafluoroethylene (PTFE) and polychlorotrifluoroethylene (PCTFE). Similar to the Taylor Impact Rod, Dynamic-Tensile-Extrusion is a strongly integrated test, probing a wide range of strain rates and stress states. However, the stress state is primarily tensile enabling investigation of dynamic tensile failure modes. Here we investigate the influence of this propensity to neck or not between PCTFE and PTFE on their response under dynamic tensile extrusion loading. The results of the Dyn-Ten-Ext technique are compared with two classic techniques. Both polymers have been investigated using Tensile Split Hopkinson Pressure Bar. The quasistatic and dynamic responses of both fluoro-polymers have been extensively characterized. The two polymers exhibit significantly different failure behavior under tensile loading at moderate strain rates. Polytetrafluoroethylene resists formation of a neck and exhibits significant strain hardening. Independent of temperature or strain rate, PTFE sustains true strains to failure of approximately 1.5. Polychlorotrifluoroethylene, on the other hand, consistently necks at true strains of approximately 0.05.

  3. The mechanical behavior of extruded powder aluminum subjected to biaxial loadings at elevated temperature

    SciTech Connect

    Woods, T.O.; Berghaus, D.G.; Peacock, H.B.

    1990-12-31

    The goal of this investigation is to develop a description of the biaxial behavior of extruded powder aluminum at elevated temperature. Specimens made of extruded 101 ALCOA (Aluminum Company of America) powder aluminum and specimens made from 1100 commercial aluminum rod are tested biaxially in tension-torsion and compression-torsion loadings at the extrusion temperature. The powder aluminum is examined microscopically and stereological methods are used to give a quantified description of the material behavior in terms of changes in the laminar powder material structure. A model for the biaxial (tension-torsion) behavior of extruded powder aluminum is developed. This description is consistent with a previous analysis of behavior in pure tension.

  4. The mechanical behavior of extruded powder aluminum subjected to biaxial loadings at elevated temperature

    SciTech Connect

    Woods, T.O.; Berghaus, D.G. ); Peacock, H.B. )

    1990-01-01

    The goal of this investigation is to develop a description of the biaxial behavior of extruded powder aluminum at elevated temperature. Specimens made of extruded 101 ALCOA (Aluminum Company of America) powder aluminum and specimens made from 1100 commercial aluminum rod are tested biaxially in tension-torsion and compression-torsion loadings at the extrusion temperature. The powder aluminum is examined microscopically and stereological methods are used to give a quantified description of the material behavior in terms of changes in the laminar powder material structure. A model for the biaxial (tension-torsion) behavior of extruded powder aluminum is developed. This description is consistent with a previous analysis of behavior in pure tension.

  5. Extrusion cycles during dome-building eruptions

    NASA Astrophysics Data System (ADS)

    de' Michieli Vitturi, M.; Clarke, A. B.; Neri, A.; Voight, B.

    2013-06-01

    We identify and quantify controls on the timescales and magnitudes of cyclic (periodic) volcanic eruptions using the numerical model DOMEFLOW (de' Michieli Vitturi et al., 2010) which was developed by the authors for magma systems of intermediate composition. DOMEFLOW treats the magma mixture as a liquid continuum with dispersed gas bubbles and crystals in thermodynamic equilibrium with the melt and assumes a modified Poiseuille form of the viscous term for fully developed laminar flow in a conduit of cylindrical cross-section. During ascent, magma pressure decreases and water vapor exsolves and partially degasses from the melt as the melt simultaneously crystallizes, causing changes in mixture density and viscosity. Two mechanisms previously proposed to cause periodic eruption behavior have been implemented in the model and their corresponding timescales explored. The first applies a stick-slip model in which motion of a shallow solid plug is resisted by static/dynamic friction, as described in Iverson et al. (2006). For a constant magma supply rate at depth, this mechanism yields cyclic extrusion with timescales of seconds to tens of seconds with values generally depending on assumed friction coefficients. The second mechanism does not consider friction but treats the plug as a high-viscosity Newtonian fluid. During viscous resistance, pressure beneath the degassed plug can increase sufficiently to overcome dome overburden, plug weight, and viscous forces, and ultimately drive the plug from the conduit. In this second model cycle periods are on the order of hours, and decrease with increasing magma supply rate until a threshold is reached, at which point periodicity disappears and extrusion rate becomes steady (vanishingly short periods). Magma volatile content for fixed chamber pressure has little effect on cycle timescales, but increasing volatile content increases mass flow rate and cycle magnitude as defined by the difference between maximum and minimum

  6. Plasmalemma Redox Activity and H+ Extrusion

    PubMed Central

    Marrè, Maria Teresa; Moroni, Anna; Albergoni, Francesco G.; Marrè, Erasmo

    1988-01-01

    Ferricyanide reduction by Elodea densa leaves, in the dark, is associated with: (a) acidification of the medium; (b) decrease (about 0.2-0.3 units) of intracellular pH (measured in cell sap, cytoplasm, and vacuole); (c) depolarization of the transmembrane potential; (d) net efflux of K+ to the medium. Ferricyanide-induced acid secretion is markedly increased by the presence of fusicoccin (FC), and this effect is severely inhibited by the proton pump inhibitors erythrosine B and vanadate. In the presence of ferricyanide FC-induced H+ extrusion no longer requires the presence of K+ in the medium. The (ferricyanide reduced)/(H+ extruded) ratio varies from about 2, in the absence of FC, to about 1 when the toxin is present, and to more than 4, when ATP-driven H+ extrusion is inhibited by erythrosine B or by vanadate. Fusicoccin markedly reduces K+ release to the medium. The ratio (ferricyanide reduced)/(H+ extruded + K+ released) approaches unity under all of the three conditions considered. These results indicate that ferricyanide reduction depends on a plasmalemma system transporting only electrons to the extracellular acceptor, with consequent potential depolarization and cytoplasm acidification. Most of the protons released in the cytoplasm would be secondarily extruded by the ATP-driven pump, stimulated by both intracellular acidification and depolarization. K+ efflux would depend on potential depolarization. PMID:16666112

  7. Dynamic-Tensile-Extrusion of Polyurea

    NASA Astrophysics Data System (ADS)

    Furmanski, Jevan; Cady, Carl; Rae, Philip; Trujillo, Carl; Gray, G. T., III; Brown, Eric

    2011-06-01

    Polyurea was investigated under Dynamic-Tensile-Extrusion (Dyn-Ten-Ext) loading where spherical projectiles were propelled at 440-509 m/s through an extrusion die with an area reduction of 87%. Momentum of the leading edge imposes a rapid tensile deformation on the extruding material. Polyurea is an elastomer with outstanding high-rate tensile performance of interest in the shock regime. Previous Dyn-Ten-Ext work on semi-crystalline polymers (PTFE, PCTFE) resulted in small-scale fragmentation of the polymer, and did not provide clear information on the evolution of tensile damage in those materials. The polyurea behaved very differently; the polymer first extruded a jet of apparently intact material, which then broke down via void formation and coalescence, followed by fibrillation and tearing of the material. Most of the material in the jet elastically retracted back into the die, and only a few fragments of torn material were liberated from the sample. The surface texture of all failed surfaces was rough indicating a considerable amount of energy was absorbed by sub-critical failure mechanisms. It is interesting to note that while damage nucleation appeared pervasive in the extruded jet, the samples were nevertheless recovered largely intact, with limited fragmentation.

  8. Design for aluminum recycling

    SciTech Connect

    Not Available

    1993-10-01

    This article describes the increasing use of aluminum in automobiles and the need to recycle to benefit further growth of aluminum applications by assuring an economical, high-quality source of metal. The article emphasizes that coordination of material specifications among designers can raise aluminum scrap value and facilitate recycling. Applications of aluminum in automobile construction are discussed.

  9. Extrusion of small-diameter, thin-wall tungsten tubing

    NASA Technical Reports Server (NTRS)

    Blankenship, C. P.; Gyorgak, C. A.

    1967-01-01

    Small-diameter, thin-wall seamless tubing of tungsten has been fabricated in lengths of up to 10 feet by hot extrusion over a floating mandrel. Extrusion of 0.50-inch-diameter tubing over 0.4-inch-diameter mandrels was accomplished at temperatures ranging from 3000 degrees to 4000 degrees F.

  10. Preparation of chalcogenide glass fiber using an improved extrusion method

    NASA Astrophysics Data System (ADS)

    Jiang, Chen; Wang, Xunsi; Zhu, Minming; Xu, Huijuan; Nie, Qiuhua; Dai, Shixun; Tao, Guangming; Shen, Xiang; Cheng, Ci; Zhu, Qingde; Liao, Fangxing; Zhang, Peiquan; Zhang, Peiqing; Liu, Zijun; Zhang, Xianghua

    2016-05-01

    We developed the extrusion method to prepare arsenic-free chalcogenide glass fibers with glass cladding. By using the double nested extrusion molds and the corresponding isolated stacked extrusion method, the utilization rate of glass materials was greatly improved compared with the conventional extrusion method. Fiber preforms with optimal stability of core/cladding ratio throughout the 160 mm length were prepared using the developed extrusion method. Typical fiber structure defects between the core/cladding interface, such as bubbles, cracks, and core diameter variation, were effectively eliminated. Ge-Sb-Se/S chalcogenide glasses were used to form a core/cladding pair and fibers with core/cladding structure were prepared by thermally drawing the extruded preforms. The transmission loss, fiber bending loss, and other optical characters of the fibers were also investigated.

  11. Evolution of microstructure and precipitates in 2xxx aluminum alloy after severe plastic deformation

    NASA Astrophysics Data System (ADS)

    Adamczyk-Cieslak, B.; Zdunek, J.; Mizera, J.

    2016-04-01

    This paper investigates the influence of precipitation on the microstructure development in a 2xxx aluminum alloy subjected to hydrostatic extrusion. A three step reduction of the diameter was performed using hydrostatic extrusion (HE) process: from 20mm (initial state) to 10 mm, 5 mm and 3 mm, which corresponds to the logarithmic deformations ɛ = 1.4, ɛ = 2.8 and ɛ = 3.8 respectively. The microstructure and precipitation analysis before and after deformation was performed using transmission electron microscope (TEM), and scanning electron microscopy (SEM). As a result of the tests, a very significant influence of precipitation on the degree of refinement and mechanism of microstructure transformation was stated.

  12. Method of extruding and packaging a thin sample of reactive material including forming the extrusion die

    DOEpatents

    Lewandowski, Edward F.; Peterson, Leroy L.

    1985-01-01

    This invention teaches a method of cutting a narrow slot in an extrusion die with an electrical discharge machine by first drilling spaced holes at the ends of where the slot will be, whereby the oil can flow through the holes and slot to flush the material eroded away as the slot is being cut. The invention further teaches a method of extruding a very thin ribbon of solid highly reactive material such as lithium or sodium through the die in an inert atmosphere of nitrogen, argon or the like as in a glovebox. The invention further teaches a method of stamping out sample discs from the ribbon and of packaging each disc by sandwiching it between two aluminum sheets and cold welding the sheets together along an annular seam beyond the outer periphery of the disc. This provides a sample of high purity reactive material that can have a long shelf life.

  13. Method of extruding and packaging a thin sample of reactive material, including forming the extrusion die

    DOEpatents

    Lewandowski, E.F.; Peterson, L.L.

    1981-11-30

    This invention teaches a method of cutting a narrow slot in an extrusion die with an electrical discharge machine by first drilling spaced holes at the ends of where the slot will be, whereby the oil can flow through the holes and slot to flush the material eroded away as the slot is being cut. The invention further teaches a method of extruding a very thin ribbon of solid highly reactive material such as lithium or sodium through the die in an inert atmosphere of nitrogen, argon, or the like as in a glovebox. The invention further teaches a method of stamping out sample discs from the ribbon and of packaging each disc by sandwiching it between two aluminum sheets and cold welding the sheets together along an annular seam beyond the outer periphery of the disc. This provides a sample of high purity reactive material that can have a long shelf life.

  14. Processing and response of aluminum-lithium alloy composites reinforced with copper-coated silicon carbide particulates

    SciTech Connect

    Khor, K.A.; Cao, Y.; Boey, F.Y.C.; Hanada, K.; Murakoshi, Y.; Sudarshan, T.S.; Srivatsan, T.S.

    1998-02-01

    Lithium-containing aluminum alloys have shown promise for demanding aerospace applications because of their light weight, high strength, and good damage tolerance characteristics. Additions of ceramic reinforcements to an aluminum-lithium alloy can significantly enhance specific strength, and specific modulus while concurrently offering acceptable performance at elevated temperatures. The processing and fabrication of aluminum-lithium alloy-based composites are hampered by particulate agglomeration or clustering and the existence of poor interfacial relationships between the reinforcing phase and the matrix. The problem of distribution of the reinforcing phase in the metal matrix can be alleviated by mechanical alloying. This article presents the results of a study aimed at addressing and improving the interfacial relationship between the host matrix and the reinforcing phase. Copper-coated silicon carbide particulates are introduced as the particulate reinforcing phase, and the resultant composite mixture is processed by conventional milling followed by hot pressing and hot extrusion. The influence of extrusion ration and extrusion temperature on microstructure and mechanical properties was established. Post extrusion processing by hot isostatic pressing was also examined. Results reveal the increase in elastic modulus of the aluminum-lithium alloy matrix reinforced with copper-coated SiC to be significantly more than the mechanically alloyed Al-Li/SiC counterpart. This suggests the possible contributions of interfacial strengthening on mechanical response in direct comparison with a uniform distribution of the reinforcing ceramic particulates.

  15. Extrusion Pretreatment of Lignocellulosic Biomass: A Review

    PubMed Central

    Zheng, Jun; Rehmann, Lars

    2014-01-01

    Bioconversion of lignocellulosic biomass to bioethanol has shown environmental, economic and energetic advantages in comparison to bioethanol produced from sugar or starch. However, the pretreatment process for increasing the enzymatic accessibility and improving the digestibility of cellulose is hindered by many physical-chemical, structural and compositional factors, which make these materials difficult to be used as feedstocks for ethanol production. A wide range of pretreatment methods has been developed to alter or remove structural and compositional impediments to (enzymatic) hydrolysis over the last few decades; however, only a few of them can be used at commercial scale due to economic feasibility. This paper will give an overview of extrusion pretreatment for bioethanol production with a special focus on twin-screw extruders. An economic assessment of this pretreatment is also discussed to determine its feasibility for future industrial cellulosic ethanol plant designs. PMID:25334065

  16. Turbine airfoil fabricated from tapered extrusions

    DOEpatents

    Marra, John J

    2013-07-16

    An airfoil (30) and fabrication process for turbine blades with cooling channels (26). Tapered tubes (32A-32D) are bonded together in a parallel sequence, forming a leading edge (21), a trailing edge (22), and pressure and suction side walls (23, 24) connected by internal ribs (25). The tapered tubes may be extruded without camber to simplify the extrusion process, then bonded along matching surfaces (34), forming a non-cambered airfoil (28), which may be cambered in a hot forming process and cut (48) to length. The tubes may have tapered walls that are thinner at the blade tip (T1) than at the base (T2), reducing mass. A cap (50) may be attached to the blade tip. A mounting lug (58) may be forged (60) on the airfoil base and then machined, completing the blade for mounting in a turbine rotor disk.

  17. Fatigue performance of welded aluminum deck structures

    SciTech Connect

    Haagensen, P.J.; Ranes, M.; Kluken, A.O.; Kvale, I.

    1996-12-01

    Aluminum alloys are used increasingly in load carrying structures where low weight and low maintenance costs are at a premium. Helicopter decks, structures for living quarters and personnel transfer bridges between platforms are examples of offshore applications. While these structures are not usually subjected to high fatigue loads, the increasing use of aluminum in high speed ships, and more recently in highway bridge structures, makes the question of fatigue performance more important. In this paper the fatigue properties of small scale weldments in an AA6005 alloy are compared with the results of fatigue tests on full scale sections of welded extrusions in the same material, which were used in an aluminum bridge deck structure. The fatigue performance is also compared with the fatigue clauses in the new British design code BS8118 for aluminium structures and the proposed Eurocode 9. The prospects of using a new joining technique, friction stir welding (FSW), in the production of large scale panels for deck and ship hull structures is discussed. The FSW process is described briefly, and some fatigue test data are presented.

  18. Eulerian hydrocode modeling of a dynamic tensile extrusion experiment (u)

    SciTech Connect

    Burkett, Michael W; Clancy, Sean P

    2009-01-01

    Eulerian hydrocode simulations utilizing the Mechanical Threshold Stress flow stress model were performed to provide insight into a dynamic extrusion experiment. The dynamic extrusion response of copper (three different grain sizes) and tantalum spheres were simulated with MESA, an explicit, 2-D Eulerian continuum mechanics hydrocode and compared with experimental data. The experimental data consisted of high-speed images of the extrusion process, recovered extruded samples, and post test metallography. The hydrocode was developed to predict large-strain and high-strain-rate loading problems. Some of the features of the features of MESA include a high-order advection algorithm, a material interface tracking scheme and a van Leer monotonic advection-limiting. The Mechanical Threshold Stress (MTS) model was utilized to evolve the flow stress as a function of strain, strain rate and temperature for copper and tantalum. Plastic strains exceeding 300% were predicted in the extrusion of copper at 400 m/s, while plastic strains exceeding 800% were predicted for Ta. Quantitative comparisons between the predicted and measured deformation topologies and extrusion rate were made. Additionally, predictions of the texture evolution (based upon the deformation rate history and the rigid body rotations experienced by the copper during the extrusion process) were compared with the orientation imaging microscopy measurements. Finally, comparisons between the calculated and measured influence of the initial texture on the dynamic extrusion response of tantalum was performed.

  19. Advanced powder metallurgy aluminum alloys via rapid solidification technology

    NASA Technical Reports Server (NTRS)

    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.

  20. Aging Optimization of Aluminum-Lithium Alloy L277 for Application to Cryotank Structures

    NASA Technical Reports Server (NTRS)

    Sova, B. J.; Sankaran, K. K.; Babel, H.; Farahmand, B.; Cho, A.

    2003-01-01

    Compared with aluminum alloys such as 2219, which is widely used in space vehicle for cryogenic tanks and unpressurized structures, aluminum-lithium alloys possess attractive combinations of lower density and higher modulus along with comparable mechanical properties and improved damage tolerance. These characteristics have resulted in the successful use of the aluminum-lithium alloy 2195 for the Space Shuttle External Tank, and the consideration of newer U.S. aluminum-lithium alloys such as L277 and C458 for future space vehicles. A design of experiments aging study was conducted for plate and a limited study on extrusions. To achieve the T8 temper, Alloy L277 is typically aged at 290 F for 40 hours. In the study for plate, a two-step aging treatment was developed through a design of experiments study and the one step aging used as a control. Based on the earlier NASA studies on 2195, the first step aging temperature was varied between 220 F and 260 F. The second step aging temperatures was varied between 290 F and 310 F, which is in the range of the single-step aging temperature. For extrusions, two, single-step, and one two-step aging condition were evaluated. The results of the design of experiments used for the T8 temper as well as a smaller set of experiments for the T6 temper for plate and the results for extrusions will be presented.

  1. Hot extrusion of B2 iron aluminide powders

    NASA Technical Reports Server (NTRS)

    Strothers, S.; Vedula, K.

    1987-01-01

    The objective of the study was to investigate the effect of powder and processing variables on the microstructure and resultant tensile properties of an extruded FeAlZrB alloy. For a given powder particle size, increasing the extrusion temperature from 1250 to 1450 K is found to increase the grain size and produce a more uniform microstructure. At high extrusion temperatures, where grain boundary mobility is high, powder size is not critical in determining the grain size. The addition of Y2O3 dispersion (1 vol pct) by mechanical alloying makes it possible to obtain very fine-grained materials at low and high extrusion temperatures.

  2. Calibrator device for the extrusion of cable coatings

    NASA Astrophysics Data System (ADS)

    Garbacz, Tomasz; Dulebová, Ľudmila; Spišák, Emil; Dulebová, Martina

    2016-05-01

    This paper presents selected results of theoretical and experimental research works on a new calibration device (calibrators) used to produce coatings of electric cables. The aim of this study is to present design solution calibration equipment and present a new calibration machine, which is an important element of the modernized technology extrusion lines for coating cables. As a result of the extrusion process of PVC modified with blowing agents, an extrudate in the form of an electrical cable was obtained. The conditions of the extrusion process were properly selected, which made it possible to obtain a product with solid external surface and cellular core.

  3. Analysis of Solid State Bonding in the Extrusion Process of Magnesium Alloys --Numerical Prediction and Experimental Verification

    NASA Astrophysics Data System (ADS)

    Alharthi, Nabeel H.

    The automotive industry developments focused on increasing fuel efficiency are accomplished by weight reduction of vehicles, which consequently results in less negative environmental impact. Usage of low density materials such as Magnesium alloys is an approach to replace heavier structural components. One of the challenges in deformation processing of Magnesium is its low formability attributed to the hexagonal close packed (hcp) crystal structure. The extrusion process is one of the most promising forming processes for Magnesium because it applies a hydrostatic compression state of stress during deformation resulting in improved workability. Many researchers have attempted to fully understand solid state bonding during deformation in different structural materials such as Aluminum, Copper and other metals and alloys. There is a lack of sufficient understanding of the extrusion welding in these materials as well as very limited knowledge on this subject for hollow profiles made from Magnesium alloys. The weld integrity and the characteristic of the welding microstructure are generally unknown. In this dissertation three related research projects are investigated by using different tools such as microstructure characterization, mechanical testing, thermo-mechanical physical simulation and finite element numerical modeling. Project 1: Microstructure characterization supported by mechanical testing of the extrusion welding regions in Magnesium alloy AM30 extrudate. The microstructure characterization was conducted using Light Optical Microscopy (LOM), in addition to LOM the electron backscattered diffraction (EBSD) technique was implemented to characterize in depth the deformed and welded microstructure. Project 2: Finite element numerical simulation of AM30 extrudate to model different process parameters and their influence on localized state variables such as strain, strain rate, temperature and normal pressure within the weld zone. Project 3: Physical simulation

  4. Encapsulation of orange terpenes investigating a plasticisation extrusion process.

    PubMed

    Tackenberg, Markus W; Krauss, Ralph; Schuchmann, Heike P; Kleinebudde, Peter

    2015-01-01

    Extrusion is widely used for flavour encapsulation. However, there is a lack of process understanding. This study is aimed at improving the understanding of a counter rotating twin screw extrusion process. Orange terpenes as model flavour, maltodextrin and sucrose as matrix materials, and a water feed rate between 4.0% and 5.7% were applied. Product temperatures < 80 °C and specific mechanical energy inputs <260 Wh/kg resulted. Amorphous and partly crystalline samples were obtained. The loss of crystalline sucrose was linked to a dissolution process of the sugar in the available water amount. Melting of the excipients did not arise, resulting in a plasticisation extrusion process. Maximally 67% of the flavour was retained (corresponding to a 4.1% product flavour load). The flavour loss correlated with insufficient mixing during the process and flavour evaporation after extrusion. Based on these results, recommendations for an improved encapsulation process are given. PMID:26052721

  5. Defective apical extrusion signaling contributes to aggressive tumor hallmarks.

    PubMed

    Gu, Yapeng; Shea, Jill; Slattum, Gloria; Firpo, Matthew A; Alexander, Margaret; Mulvihill, Sean J; Golubovskaya, Vita M; Rosenblatt, Jody

    2015-01-01

    When epithelia become too crowded, some cells are extruded that later die. To extrude, a cell produces the lipid, Sphingosine 1-Phosphate (S1P), which activates S1P₂ receptors in neighboring cells that seamlessly squeeze the cell out of the epithelium. Here, we find that extrusion defects can contribute to carcinogenesis and tumor progression. Tumors or epithelia lacking S1P₂ cannot extrude cells apically and instead form apoptotic-resistant masses, possess poor barrier function, and shift extrusion basally beneath the epithelium, providing a potential mechanism for cell invasion. Exogenous S1P₂ expression is sufficient to rescue apical extrusion, cell death, and reduce orthotopic pancreatic tumors and their metastases. Focal Adhesion Kinase (FAK) inhibitor can bypass extrusion defects and could, therefore, target pancreatic, lung, and colon tumors that lack S1P₂ without affecting wild-type tissue. PMID:25621765

  6. Finite Element Analysis of Extrusion of Multifilamentary Superconductor Precursor

    SciTech Connect

    Peng, X.; Sumption, M.D.; Collings, E.W.

    2004-06-28

    The extrusion of multifilamentary superconductor precursor billets has been modeled using finite element analysis. The billet configuration was 6 around 1, with the subelement consisting of Nb rods, and the outer can or sleeve was Cu. Two general cases were investigated, those in which the re-stack rods were initially; (i) round, and (ii) hexed. A thermo-mechanical, elasto-plastic, finite-element method was used to analyze the extrusion process. In this 3D FEM model, the initial state of the billet was assumed to be absent of bonding. A typical die angle (2{alpha}=45 deg.) and a series of extrusion ratios were selected to perform the simulation and the corresponding stress and strain distributions of the two billet variants processed were compared. Based on the stress and deformation created at the rod/rod and rod/sleeve interfaces, the bonding conditions generated through the extrusion were investigated.

  7. Applications of polymer extrusion technology to coal processing

    NASA Technical Reports Server (NTRS)

    Lewis, D. W.

    1981-01-01

    Upon heating, many of the middle-aged bituminous coals exhibit a plasticity very similar to polyethylene for a few minutes. Plastic coal can be extruded, pelletized or molded using common plastics technology and equipment. Investigations concerning the plastic state of coals are conducted with the objective to develop techniques which will make useful commercial applications of this property possible. Experiments which show the characteristics of plastic-state coal are discussed, and problems related to a continuous extrusion of coal are considered. Probably the most significant difference between the continuous extrusion of coal and the extrusion of a thermoplastic polymer is that volatiles are continuously being released from the coal. Attention is given to aspects of dragflow, solids feeding, and melt pumping. Application potentials for plastic coal extrusion might be related to coal gasification, direct liquefaction, and coal combustion.

  8. FORMING TUBES AND RODS OF URANIUM METAL BY EXTRUSION

    DOEpatents

    Creutz, E.C.

    1959-01-27

    A method and apparatus are presented for the extrusion of uranium metal. Since uranium is very brittle if worked in the beta phase, it is desirable to extrude it in the gamma phase. However, in the gamma temperature range thc uranium will alloy with the metal of the extrusion dic, and is readily oxidized to a great degree. According to this patent, uranium extrusion in thc ganmma phase may be safely carried out by preheating a billet of uranium in an inert atmosphere to a trmperature between 780 C and 1100 C. The heated billet is then placed in an extrusion apparatus having dies which have been maintained at an elevated temperature for a sufficient length of time to produce an oxide film, and placing a copper disc between the uranium billet and the die.

  9. Initiator Effects in Reactive Extrusion of Starch Graft Copolymers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Graft copolymers of starch with water-soluble polymers such as polyacrylamide have potential applications including hydrogels, superabsorbents, and thickening agents. Reactive extrusion is a rapid, continuous method for production of starch graft copolymers with high reaction and grafting efficienc...

  10. Aluminum and Young Artists.

    ERIC Educational Resources Information Center

    Anderson, Thomas

    1980-01-01

    The author suggests a variety of ways in which aluminum and aluminum foil can be used in elementary and junior high art classes: relief drawing and rubbing; printing; repousse; sculpture; mobiles; foil sculpture; and three dimensional design. Sources of aluminum supplies are suggested. (SJL)

  11. VIEW OF THE INSTALLATION OF AN EXTRUSION PRESS IN THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF THE INSTALLATION OF AN EXTRUSION PRESS IN THE HIGH BAY AREA OF BUILDING 865. THE EXTRUSION PRESS WAS USED TO PRODUCE CYLINDRICAL BARS, HOLLOW TUBES, AND SHAPES WITH IRREGULAR CROSS-SECTIONS BY FORCING PREHEATED METAL THROUGH A DIE ORIFICE UNDER HIGH PRESSURE. (5/22/70) - Rocky Flats Plant, Metal Research & Development Laboratory, South of Central Avenue at south end of terminus of Ninth Avenue, Golden, Jefferson County, CO

  12. Making Ceramic/Polymer Parts By Extrusion Stereolithography

    NASA Technical Reports Server (NTRS)

    Stuffle, Kevin; Mulligan, A.; Creegan, P.; Boulton, J. M.; Lombardi, J. L.; Calvert, P. D.

    1996-01-01

    Extrusion stereolithography developmental method of computer-controlled manufacturing of objects out of ceramic/polymer composite materials. Computer-aided design/computer-aided manufacturing (CAD/CAM) software used to create image of desired part and translate image into motion commands for combination of mechanisms moving resin dispenser. Extrusion performed in coordination with motion of dispenser so buildup of extruded material takes on size and shape of desired part. Part thermally cured after deposition.

  13. Atraumatic surgical extrusion to improve tooth restorability: A clinical report.

    PubMed

    Kelly, Robert D; Addison, Owen; Tomson, Phillip L; Krastl, Gabriel; Dietrich, Thomas

    2016-06-01

    This clinical report describes the use of an "atraumatic" vertical extraction system to facilitate the restorative treatment of a tooth that would otherwise be considered unrestorable because of subgingival caries. Minimally invasive surgical root extrusion was undertaken using the Benex extraction system, which can provide controlled tooth extrusion with minimal deformation of the bone socket. A carious endodontically treated mandibular premolar was extruded to provide routine restorative treatment and endodontic retreatment. PMID:26803176

  14. Brittle thermoelectric semiconductors extrusion under high hydrostatic pressure

    SciTech Connect

    Sidorenko, N.A.

    1994-08-10

    Origins of strength increase of brittle materials like thermoelectric (TE) semiconductors during plastic deformation under high external pressure are analyzed. TE material stressed state in the process of extrusion is reviewed. Plastic deformation of monocrystalline TE material billet produced by extrusion under sufficiently high external hydrostatic pressure is more uniform than under ordinary ambient pressure and can lead to crack free extruded TE material structure, crystallographic symmetry of which coincides with original billet one. Experimental device realized the scheme of extrusion under high hydrostatic pressure is described. Here extrusion are carrying out in compressed liquid medium. The developed device ensures the value of hydrostatic pressure up to 2 GPa and extrusion temperature interval 300--600 K. Properties of extruded Bi-Sb and Bi-Sb-Te single crystals are also reviewed. Possible application of presented method of extrusion under high hydrostatic pressure to form TE branches with highly accurate cross section for miniature TE coolers or generators is discussed. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  15. Updated Life-Cycle Assessment of Aluminum Production and Semi-fabrication for the GREET Model

    SciTech Connect

    Dai, Qiang; Kelly, Jarod C.; Burnham, Andrew; Elgowainy, Amgad

    2015-09-01

    This report serves as an update for the life-cycle analysis (LCA) of aluminum production based on the most recent data representing the state-of-the-art of the industry in North America. The 2013 Aluminum Association (AA) LCA report on the environmental footprint of semifinished aluminum products in North America provides the basis for the update (The Aluminum Association, 2013). The scope of this study covers primary aluminum production, secondary aluminum production, as well as aluminum semi-fabrication processes including hot rolling, cold rolling, extrusion and shape casting. This report focuses on energy consumptions, material inputs and criteria air pollutant emissions for each process from the cradle-to-gate of aluminum, which starts from bauxite extraction, and ends with manufacturing of semi-fabricated aluminum products. The life-cycle inventory (LCI) tables compiled are to be incorporated into the vehicle cycle model of Argonne National Laboratory’s Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) Model for the release of its 2015 version.

  16. Mitotic chromosome compaction via active loop extrusion

    NASA Astrophysics Data System (ADS)

    Goloborodko, Anton; Imakaev, Maxim; Marko, John; Mirny, Leonid; MIT-Northwestern Team

    During cell division, two copies of each chromosome are segregated from each other and compacted more than hundred-fold into the canonical X-shaped structures. According to earlier microscopic observations and the recent Hi-C study, chromosomes are compacted into arrays of consecutive loops of ~100 kilobases. Mechanisms that lead to formation of such loop arrays are largely unknown. Here we propose that, during cell division, chromosomes can be compacted by enzymes that extrude loops on chromatin fibers. First, we use computer simulations and analytical modeling to show that a system of loop-extruding enzymes on a chromatin fiber self-organizes into an array of consecutive dynamic loops. Second, we model the process of loop extrusion in 3D and show that, coupled with the topo II strand-passing activity, it leads to robust compaction and segregation of sister chromatids. This mechanism of chromosomal condensation and segregation does not require additional proteins or specific DNA markup and is robust against variations in the number and properties of such loop extruding enzymes. Work at NU was supported by the NSF through Grants DMR-1206868 and MCB-1022117, and by the NIH through Grants GM105847 and CA193419. Work at MIT was supported by the NIH through Grants GM114190 R01HG003143.

  17. Chromosome Compaction by Active Loop Extrusion.

    PubMed

    Goloborodko, Anton; Marko, John F; Mirny, Leonid A

    2016-05-24

    During cell division, chromosomes are compacted in length by more than a 100-fold. A wide range of experiments demonstrated that in their compacted state, mammalian chromosomes form arrays of closely stacked consecutive ∼100 kb loops. The mechanism underlying the active process of chromosome compaction into a stack of loops is unknown. Here we test the hypothesis that chromosomes are compacted by enzymatic machines that actively extrude chromatin loops. When such loop-extruding factors (LEF) bind to chromosomes, they progressively bridge sites that are further away along the chromosome, thus extruding a loop. We demonstrate that collective action of LEFs leads to formation of a dynamic array of consecutive loops. Simulations and an analytically solved model identify two distinct steady states: a sparse state, where loops are highly dynamic but provide little compaction; and a dense state, where there are more stable loops and dramatic chromosome compaction. We find that human chromosomes operate at the border of the dense steady state. Our analysis also shows how the macroscopic characteristics of the loop array are determined by the microscopic properties of LEFs and their abundance. When the number of LEFs are used that match experimentally based estimates, the model can quantitatively reproduce the average loop length, the degree of compaction, and the general loop-array morphology of compact human chromosomes. Our study demonstrates that efficient chromosome compaction can be achieved solely by an active loop-extrusion process. PMID:27224481

  18. Orthodontic extrusion of horizontally impacted mandibular molars

    PubMed Central

    Ma, Zhigui; Yang, Chi; Zhang, Shanyong; Xie, Qianyang; Shen, Yuqing; Shen, Pei

    2014-01-01

    Objective: To introduce and evaluate a novel approach in treating horizontally impacted mandibular second and third molars. Materials and methods: An orthodontic technique was applied for treatment of horizontally impacted mandibular second and third molars, which included a push-type spring for rotation first, and then a cantilever for extrusion. There were 8 mandibular third molars (M3s) and 2 second molars (M2s) in this study. Tooth mobility, extraction time, the inclination and parallelism of the impacted tooth, alveolar bone height of the adjacent tooth, and the relationship of impacted M3 and the inferior alveolar nerve (IAN) were evaluated. Results: Two horizontally impacted M2s could be upright in the arch and good occlusal relationships were obtained after treatment. All impacted M3s were successfully separated from the IAN, without any neurologic consequences. The average extraction time was 5 minutes. There was a significant change in the inclination and parallelism of the impacted tooth after treatment. A new bone apposition with the average height of 3.2 mm was noted distal to the adjacent tooth. Conclusions: This two-step orthodontic technique as presented here may be a safe and feasible alternative in management of severely horizontally impacted mandibular molars, which achieves a successful separation of M3s from the IAN and an excellent position for M2s. PMID:25419364

  19. Outgassing measurement of the aluminum alloy UHV chamber

    NASA Technical Reports Server (NTRS)

    Miyamoto, M.; Itoh, T.; Komaki, S.; Narushima, K.; Ishimaru, H.

    1986-01-01

    A large vacuum chamber (580 mm diameter) was fabricated from an aluminum alloy surface treated by a special process normally used on small chambers. The chamber was tested unbaked and baked at various temperatures, pressures, and holding periods. The chamber was filled with N2 gas, and the outgassing rate was measured after one hour. Then the ultimate pressure was measured. Outgassing rates for baked and unbaked groups were compared. It is concluded that the same surface treatment technique can be used on both large and small chambers produced by the same special extrusion process.

  20. Aluminum reference electrode

    DOEpatents

    Sadoway, Donald R.

    1988-01-01

    A stable reference electrode for use in monitoring and controlling the process of electrolytic reduction of a metal. In the case of Hall cell reduction of aluminum, the reference electrode comprises a pool of molten aluminum and a solution of molten cryolite, Na.sub.3 AlF.sub.6, wherein the electrical connection to the molten aluminum does not contact the highly corrosive molten salt solution. This is accomplished by altering the density of either the aluminum (decreasing the density) or the electrolyte (increasing the density) so that the aluminum floats on top of the molten salt solution.

  1. Aluminum reference electrode

    DOEpatents

    Sadoway, D.R.

    1988-08-16

    A stable reference electrode is described for use in monitoring and controlling the process of electrolytic reduction of a metal. In the case of Hall cell reduction of aluminum, the reference electrode comprises a pool of molten aluminum and a solution of molten cryolite, Na[sub 3]AlF[sub 6], wherein the electrical connection to the molten aluminum does not contact the highly corrosive molten salt solution. This is accomplished by altering the density of either the aluminum (decreasing the density) or the electrolyte (increasing the density) so that the aluminum floats on top of the molten salt solution. 1 fig.

  2. Aluminum: Recycling of Aluminum Dross/Saltcake

    SciTech Connect

    Blazek, S.

    1999-01-29

    As this NICE3 publication details, the objective of this project is to commercialize the process technology to eliminate all landfill waste associated with black dross and saltcake generated from aluminum recycling in the United States.

  3. Aluminum powder metallurgy processing

    NASA Astrophysics Data System (ADS)

    Flumerfelt, Joel Fredrick

    In recent years, the aluminum powder industry has expanded into non-aerospace applications. However, the alumina and aluminum hydroxide in the surface oxide film on aluminum powder require high cost powder processing routes. A driving force for this research is to broaden the knowledge base about aluminum powder metallurgy to provide ideas for fabricating low cost aluminum powder components. 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). The commercial atomization methods are bench marks of current aluminum powder technology. The GARS process is a laboratory scale inert gas atomization facility. A benefit of using pure aluminum powders is an unambiguous interpretation of the results without considering the effects of alloy elements. 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 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

  4. Mechanical Properties of Solid-State Recycled 4xxx Aluminum Alloy Chips

    NASA Astrophysics Data System (ADS)

    Tokarski, Tomasz

    2016-06-01

    The direct production of aluminum from bauxite ores is known to be a very energetic-intensive operation compared to other metallurgical processes. Due to energy issues and the rapid increase in aluminum demand, new kinds of aluminum production processes are required. Aluminum waste recycling, which has an advantage of lowering the cost of electric power consumption, is considered to be an alternative route for material manufacturing. In this work, the way of reusing aluminum EN-AC 44000 alloy scraps by hot extrusion was presented. Metal chips of different sizes and morphology were cold compacted into billet form and then hot extruded. Mechanical properties investigations combined with microstructure observations were performed. Mechanical anisotropy behavior of material was evaluated on the base of tensile test experiments performed on samples machined at 0°, 45°, and 90°, respectively, to the extrusion direction. It was found that the initial size of the chips has an influence on the mechanical properties of the received profiles. Samples produced from fine chips revealed higher tensile strength in comparison to larger chips, which can be attributed to a refined microstructure containing fine, hard Si particles and Fe-rich intermetallic phases. Finally, it was found that anisotropic behavior of chip-based profiles is similar to conventionally cast and extruded materials which prove good bonding quality between chips.

  5. 78 FR 67115 - Aluminum Extrusions From the People's Republic of China: Intent To Rescind 2012 Countervailing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-08

    ... Suspended Investigation; Opportunity To Request Administrative Review, 78 FR 25420, 25424 (May 1, 2013). \\2..., 78 FR 38924 (June 28, 2013) (Initiation Notice). \\4\\ See Letter from Hong Kong Gree regarding ``No... India: Rescission of Countervailing Duty Administrative Review, 77 FR 19634 (April 2, 2012); see...

  6. 77 FR 65671 - Aluminum Extrusions From the People's Republic of China: Notice of Partial Rescission of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-30

    ... FR 25679 (May 1, 2012). \\2\\ See Initiation of Antidumping and Countervailing Duty Administrative Reviews and Request for Revocation in Part, 77 FR 40565 (July 10, 2012) (Initiation). Between June and... Antidumping Duty Administrative Review, 74 FR 21781 (May 11, 2009). Assessment The Department will instruct...

  7. 75 FR 57441 - Aluminum Extrusions From the People's Republic of China: Alignment of Final Countervailing Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-21

    ... Countervailing Duty Investigation, 75 FR 22114 (April 27, 2010) (Initiation), and accompanying Initiation... Investigation, 75 FR 22108 (April 27, 2010). The countervailing and antidumping duty investigations have the... Countervailing Duty Determination, 75 FR 54302 (September 7, 2010). \\1\\ Public and business proprietary...

  8. 78 FR 34649 - Aluminum Extrusions From the People's Republic of China: Preliminary Results of Countervailing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-10

    ..., 76 FR 30653 (May 26, 2011) (Order). \\3\\ See ``Decision Memorandum for Preliminary Results of the...) Zhejiang Xinlong Industry Co., Ltd...... 12.57 20.75 Zhongshan Gold Mountain Aluminium 12.57 20.75 Factory Ltd., Gold Mountain International Development, Limited (collectively, Zhongshan Gold Mountain)...

  9. 75 FR 69403 - Aluminum Extrusions From the People's Republic of China: Notice of Preliminary Determination of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-12

    ... FR 22109 (``Initiation Notice''). \\4\\ See Policy Bulletin 05.1: Separate-Rates Practice and... Antidumping Duty Investigations, 75 FR 51243 (August 19, 2010). Scope of the Investigation The merchandise..., 62 FR 27296, 27323 (May 19, 1997). \\8\\ See Notice of Initiation, 75 FR at 22110. On May 10,...

  10. 76 FR 30653 - Aluminum Extrusions From the People's Republic of China: Countervailing Duty Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-26

    ... From the People's Republic of China: Final Affirmative Countervailing Duty Determination, 76 FR 18521... Affirmative Countervailing Duty Determination, 75 FR 54302 (September 7, 2010) (Preliminary Determination). In...; telephone: 202/482-1009. Case History: On April 4, 2011, the Department published its final determination...

  11. 76 FR 323 - Aluminum Extrusions From the People's Republic of China: Notice of Amended Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-04

    ... Determination of Targeted Dumping, 75 FR 69403 (November 12, 2010) (``Preliminary Determination''). On November... Reviews and Partial Termination of Administrative Reviews, 61 FR 57391, 57392 (November 6, 1996), and... Results of Antidumping Duty Administrative Reviews and Termination in Part, 62 FR 11825 (March 13,...

  12. A new method to maintain lubricant layer in extrusion process

    NASA Astrophysics Data System (ADS)

    Norhayati, A.; Wira, J. Y.; Zin, H. M.; Syahrullail, S.

    2012-06-01

    The present research concerns on the study of the effects of micro-pits arrays formed on the taper die surface. The micro-pits are diamond in shape. The evaluation of micro-pits was carried out by cold forward plane strain extrusion experiments. The experimental results were compared with the results obtained from the plane strain extrusion experimental works with taper die without micro-pits. The lubricant used in this experimental works is additive free paraffinic mineral oil. The experimental results are focusing on the extrusion load, billet surface roughness and grid pattern observation. From the result, the existence of the micro-pits influenced the extrusion load. At the same time, the micro-pits array affected the work piece surface roughness after the extrusion process. The lubricant viscosity also manipulates the quality of work piece after the experiments. From this works, we could conclude that the micro-pits formed on the taper die would create different frictional constraint compared to those without the micro-pits.

  13. Aspects of aluminum toxicity

    SciTech Connect

    Hewitt, C.D.; Savory, J.; Wills, M.R. )

    1990-06-01

    Aluminum is the most abundant metal in the earth's crust. The widespread occurrence of aluminum, both in the environment and in foodstuffs, makes it virtually impossible for man to avoid exposure to this metal ion. Attention was first drawn to the potential role of aluminum as a toxic metal over 50 years ago, but was dismissed as a toxic agent as recently as 15 years ago. The accumulation of aluminum, in some patients with chronic renal failure, is associated with the development of toxic phenomena; dialysis encephalopathy, osteomalacic dialysis osteodystrophy, and an anemia. Aluminum accumulation also occurs in patients who are not on dialysis, predominantly infants and children with immature or impaired renal function. Aluminum has also been implicated as a toxic agent in the etiology of Alzheimer's disease, Guamiam amyotrophic lateral sclerosis, and parkinsonism-dementia. 119 references.

  14. BONDING ALUMINUM METALS

    DOEpatents

    Noland, R.A.; Walker, D.E.

    1961-06-13

    A process is given for bonding aluminum to aluminum. Silicon powder is applied to at least one of the two surfaces of the two elements to be bonded, the two elements are assembled and rubbed against each other at room temperature whereby any oxide film is ruptured by the silicon crystals in the interface; thereafter heat and pressure are applied whereby an aluminum-silicon alloy is formed, squeezed out from the interface together with any oxide film, and the elements are bonded.

  15. Aluminum powder metallurgy processing

    SciTech Connect

    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.

  16. Sediment Core Extrusion Method at Millimeter Resolution Using a Calibrated, Threaded-rod.

    PubMed

    Schwing, Patrick T; Romero, Isabel C; Larson, Rebekka A; O'Malley, Bryan J; Fridrik, Erika E; Goddard, Ethan A; Brooks, Gregg R; Hastings, David W; Rosenheim, Brad E; Hollander, David J; Grant, Guy; Mulhollan, Jim

    2016-01-01

    Aquatic sediment core subsampling is commonly performed at cm or half-cm resolution. Depending on the sedimentation rate and depositional environment, this resolution provides records at the annual to decadal scale, at best. An extrusion method, using a calibrated, threaded-rod is presented here, which allows for millimeter-scale subsampling of aquatic sediment cores of varying diameters. Millimeter scale subsampling allows for sub-annual to monthly analysis of the sedimentary record, an order of magnitude higher than typical sampling schemes. The extruder consists of a 2 m aluminum frame and base, two core tube clamps, a threaded-rod, and a 1 m piston. The sediment core is placed above the piston and clamped to the frame. An acrylic sampling collar is affixed to the upper 5 cm of the core tube and provides a platform from which to extract sub-samples. The piston is rotated around the threaded-rod at calibrated intervals and gently pushes the sediment out the top of the core tube. The sediment is then isolated into the sampling collar and placed into an appropriate sampling vessel (e.g., jar or bag). This method also preserves the unconsolidated samples (i.e., high pore water content) at the surface, providing a consistent sampling volume. This mm scale extrusion method was applied to cores collected in the northern Gulf of Mexico following the Deepwater Horizon submarine oil release. Evidence suggests that it is necessary to sample at the mm scale to fully characterize events that occur on the monthly time-scale for continental slope sediments. PMID:27585268

  17. A novel polymer extrusion micropelletization process

    NASA Astrophysics Data System (ADS)

    Aquite, William

    Polymer micropellets provide a variety of potential applications for different processes in the polymer industry. Conventional pellets are in the size range of 2.5 mm to 5 mm, while micropellets are at least ten times smaller, in the size range of 50 μm to 1000 μm. The potential benefits to a processor using micropellets include: high surface to volume ratio, high bulk density, fast and even melting rates in extrusion, improved dry flow properties, faster injection molding cycles, and consequently lower energy consumption during processing. More specialized sintering processes that require polymer powders, such as selective sintering techniques, microporous plastics parts manufacturing, and other powder sintering methods would benefit from the production of polymer micropellets since these exhibit the advantages of pellets yet have a lower average size. This work focuses on the study of a technique developed at the Polymer Engineering Center. The technique uses a microcapillary die for the production of micropellets by causing instabilities in extruded polymer threads deformed using an air stream. Tuning of process conditions allow the development of surface disturbances that promote breakup of the threads into pellets, which are subsequently cooled and collected. Although micropellets with high sphericity and a narrow size distribution can be produced using this technique, minimal changes in process conditions also lead to the production of lenticular pellets as well as pellets, fibers and threads with a wide range of size and shape distributions. This work shows how changing processing conditions achieve a variety of shapes and sizes of micropellets, broadening its application for the production of powders from a variety of polymer resins. Different approaches were used, including dimensional analysis and numerical simulation of the micropelletization process. This research reveals the influence of non-linear viscoelastic effects on the dispersion of a polymer

  18. Diffusion between glass and metals for optical fiber preform extrusion

    NASA Astrophysics Data System (ADS)

    Yeo, Felicia Yan Xin; Zhang, Zhifeng; Kumar Chakkathara Janardhanan Nair, Dileep; Zhang, Yilei

    2015-07-01

    When silica is extruded, diffusion of metal atoms into silica results contamination to the silica being heated, and thus is a serious concern for the glass extrusion process, such as extrusion of glass fiber preform. This paper examines diffusion between fused silica and two high strength metals, the stainless steel SS410 and the superalloy Inconel 718, at 1000 °C and under the normal atmosphere condition by SEM and Electron Dispersion Spectrum. It is found that diffusion occurs between silica and SS410, and at the same time, SS410 is severely oxidized during diffusion experiment. On the contrary, the diffusion between Inconel 718 and silica is unnoticeable, suggesting excellent high temperature performance of Inconel 718 for glass extrusion.

  19. [Orthodontic extrusion preliminary to implantology in the -aesthetic zone].

    PubMed

    Oosterkamp, B C M; Polder, B J

    2015-11-01

    The replacement of a missing tooth in the aesthetic zone by a dental implant is, in many respects, a challenge. In order to restore and maintain bone and soft tissue, various procedures are used varying from the immediate placement of a front tooth implant with minimal tissue grafts to an extensive treatment programme with bone grafting, possibly in combination with connective tissue grafts. Another treatment option is orthodontic extrusion. This procedure makes it possible for bone and soft tissue to be created both horizontally and vertically, as a result of which loss of vertical binding can be compensated and the primary stability of the implant can be guaranteed. The procedure for orthodontic extrusion is described on the basis of a case study. In an interdisciplinary treatment plan, orthodontic extrusion is a viable treatment alternative, which can make the immediate placement of a dental implant in the frontal region possible. PMID:26568999

  20. Microfabrication of three-dimensional filters for liposome extrusion

    NASA Astrophysics Data System (ADS)

    Baldacchini, Tommaso; Nuñez, Vicente; LaFratta, Christopher N.; Grech, Joseph S.; Vullev, Valentine I.; Zadoyan, Ruben

    2015-03-01

    Liposomes play a relevant role in the biomedical field of drug delivery. The ability of these lipid vesicles to encapsulate and transport a variety of bioactive molecules has fostered their use in several therapeutic applications, from cancer treatments to the administration of drugs with antiviral activities. Size and uniformity are key parameters to take into consideration when preparing liposomes; these factors greatly influence their effectiveness in both in vitro and in vivo experiments. A popular technique employed to achieve the optimal liposome dimension (around 100 nm in diameter) and uniform size distribution is repetitive extrusion through a polycarbonate filter. We investigated two femtosecond laser direct writing techniques for the fabrication of three-dimensional filters within a microfluidics chip for liposomes extrusion. The miniaturization of the extrusion process in a microfluidic system is the first step toward a complete solution for lab-on-a-chip preparation of liposomes from vesicles self-assembly to optical characterization.

  1. Carbothermic Aluminum Production Using Scrap Aluminum As A Coolant

    DOEpatents

    LaCamera, Alfred F.

    2002-11-05

    A process for producing aluminum metal by carbothermic reduction of alumina ore. Alumina ore is heated in the presence of carbon at an elevated temperature to produce an aluminum metal body contaminated with about 10-30% by wt. aluminum carbide. Aluminum metal or aluminum alloy scrap then is added to bring the temperature to about 900-1000.degree. C. and precipitate out aluminum carbide. The precipitated aluminum carbide is filtered, decanted, or fluxed with salt to form a molten body having reduced aluminum carbide content.

  2. MTBE OXIDATION BY BIFUNCTIONAL ALUMINUM

    EPA Science Inventory

    Bifunctional aluminum, prepared by sulfating zero-valent aluminum with sulfuric acid, has a dual functionality of simultaneously decomposing both reductively- and oxidatively-degradable contaminants. In this work, the use of bifunctional aluminum for the degradation of methyl te...

  3. Studies on aluminum neurotoxicity

    SciTech Connect

    Cho, S.

    1988-01-01

    This work reports the inhibitory effects of aluminum on glucose-6-phosphate dehydrogenase (G6PD) from yeast and brains. The aluminum contents and several enzyme activities in aluminum-fed rat brain homogenates were compared with those in age-matched control groups. The concentration of aluminum in the homogenates of the aluminum-fed groups were twice of that of the controls. Acetylcholinesterase activities were the same as in both groups but hexokinase and G6PD activities in the aluminum-fed group were about 73% and 70% of the control, respectively. Further studies on the inhibitory effects of aluminum on G6PD were performed with the enzymes purified from human and pig brains. Two forms of G6PD isozymes were purified from human and pig brain by ammonium sulfate fractionation, hydroxylapatite chromatography, affinity chromatography with NADP-agarose and Blue-Sepharose CL-6B, and gel filtration with Sephadex S-300. The two forms of isozymes (isozyme I and II), purified to be homogeneous, had a molecular weight of 220,000, and composed of 4 subunits of molecular weight of 57,000. HPLC peptide maps of tryptic digests and amino acid analyses of the isozymes showed extensive homologies between the isozymes. Interestingly, only the isozyme II in human and pig brain were active with 6-phosphogluconate as a substrate. No such an activity was found in isozyme I. Aluminum inactivated G6PD activity of the human and pig brain isozyme I and isozyme II without affecting the 6-phosphogluconate dehydrogenase activity of the isozyme II. Circular dichroism studies showed that the binding of aluminum to G6PD induced a decrease in {alpha}-helix and {beta}-sheet and a increase in random coil. Therefore it is suggested that inactivation of G6PD by aluminum is due to the conformational change induced by aluminum binding.

  4. Rapid prototyping of extrusion dies using layer-based techniques

    SciTech Connect

    Misiolek, W.Z.; Winther, K.T.; Prats, A.E.; Rock, S.J.

    1999-02-01

    Extrusion die design and development often requires significant craftsman skill and iterative improvement to arrive at a production-ready die geometry. Constructing the dies used during this iterative process from layers, rather than from one solid block of material, offers unique opportunities to improve die development efficiency when coupled with concepts drawn from the rapid prototyping field. This article presents a proof-of-concept illustrating the potential utility of layer-based extrusion dies for the die design and fabrication process. The major benefits include greater flexibility in the design process, a more efficient, automated fabrication technique, and a means for performing localized die modifications and repairs.

  5. The effect of grain size on dynamic tensile extrusion behaviour

    NASA Astrophysics Data System (ADS)

    Park, Leeju; Kim, Hack Jun; Kim, Seok Bong

    2015-09-01

    Dynamic tensile extrusion (DTE) tests were conducted on coarse grained and ultrafine grained (UFG) OFHC Cu, Interstitial free (IF) Steel, and pure Ta. Equal channel angular pressing (ECAP) of 16passes with Bc for Cu, IF Steel and 4 passes for Ta was employed to fabricated UFG materials. DTE tests were carried out by launching the sphere samples (Dia. 7.62 mm) to the conical extrusion die at a speed of ˜500 m/sec. The fragmentation behavior of the soft-recovered fragments were examined and compared with each other. The DTE fragmentation behavior of CG and UFG was numerically simulated by the LS-DYNA FEM code.

  6. Calcium-Dependent Mitochondrial Extrusion in Ciliated Protozoa

    PubMed Central

    Bisharyan, Yelena; Clark, Theodore G.

    2011-01-01

    Here we demonstrate that ciliated protozoa can jettison mitochondria as intact organelles, releasing their contents to the extracellular space either in a soluble form, or in association with membrane vesicles at the cell periphery. The response is triggered by lateral clustering of GPI-anchored surface antigens, or by heat shock. In the first instance, extrusion is accompanied by elevated levels of intracellular calcium and is inhibited by Verapamil and BAPTA-AM arguing strongly for the involvement of calcium in triggering the response. Cells survive mitochondrial discharge raising the interesting possibility that extrusion is an early evolutionary adaptation to cell stress. PMID:21856451

  7. Aluminum: Reducing chloride emissions from aluminum production

    SciTech Connect

    Simon, P.

    1999-09-29

    Reynolds Metals Company (RMC), with assistance from a NICE{sup 3} grant, is developing for commercialization a closed-loop control process that greatly reduces chlorine emissions and increases plant efficiency while maintaining metal quality. The process still utilizes chlorine to remove impurities during aluminum processing, but is more effective than current methods. With the new technology chlorine in the stack is monitored and input chlorine is adjusted continuously. This optimization of chlorine use results in substantially less waste because less chlorine has to be bought or produced by aluminum manufacturers. This innovation is a significant improvement over conventional aluminum treatments, in which chlorine is injected in a more costly and wasteful manner. By the year 2010, the new technology has the potential to reduce the energy it takes to create chlorine by 8.4 billion Btu per year and to cut greenhouse gas emissions by 1,377 tons per year.

  8. A new technique for the strengthening of aluminum tungsten inert gas weld metals: using carbon nanotube/aluminum composite as a filler metal.

    PubMed

    Fattahi, M; Nabhani, N; Rashidkhani, E; Fattahi, Y; Akhavan, S; Arabian, N

    2013-01-01

    The effect of multi-walled carbon nanotube (MWCNT) on the mechanical properties of aluminum multipass weld metal prepared by the tungsten inert gas (TIG) welding process was investigated. High energy ball milling was used to disperse MWCNT in the aluminum powder. Carbon nanotube/aluminum composite filler metal was fabricated for the first time by hot extrusion of ball-milled powders. After welding, the tensile strength, microhardness and MWCNT distribution in the weld metal were investigated. The test results showed that the tensile strength and microhardness of weld metal was greatly increased when using the filler metal containing 1.5 wt.% MWCNT. Therefore, according to the results presented in this paper, it can be concluded that the filler metal containing MWCNT can serve as a super filler metal to improve the mechanical properties of TIG welds of Al and its alloys. PMID:23948441

  9. Effects of processing parameters on the extrusion by continuous variable cross-section direct extrusion with 7A09 aluminium alloy

    NASA Astrophysics Data System (ADS)

    Li, Feng; Wu, Hongbin; Qin, Minghan

    2016-02-01

    In order to study the effects of processing parameters on the continuous variable cross-section direct extrusion (CVCDE), taking 7A09 aluminium alloy for example, the extrusion speed and forming temperature and the friction factor as key processing parameters are applied to research by finite element (FE) simulation. The research result showed that the extrusion speed had a significant influence on the maximum temperature of the billet, at the same time, both decreasing the friction factor and increasing forming temperature within a certain range were beneficial to reduce extrusion load. Both forming temperature and the extrusion speed were inversely linked to extrusion load, but the friction factor was directly proportional to extrusion load. Forming temperature had a far more important influence on extrusion load by comparison: when forming temperature increased from 380∘ to 430∘C, the peak value of extrusion load decreased by 25.6% and the flow uniformity of extruded product got improved. The process window based on both the press limit and surface defects limit was established and the most reasonable forming temperature was 405∘C under this process condition, which provided theoretical basis for formulation process of 7A09 aluminium alloy on the CVCDE extrusion.

  10. Anodizing Aluminum with Frills.

    ERIC Educational Resources Information Center

    Doeltz, Anne E.; And Others

    1983-01-01

    "Anodizing Aluminum" (previously reported in this journal) describes a vivid/relevant laboratory experience for general chemistry students explaining the anodizing of aluminum in sulfuric acid and constrasting it to electroplating. Additions to this procedure and the experiment in which they are used are discussed. Reactions involved are also…

  11. Cast aluminum denture base.

    PubMed

    Barco, M T; Dembert, M L

    1987-08-01

    The laboratory procedures for a cast aluminum base denture have been presented. If an induction casting machine is not available, the "two-oven technique" works well, provided the casting arm is kept spinning manually for 4 minutes after casting. If laboratory procedures are executed precisely and with care, the aluminum base denture can be cast with good results. PMID:3305884

  12. Is the Aluminum Hypothesis Dead?

    PubMed Central

    2014-01-01

    The Aluminum Hypothesis, the idea that aluminum exposure is involved in the etiology of Alzheimer disease, dates back to a 1965 demonstration that aluminum causes neurofibrillary tangles in the brains of rabbits. Initially the focus of intensive research, the Aluminum Hypothesis has gradually been abandoned by most researchers. Yet, despite this current indifference, the Aluminum Hypothesis continues to attract the attention of a small group of scientists and aluminum continues to be viewed with concern by some of the public. This review article discusses reasons that mainstream science has largely abandoned the Aluminum Hypothesis and explores a possible reason for some in the general public continuing to view aluminum with mistrust. PMID:24806729

  13. Factors Contributing to Pilot Valve Fuel Seal Extrusion in Orbiter PRCS Thrusters

    NASA Technical Reports Server (NTRS)

    Waller, J.M.; Saulsberry, R.L.; Albright, John D.

    2000-01-01

    Extrusion of the polytetrafluoroethylene (PTFE) pilot seal used in the monomethylhydrazine (fuel) valve of the Orbiter Primary Reaction Control System (PRCS) thrusters has been implicated in numerous on-orbit thruster failures and on-ground valve failures. Two extrusion mechanisms have been proposed, one or both may be occurring. The first mechanism is attributed to thermal expansion mismatch between adjacent PTFE and metal parts used in the fuel valve, and is referred to as thermal extrusion. The second mechanism is attributed to nitrogen tetroxide (oxidizer) leakage from the adjacent oxidizer valve on the same thruster during ground turnaround, and is referred to as oxidizer-induced extrusion. Model calculations of PTFE pilot seal in an exact pilot valve configuration show that extrusion can be caused by differential thermal expansion, without the intervening influence of oxidizer. Experimental data on semitrapped PTFE and TFM (modified PTFE) specimens simulating a fuel pilot valve configuration show that thermal extrusion 1) is incremental and irreversible, 2) increases with the size of the thermal excursion, 3) decreases with successive thermal cycling, and 4) is accompanied by gap formation. Both PTFE and TFM exhibit a higher affinity for oxidizer than fuel. The property changes associated with oxidizer uptake may explain why oxidizer seals do not exhibit extrusion. Impression replicas of fuel pilot seals removed from the Orbiter fleet show two types of extrusion: extrusion of the entire seal (loaded extrusion), or extrusion of non-sealing surface (unloaded extrusion). Both extrusion types may arise from differences in service history, rather than in failure mechanism. The plausibility oxidizer-induced extrusion was evaluated. Preliminary calculations suggest that enough energy, heat, or gas may be liberated under certain operational scenarios to cause catastrophic extrusion. However, given the lack of supporting data, conclusions implicating oxidizer leakage

  14. The aluminum smelting process.

    PubMed

    Kvande, Halvor

    2014-05-01

    This introduction to the industrial primary aluminum production process presents a short description of the electrolytic reduction technology, the history of aluminum, and the importance of this metal and its production process to modern society. Aluminum's special qualities have enabled advances in technologies coupled with energy and cost savings. Aircraft capabilities have been greatly enhanced, and increases in size and capacity are made possible by advances in aluminum technology. The metal's flexibility for shaping and extruding has led to architectural advances in energy-saving building construction. The high strength-to-weight ratio has meant a substantial reduction in energy consumption for trucks and other vehicles. The aluminum industry is therefore a pivotal one for ecological sustainability and strategic for technological development. PMID:24806722

  15. Aluminum structural applications

    SciTech Connect

    Lucas, G.

    1996-05-01

    Extensive research by aluminum producers and automakers in the 1980s resulted in the development of technologies that enable building of aluminum cars that meet and exceed all the expectations of today`s drivers and passengers, yet weigh several hundred pounds less than their steel counterparts. The Acura NSX sports car, the Audi A8, and the Jaguar XJ220 have all been introduced. Ford has built 40 aluminum-intensive automobiles based on the Taurus/Sable for test purposes, and General Motors recently announced an aluminum-structured electric vehicle. The design flexibility that aluminum allows is shown by these examples. Each uses a somewhat different technology that is particularly suited to the vehicle and its market.

  16. The Aluminum Smelting Process

    PubMed Central

    2014-01-01

    This introduction to the industrial primary aluminum production process presents a short description of the electrolytic reduction technology, the history of aluminum, and the importance of this metal and its production process to modern society. Aluminum's special qualities have enabled advances in technologies coupled with energy and cost savings. Aircraft capabilities have been greatly enhanced, and increases in size and capacity are made possible by advances in aluminum technology. The metal's flexibility for shaping and extruding has led to architectural advances in energy-saving building construction. The high strength-to-weight ratio has meant a substantial reduction in energy consumption for trucks and other vehicles. The aluminum industry is therefore a pivotal one for ecological sustainability and strategic for technological development. PMID:24806722

  17. Melting, casting, and alpha-phase extrusion of the uranium-2. 4 weight percent niobium alloy

    SciTech Connect

    Anderson, R C; Beck, D E; Kollie, T G; Zorinsky, E J; Jones, J M

    1981-10-01

    The experimental details of the melting, casting, homogenization, and alpha-phase extrusion process used to fabricate the uranium-2.4 wt % niobium alloy into 46-mm-diameter rods is described. Extrusion defects that were detected by an ultrasonic technique were eliminated by proper choice of extrusion parameters; namely, reduction ratio, ram speed, die angle, and billet preheat temperature.

  18. Extrusion cooking with glucose supplementation reduced fumonisin concentrations and toxicity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extrusion cooking involves forcing material through a heated barrel under high pressure using one (single-screw configuration) or two (twin-screw configuration) augers. We previously demonstrated (Bullerman et al., Journal of Agricultural and Food Chemistry 56:2400-2405, 2008; Voss et al., Journal o...

  19. PREPARATION OF STARCH-GRAFT-POLYACRYLAMIDE COPOLYMERS BY REACTIVE EXTRUSION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Graft copolymers of starch and polyacrylamide (PAAm) were prepared by reactive extrusion using a co-rotating twin screw extruder and ammonium persulfate initiator. Feed rates were 109 g/min to 325 g/min (all components) at a moisture content of 50%, with screw speeds in the range 100 rpm to 300 rpm...

  20. EXPOSURE TO CHEMICAL ADDITIVES FROM POLYVINYL CHLORIDE POLYMER EXTRUSION PROCESSING

    EPA Science Inventory

    This report presents a model to predict worker inhalation exposure due to off-gassing of additives during polyvinyl chloride (PVC) extrusion processing. ata on off-gassing of additives were reviewed in the literature, the off-gassing at normal PVC processing temperatures was stud...

  1. Load beam unit replaceable inserts for dry coal extrusion pumps

    DOEpatents

    Saunders, Timothy; Brady, John D.

    2012-11-13

    A track assembly for a particulate material extrusion pump according to an exemplary aspect of the present disclosure includes a link assembly with a roller bearing. An insert mounted to a load beam located such that the roller bearing contacts the insert.

  2. Track with overlapping links for dry coal extrusion pumps

    DOEpatents

    Saunders, Timothy; Brady, John D

    2014-01-21

    A chain for a particulate material extrusion pump includes a plurality of links, each of the plurality of links having a link body and a link ledge, wherein each link ledge of the plurality of links at least partially overlaps the link body of an adjacent one of the plurality of links.

  3. Reactive extrusion of zein with glyoxal and polyethylene maleic anhydride

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order for zein, a potentially significant co-product of the bio-ethanol industry, to be used in new markets, improved zein based products are needed. These products need to be produced by the most economical means possible. In the traditional plastics industry, extrusion techniques are the most e...

  4. MODELING EXTRUSION PROCESSING OF AQUACULTURE FEED INCORPORATING DISTILLERS GRAINS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three ingredient blends containing 20, 30, and 40% Distillers Dried Grains with Solubles (DDGS), with a net protein adjusted to 28% were prepared. Extrusion studies were conducted at 3 levels of moisture content, 3 levels of barrel temperature profile, and 5 levels of screw speed in a single screw e...

  5. Peritoneo-vulvar catheter extrusion after shunt operation.

    PubMed

    Nagulic, M; Djordjevic, M; Samardzic, M

    1996-04-01

    We report an unusual case of catheter extrusion through the external genitalia. between the labium majus and the labium minus, in a 6-month-old hydrocephalic baby. The event occurred 5 months after placement of a ventriculoperitoneal shunt. PMID:8739410

  6. PREPARATION OF STARCH-G-POLYACRYLAMIDE COPOLYMERS BY REACTIVE EXTRUSION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Graft copolymers of starch and polyacrylamide were prepared by reactive extrusion using a co-rotating twin screw extruder and ammonium persulfate initiator. Feed rates were 109 g/min up to 325 g/min (all components) at a moisture content of 50 percent, with screw speeds in the range 100 rpm to 300 ...

  7. Clinical biochemistry of aluminum

    SciTech Connect

    King, S.W.; Savory, J.; Wills, M.R.

    1981-05-01

    Aluminum toxicity has been implicated in the pathogenesis of a number of clinical disorders in patients with chronic renal failure on long-term intermittent hemodialysis treatment. The predominant disorders have been those involving either bone (osteomalacic dialysis osteodystrophy) or brain (dialysis encephalopathy). In nonuremic patients, an increased brain aluminum concentration has been implicated as a neurotoxic agent in the pathogenesis of Alzheimer's disease and was associated with experimental neurofibrillary degeneration in animals. The brain aluminum concentrations of patients dying with the syndrome of dialysis encephalopathy (dialysis dementia) are significantly higher than in dialyzed patients without the syndrome and in nondialyzed patients. Two potential sources for the increased tissue content of aluminum in patients on hemodialysis have been proposed: (1) intestinal absorption from aluminum containing phosphate-binding gels, and (2) transfer across the dialysis membrane from aluminum in the water used to prepare the dialysate. These findings, coupled with our everyday exposure to the ubiquitous occurrence of aluminum in nature, have created concerns over the potential toxicity of this metal.

  8. Apical Extrusion of Debris and Irrigants Using Different Irrigation Needles.

    PubMed

    Silva, Paula Barcellos; Krolow, Angélica Mohnsam; Pilownic, Katerine Jahnecke; Casarin, Renata Picanço; Lima, Regina Karla Pontes; Leonardo, Renato de Toledo; Pappen, Fernanda Geraldo

    2016-04-01

    This study evaluated the influence of irrigation tip, root canal curvature and final apical diameter on periapical debris and irrigant extrusion during root canal instrumentation. After being classified as mildly or moderately curved, the mesiobuccal root canals of 90 human molars were instrumented. The teeth were allocated into three groups according to the used needle type: a flat open-end needle (Group 1), a side-vented needle (Group 2) or a double side-vented needle (Group 3). The amount of extruded material after instrumentation was calculated for each group. The differences in irrigant and debris extrusion between the experimental groups were analyzed with the Mann-Whitney U test. Irrigation tips and final instrument diameter differences were analyzed with the Kruskal-Wallis test. Multiple groups were compared using the Mann-Whitney U-test with a Bonferroni correction at α=0.05. The amount of extruded material from the double side-vented needle was significantly less than the open-ended flat needle (p=0.008), but there was no difference compared to the side-vented needle (p=0.929). The results showed no effect of root curvature and final apical diameter on the amount of irrigant and debris extrusion (p>0.05). The double side-vented needles generated the least material extrusion to the periapical tissues. Irrigation needle type had the greatest influence on periapical irrigant and debris extrusion and the double side-vented needles may be safely used during endodontic therapy. PMID:27058383

  9. Equal Channel Angular Extrusion Progress Report for March 1998 - May 1999

    SciTech Connect

    Macheret, Yevgeny; Watkins, Arthur Deloss; Korth, Gary Elvan; Lillo, Thomas Martin; Flinn, John Elwood Jr.; Herling, D. R.; Smith, M. T.; Schwarz, R. B.

    1999-10-01

    Pure copper and Alloy 5083 aluminum were processed by equal channel angular extrusion (ECAE); their microstructural evolution and corresponding mechanical properties were investigated. Work also began on the possible use of ECAE to synthesize advanced materials or to consolidate metal powders or powder mixtures. The die tooling used for ECAE is described and selected microstructural and mechanical property results for ECAE-processed copper and cold-rolled (conventionally-processed) copper in the as-processed and annealed condition are compared. Results thus far show that the “pure” metal is prone to low temperature recrystallization after large strain hardening—more beneficial effects are expected in the dispersion-strengthened and precipitation-hardening alloys. The large range of tensile properties and grain sizes from the copper allowed a flow stress analysis to be performed. From this analysis, a new model for flow stress behavior is proposed. An evaluation of ECAE processing of material for spot welding electrodes began. Results to date include electrodes of ECAE-processed commercially pure copper (Alloy 101). Future work involving Glidcop® (Al2O3 oxide dispersionstrengthened copper) and CuCrZr (Cr-Zr precipitation dispersion) materials will be required to fully investigate the benefits of ECAE for electrode life extension. Initial work on Aluminum Alloy 5083 showed that ECAE led to grain refinement as well as broke up and more uniformly dispersed the hardening precipitates. This is desirable for enhancing superplastic behavior. Study of ECAE for consolidating metal powder began. Early results with a Cu-Ag powder indicate that near 100% density was achieved with room temperature consolidation.

  10. Purifying Aluminum by Vacuum Distillation

    NASA Technical Reports Server (NTRS)

    Du Fresne, E. R.

    1985-01-01

    Proposed method for purifying aluminum employs one-step vacuum distillation. Raw material for process impure aluminum produced in electrolysis of aluminum ore. Impure metal melted in vacuum. Since aluminum has much higher vapor pressure than other constituents, boils off and condenses on nearby cold surfaces in proportions much greater than those of other constituents.

  11. Study of extrusion behaviour and porridge making characteristics of wheat and guava blends.

    PubMed

    Gandhi, Neeraj; Singh, Baljit

    2015-05-01

    Extrusion cooking studies were carried out with a view to develop an instant porridge from wheat grits and guava pulp at different levels from 10 to 50 %. The mixtures were dried to bring down the moisture content to 12, 15 or 18 % and processed using twin screw extruder. The properties of extrudates (expansion ratio and density) and porridge (water absorption index, water solubility index and sensory quality) were studied. Increase in feed moisture content and guava pulp level resulted in the decrease in expansion ratio and increase in density of the extrudates. Water absorption index (WAI) increased and water solubility index (WSI) decreased with increase in feed moisture content. With increase in level of pulp, WAI decreased and WSI increased. Highly acceptable porridge was obtained at 15 % feed moisture content and 20 and 30 % guava pulp. To the samples with selected feed moisture and pulp levels, sugar was added at 20, 25 and 30 % levels to prepare the final product. Sugar level of 30 % was found out to be most acceptable. Fruit porridge stored in LDPE and aluminum laminate pouches at ambient temperature remained acceptable upto 6 months. PMID:25892805

  12. Advances in aluminum anodizing

    NASA Technical Reports Server (NTRS)

    Dale, K. H.

    1969-01-01

    White anodize is applied to aluminum alloy surfaces by specific surface preparation, anodizing, pigmentation, and sealing techniques. The development techniques resulted in alloys, which are used in space vehicles, with good reflectance values and excellent corrosive resistance.

  13. Walnut Hulls Clean Aluminum

    NASA Technical Reports Server (NTRS)

    Colberg, W. R.; Gordon, G. H.; Jackson, C. H.

    1984-01-01

    Hulls inflict minimal substrate damage. Walnut hulls found to be best abrasive for cleaning aluminum surfaces prior to painting. Samples blasted with walnut hulls showed no compressive stress of surface.

  14. Corrosion Inhibitors for Aluminum.

    ERIC Educational Resources Information Center

    Muller, Bodo

    1995-01-01

    Describes a simple and reliable test method used to investigate the corrosion-inhibiting effects of various chelating agents on aluminum pigments in aqueous alkaline media. The experiments that are presented require no complicated or expensive electronic equipment. (DDR)

  15. CORROSION PROTECTION OF ALUMINUM

    DOEpatents

    Dalrymple, R.S.; Nelson, W.B.

    1963-07-01

    Treatment of aluminum-base metal surfaces in an autoclave with an aqueous chromic acid solution of 0.5 to 3% by weight and of pH below 2 for 20 to 50 hrs at 160 to 180 deg C produces an extremely corrosion-resistant aluminum oxidechromium film on the surface. A chromic acid concentration of 1 to 2% and a pH of about 1 are preferred. (D.C.W.)

  16. Corrosion Protection of Aluminum

    DOEpatents

    Dalrymple, R. S.; Nelson, W. B.

    1963-07-01

    Treatment of aluminum-base metal surfaces in an autoclave with an aqueous chromic acid solution of 0.5 to 3% by weight and of pH below 2 for 20 to 50 hrs at 160 to 180 deg C produces an extremely corrosion-resistant aluminum oxidechromium film on the surface. A chromic acid concentration of 1 to 2% and a pH of about 1 are preferred.

  17. Light weight aluminum optics

    NASA Astrophysics Data System (ADS)

    Catura, R. C.; Vieira, J. R.

    1985-09-01

    Light weight mirror blanks were fabricated by dip-brazing a core of low mass aluminum foam material to thin face sheets of solid aluminum. The blanks weigh 40% of an equivalent size solid mirror and were diamond turned to provide reflective surfaces. Optical interferometry was used to assess their dimensional stability over 7 months. No changes in flatness are observed (to the sensitivity of the measurements of a half wavelength of red light).

  18. Exposure to chemical additives from polyvinyl chloride polymer extrusion processing

    SciTech Connect

    Lamb, C.S.

    1989-12-01

    The report presents a model to predict worker inhalation exposure due to off-gassing of additives during polyvinyl chloride (PVC) extrusion processing. Data on off-gassing of additives were reviewed in the literature, the off-gassing at normal PVC processing temperatures was studied in the laboratory, process variables were estimated from an equipment manufacturer survey, and worker-activities and possible exposure sources were observed in an industrial survey. The purpose of the study was to develop a theoretical model to predict worker inhalation exposure to additives used during PVC extrusion processing. A model to estimate the generation rate of the additive from the polymer extrudate was derived from the mass transport equations governing diffusion. The mass flow rate, initial additive volatile weight fraction, off-gassing time, diffusivity, and slab thickness are required to determine the generation rate from the model.

  19. Extrusion process optimization for toughness in balloon films

    NASA Technical Reports Server (NTRS)

    Cantor, K. M.; Harrison, I. R.

    1993-01-01

    An experimental optimization process for blown film extrusion is described and examined in terms of the effects of the technique on the toughness of balloon films. The optimization technique by Cantor (1990) is employed which involves the identification of key process variables including screw speed, nip speed, bubble diameter, and frost-line height for analysis to optimize the merit function. The procedure is employed in the extrusion of a low-density polyethylene polymer, and the resulting optimized materials are toughness- and puncture-tested. Balloon toughness is optimized in the analytical relationship, and the process parameters are modified to attain optimal toughness. The film produced is shown to have an average toughness of 24.5 MPa which is a good value for this key property of balloon materials for high-altitude flights.

  20. Compaction and segregation of sister chromatids via active loop extrusion

    PubMed Central

    Goloborodko, Anton; Imakaev, Maxim V; Marko, John F; Mirny, Leonid

    2016-01-01

    The mechanism by which chromatids and chromosomes are segregated during mitosis and meiosis is a major puzzle of biology and biophysics. Using polymer simulations of chromosome dynamics, we show that a single mechanism of loop extrusion by condensins can robustly compact, segregate and disentangle chromosomes, arriving at individualized chromatids with morphology observed in vivo. Our model resolves the paradox of topological simplification concomitant with chromosome 'condensation', and explains how enzymes a few nanometers in size are able to control chromosome geometry and topology at micron length scales. We suggest that loop extrusion is a universal mechanism of genome folding that mediates functional interactions during interphase and compacts chromosomes during mitosis. DOI: http://dx.doi.org/10.7554/eLife.14864.001 PMID:27192037

  1. Deuterium fiber extrusion and handling system for neutron production experiment

    NASA Astrophysics Data System (ADS)

    Ruden, Edward L.; Gale, Donald G.; Rahman, Hafiz U.

    2001-10-01

    A frozen D2 fiber fragment extrusion and handling system has been developed at AFRL to provide a central target for a wire array implosion on SNL's Z machine. The system, though, can be modified for use in Magnetized Target Fusion research. As presently configured, it extrudes a 0.5 mm diameter fiber, cuts the fiber to a length of 7 cm, and drops the fiber fragment into an LN2 refrigerated support structure where the fiber remains intact for about 7 minutes. A heavy hydraulically actuated blast shutter protects the extrusion system after the fragment is dropped. Design and performance information, including detailed images of the fiber during the various phases of operation, will be provided.

  2. Hot-melt extrusion of sugar-starch-pellets.

    PubMed

    Yeung, Chi-Wah; Rein, Hubert

    2015-09-30

    Sugar-starch-pellets (syn. sugar spheres) are usually manufactured through fluidized bed granulation or wet extrusion techniques. This paper introduces hot-melt extrusion (HME) as an alternative method to manufacture sugar-starch-pellets. A twin-screw extruder coupled with a Leistritz Micro Pelletizer (LMP) cutting machine was utilized for the extrusion of different types (normal-, waxy-, and high-amlyose) of corn starch, blended with varying amounts of sucrose. Pellets were characterized for their physicochemical properties including crystallinity, particle size distribution, tensile strength, and swelling expansion. Furthermore, the influence of sugar content and humidity on the product was investigated. Both sucrose and water lowered the Tg of the starch system allowing a convenient extrusion process. Mechanical strength and swelling behavior could be associated with varying amylose and amylopectin. X-ray powder diffractometric (XRPD) peaks of increasing sucrose contents appeared above 30%. This signified the oversaturation of the extruded starch matrix system with sucrose. Otherwise, had the dissolved sucrose been embedded into the molten starch matrix, no crystalline peak could have been recognized. The replacement of starch with sucrose reduced the starch pellets' swelling effect, which resulted in less sectional expansion (SEI) and changed the surface appearance. Further, a nearly equal tensile strength could be detected for sugar spheres with more than 40% sucrose. This observation stands in good relation with the analyzed values of the commercial pellets. Both techniques (fluidized bed and HME) allowed a high yield of spherical pellets (less friability) for further layering processes. Thermal influence on the sugar-starch system is still an obstacle to be controlled. PMID:26248144

  3. Formation of chromosomal domains in interphase by loop extrusion

    NASA Astrophysics Data System (ADS)

    Fudenberg, Geoffrey

    While genomes are often considered as one-dimensional sequences, interphase chromosomes are organized in three dimensions with an essential role for regulating gene expression. Recent studies have shown that Topologically Associating Domains (TADs) are fundamental structural and functional building blocks of human interphase chromosomes. Despite observations that architectural proteins, including CTCF, demarcate and maintain the borders of TADs, the mechanisms underlying TAD formation remain unknown. Here we propose that loop extrusion underlies the formation TADs. In this process, cis-acting loop-extruding factors, likely cohesins, form progressively larger loops, but stall at TAD boundaries due to interactions with boundary proteins, including CTCF. This process dynamically forms loops of various sizes within but not between TADs. Using polymer simulations, we find that loop extrusion can produce TADs as determined by our analyses of the highest-resolution experimental data. Moreover, we find that loop extrusion can explain many diverse experimental observations, including: the preferential orientation of CTCF motifs and enrichments of architectural proteins at TAD boundaries; TAD boundary deletion experiments; and experiments with knockdown or depletion of CTCF, cohesin, and cohesin-loading factors. Together, the emerging picture from our work is that TADs are formed by rapidly associating, growing, and dissociating loops, presenting a clear framework for understanding interphase chromosomal organization.

  4. The dynamics of extrusion tectonics: Insights from numerical modeling

    NASA Astrophysics Data System (ADS)

    Capitanio, Fabio A.

    2014-12-01

    To elucidate the dynamics of extrusion tectonics, I investigate the relation between subduction processes and intraplate deformation. Three-dimensional numerical models of subducting upper plate systems show that subduction of a heterogeneous buoyancy slab, that is, hosting continental and oceanic lithosphere, causes the retreat of the oceanic trench and the localization of deformation in the back arc. Similar trench evolution is found when the subducting slab partially detaches from the impinging continent; however, deformation in the upper plate interiors widens, with indentation, plastic yielding and rotation of a large block extruding laterally toward the retreating margin. Indentation stresses are consequence of the partial slab breakoff at depth and vanish when the detached slablet reaches the mantle transition zone, resulting in transient extrusion tectonics. The distance to which indentation deformation propagates depends on the ability of subducting lithosphere to propagate stress laterally and is linear with the lithospheric strength. While in the stretching back arc the plate deformation and the underlying mantle flow are coupled, they are uncoupled in the extrusion tectonics, where mostly stresses propagated through the margin drive rotations. The potential role of these diverse subduction processes in the eastern Mediterranean is discussed, suggesting that different mechanisms likely drive the tectonics of this area.

  5. Bioavailability of starch based hot stage extrusion formulations.

    PubMed

    Henrist, D; Lefebvre, R A; Remon, J P

    1999-10-01

    The aim of the study was to develop a starch based hot stage extrusion formulation for controlled drug delivery and to evaluate its in vivo behavior. The extrusion mixture consisted of 53% corn starch as the matrix forming agent, 15% sorbitol as a plasticizer, 30% theophylline monohydrate as the model drug and 2% glyceryl monostearate as a lubricant. The extrudates were produced by means of a corotating twin screw extruder of APV Baker equipped with a twin screw powder feeder and a 3-mm cylindrical die. During extrusion 20% water (based on the wet mass) was added to the powder mixture. The extrudates were dried in an oven at 60 degrees C during 48 h, cut and filled out in hard gelatine capsules, in a way that the content of two capsules corresponded with a dose of 300 mg anhydrous theophylline. The dissolution profile of the experimental dosage form was retarded with a drug release of around 80% in 8 h. The in vivo behavior of the experimental formulation was evaluated in a randomized crossover design study (n=8) with a commercially available multiple unit sustained release product as the reference formulation. The plasma samples were analyzed by a validated HPLC-UV method with solid phase extraction for the sample preparation. It was clear that the experimental formulation exhibited sustained release behavior, but that it performed less well than the multiple unit dosage form. PMID:10502624

  6. Topological Optimization of Beam Cross Section by Employing Extrusion Constraint

    NASA Astrophysics Data System (ADS)

    Zuberi, Rehan H.; Zhengxing, Zuo; Kai, Long

    2010-05-01

    Optimal cross-section design of beams plays a characteristic role which signifies the rigidity of the member in bending, shear and torsion load conditions. Practically modern overhead crane girders, railway bridge girders or rail tracks etc. require constant cross-section along the axial direction. Conventional topological optimization modeling procedures in such cases prove inadequate for the reason that these procedures generate non-uniform topologies along the axis of the bending member. To examine optimal topology of those structural bending members which commonly possess constant cross-section along the axis the topology optimization with extrusion constraint is more appropriate. The extrusion constraint method suggests a fresh approach to investigate optimal topologies of beam cross-section under the influence of realistic loading condition across the section at the beginning of design cycle. Presented study is focused upon the influence of various configuration and location of the load and boundary conditions on the topology of the of the beam cross-section which was not possible prior to the materialization of the extrusion or stamping constraint method. Several realistic loads and boundary conditions have been applied on the 3D beam model and optimal cross-section topologies obtained have uniform compliance history and convergent solutions. The lowest compliance criteria have been suggested to choose topologies as furthers shape and size optimization candidates during beam design process.

  7. Recent Developments in Mechanochemical Materials Synthesis by Extrusion.

    PubMed

    Crawford, Deborah E; Casaban, José

    2016-07-01

    Mechanochemical synthesis, i.e., reactions conducted by grinding solid reactants together with no or minimal solvent, has been demonstrated as an excellent technique for the formation of both organic and inorganic compounds. Mechanochemistry is viewed as an alternative approach to chemical synthesis and is not always considered when developing manufacturing processes of fine chemicals. Here, recent advances are highlighted regarding mechanochemical synthesis, by utilizing a well-developed continuous technique - extrusion, and the advantages it offers to further support its use in the manufacturing of these chemicals. To put this work into context, it is shown how extrusion plays a vital role for manufacturing in the food, polymer, and pharmaceutical industries, and how the research carried out by these respective industrialists provides great insight and understanding of the technique, with the results being applicable in the chemical industry. The synthesis of metal-organic frameworks (MOFs) is highlighted herein as an excellent example showcasing the advantages that extrusion provides to the manufacture of these materials, one advantage being the exceptional space time yields (STYs) reported for these processes, at three orders of magnitude greater than conventional (solvothermal) synthesis. PMID:26932541

  8. Propulsion at low Reynolds number via beam extrusion

    NASA Astrophysics Data System (ADS)

    Gosselin, Frederick; Neetzow, Paul

    2014-03-01

    We present experimental and theoretical results on the extrusion of a slender beam in a viscous fluid. We are particularly interested in the force necessary to extrude the beam as it buckles with large amplitude due to viscous friction. The problem is inspired by the propulsion of Paramecium via trichocyst extrusion. Self-propulsion in micro-organisms is mostly achieved through the beating of flagella or cilia. However, to avoid a severe aggression, unicellular Paramecium has been observed to extrude trichocysts in the direction of the aggression to burst away. These trichocysts are rod-like organelles which, upon activation, grow to about 40 μm in length in 3 milliseconds before detaching from the animal. The drag force created by these extruding rods pushing against the viscous fluid generates thrust in the opposite direction. We developed an experimental setup to measure the force required to push a steel piano wire into an aquarium filled with corn syrup. This setup offers a near-zero Reynolds number, and allows studying deployments for a range of constant extrusion speeds. The experimental results are reproduced with a numerical model coupling a large amplitude Euler-Bernoulli beam theory with a fluid load model proportional to the local beam velocity. This study was funded in part by the The Natural Sciences and Engineering Research Council of Canada.

  9. How subaerial salt extrusions influence water quality in adjacent aquifers

    NASA Astrophysics Data System (ADS)

    Mehdizadeh, Razieh; Zarei, Mehdi; Raeisi, Ezzat

    2015-12-01

    Brines supplied from salt extrusions cause significant groundwater salinization in arid and semi-arid regions where salt rock is exposed to dissolution by episodic rainfalls. Here we focus on 62 of the 122 diapirs of Hormuz salt emergent in the southern Iran. To consider managing the degradation effect that salt extrusions have on the quality of adjoining aquifers, it is first necessary to understand how they influence adjacent water resources. We evaluate here the impacts that these diapirs have on adjacent aquifers based on investigating their geomorphologies, geologies, hydrologies and hydrogeologies. The results indicate that 28/62 (45%) of our sample of salt diapirs have no significant impact on the quality of groundwater in adjoining aquifers (namely Type N), while the remaining 34/62 (55%) degrade nearby groundwater quality. We offer simple conceptual models that account for how brines flowing from each of these types of salt extrusions contaminate adjacent aquifers. We identify three main mechanisms that lead to contamination: surface impact (Type A), subsurface intrusion (Type B) and indirect infiltration (Type C). A combination of all these mechanisms degrades the water quality in nearby aquifers in 19/62 (31%) of the salt diapirs studied. Having characterized the mechanism(s) by which each diapir affects the adjacent aquifer, we suggest a few possible remediation strategies to be considered. For instance, engineering the surface runoff of diapirs Types A and C into nearby evaporation basins would improve groundwater quality.

  10. Hot-melt extrusion technology and pharmaceutical application.

    PubMed

    Wilson, Matthew; Williams, Marcia A; Jones, David S; Andrews, Gavin P

    2012-06-01

    The use of hot-melt extrusion (HME) within the pharmaceutical industry is steadily increasing, due to its proven ability to efficiently manufacture novel products. The process has been utilized readily in the plastics industry for over a century and has been used to manufacture medical devices for several decades. The development of novel drugs with poor solubility and bioavailability brought the application of HME into the realm of drug-delivery systems. This has specifically been shown in the development of drug-delivery systems of both solid dosage forms and transdermal patches. HME involves the application of heat, pressure and agitation through an extrusion channel to mix materials together, and subsequently forcing them out through a die. Twin-screw extruders are most popular in solid dosage form development as it imparts both dispersive and distributive mixing. It blends materials while also imparting high shear to break-up particles and disperse them. HME extrusion has been shown to molecularly disperse poorly soluble drugs in a polymer carrier, increasing dissolution rates and bioavailability. The most common difficulty encountered in producing such dispersions is stabilization of amorphous drugs, which prevents them from recrystallization during storage. Pharmaceutical industrial suppliers, of both materials and equipment, have increased their development of equipment and chemicals for specific use with HME. Clearly, HME has been identified as an important and significant process to further enhance drug solubility and solid-dispersion production. PMID:22838073

  11. Extrusion of metal oxide superconducting wire, tube or ribbon

    DOEpatents

    Dusek, Joseph T.

    1993-01-01

    A process for extruding a superconducting metal oxide composition YBa.sub.2 Cu.sub.3 O.sub.7-x provides a wire (tube or ribbon) having a cohesive mass and a degree of flexibility together with enhanced electrical properties. Wire diameters in the range of 6-85 mils have been produced with smaller wires on the order of 10 mils in diameter exhibiting enhanced flexibility for forming braided, or multistrand, configurations for greater current carrying capacity. The composition for extrusion contains a polymeric binder to provide a cohesive mass to bind the particles together during the extrusion process with the binder subsequently removed at lower temperatures during sintering. The composition for extrusion further includes a deflocculent, an organic plasticizer and a solvent which also are subsequently removed during sintering. Electrically conductive tubing with an inner diameter of 52 mil and an outer diameter of 87-355 mil has also been produced. Flat ribbons have been produced in the range of 10-125 mil thick by 100-500 mil wide. The superconducting wire, tube or ribbon may include an outer ceramic insulating sheath co-extruded with the wire, tubing or ribbon.

  12. Extrusion of metal oxide superconducting wire, tube or ribbon

    DOEpatents

    Dusek, Joseph T.

    1993-10-05

    A process for extruding a superconducting metal oxide composition YBa.sub.2 Cu.sub.3 O.sub.7-x provides a wire (tube or ribbon) having a cohesive mass and a degree of flexibility together with enhanced electrical properties. Wire diameters in the range of 6-85 mils have been produced with smaller wires on the order of 10 mils in diameter exhibiting enhanced flexibility for forming braided, or multistrand, configurations for greater current carrying capacity. The composition for extrusion contains a polymeric binder to provide a cohesive mass to bind the particles together during the extrusion process with the binder subsequently removed at lower temperatures during sintering. The composition for extrusion further includes a deflocculent, an organic plasticizer and a solvent which also are subsequently removed during sintering. Electrically conductive tubing with an inner diameter of 52 mil and an outer diameter of 87-355 mil has also been produced. Flat ribbons have been produced in the range of 10-125 mil thick by 100-500 mil wide. The superconducting wire, tube or ribbon may include an outer ceramic insulating sheath co-extruded with the wire, tubing or ribbon.

  13. Co-Extrusion Instabilities Modeled with a Single Fluid

    NASA Astrophysics Data System (ADS)

    Reis, T.; Sahin, M.; Wilson, H.

    2008-07-01

    Industrial processes involving co-extrusion of multiple fluids to produce multi-layered products are rife with instabilities. We consider a simple indicative instance of co-extrusion, in which there is only a single fluid involved in the flow, but two different channel branches impose differing flow histories on it. The channels merge and, ideally, a smooth film is extruded with two layers having different stress histories. In experimental studies a wavelike instability is observed with a well defined wavelength in the flow direction and a `zig-zag' like structure, indicating that the extra flow caused by the instability is three-dimensional. Suggested mechanisms for instabilities in co-extrusion include a jump in viscosity and/or first normal stress difference across a flat interface, and a coupling of normal stresses with streamline curvature in the region where the two streams merge. Using a numerical linear stability tool we investigate this instability (using a single mode fluid model throughout) and explore which of the known mechanisms is the most likely culprit here.

  14. Precipitation during infiltration of A201 aluminum alloy into Al-Fe-V-Si preform

    SciTech Connect

    Yang, C.C.; Chen, Y.C.; Chang, E.

    1996-04-01

    The newly developed Al-Fe-V-Si aluminum alloy, produced by melt spinning into ribbons, comminution of ribbon to particles, and then consolidation of particles by extrusion and forging, is being considered for high temperature applications due to the material`s characteristics of high elevated temperature strength, low density, good toughness and thermal stability. In order to extend the near-net shaping capability of the material, the authors have proposed a new process that Al-Fe-V-Si aluminum alloy particles can be consolidated by casting, in which the liquid aluminum alloy was infiltrated around the Al-Fe-V-Si particles to form a FVS1212/A201 composite material. Preliminary study of the Al-Fe-V-Si particle reinforced A201 aluminum alloy composite demonstrated that the compression strength at 300 C can be twice as high as A201 aluminum alloy. This work constitutes a continuation of the previous efforts to understand the microstructural evolution sequences, particularly the precipitation events during infiltration of the liquid aluminum into Al-Fe-V-Si preform.

  15. Aluminum, parathyroid hormone, and osteomalacia

    SciTech Connect

    Burnatowska-Hledin, M.A.; Kaiser, L.; Mayor, G.H.

    1983-01-01

    Aluminum exposure in man is unavoidable. The occurrence of dialysis dementia, vitamin D-resistant osteomalacia, and hypochromic microcytic anemia in dialysis patients underscores the potential for aluminum toxicity. Although exposure via dialysate and hyperalimentation leads to significant tissue aluminum accumulation, the ubiquitous occurrence of aluminum and the severe pathology associated with large aluminum burdens suggest that smaller exposures via the gastrointestinal tract and lungs could represent an important, though largely unrecognized, public health problem. It is clear that some aluminum absorption occurs with the ingestion of small amounts of aluminum in the diet and medicines, and even greater aluminum absorption is seen in individuals consuming large amounts of aluminum present in antacids. Aluminum absorption is enhanced in the presence of elevated circulating parathyroid hormone. In addition, elevated PTH leads to the preferential deposition of aluminum in brain and bone. Consequently, PTH is likely to be involved in the pathogenesis of toxicities in those organs. PTH excess also seems to lead to the deposition of aluminum in the parathyroid gland. The in vitro demonstration that aluminum inhibits parathyroid hormone release is consistent with the findings of a euparathyroid state in dialysis patients with aluminum related vitamin D-resistant osteomalacia. Nevertheless, it seems likely that hyperparathyroidism is at least initially involved in the pathogenesis of aluminum neurotoxicity and osteomalacia; the increases in tissue aluminum stores are followed by suppression of parathyroid hormone release, which is required for the evolution of osteomalacia. Impaired renal function is not a prerequisite for increased tissue aluminum burdens, nor for aluminum-related organ toxicity. Consequently, it is likely that these diseases will be observed in populations other than those with chronic renal disease.

  16. ALUMINUM RECLAMATION BY ACIDIC EXTRACTION OF ALUMINUM-ANODIZING SLUDGES

    EPA Science Inventory

    Extraction of aluminum-anodizing sludges with sulfuric acid was examined to determine the potential for production of commercial-strength solutions of aluminum sulfate, that is liquid alum. The research established kinetic and stoichiometric relationships and evaluates product qu...

  17. Aluminum for plasmonics.

    PubMed

    Knight, Mark W; King, Nicholas S; Liu, Lifei; Everitt, Henry O; Nordlander, Peter; Halas, Naomi J

    2014-01-28

    Unlike silver and gold, aluminum has material properties that enable strong plasmon resonances spanning much of the visible region of the spectrum and into the ultraviolet. This extended response, combined with its natural abundance, low cost, and amenability to manufacturing processes, makes aluminum a highly promising material for commercial applications. Fabricating Al-based nanostructures whose optical properties correspond with theoretical predictions, however, can be a challenge. In this work, the Al plasmon resonance is observed to be remarkably sensitive to the presence of oxide within the metal. For Al nanodisks, we observe that the energy of the plasmon resonance is determined by, and serves as an optical reporter of, the percentage of oxide present within the Al. This understanding paves the way toward the use of aluminum as a low-cost plasmonic material with properties and potential applications similar to those of the coinage metals. PMID:24274662

  18. Effects of process parameters on microstructural evolution and properties of AZ61 alloy during hot extrusion

    NASA Astrophysics Data System (ADS)

    Lu, Y. L.; Li, X. C.; Xu, W. T.; Wu, D.; Yang, M.

    2015-12-01

    Extrusion testing of AZ61 alloys were conducted at deformation temperatures of 300°C to 410°C and extrusion ratios of 3, 10 and 16 respectively to optimize the process parameters. The experimental results show that deformation process parameters significantly affect microstructures and properties. Optical microscope observation shows that grains are refined greatly during hot extrusion and the mechanical properties are improved with increasing the extrusion ratio. For AZ61 alloy, the optimal extrusion temperature is 370 °C. When deformation temperature increases, more slip systems participate in the plastic deformation, which leads to the decrease of the cleavage surface. After severe plastic deformation, a remarkable improvement of ductility of AZ61 alloy has been found. The ductile fracture mechanism is gradually dominant instead of brittle fracture with increasing the extrusion ratio.

  19. Regeneration of aluminum hydride

    DOEpatents

    Graetz, Jason Allan; Reilly, James J; Wegrzyn, James E

    2012-09-18

    The present invention provides methods and materials for the formation of hydrogen storage alanes, AlH.sub.x, where x is greater than 0 and less than or equal to 6 at reduced H.sub.2 pressures and temperatures. The methods rely upon reduction of the change in free energy of the reaction between aluminum and molecular H.sub.2. The change in free energy is reduced by lowering the entropy change during the reaction by providing aluminum in a state of high entropy, and by increasing the magnitude of the change in enthalpy of the reaction or combinations thereof.

  20. Regeneration of aluminum hydride

    DOEpatents

    Graetz, Jason Allan; Reilly, James J.

    2009-04-21

    The present invention provides methods and materials for the formation of hydrogen storage alanes, AlH.sub.x, where x is greater than 0 and less than or equal to 6 at reduced H.sub.2 pressures and temperatures. The methods rely upon reduction of the change in free energy of the reaction between aluminum and molecular H.sub.2. The change in free energy is reduced by lowering the entropy change during the reaction by providing aluminum in a state of high entropy, by increasing the magnitude of the change in enthalpy of the reaction or combinations thereof.

  1. Elevated temperature aluminum alloys

    NASA Technical Reports Server (NTRS)

    Meschter, Peter (Inventor); Lederich, Richard J. (Inventor); O'Neal, James E. (Inventor)

    1989-01-01

    Three aluminum-lithium alloys are provided for high performance aircraft structures and engines. All three alloys contain 3 wt % copper, 2 wt % lithium, 1 wt % magnesium, and 0.2 wt % zirconium. Alloy 1 has no further alloying elements. Alloy 2 has the addition of 1 wt % iron and 1 wt % nickel. Alloy 3 has the addition of 1.6 wt % chromium to the shared alloy composition of the three alloys. The balance of the three alloys, except for incidentql impurities, is aluminum. These alloys have low densities and improved strengths at temperatures up to 260.degree. C. for long periods of time.

  2. Aluminum Hydroxide and Magnesium Hydroxide

    MedlinePlus

    Aluminum Hydroxide, Magnesium Hydroxide are antacids used together to relieve heartburn, acid indigestion, and upset stomach. They ... They combine with stomach acid and neutralize it. Aluminum Hydroxide, Magnesium Hydroxide are available without a prescription. ...

  3. Hot extruded carbon nanotube reinforced aluminum matrix composite materials

    NASA Astrophysics Data System (ADS)

    Kwon, Hansang; Leparoux, Marc

    2012-10-01

    Carbon nanotube (CNT) reinforced aluminum (Al) matrix composite materials were successfully fabricated by mechanical ball milling followed by powder hot extrusion processes. Microstructural analysis revealed that the CNTs were well dispersed at the boundaries and were aligned with the extrusion direction in the composites obtained. Although only a small quantity of CNTs were added to the composite (1 vol%), the Vickers hardness and the tensile strength were significantly enhanced, with an up to three-fold increase relative to that of pure Al. From the fractography of the extruded Al-CNT composite, several shapes were observed in the fracture surface, and this unique morphology is discussed based on the strengthening mechanism. The damage in the CNTs was investigated with Raman spectroscopy. However, the Al-CNT composite materials were not only strengthened by the addition of CNTs but also enhanced by several synergistic effects. The nanoindentation stress-strain curve was successfully constructed by setting the effective zero-load and zero-displacement points and was compared with the tensile stress-strain curve. The yield strengths of the Al-CNT composites from the nanoindentation and tensile tests were compared and discussed. We believe that the yield strength can be predicted using a simple nanoindentation stress/strain curve and that this method will be useful for materials that are difficult to machine, such as complex ceramics.

  4. Hot extruded carbon nanotube reinforced aluminum matrix composite materials.

    PubMed

    Kwon, Hansang; Leparoux, Marc

    2012-10-19

    Carbon nanotube (CNT) reinforced aluminum (Al) matrix composite materials were successfully fabricated by mechanical ball milling followed by powder hot extrusion processes. Microstructural analysis revealed that the CNTs were well dispersed at the boundaries and were aligned with the extrusion direction in the composites obtained. Although only a small quantity of CNTs were added to the composite (1 vol%), the Vickers hardness and the tensile strength were significantly enhanced, with an up to three-fold increase relative to that of pure Al. From the fractography of the extruded Al-CNT composite, several shapes were observed in the fracture surface, and this unique morphology is discussed based on the strengthening mechanism. The damage in the CNTs was investigated with Raman spectroscopy. However, the Al-CNT composite materials were not only strengthened by the addition of CNTs but also enhanced by several synergistic effects. The nanoindentation stress-strain curve was successfully constructed by setting the effective zero-load and zero-displacement points and was compared with the tensile stress-strain curve. The yield strengths of the Al-CNT composites from the nanoindentation and tensile tests were compared and discussed. We believe that the yield strength can be predicted using a simple nanoindentation stress/strain curve and that this method will be useful for materials that are difficult to machine, such as complex ceramics. PMID:23011263

  5. PROCESS FOR REMOVING ALUMINUM COATINGS

    DOEpatents

    Flox, J.

    1959-07-01

    A process is presented for removing aluminum jackets or cans from uranium slugs. This is accomplished by immersing the aluminum coated uranium slugs in an aqueous solution of 9 to 20% sodium hydroxide and 35 to 12% sodium nitrate to selectively dissolve the aluminum coating, the amount of solution being such as to obtain a molar ratio of sodium hydroxide to aluminum of at least

  6. FEM Modeling of Extrusion of Square Billet to Square Product Through Cosine Dies

    NASA Astrophysics Data System (ADS)

    Rout, Akshaya Kumar; Maity, Kalipada; Sahoo, Susanta Kumar

    2016-06-01

    The die profile plays an important role in reduction of extrusion load, evolution of uniform micro-structure and overall improvement of surface integrity of reproduct. In the present investigation, a numerical FEM approach has been carried out for extrusion through cosine die profile using DEFORM-3D software for steady state deformation using rigid plastic material. The extrusion load has been predicted. The comparison made with the experimental results. To show the validity and effectiveness of the result, experiments on hot extrusion were performed, and the results of computation are found to be in good agreement with those of the experiments.

  7. RECLAMATION OF ALUMINUM FINISHING SLUDGES

    EPA Science Inventory

    The research study of the reclamation of aluminum-anodizing sludges was conducted in two sequential phases focused on enhanced dewatering of aluminum-anodizing sludges to produce commercial-strength solutions of aluminum sulfate, i.e., liquid alum. The use of high-pressure (14 to...

  8. Electrically conductive anodized aluminum coatings

    NASA Technical Reports Server (NTRS)

    Alwitt, Robert S. (Inventor); Liu, Yanming (Inventor)

    2001-01-01

    A process for producing anodized aluminum with enhanced electrical conductivity, comprising anodic oxidation of aluminum alloy substrate, electrolytic deposition of a small amount of metal into the pores of the anodized aluminum, and electrolytic anodic deposition of an electrically conductive oxide, including manganese dioxide, into the pores containing the metal deposit; and the product produced by the process.

  9. Aluminum battery alloys

    DOEpatents

    Thompson, David S.; Scott, Darwin H.

    1985-01-01

    Aluminum alloys suitable for use as anode structures in electrochemical cs are disclosed. These alloys include iron levels higher than previously felt possible, due to the presence of controlled amounts of manganese, with possible additions of magnesium and controlled amounts of gallium.

  10. Mechanisms of aluminum tolerance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aluminum (Al) toxicity limits agricultural productivity over much of the world’s arable land by inhibiting root growth and development. Affected plants have difficulty in acquiring adequate water and nutrition from their soil environments and thus have stunted shoot development and diminished yield....

  11. Maize aluminum tolerance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize is one of the most economically important food crops grown on acid soils, where aluminum (Al) toxicity greatly limits crop yields. Considerable variation for Al tolerance exists in maize, and this variation has been exploited for many years by plant breeders to enhance maize Al tolerance. Curr...

  12. Aluminum-ferricyanide battery

    SciTech Connect

    Marsh, C.; Licht, S.L.

    1993-11-29

    A battery capable of producing high current densities with high charge capacity is described which includes an aluminum anode, a ferricyanide electrolyte and a second electrode capable of reducing ferricyanide electrolyte which is either dissolved in an alkaline solution or alkaline seawater solution. The performance of the battery is enhanced by high temperature and high electrolyte flow rates.

  13. Aluminum Sulfate 18 Hydrate

    ERIC Educational Resources Information Center

    Young, Jay A.

    2004-01-01

    A chemical laboratory information profile (CLIP) of the chemical, aluminum sulfate 18 hydrate, is presented. The profile lists physical and harmful properties, exposure limits, reactivity risks, and symptoms of major exposure for the benefit of teachers and students using the chemical in the laboratory.

  14. Fluxless aluminum brazing

    DOEpatents

    Werner, W.J.

    1974-01-01

    This invention relates to a fluxless brazing alloy for use in forming brazed composites made from members of aluminum and its alloys. The brazing alloy consists of 35-55% Al, 10--20% Si, 25-60% Ge; 65-88% Al, 2-20% Si, 2--18% In; 65--80% Al, 15-- 25% Si, 5- 15% Y. (0fficial Gazette)

  15. Aluminum battery alloys

    DOEpatents

    Thompson, D.S.; Scott, D.H.

    1984-09-28

    Aluminum alloys suitable for use as anode structures in electrochemical cells are disclosed. These alloys include iron levels higher than previously felt possible, due to the presence of controlled amounts of manganese, with possible additions of magnesium and controlled amounts of gallium.

  16. REMOVAL OF ALUMINUM COATINGS

    DOEpatents

    Peterson, J.H.

    1959-08-25

    A process is presented for dissolving aluminum jackets from uranium fuel elements without attack of the uranium in a boiling nitric acid-mercuric nitrate solution containing up to 50% by weight of nitrtc acid and mercuric nitrate in a concentration of between 0.05 and 1% by weight.

  17. Building an aluminum car

    SciTech Connect

    Ashley, S.

    1994-05-01

    This article examines the increasing use of aluminum in automobiles to decrease weight and consequently increase fuel economy. The topics of the article include federal fuel economy goals, the development of optimum body structure and manufacturing techniques, comparison with steel, cost of materials, weight reduction and recycling of materials.

  18. Sequential extrusion-microwave pretreatment of switchgrass and big bluestem.

    PubMed

    Karunanithy, C; Muthukumarappan, K; Gibbons, W R

    2014-02-01

    Developing an effective and economical biomass pretreatment method is a significant roadblock to meeting the ever growing demand for transportation fuels. Earlier studies with different feedstocks revealed that in the absence of chemicals, neither extrusion nor microwave could be standalone pretreatments. However, there is potential that the advantages of these individual methods can be harnessed in a sequential pretreatment process. Accordingly, switchgrass and big bluestem were extruded and then subject to microwave pretreatment, under optimal conditions that had been separately determined in prior studies. Pretreated biomass was then subject to enzymatic hydrolysis to understand the effectiveness of the sequential pretreatment on sugar recovery and generation of fermentation inhibitors. Statistical analysis confirmed that moisture content, microwave power level, and exposure time (and their interactions) had significant influence on sugar recovery. Sequential pretreatment of switchgrass (25% moisture, 450W and 2.5min) resulted in a maximum glucose, xylose, and total sugar recovery of 52.6%, 75.5%, and 59.2%, respectively. This was higher by 1.27 and 2.71, 1.21 and 4.60, and 1.25 and 2.87 times compared to extrusion alone and the unpretreated control, respectively. The same sequential pretreatment conditions achieved maximum glucose, xylose, and total sugar recovery of 83.2%, 92.1%, and 68.1%, respectively, for big bluestem. This was 1.14 and 4.1, 1.18 and 2.7, and 1.20 and 3.0 times higher than extrusion alone and the unpretreated control, respectively. This sequential pretreatment process did not aggravate acetic acid formation over levels observed with the individual pretreatments. Furthermore, furfural, HMF, and formic acid were not detected in any of the treatments. Although the sequential pretreatment process enhanced sugar recovery without increasing the levels of potential fermentation inhibitors, the increased energy input for the microwave treatment may

  19. Repetitive fracturing during spine extrusion at Unzen volcano, Japan

    NASA Astrophysics Data System (ADS)

    Lamb, O. D.; De Angelis, S.; Umakoshi, K.; Hornby, A. J.; Kendrick, J. E.; Lavallée, Y.

    2015-12-01

    Rhythmic seismicity associated with spine extrusion is a well-documented phenomenon at a number of dome-forming volcanic systems. At Unzen volcano, Japan, a 4-year dome-forming eruption concluded with the emplacement of a spine from October 1994 to February 1995, offering a valuable opportunity to further investigate seismogenic processes at dome-forming volcanoes. Using continuous data recorded at a seismic station located close to the dome, this study explores trends in the seismic activity during the extrusion of the spine. We identify a total of 12 208 volcano-seismic events in the period between October 1994 and February 1995. Hourly event counts indicate cyclic activity with periods of ∼ 40 to ∼ 100 h, attributed to pulsatory ascent defined by strain localisation and faulting at the conduit margins. Waveform correlation revealed two strong clusters (a.k.a. multiplets, families) which are attributed to fracturing along the margins of the shallow, ascending spine. Further analysis indicates variable seismic velocities during the spine extrusion as well as migration of the cluster sources along the spine margins. Our interpretation of the results from seismic data analyses is supported by previously published field and experimental observations, suggesting that the spine was extruded along an inclined conduit with brittle and ductile deformation occurring along the margins. We infer that changes in stress conditions acting on the upper and lower spine margins led to deepening and shallowing of the faulting sources, respectively. We demonstrate that the combination of geophysical, field and experimental evidence can help improve physical models of shallow conduit processes.

  20. The Limits of Extrusion in the Western Himalaya

    NASA Astrophysics Data System (ADS)

    Zhang, K.; Webb, A. G.; Donaldson, D.; Johnson, S.; Elorriaga, T.

    2014-12-01

    Himalayan orogenesis is commonly explained by 1) extrusion models, involving expulsion of high-grade rocks southwards from beneath Tibet and up towards the High Himalayan orographic front, and/or 2) duplexing models, involving accretion of thrust horses from the downgoing Indian plate to the over-riding orogenic wedge. Most extrusion models predict exhumation and erosion of upper-amphibolite facies metamorphic rocks between the Main Central thrust (MCT) and a structurally higher normal fault, and therefore can be tested by determining if such high grade rocks occur between the MCT and the Indus-Yalu suture to the north. Prior qualitative studies suggest that such rocks are missing across the east Ladakh / Chamba and Kashmir regions of the western Himalaya. Here we present new quantitative and semi-quantitative results that document low peak metamorphic temperatures along a northeast-trending transect across the east Ladakh / Chamba Himalaya. We performed illite crystallinity (IC) and quartz grain boundary analyses to determine metamorphic and deformation temperatures, respectively. Calibrated IC values of structurally high samples range from 0.25 to 0.54, indicating temperatures of ~100 ˚C to ~300 ˚C. In structurally lower, muscovite +/- biotite-bearing meta-pelitic and meta-psammitic rocks, quartz grain boundaries show bulging recrystallization fabrics, corresponding to deformation temperatures of <~450 ˚C. Local exceptions occur along the southeast margin of the study region near a dome, where quartz sub-grain rotation fabrics indicate deformation temperatures between ~450 ˚C and ~550 ˚C. Our results, combined with similar IC values to the north from Girard et al. [2001, Clay Minerals v. 36, p. 237-247], demonstrate that a continuous strip of <~450 ˚C rocks extends from the MCT to the Indus-Yalu suture here. Therefore the predictions of extrusion models are not met in this portion of the Himalaya; we present alternative duplexing models.

  1. Alkaline twin-screw extrusion pretreatment for fermentable sugar production

    PubMed Central

    2013-01-01

    Background The inevitable depletion of fossil fuels has resulted in an increasing worldwide interest in exploring alternative and sustainable energy sources. Lignocellulose, which is the most abundant biomass on earth, is widely regarded as a promising raw material to produce fuel ethanol. Pretreatment is an essential step to disrupt the recalcitrance of lignocellulosic matrix for enzymatic saccharification and bioethanol production. This paper established an ATSE (alkaline twin-screw extrusion pretreatment) process using a specially designed twin-screw extruder in the presence of alkaline solution to improve the enzymatic hydrolysis efficiency of corn stover for the production of fermentable sugars. Results The ATSE pretreatment was conducted with a biomass/liquid ratio of 1/2 (w/w) at a temperature of 99°C without heating equipment. The results indicated that ATSE pretreatment is effective in improving the enzymatic digestibility of corn stover. Sodium hydroxide loading is more influential factor affecting both sugar yield and lignin degradation than heat preservation time. After ATSE pretreatment under the proper conditions (NaOH loading of 0.06 g/g biomass during ATSE and 1 hour heat preservation after extrusion), 71% lignin removal was achieved and the conversions of glucan and xylan in the pretreated biomass can reach to 83% and 89% respectively via subsequent enzymatic hydrolysis (cellulase loading of 20 FPU/g-biomass and substrate consistency of 2%). About 78% of the original polysaccharides were converted into fermentable sugars. Conclusions With the physicochemical functions in extrusion, the ATSE method can effectively overcome the recalcitrance of lignocellulose for the production of fermentable sugars from corn stover. This process can be considered as a promising pretreatment method due to its relatively low temperature (99°C), high biomass/liquid ratio (1/2) and satisfied total sugar yield (78%), despite further study is needed for process

  2. Mesoporous aluminum phosphite

    SciTech Connect

    El Haskouri, Jamal; Perez-Cabero, Monica; Guillem, Carmen; Latorre, Julio; Beltran, Aurelio; Beltran, Daniel; Amoros, Pedro

    2009-08-15

    High surface area pure mesoporous aluminum-phosphorus oxide-based derivatives have been synthesized through an S{sup +}I{sup -} surfactant-assisted cooperative mechanism by means of a one-pot preparative procedure from aqueous solution and starting from aluminum atrane complexes and phosphoric and/or phosphorous acids. A soft chemical extraction procedure allows opening the pore system of the parent as-prepared materials by exchanging the surfactant without mesostructure collapse. The nature of the pore wall can be modulated from mesoporous aluminum phosphate (ALPO) up to total incorporation of phosphite entities (mesoporous aluminum phosphite), which results in a gradual evolution of the acidic properties of the final materials. While phosphate groups in ALPO act as network building blocks (bridging Al atoms), the phosphite entities become basically attached to the pore surface, what gives practically empty channels. The mesoporous nature of the final materials is confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and N{sub 2} adsorption-desorption isotherms. The materials present regular unimodal pore systems whose order decreases as the phosphite content increases. NMR spectroscopic results confirm the incorporation of oxo-phosphorus entities to the framework of these materials and also provide us useful information concerning the mechanism through which they are formed. - Abstract: TEM image of the mesoporous aluminum phosphite showing the hexagonal disordered pore array that is generated by using surfactant micelles as template. Also a scheme emphasizing the presence of an alumina-rich core and an ALPO-like pore surface is presented.

  3. Spontaneous cutaneous extrusion of a parotid gland sialolith.

    PubMed

    Brown, Kelly; Cheah, Tricia; Ha, Jennifer F

    2016-01-01

    Parotid gland sialolithiasis is an uncommon condition that can cause pain and recurrent infection in affected patients. Migration of a stone through a fistula is a rare but possible complication of untreated sialolithiasis. We present a case of parotid gland sialolithiasis in a 63-year-old woman with recurrent episodes of parotitis and facial pain, which resolved through spontaneous extrusion of the stone (11 mm) through a cutaneous fistula while awaiting surgery. Management is typically conservative or surgical, depending on the location and size of the stone, and the clinical presentation. PMID:27143163

  4. Hydrostatic extrusion of Cu-Ag melt spun ribbon

    SciTech Connect

    Hill, Mary Ann; Bingert, John F.; Bingert, Sherri A.; Thoma, Dan J.

    1998-01-01

    The present invention provides a method of producing high-strength and high-conductance copper and silver materials comprising the steps of combining a predetermined ratio of the copper with the silver to produce a composite material, and melt spinning the composite material to produce a ribbon of copper and silver. The ribbon of copper and silver is heated in a hydrogen atmosphere, and thereafter die pressed into a slug. The slug then is placed into a high-purity copper vessel and the vessel is sealed with an electron beam. The vessel and slug then are extruded into wire form using a cold hydrostatic extrusion process.

  5. Hydrostatic extrusion of Cu-Ag melt spun ribbon

    SciTech Connect

    Hill, M.A.; Bingert, J.F.; Bingert, S.A.; Thoma, D.J.

    1998-09-08

    The present invention provides a method of producing high-strength and high-conductance copper and silver materials comprising the steps of combining a predetermined ratio of the copper with the silver to produce a composite material, and melt spinning the composite material to produce a ribbon of copper and silver. The ribbon of copper and silver is heated in a hydrogen atmosphere, and thereafter die pressed into a slug. The slug then is placed into a high-purity copper vessel and the vessel is sealed with an electron beam. The vessel and slug then are extruded into wire form using a cold hydrostatic extrusion process. 5 figs.

  6. Multicore MgB 2 wires made by hydrostatic extrusion

    NASA Astrophysics Data System (ADS)

    Kováč, P.; Pachla, W.; Hušek, I.; Kulczyk, M.; Melišek, T.; Holúbek, T.; Diduszko, R.; Reissner, M.

    2008-12-01

    Seven-filament MgB2/Fe and MgB2/Nb/Cu wires have been made by in situ process using hydrostatic extrusion, drawing and two-axial drawing deformation into the wire size of 1.1 × 1.1 mm2. The conductors were sintered at 650 °C/0.5 h and studied in terms of field-dependent transport critical current density and thermal stability. XRD, SEM and EDX analysis were applied for structural characterization. Transport current property and compositional/structural differences are compared and discussed in connection to used powders and metallic materials.

  7. SOLDERING OF ALUMINUM BASE METALS

    DOEpatents

    Erickson, G.F.

    1958-02-25

    This patent deals with the soldering of aluminum to metals of different types, such as copper, brass, and iron. This is accomplished by heating the aluminum metal to be soldered to slightly above 30 deg C, rubbing a small amount of metallic gallium into the part of the surface to be soldered, whereby an aluminum--gallium alloy forms on the surface, and then heating the aluminum piece to the melting point of lead--tin soft solder, applying lead--tin soft solder to this alloyed surface, and combining the aluminum with the other metal to which it is to be soldered.

  8. A comparison of different irrigation systems and gravitational effect on final extrusion of the irrigant

    PubMed Central

    Görduysus, Melahat; Görduysus, Ömer

    2015-01-01

    Background The aim of this study was to compare manual needle irrigation (MNI), RinsEndo (RE), and passive ultrasonic irrigation (PUI), and assess the effect of gravity on extrusion from the apex in vitro. Material and Methods The distobuccal roots of molars were used and the canals were instrumented up to F2. Teeth were mounted on models, which permitted visualization and manipulation of the apices for necessary procedures. The models were placed in articulator to simulate the jaw. Six groups (G) were formed as: G1, G2 and G3 represented mandibular positioning of teeth and were irrigated with MNI, RE, and PUI, respectively, while G4, G5, and G6 represented maxillary positioning of teeth and were also irrigated in same sequence. Prior to the final irrigation, 72 cube-shaped foam pieces covered with aluminum foil were weighed and the values were recorded as the initial weights. The cubes were then placed on the apical part of each sample. Final irrigation was performed with distilled water and the cubes were weighed again to determine their final weight. Data were analyzed using Kruskal-Wallis and Mann-Whitney U post-hoc test (p<0.05). Results Irrespective of the irrigation technique used, the amount of irrigant extruded from the apex showed a statistically significant difference related to the effect of gravity (p<0.05). There was no statistically significant difference between irrigation methods (p>0.05). When the irrigation systems were compared to examine the effect of gravity, the significant difference was found between G2 and G5 (p<0.05). Conclusions Within the limitations of this study, MNI and PUI were found to be reliable irrigation systems. Caution should be exercised when using RinsEndo. Key words:Final irrigation, manual needle irrigation, passive ultrasonic irrigation, RinsEndo. PMID:26155336

  9. Continuous manufacturing of solid lipid nanoparticles by hot melt extrusion.

    PubMed

    Patil, Hemlata; Kulkarni, Vijay; Majumdar, Soumyajit; Repka, Michael A

    2014-08-25

    Solid lipid nanoparticles (SLN) can either be produced by hot homogenization of melted lipids at higher temperatures or by a cold homogenization process. This paper proposes and demonstrates the formulation of SLN for pharmaceutical applications by combining two processes: hot melt extrusion (HME) technology for melt-emulsification and high-pressure homogenization (HPH) for size reduction. This work aimed at developing continuous and scalable processes for SLN by mixing a lipid and aqueous phase containing an emulsifier in the extruder barrel at temperatures above the melting point of the lipid and further reducing the particle size of emulsion by HPH linked to HME in a sequence. The developed novel platform demonstrated better process control and size reduction compared to the conventional process of hot homogenization (batch process). Varying the process parameters enabled the production of SLN below 200 nm (for 60 mg/ml lipid solution at a flow rate of 100ml/min). Among the several process parameters investigated, the lipid concentration, residence time and screw design played major roles in influencing the size of the SLN. This new process demonstrates the potential use of hot melt extrusion technology for continuous and large-scale production of SLN. PMID:24853459

  10. Emulsifiers and thickeners on extrusion-cooked instant rice product.

    PubMed

    Wang, Jin Peng; An, Hong Zhou; Jin, Zheng Yu; Xie, Zheng Jun; Zhuang, Hai Ning; Kim, Jin Moon

    2013-08-01

    Extrusion-cooked instant rice was prepared by optimizing the formulation with emulsifiers, glycerol monostearate (GMS), soybean lecithin (LC), and sodiumstearoyl lactylate (SSL), and thickeners, gum Arabic (GA), sodium alginate (SA), and sticky rice (SR). The emulsifiers addition caused increase of degree of gelatinization (DG), and decrease of water soluble carbohydrate (WSC), α-amylase sensitivity, water soluble index (WAI) and adhesive for extrudates, while the thickeners addition increased extrudates DG, bulk density (BD), WSC, α-amylase sensitivity, WAI, hydration rate (HR) and adhesiveness. Based on the data generated by a single additive at various levels, optimum formulation was obtained employing orthogonal matrix system with combination of the selected additives for extrusion cooking. Extrudates were evaluated for optimum hydration time followed by drying to prepare the finished product. Texture profile analysis and sensory evaluation indicate that quality of the finished product is equivalent to that of the round shaped rice and superior to a commercial instant rice product. This study also demonstrates possibility of value-added and versatile instant rice product development using broken rice. PMID:24425967

  11. Analysis on dynamic tensile extrusion behavior of UFG OFHC Cu

    NASA Astrophysics Data System (ADS)

    Park, Kyung-Tae; Park, Leeju; Kim, Hak Jun; Kim, Seok Bong; Lee, Chong Soo

    2014-08-01

    Dynamic tensile extrusion (DTE) tests with the strain rate order of ~105 s-1 were conducted on coarse grained (CG) Cu and ultrafine grained (UFG) Cu. ECAP of 16 passes with route Bc was employed to fabricate UFG Cu. DTE tests were carried out by launching the sphere samples to the conical extrusion die at a speed of ~475 m/sec in a vacuumed gas gun system. UFG Cu was fragmented into 3 pieces and showed a DTE elongation of ~340%. CG Cu exhibited a larger DTE elongation of ~490% with fragmentation of 4 pieces. During DTE tests, dynamic recrystallization occurred in UFG Cu, but not in CG Cu. In order to examine the DTE behavior of CG Cu and UFG Cu under very high strain rates, a numerical analysis was undertaken by using a commercial finite element code (LS-DYNA 2D axis-symmetric model) with the Johnson - Cook model. The numerical analysis correctly predicted fragmentation and DTE elongation of CG Cu. But, the experimental DTE elongation of UFG Cu was much smaller than that predicted by the numerical analysis. This difference is discussed in terms of microstructural evolution of UFG Cu during DTE tests.

  12. Extrusion foaming of protein-based thermoplastic and polyethylene blends

    NASA Astrophysics Data System (ADS)

    Gavin, Chanelle; Lay, Mark C.; Verbeek, Casparus J. R.

    2016-03-01

    Currently the extrusion foamability of Novatein® Thermoplastic Protein (NTP) is being investigated at the University of Waikato in collaboration with the Biopolymer Network Ltd (NZ). NTP has been developed from bloodmeal (>86 wt% protein), a co-product of the meat industry, by adding denaturants and plasticisers (tri-ethylene glycol and water) allowing it to be extruded and injection moulded. NTP alone does not readily foam when sodium bicarbonate is used as a chemical blowing agent as its extensional viscosity is too high. The thermoplastic properties of NTP were modified by blending it with different weight fractions of linear low density polyethylene (LLDPE) and polyethylene grafted maleic anhydride (PE-g-MAH) compatibiliser. Extrusion foaming was conducted in two ways, firstly using the existing water content in the material as the blowing agent and secondly by adding sodium bicarbonate. When processed in a twin screw extruder (L/D 25 and 10 mm die) the material readily expanded due to the internal moisture content alone, with a conditioned expansion ratio of up to ± 0.13. Cell structure was non-uniform exhibiting a broad range cell sizes at various stages of formation with some coalescence. The cell size reduced through the addition of sodium bicarbonate, overall more cells were observed and the structure was more uniform, however ruptured cells were also visible on the extrudate skin. Increasing die temperature and introducing water cooling reduced cell size, but the increased die temperature resulted in surface degradation.

  13. Extrusion cooking using a twin-screw apparatus reduces toxicity of fumonisin-contaminated corn grits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extrusion cooking using a single screw configuration reduced fumonisin concentrations of corn grits in an earlier study. Adding glucose before cooking enhanced reductions and, in one of three trials, partially reversed in vivo toxicity. To determine the effectiveness of extrusion using the more effi...

  14. Prediction of samples failure during severe plastic deformation by multiple extrusion

    NASA Astrophysics Data System (ADS)

    Shibakov, V. G.; Pankratov, D. L.; Andreev, A. P.; Andreeva, S. I.

    2015-06-01

    A method of obtaining a hardened semi-intensive plastic deformation by extrusion is considered. The results of simulation process at different stages of extrusion are given. Conclusions are drawn about the applicability of the simulation results to obtain the axisymmetric products. The results of sample study are given according to the method of determining the criterion of damage Ψ.

  15. Spontaneous extrusion of staghorn renal calculus with nephrocutaneous fistula in a child.

    PubMed

    Purkait, Bimalesh; Sinha, Rahul Janak; Bansal, Ankur; Singh, Vishwajeet

    2016-01-01

    Renal stone disease may present as nephrocutaneous fistula. Spontaneous extrusion of renal stone with nephrocutaneous fistula is rare. Most of the cases have been reported in adults. We present a case of nephrocutaneous fistula with spontaneous extrusion of staghorn renal calculus in a paediatric patient. PMID:27068729

  16. Finite element simulation of extrusion of optical fiber preforms: Effects of wall slip

    NASA Astrophysics Data System (ADS)

    Zhang, Zhi Feng; Zhang, Yilei

    2016-03-01

    Extrusion has been successfully used to fabricate optical fiber preforms, especially microstructured ones. Although simplified mathematical model has been used to calculate the extrusion pressure or speed, more frequently die design and extrusion process optimization depend on trial and error, which is especially true for complex die and preform design. This paper employs the finite element method (FEM) to simulate the billet extrusion process to investigate the relationship between the extruding pressure, the billet viscosity, the wall slip condition and the extruding speed for extrusion of rod preforms. The slipping wall boundary condition is taken into account of the finite element model, and the simulated extruding pressure agrees with the one experimental value reported preciously. Then the dependence of the extruding speed on the extruding pressure, billet viscosity and the slip speed is systematically simulated. Simulated data is fitted to a second order polynomial model to describe their relationship, and the terms of the model are reduced from nine to five by using a statistical method while maintaining the fitting accuracy. The FEM simulation and the fitted model provide a convenient and dependable way to calculate the extrusion pressure, speed or other process parameters, which could be used to guide experimental design for future preform extrusion. Furthermore, the same simulation could be used to optimize die design and extrusion process to improve quality of extruded preforms.

  17. SUPERCRITICAL CO2 EXTRUSION – OPPORTUNITIES FOR FOOD AND BIOLOGICAL PROCESSING

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extrusion cooking is a high temperature, short time processing method. During extrusion processing, many chemical and structural changes of the feed materials occur inside the barrel due to high temperatures, shear rates, and pressures. These alterations affect bonding between molecules, which in...

  18. Physical properties, molecular structures and protein quality of texturized whey protein isolate: effect of extrusion temperature

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extrusion is a powerful food processing operation, which utilizes high temperature and high shear force to produce a product with unique physical and chemical characteristics. Texturization of whey protein isolate (WPI) through extrusion for the production of protein fortified snack foods has provid...

  19. Was the Himalayan crystalline core emplaced by extrusion or underplating?

    NASA Astrophysics Data System (ADS)

    He, D.; Webb, A. G.; Larson, K.; Schmitt, A. K.

    2012-12-01

    Models of Himalayan mountain-building are generally dominated by one of two end-member processes: extrusion and underplating. Extrusion requires exhumation of mid-crustal material between surface-breaching faults: a thrust fault below and a normal fault above. Underplating involves mid-crustal accretion of material from underthrusting India to the over-riding Himalayan orogen. There is a key structure in the Himalaya for differentiating the models - the South Tibet detachment (STD): is it a normal fault (consistent with extrusion) or a backthrust (consistent with underplating)? We test the underplating model by examining two regions in the Nepal Himalaya where the STD is proposed to merge with the fault system bounding the base of the crystalline core, i.e., the Main Central thrust (MCT). These study regions are along the northern margins of the Dadeldhura klippe and Kathmandu nappe. Field mapping, microstructural, quartz c-axis fabric, and geochronological studies were integrated to analyze transects across these two regions. Our structural mapping reveals top-north shear zones along the north margin of the Kathmandu Nappe (the Galchi shear zone) and along the Tila river (the Tila shear zone) on the northeast margin of the Dadeldhura klippe. Gneisses between these shear zones and MCT pinch out to the south. Asymmetric quartz c-axis fabrics indicate consistent top-north shearing in both shear zones. Quartz microstructures and opening angles of quartz c-axis fabrics indicate deformation temperatures of ~650 -350 °C from the base to the immediate hanging wall of the Tila shear zone. Zircon U-Pb dating of rims for crosscutting leucogranites yields age clusters ~30-17 Ma for the Tila shear zone and ~35-14 Ma for the Galchi shear zone. These ages constrain the motion of the two shear zones as Early to Middle Miocene. All characteristics of the two shear zones including the sense of shear, structural position, thermal profile, and timing of motion are consistent with

  20. Aluminum permanganate battery

    SciTech Connect

    Marsh, C.; Licht, S.L.

    1993-11-30

    A battery is provided comprising an aluminum anode, an aqueous solution of permanganate as the cathodic species and a second electrode capable of reducing permanganate. Such a battery system is characterized by its high energy density and low polarization losses when operating at high temperatures in a strong caustic electrolyte, i.e., high concentration of hydroxyl ions. A variety of anode and electrocatalyst materials are suitable for the efficient oxidation-reduction process and are elucidated.

  1. Aluminum microstructures on anodic alumina for aluminum wiring boards.

    PubMed

    Jha, Himendra; Kikuchi, Tatsuya; Sakairi, Masatoshi; Takahashi, Hideaki

    2010-03-01

    The paper demonstrates simple methods for the fabrication of aluminum microstructures on the anodic oxide film of aluminum. The aluminum sheets were first engraved (patterned) either by laser beam or by embossing to form deep grooves on the surface. One side of the sheet was then anodized, blocking the other side by using polymer mask to form the anodic alumina. Because of the lower thickness at the bottom part of the grooves, the part was completely anodized before the complete oxidation of the other parts. Such selectively complete anodizing resulted in the patterns of metallic aluminum on anodic alumina. Using the technique, we fabricated microstructures such as line patterns and a simple wiring circuit-board-like structure on the anodic alumina. The aluminum microstructures fabricated by the techniques were embedded in anodic alumina/aluminum sheet, and this technique is promising for applications in electronic packaging and devices. PMID:20356280

  2. Parametric Optimization of Simulated Extrusion of Square to Square Section Through Linear Converging Die

    NASA Astrophysics Data System (ADS)

    Mohapatra, S. K.; Maity, K. P.

    2016-02-01

    The effect of various process parameters for determining extrusion load has been studied for square to square extrusion of Al-6061 alloy, a most used aluminium alloy series in forming industries. Parameters like operating temperature, friction condition, ram velocity, extrusion ratio and die length have been chosen as an input variable for the above study. Twenty five combinations of parameters were set for the investigation by considering aforementioned five parameters in five levels. The simulations have been carried out by Deform-3D software for predicting maximum load requirement for the complete extrusion process. Effective stress and strain distribution across the billet has been checked. Operating temperature, extrusion ratio, friction factor, ram velocity and die length have the significant effect in decreasing order on the maximum load requirement.

  3. Crystal plasticity finite element modelling of the extrusion texture of a magnesium alloy

    NASA Astrophysics Data System (ADS)

    Shao, Yichuan; Tang, Tao; Li, Dayong; Tang, Weiqin; Peng, Yinghong

    2015-07-01

    In this paper, a crystal plasticity finite-element model (CPFEM) is developed to simulate the hot extrusion texture of the magnesium alloy AZ31. The crystal plasticity model is implemented in ABAQUS™ via user interface VUMAT subroutine. The elasto-plastic self-consistent (EPSC) model is used as the basic polycrystal framework to simulate the slip and twinning during the extrusion. Furthermore, this framework is extended to account for the effects of the dynamically recrystallized (DRX) grains on the extrusion textures. Good agreement is found between the experimentally measured and simulated textures. The simulation results show that the presence of a secondary texture component around < 11.0> || extrusion direction (ED) can be attributed to the lattice rotation around the c-axis during the formation of the DRX grains. In addition, the shear strain imposed on the extruded material affects the resulting texture by enhancing the basal < a> slip mode as the material passes through the extrusion opening.

  4. Ashtabula Environmental Management Project Main Extrusion Plant Demolition Project. Demolition of the Ashtabula Environmental Management Project's Main Extrusion Plant

    SciTech Connect

    Colborn, Kurt; Johnson, Kathryn K.

    2003-02-27

    Significant progress was made this year toward closure of the Department of Energy's Ashtabula Environmental Management Project (AEMP) with the demolition of the 9-building Main Extrusion Plant Complex. The 44,000 square foot building complex formerly housed uranium extrusion facilities and equipment. At the start of the project in October of 2001, the buildings still contained a RCRA Part B storage area, operating mixed waste treatment facilities, active waste shredding and compacting process areas, and a state EPA permitted HEPA ventilation system. This paper presents a discussion of the multidisciplinary effort to bring the building to a safe shutdown condition in just six months, including relocation of existing process areas, utility isolation, and preliminary decontamination. Also discussed is the demolition strategy in which portions of the facility remained active while demolition was proceeding in other areas. Other details of the technical approach to the demolition are also discussed, including innovative techniques for demolition, galbestos removal, contamination control, and waste minimization. These techniques contributed to the early completion of demolition in July of 2002, fully two months ahead of schedule and $1.5 million under budget.

  5. Aluminum Carbothermic Technology

    SciTech Connect

    Bruno, Marshall J.

    2005-03-31

    This report documents the non-proprietary research and development conducted on the Aluminum Carbothermic Technology (ACT) project from contract inception on July 01, 2000 to termination on December 31, 2004. The objectives of the program were to demonstrate the technical and economic feasibility of a new carbothermic process for producing commercial grade aluminum, designated as the ''Advanced Reactor Process'' (ARP). The scope of the program ranged from fundamental research through small scale laboratory experiments (65 kW power input) to larger scale test modules at up to 1600 kW power input. The tasks included work on four components of the process, Stages 1 and 2 of the reactor, vapor recovery and metal alloy decarbonization; development of computer models; and economic analyses of capital and operating costs. Justification for developing a new, carbothermic route to aluminum production is defined by the potential benefits in reduced energy, lower costs and more favorable environmental characteristics than the conventional Hall-Heroult process presently used by the industry. The estimated metrics for these advantages include energy rates at approximately 10 kWh/kg Al (versus over 13 kWh/kg Al for Hall-Heroult), capital costs as low as $1250 per MTY (versus 4,000 per MTY for Hall-Heroult), operating cost reductions of over 10%, and up to 37% reduction in CO2 emissions for fossil-fuel power plants. Realization of these benefits would be critical to sustaining the US aluminum industries position as a global leader in primary aluminum production. One very attractive incentive for ARP is its perceived ability to cost effectively produce metal over a range of smelter sizes, not feasible for Hall-Heroult plants which must be large, 240,000 TPY or more, to be economical. Lower capacity stand alone carbothermic smelters could be utilized to supply molten metal at fabrication facilities similar to the mini-mill concept employed by the steel industry. Major

  6. Effect of heat treatment on microstructures and mechanical properties of a Ti-6Al-4V alloy rod prepared by powder compact extrusion

    NASA Astrophysics Data System (ADS)

    Yang, Fei; Gabbitas, Brian

    2015-03-01

    In this paper, Ti-6Al-4V alloy rods were manufactured by the powder compact extrusion of a powder mixture of hydride-dehydride (HDH) titanium powder, elemental aluminum powder and master alloy powder. Extrusions were carried out at 1300°C and with a holding time of 5 min in an argon atmosphere. The effects of different heat treatments (HT1: 960°C/1 h, water quenching, HT2: 960°C/1 h, water quenching + 500°C/6 h, air cooling, HT3: 850°C/2 h, furnace cooling to 540°C, then air cooling) on the microstructure and mechanical properties of as-extruded Ti-6Al-4V alloy rods were investigated. The results showed that a homogeneous microstructure, composed of a lamellar structure with a grain size range of 40-60 μm, was produced by powder compact extrusion of a powder mixture. The mechanical properties achieved were an ultimate tensile strength (UTS) of 1254 MPa, a yield strength (YS) of 1216 MPa and 8% ductility. After quenching at 960°C and with a holding time of 1 h, the UTS and YS of the heat treated Ti-6Al-4V alloy rod were increased to 1324 MPa and 1290 MPa, and the ductility was increased to 12%. After HT2, the UTS and YS of the heat treated Ti-6Al-4V alloy rod were significantly increased to 1436 MPa and 1400 MPa, but the ductility decreased to 4%. After HT3, the mechanical properties of the heat treated Ti-6Al-4V alloy rod were slightly decreased to give a UTS of 1213 MPa and a YS of 1180 MPa, with an increase in ductility to 11%. The microstructural changes of as-extruded Ti-6Al-4V alloy rods were also investigated for the different heat treatments.

  7. Cryogenic Properties of Aluminum-Beryllium and Beryllium Materials

    NASA Technical Reports Server (NTRS)

    Gamwell, Wayne R.; McGill, Preston B.

    2003-01-01

    Ultimate tensile strength, yield strength, and elongation were obtained for the aluminum- beryllium alloy, AlBeMetl62 (38%Al-62%Be), at cryogenic (-195.5 C (-32O F) and (- 252.8 C) (-423 F)) temperatures, and for an optical grade beryllium, O-30H (99%Be), at -252.8 C. AlBeMet162 material was purchased to the requirements of SAE- AMs7912, "Aluminum-Beryllium Alloy, Extrusions". O-30H material was purchased to the requirements of Brush Wellman Inc. specification O-30H Optical Grade Beryllium. The ultimate tensile and yield strengths for extruded AlBeMet162 material increased with decreasing temperature, and the percent elongation decreased with decreasing temperature. Design properties for the ultimate tensile strength, yield strength, and percent elongation for extruded AlBeMetl62 were generated. It was not possible to distinguish a difference in the room and cryogenic ultimate strength for the hot isostatically pressed (HIP'ed) O-30H material. The O-30H elongation decreased with decreasing temperature.

  8. Cryogenic Properties of Aluminum Beryllium and Beryllium Materials

    NASA Technical Reports Server (NTRS)

    Gamwell, Wayne R.; McGill, Preston B.

    2003-01-01

    Ultimate tensile strength, yield strength, and elongation were obtained for the aluminum-beryllium alloy, AlBeMetl62 (38%Al-62%Be), at cryogenic (-195.5 C (-320 F) and (-252.8 C) (-423 F)) temperatures, and for an optical grade beryllium, O-30H (99%Be), at -252.8 C. AlBeMetl62 material was purchased to the requirements of SAE-AMS7912, "Aluminum-Beryllium Alloy, Extrusions." O-30H material was purchased to the requirements of Brush Wellman Inc. specification O-30H Optical Grade Beryllium. The ultimate tensile and yield strengths for extruded AlBeMetl62 material increased with decreasing temperature, and the percent elongation decreased with decreasing temperature. Design properties for the ultimate tensile strength, yield strength, and percent elongation for extruded AlBeMetl62 were generated. It was not possible to distinguish a difference in the room and cryogenic ultimate strength for the hot isostatically pressed (HIP'ed) O-30H material. The O30H elongation decreased with decreasing temperature.

  9. Bearing Strengths of Some Wrought-aluminum Alloys

    NASA Technical Reports Server (NTRS)

    Moore, R L; Wescoat, C

    1943-01-01

    Although a number of investigations of the bearing strength of aluminum alloys have been made, the problem remains one of considerable interest to the aircraft industry. For this reason it has seemed advisable to make additional tests of the commonly used aircraft alloys in an effort to establish a better basis for the selection of allowable bearing values. Current design practice does not recognize the effect of edge distance upon bearing strengths, and for this reason edge distance was one of the principal variables considered in this investigation. The increasing emphasis being placed upon permanent set limitations makes it essential that more information on bearing yield phenomena be obtained. The object of this investigation was to determine bearing yield and ultimate strengths of the following aluminum alloy products: 17S-T, 24S-T, Alclad 24S-T, 24S-RT, 52S-0, 52S-1/2H, 52S-H, 53S-T, and 61S-T extrusions. Ratios of these bearing properties to tensile properties were also determined.

  10. Extracting aluminum from dross tailings

    NASA Astrophysics Data System (ADS)

    Amer, A. M.

    2002-11-01

    Aluminum dross tailings, an industrial waste, from the Egyptian Aluminium Company (Egyptalum) was used to produce two types of alums: aluminum-sulfate alum [itAl2(SO4)3.12H2O] and ammonium-aluminum alum [ (NH 4)2SO4AL2(SO4)3.24H2O]. This was carried out in two processes. The first process is leaching the impurities using diluted H2SO4 with different solid/liquid ratios at different temperatures to dissolve the impurities present in the starting material in the form of solute sulfates. The second process is the extraction of aluminum (as aluminum sulfate) from the purifi ed aluminum dross tailings thus produced. The effects of temperature, time of reaction, and acid concentration on leaching and extraction processes were studied. The product alums were analyzed using x-ray diffraction and thermal analysis techniques.

  11. 21 CFR 73.1645 - Aluminum powder.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Aluminum powder. 73.1645 Section 73.1645 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1645 Aluminum powder. (a) Identity. (1) The color additive aluminum powder shall be composed of finely divided particles of aluminum prepared from virgin aluminum....

  12. 21 CFR 73.1645 - Aluminum powder.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Aluminum powder. 73.1645 Section 73.1645 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1645 Aluminum powder. (a) Identity. (1) The color additive aluminum powder shall be composed of finely divided particles of aluminum prepared from virgin aluminum....

  13. 21 CFR 73.1645 - Aluminum powder.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Aluminum powder. 73.1645 Section 73.1645 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1645 Aluminum powder. (a) Identity. (1) The color additive aluminum powder shall be composed of finely divided particles of aluminum prepared from virgin aluminum....

  14. 21 CFR 73.1645 - Aluminum powder.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Aluminum powder. 73.1645 Section 73.1645 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1645 Aluminum powder. (a) Identity. (1) The color additive aluminum powder shall be composed of finely divided particles of aluminum prepared from virgin aluminum....

  15. 21 CFR 73.1645 - Aluminum powder.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Aluminum powder. 73.1645 Section 73.1645 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1645 Aluminum powder. (a) Identity. (1) The color additive aluminum powder shall be composed of finely divided particles of aluminum prepared from virgin aluminum....

  16. Exhumation and extrusion of the Great Himalaya Complex (GHC)

    NASA Astrophysics Data System (ADS)

    Xu, Zhiqin; Wang, Qi; Cao, Hui

    2013-04-01

    The predominant stretching lineation in the Great Himalaya Complex (GHC) trends perpendicular orogen, which has been attributed to southward exhumation of these mid-crustal rocks between the South Tibet Detachment (STD) and Main Central Thrust (MCT) in wedge extrusion (e.g., Burchfiel and Royden, 1985; Grujic et al., 1996) and channel flow models (e.g., Beaumont et al., 2001; Hodges et al., 2001; Grujic et al., 2002), or to emplacement of the GHC between the MCT and STD in tectonic wedging models (Yin, 2006; Webb et al., 2007, 2011a, b). Our new structural and geochronological data from southern Tibet demonstrate widespread lateral flow marked by orogen-parallel stretching lineation in the upper part of the GHC, which corresponds to decoupling between the high-grade GHC rocks and the overlying Tethyan Himalayan Sequence (THS). The kinematic framework reveals a top-to-the-east shear sense in the eastern GHC, both top-to-the-east and top-to-the-west shearing in the central GHC, and a top-to-the-west shear sense in the western GHC during the late Oligocene and Miocene. Geological observations along the Butwal-Pokhara- Jomsom cross section of the Central Nepal-Himalaya indicate that the STD is characterized by small-scale ductile normal shearing at the top part of the GHC and large-scale listric folding structures at the lower part of the Tethys Himalaya unit (TH) composed by Paleozoic- Mesozoic sediments. But the very wide thrusting deformation domain with about 8 km thickness existed in the both sides of the MCT shows possible ductile thrust shearing occurred earlier than We propose that exhumation and extrusion of the GHC probably experienced following complex processes: (1) Early Partial melting occurred at the deep part of the GHC at Eocene; (2) Orogen-parallel gravitational collapse in the late Oligocene and Miocene; (3) Exhumation of the GHC caused by thrusting and extrusion of the GHC between the MCT and STD at Miocene.

  17. Joining of aluminum and long fiber thermoplastic (LFT) composites

    NASA Astrophysics Data System (ADS)

    Kulkarni, Rahul R.

    Metal/polymer joints are used in variety of areas: aerospace, automotive, prosthetic devices, electronic packaging, etc. The present study involves a tailcone, which is currently made of aluminum and a new design will involve a joint between aluminum and long fiber thermoplastic (LFT) composite. The new tailcones were processed by insert molding, also called as extrusion-compression molding. Finite element (FE) models were used to obtain a temperature profile during cooling of tailcone from processing and to estimate thermal stresses generated. Experimental verification of the temperature profile was obtained by IR thermography. It was observed that the LFT part of the tailcone cooled faster than aluminum. During the cooling of the tailcone, the aluminum insert acted as a heat sink because of the large difference between the thermal conductivities of aluminum and the LFT composite. Thermal stresses computed were 2.5 MPa and 12 MPa in the case of beaded and threaded insert tailcones, respectively. Static pullout tests were done to obtain an insight into the failure mechanisms of the joint between aluminum and LFT composite. Both the tailcone configurations, with beaded and threaded inserts, showed about the same average peak load, 96 kN. Radiographic and metallographic studies showed that the damage at the interface between aluminum and LFT composite occurred in the form of microcracks, followed by complete separation normal to the stress axis. The tailcones housed in projectiles were test fired and it was found that the HBTs disintegrated immediately after they came out of the barrel. A new design was proposed to overcome the drawbacks of the HBTs, called filled-back tailcone (FBT). Static pullout tests on FBTs showed no failure of the tailcones, which was in accord with the test firing where tailcone did not fail. The study of aluminum/LFT composite interfaces was extended into the realm of laminated composites. Laminated composites were made in the form of

  18. Quasicrystalline particulate reinforced aluminum composite

    SciTech Connect

    Anderson, I.E.; Biner, S.B.; Sordelet, D.J.; Unal, O.

    1997-07-01

    Particulate reinforced aluminum and aluminum alloy composites are rapidly emerging as new commercial materials for aerospace, automotive, electronic packaging and other high performance applications. However, their low processing ductility and difficulty in recyclability have been the key concern. In this study, two composite systems having the same aluminum alloy matrix, one reinforced with quasicrystals and the other reinforced with the conventional SiC reinforcements were produced with identical processing routes. Their processing characteristics and tensile mechanical properties were compared.

  19. Cathodic phenomena in aluminum electrowinning

    NASA Astrophysics Data System (ADS)

    Bouteillon, J.; Poignet, J. C.; Rameau, J. J.

    1993-02-01

    Although aluminum is one of the world's highest production-volume primary metals, it is particularly costly to produce for a variety of factors, not the least of which are the expenses associated with electrolytic reduction. Based on the scale of global aluminum processing, even minor improvements in the electrowinning technology can result in significant savings of resources. Thus, from this perspective, the following reviews recent studies of cathodic phenomena in aluminum electrowinning.

  20. Laser welding of aluminum alloys

    SciTech Connect

    Leong, K.H.; Sabo, K.R.; Sanders, P.G.; Spawr, W.J.

    1997-03-01

    Recent interest in reducing the weight of automobiles to increase fuel mileage has focused attention on the use of aluminum and associated joining technologies. Laser beam welding is one of the more promising methods for high speed welding of aluminum. Consequently, substantial effort has been expended in attempting to develop a robust laser beam welding process. Early results have not been very consistent in the process requirements but more definitive data has been produced recently. This paper reviews the process parameters needed to obtain consistent laser welds on 5,000 series aluminum alloys and discusses the research necessary to make laser processing of aluminum a reality for automotive applications.

  1. Mineral of the month: aluminum

    USGS Publications Warehouse

    Plunkert, Patricia A.

    2005-01-01

    Aluminum is the second most abundant metallic element in Earth’s crust after silicon. Even so, it is a comparatively new industrial metal that has been produced in commercial quantities for little more than 100 years. Aluminum is lightweight, ductile, malleable and corrosion resistant, and is a good conductor of heat and electricity. Weighing about one-third as much as steel or copper per unit of volume, aluminum is used more than any other metal except iron. Aluminum can be fabricated into desired forms and shapes by every major metalworking technique to add to its versatility.

  2. Optimization of microstructure development: Application to hot metal extrusion

    SciTech Connect

    Medina, E.A.; Venugopal, S.; Frazier, W.G.; Medeiros, S.; Mullins, W.M.; Chaudhary, A.; Malas, J.C.; Srinivasan, R.

    1996-12-01

    A new process design method for controlling microstructure development during hot metal deformation processes is presented. This approach is based on modern control theory and involves state-space models for describing the material behavior and the mechanics of the process. The challenge of effectively controlling the values and distribution of important microstructural features can now be systematically formulated and solved in terms of an optimal control problem. This method has been applied to the optimization of grain size and certain process parameters such as die geometry profile and ram velocity during extrusion of plain carbon steel. Various case studies have been investigated, and experimental results show good agreement with those predicted in the design stage.

  3. Tissue damage after sodium hypochlorite extrusion during root canal treatment.

    PubMed

    de Sermeño, Ruth Fuentes; da Silva, Léa Assed Bezerra; Herrera, Henry; Herrera, Helen; Silva, Raquel Assed Bezerra; Leonardo, Mário Roberto

    2009-07-01

    Sodium hypochlorite solution is toxic to vital tissues, causing severe effects if extruded during endodontic treatment. This paper presents a report on the tissue damage related to inadvertent extrusion of concentrated sodium hypochlorite solution during root canal treatment. A 65-year-old woman was referred with moderate pain, ecchymosis, and severe swelling of the right side of the face. These symptoms appeared immediately after a root canal treatment of the maxillary right canine, which had been started 21 hours earlier. It was diagnosed as air emphysema related to sodium hypochlorite solution extravasation during the endodontic treatment. To avoid this, an initial radiograph should be taken to determine the correct canal working length and confirm root canal integrity. PMID:19442541

  4. Optimization of an Extrusion Die for Polymer Flow

    NASA Astrophysics Data System (ADS)

    Ridene, Y. Chahbani; Graebling, D.; Boujelbene, M.

    2011-01-01

    In this work, we used the CFD software PolyFlow to optimize the extrusion process of polystyrene flow. In this process, the flow of the molten polymer through the die can be viewed as a critical step for the material in terms of shear rate, self heating by viscous dissipation and temperature reached. The simulation is focused on the flow and heat transfer in the die to obtain a uniform velocity profile and a uniform temperature profile. The rheological behavior of polymer melt was described by the nonlinear Giesekus model. The dependence of the viscosity has also to be taken into account for a correct description of the flow. The design of the die has been validated by our numerical simulation.

  5. Simulation of a Full Forward Extrusion Process from Metal Strip

    NASA Astrophysics Data System (ADS)

    Merklein, Marion; Stellin, Tommaso; Engel, Ulf

    2011-05-01

    The interest on mass production of small complex metal components is currently fostered by fields like electronics and micromechanics. A possible approach is seen in a multi-step bulk forming process, limited among scaling problems by handling difficulties between the forming stages. A radical simplification of the positioning of the workpiece is seen in a process in which a metal strip acts both as raw material and support of the workpiece through the different forming stages. Within the study of this method, a full forward extrusion process from metal strip has been simulated with the goal of getting the basic knowledge about the strip behavior and process performance. The influence of the main geometric and tribological features has been evaluated designing a full factorial plan. The role of the radius of curvature of the tool edges and of the factor of friction have become the points of main interest in the optimization of the process.

  6. Modelling the extrusion of preforms for microstructured optical fibres

    NASA Astrophysics Data System (ADS)

    Tronnolone, Hayden; Stokes, Yvonne; Crowdy, Darren

    2013-11-01

    Owing to a novel design, microstructured optical fibres (MOFs) promise the realisation of fibres with effectively any desired optical properties. MOFs are typically constructed from glass and employ a series of air channels aligned along the fibre axis to form a waveguide. The construction of MOFs by first extruding a preform and then drawing this into the final fibre has the potential to produce fibres on an industrial scale; however, this is hindered by a limited understanding of the fluid flow that arises during this process. We focus on the extrusion stage of fabrication and discuss a model of the fibre evolution based upon complex-variable techniques. The relative influence of the various physical processes involved is discussed, along with limitations of the model.

  7. Optimization of microstructure development: application to hot metal extrusion

    NASA Astrophysics Data System (ADS)

    Medina, E. A.; Venugopal, S.; Frazier, W. G.; Medeiros, S.; Mulhns, W. M.; Chaudhary, A.; Irwin, R. D.; Srinivasan, R.; Malas, J. C.

    1996-12-01

    A new process design method for controlling microstructure development during hot metal deformation processes is presented. This approach is based on modern control theory and involves state- space models for describing the material behavior and the mechanics of the process. The challenge of effectively controlling the values and distribution of important microstructural features can now be systematically formulated and solved in terms of an optimal control problem. This method has been applied to the optimization of grain size and certain process parameters such as die geometry profile and ram velocity during extrusion of plain carbon steel. Various case studies have been investigated, and experimental results show good agreement with those predicted in the design stage.

  8. Processing of cylindrical hollow parts: piercing vs. extrusion

    NASA Astrophysics Data System (ADS)

    Comăneci, R.; Zaharia, L.; Nedelcu, D.; Bujoreanu, L. G.

    2015-11-01

    As work principle, piercing (P) and backward extrusion (BE) are similar deforming processes. However, working-load, strain and material flow are quiet different depending on real conditions. Since punch diameter d and workpiece diameter D are the defining parameters for both P and BE, there is a critical d/D ratio separating them as distinctive operations. To have a complete description of P and BE in terms of working load and yield pressure as function of d/D ratio, experimental tests and numerical predictions were conducted. Tridimensional finite element analysis (FEA) for different process designs (i.e. different d/D ratios) revealed distinctive evolutions of the material flow establishing the effective limits of P and BE respectively. Experimental and numerical results can be used in practice to provide estimates of working-load, critical yield pressure and tool dimensions for optimal P and BE in processing of cylindrical hollow parts.

  9. Scalable Approach for Extrusion and Perfusion of Tubular, Heterotypic Biomaterials

    NASA Astrophysics Data System (ADS)

    Jeronimo, Mark David

    Soft material tubes are critical in the vasculature of mammalian tissues, forming networks of blood vessels and airways. Homogeneous and heterogeneous hydrogel tubes were extruded in a one-step process using a three layer microfluidic device. Co-axial cylindrical flow of crosslinking solutions and an alginate matrix is generated by a radial arrangement of microfluidic channels at the device's vertical extrusion outlet. The flow is confined and begins a sol-gel transition immediately as it extrudes at velocities upwards of 4 mm/s. This approach allows for predictive control over the dimensions of the rapidly formed tubular structures for outer diameters from 600 microm to 3 mm. A second microfluidic device hosts tube segments for controlled perfusion and pressurization using a reversible vacuum seal. On-chip tube deflection is observed and modeled as a measure of material compliance and circumferential elasticity. I anticipate applications of these devices for perfusion cell culture of cell-laden hydrogel tubes.

  10. Production of aluminum metal by electrolysis of aluminum sulfide

    DOEpatents

    Minh, N.Q.; Loutfy, R.O.; Yao, N.P.

    1982-04-01

    Metallic aluminum may be produced by the electrolysis of Al/sub 2/S/sub 3/ at 700 to 800/sup 0/C in a chloride melt composed of one or more alkali metal chlorides, and one or more alkaline earth metal chlorides and/or aluminum chloride to provide improved operating characteristics of the process.

  11. Production of aluminum metal by electrolysis of aluminum sulfide

    DOEpatents

    Minh, Nguyen Q.; Loutfy, Raouf O.; Yao, Neng-Ping

    1984-01-01

    Production of metallic aluminum by the electrolysis of Al.sub.2 S.sub.3 at 700.degree.-800.degree. C. in a chloride melt composed of one or more alkali metal chlorides, and one or more alkaline earth metal chlorides and/or aluminum chloride to provide improved operating characteristics of the process.

  12. Critical properties of aluminum.

    PubMed

    Bhatt, Divesh; Jasper, Ahren W; Schultz, Nathan E; Siepmann, J Ilja; Truhlar, Donald G

    2006-04-01

    Gibbs ensemble Monte Carlo calculations are performed using a validated embedded-atom potential to obtain the vapor-liquid coexistence curve for elemental aluminum in good agreement with available experimental data up to the boiling point. These calculations are then extended to make a reliable prediction of the critical temperature, pressure, and density of Al, which have previously been known only with very large uncertainties. This demonstrates the ability of modern simulations to predict fundamental physical properties that are extremely difficult to measure directly. PMID:16568986

  13. Selective Adsorption of Sodium Aluminum Fluoride Salts from Molten Aluminum

    SciTech Connect

    Leonard S. Aubrey; Christine A. Boyle; Eddie M. Williams; David H. DeYoung; Dawid D. Smith; Feng Chi

    2007-08-16

    Aluminum is produced in electrolytic reduction cells where alumina feedstock is dissolved in molten cryolite (sodium aluminum fluoride) along with aluminum and calcium fluorides. The dissolved alumina is then reduced by electrolysis and the molten aluminum separates to the bottom of the cell. The reduction cell is periodically tapped to remove the molten aluminum. During the tapping process, some of the molten electrolyte (commonly referred as “bath” in the aluminum industry) is carried over with the molten aluminum and into the transfer crucible. The carryover of molten bath into the holding furnace can create significant operational problems in aluminum cast houses. Bath carryover can result in several problems. The most troublesome problem is sodium and calcium pickup in magnesium-bearing alloys. Magnesium alloying additions can result in Mg-Na and Mg-Ca exchange reactions with the molten bath, which results in the undesirable pickup of elemental sodium and calcium. This final report presents the findings of a project to evaluate removal of molten bath using a new and novel micro-porous filter media. The theory of selective adsorption or removal is based on interfacial surface energy differences of molten aluminum and bath on the micro-porous filter structure. This report describes the theory of the selective adsorption-filtration process, the development of suitable micro-porous filter media, and the operational results obtained with a micro-porous bed filtration system. The micro-porous filter media was found to very effectively remove molten sodium aluminum fluoride bath by the selective adsorption-filtration mechanism.

  14. Microstructure evolution in age-hardenable aluminium alloy during processing by hydrostatic extrusion.

    PubMed

    Lewandowska, M

    2006-10-01

    In the present work, scanning and transmission electron microscopy were used to investigate the microstructural evolution occurring during the hydrostatic extrusion of an age-hardenable aluminium alloy. It was shown that processing by hydrostatic extrusion leads to grain refinement to 95 nm in equivalent diameter. Hydrostatic extrusion also influences the geometrical parameters of two different types of particle: intermetallic inclusions and precipitates. The intermetallic inclusions slightly decrease in mean equivalent diameter, but their size remains at the micrometre level. The precipitates are fragmented to nanoscale spherical particles, and their evolution delays the process of grain refinement. PMID:17100901

  15. Structural and mechanical properties of nanocrystalline titanium and 316LVM steel processed by hydrostatic extrusion.

    PubMed

    Garbacz, Halina; Lewandowska, Małgorzata; Pachla, Wacław; Kurzydłowski, Krzysztof J

    2006-09-01

    The aim of the present study was to examine the potential of hydrostatic extrusion for the fabrication of high-strength materials for medical applications. The materials examined were 316LVM steel and technically pure titanium. The microstructures and mechanical properties of the materials before and after hydrostatic extrusion were analysed. It was found that the hydrostatic extrusion process resulted in a substantial refinement of the material microstructures. The refinement of the microstructure was accompanied by an improvement of the mechanical properties, such as the microhardness and yield stress. PMID:17059548

  16. Aluminum Nanoholes for Optical Biosensing.

    PubMed

    Barrios, Carlos Angulo; Canalejas-Tejero, Víctor; Herranz, Sonia; Urraca, Javier; Moreno-Bondi, María Cruz; Avella-Oliver, Miquel; Maquieira, Ángel; Puchades, Rosa

    2015-01-01

    Sub-wavelength diameter holes in thin metal layers can exhibit remarkable optical features that make them highly suitable for (bio)sensing applications. Either as efficient light scattering centers for surface plasmon excitation or metal-clad optical waveguides, they are able to form strongly localized optical fields that can effectively interact with biomolecules and/or nanoparticles on the nanoscale. As the metal of choice, aluminum exhibits good optical and electrical properties, is easy to manufacture and process and, unlike gold and silver, its low cost makes it very promising for commercial applications. However, aluminum has been scarcely used for biosensing purposes due to corrosion and pitting issues. In this short review, we show our recent achievements on aluminum nanohole platforms for (bio)sensing. These include a method to circumvent aluminum degradation--which has been successfully applied to the demonstration of aluminum nanohole array (NHA) immunosensors based on both, glass and polycarbonate compact discs supports--the use of aluminum nanoholes operating as optical waveguides for synthesizing submicron-sized molecularly imprinted polymers by local photopolymerization, and a technique for fabricating transferable aluminum NHAs onto flexible pressure-sensitive adhesive tapes, which could facilitate the development of a wearable technology based on aluminum NHAs. PMID:26184330

  17. The Benefits of Aluminum Windows.

    ERIC Educational Resources Information Center

    Goyal, R. C.

    2002-01-01

    Discusses benefits of aluminum windows for college construction and renovation projects, including that aluminum is the most successfully recycled material, that it meets architectural glass deflection standards, that it has positive thermal energy performance, and that it is a preferred exterior surface. (EV)

  18. Primary Aluminum Plants Worldwide - 1998

    USGS Publications Warehouse

    1999-01-01

    The 1990 U.S. Bureau of Mines publication, Primary Aluminum Plants Worldwide, has been updated and is now available. The 1998 USGS edition of Primary Aluminum Plants Worldwide is published in two parts. Part I—Detail contains information on individual primary smelter capacity, location, ownership, sources of energy, and other miscellaneous information. Part II—Summary summarizes the capacity data by country

  19. Lost-Soap Aluminum Casting.

    ERIC Educational Resources Information Center

    Mihalow, Paula

    1980-01-01

    Lost-wax casting in sterling silver is a costly experience for the average high school student. However, this jewelry process can be learned at no cost if scrap aluminum is used instead of silver, and soap bars are used instead of wax. This lost-soap aluminum casting process is described. (Author/KC)

  20. Boron carbide-aluminum cermets

    SciTech Connect

    Halverson, D.C.

    1986-09-03

    We have developed boron carbide-aluminum cermets by means of thermodynamic, kinetic, and processing studies. Our research indicates that boron carbide-aluminum cermets offer ''tailorable'' microstructures with designable properties through process control. This new class of cermets has the potential to become a very important material with wide industrial applications.

  1. Aluminum Nanoholes for Optical Biosensing

    PubMed Central

    Barrios, Carlos Angulo; Canalejas-Tejero, Víctor; Herranz, Sonia; Urraca, Javier; Moreno-Bondi, María Cruz; Avella-Oliver, Miquel; Maquieira, Ángel; Puchades, Rosa

    2015-01-01

    Sub-wavelength diameter holes in thin metal layers can exhibit remarkable optical features that make them highly suitable for (bio)sensing applications. Either as efficient light scattering centers for surface plasmon excitation or metal-clad optical waveguides, they are able to form strongly localized optical fields that can effectively interact with biomolecules and/or nanoparticles on the nanoscale. As the metal of choice, aluminum exhibits good optical and electrical properties, is easy to manufacture and process and, unlike gold and silver, its low cost makes it very promising for commercial applications. However, aluminum has been scarcely used for biosensing purposes due to corrosion and pitting issues. In this short review, we show our recent achievements on aluminum nanohole platforms for (bio)sensing. These include a method to circumvent aluminum degradation—which has been successfully applied to the demonstration of aluminum nanohole array (NHA) immunosensors based on both, glass and polycarbonate compact discs supports—the use of aluminum nanoholes operating as optical waveguides for synthesizing submicron-sized molecularly imprinted polymers by local photopolymerization, and a technique for fabricating transferable aluminum NHAs onto flexible pressure-sensitive adhesive tapes, which could facilitate the development of a wearable technology based on aluminum NHAs. PMID:26184330

  2. Influence of Surface Preparation on the Kinetics of Controlled Gas-Nitrided AISI H13 Steels Used in Extrusion Dies

    NASA Astrophysics Data System (ADS)

    Akhtar, S. S.; Arif, A. F. M.; Yilbas, B. S.; Sheikh, A. K.

    2010-04-01

    In the aluminum extrusion practice, gas nitriding represents an important factor in enhancing the service life of AISI H13 steel dies. It is observed that if the die-bearing surface is not adequately prepared before nitriding, a nonuniform and shallow nitrided layer develops with reduced hardening effect. The focus of this paper is to investigate the influence of different surface conditions in terms of roughness on the kinetics of nitrided layer developed during gas-nitriding process under controlled nitriding potential. Four samples made of AISI H13 steel properly heat treated (quenched and tempered) were considered: without surface preparation, ground, polished, and lapped. All the samples were gas nitrided under the same conditions and examined after being nitrided. The nitrided layers were characterized using different techniques including optical microscopy, scanning electron microscopy, x-ray diffraction analysis, energy dispersive spectrometry mapping, and microhardness analysis. It was found that the surface preparation prior to nitriding significantly enhanced the nitriding kinetics, which in turn resulted in even and deep nitrided case depth. This provided high load-bearing capacity due to increased and deep hardening effect as compared to unprepared sample. A thinner and uniform compound layer with well-resolved phases was achieved in comparison with unprepared sample.

  3. Molecularly designed lipid microdomains for solid dispersions using a polymer/inorganic carrier matrix produced by hot-melt extrusion.

    PubMed

    Adler, Camille; Schönenberger, Monica; Teleki, Alexandra; Kuentz, Martin

    2016-02-29

    Amorphous solid dispersions have for many years been a focus in oral formulations, especially in combination with a hot-melt extrusion process. The present work targets a novel approach with a system based on a fatty acid, a polymer and an inorganic carrier. It was intended to adsorb the acidic lipid by specific molecular interactions onto the solid carrier to design disorder in the alkyl chains of the lipid. Such designed lipid microdomains (DLM) were created as a new microstructure to accommodate a compound in a solid dispersion. Vibrational spectroscopy, X-ray powder diffraction, atomic force microscopy as well as electron microscopic imaging were employed to study a system of stearic acid, hydroxypropylcellulose and aluminum magnesium silicate. β-carotene was used as a poorly water-soluble model substance that is difficult to formulate with conventional solid dispersion formulations. The results indicated that the targeted molecular excipient interactions indeed led to DLMs for specific compositions. The different methods provided complementary aspects and important insights into the created microstructure. The novel delivery system appeared to be especially promising for the formulation of oral compounds that exhibit both high crystal energy and lipophilicity. PMID:26721729

  4. A mathematical model to predict the strength of aluminum alloys subjected to precipitation hardening

    SciTech Connect

    Qureshi, F.S.; Sheikh, A.K.; Rashid, M.

    1999-06-01

    A number of alloys, notably most of the aluminum alloys, can be heat treated by aging. This aging due to time-dependent precipitation hardening increases the strength and hardness as well as modifying other mechanical properties. Precipitation hardening has been a popular strengthening mechanism for many decades; therefore, extensive information is available in literature about the precipitation-hardening response of various series of aluminum alloys. The age-hardening response of these alloys is usually represented in graphical form as plotted between property changes and aging time for different temperatures. In designing a suitable precipitation-hardening strategy, one can refer to these graphs. However, for automatic control of aging furnaces, as well as for decision making regarding optimal selection of aging conditions (time/temperature combination), it is desirable to express these relationships in a formal mathematical structure. A mathematical model is developed in this article for widely used heat treatable aluminum alloys used in the extrusion industry. This model is a condensed representation of all {sigma} = f(T,t) curves in different series of aluminum alloys, and the parameters of this model characterize the various compositions of the alloys in the series.

  5. Channeling of aluminum in silicon

    SciTech Connect

    Wilson, R.G.; Hopkins, C.G.

    1985-05-15

    A systematic study of channeling of aluminum in the silicon crystal is reported. Depth distributions measured by secondary ion mass spectrometry are reported for 40-, 75-, and 150-keV aluminum channeled in the <100> and <110> directions of silicon. The profile dependence on alignment angle is shown for 150-keV aluminum in the <110> of silicon. Aluminum has low electronic stopping in silicon and corresponding deep channeled profiles are observed for aligned implants and deep channeling tails are observed on random implants. The maximum channeling range for 150-keV Al in <100> silicon is about 2.8 ..mu..m and is about 6.4 ..mu..m in <110> silicon. Some ions will reach the maximum channeling range even for 2/sup 0/ misalignment. Many of the deep channeling tails and ''supertails'' reported in earlier literature can be explained by the normal channeling of aluminum in silicon.

  6. 77 FR 74466 - Aluminum Extrusions From the People's Republic of China: Notice of Court Decision Not in Harmony...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-14

    ... Affirmative Countervailing Duty Determination, 76 FR 18521 (April 4, 2011) (Final Determination). \\2\\ See Mac... respondents and applied this rate as the all-others rate.\\5\\ \\5\\ See Final Determination, 76 FR at 18523, and... Republic of China: Preliminary Affirmative Countervailing Duty Determination, 75 FR 54302 (September...

  7. Extrusion and rheology of fine particulate ceramic pastes

    NASA Astrophysics Data System (ADS)

    Mazzeo, Fred Anthony

    A rheological study was conducted on an extruded blend of two alumina powders, Alcoa A-3500-SG and Reynolds ERC. These extruded blends were mixed in four compositions, varying in distribution modulus. This work focuses on the interaction of the composition components, mainly particle size distribution and amount of water at a constant binder amount. The rheological parameters of extruded pastes, Sigma, Tau, alpha and beta, were determined by using capillary rheometry modeling by the methodology set forth by Benbow and Bridgwater. This methodology makes use of capillary rheometer to determine extrusion parameters, which describe the flow behavior of a paste. The parameter values are indirectly determined by extrapolating high shear rate information obtained by the extrusion process. A goal of this research was to determine fundamental rheological properties directly from fundamental rheological equations of state. This was accomplished by assessing the material properties by using a dynamic stress rheometer. The rheological parameters used in this study to characterize the paste are elastic modulus, viscosity, tan delta, and relaxation time. This technique approaches a step closer in understanding the microstructural influence on flow behavior of a paste. This method directly determines rheological properties by using linear viscoelastic theory, giving a quantitative analysis of material properties. A strong correlation between the elastic modulus and sigma, and viscosity and alpha is shown to exist, indicating a relationship between these two techniques. Predictive process control methodology, based on particle packing modeling, quantitatively determined structural parameters useful in evaluating a composition. The determined parameters are: distribution modulus, interparticle separation distance, porosity, and particle crowding index, which are important to understand the extrudates packed state. A connection between the physical structure of the extrudate and its

  8. Aluminum Zintl anion moieties within sodium aluminum clusters

    SciTech Connect

    Wang, Haopeng; Zhang, Xinxing; Ko, Yeon Jae; Grubisic, Andrej; Li, Xiang; Ganteför, Gerd; Bowen, Kit H. E-mail: kiran@mcneese.edu; Schnöckel, Hansgeorg; Eichhorn, Bryan W.; Lee, Mal-Soon; Jena, P.; Kandalam, Anil K. E-mail: kiran@mcneese.edu; Kiran, Boggavarapu E-mail: kiran@mcneese.edu

    2014-02-07

    Through a synergetic combination of anion photoelectron spectroscopy and density functional theory based calculations, we have established that aluminum moieties within selected sodium-aluminum clusters are Zintl anions. Sodium–aluminum cluster anions, Na{sub m}Al{sub n}{sup −}, were generated in a pulsed arc discharge source. After mass selection, their photoelectron spectra were measured by a magnetic bottle, electron energy analyzer. Calculations on a select sub-set of stoichiometries provided geometric structures and full charge analyses for both cluster anions and their neutral cluster counterparts, as well as photodetachment transition energies (stick spectra), and fragment molecular orbital based correlation diagrams.

  9. Aluminum Zintl anion moieties within sodium aluminum clusters

    NASA Astrophysics Data System (ADS)

    Wang, Haopeng; Zhang, Xinxing; Ko, Yeon Jae; Grubisic, Andrej; Li, Xiang; Ganteför, Gerd; Schnöckel, Hansgeorg; Eichhorn, Bryan W.; Lee, Mal-Soon; Jena, P.; Kandalam, Anil K.; Kiran, Boggavarapu; Bowen, Kit H.

    2014-02-01

    Through a synergetic combination of anion photoelectron spectroscopy and density functional theory based calculations, we have established that aluminum moieties within selected sodium-aluminum clusters are Zintl anions. Sodium-aluminum cluster anions, NamAln-, were generated in a pulsed arc discharge source. After mass selection, their photoelectron spectra were measured by a magnetic bottle, electron energy analyzer. Calculations on a select sub-set of stoichiometries provided geometric structures and full charge analyses for both cluster anions and their neutral cluster counterparts, as well as photodetachment transition energies (stick spectra), and fragment molecular orbital based correlation diagrams.

  10. Aluminum Zintl anion moieties within sodium aluminum clusters.

    PubMed

    Wang, Haopeng; Zhang, Xinxing; Ko, Yeon Jae; Grubisic, Andrej; Li, Xiang; Ganteför, Gerd; Schnöckel, Hansgeorg; Eichhorn, Bryan W; Lee, Mal-Soon; Jena, P; Kandalam, Anil K; Kiran, Boggavarapu; Bowen, Kit H

    2014-02-01

    Through a synergetic combination of anion photoelectron spectroscopy and density functional theory based calculations, we have established that aluminum moieties within selected sodium-aluminum clusters are Zintl anions. Sodium-aluminum cluster anions, Na(m)Al(n)(-), were generated in a pulsed arc discharge source. After mass selection, their photoelectron spectra were measured by a magnetic bottle, electron energy analyzer. Calculations on a select sub-set of stoichiometries provided geometric structures and full charge analyses for both cluster anions and their neutral cluster counterparts, as well as photodetachment transition energies (stick spectra), and fragment molecular orbital based correlation diagrams. PMID:24511934

  11. First principles pseudopotential calculations on aluminum and aluminum alloys

    SciTech Connect

    Davenport, J.W.; Chetty, N.; Marr, R.B.; Narasimhan, S.; Pasciak, J.E.; Peierls, R.F.; Weinert, M.

    1993-12-31

    Recent advances in computational techniques have led to the possibility of performing first principles calculations of the energetics of alloy formation on systems involving several hundred atoms. This includes impurity concentrations in the 1% range as well as realistic models of disordered materials (including liquids), vacancies, and grain boundaries. The new techniques involve the use of soft, fully nonlocal pseudopotentials, iterative diagonalization, and parallel computing algorithms. This approach has been pioneered by Car and Parrinello. Here the authors give a review of recent results using parallel and serial algorithms on metallic systems including liquid aluminum and liquid sodium, and also new results on vacancies in aluminum and on aluminum-magnesium alloys.

  12. [New extrusion products in diet therapy of diseases of internal organs].

    PubMed

    Meshcheriakova, V A; Plotnikova, O A; Iatsyshina, T A; Sharafetdinov, Kh Kh; Faĭvishevskiĭ, M L; Lisina, T N

    1995-01-01

    Therapeutic effectiveness of 3 new extrusion foods was studied in control conditions of clinic of Institute of nutrition RAMS. The foods were produced by Institute of meat industry RAS on basis of meat resources and wheat brans. The samples of extrusion foods were differed by contents of protein (17-23 g%) and dietary fibers (up to 10%) and used in therapeutic diet for patients with insulin-dependent diabetes mellitus. It was shown that of all three extrusion foods caused decreasing of dyspeptic symptoms during first week of intake and normalisation of intestinal functions without using of laxatives unlike of control group of patients eating standard diabetic diet. It was shown also a decreasing of cholesterol in blood serum of patients received of extrusion foods No 1 and No 3. These samples are recommended for diet therapy and preventive nutrition of patients with metabolic disorders and hypomotoricity of intestinal tract as resources of dietary fibers and protein. PMID:8533391

  13. Method for producing through extrusion an anisotropic magnet with high energy product

    DOEpatents

    Chandhok, Vijay K.

    2004-09-07

    A method for producing an anisotropic magnet with high energy product through extrusion and, more specifically, by placing a particle charge of a composition from the which magnet is to be produced in a noncircular container, heating the container and particle charge and extruding the container and particle charge through a noncircular extrusion die in such a manner that one of the cross-sectional axes or dimension of the container and particle charge is held substantially constant during the extrusion to compact the particle charge to substantially full density by mechanical deformation produced during the extrusion to achieve a magnet with anisotropic magnetic properties along the axes or dimension thereof and, more specifically, a high energy product along the transverse of the smallest cross-sectional dimension of the extruded magnet.

  14. Carbon nanotube composites prepared by ultrasonically assisted twin screw extrusion

    NASA Astrophysics Data System (ADS)

    Lewis, Todd

    Two ultrasonic twin screw extrusion systems were designed and manufactured for the ultrasonic dispersion of multi-walled carbon nanotubes in viscous polymer matrices at residence times of the order of seconds in the ultrasonic treatment zones. The first design consisted of an ultrasonic slit die attachment in which nanocomposites were treated. A second design incorporated an ultrasonic treatment section into the barrel of the extruder to utilize the shearing of the polymer during extrusion while simultaneously applying treatment. High performance, high temperature thermoset phenylethynyl terminate imide oligomer (PETI-330) and two different polyetherether ketones (PEEK) were evaluated at CNT loadings up to 10 wt%. The effects of CNT loading and ultrasonic amplitude on the processing characteristics and rheological, mechanical, electrical, thermal and morphological properties of nanocomposites were investigated. PETI and PEEK nanocomposites showed a decrease in resistivity, an increase in modulus and strength and a decrease in strain at break and toughness with increased CNT loading. Ultrasonically treated samples showed a decrease in die pressure and extruder torque with increasing ultrasonic treatment and an increase in complex viscosity and storage modulus at certain ultrasonic treatment levels. Optical microscopy showed enhanced dispersion of the CNT bundles in ultrasonically treated samples. However, no significant improvement of mechanical properties was observed with ultrasonic treatment due to lack of adhesion between the CNT and matrix in the solid state. A curing model for PETI-330 was proposed that includes the induction and curing stages to predict the degree of cure of PETI-330 under non-isothermal conditions. Induction time parameters, rate constant and reaction order of the model were obtained based on differential scanning calorimetry (DSC) data. The model correctly predicted experimentally measured degrees of cure of compression molded plaques cured

  15. Aluminum plasmonic photocatalysis

    PubMed Central

    Hao, Qi; Wang, Chenxi; Huang, Hao; Li, Wan; Du, Deyang; Han, Di; Qiu, Teng; Chu, Paul K.

    2015-01-01

    The effectiveness of photocatalytic processes is dictated largely by plasmonic materials with the capability to enhance light absorption as well as the energy conversion efficiency. Herein, we demonstrate how to improve the plasmonic photocatalytic properties of TiO2/Al nano-void arrays by overlapping the localized surface plasmon resonance (LSPR) modes with the TiO2 band gap. The plasmonic TiO2/Al arrays exhibit superior photocatalytic activity boasting an enhancement of 7.2 folds. The underlying mechanisms concerning the radiative energy transfer and interface energy transfer processes are discussed. Both processes occur at the TiO2/Al interface and their contributions to photocatalysis are evaluated. The results are important to the optimization of aluminum plasmonic materials in photocatalytic applications. PMID:26497411

  16. Transcorneal extrusion of anterior chamber intraocular lenses. A report of three cases.

    PubMed

    McKnight, G T; Richards, S C; Apple, D J; Stanko, M L; O'Morchoe, D J; Solomon, K D

    1987-12-01

    We examined three cases of transcorneal extrusion of anterior chamber intraocular lenses. In each case a preexisting condition (rheumatoid arthritis, glaucoma, and herpes zoster ophthalmicus, respectively) contributed to corneal necrosis and subsequent extrusion of the pseudophakos. The clinicopathologic correlations of this condition are discussed, as well as some causes of corneal decompensation associated with anterior chamber lenses. We emphasize the need for careful evaluation of patients who have preexisting disease before intraocular lens implantation. PMID:3318770

  17. Spray Rolling Aluminum Strip

    SciTech Connect

    Lavernia, E.J.; Delplanque, J-P; McHugh, K.M.

    2006-05-10

    Spray forming is a competitive low-cost alternative to ingot metallurgy for manufacturing ferrous and non-ferrous alloy shapes. It produces materials with a reduced number of processing steps, while maintaining materials properties, with the possibility of near-net-shape manufacturing. However, there are several hurdles to large-scale commercial adoption of spray forming: 1) ensuring strip is consistently flat, 2) eliminating porosity, particularly at the deposit/substrate interface, and 3) improving material yield. Through this program, a new strip/sheet casting process, termed spray rolling, has been developed, which is an innovative manufacturing technique to produce aluminum net-shape products. Spray rolling combines the benefits of twin-roll casting and conventional spray forming, showing a promising potential to overcome the above hurdles associated with spray forming. Spray rolling requires less energy and generates less scrap than conventional processes and, consequently, enables the development of materials with lower environmental impacts in both processing and final products. Spray Rolling was developed as a collaborative project between the University of California-Davis, the Colorado School of Mines, the Idaho National Engineering and Environmental Laboratory, and an industry team. The following objectives of this project were achieved: (1) Demonstration of the feasibility of the spray rolling process at the bench-scale level and evaluation of the materials properties of spray rolled aluminum strip alloys; and (2) Demonstration of 2X scalability of the process and documentation of technical hurdles to further scale up and initiate technology transfer to industry for eventual commercialization of the process.

  18. Aluminum toxicity. Hematological effects.

    PubMed

    Mahieu, S; del Carmen Contini, M; Gonzalez, M; Millen, N; Elias, M M

    2000-01-01

    Sequential effects of intoxication with aluminum hydroxide (Al) (80 mg/Kg body weight, i.p., three times a week), were studied on rats from weaning and up to 28 weeks. The study was carried out on hematological and iron metabolism-related parameters on peripheral blood, at the end of the 1st, 2nd, 3rd, 4th, 5th and 6th months of exposure. As it was described that hematotoxic effects of Al are mainly seen together with high levels of uremia, renal function was measured at the same periods. The animals treated developed a microcytosis and was accompanied by a decrease in mean corpuscular hemoglobin (MCH). Significantly lower red blood cell counts (RBC million/microl) were found in rats treated during the 1st month. These values matched those obtained for control rats during the 2nd month. From the 3rd month onwards, a significant increase was observed as compared to control groups, and the following values were obtained by the 6th month: (T) 10.0 +/- 0.3 versus (C) 8.7 +/- 0.2 (million/microl). Both MCH and mean corpuscular volume (MCV) were found to be significantly lower in groups treated from the 2nd month. At the end of the 6th month the following values were found: MCH (T) 13.3 +/- 0.1 versus (C) 16.9 +/- 0.3 (pg); MCV (T) 42.1 +/- 0.7 versus (C) 51.8 +/- 0.9 (fl). Al was found responsible for lower serum iron concentration levels and in the percentage of transferrin saturation. Thus, although microcytic anemia constitutes an evidence of chronic aluminum exposure, prolonged exposure could lead to a recovery of hematocrit and hemoglobin concentration values with an increase in red cell number. Nevertheless, both microcytosis and the decrease of MCH would persist. These modifications took place without changes being observed in the renal function during the observation period. PMID:10643868

  19. Aluminum: Industry of the future

    SciTech Connect

    1998-11-01

    For over a century, the US aluminum industry has led the global market with advances in technology, product development, and marketing. Industry leaders recognize both the opportunities and challenges they face as they head into the 21st century, and that cooperative R and D is key to their success. In a unique partnership, aluminum industry leaders have teamed with the US Department of Energy`s Office of Industrial Technologies (OIT) to focus on innovative technologies that will help to strengthen the competitive position of the US aluminum industry and, at the same time, further important national goals. This industry-led partnership, the Aluminum Industry of the Future, promotes technologies that optimize the use of energy and materials in operations and reduce wastes and energy-related emissions. Led by The Aluminum Association, industry leaders began by developing a unified vision of future market, business, energy, and environmental goals. Their vision document, Partnerships for the Future, articulates a compelling vision for the next 20 years: to maintain and grow the aluminum industry through the manufacture and sale of competitively priced, socially desirable, and ecologically sustainable products. Continued global leadership in materials markets will require the combined resources of industry, universities, and government laboratories. By developing a unified vision, the aluminum industry has provided a framework for the next step in the Industries of the Future process, the development of a technology roadmap designed to facilitate cooperative R and D.

  20. Shuttle Primary Reaction Control Subsystem Thruster Fuel Valve Pilot Seal Extrusion: A Failure Correlation

    NASA Technical Reports Server (NTRS)

    Waller, Jess; Saulsberry, Regor L.

    2003-01-01

    Pilot operated valves (POVs) are used to control the flow of hypergolic propellants monomethylhydrazine (fuel) and nitrogen tetroxide (oxidizer) to the Shuttle orbiter Primary Reaction Control Subsystem (PRCS) thrusters. The POV incorporates a two-stage design: a solenoid-actuated pilot stage, which in turn controls a pressure-actuated main stage. Isolation of propellant supply from the thruster chamber is accomplished in part by a captive polytetrafluoroethylene (PTFE) pilot seal retained inside a Custom 455.1 stainless steel cavity. Extrusion of the pilot seal restricts the flow of fuel around the pilot poppet, thus impeding or preventing the main valve stage from opening. It can also prevent the main stage from staying open with adequate force margin, particularly if there is gas in the main stage actuation cavity. During thruster operation on-orbit, fuel valve pilot seal extrusion is commonly indicated by low or erratic chamber pressure or failure of the thruster to fire upon command (Fail-Off). During ground turnaround, pilot seal extrusion is commonly indicated by slow gaseous nitrogen (GN2) main valve opening times (greater than 38 ms) or slow water main valve opening response times (greater than 33 ms). Poppet lift tests and visual inspection can also detect pilot seal extrusion during ground servicing; however, direct metrology on the pilot seat assembly provides the most quantitative and accurate means of identifying extrusion. Minimizing PRCS fuel valve pilot seal extrusion has become an important issue in the effort to improve PRCS reliability and reduce associated life cycle costs.

  1. Melt rheology and molecular weight degradation of amylopectin during multiple pass extrusion of starch

    SciTech Connect

    Willett, J.L.; Millard, M.M.; Jasberg, B.K.

    1996-12-31

    The degradation of starch during extrusion and the role of specific mechanical energy (SME) in this process have been widely studied for single pass extrusion, Multiple extrusion histories are not uncommon in the plastics industry, but little if any has been reported on their effects on starch. Native waxy maize starch (app. 98% amylopectin) was initially converted to a thermoplastic by twin screw extrusion. This extrudate was equilibrated to either 18% or 23% moisture content, and subsequently re-extruded in a single screw extruder (3:1 compression screw) at 110{degrees}C or 130{degrees}C. Melt viscosity data were calculated using the output-pressure data from the second pass. The melts exhibited shear thinning behavior; the power law index increased with temperature, and slightly with moisture content. Molecular weights of selected second-pass extrudates, as well as the native starch and the first-pass extrudate, were measured by light scattering in dimethyl sulfoxide/water. The initial extrusion pass reduced the molecular weight from 300 million to 50 million. Molecular weight reductions in the second pass increased with increasing SME. A first order expression was shown to fit the MW-SME data with a correlation coefficient of 0.91. Implications of the degradation on extrusion processing of starch and the use of single screw extruders for rheological characterization will be discussed.

  2. Subsurface Aluminum Nitride Formation in Iron-Aluminum Alloys

    NASA Astrophysics Data System (ADS)

    Bott, June H.

    Transformation-induced plasticity (TRIP) steels containing higher amounts of aluminum than conventional steels are ideal for structural automotive parts due to their mechanical properties. However, the aluminum tends to react with any processing environment at high temperatures and therefore presents significant challenges during manufacturing. One such challenge occurs during secondary cooling, reheating, and hot-rolling and is caused by a reaction with nitrogen-rich atmospheres wherein subsurface aluminum nitride forms in addition to internal and external oxides. The nitrides are detrimental to mechanical properties and cause surface cracks. It is important to understand how these nitrides and oxides form and their consequences for the quality of steel products. This study looks at model iron-aluminum (up to 8 wt.% aluminum) alloys and uses confocal laser scanning microscopy, x-ray diffraction, scanning electron microscopy with energy dispersive x-ray spectrometry, and transmission electron microscopy to study the effect of various conditions on the growth and development of these precipitates in a subsurface oxygen-depleted region. By using model alloys and controlling the experimental atmosphere, this study is able to understand some of the more fundamental materials science behind aluminum nitride formation in aluminum-rich iron alloys and the relationship between internal nitride and oxide precipitation and external oxide scale morphology and composition. The iron-aluminum alloys were heated in N2 atmospheres containing oxygen impurities. It was found that nitrides formed when bulk aluminum content was below 8 wt.% when oxygen was sufficiently depleted due to the internal oxidation. In the samples containing 1 wt.% aluminum, the depth of the internal oxide and nitride zones were in agreement with a diffusion-based model. Increasing aluminum content to 3 and 5 wt% had the effects of modifying the surface-oxide scale composition and increasing its continuity

  3. [Microbiological corrosion of aluminum alloys].

    PubMed

    Smirnov, V F; Belov, D V; Sokolova, T N; Kuzina, O V; Kartashov, V R

    2008-01-01

    Biological corrosion of ADO quality aluminum and aluminum-based construction materials (alloys V65, D16, and D16T) was studied. Thirteen microscopic fungus species and six bacterial species proved to be able to attack aluminum and its alloys. It was found that biocorrosion of metals by microscopic fungi and bacteria was mediated by certain exometabolites. Experiments on biocorrosion of the materials by the microscopic fungus Alternaria alternata, the most active biodegrader, demonstrated that the micromycete attack started with the appearance of exudate with pH 8-9 on end faces of the samples. PMID:18669265

  4. Plasma Source Ion Implantation of Aluminum and Aluminum Alloys

    NASA Astrophysics Data System (ADS)

    Walter, Kevin Carl

    Three plasma source ion implantation (PSII) schemes applied to three aluminum systems have been studied. Pure aluminum, and aluminum alloys 7075 (Al-Cu-Mg-Zn) and A390 (Al-17Si-Cu-Fe) were (1) argon ion sputter-cleaned and nitrogen-implanted, (2) nitrogen-implanted without sputter -cleaning, and (3) argon-implanted. Nitrogen implantation was performed with the goal of modifying the surface properties by transformation of the surface to aluminum-nitride. Argon implantation was performed with the goal of modifying the surface properties by inducing radiation damage. All implantation schemes were accomplished using a glow discharge mode of the PSII process. Implanted surfaces were investigated using Auger depth profiling and Transmission Electron Microscopy. The profiles indicated a stoichiometric layer, ~ 0.15 μm thick, of AlN on the nitrogen-implanted samples. Electron microscopy confirmed the complete conversion of the aluminum surface to AlN. Knoop microhardness tests showed an increase in surface hardness, especially at low loads. The improvements were independent of prior sputter-cleaning and were approximately equal for the studied aluminum systems. Pin-on-disk wear tests were conducted using a ruby stylus and isopropanol lubrication. Argon implantation decreased the wear resistance of pure aluminum and 7075. Nitrogen implantation improved the wear rates by a factor of ~10 for pure aluminum and 7075. These improvements were independent of prior sputter-cleaning. The coefficient of friction was not significantly influenced by the implantation schemes. Due to a coarse microstructure, tribological tests of ion-implanted A390 were inconclusive. Corrosion studies performed in a 3.5 wt% NaCl solution (seawater) indicated nitrogen implantation gave pure aluminum improved corrosion resistance. The improvement is due to the complete conversion of the aluminum surface to AlN. Because of pre-existing precipitates, the corrosion properties of 7075 and A390 were not

  5. Traumatic iridial extrusion mimicking a conjunctival melanocytic neoplasm

    PubMed Central

    Zoroquiain, Pablo; Ganimi, Maria SB; Alghamdi, Sarah; Burnier, Julia V; Aldrees, Sultan S; Burnier, Miguel N

    2016-01-01

    Conjunctival melanoma is a rare malignant tumour of the eye. Its diagnosis represents a challenge for general pathologists due to low exposure to ocular biopsies and a broad differential diagnosis. In addition, conjunctival samples are often small and are associated with a high frequency of artefacts due to their processing. Here, we present the first case to date of a traumatic iridial extrusion masquerading as a conjunctival melanocytic neoplasm. An 83-year-old Asian man presented with a conjunctival-pigmented nodule surrounded by an area of diffuse pigmentation. Histopathology revealed in the nodule a well-demarcated lesion composed of spindle shaped melanocytes with thick-walled blood vessels. At higher magnification, the blood vessels were composed of thick walls with collagen fibres in an onion-skin-like arrangement. The histological findings were consistent with extruded iridial tissue. The map biopsies of the flat, pigmented lesion showed melanocytic cell proliferation with dendritic processes restricted to the lamina propria without any epithelial involvement, consistent with ocular melanocytosis. The diagnosis of conjunctival melanocytic lesions is challenging, and non-neoplastic conditions should always be included in the differential diagnosis. Pathologists should correlate clinicopathological findings and be familiar with the normal histology in order to achieve the correct diagnosis. PMID:26913071

  6. Bioavailability enhancement of atovaquone using hot melt extrusion technology.

    PubMed

    Kate, Laxman; Gokarna, Vinod; Borhade, Vivek; Prabhu, Priyanka; Deshpande, Vinita; Pathak, Sulabha; Sharma, Shobhona; Patravale, Vandana

    2016-04-30

    Emerging parasite resistance and poor oral bioavailability of anti-malarials are the two cardinal issues which hinder the clinical success of malaria chemotherapy. Atovaquone-Proguanil is a WHO approved fixed dose combination used to tackle the problem of emerging resistance. However, Atovaquone is a highly lipophilic drug having poor aqueous solubility (less than 0.2 μg/ml) thus reducing its oral bioavailability. The aim of the present investigation was to explore hot melt extrusion (HME) as a solvent-free technique to enhance solubility and oral bioavailability of Atovaquone and to develop an oral dosage form for Atovaquone-Proguanil combination. Solid dispersion of Atovaquone was successfully developed using HME. The solid dispersion was characterized for DSC, FTIR, XRD, SEM, and flow properties. It was filled in size 2 hard gelatin capsules. The formulation showed better release as compared to Malarone® tablets, and 3.2-fold and 4.6-fold higher bioavailability as compared to Malarone® tablets and Atovaquone respectively. The enhanced bioavailability also resulted in 100% anti-malarial activity in murine infection model at 1/8(th) therapeutic dose. Thus the developed methodology shows promising potential to solve the problems associated with Atovaquone therapy, namely its high cost and poor oral bioavailability, resulting in increased therapeutic efficacy of Atovaquone. PMID:26969110

  7. Multilayered ceramic/metal composites by extrusion freeform fabrication

    NASA Astrophysics Data System (ADS)

    Kasichainula, Sridhar

    Metal layers within a laminar ceramic can improve damage tolerance of ceramics by arresting large cracks either by ductile bridging or by crack deflection at the ceramic/metal interface, which will allow engineers to design reliable ceramics for structural applications. At low volume fractions of the metal ductile bridging is not very effective, mainly owing to decreased distance between the crack tip and next ceramic layer. Significant increase in the energy absorption during fracture can come from delamination, but depends on the interfacial fracture resistance. A two-fold increase in energy absorption is realized in the case of glass-ceramic/silver laminates prepared by extrusion freeform fabrication. Interfacial fracture energy for glass-ceramic/silver is found to be 100 J/m2 in comparison to 15 J/m2 for glass-ceramic/SiC, which should explain the sporadic crack deflection in notched four-point bend. For a short beam flexural test shear failure is more favorable in four-point than in three-point bending. In four-point tests, the shear stresses between the outer and inner loading pins can precipitate shear delamination prior to tensile cracking of the layers. Damage modes under low velocity impact tests are similar to four-point bend showing delamination as primary energy dissipation mechanism.

  8. Modeling and Characterization of Texture Evolution in Twist Extrusion

    NASA Astrophysics Data System (ADS)

    Latypov, Marat I.; Lee, Myoung-Gyu; Beygelzimer, Yan; Prilepo, Denis; Gusar, Yuri; Kim, Hyoung Seop

    2016-03-01

    Twist extrusion (TE) is a severe plastic deformation method with a potential for commercialization. Deformation during the TE process is non-uniform and non-monotonic, which is expected to result in significant and non-trivial microstructural changes in metallic materials. In this study, texture evolution during TE of pre-textured copper was investigated. Experimental characterization of textures after various numbers of passes demonstrated that TE can be used for producing uniformly weak textures in pre-textured copper. Crystal plasticity simulations were found to run into the problem known as strain reversal texture. In particular, crystal plasticity simulations predicted the return of initial texture upon strain reversal in the first pass of TE, whereas the experimental texture was not reversed and had components related to simple shear. Grain refinement, imperfect strain reversal, and material asymmetry are proposed to be responsible for the occurrence of strain reversal texture in TE. Effects of the non-random initial texture on the microstructure and texture evolution are also discussed.

  9. Effect of common classes of excipients on extrusion-spheronization.

    PubMed

    Law, M F; Deasy, P B

    1997-01-01

    Different classes of excipients with potential for use in the design of novel pelletized formulations manufactured by extrusion-spheronization were examined using factorial experiments. Among the various silicates examined in a model mix with microcrystalline cellulose and lactose wetted with water, kaolin, talc and Veegum F provided improved plasticity for the formation of spherical pellets. Weak bases such sodium bicarbonate and weak acids such as fumaric acid also aided spheronization. Whereas waxy materials such as hydrogenated castor oil and Precirol ATO5, and wetting agent such as sodium lauryl sulphate improved sphericity, these excipients reduced pellet yield by favouring agglomeration. Other materials promoting unwanted formation of over-size pellets were bentonite, citric acid and tartaric acid. The inclusion of Bentone 27, various hydroxide and carbonate bases, and fumaric acid favoured fines production. Collectively the results showed that within classes of excipients, it was not possible to predict the effect of different materials on pellet yield and sphericity. However, Carr's index and Hausner ratio calculated from density determinations correlated well with sphericity measured by image analysis. PMID:9292440

  10. Traumatic iridial extrusion mimicking a conjunctival melanocytic neoplasm.

    PubMed

    Zoroquiain, Pablo; Ganimi, Maria Sb; Alghamdi, Sarah; Burnier, Julia V; Aldrees, Sultan S; Burnier, Miguel N

    2016-01-01

    Conjunctival melanoma is a rare malignant tumour of the eye. Its diagnosis represents a challenge for general pathologists due to low exposure to ocular biopsies and a broad differential diagnosis. In addition, conjunctival samples are often small and are associated with a high frequency of artefacts due to their processing. Here, we present the first case to date of a traumatic iridial extrusion masquerading as a conjunctival melanocytic neoplasm. An 83-year-old Asian man presented with a conjunctival-pigmented nodule surrounded by an area of diffuse pigmentation. Histopathology revealed in the nodule a well-demarcated lesion composed of spindle shaped melanocytes with thick-walled blood vessels. At higher magnification, the blood vessels were composed of thick walls with collagen fibres in an onion-skin-like arrangement. The histological findings were consistent with extruded iridial tissue. The map biopsies of the flat, pigmented lesion showed melanocytic cell proliferation with dendritic processes restricted to the lamina propria without any epithelial involvement, consistent with ocular melanocytosis. The diagnosis of conjunctival melanocytic lesions is challenging, and non-neoplastic conditions should always be included in the differential diagnosis. Pathologists should correlate clinicopathological findings and be familiar with the normal histology in order to achieve the correct diagnosis. PMID:26913071

  11. Current advances and future perspectives in extrusion-based bioprinting.

    PubMed

    Ozbolat, Ibrahim T; Hospodiuk, Monika

    2016-01-01

    Extrusion-based bioprinting (EBB) is a rapidly growing technology that has made substantial progress during the last decade. It has great versatility in printing various biologics, including cells, tissues, tissue constructs, organ modules and microfluidic devices, in applications from basic research and pharmaceutics to clinics. Despite the great benefits and flexibility in printing a wide range of bioinks, including tissue spheroids, tissue strands, cell pellets, decellularized matrix components, micro-carriers and cell-laden hydrogels, the technology currently faces several limitations and challenges. These include impediments to organ fabrication, the limited resolution of printed features, the need for advanced bioprinting solutions to transition the technology bench to bedside, the necessity of new bioink development for rapid, safe and sustainable delivery of cells in a biomimetically organized microenvironment, and regulatory concerns to transform the technology into a product. This paper, presenting a first-time comprehensive review of EBB, discusses the current advancements in EBB technology and highlights future directions to transform the technology to generate viable end products for tissue engineering and regenerative medicine. PMID:26561931

  12. PREPARATION OF URANIUM-ALUMINUM ALLOYS

    DOEpatents

    Moore, R.H.

    1962-09-01

    A process is given for preparing uranium--aluminum alloys from a solution of uranium halide in an about equimolar molten alkali metal halide-- aluminum halide mixture and excess aluminum. The uranium halide is reduced and the uranium is alloyed with the excess aluminum. The alloy and salt are separated from each other. (AEC)

  13. Evaluation and Characterization of In-Line Annealed Continuous Cast Aluminum Sheet

    SciTech Connect

    Dr Subodh K. Das

    2006-01-17

    This R&D program will develop optimized, energy-efficient thermo-mechanical processing procedures for in-line annealing of continuously cast hot bands of two 5000 series aluminum alloys (5754 and 5052). The implementation of the R&D will result in the production of sheet with improved formability at high levels of productivity consistency and quality. The proposed R&D involves the following efforts: (1) Design and build continuous in-line annealing equipment for plant-scale trials; (2) Carry out plant-scale trials at Commonwealth Aluminum Corp.'s (CAC) plant in Carson; (3) Optimize the processing variables utilizing a metallurgical model for the kinetics of microstructure and texture evolution during thermo-mechanical processing; (4) Determine the effects of processing variables on the microstructure, texture, mechanical properties, and formability of aluminum sheet; (5) Develop design parameters for commercial implementation; and (6) Conduct techno-economic studies of the recommended process equipment to identify impacts on production costs. The research and development is appropriate for the domestic industry as it will result in improved aluminum processing capabilities and thus lead to greater application of aluminum in various industries including the automotive market. A teaming approach is critical to the success of this effort as no single company alone possesses the breadth of technical and financial resources for successfully carrying out the effort. This program will enable more energy efficient aluminum sheet production technology, produce consistent high quality product, and have The proposal addresses the needs of the aluminum industry as stated in the aluminum industry roadmap by developing new and improved aluminum processes utilizing energy efficient techniques. The effort is primarily related to the subsection on Rolling and Extrusion with the R&D to address energy and environmental efficiencies in aluminum manufacturing and will provide

  14. Electrolyte treatment for aluminum reduction

    DOEpatents

    Brown, Craig W.; Brooks, Richard J.; Frizzle, Patrick B.; Juric, Drago D.

    2002-01-01

    A method of treating an electrolyte for use in the electrolytic reduction of alumina to aluminum employing an anode and a cathode, the alumina dissolved in the electrolyte, the treating improving wetting of the cathode with molten aluminum during electrolysis. The method comprises the steps of providing a molten electrolyte comprised of ALF.sub.3 and at least one salt selected from the group consisting of NaF, KF and LiF, and treating the electrolyte by providing therein 0.004 to 0.2 wt. % of a transition metal or transition metal compound for improved wettability of the cathode with molten aluminum during subsequent electrolysis to reduce alumina to aluminum.

  15. Chrome - Free Aluminum Coating System

    NASA Technical Reports Server (NTRS)

    Bailey, John H.; Gugel, Jeffrey D.

    2010-01-01

    This slide presentation concerns the program to qualify a chrome free coating for aluminum. The program was required due to findings by OSHA and EPA, that hexavalent chromium, used to mitigate corrosion in aerospace aluminum alloys, poses hazards for personnel. This qualification consisted of over 4,000 tests. The tests revealed that a move away from Cr+6, required a system rather than individual components and that the maximum corrosion protection required pretreatment, primer and topcoat.

  16. Aluminum laser welding optimization

    NASA Astrophysics Data System (ADS)

    Chmelíčková, Hana; Halenka, Viktor; Lapšanská, Hana; Havelková, Martina

    2007-04-01

    Pulsed Nd:YAG laser with maximal power 150 W is used in our laboratory to cut, drill and weld metal and non-metal thin materials to thickness 2 mm. Welding is realized by fixed processing head or movable fiber one with beam diameter 0,6 mm in focus plane. Welding of stainless and low-carbon steel was tested before and results are publicized and used in practice. Now the goal of our experiment was optimization of process parameters for aluminum that has other physical properties than steels, lower density, higher heat conductivity and surface reflexivity. Pure alumina specimen 0,8 mm and Al-Mg-Si alloy 0,5 mm prepared for butt welds. Problem with surface layer of Al IIO 3 was overcome by sanding and chemical cleaning with grinding paste. Critical parameters for good weld shape are specimen position from beam focus plane, pulse length and energy, pulse frequency and the motion velocity that determines percentage of pulse overlap. Argon as protective gas was used with speed 6 liters per second. Thermal distribution in material can be modeled by numerical simulation. Software tool SYSWELD makes possible to fit laser as surface heat source, define weld geometry, and make meshing of specimen to finite elements and compute heat conduction during process. Color isotherms, vectors, mechanical deformations and others results can be study in post-processing.

  17. Anodized aluminum on LDEF

    NASA Technical Reports Server (NTRS)

    Golden, Johnny L.

    1993-01-01

    A compilation of reported analyses and results obtained for anodized aluminum flown on the Long Duration Exposure Facility (LDEF) was prepared. Chromic acid, sulfuric acid, and dyed sulfuric acid anodized surfaces were exposed to the space environment. The vast majority of the anodized surface on LDEF was chromic acid anodize because of its selection as a thermal control coating for use on the spacecraft primary structure, trays, tray clamps, and space end thermal covers. Reports indicate that the chromic acid anodize was stable in solar absorptance and thermal emittance, but that contamination effects caused increases in absorptance on surfaces exposed to low atomic oxygen fluences. There were some discrepancies, however, in that some chromic acid anodized specimens exhibited significant increases in absorptance. Sulfuric acid anodized surfaces also appeared stable, although very little surface area was available for evaluation. One type of dyed sulfuric acid anodize was assessed as an optical baffle coating and was observed to have improved infrared absorptance characteristics with exposure on LDEF.

  18. Managing aluminum phosphide poisonings

    PubMed Central

    Gurjar, Mohan; Baronia, Arvind K; Azim, Afzal; Sharma, Kalpana

    2011-01-01

    Aluminum phosphide (AlP) is a cheap, effective and commonly used pesticide. However, unfortunately, it is now one of the most common causes of poisoning among agricultural pesticides. It liberates lethal phosphine gas when it comes in contact either with atmospheric moisture or with hydrochloric acid in the stomach. The mechanism of toxicity includes cellular hypoxia due to the effect on mitochondria, inhibition of cytochrome C oxidase and formation of highly reactive hydroxyl radicals. The signs and symptoms are nonspecific and instantaneous. The toxicity of AlP particularly affects the cardiac and vascular tissues, which manifest as profound and refractory hypotension, congestive heart failure and electrocardiographic abnormalities. The diagnosis of AlP usually depends on clinical suspicion or history, but can be made easily by the simple silver nitrate test on gastric content or on breath. Due to no known specific antidote, management remains primarily supportive care. Early arrival, resuscitation, diagnosis, decrease the exposure of poison (by gastric lavage with KMnO4, coconut oil), intensive monitoring and supportive therapy may result in good outcome. Prompt and adequate cardiovascular support is important and core in the management to attain adequate tissue perfusion, oxygenation and physiologic metabolic milieu compatible with life until the tissue poison levels are reduced and spontaneous circulation is restored. In most of the studies, poor prognostic factors were presence of acidosis and shock. The overall outcome improved in the last decade due to better and advanced intensive care management. PMID:21887030

  19. Managing aluminum phosphide poisonings.

    PubMed

    Gurjar, Mohan; Baronia, Arvind K; Azim, Afzal; Sharma, Kalpana

    2011-07-01

    Aluminum phosphide (AlP) is a cheap, effective and commonly used pesticide. However, unfortunately, it is now one of the most common causes of poisoning among agricultural pesticides. It liberates lethal phosphine gas when it comes in contact either with atmospheric moisture or with hydrochloric acid in the stomach. The mechanism of toxicity includes cellular hypoxia due to the effect on mitochondria, inhibition of cytochrome C oxidase and formation of highly reactive hydroxyl radicals. The signs and symptoms are nonspecific and instantaneous. The toxicity of AlP particularly affects the cardiac and vascular tissues, which manifest as profound and refractory hypotension, congestive heart failure and electrocardiographic abnormalities. The diagnosis of AlP usually depends on clinical suspicion or history, but can be made easily by the simple silver nitrate test on gastric content or on breath. Due to no known specific antidote, management remains primarily supportive care. Early arrival, resuscitation, diagnosis, decrease the exposure of poison (by gastric lavage with KMnO(4), coconut oil), intensive monitoring and supportive therapy may result in good outcome. Prompt and adequate cardiovascular support is important and core in the management to attain adequate tissue perfusion, oxygenation and physiologic metabolic milieu compatible with life until the tissue poison levels are reduced and spontaneous circulation is restored. In most of the studies, poor prognostic factors were presence of acidosis and shock. The overall outcome improved in the last decade due to better and advanced intensive care management. PMID:21887030

  20. Acid extrusion is induced by osteoclast attachment to bone. Inhibition by alendronate and calcitonin.

    PubMed Central

    Zimolo, Z; Wesolowski, G; Rodan, G A

    1995-01-01

    Acid extrusion is essential for osteoclast (OC) activity. We examined Na+ and HCO3(-)-independent H+ extrusion in rat- and mouse OCs by measuring intracellular pH (pHi) changes, with the pHi indicator BCECF (biscarboxyethyl-5-(6) carboxyfluorescein) after H+ loading with an ammonium pulse. 90% of OCs attached to glass do not possess HCO3- and Na(+)-independent H(+)-extrusion (rate of pHi recovery = 0.043 +/- 0.007 (SEM) pH U/min, n = 26). In contrast, in OCs attached to bone, the pHi recovery rate is 0.228 +/- 0.011 pHi U/min, n = 25. OCs on bone also possess a NH(4+)-permeable pathway not seen on glass. The bone-induced H+ extrusion was inhibited by salmon calcitonin (10(-8) M, for 2 h), and was not present after pretreating the bone slices with the aminobisphosphonate alendronate (ALN). At ALN levels of 0.22 nmol/mm2 bone, H+ extrusion was virtually absent 12 h after cell seeding (0.004 +/- 0.002 pH U/min) and approximately 50% inhibition was observed at 0.022 pmol ALN/mm2 bone. The Na(+)-independent H+ extrusion was not inhibited by bafilomycin A1 (up to 10(-7) M), although a bafilomycin A1 (10(-8) M)-sensitive H+ pump was present in membrane vesicles isolated from these osteoclasts. These findings indicate that Na(+)-independent acid extrusion is stimulated by osteoclast attachment to bone and is virtually absent when bone is preincubated with ALN, or when osteoclasts are treated with salmon calcitonin. Images PMID:7593614

  1. Terahertz inline wall thickness monitoring system for plastic pipe extrusion

    NASA Astrophysics Data System (ADS)

    Hauck, J.; Stich, D.; Heidemeyer, P.; Bastian, M.; Hochrein, T.

    2014-05-01

    Conventional and commercially available inline wall thickness monitoring systems for pipe extrusion are usually based on ultrasonic or x-ray technology. Disadvantages of ultrasonic systems are the usual need of water as a coupling media and the high damping in thick walled or foamed pipes. For x-ray systems special safety requirements have to be taken into account because of the ionizing radiation. The terahertz (THz) technology offers a novel approach to solve these problems. THz waves have many properties which are suitable for the non-destructive testing of plastics. The absorption of electrical isolators is typically very low and the radiation is non-ionizing in comparison to x-rays. Through the electromagnetic origin of the THz waves they can be used for contact free measurements. Foams show a much lower absorption in contrast to acoustic waves. The developed system uses THz pulses which are generated by stimulating photoconductive switches with femtosecond laser pulses. The time of flight of THz pulses can be determined with a resolution in the magnitude of several ten femtoseconds. Hence the thickness of an object like plastic pipes can be determined with a high accuracy by measuring the time delay between two reflections on materials interfaces e.g. at the pipe's inner and outer surface, similar to the ultrasonic technique. Knowing the refractive index of the sample the absolute layer thickness from the transit time difference can be calculated easily. This method in principle also allows the measurement of multilayer systems and the characterization of foamed pipes.

  2. Terahertz inline wall thickness monitoring system for plastic pipe extrusion

    SciTech Connect

    Hauck, J. E-mail: d.stich@skz.de E-mail: m.bastian@skz.de Stich, D. E-mail: d.stich@skz.de E-mail: m.bastian@skz.de Heidemeyer, P. E-mail: d.stich@skz.de E-mail: m.bastian@skz.de Bastian, M. E-mail: d.stich@skz.de E-mail: m.bastian@skz.de Hochrein, T. E-mail: d.stich@skz.de E-mail: m.bastian@skz.de

    2014-05-15

    Conventional and commercially available inline wall thickness monitoring systems for pipe extrusion are usually based on ultrasonic or x-ray technology. Disadvantages of ultrasonic systems are the usual need of water as a coupling media and the high damping in thick walled or foamed pipes. For x-ray systems special safety requirements have to be taken into account because of the ionizing radiation. The terahertz (THz) technology offers a novel approach to solve these problems. THz waves have many properties which are suitable for the non-destructive testing of plastics. The absorption of electrical isolators is typically very low and the radiation is non-ionizing in comparison to x-rays. Through the electromagnetic origin of the THz waves they can be used for contact free measurements. Foams show a much lower absorption in contrast to acoustic waves. The developed system uses THz pulses which are generated by stimulating photoconductive switches with femtosecond laser pulses. The time of flight of THz pulses can be determined with a resolution in the magnitude of several ten femtoseconds. Hence the thickness of an object like plastic pipes can be determined with a high accuracy by measuring the time delay between two reflections on materials interfaces e.g. at the pipe's inner and outer surface, similar to the ultrasonic technique. Knowing the refractive index of the sample the absolute layer thickness from the transit time difference can be calculated easily. This method in principle also allows the measurement of multilayer systems and the characterization of foamed pipes.

  3. Development and standardization of sorghum pasta using extrusion technology.

    PubMed

    Benhur, Dayakar Rao; Bhargavi, G; Kalpana, K; Vishala, A D; Ganapathy, K N; Patil, J V

    2015-10-01

    Extrusion cooking is a unique method for preparing pasta, which is generally produced from durum wheat semolina. However, preparation of pasta from sorghum is not practiced in India. Therefore, the present study was undertaken to develop and standardize pasta from sorghum cultivar, M35-1 and wheat semolina of 0.1 mm particle size. Sorghum and wheat semolina in different proportions (T1;S:W-50:50,T2;S:W-60:40,T3;S:W-70:30,T4; S:W-80:20, T5; S -100) were mixed with lukewarm water (40 °C) in the cold extruder for 30 min and passed through the extruder with a screw speed of 80 rpm and at a temperature of 55° to obtain pasta of diameter (0.6 mm) and length (1.4 mm). The extruded pasta was dried at 70 °C in a tray drier for 8 h, cooled and stored in polyethylene bags at room temperature. The pasta was subjected to physico-chemical analysis such as length, diameter, bulk density, water absorption, cooking time, cooking loss, moisture, water activity, alcoholic acidity, amylase, carbohydrates, fat, protein, fibre and ash using standard methods. Organoleptic characteristics such as color and appearance, texture, taste, flavor and overall acceptability, stickiness, bulkiness and firmness were evaluated at laboratory level by a panel of semi trained judges using 5 point hedonic rating scale. Among the various blends studied, the sorghum and wheat semolina with a combination of 50:50 (T1) and 60:40 (T2) and 70:30 (T3) were more acceptable than others. Well acceptable sorghum pasta can be developed from sorghum and wheat, thereby improving its nutritional composition. PMID:26396437

  4. Commonwealth Aluminum: Manufacturer Conducts Plant-Wide Energy Assessments at Two Aluminum Sheet Production Operations;

    SciTech Connect

    Not Available

    2006-04-01

    DOE Industrial Technologies Program case study describes the savings possible if Commonwealth Aluminum (now Aleris Rolled Products) makes improvements noted in energy assessments at two aluminum mills.

  5. Commonwealth Aluminum: Manufacturer Conducts Plant-Wide Energy Assessments at Two Aluminum Sheet Production Operations

    SciTech Connect

    2006-04-01

    DOE Industrial Technologies Program case study describes the savings possible if Commonwealth Aluminum (now Aleris Rolled Products) makes improvements noted in energy assessments at two aluminum mills.

  6. Lateral extrusion in the Eastern Alps revisited: Refining the model by thermochronological, sedimentary, and seismic data

    NASA Astrophysics Data System (ADS)

    WöLfler, Andreas; Kurz, Walter; Fritz, Harald; Stüwe, Kurt

    2011-08-01

    This study comprises a reassessment of the classical model of lateral extrusion in the Eastern Alps by using recently published geochronological data, sedimentary ages from intramontane basins, ages and distribution of magmatic rocks, and information from seismic profiles. Extrusion-related faulting continuously propagated from the western toward the central eastern part of the Eastern Alps during Oligocene to Middle Miocene times. This is confined by oblique convergence between the Adriatic and European plates. During Middle Miocene times, extrusion became not only lateral in terms of parallel to the trend of the Eastern Alps, but was characterized by a displacement vector at a high angle to the strike of the orogen. This resulted in the exhumation of the Schladming and Pohorje blocks that were exhumed within extensional bridges at the northern and southern terminations of the Pöls-Lavanttal fault system, respectively. From Middle Miocene to recent times, extrusion was controlled by overall extension between the Dinaric and Carpathian subduction zones. The influence of north directed compression triggered by the northward moving Adriatic plate diminished, and the influence of the retreating Carpathian subduction zone increased. This gave rise to Miocene volcanism that is exclusively found east of the Dinaric subduction zone. We therefore consider that lateral extrusion in the Eastern Alps can be subdivided into distinct tectonic phases, with less pronounced eastward extension-related displacement between Late Oligocene and Middle Miocene times. As soon as the Eastern Alps passed the Dinaric subduction zone, the entire domain became highly extensive.

  7. Intrusion-extrusion spring performance of -COK-14 zeolite enhanced by structural changes.

    PubMed

    Kirschhock, Christine E A; De Prins, Michiel; Verheijen, Elke; Ryzhikov, Andrey; Jean Daou, T; Nouali, Habiba; Taulelle, Francis; Martens, Johan A; Patarin, Joël

    2016-07-28

    -COK-14 zeolite, the variant of COK-14 (OKO topology) with a systematically interrupted framework, exhibits unusual behaviour in high pressure intrusion-extrusion cycles of 20 M LiCl solution. After the first cycle with deviating behaviour and partially irreversible intrusion, subsequent cycles show stable reversible behaviour. The system behaves like a spring with unique progressive intrusion in the range of 10-120 MPa followed by enhanced uptake before saturation. While the intrusion-extrusion cycling leads to fragmented crystals, powder diffraction reveals high crystallinity of the fragments. Based on the detailed characterisation of the zeolite samples with XRD, Rietveld refinement, N2 adsorption, TGA and (29)Si MAS NMR before and after intrusion-extrusion experiments, a model of the structure of the intruded -COK-14 samples is proposed. Intrusion-extrusion of LiCl solution systematically breaks the most strained bonds in the structure which results in a new framework connectivity with enhanced stability, which persists during the harsh intrusion-extrusion conditions. PMID:27346703

  8. Testing the model of oblique transpression with oblique extrusion in two natural cases: Steps and consequences

    NASA Astrophysics Data System (ADS)

    Fernández, Carlos; Czeck, Dyanna M.; Díaz-Azpiroz, Manuel

    2013-09-01

    Kinematic models of various types of transpression have been used to explain fabric features and strain in many natural deformation studies. Here, a mathematical model that encompasses all monoclinic and triclinic transpressional deformations including triclinic deformation with inclined simple shear (ϕ) and/or inclined extrusion orientations (υ) can be tested using a step-by-step approach with available field evidence. Two cases are presented. The first case from the Wabigoon-Quetico boundary in the Archean Superior Province utilizes both fabric orientation and quantified strain data. The best fit of the field evidence to the model indicates that deformation likely took place along subvertical shear zones via transpression with subhorizontal simple shear (ϕ = 0-20°) and variable inclined extrusion direction (extrusion can be either east or west and υ typically indicates extrusion orientations between 0 and 50° from vertical). The second case of the South Iberian shear zone has fabric orientation data, but no quantifiable strain possibilities. The best fit of the field evidence to the model indicates that deformation likely took place along a moderately inclined shear zone via transpression with subhorizontal simple shear (ϕ = 0-20°) and variable inclined extrusion direction (υ values between 0° and 80° from the true dip of the shear zone). Using this protocol in other examples of natural deformation will allow further constraints to be applied to kinematic models.

  9. Analysis of the flow imbalance on the profile shape during the extrusion of thin magnesium sheets

    SciTech Connect

    Gall, Sven; Müller, Sören; Reimers, Walter

    2013-12-16

    The extrusion process facilitates the production of magnesium sheets featuring a very thin thickness as well as excellent surface properties by using a single process step only. However, the extrusion of the magnesium sheets applying not optimized process parameters, e.g. low billet temperature or/ and poorly deformable magnesium alloy, produce pronounced buckling and waving of the extruded sheets as well as a variation of accuracy in profile shape along the cross section. The present investigation focuses on the FEM-simulation of the extrusion of magnesium sheets in order to clarify the origin of the mentioned effects. The simulations identify the flow imbalance during extrusion as the main critical factor. Due to the flow imbalance after passing the die a large compression stress zone is formed causing the buckling and waving of the thin sheets. Furthermore, the simulations of the magnesium sheet extrusion reveal that the interaction of the material flow gradients along the width and along the thickness direction near the die orifice lead to the variation of the accuracy in profile shape.

  10. Comparison of nixtamalization and extrusion processes for a reduction in aflatoxin content.

    PubMed

    Elias-Orozco, R; Castellanos-Nava, A; Gaytán-Martínez, M; Figueroa-Cárdenas, J D; Loarca-Piña, G

    2002-09-01

    Traditional nixtamalization and an extrusion method for making the dough (masa) for corn tortillas that requires using lime and hydrogen peroxide were evaluated for the detoxification of aflatoxins. The traditional nixtamalization process reduced levels of aflatoxin B(1) (AFB(1)) by 94%, aflatoxin M(1) (AFM(1)) by 90% and aflatoxin B(1)-8,9-dihydrodiol (AFB(1)-dihydrodiol) by 93%. The extrusion process reduced levels of AFB(1) by 46%, AFM(1) by 20% and AFB(1)-dihydrodiol by 53%. Extrusion treatments with 0, 0.3 and 0.5% lime reduced AFB(1) levels by 46, 74 and 85%, respectively. The inactivation of AFB(1), AFM(1) and AFB(1)-dihydrodiol in the extrusion process using lime together with hydrogen peroxide showed higher elimination of AFB(1) than treatments with lime or hydrogen peroxide alone. The extrusion process with 0.3% lime and 1.5% hydrogen peroxide was the most effective process to detoxify aflatoxins in corn tortillas, but a high level of those reagents negatively affected the taste and aroma of the corn tortilla as compared with tortillas elaborated by the traditional nixtamalization process. PMID:12396399

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

    NASA Technical Reports Server (NTRS)

    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.

  12. First principles pseudopotential calculations on aluminum and aluminum alloys

    SciTech Connect

    Davenport, J.W.; Chetty, N.; Marr, R.B.; Narasimhan, S.; Pasciak, J.E.; Peierls, R.F.; Weinert, M.; Rahman, T.S.

    1994-12-31

    Recent advances in computational techniques have led to the possibility of performing first principles calculations of the energetics of alloy formation on systems involving several hundred atoms. This includes impurity concentrations in the 1% range as well as realistic models of disordered materials (including liquids), vacancies, and grain boundaries. The new techniques involve the use of soft, fully nonlocal pseudopotentials, iterative diagonalization, and parallel computing algorithms. This approach has been pioneered by Car and Parrinello. Here the authors give a review of recent results using parallel and serial algorithms by their group on metallic systems including liquid aluminum and liquid sodium, and also new results on vacancies in aluminum and on aluminum-magnesium alloys.

  13. Weld Repair of Thin Aluminum Sheet

    NASA Technical Reports Server (NTRS)

    Beuyukian, C. S.; Mitchell, M. J.

    1986-01-01

    Weld repairing of thin aluminum sheets now possible, using niobium shield and copper heat sinks. Refractory niobium shield protects aluminum adjacent to hole, while copper heat sinks help conduct heat away from repair site. Technique limits tungsten/inert-gas (TIG) welding bombardment zone to melt area, leaving surrounding areas around weld unaffected. Used successfully to repair aluminum cold plates on Space Shuttle, Commercial applications, especially in sealing fractures, dents, and holes in thin aluminum face sheets or clad brazing sheet in cold plates, heat exchangers, coolers, and Solar panels. While particularly suited to thin aluminum sheet, this process also used in thicker aluminum material to prevent surface damage near weld area.

  14. Scaleable Clean Aluminum Melting Systems

    SciTech Connect

    Han, Q.; Das, S.K.

    2008-02-15

    The project entitled 'Scaleable Clean Aluminum Melting Systems' was a Cooperative Research and Development Agreements (CRADAs) between Oak Ridge National Laboratory (ORNL) and Secat Inc. The three-year project was initially funded for the first year and was then canceled due to funding cuts at the DOE headquarters. The limited funds allowed the research team to visit industrial sites and investigate the status of using immersion heaters for aluminum melting applications. Primary concepts were proposed on the design of furnaces using immersion heaters for melting. The proposed project can continue if the funding agency resumes the funds to this research. The objective of this project was to develop and demonstrate integrated, retrofitable technologies for clean melting systems for aluminum in both the Metal Casting and integrated aluminum processing industries. The scope focused on immersion heating coupled with metal circulation systems that provide significant opportunity for energy savings as well as reduction of melt loss in the form of dross. The project aimed at the development and integration of technologies that would enable significant reduction in the energy consumption and environmental impacts of melting aluminum through substitution of immersion heating for the conventional radiant burner methods used in reverberatory furnaces. Specifically, the program would couple heater improvements with furnace modeling that would enable cost-effective retrofits to a range of existing furnace sizes, reducing the economic barrier to application.

  15. Enhancement and improvement of the mechanical properties of aluminum extruded products by mathematical analysis and simulation process

    NASA Astrophysics Data System (ADS)

    Magid, Hani Mizhir; Sulaiman, S.; Ariffin, M. K. A.; Baharudin, B. T. H. T.

    2015-05-01

    This paper investigates a technique for solving the problems of the aluminum extrusion process, and improving the mechanical properties of the products produced by this method through a smart design, simulation and Mathematical Analysis by using F.E.M. For this purpose, the general F.E.A. Software ABAQUS was used to set up the finite element model of the warm aluminum extrusion in two dimensions (3D). Also, an iterative procedure was carried out using MATLAB at each iteration. The model was formulated as a nonlinear model. The inputs to this model were: the product geometry and its materials specifications such as density, rigidity, elasticity, thermal conductivity, and the required analytical steps. An axisymmetrical (3D) geometric model of the tooling and billet was constructed for the analysis. Data obtained from the F.E model included die-work piece contact pressure, effective stress and strain and material deformation velocity. The correlation between the calculated and collected data from (FEA) was established in this research. Then the billet and die stresses, temperature and the ram speed that closely matched with the strain rates for the desired quality were obtained.

  16. Seismic wave propagation through an extrusive basalt sequence

    NASA Astrophysics Data System (ADS)

    Sanford, Oliver; Hobbs, Richard; Brown, Richard; Schofield, Nick

    2016-04-01

    Layers of basalt flows within sedimentary successions (e.g. in the Faeroe-Shetland Basin) cause complex scattering and attenuation of seismic waves during seismic exploration surveys. Extrusive basaltic sequences are highly heterogeneous and contain strong impedance contrasts between higher velocity crystalline flow cores (˜6 km s‑1) and the lower velocity fragmented and weathered flow crusts (3-4 km s‑1). Typically, the refracted wave from the basaltic layer is used to build a velocity model by tomography. This velocity model is then used to aid processing of the reflection data where direct determination of velocity is ambiguous, or as a starting point for full waveform inversion, for example. The model may also be used as part of assessing drilling risk of potential wells, as it is believed to constrain the total thickness of the sequence. In heterogeneous media, where the scatter size is of the order of the seismic wavelength or larger, scattering preferentially traps the seismic energy in the low velocity regions. This causes a build-up of energy that is guided along the low velocity layers. This has implications for the interpretation of the observed first arrival of the seismic wave, which may be a biased towards the low velocity regions. This will then lead to an underestimate of the velocity structure and hence the thickness of the basalt, with implications for the drilling of wells hoping to penetrate through the base of the basalts in search of hydrocarbons. Using 2-D acoustic finite difference modelling of the guided wave through a simple layered basalt sequence, we consider the relative importance of different parameters of the basalt on the seismic energy propagating through the layers. These include the proportion of high to low velocity material, the number of layers, their thickness and the roughness of the interfaces between the layers. We observe a non-linear relationship between the ratio of high to low velocity layers and the apparent

  17. [Effect of the extrusion process on the functional characteristics and protein quality of quinua (Chenopodium quinoa, Willd)].

    PubMed

    Romero, A; Bacigalupo, A; Bressani, R

    1985-03-01

    In order to have available a human food of high nutritive value, and conscious of the protein quality of the quinua, as well as its carbohydrate, vitamin and mineral content, its behavior during the extrusion process was tested in the present study. To eliminate saponins, a simple method was developed which consisted of washing the seeds through an aluminum container, using a wooden stirrer. Seven treatments were studied: washed quinua, washed and cooked quinua, washed and expanded quinua No. 1 and No. 2, and washed and texturized quinua No. 1 and No. 2; casein was used as control. Biological evaluation trials were carried out in Holtzman rats, following the PER method. To detect the possible effects of the processed quinua on the experimental animals, hematological as well as histopathological studies of the vital organs were performed. A maximum PER of 2.43 was obtained for the texturized quinua, 2.16 for the expanded quinua, 2.6 for the cooked quinua, while the casein control yielded a PER of 3.00. The physico-chemical characteristics of the quinua flour were determined, as well as those of the expanded and texturized products. The product obtained was subjected to an organoleptic trial and it can be stated that the results obtained were satisfactory. The product can be consumed directly without major modifications and has an acceptable flavor. The nutritive value of quinua was not impaired; it compared favorably with the best diets recommended for the population, especially of those with a lower income. The results obtained in the present study suggest the possibility of increasing the nutritional value of the product, as well as its acceptability. PMID:3834873

  18. Effects of extrusion cooking on the chemical composition and functional properties of dry common bean powders.

    PubMed

    Ai, Yongfeng; Cichy, Karen A; Harte, Janice B; Kelly, James D; Ng, Perry K W

    2016-11-15

    The impact of extrusion cooking on the chemical composition and functional properties of bean powders from four common bean varieties was investigated. The raw bean powders were extruded under eight different conditions, and the extrudates were then dried and ground (particle size⩽0.5mm). Compared with corresponding non-extruded (raw) bean powders (particle size⩽0.5mm), the extrusion treatments did not substantially change the protein and starch contents of the bean powders and showed inconsistent effects on the sucrose, raffinose and stachyose contents. The extrusion cooking did cause complete starch gelatinization and protein denaturation of the bean powders and thus changed their pasting properties and solvent-retention capacities. The starch digestibilities of the cooked non-extruded and cooked extruded bean powders were comparable. The extruded bean powders displayed functional properties similar to those of two commercial bean powders. PMID:27283664

  19. A multivariate analysis of the effects of multiple extrusion cycles on high density polyethylene bottle resin

    SciTech Connect

    Zahavich, A.

    1995-10-01

    The recycling of post consumer (PCR) high density polyethylene (HDPE) blow molding resins has increased dramatically over the past 5 years. The focus of research for this product has been on specific performance and processing properties such as tensile or melt strength. Little work has been done on studying the entire range of properties as a whole, particularly in the area of multiple extrusions. This paper describes a designed experiment study where multivariate statistical techniques were used to compare 2 HDPE and 2 HDPE PCR materials, in terms of changes in a number of properties with exposure to multiple extrusions. Virgin homopolymer and copolymer resins and PCR, mixed color bottle and natural, were passed through 4 extrusion cycles. Viscosity, swell, melt strength, crystallinity, polydispersity and ESCR properties were studied using principal component analysis.

  20. Thermoplastic starch/polyester films: effects of extrusion process and poly (lactic acid) addition.

    PubMed

    Shirai, Marianne Ayumi; Olivato, Juliana Bonametti; Garcia, Patrícia Salomão; Müller, Carmen Maria Olivera; Grossmann, Maria Victória Eiras; Yamashita, Fabio

    2013-10-01

    Biodegradable films were produced using the blown extrusion method from blends that contained cassava thermoplastic starch (TPS), poly(butylene adipate-co-terephthalate) (PBAT) and poly(lactic acid) (PLA) with two different extrusion processes. The choice of extrusion process did not have a significant effect on the mechanical properties, water vapor permeability (WVP) or viscoelasticity of the films, but the addition of PLA decreased the elongation, blow-up ratio (BUR) and opacity and increased the elastic modulus, tensile strength and viscoelastic parameters of the films. The films with 20% PLA exhibited a lower WVP due to the hydrophobic nature of this polymer. Morphological analyses revealed the incompatibility between the polymers used. PMID:23910321

  1. Adaptation of in-line ultrasonic velocimetry to melt flow measurement in polymer extrusion

    NASA Astrophysics Data System (ADS)

    Putz, V.; Burzic, I.; Miethlinger, J.; Maier, F.; Zagar, B. G.

    2013-10-01

    Pulsed wave velocimetry (PWV) is an ultrasonic technique for measuring velocity profiles in flowing liquids. In capillaries, PWV requires using ultrasound transducers with high center frequencies and a large bandwidth. This type of transducer is restricted to operating temperatures below 50 °C. However, in polymer extrusion, velocity profiles of flowing liquids with temperatures up to 250 °C are of interest. This contribution describes the development of a new ultrasonic measurement tool, which is fully integrated in a heated capillary die. It enables long-time measurement of the extrudate using the buffer rod technique and active cooling. The developed prototype was successfully validated in an extrusion experiment: the velocity profile of glass-fiber-filled polypropylene was measured immediately after extrusion in a capillary die.

  2. Potassium-dependent sodium extrusion by cells of Porphyra perforata, a red marine alga.

    PubMed

    EPPLEY, R W

    1958-11-20

    Potassium-free artificial sea water causes a loss of cell potassium and a gain of cell sodium in Porphyra perforata, which is not attributable to an inhibition of respiration. On adding KCl or RbCl to such low potassium, high sodium tissues, net accumulation of potassium or rubidium takes place, accompanied by net extrusion of sodium. Rates of potassium or rubidium accumulation and sodium extrusion are proportional to the amount of KCl or RbCl added only at low concentrations. Saturation of rates is evident at KCl or RbCl concentrations above 20-30 mM, suggesting the role of an ion carrier mechanism of transport. Evidence for and against mutually dependent sodium extrusion and potassium or rubidium accumulation is discussed. PMID:13587912

  3. A novel optical technique to characterize fiberization of textured vegetable proteins under high-moisture extrusion

    NASA Astrophysics Data System (ADS)

    Yao, Gang; Liu, Keshun; Hsieh, Fu-Hung

    2004-11-01

    There have been great interests in using twin-screw extruders under high moisture conditions to produce textured vegetable proteins. Unlike the low moisture extrusion counterpart, a product extruded under high moisture can have well-defined fiber orientation and bears a strong resemblance to muscle meat. The textural properties of such extruded products are important for consumer acceptance. In this study, we developed a novel fluorescence polarization based technique that measures the fiber formation of extruded protein products. The experimental results using our new technique showed good agreements with results obtained from visual inspection and digital imaging of the dissected samples. The new technique provides an in vivo and noninvasive approach to characterize the fiber formation of textured vegetable proteins under high moisture extrusion. It has a potential to be used as a real time monitoring tool in food extrusion studies.

  4. Two-sided friction stir riveting by extrusion: A process for joining dissimilar materials

    DOE PAGESBeta

    Evans, William T.; Cox, Chase D.; Strauss, Alvin M.; Cook, George E.; Gibson, Brian T.

    2016-06-25

    Two-sided friction stir riveting (FSR) by extrusion is an innovative process developed to rapidly, efficiently, and securely join dissimilar materials. This process extends a previously developed one sided friction stir extrusion process to create a strong and robust joint by producing a continuous, rivet-like structure through a preformed hole in one of the materials with a simultaneous, two-sided friction stir spot weld. The two-sided FSR by extrusion process securely joins the dissimilar materials together and effectively locks them in place without the use of any separate materials or fasteners. Lastly, in this paper we demonstrate the process by joining aluminummore » to steel and illustrate its potential application to automotive and aerospace manufacturing processes.« less

  5. Starch sodium dodecenyl succinate prepared by one-step extrusion and its properties.

    PubMed

    Tian, Yaoqi; Zhang, Xiwen; Sun, Binhua; Jin, Zhengyu; Wu, Shengjun

    2015-11-20

    One-step extrusion was developed to prepare starch sodium dodecenyl succinate (SSDS). Effects of screwing speed, reaction temperature, moisture content, sodium hydroxide amount (as catalyst), and dodecenly succinic anhydride (DDSA) amount on the degree of substitution (DS) were investigated. Optimum conditions were determined and found to be as follows: screwing speed, 110rpm; temperature, 120°C; moisture content, 30%; sodium hydroxide amount, 0.5%; DDSA amount, 3%. Under these conditions, the DS of SSDS was 0.014%, and the reaction efficiency was 78%. The structure of SSDS prepared by one-step extrusion was partially characterised. Infrared absorption spectra showed peaks of ester bond and carbonyl group at 1707 and 1564cm(-1), respectively, indicating that dodecenyl succinic groups were introduced into starch molecule backbone by esterification agent. X-ray diffraction analysis showed that compared with native starch, the particle morphology of SSDS prepared by extrusion became irregular, and its crystallinity was partially destroyed. PMID:26344259

  6. PREPARATION OF DIBASIC ALUMINUM NITRATE

    DOEpatents

    Gresky, A.T.; Nurmi, E.O.; Foster, D.L.; Wischow, R.P.; Savolainen, J.E.

    1960-04-01

    A method is given for the preparation and recovery of basic aluminum nltrates having an OH: Al ratio of at least two, comprising two steps. First, metallic aluminum is dissolved in aqueous Al(NO/sub 3/)/sub 3/, in the presence of a small quantity of elemental or ionic mercury, to increase its Al: NO/sub 3/ ratio into the range 1 to 1.2. The resulting aqueous solution is then added to an excess of a special organic solvent, typically a mixture of five parts methanol and six parts diethyl ether, whereupon the basic aluminum nitrate, e.g. Al/sub 6/(OH)/sub 13/-(NO/sub 3/)/sub 5/, recoverably precipitates.

  7. Rechargeable Aluminum-Ion Batteries

    SciTech Connect

    Paranthaman, Mariappan Parans; Liu, Hansan; Sun, Xiao-Guang; Dai, Sheng; Brown, Gilbert M

    2015-01-01

    This chapter reports on the development of rechargeable aluminum-ion batteries. A possible concept of rechargeable aluminum/aluminum-ion battery based on low-cost, earth-abundant Al anode, ionic liquid EMImCl:AlCl3 (1-ethyl-3-methyl imidazolium chloroaluminate) electrolytes and MnO2 cathode has been proposed. Al anode has been reported to show good reversibility in acid melts. However, due to the problems in demonstrating the reversibility in cathodes, alternate battery cathodes and battery concepts have also been presented. New ionic liquid electrolytes for reversible Al dissolution and deposition are needed in the future for replacing corrosive EMImCl:AlCl3 electrolytes.

  8. Profile extrusion of wood plastic cellular composites and formulation evaluation using compression molding

    NASA Astrophysics Data System (ADS)

    Islam, Mohammad Rubyet

    Wood Plastic Composites (WPCs) have experienced a healthy growth during the last decade. However, improvement in properties is necessary to increase their utility for structural applications. The toughness of WPCs can be improved by creating a fine cellular structure while reducing the density. Extrusion processing is one of the most economical methods for profile formation. For our study, rectangular profiles were extruded using a twin-screw extrusion system with different grades of HDPE and with varying wood fibre and lubricant contents together with maleated polyethylene (MAPE) coupling agent to investigate their effects on WPC processing and mechanical properties. Work has been done to redesign the extrusion system setup to achieve smoother and stronger profiles. A guiding shaper, submerged in the water, has been designed to guide the material directly through water immediately after exiting the die; instead of passing it through a water cooled vacuum calibrator and then through water. In this way a skin was formed quickly that facilitated the production of smoother profiles. Later on chemical blowing agent (CBA) was used to generate cellular structure in the profile by the same extrusion system. CBA contents die temperatures, drawdown ratios (DDR) and wood fibre contents (WF) were varied for optimization of mechanical properties and morphology. Cell morphology and fibre alignment was characterized by a scanning electron microscope (SEM). A new compression molding system was developed to help in quick evaluation of different material formulations. This system forces the materials to flow in one direction to achieve higher net alignment of fibres during sample preparation, which is the case during profile extrusion. Operation parameters were optimized and improvements in WPC properties were observed compared to samples prepared by conventional hot press and profile extrusion.

  9. Recycling of aluminum salt cake

    SciTech Connect

    Jody, B.J.; Daniels, E.J.; Bonsignore, P.V.; Karvelas, D.E.

    1991-12-01

    The secondary aluminum industry generates more than 110 {times} 10{sup 3} tons of salt-cake waste every year. This waste stream contains about 3--5% aluminum, 15--30% aluminum oxide, 30--40% sodium chloride, and 20--30% potassium chloride. As much as 50% of the content of this waste is combined salt (sodium and potassium chlorides). Salt-cake waste is currently disposed of in conventional landfills. In addition, over 50 {times} 10{sup 3} tons of black dross that is not economical to reprocess a rotary furnace for aluminum recovery ends up in landfills. The composition of the dross is similar to that of salt cake, except that it contains higher concentrations of aluminum (up to 20%) and correspondingly lower amounts of salts. Because of the high solubility of the salts in water, these residues, when put in landfills, represent a potential source of pollution to surface-water and groundwater supplies. The increasing number of environmental regulations on the generation and disposal of industrial wastes are likely to restrict the disposal of these salt-containing wastes in conventional landfills. Processes exist that employ the dissolution and recovery of the salts from the waste stream. These wet-processing methods are economical only when the aluminum concentration in that waste exceeds about 10%. Argonne National Laboratory (ANL) conducted a study in which existing technologies were reviewed and new concepts that are potentially more cost-effective than existing processes were developed and evaluated. These include freeze crystallization, solvent/antisolvent extraction, common-ion effect, high-pressure/high-temperature process, and capillary-effect systems. This paper presents some of the technical and economic results of the aforementioned ANL study.

  10. Aluminum-air battery crystallizer

    SciTech Connect

    Maimoni, A.

    1987-01-23

    A prototype crystallizer system for the aluminum-air battery operated reliably through simulated startup and shutdown cycles and met its design objectives. The crystallizer system allows for crystallization and removal of the aluminium hydroxide reaction product; it is required to allow steady-state and long-term operation of the aluminum-air battery. The system has to minimize volume and maintain low turbulence and shear to minimize secondary nucleation and energy consumption while enhancing agglomeration. A lamella crystallizer satisfies system constraints.

  11. Aluminum-carbon composite electrode

    DOEpatents

    Farahmandi, C.J.; Dispennette, J.M.

    1998-07-07

    A high performance double layer capacitor having an electric double layer formed in the interface between activated carbon and an electrolyte is disclosed. The high performance double layer capacitor includes a pair of aluminum impregnated carbon composite electrodes having an evenly distributed and continuous path of aluminum impregnated within an activated carbon fiber preform saturated with a high performance electrolytic solution. The high performance double layer capacitor is capable of delivering at least 5 Wh/kg of useful energy at power ratings of at least 600 W/kg. 3 figs.

  12. Aluminum-carbon composite electrode

    DOEpatents

    Farahmandi, C. Joseph; Dispennette, John M.

    1998-07-07

    A high performance double layer capacitor having an electric double layer formed in the interface between activated carbon and an electrolyte is disclosed. The high performance double layer capacitor includes a pair of aluminum impregnated carbon composite electrodes having an evenly distributed and continuous path of aluminum impregnated within an activated carbon fiber preform saturated with a high performance electrolytic solution. The high performance double layer capacitor is capable of delivering at least 5 Wh/kg of useful energy at power ratings of at least 600 W/kg.

  13. Hermetically sealed aluminum electrolytic capacitor

    NASA Technical Reports Server (NTRS)

    Alwitt, Robert S.; Liu, Yanming; Elias, William

    1995-01-01

    Aluminum electrolytic capacitors are presently not allowed on NASA missions because they outgas water and organic vapors, as well as H2. As a consequence, much larger and heavier packages of tantalum capacitors are used. A hermetically sealed aluminum capacitor has been developed under NASA-MSFC SBIR contracts. This capacitor contains a nongassing electrolyte that was developed for this application so internal pressure would remain low. Capacitors rated at 250 to 540 V have been operated under full load for thousands of hours at 85 and 105 C with good electrical performance and low internal pressure. Electrolyte chemistry and seal engineering concepts will be discussed.

  14. Advances in aluminum casting technology

    SciTech Connect

    Tiryakioglu, M.; Campbell, J.

    1998-01-01

    This symposium focuses on the improvements of aluminum casting quality and reliability through a better understanding of processes and process variables, and explores the latest innovations in casting-process design that allow increasing use of the castings to replace complex assemblies and heavy steel and cast-iron components in aerospace and automotive applications. Presented are 35 papers by international experts in the various aspects of the subject. The contents include: Semisolid casting; Computer-aided designing of molds and castings; Casting-process modeling; Aluminum-matrix composite castings; HIPing of castings; Progress in the US car project; Die casting and die design; and Solidification and properties.

  15. Dental Extrusion with Orthodontic Miniscrew Anchorage: A Case Report Describing a Modified Method

    PubMed Central

    Horliana, Ricardo Fidos; Horliana, Anna Carolina Ratto Tempestini; Wuo, Alexandre do Vale; Perez, Flávio Eduardo Guillin; Abrão, Jorge

    2015-01-01

    In recent years, the skeletal anchorage through miniscrews has expanded the treatment options in orthodontics (Yamaguchi et al., 2012). We hereby present a modified method for tooth extrusion for cases where crown-lengthening surgery is contraindicated for aesthetic reasons. This modified method uses three orthodontic appliances: a mini-implant, an orthodontic wire, and a bracket. The aim of this case report was to increase the length of the clinical crown of a fractured tooth (tooth 23) by means of an orthodontic extrusion with the modified method of Roth and Diedrich. PMID:25713739

  16. EFFECT OF TEMPERATURE ON TEXTURE EVOLUTION IN TANTALUM DURING DYNAMIC-EXTRUSION

    SciTech Connect

    Trujillo, Carl P.; Escobedo-Diaza, Juan P.; Gray III, George T.; Cerreta, Ellen K.; Martinez, Daniel T.

    2012-06-20

    Motivation of this project is: (1) Build a furnace as a cross section of a gun barrel capable of temperatures up to 600 Celsius; (2) To examine the influence of temperature, texture, and extrusion velocity in Tantalum; (3) Constrain parameters to improve and assist in constitutive model development using high speed imaging & PDV (in-situ); (4) Understanding microstructural development in materials using the dynamic extrusion technique; and (5) Use as a validation test for developing fracture models important to industry, the DoD, and the DOE.

  17. Mechanical anisotropy of a gamma titanium aluminide alloy after hot extrusion

    SciTech Connect

    Oehring, M.; Lorenz, U.; Niefanger, R.; Appel, F.; Brokmeier, H.G.; Wagner, R.; Clemens, H.; Eberhardt, N.

    1999-07-01

    By hot extrusion below and above the {alpha} transus temperature equiaxed and predominantly lamellar microstructures were obtained in a Ti aluminide alloy. In order to examine a possible orientation dependence of mechanical properties the flow stress, the activation parameters of plastic deformation and the fracture toughness were determined parallel and perpendicular to the extrusion direction at room temperature and 700 C. The observed anisotropy in these properties may be mainly attributed to anisotropies in the microstructures, in particular to a preferential alignment of lamellae in lamellar microstructures.

  18. Dissolution and Separation of Aluminum and Aluminosilicates

    DOE PAGESBeta

    McFarlane, Joanna; Benker, Dennis; DePaoli, David W.; Felker, Leslie Kevin; Mattus, Catherine H.

    2015-12-19

    The selection of an aluminum alloy for target irradiation affects post-irradiation target dissolution and separations. Recent tests with aluminum alloy 6061 yielded greater than expected precipitation in the dissolver, forming up to 10 wt.% solids of aluminum hydroxides and aluminosilicates. Aluminosilicate dissolution presents challenges in a number of different areas, metals extraction from minerals, flyash treatment, and separations from aluminum alloys. We present experimental work that attempts to maximize dissolution of aluminum metal, along with silicon, magnesium, and copper impurities, through control of temperature, the rate of reagent addition, and incubation time. Aluminum phase transformations have been identified as amore » function of time and temperature, using X-ray diffraction. Solutions have been analyzed using wet chemical methods and X-ray fluorescence. Our data have been compared with published calculations of aluminum phase diagrams. Approaches are given to enhance the dissolution of aluminum and aluminosilicate phases in caustic solution.« less

  19. Dissolution and Separation of Aluminum and Aluminosilicates

    SciTech Connect

    McFarlane, Joanna; Benker, Dennis; DePaoli, David W.; Felker, Leslie Kevin; Mattus, Catherine H.

    2015-12-19

    The selection of an aluminum alloy for target irradiation affects post-irradiation target dissolution and separations. Recent tests with aluminum alloy 6061 yielded greater than expected precipitation in the dissolver, forming up to 10 wt.% solids of aluminum hydroxides and aluminosilicates. Aluminosilicate dissolution presents challenges in a number of different areas, metals extraction from minerals, flyash treatment, and separations from aluminum alloys. We present experimental work that attempts to maximize dissolution of aluminum metal, along with silicon, magnesium, and copper impurities, through control of temperature, the rate of reagent addition, and incubation time. Aluminum phase transformations have been identified as a function of time and temperature, using X-ray diffraction. Solutions have been analyzed using wet chemical methods and X-ray fluorescence. Our data have been compared with published calculations of aluminum phase diagrams. Approaches are given to enhance the dissolution of aluminum and aluminosilicate phases in caustic solution.

  20. Nitriding of large-sized aluminum

    SciTech Connect

    Ito, Shigeru; Yoshida, Kazuharu; Sato, Shin-ichi

    1996-06-01

    Aluminum chips with 2mm in size have been successfully nitrided with 99.3% of conversion, using yttrium oxide as a promoter. The product consisted of hollow spheres with 2mm in dia. and fine particles of aluminum nitride. This nitriding is divided into two steps. In the first step, nitriding begins from the surface of aluminum chip. Because the surface is activated by the addition of yttrium oxide, the reaction heat raises the temperature of aluminum enough to generate the aluminum vapor, followed by the second step; exothermic reaction of aluminum vapor and nitrogen gas. In addition, to accelerate the first step without additive, electrolytic etching was applied to aluminum wires with 2mm in dia. In this case, aluminum wires were also completely nitrided.

  1. Aluminum: World market prospects for troubled times

    NASA Astrophysics Data System (ADS)

    Djukanovic, Goran

    2009-02-01

    Aluminum and alumina prices and production volumes dropped significantly in 2008 due to the worldwide economic recession. This paper provides a comprehensive analysis of the current state of the aluminum industry and its outlook for the future.

  2. Aluminum nitride insulating films for MOSFET devices

    NASA Technical Reports Server (NTRS)

    Lewicki, G. W.; Maserjian, J.

    1972-01-01

    Application of aluminum nitrides as electrical insulator for electric capacitors is discussed. Electrical properties of aluminum nitrides are analyzed and specific use with field effect transistors is defined. Operational limits of field effect transistors are developed.

  3. Concentrations and toxicity of fumonisin B1 in fermented corn grits are reduced by extrusion cooking with glucose supplementation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extrusion is a cooking method in which dough is forced under high pressure through a heated barrel using one (single-screw configuration) or two (twin-screw configuration) augers. In an earlier experiment (Voss et al., J. Food Protec. 71: 2036-2041, 2008), extrusion using the single screw configura...

  4. Fatigue-crack propagation in aluminum-lithium alloys processed by power and ingot metallurgy

    SciTech Connect

    Venkateswara Rao, K.T.; Ritchie, R.O. ); Kim, N.J. ); Pizzo, P.P. )

    1990-04-01

    Fatigue-crack propagation behavior in powder-metallurgy (P/M) aluminum-lithium alloys, namely, mechanically-alloyed (MA) Al-4.0Mg-1.5Li-1.1C-0.80{sub 2} (Inco 905-XL) and rapid-solidification-processed (RSP) Al-2.6Li-1.0Cu-0.5Mg-0.5Zr (Allied 644-B) extrusions, has been studied, and results compared with data on an equivalent ingot-metallurgy (I/M) Al-Li alloy, 2090-T81 plate. Fatigue-crack growth resistance of the RSP Al-Li alloy is found to be comparable to the I/M Al-Li alloy; in contrast, crack velocities in MA 905-XL extrusions are nearly three orders of magnitude faster. Growth-rate response in both P/M Al-Li alloys, however, is high anisotropic. Results are interpreted in terms of the microstructural influence of strengthening mechanism, slip mode, grain morphology and texture on the development of crack-tip shielding from crack-path deflection and crack closure. 14 refs., 7 figs., 2 tabs.

  5. 75 FR 70689 - Kaiser Aluminum Fabricated Products, LLC; Kaiser Aluminum-Greenwood Forge Division; Currently...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-18

    ... in the Federal Register on November 17, 2009 (74 FR 59254). At the request of the State agency and a... Employment and Training Administration Kaiser Aluminum Fabricated Products, LLC; Kaiser Aluminum- Greenwood... Aluminum Fabricated Products, LLC, Kaiser Aluminum-Greenwood Forge Division, including on- site...

  6. The effect of zinc on the aluminum anode of the aluminum-air battery

    NASA Astrophysics Data System (ADS)

    Tang, Yougen; Lu, Lingbin; Roesky, Herbert W.; Wang, Laiwen; Huang, Baiyun

    Aluminum is an ideal material for batteries, due to its excellent electrochemical performance. Herein, the effect of zinc on the aluminum anode of the aluminum-air battery, as an additive for aluminum alloy and electrolytes, has been studied. The results show that zinc can decrease the anodic polarization, restrain the hydrogen evolution and increase the anodic utilization rate.

  7. Thermomechanical treatment of 2124 PM aluminum alloys with low and high dispersoid levels

    NASA Technical Reports Server (NTRS)

    Sarkar, B.; Lisagor, W. B.

    1986-01-01

    The effects of thermomechanical treatment (TMT) on the mechanical properties and metallurgical structure of 2124 powder metallurgy aluminum alloys prepared from rapidly solidified powders were investigated. The alloys were prepared by using a standard canning/vacuum degassing/hot consolidation/extrusion sequence. Two compositions, with manganese contents of 0.5 and 1.5 percent, were investigated to examine the effects of low and high dispersoid levels. The results indicate that significant improvements in strength can be accomplished through TMT for this PM alloy system with little loss in toughness. The increase in strength observed is attributed to the presence of much finer, more homogeneous S-prime precipitation than that observed without TMT. Rolling deformation at room temperature resulted in some tendency for nonuniform (planar) deformation and resulted in slightly lower notch strength values. The lower notch strengths observed in the higher manganese composition were attributed to the coarser, more dense dispersoids observed in this material.

  8. RECOVERY OF ALUMINUM FROM FISSION PRODUCTS

    DOEpatents

    Blanco, R.E.; Higgins, I.R.

    1962-11-20

    A method is given for recovertng aluminum values from aqueous solutions containing said values together with fission products. A mixture of Fe/sub 2/O/ sub 3/ and MnO/sub 2/ is added to a solution containing aluminum and fission products. The resulting aluminum-containing supernatant is then separated from the fission product-bearing metal oxide precipitate and is contacted with a cation exchange resin. The aluminum sorbed on the resin is then eluted and recovered. (AEC)

  9. Mineral resource of the month: aluminum

    USGS Publications Warehouse

    Bray, E. Lee

    2012-01-01

    The article offers information on aluminum, a mineral resource which is described as the third-most abundant element in Earth's crust. According to the article, aluminum is the second-most used metal. Hans Christian Oersted, a Danish chemist, was the first to isolate aluminum in the laboratory. Aluminum is described as lightweight, corrosion-resistant and an excellent conductor of electricity and heat.

  10. Mechanical strength of extrusion briquettes (BREX) for blast-furnace and ferroalloy production: II. Effect of the method of grinding coke breeze on the strength of extrusion briquettes

    NASA Astrophysics Data System (ADS)

    Bizhanov, A. M.; Kurunov, I. F.; Dashevskii, V. Ya.

    2015-05-01

    The influence of the method of grinding coke breeze on the strength and the behavior of extrusion briquette (BREX) during static loading is studied. It is found that the size, the shape, and the surface relief of coke breeze particles affect the character of BREX fracture. The application of a shearing extruder for preliminary refinement of coke breeze can result in viscoelastic fracture of BREX due to an increase in its impact toughness.

  11. Blood aluminum levels as a function of aluminum intake from drinking water

    SciTech Connect

    Turnquest, E.M.; Hallenbeck, W.H. )

    1991-04-01

    Questions regarding the health effects of aluminum are still unanswered. The speciation, pharmacokinetics, and toxicity of aluminum are not well understood. Furthermore, no animal or human studies of aluminum absorption have been reported using drinking water as the source of aluminum. The following experiment attempted to reach a better understanding of the bioavailability of aluminum from drinking water. Its objective was to determine whether or not increased aluminum ingestion from drinking water would be reflected in increased serum and whole blood aluminum levels in the baboon experimental model.

  12. Novel aqueous aluminum/sulfur batteries

    SciTech Connect

    Licht, S.; Peramunage, D. )

    1993-01-01

    Aluminum sulfur batteries based on concentrated polysulfide catholytes and an alkaline aluminum anode are introduced and investigated. The new battery is expressed by aluminum oxidation and aqueous sulfur reduction for an overall battery discharge consisting of 2Al + S[sub 4][sup 2[minus

  13. 21 CFR 73.2645 - Aluminum powder.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Aluminum powder. 73.2645 Section 73.2645 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2645 Aluminum powder. (a) Identity and specifications. The color additive aluminum powder shall conform in identity and specifications to the requirements...

  14. 21 CFR 182.1125 - Aluminum sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Aluminum sulfate. 182.1125 Section 182.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Substances § 182.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This...

  15. 21 CFR 172.310 - Aluminum nicotinate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Aluminum nicotinate. 172.310 Section 172.310 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Special Dietary and Nutritional Additives § 172.310 Aluminum nicotinate. Aluminum nicotinate may be...

  16. 21 CFR 172.310 - Aluminum nicotinate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Aluminum nicotinate. 172.310 Section 172.310 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Special Dietary and Nutritional Additives § 172.310 Aluminum nicotinate. Aluminum nicotinate may be...

  17. 21 CFR 182.1125 - Aluminum sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Aluminum sulfate. 182.1125 Section 182.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Substances § 182.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This...

  18. 21 CFR 582.1125 - Aluminum sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Aluminum sulfate. 582.1125 Section 582.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This...

  19. 21 CFR 582.1125 - Aluminum sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Aluminum sulfate. 582.1125 Section 582.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This...

  20. 21 CFR 172.310 - Aluminum nicotinate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Aluminum nicotinate. 172.310 Section 172.310 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Additives § 172.310 Aluminum nicotinate. Aluminum nicotinate may be safely used as a source of niacin...

  1. 21 CFR 182.1125 - Aluminum sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Aluminum sulfate. 182.1125 Section 182.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Substances § 182.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This...

  2. 21 CFR 582.1125 - Aluminum sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Aluminum sulfate. 582.1125 Section 582.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This...

  3. 21 CFR 582.1125 - Aluminum sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Aluminum sulfate. 582.1125 Section 582.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This...

  4. 21 CFR 582.1125 - Aluminum sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Aluminum sulfate. 582.1125 Section 582.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This...

  5. 21 CFR 172.310 - Aluminum nicotinate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Aluminum nicotinate. 172.310 Section 172.310 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Special Dietary and Nutritional Additives § 172.310 Aluminum nicotinate. Aluminum nicotinate may be...

  6. 21 CFR 182.1125 - Aluminum sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Aluminum sulfate. 182.1125 Section 182.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Substances § 182.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This...

  7. 21 CFR 73.2645 - Aluminum powder.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Aluminum powder. 73.2645 Section 73.2645 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2645 Aluminum powder. (a) Identity and specifications. The color additive aluminum powder shall conform in identity and specifications to the requirements...

  8. 21 CFR 182.1125 - Aluminum sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Aluminum sulfate. 182.1125 Section 182.1125 Food... GENERALLY RECOGNIZED AS SAFE Multiple Purpose GRAS Food Substances § 182.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This substance is generally recognized as safe when used...

  9. 21 CFR 172.310 - Aluminum nicotinate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Aluminum nicotinate. 172.310 Section 172.310 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Special Dietary and Nutritional Additives § 172.310 Aluminum nicotinate. Aluminum nicotinate may be...

  10. 21 CFR 73.2645 - Aluminum powder.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Aluminum powder. 73.2645 Section 73.2645 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2645 Aluminum powder. (a) Identity and specifications. The color additive aluminum powder shall conform in identity and specifications to the requirements...

  11. [Current researches on biological effect of aluminum].

    PubMed

    Wang, Jin

    2002-08-01

    Aluminum content is generally not high (less that 10 mg/kg) in most foods with the exception of a few such as tea, spinach, and so on, that contain more amounts of it. However, aluminum content is much high in foods in those aluminum-containing food additives are used. After drinking water is treated with aluminum-containing coagulant agent, it's aluminum concentration increases. The aluminum intake of residents from cookware in our country is 4 mg/(capit.d). The aluminum intake in adults is usually 10 mg/(capit.d), but it will rise up to tens to hundreds mg/(capit.d) when residents consume foods with a high aluminum concentration or aluminum-containing drugs. Aluminum is absorbed mainly via a duodenum, and this can be influenced by multiple factors. Absorbed aluminum is discharged primarily by renal excretion. Aluminum accumulation in human body might harm central nervous system, bone lesions, and hemopoietic system, and is a suspected causal factor to Alzheimer's disease. PMID:12600050

  12. 21 CFR 73.2645 - Aluminum powder.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Aluminum powder. 73.2645 Section 73.2645 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2645 Aluminum powder. (a) Identity and specifications. The color additive aluminum powder shall conform in identity and specifications to the requirements...

  13. 21 CFR 73.2645 - Aluminum powder.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Aluminum powder. 73.2645 Section 73.2645 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2645 Aluminum powder. (a) Identity and specifications. The color additive aluminum powder shall conform in identity and specifications to the requirements...

  14. Recovering aluminum from aluminum dross in a DC electric-arc rotary furnace

    NASA Astrophysics Data System (ADS)

    Tzonev, Tz.; Lucheva, B.

    2007-11-01

    The recycling of aluminum scrap and dross yields significant economic and energy savings, as well environmental benefits. The recovery of aluminum depends on many factors. The aim of this work is to experimentally investigate aluminum recovery under different conditions. In this study, aluminum dross was processed in a direct-current electric-arc rotary furnace. The presence of crushing refractory bodies during processing was found to increase the degree of aluminum recovery by about ten percent.

  15. Inert anodes for aluminum smelting

    SciTech Connect

    Weyand, J.D.; Ray, S.P.; Baker, F.W.; DeYoung, D.H.; Tarcy, G.P.

    1986-02-01

    The use of nonconsumable or inert anodes for replacement of consumable carbon anodes in Hall electrolysis cells for the production of aluminum has been a technical and commercial goal of the aluminum industry for many decades. This report summarizes the technical success realized in the development of an inert anode that can be used to produce aluminum of acceptable metal purity in small scale Hall electrolysis cells. The inert anode material developed consists of a cermet composition containing the phases: copper, nickel ferrite and nickel oxide. This anode material has an electrical conductivity comparable to anode carbon used in Hall cells, i.e., 150 ohm {sup {minus}1}cm{sup {minus}1}. Metal purity of 99.5 percent aluminum has been produced using this material. The copper metal alloy present in the anode is not removed by anodic dissolution as does occur with cermet anodes containing a metallic nickel alloy. Solubility of the oxide phases in the cryolite electrolyte is reduced by: (1) saturated concentration of alumina, (2) high nickel oxide content in the NiO-NiFe{sub 2}O{sub 4} composition, (3) lowest possible cell operating temperature, (4) additions of alkaline or alkaline earth fluorides to the bath to reduce solubilities of the anode components, and (5) avoiding bath contaminants such as silica. Dissolution rate measurements indicate first-order kinetics and that the rate limiting step for dissolution is mass transport controlled. 105 refs., 234 figs., 73 tabs.

  16. Directly polished lightweight aluminum mirror

    NASA Astrophysics Data System (ADS)

    ter Horst, Rik; Tromp, Niels; de Haan, Menno; Navarro, Ramon; Venema, Lars; Pragt, Johan

    2008-07-01

    During the last ten years, Astron has been a major contractor for the design and manufacturing of astronomical instruments for Space- and Earth based observatories, such as VISIR, MIDI, SPIFFI, X-Shooter and MIRI. The collaboration between optical- and mechanical designers at Astron led to new design philosophies and strategies. Driven by the need to reduce the weight of optically ultra-stiff structures, two promising techniques have been developed in the last years: ASTRON Extreme Lightweighting for mechanical structures and an improved Polishing Technique for Aluminum Mirrors. Using one single material for both optical components and mechanical structure simplifies the design of a cryogenic instrument significantly, it is very beneficial during instrument test and verification, and makes the instrument insensitive to temperature changes. Aluminum has been the main material used for cryogenic optical instruments, and optical aluminum mirrors are generally diamond turned. The application of a polishable hard top coating like nickel removes excess stray light caused by the groove pattern, but limits the degree of lightweighting of the mirrors due to the bi-metal effect. By directly polishing the aluminum mirror surface, the recent developments at Astron allow for using a non-exotic material for light weighted yet accurate optical mirrors, with a lower surface roughness (~1nm RMS), higher surface accuracy and reduced light scattering. This paper presents the techniques, obtained results and a global comparison with alternative lightweight mirror solutions.

  17. Aluminum: The Next Twenty Years

    NASA Astrophysics Data System (ADS)

    Fitzgerald, M. Desmond; Pollio, Gerald

    1982-12-01

    This report concludes that the outlook for the world aluminum industry is quite favorable. Demand is expected to expand at a more rapid rate than for other basic metals, but not sufficiently to put undue strain on productive capacity. Capital requirements of the world aluminum industry are projected at 95.5 billion in 1980 prices — more than 200 billion in current prices—over the balance of the century. Given the aluminum industry's past success in generating internal funds, this level of capital expanditure should not cause undue financing problems. Finally, we expect changes to occur in the structure of the industry over the forecast period, with virtually all new alumina capacity being installed in proximity to bauxite production, and—with the exception of Australia—a major shift in smelting capacity away from other industrialized economies. While the large multinational companies will still play a dominant role in the world aluminum market, their share of production and ownership is likely to decline progressively during the period.

  18. Characterizatin of ultrafine aluminum nanoparticles

    SciTech Connect

    Sandstrom, M. M.; Jorgensen, B. S.; Mang, J. T.; Smith, B. L.; Son, S. F.

    2004-01-01

    Aluminum nanopowders with particle sizes ranging from {approx}25 nm to 80 nm were characterized by a variety of methods. We present and compare the results from common powder characterization techniques including transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), BET gas adsorption surface area analysis, thermogravimetric analysis (TGA), photon correlation spectroscopy (PCS), and low angle laser light scattering (LALLS). Aluminum nanoparticles consist of an aluminum core with an aluminum oxide coating. HRTEM measurements of both the particle diameter and oxide layer thickness tend to be larger than those obtained from BET and TGA. LALLS measurements show a large degree of particle agglomeration in solution; therefore, primary particle sizes could not be determined. Furthermore, results from small-angle scattering techniques (SAS), including small-angle neutron (SANS) and x-ray (SAXS) scattering are presented and show excellent agreement with the BET, TGA, and HRTEM. The suite of analytical techniques presented in this paper can be used as a powerful tool in the characterization of many types of nanosized powders.

  19. Aluminum and its light alloys

    NASA Technical Reports Server (NTRS)

    Merica, Paul D

    1920-01-01

    Report is a summary of research work which has been done here and abroad on the constitution and mechanical properties of the various alloy systems with aluminum. The mechanical properties and compositions of commercial light alloys for casting, forging, or rolling, obtainable in this country are described.

  20. Effects of pelleting, extrusion, or extrusion and pelleting on energy and nutrient digestibility in diets containing different levels of fiber and fed to growing pigs.

    PubMed

    Rojas, O J; Vinyeta, E; Stein, H H

    2016-05-01

    An experiment was conducted to determine effects of pelleting, extrusion, and extrusion and pelleting on energy and nutrient digestibility in diets containing low, medium, or high concentrations of fiber. Three diets were formulated: 1) the low-fiber diet contained corn and soybean meal; 2) the medium-fiber diet contained corn, soybean meal, and 25% distillers dried grains with solubles (DDGS); and 3) the high-fiber diet contained corn, soybean meal, 25% DDGS, and 20% soybean hulls. Each diet was divided into 4 batches after mixing. One batch was not further processed and was fed in a meal form, one batch was pelleted at 85°C, one batch was extruded at 115°C using a single-screw extruder, and one batch was extruded at 115°C and then pelleted at 85°C. Thus, 12 different diets were produced. Twenty-four growing pigs (26.5 ± 1.5 kg initial BW) had a T-cannula installed in the distal ileum and were allotted to the 12 diets in a split-plot design with 8 pigs allotted to the low-fiber diets, the medium-fiber diets, and the high-fiber diets, respectively. Diets were fed to the pigs during four 14-d periods. Within each type of diet, the 8 pigs were fed the diets produced using the 4 processing technologies. Therefore, there were 8 replicate pigs per diet. Pigs were adjusted to their diets for 14 d before the experiment was initiated. Each of the four 14-d periods consisted of 5 d for adaptation, 5 d of fecal collection according to the marker to marker approach, and ileal digesta were collected on d 13 and 14. Results indicated that pelleting, extrusion, or extrusion and pelleting improved ( < 0.05) the apparent ileal digestibility of starch and most indispensable AA. In most cases, there were no differences between the pelleted, the extruded, and the extruded and pelleted diets. The apparent total tract digestibility of GE was also improved ( < 0.05) by pelleting and by the combination of extrusion and pelleting. The ME of pelleted diets was greater ( < 0.05) than

  1. Soft magnetic composites manufactured by warm co-extrusion of bulk metallic glass and steel powders

    SciTech Connect

    Johnson, Francis; Raber, Thomas R.; Zabala, Robert J.; Buresh, Steve J.; Tanico, Brian

    2013-05-07

    Soft magnetic composites of Fe-based bulk metallic glass and low-alloy steel have been manufactured by warm co-extrusion of precursor powders at temperatures within the supercooled liquid region of the glass. Composites were manufactured with amorphous volume fractions of 75%, 67%, and 100%. Full consolidation of the constituent powders was observed with the bulk metallic glass remaining substantially amorphous. The composite electrical resistivity was observed to be anisotropic with a resistivity of 79 {mu}{Omega} cm measured transverse to the extrusion axis in a sample with 75% amorphous volume fraction. A 0-3 connectivity pattern with the low-resistivity steel phase embedded in a 3-dimensionally connected high-resistivity bulk metallic glass phase was observed with scanning electron microscopy. This confirms that the flow characteristics of the bulk metallic glass and the steel powders were comparable during extrusion at these temperatures. The saturation magnetization of 1.3 T was consistent with the volume weighted average of the saturation magnetization of the two phases. A relatively high quasistatic coercivity of 8 Oe was measured and is likely due to slight crystallization of the bulk metallic glass as well as domain wall pinning at prior particle boundaries. Careful control of the thermal environment during the extrusion process is required to minimize glass crystallization and achieve the desired balance of magnetic and electrical properties.

  2. Microstructures and Thermal Properties of Mg-Sn-Ca Alloys: Casts and Extrusions

    NASA Astrophysics Data System (ADS)

    Kim, Jung-Han; Choi, Jeong-Won; Kim, Yong-Ho; Yoo, Hyo-Sang; Woo, Kee-Do; Lee, Seong-Hee; Son, Hyeon-Taek

    2015-11-01

    Microstructure and thermal properties of Mg-(3 mass% or 5 mass%) Sn-2 mass% Ca alloys as casts and extrusions have been investigated with different ram speeds and extrusion temperatures. Mg-(3 mass% or 5 mass%) Sn-2 mass% Ca alloys are composed of \\upalpha -Mg, MgSnCa, and {Mg}2{Ca} phases. By adding Sn content from 3 mass% to 5 mass%, the MgSnCa phase is increased and the {Mg}2{Ca} phase is decreased. During hot extrusion, the average grain sizes are increased with increasing ram speed and temperature. The ultimate tensile strength ( UTS) and elongation for the Mg-5Sn-2Ca alloy at 2.3 {mm}{\\cdot }{s}^{-1} are 227.73 MPa and 18.43 %, respectively. With increasing extrusion ram speed, the UTS and elongation for the Mg-5Sn-2Ca alloy are remarkably decreased to 215.95 MPa, 206.33 MPa, and 14.74 %, 6.88 %, respectively. The thermal conductivity for the Mg-3Sn-2Ca alloy is dramatically improved, compared to commercialized Mg alloys such as AZ31 and AZ91 due to formation of MgSnCa and {Mg}2{Ca} phases.

  3. Efficient continuous synthesis of high purity deep eutectic solvents by twin screw extrusion.

    PubMed

    Crawford, D E; Wright, L A; James, S L; Abbott, A P

    2016-03-18

    Mechanochemical synthesis has been applied to the rapid synthesis of Deep Eutectic Solvents (DESs), including Reline 200 (choline chloride : urea, 1 : 2), in a continuous flow methodology by Twin Screw Extrusion (TSE). This gave products in higher purity and with Space Time Yields (STYs), four orders of magnitude greater than for batch methods. PMID:26911554

  4. Plasticity mechanism for copper extrusion in through-silicon vias for three-dimensional interconnects

    NASA Astrophysics Data System (ADS)

    Jiang, Tengfei; Wu, Chenglin; Spinella, Laura; Im, Jay; Tamura, Nobumichi; Kunz, Martin; Son, Ho-Young; Gyu Kim, Byoung; Huang, Rui; Ho, Paul S.

    2013-11-01

    In this paper, we demonstrated the plasticity mechanism for copper (Cu) extrusion in through-silicon via structures under thermal cycling. The local plasticity was directly observed by synchrotron x-ray micro-diffraction near the top of the via with the amount increasing with the peak temperature. The Cu extrusion was confirmed by Atomic Force Microscopy (AFM) measurements and found to be consistent with the observed Cu plasticity behavior. A simple analytical model elucidated the role of plasticity during thermal cycling, and finite element analyses were carried out to confirm the plasticity mechanism as well as the effect of the via/Si interface. The model predictions were able to account for the via extrusions observed in two types of experiments, with one representing a nearly free sliding interface and the other a strongly bonded interface. Interestingly, the AFM extrusion profiles seemed to contour with the local grain structures near the top of the via, suggesting that the grain structure not only affects the yield strength of the Cu and thus its plasticity but could also be important in controlling the pop-up behavior and the statistics for a large ensemble of vias.

  5. The effect of extrusion on the fumonisin content and toxicity of corn grits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extrusion cooking reduces fumonisin concentrations in corn; however, the nature and toxicity of fumonisin reaction products in food matrices are not well understood. Corn grits were contaminated by spiking with fumonisin B1 (FB1) (Spiked grits = SG, 43 nmol/g dry wt FB1; measured by LC-MS) or by fer...

  6. Reduced toxicity of fumonisin B1 in corn grits by single-screw extrusion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extrusion cooking under conditions of high heat and pressure reduces the concentration of fumonisins in corn-based products; however, the toxicity of heretofore uncharacterized fumonisin reactions products in extruded materials has not been determined. Uncontaminated corn grits, grits spiked with 3...

  7. COST OF EXTRUSION PROCESSING OF COTTON GIN BY-PRODUCTS AS LIVESTOCK FEED

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extrusion processing can be used on cotton gin by-product (CGB)to produce livestock feed (roughage) products. Using the economic-engineering approach, estimates of unit processing cost for CGB livestock feed products were developed, indicating economies of size, with average per-ton cost as low as $...

  8. Twin screw extrusion processing of feed blends containing distillers dried grains with solubles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extrusion trials were conducted with varying levels of distillers dried grains with solubles (DDGS) along with soy flour, corn flour, fish meal, vitamin mix, mineral mix and net protein content adjusted to 28% using a Wenger TX-52 twin screw extruder. The properties of extrudates obtained with exper...

  9. Neural network and regression modeling of extrusion processing parameters and properties of extrudates containing DDGS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two extrusion experiments using a single screw extruder were conducted with an ingredient blend containing 40% DDGS, along with soy flour, corn flour, fish meal, vitamin mix, and mineral mix, with the net protein content adjusted to 28%. The variables controlled in the first experiment included 7 le...

  10. Effects of extrusion cooking on the chemical composition and functional properties of dry bean powders

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study aimed to investigate the impacts of extrusion cooking on the chemical composition and functional properties of bean powders from four bean varieties. The raw bean powders were extruded under eight different conditions, and the extrudates were then dried and ground (particle size = 0.5 mm)...

  11. Effects of extrusion cooking on physicochemical properties of white and red ginseng (powder)

    PubMed Central

    Gui, Ying; Ryu, Gi-Hyung

    2013-01-01

    A systematic comparison of the physicochemical properties of white ginseng (WG), extruded white ginseng (EWG), red ginseng (RG), and extruded red ginseng (ERG) was performed. The aim of the present study was to identify the effects of the physicochemical properties of ginseng by extrusion cooking. The highest value of the water absorption index (WAI) was 3.64 g/g obtained from EWG, and the highest value of the water solubility index (WSI) was 45.27% obtained from ERG. The ERG had a better dispersibility compared with other samples. Extrusion cooking led to a significant increase in acidic polysaccharide and total sugar content but resulted in a decrease in crude fat and reducing sugar contents. Enzyme treatment led to a sharp increase in acidic polysaccharide content, especially the cellulose enzyme. Extrusion cooking led to a significant increase in 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and reducing power, and the increases in WG and RG were 13.56% (0.038) and 3.56% (0.026), respectively. The data of this study provide valuable information about the effects of extrusion on quality changes of EWG and ERG. PMID:24748839

  12. Neural Network and Regression Modeling of Extrusion processing Parameters and Properties of Extrudates containing DDGS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two extrusion experiments using a single screw extruder were conducted with an ingredient blend containing 40% DDGS, along with soy flour, corn flour, fish meal, vitamin mix, and mineral mix, with the net protein content adjusted to 28%. The variables controlled in the first experiment included 7 le...

  13. Rheological properties of reactive extrusion modified waxy starch and waxy starch-polyacrylamide copolymer gels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The rheological properties of modified waxy starch and waxy starch-polyacrylamide graft copolymers prepared by reactive extrusion were investigated. Both materials can absorb huge amount of water and form gels. The modified waxy starch and waxy starch-polyacrylamide graft copolymer gels all exhibite...

  14. Suppression of repeated adiabatic shear banding by dynamic large strain extrusion machining

    NASA Astrophysics Data System (ADS)

    Cai, S. L.; Dai, L. H.

    2014-12-01

    High speed machining (HSM) is an advanced production technology with great future potential. Chip serration or segmentation is a commonly observed phenomenon during high speed machining of metals, which is found to be ascribed to a repeated shear band formation fueled by thermo-plastic instability occurring within the primary shear zone. The occurrence of serrated chips leads to the cutting force fluctuation, decreased tool life, degradation of the surface finish and less accuracy in machine parts during high speed machining. Hence, understanding and controlling serrated chip formation in HSM are extremely important. In this work, a novel dynamic large strain extrusion machining (DLSEM) technique is developed for suppressing formation of serrated chips. The systematic DLSEM experiments of Ti-6Al-4V and Inconel 718 alloy with varying degrees of imposed extrusion constraint were carried out. It is found that there is a prominent chip morphology transition from serrated to continuous state and shear band spacing decreases with the constraint degree increasing. In order to uncover underlying mechanism of the imposed extrusion constraint suppressing repeated adiabatic shear banding in DLSEM, new theoretical models are developed where the effects of extrusion constraint, material convection due to chip flow and momentum diffusion during shear band propagation are included. The analytical expressions for the onset criterion of adiabatic shear band and shear band spacing in DLSEM are obtained. The theoretical predictions are in agreement with the experimental results.

  15. Soft magnetic composites manufactured by warm co-extrusion of bulk metallic glass and steel powders

    NASA Astrophysics Data System (ADS)

    Johnson, Francis; Raber, Thomas R.; Zabala, Robert J.; Buresh, Steve J.; Tanico, Brian

    2013-05-01

    Soft magnetic composites of Fe-based bulk metallic glass and low-alloy steel have been manufactured by warm co-extrusion of precursor powders at temperatures within the supercooled liquid region of the glass. Composites were manufactured with amorphous volume fractions of 75%, 67%, and 100%. Full consolidation of the constituent powders was observed with the bulk metallic glass remaining substantially amorphous. The composite electrical resistivity was observed to be anisotropic with a resistivity of 79 μΩ cm measured transverse to the extrusion axis in a sample with 75% amorphous volume fraction. A 0-3 connectivity pattern with the low-resistivity steel phase embedded in a 3-dimensionally connected high-resistivity bulk metallic glass phase was observed with scanning electron microscopy. This confirms that the flow characteristics of the bulk metallic glass and the steel powders were comparable during extrusion at these temperatures. The saturation magnetization of 1.3 T was consistent with the volume weighted average of the saturation magnetization of the two phases. A relatively high quasistatic coercivity of 8 Oe was measured and is likely due to slight crystallization of the bulk metallic glass as well as domain wall pinning at prior particle boundaries. Careful control of the thermal environment during the extrusion process is required to minimize glass crystallization and achieve the desired balance of magnetic and electrical properties.

  16. Ethanol-Induced Activation of ATP-Dependent Proton Extrusion in Elodea densa Leaves 1

    PubMed Central

    Marrè, Maria T.; Venegoni, Alberto; Moroni, Anna

    1992-01-01

    In Elodea densa leaves, ethanol up to 0.17 m stimulates H+ extrusion activity. This effect is strictly dependent on the presence of K+ in the medium and is suppressed by the presence of the plasmalemma H+-ATPase inhibitor vanadate. Stimulation of H+ extrusion is associated with (a) a decrease in cellular ATP level, (b) a marked hyperpolarization of transmembrane electrical potential, and (c) an increase in net K+ influx. These results suggest that ethanol-induced H+ extrusion is mediated by an activation of the plasma membrane ATP-dependent, electrogenic proton pump. This stimulating effect is associated with an increase of cell sap pH and of the capacity to take up the weak acid 5,5-dimethyloxazolidine-2,4-dione, which is interpretable as due to an increase of cytosolic pH. This indicates that the stimulation of H+ extrusion by ethanol does not depend on a cytosolic acidification by products of ethanol metabolism. The similarity of the effects of ethanol and those of photosynthesis on proton pump activity in E. densa leaves suggests that a common metabolic situation is responsible for the activation of the ATP-dependent H+-extruding mechanism. PMID:16653093

  17. Fate of Fusarium mycotoxins in maize flour and grits during extrusion cooking.

    PubMed

    Scudamore, Keith A; Guy, Robin C E; Kelleher, Brian; MacDonald, Susan J

    2008-11-01

    Extrusion technology is used widely in the manufacture of a range of breakfast cereals and snacks for human consumption and animal feeds. To minimise consumer exposure to mycotoxins, the levels of deoxynivalenol (DON) and zearalenone (ZON) in cereals/cereal products and fumonisins B(1) and B(2) (FB(1) and FB(2)) in maize are controlled by European Union legislation. Relatively few studies, however, have examined the loss of Fusarium mycotoxins during processing. The behaviour of FB(1), FB(2) and fumonisin B(3) (FB(3)), DON and ZON during extrusion of naturally contaminated maize flour and maize grits is examined using pilot-scale equipment. DON and ZON are relatively stable during extrusion cooking but the fumonisins are lost to varying degrees. There is some loss of ZON when present in low concentrations and extruded at higher moisture contents. The presence of additives, such as reducing sugars and sodium chloride, can also affect mycotoxin levels. Moisture content of the cereal feed during extrusion is important and has a greater effect than temperature, particularly on the loss of fumonisins at the lower moistures. The effects are complex and not easy to explain, although more energy input to the extruder is required for drier materials. However, on the basis of these studies, the relationship between the concentration of Fusarium toxins in the raw and finished product is toxin- and process-dependent. PMID:19680845

  18. Evaluation of sorghum flour as extender in plywood adhesives for sprayline coaters or foam extrusion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was conducted to evaluate sorghum flour as protein extender in plywood adhesive for sprayline coaters or foam extrusion. Defatted sorghum flour, containing 0.2% (dry basis, db) residual oil and 12.0% (db) crude protein, was analyzed for solubility and foaming properties. Sorghum flour pr...

  19. Effect of extrusion processing on immune activation properties of hazelnut protein in a mouse model.

    PubMed

    Ortiz, Tina; Para, Radhakrishna; Gonipeta, Babu; Reitmeyer, Mike; He, Yingli; Srkalovic, Ines; Ng, Perry K W; Gangur, Venu

    2016-09-01

    Although food processing can alter food allergenicity, the impact of extrusion processing on in vivo hazelnut allergenicity is unknown. Here, we tested the hypothesis that extrusion processing will alter the immune activation properties of hazelnut protein (HNP) in mice. Soluble extrusion-processed HNP (EHNP) was prepared and evaluated for immune response using an established transdermal sensitization mouse model. Mice were sensitized with identical amounts of EHNP versus raw HNP. After confirming systemic IgE, IgG1 and IgG2a antibody responses, oral hypersensitivity reaction was quantified by hypothermia shock response (HSR). Mechanism was studied by measuring mucosal mast cell (MMC) degranulation. Compared to raw HNP, the EHNP elicited slower but similar IgE antibody (Ab) response, lower IgG1 but higher IgG2a Ab response. The EHNP exhibited significantly lower oral HSR as well as MMC degranulation capacity. These results demonstrate that the extrusion technology can be used to produce soluble HNP with altered immune activation properties. PMID:27251648

  20. Effect of extrusion cooking, with and without added glucose, on fumonisin B1 in corn grits.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extrusion cooking reduces fumonisin concentrations in corn but how it affects fumonisin toxicity is not well characterized. A batch of corn grits (SG) was spiked with fumonisin B1 (FB1) and two batches (FG1 & FG2) were contaminated with FB1 by fermentation. Respective FB1 concentrations of SG, FG1...

  1. Waxy soft white wheat: extrusion characteristics and thermal and rheological properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Waxy wheat flour was analyzed for its thermal and rheological properties and extruded to understand its processing characteristics. Comparisons were made with normal soft white wheat flour to identify extrusion differences under the same conditions. The thermal and rheological properties through Rap...

  2. Plasticity mechanism for copper extrusion in through-silicon vias for three-dimensional interconnects

    SciTech Connect

    Jiang, Tengfei; Spinella, Laura; Im, Jay; Ho, Paul S.; Wu, Chenglin; Huang, Rui; Tamura, Nobumichi; Kunz, Martin; Son, Ho-Young; Gyu Kim, Byoung

    2013-11-18

    In this paper, we demonstrated the plasticity mechanism for copper (Cu) extrusion in through-silicon via structures under thermal cycling. The local plasticity was directly observed by synchrotron x-ray micro-diffraction near the top of the via with the amount increasing with the peak temperature. The Cu extrusion was confirmed by Atomic Force Microscopy (AFM) measurements and found to be consistent with the observed Cu plasticity behavior. A simple analytical model elucidated the role of plasticity during thermal cycling, and finite element analyses were carried out to confirm the plasticity mechanism as well as the effect of the via/Si interface. The model predictions were able to account for the via extrusions observed in two types of experiments, with one representing a nearly free sliding interface and the other a strongly bonded interface. Interestingly, the AFM extrusion profiles seemed to contour with the local grain structures near the top of the via, suggesting that the grain structure not only affects the yield strength of the Cu and thus its plasticity but could also be important in controlling the pop-up behavior and the statistics for a large ensemble of vias.

  3. Investigation of extrusion failures of PTFE-based gaskets in chemical plant service

    SciTech Connect

    Winter, J.R.; Keywood, S.S.

    1996-12-01

    PTFE-based gaskets in chemical plant service typically fail in an extrusion mode, sometimes referred to as blowout. Test work previously published by Monsanto indicated that correctly installed PTFE-based gaskets have pressure performance far exceeding system pressure ratings. These results have since been confirmed by extensive testing at the Montreal based Ecole Polytechnique Tightness Testing and Research Laboratory (TTRL), funded by a consortium of gasket users and manufacturers. With the knowledge that properly installed gaskets can withstand system pressures in excess of 1,000 psig [6,894 kPa], failures at two chemical plants were re-examined. This analysis indicates that extrusion type failures can be caused by excessive internal pressures, associated with sections of pipe having an external source of heat coincident with a blocked flow condition. This results in high system pressures which explain the extrusion type failures observed. The paper discusses details of individual failures and examines methods to prevent them. Other causes for extrusion failures are reviewed, with a recommendation that stronger gasket materials not be utilized to correct problems until it is verified that excessive pressure build-up is not the problem. Also summarized are the requirements for proper installation to achieve the potential blowout resistance found in these gaskets.

  4. Comparison of Cationic and Unmodified Starches in Reactive Extrusion of Starch-Polyacrylamide Graft Copolymers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Graft copolymers of starch and polyacrylamide (PAAm) were prepared using reactive extrusion in a corotating twin screw extruder. The effect of cationic starch modification was examined using unmodified and cationic dent starch (approximately 23% amylose) and waxy maize starch (approximately 2% amyl...

  5. Study of Microstructure and Mechanical Properties Effects on Workpiece Quality in Sheet Metal Extrusion Process

    PubMed Central

    Suriyapha, Chatkaew; Bubphachot, Bopit; Rittidech, Sampan

    2015-01-01

    Sheet metal extrusion is a metal forming process in which the movement of a punch penetrates a sheet metal surface and it flows through a die orifice; the extruded parts can be deflected to have an extrusion cavity and protrusion on the opposite side. Therefore, this process results in a narrow region of highly localized plastic deformation due to the formation and microstructure effect on the work piece. This research investigated the characteristics of the material-flow behavior during the formation and its effect on the microstructure of the extruded sheet metal using the finite element method (FEM). The actual parts and FEM simulation model were developed using a blank material made from AISI-1045 steel with a thickness of 5 mm; the material's behavior was determined subject to the punch penetration depths of 20%, 40%, 60%, and 80% of the sheet thickness. The results indicated the formation and microstructure effects on the sheet metal extrusion parts and defects. Namely, when increasing penetration, narrowing the die orifice the material flows through, the material was formed by extruding, and defects were visibility, and the microstructure of the material's grains' size was flat and very fine. Extrusion defects were not found in the control material flow. The region of highly localized plastic deformation affected the material gain and mechanical properties. The FEM simulation results agreed with the experimental results. Moreover, FEM could be investigated as a tool to decrease the cost and time in trial and error procedures. PMID:26229979

  6. Detrital zircon provenance evidence for large-scale extrusion along the Altyn Tagh fault

    USGS Publications Warehouse

    Yue, Y.; Graham, S.A.; Ritts, B.D.; Wooden, J.L.

    2005-01-01

    The question of whether or not the Altyn Tagh fault is a large-scale extrusion boundary is critical for understanding the role of lateral extrusion in accommodating the Indo-Asian convergence and in building the Tibetan Plateau. Oligocene conglomerate clasts in the eastern Xorkol basin are low-grade slate, phyllite, sandstone, dacite and carbonate, and associated paleocurrent indicators evince sediment derivation from the opposing side of the Altyn Tagh fault. Matching these clasts with similar basement rocks in the North Qilian and Tuolainanshan terranes requires post-Oligocene left-lateral offset of 380 ?? 60 km on the eastern segment of the Altyn Tagh fault, suggesting large-scale extrusion along the fault in the Cenozoic (Yue, Y.J., Ritts, B.D., Graham, S.A., 2001b. Initiation and long-term slip history of the Altyn Tagh fault. International Geological Review 43, 1087-1094.). In order to further define this piercing point, the detrital zircon pattern of Oligocene sandstone from the Xorkol basin and the zircon ages of basement on the southern side of the fault were established by ion microprobe dating. Characterized by strong peaks between 850 and 950 Ma and the absence of Paleozoic and Mesozoic ages, the detrital zircon age pattern of the Oligocene sandstone matches the age distribution of zircon-bearing rocks of the Tuolainanshan terrane. This match requires 360 ?? 40 km of post-Oligocene left-lateral displacement on the eastern segment of the Altyn Tagh fault, supporting as well as refining the previously reported lithology-based cross-fault match. At least one of the following three extrusion scenarios must have existed to accommodate this large offset: (1) northeastward extrusion along the Altyn Tagh-Alxa-East Mongolia fault, (2) eastward extrusion along the Altyn Tagh-North Qilian-Haiyuan fault, and (3) northeastward extrusion of northern Tibet as a Himalaya-scale thrust sheet along the North Qilian-Haiyuan fault. We prefer the first scenario inasmuch as

  7. The SPASM Model of Seismogenic Solid-state Extrusion at Mount St. Helens

    NASA Astrophysics Data System (ADS)

    Iverson, R. M.

    2007-12-01

    The 2004-2007 eruption of Mount St. Helens (MSH) has been characterized by nearly steady extrusion of a gouge- coated plug of solid dacite and by millions of small (extrusion site. For more than a year these earthquakes occurred so regularly (roughly once a minute) that they were dubbed "drumbeats." A recently derived mathematical model I call SPASM (for Seismogenic Plug of Ascending, Solidifying Magma) formalizes the hypothesis that the drumbeat earthquakes resulted from repetitive stick-slip motion along the subsurface margins of the extruding plug (Nature 244, 439-443, 2006). The model assumes that extrusion is driven by steady discharge of magma from a deep reservoir, and it assesses whether this steady discharge favors stable, steady extrusion at the surface, jerky extrusion characterized by stick-slip cycles, or some alternative behavior such as runaway acceleration or progressive plugging of the conduit. Analysis of the model equations shows that the basic requirements for sustained stick-slip behavior are simple and few: a magma ascent rate comparable to the plug accretion rate, a magma compressibility much greater than that of solid rock, and extrusion resistance provided by gravity and rate-weakening friction along the lateral margins of the solidifying plug. Data show that these requirements were likely met during the first 15 months of the 2004- 2007 MSH eruption. Indeed, with use of reasonable parameter values, the SPASM model yields predictions of repetitive stick-slip cycles with periods and amplitudes commensurate with occurrence of drumbeat earthquakes at MSH. The model also predicts, however, that several phenomena could gradually reduce the tendency for stick-slip behavior (as implied, for example, by diminishing drumbeats observed at MSH in 2006-2007). These phenomena include a decline in magma ascent rate, increase in plug-mass growth rate, and decline of plug- boundary friction or the rate

  8. Decarbonization process for carbothermically produced aluminum

    DOEpatents

    Bruno, Marshall J.; Carkin, Gerald E.; DeYoung, David H.; Dunlap, Sr., Ronald M.

    2015-06-30

    A method of recovering aluminum is provided. An alloy melt having Al.sub.4C.sub.3 and aluminum is provided. This mixture is cooled and then a sufficient amount of a finely dispersed gas is added to the alloy melt at a temperature of about 700.degree. C. to about 900.degree. C. The aluminum recovered is a decarbonized carbothermically produced aluminum where the step of adding a sufficient amount of the finely dispersed gas effects separation of the aluminum from the Al.sub.4C.sub.3 precipitates by flotation, resulting in two phases with the Al.sub.4C.sub.3 precipitates being the upper layer and the decarbonized aluminum being the lower layer. The aluminum is then recovered from the Al.sub.4C.sub.3 precipitates through decanting.

  9. The Surface Tension of Pure Aluminum and Aluminum Alloys

    NASA Astrophysics Data System (ADS)

    Bainbridge, Ian Frank; Taylor, John Andrew

    2013-08-01

    The surface tension of high purity and commercial purity aluminum in vacuo was determined using the sessile drop method and the results were found to compare favorably with published data. The effects of holding atmosphere, substrate, and "surface fracture" of the sessile drop on the measured surface tension values were investigated together with the effects of different solute elements commonly present in commercial aluminum alloys. The results obtained suggest that the nature of the surface oxide film formed on the droplets (affected by alloy composition and atmosphere) and the rupture of this film are the dominant factors influencing the surface tension values obtained. Changes in surface tension values of up to 60 pct were observed. The possible effect of this variable surface tension on practical casting processes, such as direct chill casting, is suggested.

  10. Complex foamed aluminum parts as permanent cores in aluminum castings

    SciTech Connect

    Simancik, F.; Schoerghuber, F.

    1998-12-31

    The feasibility of complex shaped aluminum foam parts as permanent cores in aluminum castings has been investigated. The foamed samples were prepared by injection of the foam into sand molds. It turned out that sound castings can be produced if the foam core is properly preheated and/or surface treated before casting. The effect of the foam core on the performance of the casting was evaluated by in compression testing and by measuring structural damping. The gain in the related properties turned out to be much higher than the weight increase of the casting due to the presence of the core. The weight increase may be partially offset through a reduction of the wall-thickness of the shell.

  11. Explosive Welding of Aluminum to Aluminum: Analysis, Computations and Experiments

    NASA Astrophysics Data System (ADS)

    Grignon, F.; Benson, D.; Vecchio, K. S.; Meyers, M. A.

    2004-07-01

    6061 T0 aluminum alloy was joined to 6061 T0 aluminum alloy by explosive welding. This is a process in which the controlled energy of a detonating explosive is used to create a metallic bond between two similar or dissimilar materials. The welding conditions were tailored to produce both wavy and straight interfaces. A three-pronged study was used to establish the conditions for straight weld formation: (a) analytical calculation of the domain of weldability; (b) characterization of the explosive welding experiments carried out under different conditions, and (c) 2D finite differences simulation of these tests using the explicit Eulerian hydrocode Raven with a Johnson-Cook constitutive equation for the Al alloy. The numerical simulation and the analytical calculations confirm the experimental results and explain the difficulties met for obtaining a continuous straight interface along the entire weld.

  12. Co-extrusion as manufacturing technique for fixed-dose combination mini-matrices.

    PubMed

    Dierickx, L; Saerens, L; Almeida, A; De Beer, T; Remon, J P; Vervaet, C

    2012-08-01

    The aim of this study was to develop a multilayer (core/coat) dosage form via co-extrusion, the core providing sustained drug release and the coat immediate drug release. In this study polymers were selected which can be combined in a co-extruded dosage form. Several thermoplastic polymers were hot-melt extruded and evaluated for processability and macroscopic properties (surface smoothness, die swell). Metoprolol tartrate (MPT) and hydrochlorothiazide (HCT) were incorporated as sustained and immediate release model drugs, respectively. Based on the polymer screening experiments a combination of polycaprolactone (core) and polyethylene oxide (coat) was selected for co-extrusion trials, taking into account their drug release profiles and extrusion temperature (70 °C). This combination (containing 10% HCT in the coat and 45% MPT in the core) was successfully co-extruded (diameter core: 3 mm/thickness coat: 0.5 mm). Adhesion between the two polymer layers was good. HCT release from the coat was complete within 30 min, while MPT release was sustained over 24 h (55%, 70%, 85% and 100% after 4, 8, 12 and 2 4h, respectively). DSC, XRD and Raman spectroscopy revealed that MPT remained crystalline during extrusion, whereas HCT was dissolved in the polyethylene oxide matrix. The in vivo study revealed no significant differences between the experimental formulation and the reference formulation (Zok-Zid tablet). Fixed-dose combination mini-tablets with good in vitro and in vivo performance were successfully developed by means of co-extrusion, using a combination of polycaprolactone and polyethylene oxide. PMID:22504402

  13. Extrusion Die Design and Process Simulation of High Strength Aluminium Alloy

    NASA Astrophysics Data System (ADS)

    Sheu, Jinn-Jong; Chen, Yan-Hong; Su, Guan-Cheng

    2011-01-01

    Aluminium alloy 7075 is an excellent metal with the features of high strength and light weight. The solid extruded parts of AL 7075 are commonly used in the structure members of airplanes and bicycles. The seamless tubes of AL 7075 are also used, while tubes with welding line (seamed) are mainly made by the other types of aluminium alloy. This research is focused on the extrusion die design and process simulation of the rectangular seamed AL 7075 tubes. A new die design concept is proposed to increase the welding pressure in the chamber to solve the problem of poor welding ability of AL 7075. The key points of welding ability improvement are the higher welding pressure, the crucial billet temperature, and the extrusion speed. The designed extrusion die should have some features to control the material flow and achieve the higher welding pressure. In this paper, not only use the traditional die bearing and the welding chamber, but also add a conical guiding chamber (specified with chamber height and width) to improve the material flow control. Finite element method is used to simulate the extrusion process and evaluate the effect of die design parameters for a seamed rectangular 7075 tube extrusion. The die stress should be considered carefully because of increasing the welding pressure also increases the die stress. Taguchi method is used to obtain the optimum combination of die design parameters to get higher welding pressure and keep the die stress at a reasonable low level. The method proposed in this paper is able to increase the welding pressure with the cost of reasonable die stress.

  14. Extent and mechanism of phase separation during the extrusion of calcium phosphate pastes.

    PubMed

    O'Neill, Rory; McCarthy, Helen O; Cunningham, Eoin; Montufar, Edgar; Ginebra, Maria-Pau; Wilson, D Ian; Lennon, Alex; Dunne, Nicholas

    2016-02-01

    The aim of this study was to increase understanding of the mechanism and dominant drivers influencing phase separation during ram extrusion of calcium phosphate (CaP) paste for orthopaedic applications. The liquid content of extrudate was determined, and the flow of liquid and powder phases within the syringe barrel during extrusion were observed, subject to various extrusion parameters. Increasing the initial liquid-to-powder mass ratio, LPR, (0.4-0.45), plunger rate (5-20 mm/min), and tapering the barrel exit (45°-90°) significantly reduced the extent of phase separation. Phase separation values ranged from (6.22 ± 0.69 to 18.94 ± 0.69 %). However altering needle geometry had no significant effect on phase separation. From powder tracing and liquid content determination, static zones of powder and a non-uniform liquid distribution was observed within the barrel. Measurements of extrudate and paste LPR within the barrel indicated that extrudate LPR remained constant during extrusion, while LPR of paste within the barrel decreased steadily. These observations indicate the mechanism of phase separation was located within the syringe barrel. Therefore phase separation can be attributed to either; (1) the liquid being forced downstream by an increase in pore pressure as a result of powder consolidation due to the pressure exerted by the plunger or (2) the liquid being drawn from paste within the barrel, due to suction, driven by dilation of the solids matrix at the barrel exit. Differentiating between these two mechanisms is difficult; however results obtained suggest that suction is the dominant phase separation mechanism occurring during extrusion of CaP paste. PMID:26704546

  15. Using artificial neural networks to model extrusion processes for the manufacturing of polymeric micro-tubes

    NASA Astrophysics Data System (ADS)

    Mekras, N.; Artemakis, I.

    2012-09-01

    In this paper a methodology and an application example are presented aiming to show how Artificial Neural Networks (ANNs) can be used to model manufacturing processes when mathematical models are missing or are not applicable e.g. due to the micro- & nano-scaling, due to non-conventional processes, etc. Besides the ANNs methodology, the results of a Software System developed will be presented, which was used to create ANNs models for micro & nano manufacturing processes. More specifically results of a specific application example will be presented, concerning the modeling of extrusion processes for polymeric micro-tubes. ANNs models are capable for modeling manufacturing processes as far as adequate experimental and/or historical data of processes' inputs & outputs are available for their training. The POLYTUBES ANNs models have been trained and tested with experimental data records of process' inputs and outputs concerning a micro-extrusion process of polymeric micro-tubes for several materials such as: COC, PC, PET, PETG, PP and PVDF. The main ANN model of the extrusion application example has 3 inputs and 9 outputs. The inputs are: tube's inner & outer diameters, and the material density. The model outputs are 9 process parameters, which correspond to the specific inputs e.g. process temperature, die inner & outer diameters, extrusion pressure, draw speed etc. The training of the ANN model was completed, when the errors for the model's outputs, which expressed the difference between the training target values and the ANNs outputs, were minimized to acceptable levels. After the training, the micro-extrusion ANN is capable to simulate the process and can be used to calculate model's outputs, which are the process parameters for any new set of inputs. By this way a satisfactory functional approximation of the whole process is achieved. This research work has been supported by the EU FP7 NMP project POLYTUBES.

  16. Incidence of graft extrusion following minimally invasive transforaminal lumbar interbody fusion.

    PubMed

    Bakhsheshian, Joshua; Khanna, Ryan; Choy, Winward; Lawton, Cort D; Nixon, Alex T; Wong, Albert P; Koski, Tyler R; Liu, John C; Song, John K; Dahdaleh, Nader S; Smith, Zachary A; Fessler, Richard G

    2016-02-01

    Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) has been scrutinized for having a complex learning curve. Careful assessment of MI-TLIF complications and critical analyses of prevention may aid a safe adoption of this technique. The current report focuses on the incidence of interbody cage extrusions following MI-TLIF in a series of 513 patients. The authors discuss their experience with graft extrusions and provide methods to minimize this complication. This study retrospectively reviewed 513 prospectively followed patients who underwent MI-TLIF over a 10 year period. The inclusion criteria consisted of all patients who underwent one to three level MI-TLIF, from whom the incidence of cage extrusion was analyzed. Cage extrusion was defined as an interbody graft migrating outside the cephalad and caudal vertebral body posterior margin. Cage extrusions were diagnosed by comparing the intraoperative radiographs to the postoperative radiographs. Patients with >10° coronal curves, significant sagittal malalignment, infection, and preoperative instrumentation failure were excluded. Of 513 patients undergoing MI-TLIF, five patients (0.97%) were diagnosed with cage migrations. The mean follow-up duration was 13.6 ± standard deviation of 8.8 months. Complications included asymptomatic cage migration alone (two patients) neurological decline (two patients) and epidural hematoma (one patient). On average, cage migrations cost a university hospital an additional $US17,217 for revision treatment. While the incidence of cage migrations is low (0.97%), it can lead to postoperative complications that require revision surgery and increased hospital costs. The risk for this significant complication can be minimized with proper technique and patient selection. PMID:26578209

  17. Low-aluminum-content iron-aluminum alloys

    SciTech Connect

    Sikka, V.K.; Baldwin, R.H.; Howell, C.R.

    1993-07-01

    The low room-temperature ductility Fe{sub 3}Al-based alloys is associated with their environmental embrittlement. Reducing the aluminum level from 29 to 16 at % has been found to be an effective method in essentially eliminating the environmental-embrittlement effect and increasing the room-temperature ductility value to over 25%. This paper will present data on alloy compositions, melting, casting and processing methods, and mechanical properties. Plans for future work on these alloys will also be described.

  18. Reactively Deposited Aluminum Oxide and Fluoropolymer Filled Aluminum Oxide Protective Coatings for Polymers

    NASA Technical Reports Server (NTRS)

    Rutledge, Sharon K.; Banks, Bruce A.; Hunt, Jason

    1995-01-01

    Reactive ion beam sputter deposition of aluminum simultaneous with low energy arrival of oxygen ions at the deposition surface enables the formation of highly transparent aluminum oxide films. Thick (12 200 A), adherent, low stress, reactively deposited aluminum oxide films were found to provide some abrasion resistance to polycarbonate substrates. The reactively deposited aluminum oxide films are also slightly more hydrophobic and more transmitting in the UV than aluminum oxide deposited from an aluminum oxide target. Simultaneous reactive sputter deposition of aluminum along with polytetrafluoroethylene (PTFE Teflon) produces fluoropolymer-filled aluminum oxide films which are lower in stress, about the same in transmittance, but more wetting than reactively deposited aluminum oxide films. Deposition properties, processes and potential applications for these coatings will be discussed.

  19. The effect of high density electric pulses on sintered aluminum 201AB silicon carbide MMC PM compacts during plastic deformation

    NASA Astrophysics Data System (ADS)

    Dariavach, Nader Guseinovich

    The effect of high-density electrical pulses on mechanical and structural properties of sintered aluminum SiC metal-matrix composites, fabricated by standard powder-metallurgy compaction and sintering, was investigated. Three types of phenomena where investigated during transverse rupture testing of the samples: a consolidation effect (increasing of the transverse rupture strength (TRS)), an electroplastic effect (decreasing of the flow stresses), and an increasing of the stress intensity factor by electric pulse application. It was observed, that an increase in the TRS strength of sintered powder metallurgy (PM) aluminum and aluminum metal matrix composite (MMC) compacts is a result of the electric pulse consolidation effect due to non-uniform temperature distribution around the grain boundaries. Three analytical models of the thermal effect of electric pulses on aluminum samples where considered: total temperature change of the sample due to a one electric pulse, one-dimensional steady state model and transient 2D thermal analysis of the temperature distribution around the grain boundary. The 2D transient analysis shows that the temperature rise in the grain boundary of a sintered PM aluminum sample due to an electric pulse can exceed the melting point. At the same time the temperature of the bulk material has an insignificant (<28°C) change. It was found that the electroplastic effect, due to electric pulse application, can account for up to a 40% load drop in aluminum MMC PM compacts. Reduction of flow stresses during plastic deformation could reduce the risk of structural damage, micro-cracks, SiC particle fracture and delamination of the aluminum MMC. These results may find practical application for manufacturing processes such as forging, extrusion, rolling, which involve plastic deformation. It was experimentally proven that a non-uniform temperature distribution around the crack could re-melt the crack tip and increase the strength of the damaged material

  20. Microstructure and Mechanical Properties of AA1235 Aluminum Foil Stocks Produced Directly from Electrolytic Aluminum Melt

    NASA Astrophysics Data System (ADS)

    Xiong, Hanqing; Yu, Kun; Wen, Li; Yao, Sujuan; Dai, Yilong; Wang, Zhifeng

    2016-02-01

    A new process is developed to obtain high-quality AA1235 aluminum foil stocks and to replace the traditional manufacture process. During the new manufacture process, AA1235 aluminum sheets are twin-roll casted directly through electrolytic aluminum melt (EAM), and subsequently the sheets are processed into aluminum foil stocks by cold rolling and annealing. Microstructure and mechanical properties of the AA1235 aluminum sheets produced through such new process are investigated in each state by optimal microscope, scanning electron microscopy, X-ray diffraction, orientation imaging microscopy, transmission electron microscopy, etc. The results show that compared with the traditional AA1235 aluminum foil stocks produced through re-melted aluminum melt (RAM), the amount of impurities is decreased in the EAM aluminum foil stocks. The EAM aluminum foil stock obtains less β-FeSiAl5 phases, but more α-Fe2SiAl8 phases. The elongation of EAM aluminum foil stocks is improved significantly owing to more cubic orientation. Especially, the elongation value of the EAM aluminum foil stocks is approximately 25 pct higher than that of the RAM aluminum foil stocks. As a result, the EAM aluminum foil stocks are at an advantage in increasing the processing performance for the aluminum foils during subsequent processes.

  1. Sperm Chromatin-Induced Ectopic Polar Body Extrusion in Mouse Eggs after ICSI and Delayed Egg Activation

    PubMed Central

    Deng, Manqi; Li, Rong

    2009-01-01

    Meiotic chromosomes in an oocyte are not only a maternal genome carrier but also provide a positional signal to induce cortical polarization and define asymmetric meiotic division of the oocyte, resulting in polar body extrusion and haploidization of the maternal genome. The meiotic chromosomes play dual function in determination of meiosis: 1) organizing a bipolar spindle formation and 2) inducing cortical polarization and assembly of a distinct cortical cytoskeleton structure in the overlying cortex for polar body extrusion. At fertilization, a sperm brings exogenous paternal chromatin into the egg, which induces ectopic cortical polarization at the sperm entry site and leads to a cone formation, known as fertilization cone. Here we show that the sperm chromatin-induced fertilization cone formation is an abortive polar body extrusion due to lack of spindle induction by the sperm chromatin during fertilization. If experimentally manipulating the fertilization process to allow sperm chromatin to induce both cortical polarization and spindle formation, the fertilization cone can be converted into polar body extrusion. This suggests that sperm chromatin is also able to induce polar body extrusion, like its maternal counterpart. The usually observed cone formation instead of ectopic polar body extrusion induced by sperm chromatin during fertilization is due to special sperm chromatin compaction which restrains it from rapid spindle induction and therefore provides a protective mechanism to prevent a possible paternal genome loss during ectopic polar body extrusion. PMID:19787051

  2. Concept Feasibility Report for Using Co-Extrusion to Bond Metals to Complex Shapes of U-10Mo

    SciTech Connect

    Lavender, Curt A.; Paxton, Dean M.; Smith, Mark T.; Soulami, Ayoub; Joshi, Vineet V.; Burkes, Douglas

    2013-12-30

    In support of the Convert Program of the U.S. Department of Energy’s National Nuclear Security Administration (DOE/NNSA) Global Threat Reduction Initiative (GTRI), Pacific Northwest National Laboratory (PNNL) has been investigating manufacturing processes for the uranium-10% molybdenum (U-10Mo) alloy plate fuel for the U.S. high-performance research reactors (USHPRR). This report documents the results of PNNL’s efforts to develop the extrusion process for this concept. The approach to the development of a co-extruded complex-shaped fuel has been described and an extrusion of DU-10Mo was made. The initial findings suggest that given the extrusion forces required for processing U-10Mo, the co-extrusion process can meet the production demands of the USHPRR fuel and may be a viable production method. The development activity is in the early stages and has just begun to identify technical challenges to address details such as dimensional tolerances and shape control. New extrusion dies and roll groove profiles have been developed and will be assessed by extrusion and rolling of U-10Mo during the next fiscal year. Progress on the development and demonstration of the co-extrusion process for flat and shaped fuel is reported in this document

  3. Hermetically Sealed Aluminum Electrolytic Capacitor

    NASA Technical Reports Server (NTRS)

    Alwitt, Robert S.; Liu, Yanming; Elias, William

    1996-01-01

    Aluminum electrolytic capacitors are presently not allowed on NASA missions because they outgas water and organic vapors, as well as H2. As a consequence, for some applications, much larger and heavier packages of tantalum capacitors must be used. A hermetically sealed aluminum capacitor has been developed. This contains a nongassing electrolyte that was developed for this application so internal pressure would remain low. Capacitors rated from 250 V to 540 V have been operated under full load for thousands of hours at 85 and 105 C with good electrical performance and absence of gas generation. Electrolyte chemistry and seal engineering will be discussed, as well as the extension of this design concept to lower voltage ratings.

  4. Implants of aluminum into silicon

    NASA Astrophysics Data System (ADS)

    Galvagno, G.; Scandurra, A.; Raineri, V.; Rimini, E.; La Ferla, A.; Sciascia, V.; Frisina, F.; Raspagliesi, M.; Ferla, G.

    1993-04-01

    The electrical behaviour of ion implanted aluminum into silicon was investigated by varying the beam energy in the 80 keV-6 MeV range, the dose in the 1 × 10 13-1 × 10 14/cm 2 range and the annealing procedure. Aluminum atoms precipitate into exten defects at the end of range damage and where the concentration exceeds the solid solubility value (about 2 × 10 19/cm 3 at 1200°C Escape of Al atoms occurs very easily as soon as they reach the external surface during the thermal diffusion. Using high energy implants, 6 MeV, it was possible to follow in detail the broadening of the diffused profiles. The measured trends between the retained dose and the junction depth and between the outdiffused dose and the annealing time are quite well predicted by the solution of the diffusion equation with the surface acting as a perfect sink for the dopant.

  5. Automated and aluminum welding technology

    NASA Astrophysics Data System (ADS)

    Jones, Clyde S.

    1994-10-01

    Automated welding technology and techniques for welding advanced aluminum alloys with potential for industrial and commercial applications have been developed by the National Aeronautics and Space Administration at the Marshall Space Flight Center. These technologies are being offered to private companies for commercial development, and include: Variable polarity plasma arc welding, a welding process that produces high-quality aluminum welds for fabrication of the space shuttle external tank and space station common module structures. This process uses reverse polarity pulses to produce welds virtually free of internal defects. Advanced weld sensor technology, comprised of machine vision-based weld seam tracking that uses both structured and global laser illumination for finding weld joints, even those difficult to discern by the human eye. Weld pool feedback is accomplished with a vision system to measure arc symmetry and molten weld pool geometry. A weld bead profiler trails the welding torch. It provides feedback to the process control system, which records quality control data.

  6. MHD technology in aluminum casting

    SciTech Connect

    Kalinichenko, I.

    1984-08-01

    The use of MHD technology in aluminum casting is discussed. Associates of the Latvian Academy of Sciences Institute of Physics developed magnetohydrodynamic units for the Siberian plant. A MHD unit made it possible to free five persons from heavy work at the plant. Labor productivity doubled in this section. With the aid of the magnetic field, the alloy silumin is obtained in only three hours. Specialists of the Irkutsk affiliate of the All-Union Scientific Research and Design Institute of the Aluminum, Magnesium and Electrode Industry are convinced that MHD technology has a bright future. However, this will necessitate the development of new MHD technology for different types of casting facilities, with their specific features taken into account.

  7. Electrically Conductive Anodized Aluminum Surfaces

    NASA Technical Reports Server (NTRS)

    Nguyen, Trung Hung

    2006-01-01

    Anodized aluminum components can be treated to make them sufficiently electrically conductive to suppress discharges of static electricity. The treatment was conceived as a means of preventing static electric discharges on exterior satin-anodized aluminum (SAA) surfaces of spacecraft without adversely affecting the thermal-control/optical properties of the SAA and without need to apply electrically conductive paints, which eventually peel off in the harsh environment of outer space. The treatment can also be used to impart electrical conductivity to anodized housings of computers, medical electronic instruments, telephoneexchange equipment, and other terrestrial electronic equipment vulnerable to electrostatic discharge. The electrical resistivity of a typical anodized aluminum surface layer lies between 10(exp 11) and 10(exp 13) Omega-cm. To suppress electrostatic discharge, it is necessary to reduce the electrical resistivity significantly - preferably to < or = 10(exp 9) Omega-cm. The present treatment does this. The treatment is a direct electrodeposition process in which the outer anodized surface becomes covered and the pores in the surface filled with a transparent, electrically conductive metal oxide nanocomposite. Filling the pores with the nanocomposite reduces the transverse electrical resistivity and, in the original intended outer-space application, the exterior covering portion of the nanocomposite would afford the requisite electrical contact with the outer-space plasma. The electrical resistivity of the nanocomposite can be tailored to a value between 10(exp 7) and 10(exp 12) Omega-cm. Unlike electrically conductive paint, the nanocomposite becomes an integral part of the anodized aluminum substrate, without need for adhesive bonding material and without risk of subsequent peeling. The electrodeposition process is compatible with commercial anodizing production lines. At present, the electronics industry uses expensive, exotic

  8. Aluminum-lithium target behavior

    SciTech Connect

    McDonell, W.R.

    1989-10-01

    Information on physical properties and irradiation behavior of aluminum-lithium target alloys employed for the production of tritium in Savannah River reactors has been reviewed to support development of technology for the New Production Reactor (NPR). Phase compositions and microstructures, thermal conductivity, mechanical properties, and constituent diffusion phenomena of the alloys, established in prior site studies, are presented. Irradiation behavior, including distributions of product tritium and helium and related exposure limits due to swelling and cracking of the target alloys is discussed, along with gas release processes occurring during subsequent product recovery operations. The property review supports designation of the aluminum-lithium alloys as ideally well-suited target materials for low-temperature, tritium-producing reactors, demonstrated over 35 years of Savannah River reactor operation. Low temperature irradiation and reaction with lithium in the alloy promotes tritium retention during reactor exposure, and the aluminum provides a matrix from which the product is readily recovered on heating following irradiation. 33 refs., 26 figs., 8 tabs.

  9. Microbial corrosion of aluminum alloy.

    PubMed

    Yang, S S; Chen, C Y; Wei, C B; Lin, Y T

    1996-11-01

    Several microbes were isolated from the contaminated fuel-oil in Taiwan and the microbial corrosion of aluminum alloy A356-T6 was tested by MIL-STD-810E test method. Penicillium sp. AM-F5 and Cladosporium resinac ATCC 22712 had significant adsorption and pitting on the surface of aluminum alloy, Pseudomonas acruginosa AM-B5 had weak adsorption and some precipitation in the bottom, and Candida sp. AM-Y1 had the less adsorption and few cavities formation on the surface. pH of the aqueous phase decreased 0.3 to 0.7 unit for 4 months of incubation. The corrosion of aluminum alloy was very significant in the cultures of Penicillium sp. AM-F2, Penicillium sp. AM-F5 and C. resinac ATCC 22712. The major metabolites in the aqueous phase with the inoculation of C. resinac were citric acid and oxalic acid, while succinic acid and fumaric acid were the minors. PMID:10592801

  10. The Effect of Impurities on the Processing of Aluminum Alloys

    SciTech Connect

    Zi-Kui Liu; Shengjun Zhang; Qingyou Han; Vinod Sikka

    2007-04-23

    database developed in this project, thermodynamic simulations were carried out to investigate the effect of sodium on the HTE of Al-Mg alloys. The simulation results indicated that the liquid miscibility gap resulting from the dissolved sodium in the molten material plays an important role in HTE. A liquid phase forms from the solid face-centered cubic (fcc) phase (most likely at grain boundaries) during cooling, resulting in the occurrence of HTE. Comparison of the thermodynamic simulation results with experimental measurements on the high-temperature ductility of an Al-5Mg-Na alloy shows that HTE occurs in the temperature range at which the liquid phase exists. Based on this fundamental understanding of the HTE mechanism during processing of aluminum alloy, an HTE sensitive zone and a hot-rolling safe zone of the Al-Mg-Na alloys are defined as functions of processing temperature and alloy composition. The tendency of HTE was evaluated based on thermodynamic simulations of the fraction of the intergranular sodium-rich liquid phase. Methods of avoiding HTE during rolling/extrusion of Al-Mg-based alloys were suggested. Energy and environmental benefits from the results of this project could occur through a number of avenues: (1) energy benefits accruing from reduced rejection rates of the aluminum sheet and bar, (2) reduced dross formation during the remelting of the aluminum rejects, and (3) reduced CO2 emission related to the energy savings. The sheet and extruded bar quantities produced in the United States during 2000 were 10,822 and 4,546 million pounds, respectively. It is assumed that 50% of the sheet and 10% of the bar will be affected by implementing the results of this project. With the current process, the rejection rate of sheet and bar is estimated at 5%. Assuming that at least half of the 5% rejection of sheet and bar will be eliminated by using the results of this project and that 4% of the aluminum will be lost through dross (Al2O3) during remelting of the

  11. A new dual-plate slipometer for measuring slip between molten polymers and extrusion die materials

    NASA Astrophysics Data System (ADS)

    Schmalzer, A. M.; Giacomin, A. J.

    2014-04-01

    In this work, we study the slip behaviors common to plastics die extrusion metals or platings using a new instrument called a dual-plate slipometer. By dual-plate, we mean that whereas the stationary plate incorporates a local shear stress transducer, the moving plate does not. The stationary plate and transducer are made of one stainless steel, but the moving plate is made from, or plated with, different extrusion die materials under study. This new instrument allows slip velocity to be measured without having to build a new shear stress transducer from each extrusion metal or plating under study. We explore the effect of extrusion die composition and die metal surface morphology on the slip properties of polyolefins using a sliding plate rheometer. In this work, we studied the slip behaviors of polyolefins on four common plastics die extrusion metals or platings, without having to build a new shear stress transducer from each. Specifically, our new method replaces the moving plate; with each of the four die metals or platings under study without changing the stainless steel material of the shear stress transducer and its stationary plate. Our experiments include high-density polyethylene, low-density polyethylene, and polypropylene (PP) on four different die metals or platings. We use steady simple shear to obtain shear stress versus nominal shear rate for different gaps, from which we can then deduce the slip velocity using the Mooney analysis. We then fit four slip models to our experimental measurements, and we find the Hatzikiriakos hyperbolic sine model to be accurate, even for the measured inflections in the slip velocity as a function of shear stress curves. Our analysis includes detailed characterization of the die metal plating surfaces, including measurements of the composition of the sliding plates by energy dispersive spectroscopy, surface energy by contact angle goniometry, and surface roughness by both white light interference and stylus

  12. Oceanic corrosion test of bare and zinc-protected aluminum alloys for seawater heat exchangers

    NASA Technical Reports Server (NTRS)

    Sasscer, D. S.; Morgan, T. O.; Rivera, C.; Ernst, R.; Scott, A. C.; Summerson, T. J.

    1982-01-01

    Bare 3004 tubes, 7072 Alclad 3004 tubes, and bare and zinc diffusion treated 3003 extrusions from a brazed aluminum, plate-fin heat exchanger were exposed to 1.8 m/sec flowing seawater aboard an open ocean test facility moored 3.4 km off the southeast coast of Puerto Rico. After six months exposure, the average corrosion rates for most varieties of aluminum materials converged to a low value of 0.015 mm/yr (0.6 mils/yr). Pitting did not occur in bare 3003 and 3004 samples during the six month test. Pitting did occur to varying degrees in the Alclad and zinc diffusion treated material, but did not penetrate to the base metal. Biofouling countermeasures (intermittent chlorination and brushing) did not affect the corrosion rates to any significant extent. Intermittent chlorination at a level of 0.5 ppm for 28 minutes daily controlled microbiofouling of the samples but did not prevent the development of a macrobiofouling community in areas of the plumbing with low flow.

  13. Brassica oleracea MATE encodes a citrate transporter and enhances aluminum tolerance in Arabidopsis thaliana.

    PubMed

    Wu, Xinxin; Li, Ren; Shi, Jin; Wang, Jinfang; Sun, Qianqian; Zhang, Haijun; Xing, Yanxia; Qi, Yan; Zhang, Na; Guo, Yang-Dong

    2014-08-01

    The secretion of organic acid anions from roots is an important mechanism for plant aluminum (Al) tolerance. Here we report cloning and characterizing BoMATE (KF031944), a multidrug and toxic compound extrusion (MATE) family gene from cabbage (Brassica oleracea). The expression of BoMATE was more abundant in roots than in shoots, and it was highly induced by Al treatment. The (14)C-citrate efflux experiments in oocytes demonstrated that BoMATE is a citrate transporter. Electrophysiological analysis and SIET analysis of Xenopus oocytes expressing BoMATE indicated BoMATE is activated by Al. Transient expression of BoMATE in onion epidermal cells demonstrated that it localized to the plasma membrane. Compared with the wild-type Arabidopsis, the transgenic lines constitutively overexpressing BoMATE enhanced Al tolerance and increased citrate secretion. In addition, Arabidopsis transgenic lines had a lower K(+) efflux and higher H(+) efflux, in the presence of Al, than control wild type in the distal elongation zone (DEZ). This is the first direct evidence that MATE protein is involved in the K(+) and H(+) flux in response to Al treatment. Taken together, our results show that BoMATE is an Al-induced citrate transporter and enhances aluminum tolerance in Arabidopsis thaliana. PMID:24850836

  14. Production of anhydrous aluminum chloride composition

    DOEpatents

    Vandergrift, G.F. III; Krumpelt, M.; Horwitz, E.P.

    1981-10-08

    A process is described for producing an anhydrous aluminum chloride composition from a water-based aluminous material such as a slurry of aluminum hydroxide in a multistage extraction process in which the aluminum ion is first extracted into an organic liquid containing an acidic extractant and then extracted from the organic phase into an alkali metal chloride or chlorides to form a melt containing a mixture of chlorides of alkali metal and aluminum. In the process, the organic liquid may be recycled. In addition, the process advantageously includes an electrolysis cell for producing metallic aluminum and the alkali metal chloride or chlorides may be recycled for extraction of the aluminum from the organic phase.

  15. PREPARATION OF ACTINIDE-ALUMINUM ALLOYS

    DOEpatents

    Moore, R.H.

    1962-09-01

    BS>A process is given for preparing alloys of aluminum with plutonium, uranium, and/or thorium by chlorinating actinide oxide dissolved in molten alkali metal chloride with hydrochloric acid, chlorine, and/or phosgene, adding aluminum metal, and passing air and/or water vapor through the mass. Actinide metal is formed and alloyed with the aluminum. After cooling to solidification, the alloy is separated from the salt. (AEC)

  16. FT-IR Study Of Chemical Changes, Occuring During Co-Extrusion Pulverization Of LDPE With Styrene-Butadiene Rubber

    NASA Astrophysics Data System (ADS)

    Vladimirov, Leonid V.

    1989-12-01

    The chemical structure changes in polymers under conditions of molding, extrusion, or other fabrication techniques can be important factors affecting the macroscopic properties and applications of the resulting materials.

  17. Influence of Shock Prestraining and Grain Size on the Dynamic Tensile Extrusion Response of Copper: Experiments, Modeling and Simulation

    NASA Astrophysics Data System (ADS)

    Gray, George, III

    2005-07-01

    The mechanical behavior and damage evolution response of high-purity Cu are influenced by strain rate, temperature, stress state, grain size, and shock prestraining. The effects of grain size on the mechanical response of high-purity Cu have been probed and are correlated with the substructural evolution during deformation. The dynamic extrusion response of shock prestrained Cu demonstrates the significant influence of grain size on the large-strain dynamic tensile ductility of high-purity copper. Eulerian hydrocode simulations utilizing the Mechanical Threshold Stress flow stress model were performed to provide insight into the dynamic extrusion process. Quantitative comparisons between the predicted and measured deformation topologies and extrusion rate will be presented. Predictions of the texture evolution (based upon the deformation rate history and the rigid body rotations experienced by the Cu during the extrusion process) are compared with texture measurements.

  18. Reducing corrosion in aluminum-steel joints

    SciTech Connect

    Not Available

    1994-01-01

    This article examines how galvanic corrosion in aluminum-intensive steel structures can be controlled, without losing performance, by using transition materials. The topics of the article include the transition material concept, corrosion resistance, experimental conditions, and the results of the experiment including mass loss of lap joints, strength retention, joining methods. The results show how use of steel-clad aluminum transition material in joining aluminum and steel deals successfully addresses the problems of joining and durability associated with increasing use of aluminum on automobiles.

  19. Aluminum-stabilized NB3SN superconductor

    DOEpatents

    Scanlan, Ronald M.

    1988-01-01

    An aluminum-stabilized Nb.sub.3 Sn superconductor and process for producing same, utilizing ultrapure aluminum. Ductile components are co-drawn with aluminum to produce a conductor suitable for winding magnets. After winding, the conductor is heated to convert it to the brittle Nb.sub.3 Sn superconductor phase, using a temperature high enough to perform the transformation but still below the melting point of the aluminum. This results in reaction of substantially all of the niobium, while providing stabilization and react-in-place features which are beneficial in the fabrication of magnets utilizing superconducting materials.

  20. Gut: An underestimated target organ for Aluminum.

    PubMed

    Vignal, C; Desreumaux, P; Body-Malapel, M

    2016-06-01

    Since World War II, several factors such as an impressive industrial growth, an enhanced environmental bioavailability and intensified food consumption have contributed to a significant amplification of human exposure to aluminum. Aluminum is particularly present in food, beverages, some drugs and airbone dust. In our food, aluminum is superimposed via additives and cooking utensils. Therefore, the tolerable intake of aluminum is exceeded for a significant part of the world population, especially in children who are more vulnerable to toxic effects of pollutants than adults. Faced with this oral aluminum influx, intestinal tract is an essential barrier, especially as 38% of ingested aluminum accumulates at the intestinal mucosa. Although still poorly documented to date, the impact of oral exposure to aluminum in conditions relevant to real human exposure appears to be deleterious for gut homeostasis. Aluminum ingestion affects the regulation of the permeability, the microflora and the immune function of intestine. Nowadays, several arguments are consistent with an involvement of aluminum as an environmental risk factor for inflammatory bowel diseases. PMID:26970682