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Sample records for formation confers aluminum

  1. A Formate Dehydrogenase Confers Tolerance to Aluminum and Low pH1[OPEN

    PubMed Central

    Gong, Yu Long; Fan, Wei; Xu, Jia Meng; Liu, Yu; Cao, Meng Jie; Wang, Ming-Hu

    2016-01-01

    Formate dehydrogenase (FDH) is involved in various higher plant abiotic stress responses. Here, we investigated the role of rice bean (Vigna umbellata) VuFDH in Al and low pH (H+) tolerance. Screening of various potential substrates for the VuFDH protein demonstrated that it functions as a formate dehydrogenase. Quantitative reverse transcription-PCR and histochemical analysis showed that the expression of VuFDH is induced in rice bean root tips by Al or H+ stresses. Fluorescence microscopic observation of VuFDH-GFP in transgenic Arabidopsis plants indicated that VuFDH is localized in the mitochondria. Accumulation of formate is induced by Al and H+ stress in rice bean root tips, and exogenous application of formate increases internal formate content that results in the inhibition of root elongation and induction of VuFDH expression, suggesting that formate accumulation is involved in both H+- and Al-induced root growth inhibition. Over-expression of VuFDH in tobacco (Nicotiana tabacum) results in decreased sensitivity to Al and H+ stress due to less production of formate in the transgenic tobacco lines under Al and H+ stresses. Moreover, NtMATE and NtALS3 expression showed no changes versus wild type in these over-expression lines, suggesting that herein known Al-resistant mechanisms are not involved. Thus, the increased Al tolerance of VuFDH over-expression lines is likely attributable to their decreased Al-induced formate production. Taken together, our findings advance understanding of higher plant Al toxicity mechanisms, and suggest a possible new route toward the improvement of plant performance in acidic soils, where Al toxicity and H+ stress coexist. PMID:27021188

  2. A Formate Dehydrogenase Confers Tolerance to Aluminum and Low pH.

    PubMed

    Lou, He Qiang; Gong, Yu Long; Fan, Wei; Xu, Jia Meng; Liu, Yu; Cao, Meng Jie; Wang, Ming-Hu; Yang, Jian Li; Zheng, Shao Jian

    2016-05-01

    Formate dehydrogenase (FDH) is involved in various higher plant abiotic stress responses. Here, we investigated the role of rice bean (Vigna umbellata) VuFDH in Al and low pH (H(+)) tolerance. Screening of various potential substrates for the VuFDH protein demonstrated that it functions as a formate dehydrogenase. Quantitative reverse transcription-PCR and histochemical analysis showed that the expression of VuFDH is induced in rice bean root tips by Al or H(+) stresses. Fluorescence microscopic observation of VuFDH-GFP in transgenic Arabidopsis plants indicated that VuFDH is localized in the mitochondria. Accumulation of formate is induced by Al and H(+) stress in rice bean root tips, and exogenous application of formate increases internal formate content that results in the inhibition of root elongation and induction of VuFDH expression, suggesting that formate accumulation is involved in both H(+)- and Al-induced root growth inhibition. Over-expression of VuFDH in tobacco (Nicotiana tabacum) results in decreased sensitivity to Al and H(+) stress due to less production of formate in the transgenic tobacco lines under Al and H(+) stresses. Moreover, NtMATE and NtALS3 expression showed no changes versus wild type in these over-expression lines, suggesting that herein known Al-resistant mechanisms are not involved. Thus, the increased Al tolerance of VuFDH over-expression lines is likely attributable to their decreased Al-induced formate production. Taken together, our findings advance understanding of higher plant Al toxicity mechanisms, and suggest a possible new route toward the improvement of plant performance in acidic soils, where Al toxicity and H(+) stress coexist. PMID:27021188

  3. 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

  4. Nanostructure of aluminum oxide inclusion and formation of hydrogen bubbles in molten aluminum.

    PubMed

    Zeng, Jianmin; Li, Dezhi; Kang, Minglong; He, Huan; Hu, Zhiliu

    2013-10-01

    Hydrogen in molten aluminum is one of the major factors that lead to pore formation in the solidification process of aluminum castings. Previous research showed that aluminum oxide inclusion had a close correlation with the hydrogen content in molten aluminum. Though some researchers thought there must have been a relationship between surface morphology of the inclusion and hydrogen concentration in molten aluminum, very few documents have reported on the surface property of aluminum oxide inclusion. In the present work, AFM (Atomic Force Microscope) was first used to investigate surface morphology of aluminum oxide inclusion in molten aluminum. It was found that there were a large number of nanoscale micropores on the surface of aluminum oxide inclusion. The interior of the micropores was approximated as a tapered shape. These micropores were thought to be helpful to heterogeneous nucleation for hydrogen atoms aggregation because they provided necessary concentration fluctuation and energy undulation for the growth of hydrogen bubbles. Based on the nanostructure observed on the surface of aluminum oxide inclusion, a theoretical model was developed to describe the hydrogen pore formation in aluminum casting under the condition of heterogeneous nucleation.

  5. Energetic Insight into the Formation of Solids from Aluminum Polyoxocations.

    PubMed

    Reusser, Dana; Casey, William H; Navrotsky, Alexandra

    2015-08-01

    The ε-Keggin [AlO4Al12(OH)24(H2O)12](7+) ion (AlAl12(7+)) is a metastable precursor in the formation of aluminum oxyhydroxide solids. It also serves as a useful model for the chemistry of aluminous mineral surfaces. Herein we calculate the enthalpies of formation for this aqueous ion and its heterometal-substituted forms, GaAl12(7+) and GeAl12(8+), using solution calorimetry. Rather than measuring the enthalpies of the MAl12(7/8+) ions directly from solution hydrolysis, we measured the metathesis reaction of the crystallized forms with barium chloride creating an aqueous aluminum solution monospecific in MAl12(7/8+). Then, the contributions to the heat of formation from the crystallized forms were subtracted using referenced states. When comparing the aqueous AlAl12(7+) ion to solid aluminum (oxy)-hydroxide phases, we found that this ion lies closer in energy to solid phases than to aqueous aluminum monomers, thus explaining its role as a precursor to amorphous aluminum hydroxide phases. PMID:26129924

  6. Chromosome-anchored QTL conferring aluminum tolerance in hexaploid oat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Abstract Aluminum (Al) toxicity is a major constraint on crop production in acid soils around the world. Hexaploid oat (Avena sativa L.) possesses signi'cant Al tolerance making it a good candidate for production in these environments. Genetic improvement for Al tolerance in oat has traditionally be...

  7. Electrochemical formation of a composite polymer-aluminum oxide film

    NASA Astrophysics Data System (ADS)

    Runge-Marchese, Jude Mary

    1997-10-01

    The formation of polymer films through electrochemical techniques utilizing electrolytes which include conductive polymer is of great interest to the coatings and electronics industries as a means for creating electrically conductive and corrosion resistant finishes. One of these polymers, polyamino-benzene (polyaniline), has been studied for this purpose for over ten years. This material undergoes an insulator-to-metal transition upon doping with protonic acids in an acid/base type reaction. Review of prior studies dealing with polyaniline and working knowledge of aluminum anodization has led to the development of a unique process whereby composite polymer-aluminum oxide films are formed. The basis for the process is a modification of the anodizing electrolyte which results in the codeposition of polyaniline during aluminum anodization. A second process, which incorporates electrochemical sealing of the anodic layer with polyaniline was also developed. The formation of these composite films is documented through experimental processing, and characterized by way of scientific analysis and engineering tests. Analysis results revealed the formation of unique dual phase anodic films with fine microstructures which exhibited full intrusion of the columnar aluminum oxide structure with polyaniline, indicating the polymer was deposited as the metal oxidation proceeded. An aromatic amine derivative of polyaniline with aluminum sulfate was determined to be the reaction product within the aluminum oxide phase of the codeposited films. Scientific characterization determined the codeposition process yields completely chemically and metallurgically bound composite films. Engineering studies determined the films, obtained through a single step, exhibited superior wear and corrosion resistance to conventionally anodized and sealed films processed through two steps, demonstrating the increased manufacturing process efficiency that can be realized with the modification of the

  8. Self-assembly formation of lipid bilayer coatings on bare aluminum oxide: overcoming the force of interfacial water.

    PubMed

    Jackman, Joshua A; Tabaei, Seyed R; Zhao, Zhilei; Yorulmaz, Saziye; Cho, Nam-Joon

    2015-01-14

    Widely used in catalysis and biosensing applications, aluminum oxide has become popular for surface functionalization with biological macromolecules, including lipid bilayer coatings. However, it is difficult to form supported lipid bilayers on aluminum oxide, and current methods require covalent surface modification, which masks the interfacial properties of aluminum oxide, and/or complex fabrication techniques with specific conditions. Herein, we addressed this issue by identifying simple and robust strategies to form fluidic lipid bilayers on aluminum oxide. The fabrication of a single lipid bilayer coating was achieved by two methods, vesicle fusion under acidic conditions and solvent-assisted lipid bilayer (SALB) formation under near-physiological pH conditions. Importantly, quartz crystal microbalance with dissipation (QCM-D) monitoring measurements determined that the hydration layer of a supported lipid bilayer on aluminum oxide is appreciably thicker than that of a bilayer on silicon oxide. Fluorescence recovery after photobleaching (FRAP) analysis indicated that the diffusion coefficient of lateral lipid mobility was up to 3-fold greater on silicon oxide than on aluminum oxide. In spite of this hydrodynamic coupling, the diffusion coefficient on aluminum oxide, but not silicon oxide, was sensitive to the ionic strength condition. Extended-DLVO model calculations estimated the thermodynamics of lipid-substrate interactions on aluminum oxide and silicon oxide, and predict that the range of the repulsive hydration force is greater on aluminum oxide, which in turn leads to an increased equilibrium separation distance. Hence, while a strong hydration force likely contributes to the difficulty of bilayer fabrication on aluminum oxide, it also confers advantages by stabilizing lipid bilayers with thicker hydration layers due to confined interfacial water. Such knowledge provides the basis for improved surface functionalization strategies on aluminum oxide

  9. Self-assembly formation of lipid bilayer coatings on bare aluminum oxide: overcoming the force of interfacial water.

    PubMed

    Jackman, Joshua A; Tabaei, Seyed R; Zhao, Zhilei; Yorulmaz, Saziye; Cho, Nam-Joon

    2015-01-14

    Widely used in catalysis and biosensing applications, aluminum oxide has become popular for surface functionalization with biological macromolecules, including lipid bilayer coatings. However, it is difficult to form supported lipid bilayers on aluminum oxide, and current methods require covalent surface modification, which masks the interfacial properties of aluminum oxide, and/or complex fabrication techniques with specific conditions. Herein, we addressed this issue by identifying simple and robust strategies to form fluidic lipid bilayers on aluminum oxide. The fabrication of a single lipid bilayer coating was achieved by two methods, vesicle fusion under acidic conditions and solvent-assisted lipid bilayer (SALB) formation under near-physiological pH conditions. Importantly, quartz crystal microbalance with dissipation (QCM-D) monitoring measurements determined that the hydration layer of a supported lipid bilayer on aluminum oxide is appreciably thicker than that of a bilayer on silicon oxide. Fluorescence recovery after photobleaching (FRAP) analysis indicated that the diffusion coefficient of lateral lipid mobility was up to 3-fold greater on silicon oxide than on aluminum oxide. In spite of this hydrodynamic coupling, the diffusion coefficient on aluminum oxide, but not silicon oxide, was sensitive to the ionic strength condition. Extended-DLVO model calculations estimated the thermodynamics of lipid-substrate interactions on aluminum oxide and silicon oxide, and predict that the range of the repulsive hydration force is greater on aluminum oxide, which in turn leads to an increased equilibrium separation distance. Hence, while a strong hydration force likely contributes to the difficulty of bilayer fabrication on aluminum oxide, it also confers advantages by stabilizing lipid bilayers with thicker hydration layers due to confined interfacial water. Such knowledge provides the basis for improved surface functionalization strategies on aluminum oxide

  10. Enthalpy of the formation of natural hydrous aluminum hydroxosulfate (aluminite)

    NASA Astrophysics Data System (ADS)

    Ogorodova, L. P.; Nagornaya, E. V.; Mel'chakova, L. V.; Vigasina, M. F.; Baksheev, I. A.

    2013-12-01

    A thermochemical study of natural aluminum hydroxosulfate Al2[(OH)4SO4] · 7H2O, aluminite (Nakhodka deposit, West Chukotka, Russia) is performed on a Tian-Calvet "Setaram" high-temperature heat-conducting microcalorimeter (France). The enthalpy of aluminite formation from simple compounds is obtained via the melt calorimetry of dissolution, Δf H ○(298.15 K) = -4986 ± 21 kJ/mol.

  11. Formation of Anodic Aluminum Oxide with Branched and Meshed Pores.

    PubMed

    Kim, Byeol; Lee, Jin Seok

    2016-06-01

    Anodic aluminum oxide (AAO), with a self-ordered hexagonal array, is important for various applications in nanofabrication including as the fabrication of nanotemplates and other nanostructures. With the consideration, there have been many efforts to control the characteristic parameters of porous anodic alumina by adjustment of the anodizing conditions such as the electrolyte, temperature, applied potential, and Al purity. In particular, impurities in Al are changing the morphology of an alumina film; however, the formation mechanism has not yet been explained. In this work, we anodized a high purity (99.999%, Al(high)) and low purity (99.8%, Al(low)) aluminum foil by a two-step anodization process in an oxalic acid solution or phosphoric acid. It was found that the purity of aluminum foil has influenced the morphology of the alumina film resulting in branched and meshed pores. Also, electrochemical analysis indicated that the branched and meshed pores in the low-purity Al foil formed by the presence of impurities. Impurities act as defects and change the general growth mechanism for pore formation by inducing an electric field imbalance during anodization. This work contributes to the research field of topographical chemistry and applied fields including nanofabrication. PMID:27427755

  12. Formation of anodic aluminum oxide with serrated nanochannels.

    PubMed

    Li, Dongdong; Zhao, Liang; Jiang, Chuanhai; Lu, Jia G

    2010-08-11

    We report a simple and robust method to self-assemble porous anodic aluminum oxide membranes with serrated nanochannels by anodizing in phosphoric acid solution. Due to high field conduction and anionic incorporation, an increase of anodizing voltage leads to an increase of the impurity levels and also the field strength across barrier layer. On the basis of both experiment and simulation results, the initiation and formation of serrated channels are attributed to the evolution of oxygen gas bubbles followed by plastic deformation in the oxide film. Alternating anodization in oxalic and phosphoric acids is applied to construct multilayered membranes with smooth and serrated channels, demonstrating a unique way to design and construct a three-dimensional hierarchical system with controllable morphology and composition. PMID:20617804

  13. Facile formation of superhydrophobic aluminum alloy surface and corrosion-resistant behavior

    NASA Astrophysics Data System (ADS)

    Feng, Libang; Yan, Zhongna; Qiang, Xiaohu; Liu, Yanhua; Wang, Yanping

    2016-03-01

    Superhydrophobic surface with excellent corrosion resistance was prepared on aluminum alloy via boiling water treatment and surface modification with stearic acid. Results suggested that the micro- and nanoscale hierarchical structure along with the hydrophobic chemical composition surface confers the aluminum alloy surface with good superhydrophobicity, and the water contact angle and the water sliding angle can reach 156.6° and 3°, respectively. The corrosion resistance of the superhydrophobic aluminum alloy was first characterized by potentiodynamic polarization, and then the long-term corrosion resistance was investigated by immersing the sample in NaCl solution for 90 days. The surface wettability, morphology, and composition before and after immersion were examined, and results showed that the superhydrophobic aluminum alloy surface possessed good corrosion resistance under the experimental conditions, which is favorable for its practical application as an engineering material in seawater corrosion conditions. Finally, the mechanism of the superhydrophobicity and excellent corrosion resistance is deduced.

  14. Bifilm Defect Formation in Hydraulic Jump of Liquid Aluminum

    NASA Astrophysics Data System (ADS)

    Hsu, Fu-Yuan

    2016-06-01

    In aluminum gravity casting, as liquid aluminum fell through a vertical sprue and impacted on the horizontal flat surface, a phenomenon known as hydraulic jump ( i.e., flow transition from super-critical to sub-critical flows) was observed. As the jump was transformed, a reverse eddy motion on the surface of the jump was created. This motion entrained aluminum oxide film from the surface into aluminum melt. This folded film (so-called "bifilm" defect) was engulfed by the melt and caused its quality to deteriorate. To understand this phenomenon, aluminum casting experiments and computational modeling were conducted. In the casting experiment, a radius ( R j) to the point where the circular hydraulic jump occurred was measured. This is the circular region of `irregular surface feature', a rough oxidized surface texture near the center area of the castings. To quantify contents of the bifilm defects in the outer region of the jump, the samples in this region were sectioned and re-melted for doing re-melted reduced pressure test (re-melt RPT). An "area-normalized" bifilm index map was plotted to analyze bifilms' population in the samples. The flow transition in the hydraulic jump of liquid aluminum depended on three pressure heads: inertial, gravitational, and surface-tension pressures. A new theoretical equation containing surface tension for describing the flow transition of liquid metal was proposed.

  15. Polyphenol-Aluminum Complex Formation: Implications for Aluminum Tolerance in Plants.

    PubMed

    Zhang, Liangliang; Liu, Ruiqiang; Gung, Benjamin W; Tindall, Steven; Gonzalez, Javier M; Halvorson, Jonathan J; Hagerman, Ann E

    2016-04-20

    Natural polyphenols may play an important role in aluminum detoxification in some plants. We examined the interaction between Al(3+) and the purified high molecular weight polyphenols pentagalloyl glucose (940 Da) and oenothein B (1568 Da), and the related compound methyl gallate (184 Da) at pH 4 and 6. We used spectrophotometric titration and chemometric modeling to determine stability constants and stoichiometries for the aluminum-phenol (AlL) complexes. The structures and spectral features of aluminum-methyl gallate complexes were evaluated with quantum chemical calculations. The high molecular weight polyphenols formed Al3L2 complexes with conditional stability constants (β) ∼ 1 × 10(23) at pH 6 and AlL complexes with β ∼ 1 × 10(5) at pH 4. Methyl gallate formed AlL complexes with β = 1 × 10(6) at pH 6 but did not complex aluminum at pH 4. At intermediate metal-to-polyphenol ratios, high molecular weight polyphenols formed insoluble Al complexes but methyl gallate complexes were soluble. The high molecular weight polyphenols have high affinities and solubility features that are favorable for a role in aluminum detoxification in the environment.

  16. Polyphenol-Aluminum Complex Formation: Implications for Aluminum Tolerance in Plants.

    PubMed

    Zhang, Liangliang; Liu, Ruiqiang; Gung, Benjamin W; Tindall, Steven; Gonzalez, Javier M; Halvorson, Jonathan J; Hagerman, Ann E

    2016-04-20

    Natural polyphenols may play an important role in aluminum detoxification in some plants. We examined the interaction between Al(3+) and the purified high molecular weight polyphenols pentagalloyl glucose (940 Da) and oenothein B (1568 Da), and the related compound methyl gallate (184 Da) at pH 4 and 6. We used spectrophotometric titration and chemometric modeling to determine stability constants and stoichiometries for the aluminum-phenol (AlL) complexes. The structures and spectral features of aluminum-methyl gallate complexes were evaluated with quantum chemical calculations. The high molecular weight polyphenols formed Al3L2 complexes with conditional stability constants (β) ∼ 1 × 10(23) at pH 6 and AlL complexes with β ∼ 1 × 10(5) at pH 4. Methyl gallate formed AlL complexes with β = 1 × 10(6) at pH 6 but did not complex aluminum at pH 4. At intermediate metal-to-polyphenol ratios, high molecular weight polyphenols formed insoluble Al complexes but methyl gallate complexes were soluble. The high molecular weight polyphenols have high affinities and solubility features that are favorable for a role in aluminum detoxification in the environment. PMID:27022835

  17. Evidence for participation of aluminum in neurofibrillary tangle formation and growth in Alzheimer's disease.

    PubMed

    Walton, J R

    2010-01-01

    This study examines hippocampal CA1 cells from brains of aged humans, with and without Alzheimer's disease, for hyperphosphorylated tau and aluminum during early neurofibrillary tangle (NFT) formation and growth. A very small proportion of hippocampal pyramidal cells contain cytoplasmic pools within their soma that either appear homogeneous or contain short filaments (i.e., early NFTs). The cytoplasmic pools are aggregates of an aluminum/hyperphosphorylated tau complex similar to that found in mature NFTs. The photographic evidence presented combines with existing evidence to support a role for aluminum in the formation and growth of NFTs in neurons of humans with Alzheimer's disease.

  18. Polyphenol-aluminum complex formation: Implications for aluminum tolerance in plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Natural polyphenols may play an important role in aluminum detoxification in some plants. We examined the interaction between Al3+ and the purified high molecular weight polyphenols pentagalloyl glucose (940 Da) and oenothein B (1568 Da), and the related compound methyl gallate (184 Da) at pH 4 and ...

  19. Aluminum-activated citrate and malate transporters from the MATE and ALMT families function independently to confer Arabidopsis aluminum tolerance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aluminum (Al) activated root malate and citrate exudation plays an important role in Al tolerance in many plant species. Here, we report on the identification and characterization of AtMATE, a homolog of the recently discovered sorghum and barley Al tolerance genes, here shown to encode an Al-activ...

  20. Aluminum-activated citrate and malate transporters from the MATE and ALMT families function independently to confer Arabidopsis aluminum tolerance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aluminum (Al) activated root malate and citrate exudation play an important role in Al tolerance in many plant species. AtALMT1, an Al-activated malate transporter, is a major contributor to Arabidopsis Al tolerance. Here, we demonstrate that a second, unrelated gene, AtMATE, encodes an Arabidopsi...

  1. High-aluminum-affinity silica is a nanoparticle that seeds secondary aluminosilicate formation.

    PubMed

    Jugdaohsingh, Ravin; Brown, Andy; Dietzel, Martin; Powell, Jonathan J

    2013-01-01

    Despite the importance and abundance of aluminosilicates throughout our natural surroundings, their formation at neutral pH is, surprisingly, a matter of considerable debate. From our experiments in dilute aluminum and silica containing solutions (pH ~ 7) we previously identified a silica polymer with an extraordinarily high affinity for aluminium ions (high-aluminum-affinity silica polymer, HSP). Here, further characterization shows that HSP is a colloid of approximately 2.4 nm in diameter with a mean specific surface area of about 1,000 m(2) g(-1) and it competes effectively with transferrin for Al(III) binding. Aluminum binding to HSP strongly inhibited its decomposition whilst the reaction rate constant for the formation of the β-silicomolybdic acid complex indicated a diameter between 3.6 and 4.1 nm for these aluminum-containing nanoparticles. Similarly, high resolution microscopic analysis of the air dried aluminum-containing silica colloid solution revealed 3.9 ± 1.3 nm sized crystalline Al-rich silica nanoparticles (ASP) with an estimated Al:Si ratio of between 2 and 3 which is close to the range of secondary aluminosilicates such as imogolite. Thus the high-aluminum-affinity silica polymer is a nanoparticle that seeds early aluminosilicate formation through highly competitive binding of Al(III) ions. In niche environments, especially in vivo, this may serve as an alternative mechanism to polyhydroxy Al(III) species binding monomeric silica to form early phase, non-toxic aluminosilicates.

  2. Evidence of involvement of aluminum in causation of defective formation of eggshells and of impaired breeding in wild passerine birds

    SciTech Connect

    Nyholm, N.E.I.

    1981-12-01

    Aluminum was found in the bone marrow tissue of humeri of wild pied flycatchers (Ficedula hypoleuca), specifically in birds with impaired breeding. Production of only small cluthes, defective eggshell formation, and intrauterine bleeding were characteristic impairments shown by the aluminum-contaminated birds. These impairments agree with the symptoms of aluminum intoxication of mammals (including man) reported in the literature. A possible route of transport of aluminum to the birds is presented, in which acid precipitation is the proximate link.

  3. Observation of low aluminum corrosion rates during biofilm formation

    NASA Astrophysics Data System (ADS)

    Leitz, Markus; Franke, Hilmar

    2002-03-01

    An optical technique based on the surface plasmon resonance of thin was used to study the influence of aqueous organic subtances on thin aluminum films. In a quasi continous flow experiment over several days it was found that the aluminium was dissolved and the thickness decrease could be monitored very accurately. In a series of experiments with different organic components the corrosion could be attributed to the nutrient Alginate promomoting medium and the extracellular polymeric substances produced by the bacteria pseudomonas aeruginosa. In comparison with inorganic substances the same behaviour could not be observed. Regardless of the particular chemical reactions involved this method seems to be suitable to monitor low aluminium corrosion rates in the order of nm/h quite precisely.

  4. Formation of Nanoporous Anodic Alumina by Anodization of Aluminum Films on Glass Substrates.

    PubMed

    Lebyedyeva, Tetyana; Kryvyi, Serhii; Lytvyn, Petro; Skoryk, Mykola; Shpylovyy, Pavlo

    2016-12-01

    Our research was aimed at the study of aluminum films and porous anodic alumina (PAA) films in thin-film РАА/Al structures for optical sensors, based on metal-clad waveguides (MCWG). The results of the scanning electron microscopy (SEM) and atomic force microscopy (AFM) studies of the structure of Al films, deposited by DC magnetron sputtering, and of PAA films, formed on them, are presented in this work.The study showed that the structure of the Al films is defined by the deposition rate of aluminum and the thickness of the film. We saw that under anodization in 0.3 M aqueous oxalic acid solution at a voltage of 40 V, the PAA film with a disordered array of pores was formed on aluminum films 200-600 nm thick, which were deposited on glass substrates with an ultra-thin adhesive Nb layer. The research revealed the formation of two differently sized types of pores. The first type of pores is formed on the grain boundaries of aluminum film, and the pores are directed perpendicularly to the surface of aluminum. The second type of pores is formed directly on the grains of aluminum. They are directed perpendicularly to the grain plains. There is a clear tendency to self-ordering in this type of pores. PMID:27083584

  5. The entropy and Gibbs free energy of formation of the aluminum ion

    USGS Publications Warehouse

    Hemingway, B.S.; Robie, R.A.

    1977-01-01

    A reevaluation of the entropy and Gibbs free energy of formation of Al3+(aq) yields -308 ?? 15 J/K??mol and 489.4 ?? 1.4kj/mol for S0298 and ??G0f{hook},298 respectively. The standard electrode potential for aluminum is 1.691 ?? 0.005 volts. ?? 1977.

  6. Enthalpies of complex formation of boron and aluminum bromides with organic bases of high donor power

    SciTech Connect

    Grigor-ev, A.A.; Kondrat'ev, Y.V.; Suvorov, A.V.

    1986-11-20

    By the calorimetric method enthalpies of complex formation were determined for boron and aluminum bromides with piperidine and hexamethylphosphoric triamide in benzene solutions and for boron bromide with pyridine in dichloroethane, and also enthalpies of solution were determined for BBr/sub 3/ and the adducts AlBr/sub 3/ x PPy and BBr/sub 2/ x Py in benzene and pyridine.

  7. High-Aluminum-Affinity Silica Is a Nanoparticle That Seeds Secondary Aluminosilicate Formation

    PubMed Central

    Jugdaohsingh, Ravin; Brown, Andy; Dietzel, Martin; Powell, Jonathan J.

    2013-01-01

    Despite the importance and abundance of aluminosilicates throughout our natural surroundings, their formation at neutral pH is, surprisingly, a matter of considerable debate. From our experiments in dilute aluminum and silica containing solutions (pH ~ 7) we previously identified a silica polymer with an extraordinarily high affinity for aluminium ions (high-aluminum-affinity silica polymer, HSP). Here, further characterization shows that HSP is a colloid of approximately 2.4 nm in diameter with a mean specific surface area of about 1,000 m2 g-1 and it competes effectively with transferrin for Al(III) binding. Aluminum binding to HSP strongly inhibited its decomposition whilst the reaction rate constant for the formation of the β-silicomolybdic acid complex indicated a diameter between 3.6 and 4.1 nm for these aluminum-containing nanoparticles. Similarly, high resolution microscopic analysis of the air dried aluminum-containing silica colloid solution revealed 3.9 ± 1.3 nm sized crystalline Al-rich silica nanoparticles (ASP) with an estimated Al:Si ratio of between 2 and 3 which is close to the range of secondary aluminosilicates such as imogolite. Thus the high-aluminum-affinity silica polymer is a nanoparticle that seeds early aluminosilicate formation through highly competitive binding of Al(III) ions. In niche environments, especially in vivo, this may serve as an alternative mechanism to polyhydroxy Al(III) species binding monomeric silica to form early phase, non-toxic aluminosilicates. PMID:24349573

  8. Formation of hydrotalcite in mixtures of aluminum hydroxycarbonate and magnesium hydroxide gels.

    PubMed

    Vanderlaan, R K; White, J L; Hem, S L

    1982-07-01

    IR and X-ray analysis demonstrate that hydrotalcite forms during the aging of aluminum hydroxycarbonate gel and magnesium hydroxide gel mixtures. The formation of hydrotalcite produces a change in the pH-stat titrigram and a sharp increase in the pH of the mixture. Hydrotalcite was noted earlier in mixtures having a high molar ratio of magnesium to aluminum, a high total gel concentration, a high initial pH, or in mixtures stored at elevated temperatures. The addition of sorbitol to the mixtures substantially delayed the appearance of hydrotalcite. Nonacid-reactive hydrotalcite formed when mixtures of chloride-containing aluminum hydroxide gel and magnesium hydroxide gel were aged. PMID:7120062

  9. Suppression of phospholipase D,gammas confers increased aluminum resistance in Arabidopsis thaliana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aluminum (Al) toxicity is the major stress in acidic soil that comprises about 50% of the world’s arable land. The complex molecular mechanisms of Al toxicity have yet to be fully determined. As a barrier to Al entrance and attack, plant cell membranes play essential roles in Al toxicity, as lipid c...

  10. The formation mechanism of aluminum oxide tunnel barriers.

    SciTech Connect

    Cerezo, A.; Petford-Long, A. K.; Larson, D. J.; Pinitsoontorn, S.; Singleton, E. W.; Materials Science Division; Univ. Oxford; Seagate Tech.

    2006-01-01

    The functional properties of magnetic tunnel junctions are critically dependant on the nanoscale morphology of the insulating barrier (usually only a few atomic layers thick) that separates the two ferromagnetic layers. Three-dimensional atom probe analysis has been used to study the chemistry of a magnetic tunnel junction structure comprising an aluminium oxide barrier formed by in situ oxidation, both in the under-oxidized and fully oxidized states and before and after annealing. Low oxidation times result in discrete oxide islands. Further oxidation leads to a more continuous, but still non-stoichiometric, barrier with evidence that oxidation proceeds along the top of grain boundaries in the underlying CoFe layer. Post-deposition annealing leads to an increase in the barrier area, but only in the case of the fully oxidized and annealed structure is a continuous planar layer formed, which is close to the stoichiometric Al:O ratio of 2:3. These results are surprising, in that the planar layers are usually considered unstable with respect to breaking up into separate islands. Analysis of the various driving forces suggests that the formation of a continuous layer requires a combination of factors, including the strain energy resulting from the expansion of the oxide during internal oxidation on annealing.

  11. Modeling of microporosity formation during solidification of aluminum alloys

    NASA Astrophysics Data System (ADS)

    Wang, T.; An, D.; Zhang, Q.; Dai, T.; Zhu, M.

    2015-06-01

    A two-dimensional (2D) multi-phase cellular automaton (MCA) model is adopted to simulate the dendrite and microporosity formation during solidification of aluminium alloys. The model involves three phases of liquid, gas, and solid. The effect of liquid-solid phase transformation on the nucleation and growth of porosity, the redistribution and diffusion of solute and hydrogen, and the effects of surface tension and environmental pressure are taken into account. The growth of both dendrite and porosity is simulated using a CA approach. The diffusion of solute and hydrogen is calculated using the finite difference (FD) method. The simulations can reveal the interactive and competitive growth of dendrites and micropores, and the microsegregationof solute and hydrogen. The porosity nuclei with large size are able to grow preferentially, while the growth of the small porosity nuclei is inhibited. Gas pores grow spherically when it is enveloped by liquid. After touching with dendrites, the shapes of pores become irregular. An increased initial hydrogen concentration reduces the incubation time of porosity nucleation, but increases the final percentage of porosity and the average porosity size at the eutectic temperature. With cooling rate decreasing, the competitive growth between gas pores becomes more evident, leading to non-uniform porosity sizes, and more irregular morphology of the porosities with larger size. The simulation results are compared reasonably well with the experimental data reported in literature.

  12. Electrochemical Deposition and Formation Mechanism of Single-Crystalline Cu2O Octahedra on Aluminum

    PubMed Central

    Du, Q. T.; Tan, J. S.; Wang, Q. T.; Li, C. Y.; Liu, X. H.; Cai, R. S.; Ding, Y. H.; Wang, Y. Q.

    2012-01-01

    A simple electrochemical deposition was developed to synthesize the cuprous oxide (Cu2O) octahedra on aluminum foils. The average edge length of the octahedra is about 300 nm. The chemical composition of the octahedra was determined using energy dispersive X-ray spectroscopy and electron energy-loss spectroscopy. The microstructure of the octahedra was investigated using transmission electron microscopy. The formation mechanism of the octahedra is proposed. PMID:22779036

  13. Formation and evolution of tweed structures on high-purity aluminum polycrystalline foils under cyclic tension

    NASA Astrophysics Data System (ADS)

    Kuznetsov, P. V.; Vlasov, I. V.; Sklyarova, E. A.; Smekalina, T. V.

    2015-10-01

    Peculiarities of formation and evolution of tweed structures on the surface of high-purity aluminum polycrystalline foils under cyclic tension were studied using an atom force microscope and a white light interferometer. Tweed structures of micron and submicron sizes were found on the foils at different number of cycles. In the range of 42,000 < N < 95,000 cycles destruction of tweed patterns is observed, which leads to their disappearance from the surface of the foils. Formation of tweed structures of various scales is discussed in terms of the Grinfeld instability.

  14. Formation and evolution of tweed structures on high-purity aluminum polycrystalline foils under cyclic tension

    SciTech Connect

    Kuznetsov, P. V.; Vlasov, I. V.; Sklyarova, E. A.; Smekalina, T. V.

    2015-10-27

    Peculiarities of formation and evolution of tweed structures on the surface of high-purity aluminum polycrystalline foils under cyclic tension were studied using an atom force microscope and a white light interferometer. Tweed structures of micron and submicron sizes were found on the foils at different number of cycles. In the range of 42,000 < N < 95,000 cycles destruction of tweed patterns is observed, which leads to their disappearance from the surface of the foils. Formation of tweed structures of various scales is discussed in terms of the Grinfeld instability.

  15. Formation and emission of brominated dioxins and furans during secondary aluminum smelting processes.

    PubMed

    Wang, Mei; Liu, Guorui; Jiang, Xiaoxu; Li, Sumei; Liu, Wenbin; Zheng, Minghui

    2016-03-01

    Secondary aluminum smelting (SAl) processes have previously been found to be important sources of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs). It is crucial that the key factors that influence the formation and emission of PBDD/Fs are identified to allow techniques for decreasing PBDD/F emissions during SAl processes to be developed. In this study, stack gas samples were collected from four typical secondary aluminum smelters that used different raw materials, and the samples were analyzed to allow differences between PBDD/F emissions from different SAl plants to be assessed. The composition of the raw materials was found to be one of the key factors influencing the amounts of PBDD/Fs emitted. The PBDD/F emission factors (per tonne of aluminum produced) for the plants using 100% (Plant1), 80% (Plant2), and 50% (Plant3) dirty aluminum scrap in the raw material feed were 180, 86, and 14 μg t(-1), respectively. The amounts of PBDD/Fs emitted at different stages of the smelting process (feeding-fusion, refining, and casting) were compared, and the feeding-fusion stage was found to be the main stage in which PBDD/Fs were formed and emitted. Effective aluminum scrap pretreatments could significantly decrease PBDD/F emissions. Much higher polybrominated dibenzofuran concentrations than polybrominated dibenzo-p-dioxin concentrations were found throughout the SAl process. The more-brominated congeners (including octabromodibenzo-p-dioxin, octabromodibenzofuran, heptabromodibenzo-p-dioxins, and heptabromodibenzofurans) were the dominant contributors to the total PBDD/F concentrations. The results could help in the development of techniques and strategies for controlling PBDD/F emissions during metallurgical processes.

  16. Formation regularities of AlOOH hollow spheres during aluminum nanopowder water oxidation

    NASA Astrophysics Data System (ADS)

    Lozhkomoev, Aleksandr S.; Glazkova, Elena A.; Svarovskaya, Natalia V.; Bakina, Olga V.; Kazantsev, Sergey O.; Lerner, Marat I.

    2015-10-01

    There described a novel environmentally friendly synthesis route of micro/nanostructured hollow spheres of AlOOH by oxidation of Al nanopowder in pure water under mild processing conditions. The reaction kinetics of the aluminum nanopowder interaction with water was studied using the method of continuous recording of suspension pH and temperature. There observed the change in Al3+ concentration in the reaction medium and the rate of hydrogen release as well as TEM investigations of the intermediate reaction products at different stages of the process were performed. It is shown that AlOOH hollow spheres are formed through the aluminum core dissolution, Al3+ ion diffusion through the surface oxide film and AlOOH nanosheets formation on the surface of the precursor oxide film.

  17. Aluminum-humic colloid formation during pre-coagulation for membrane water treatment: mechanisms and impacts.

    PubMed

    Wang, Zhengyang; Teychene, Benoît; Chalew, Talia E Abbott; Ajmani, Gaurav S; Zhou, Tao; Huang, Haiou; Wu, Xiaohui

    2014-09-15

    Precoagulation has been widely used by low pressure membrane filtration (LPMF) plants to reduce membrane fouling and increase natural organic matter (NOM) removal. Formation of aluminum and aluminum-NOM moieties plays a fundamental role in this important water treatment process. This study comprehensively investigated the mechanisms of aluminum-NOM species formation during precoagulation and their impacts on LPMF performance. The results show that, at low alum doses, e.g. 0.5 mg and 1.0 mg Al L(-1), humic substances (HS) and Al species (amorphous Al(OH)3, or Al(OH)3(am)) reacted to form small Al(OH)3(am)-HS colloids. Increases in alum dose resulted in sequential transitions of the Al-HS moieties to larger particles and, eventually, precipitates. Compared to waters containing only naturally occurring organic colloids (OC) or HS, the coexistence of OC and HS facilitated the formation of Al-HS precipitates, thereby increasing the removal of HS by 7-15%, but the removal of OC was decreased by 3-20%. Interestingly, these transitions in Al-HS moieties did not affect membrane fouling. Both short-term and long-term filtration results demonstrate that OC, rather than the Al(OH)3(am)-HS colloids, primarily caused membrane fouling. These findings highlight the dynamics of particulate Al-NOM formation during precoagulation and its relationship with membrane fouling, which can be utilized to optimize the operation of integrated precoagulation-LPMF systems on full-scale installations.

  18. Formation of calcium in the products of iron oxide-aluminum thermite combustion in air

    NASA Astrophysics Data System (ADS)

    Gromov, A. A.; Gromov, A. M.; Popenko, E. M.; Sergienko, A. V.; Sabinskaya, O. G.; Raab, B.; Teipel, U.

    2016-10-01

    The composition of condensed products resulting from the combustion of thermite mixtures (Al + Fe2O3) in air is studied by precise methods. It is shown that during combustion, calcium is formed and stabilized in amounts of maximal 0.55 wt %, while is missing from reactants of 99.7 wt % purity. To explain this, it is hypothesized that a low-energy nuclear reaction takes place alongside the reactions of aluminum oxidation and nitridation, resulting in the formation of calcium (Kervran-Bolotov reaction).

  19. Experimental study of void formation during aluminum solidification in reduced gravity. Ph.D. Thesis - Toledo Univ.

    NASA Technical Reports Server (NTRS)

    Chiaramonte, Francis Paul, III

    1993-01-01

    Void formation due to volumetric shrinkage and liquid/vapor reorientation during aluminum solidification was observed in real time by using a radiographic viewing system in normal and reduced gravity. An end-chill directional solidification furnace with water quench was designed and constructed to solidify aluminum samples during the approximately 16 sec of reduced gravity (+/-0.02g) achieved by flying an aircraft through a parabolic trajectory. In the first series of tests the aluminum was contained in a vacuum sealed, pyrolytic boron nitride crucible. An ullage space was present during each test. Void formation was recorded for two cases: a nonwetting system, and a wetting system where wetting occurred between the aluminum and the crucible lid. The void formation in the nonwetting case was similar in normal and reduced gravity, with a single vapor cavity forming at the top of the crucible. In the wetting case during reduced gravity surface tension caused two voids to form in the top corners of the crucible, but during normal gravity only one large void formed across the top. In the second series of tests the aluminum was contained in a pyrolytic boron nitride crucible that was placed in a stainless steel container and sealed in an environment of argon plus 4 percent hydrogen. An ullage space was present during each test. Void formation was recorded for two cases: a nonwetting system, and a wetting system where wetting occurred between the aluminum and one side wall and the lid. The void for nation in the nonwetting case was similar in normal and reduced gravity, with a single vapor cavity forming at the top of the crucible, although the meniscus became more convex in reduced gravity. In the wetting case the aluminum did not climb up the corners in 1g, and one large symmetric void resulted at the top when the aluminum had solidified. In the wetting case during reduced gravity the molten aluminum was drawn up the wetted wall and partially across the lid by a

  20. Sister Mary Emil Penet, I.H.M.: Founder of the Sister Formation Conference

    ERIC Educational Resources Information Center

    Glisky, Joan

    2006-01-01

    Mary Emil Penet, I.H.M., (1916-2001) used her talents and charisma to shape the first national organization of American women religious, the Sister Formation Conference (SFC; 1954-1964), facilitating the integrated intellectual, spiritual, psychological, and professional development of vowed women religious. In the decade preceding Vatican II, her…

  1. The formation of an ordered microporous aluminum-based material mediated by phthalic acid.

    PubMed

    Zhang, Wei; Cai, Jian-Hua; Huang, Pei-Pei; Hu, Lin-Lin; Cao, An-Min; Wan, Li-Jun

    2016-06-28

    By using phthalic acid as a soft template, we showed that it was possible to prepare a microporous aluminum-based material when the precipitation of Al(3+) was properly controlled. We also identified that this microporous aluminum-based material could be promising for the removal of fluoride ions in water treatment. PMID:27263661

  2. Structure and kinetics of formation of interphase layers of synthetic fatty acid aluminum soap at the water/oil interface

    SciTech Connect

    Chalykh, A.E.; Matveev, V.V.; Mityuk, D.Y.; Shal't, S.Y.; Tarasevich, B.N.

    1986-02-01

    The authors investigate the kinetics of formation of interphase layers (IL) at the interface between the phases: a 0.15% solution of aluminum soap of synthetic fatty acids (SFA) (fraction C/sub 17/-C/sub 21/) in n-decane/distilled water. The structure and the morphological properties of IL were investigated by transmission electron spectroscopy. The electron micrographs of the interphase layer of the soap at different stages of its formation show that the formation of a new phase starts with the appearance of small dispersed particles with spherical and fibrillar shapes. The results obtained supplement the authors' concepts about the mechanism of spontaneous microemulsification.

  3. On Vertical Drag Defects Formation During Direct Chill (DC) Casting of Aluminum Billets

    NASA Astrophysics Data System (ADS)

    Carlberg, Torbjörn; Jarfors, Anders E. W.

    2013-12-01

    During air-slip direct chill casting of aluminum billets, one of the major defects occurring includes traces along the billet called vertical drags (VDs). If the VDs are too deep or too many, then they cause scraping of the billets. As in the subsequent extrusion process, the surface quality is known to impair both the productivity and quality of the profiles. In cast-house practice, many theories circulate about the causes of VD defects and how to avoid them, but in the literature, no thorough treatments have been made to explain this phenomenon. In the current study, the outer appearance, structure around, and compositions at the defects are analyzed. A theory for the formation of the defects, their cause, and how their appearance is coupled to different alloy types is presented. The segregation in the vicinity of the defects is discussed based on deformation of semisolid materials and coupled to Reynolds dilatancy in granular materials. The theory can explain differences between 6063 and 6005 alloys.

  4. Prediction of Hot Tear Formation in Vertical DC Casting of Aluminum Billets Using a Granular Approach

    NASA Astrophysics Data System (ADS)

    Sistaninia, M.; Drezet, J.-M.; Phillion, A. B.; Rappaz, M.

    2013-09-01

    A coupled hydromechanical granular model aimed at predicting hot tear formation and stress-strain behavior in metallic alloys during solidification is applied to the semicontinuous direct chill casting of aluminum alloy round billets. This granular model consists of four separate three-dimensional (3D) modules: (I) a solidification module that is used for generating the solid-liquid geometry at a given solid fraction, (II) a fluid flow module that is used to calculate the solidification shrinkage and deformation-induced pressure drop within the intergranular liquid, (III) a semisolid deformation module that is based on a combined finite element/discrete element method and simulates the rheological behavior of the granular structure, and (IV) a failure module that simulates crack initiation and propagation. To investigate hot tearing, the granular model has been applied to a representative volume within the direct chill cast billet that is located at the bottom of the liquid sump, and it reveals that semisolid deformations imposed on the mushy zone open the liquid channels due to localization of the deformation at grains boundaries. At a low casting speed, only individual pores are able to form in the widest channels because liquid feeding remains efficient. However, as the casting speed increases, the flow of liquid required to compensate for solidification shrinkage also increases and as a result the pores propagate and coalesce to form a centerline crack.

  5. A model for the formation of fatigue striations and its relationship with small fatigue crack growth in an aluminum alloy

    SciTech Connect

    Shyam, Amit; Lara-Curzio, Edgar

    2010-01-01

    The fatigue crack growth process involves damage accumulation and crack extension. The two sub-processes that lead to fatigue crack extension were quantified separately in a recent model for small fatigue crack growth applicable to engineering alloys. Here, we report the results of an experimental investigation to assess the assumptions of that model. The fatigue striation formation in an aluminum alloy is modeled and it is verified that the number of cycles required for striation formation is related to the cyclic crack tip opening displacement and that the striation spacing is related to the monotonic crack tip displacement. It is demonstrated that extensive cyclic crack tip plasticity in the aluminum alloy causes a reduction in the magnitude of the slope of the fatigue crack propagation curves. The implications of these results on the fatigue crack propagation lifetime calculations are identified.

  6. The utility of the matrix format for surgical morbidity and mortality conference.

    PubMed

    Bhalla, Varun K; Boone, Luke; Lewis, Frank; Gucwa, Angela L; Kruse, E James

    2015-05-01

    With the limitations posed by increasing work hour restrictions, surgical residency programs are focusing more on maximizing the educational benefit of their conferences. The Morbidity and Mortality (M&M) conference serves as a forum to discuss adverse events and patient care improvement using evidence-based medicine. The matrix format (MF) is an enhancement to the traditional format (TF), focusing on the case selection process and a postconference newsletter reiterating the relevant literature review and discussion points. Our institution adopted the MF to evaluate both its short- and long-term educational values. Surveys were distributed to residents and faculty within the Department of General Surgery to assess their interest and satisfaction, perception of educational value, and efficiency with the MF compared with the TF. Responses were obtained from 22/22 (100%) residents for the TF and 11/23 (48%) for the MF. Faculty responses were 19/19 (100%) and 9/16 (56%), respectively. Reasons for an overall decreased response with the MF were not investigated further, as participation was strictly voluntary. Our results confirmed an overall approval of the MF by both residents and faculty. Faculty reported an improved efficiency of the conference (P < 0.039), encompassing improved content and presentation quality. Residents reported an improved overall interest and satisfaction with the MF (P < 0.001) as well as an improvement in the educational value (P < 0.007). Residents spent less time preparing presentations and reported learning greater educational benefit to the conference when preparing their own presentations (P < 0.001). In conclusion, the MF resulted in a greater overall satisfaction for residents and attending surgeons with an increased investment by the audience and overall improvement in perceived educational benefit.

  7. Formation and Structure of the Aluminum-Silicon CARBIDE(0001) Interface

    NASA Astrophysics Data System (ADS)

    Sun, Bingxi

    The structure and chemistry of the interface between aluminum and single crystal SiC is of potential interest in both the composite materials and microelectronics industries. In this thesis, the development of this interface has been studied by using a range of surface science techniques. Interfaces were formed by vapor deposition of up to several monolayers of aluminum onto a clean, stoichiometric 6H-SiC(0001) surface in ultrahigh vacuum. The growth mechanism, changes in adlayer morphology, desorption upon annealing and film/substrate interfacial reactions were studied in situ by Auger electron spectroscopy, Auger depth profiling and thermal desorption spectroscopy. Results indicate that the aluminum deposited onto the surface at room temperature is metallic, and that deposition proceeds by the nucleation and growth of three-dimensional islands on the otherwise bare SiC surface, by the Volmer -Weber mechanism. The details of the growth process depend on the deposition rate, with some island coalescence occurring during deposition. Heating the films subsequent to deposition leads first to further island coalescence, followed by desorption of a fraction of the aluminum and reaction of the remaining aluminum with the SiC surface to form a monolayer of Al _4C_3 on the surface. Thermal desorption spectroscopy studies showed first order kinetics at low adlayer coverages, giving way to zero order kinetics at higher coverages. In both regimes, the desorption activation energy was approximately 40 Kcal/mol. This behavior is explained in terms of desorption from an aluminum adlayer on the SiC surface, with the adlayer population being maintained by the detachment of aluminum atoms from the islands at high coverages. The implications from this work are that the as -deposited interface is stable up to 700 K, but that a reaction to produce Al_4C_3 takes place at higher temperatures. This reaction product is stable up to at least 1100 K, well above the melting point of aluminum

  8. Cage Structure Formation of Singly Doped Aluminum Cluster Cations Al n TM + ( TM = Ti, V, Cr)

    NASA Astrophysics Data System (ADS)

    Lang, Sandra M.; Claes, Pieterjan; Neukermans, Sven; Janssens, Ewald

    2011-09-01

    Structural information on free transition metal doped aluminum clusters, Al n TM + ( TM = Ti, V, Cr), was obtained by studying their ability for argon physisorption. Systematic size ( n = 5 - 35) and temperature ( T = 145 - 300 K) dependent investigations reveal that bare Al n + clusters are inert toward argon, while Al n TM + clusters attach one argon atom up to a critical cluster size. This size is interpreted as the geometrical transition from surface-located dopant atoms to endohedrally doped aluminum clusters with the transition metal atom residing in an aluminum cage. The critical size, n crit , is found to be surprisingly large, namely n crit = 16 and n crit = 19 - 21 for TM = V, Cr, and TM = Ti, respectively. Experimental cluster-argon bond dissociation energies have been derived as function of cluster size from equilibrium mass spectra and are in the 0.1-0.3 eV range.

  9. Aluminum-phosphate binder formation in zeolites as probed with X-ray absorption microscopy.

    PubMed

    van der Bij, Hendrik E; Cicmil, Dimitrije; Wang, Jian; Meirer, Florian; de Groot, Frank M F; Weckhuysen, Bert M

    2014-12-24

    In this work, three industrially relevant zeolites with framework topologies of MOR, FAU and FER have been explored on their ability to form an AlPO4 phase by reaction of a phosphate precursor with expelled framework aluminum. A detailed study was performed on zeolite H-mordenite, using in situ STXM and soft X-ray absorption tomography, complemented with (27)Al and (31)P magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy, XRD, FT-IR spectroscopy, and N2 physisorption. Extraframework aluminum was extracted from steam-dealuminated H-mordenite and shown to dominantly consist of amorphous AlO(OH). It was found that phosphoric acid readily reacts with the AlO(OH) phase in dealuminated H-mordenite and forms an extraframework amorphous AlPO4 phase. It was found that while AlPO4 crystallizes outside of the zeolitic channel system forming AlPO4 islands, AlPO4 that remains inside tends to stay more amorphous. In the case of ultrastable zeolite Y the FAU framework collapsed during phosphatation, due to extraction of framework aluminum from the lattice. However, using milder phosphatation conditions an extraframework AlPO4 α-cristobalite/tridymite phase could also be produced within the FAU framework. Finally, in steamed zeolite ferrierite with FER topology the extraframework aluminum species were trapped and therefore not accessible for phosphoric acid; hence, no AlPO4 phase could be formed within the structure. Therefore, the parameters to be taken into account in AlPO4 synthesis are the framework Si/Al ratio, stability of framework aluminum, pore dimensionality and accessibility of extraframework aluminum species.

  10. Aluminum-phosphate binder formation in zeolites as probed with X-ray absorption microscopy.

    PubMed

    van der Bij, Hendrik E; Cicmil, Dimitrije; Wang, Jian; Meirer, Florian; de Groot, Frank M F; Weckhuysen, Bert M

    2014-12-24

    In this work, three industrially relevant zeolites with framework topologies of MOR, FAU and FER have been explored on their ability to form an AlPO4 phase by reaction of a phosphate precursor with expelled framework aluminum. A detailed study was performed on zeolite H-mordenite, using in situ STXM and soft X-ray absorption tomography, complemented with (27)Al and (31)P magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy, XRD, FT-IR spectroscopy, and N2 physisorption. Extraframework aluminum was extracted from steam-dealuminated H-mordenite and shown to dominantly consist of amorphous AlO(OH). It was found that phosphoric acid readily reacts with the AlO(OH) phase in dealuminated H-mordenite and forms an extraframework amorphous AlPO4 phase. It was found that while AlPO4 crystallizes outside of the zeolitic channel system forming AlPO4 islands, AlPO4 that remains inside tends to stay more amorphous. In the case of ultrastable zeolite Y the FAU framework collapsed during phosphatation, due to extraction of framework aluminum from the lattice. However, using milder phosphatation conditions an extraframework AlPO4 α-cristobalite/tridymite phase could also be produced within the FAU framework. Finally, in steamed zeolite ferrierite with FER topology the extraframework aluminum species were trapped and therefore not accessible for phosphoric acid; hence, no AlPO4 phase could be formed within the structure. Therefore, the parameters to be taken into account in AlPO4 synthesis are the framework Si/Al ratio, stability of framework aluminum, pore dimensionality and accessibility of extraframework aluminum species. PMID:25415849

  11. The role of the vacancy complexes of nanocompacted aluminum particles on the formation of structure during heat treatment

    NASA Astrophysics Data System (ADS)

    Gafner, Yu Ya; Baidyshev, V. S.

    2015-04-01

    The boundaries of thermal stability of the initial face-centered cubic (fcc) phase in perfect aluminum clusters with a diameter up to 3 nm have been investigated by the molecular dynamics method using a modified tight binding (TB-SMA) potential. Based on the performed computer analysis, it has been concluded that, in most cases, for aluminum clusters with sizes up to D = 2.5 nm, the most stable configuration is the structure with pentagonal symmetry. With a further increase in the number of atoms, the fcc structure becomes more stable. The influence of the degree of disorder of nanocompacted aluminum particles up to 4 nm in diameter on the formation of a crystal structure during heat treatment has been analyzed. It has been shown that, under the effect of the temperature factor, the clusters undergo a transition from the initial fcc phase to other structural modifications, including those with pentagonal symmetry, even in the case of clusters with fairly large sizes.

  12. Formation of oxide layers on aluminum, niobium, and tantalum in molten alkali metal carbonates

    NASA Astrophysics Data System (ADS)

    Nikitina, E. V.; Kazakovtseva, N. A.

    2013-08-01

    The electrochemical synthesis of niobium, tantalum, and aluminum oxide nanolayers is studied in the melt of lithium, sodium, and potassium carbonates with various additives to a salt phase in an oxidizing atmosphere at a temperature of 773 and 873 K. A scheme is proposed for high-temperature anion local activation of the process.

  13. Effects of Ni(2+) on aluminum hydroxide scale formation and transformation on a simulated drinking water distribution system.

    PubMed

    Wang, Wendong; Song, Shan; Zhang, Xiaoni; Mitchell Spear, J; Wang, Xiaochang; Wang, Wen; Ding, Zhenzhen; Qiao, Zixia

    2014-07-01

    Observations of aluminum containing sediments/scales formed within the distribution pipes have been reported for several decades. In this study, the effect of Ni(2+) on the formation and transformation processes of aluminum hydroxide sediment in a simulated drinking water distribution system were investigated using X-ray diffraction spectrum (XRD), Fourier transform infrared spectrum (FT-IR), scanning electron microscope (SEM), and thermodynamic calculation methods. It was determined that the existence of Ni(2+) had notable effects on the formation of bayerite. In the system without Ni(2+) addition, there was no X-ray diffraction signal observed after 400 d of aging. The presence of Ni(2+), however, even when present in small amounts (Ni/Al=1:100) the formation of bayerite would occur in as little as 3d at pH 8.5. As the molar ratio of Ni/Al increase from 1:100 to 1:10, the amount of bayerite formed on the pipeline increased further; meanwhile, the specific area of the pipe scale decreased from 160 to 122 m(2)g(-1). In the system with Ni/Al molar ratio at 1:3, the diffraction spectrum strength of bayerite became weaker, and disappeared when Ni/Al molar ratios increased above 1:1. At these highs Ni/Al molar ratios, Ni5Al4O11⋅18H2O was determined to be the major component of the pipe scale. Further study indicated that the presence of Ni(2+) promoted the formation of bayerite and Ni5Al4O11⋅18H2O under basic conditions. At lower pH (6.5) however, the existence of Ni(2+) had little effect on the formation of bayerite and Ni5Al4O11⋅18H2O, rather the adsorption of amorphous Al(OH)3 for Ni(2+) promoted the formation of crystal Ni(OH)2.

  14. Influence of the surface pre-treatment of aluminum on the processes of formation of cerium oxides protective films

    NASA Astrophysics Data System (ADS)

    Andreeva, R.; Stoyanova, E.; Tsanev, A.; Stoychev, D.

    2016-03-01

    It is known that there is special interest in the contemporary investigations on conversion treatment of aluminum aimed at promoting its corrosion stability, which is focused on electrolytes on the basis of salts of metals belonging to the group of rare-earth elements. Their application is especially attractive, as it enables a successful substitution of the presently applied highly efficient, but at the same time toxic Cr6+-containing electrolytes. The present paper presents a study on the influence of the preliminary alkaline activation and acidic de-oxidation of the aluminum surface on the processes of immersion formation of protective cerium oxides films on Al 1050. The results obtained show that their deposition from simple electrolytes (containing only salts of Ce3+ ions) on the Al surface, treated only in alkaline solution, occurs at a higher rate, which leads to preparing thicker oxide films having a better protective ability. In the cases when the formation of oxide films is realized in a complex electrolyte (containing salts of Ce3+ and Cu2+ ions), better results are obtained with respect to the morphology and protective action of cerium oxides film on samples that have been consecutively activated in alkaline solution and deoxidized in acidic solution. Electrochemical investigations were carried out in a model corrosion medium (0.1 M NaCl); it was shown that the cerium protective films, deposited by immersion, have a cathodic character with regard to the aluminum support and inhibit the occurrence of the depolarizing corrosion process -- the reaction of oxygen reduction.

  15. Formation of linear polyenes in poly(vinyl alcohol) films catalyzed by phosphotungstic acid, aluminum chloride, and hydrochloric acid

    NASA Astrophysics Data System (ADS)

    Tretinnikov, O. N.; Sushko, N. I.; Malyi, A. B.

    2016-07-01

    Formation of linear polyenes-(CH=CH)n-via acid-catalyzed thermal dehydration of polyvinyl alcohol in 9- to 40-µm-thick films of this polymer containing hydrochloric acid, aluminum chloride, and phosphotungstic acid as dehydration catalysts was studied by electronic absorption spectroscopy. The concentration of long-chain ( n ≥ 8) polyenes in films containing phosphotungstic acid is found to monotonically increase with the duration of thermal treatment of films, although the kinetics of this process is independent of film thickness. In films containing hydrochloric acid and aluminum chloride, the formation rate of polyenes with n ≥ 8 rapidly drops as film thickness decreases and the annealing time increases. As a result, at a film thickness of less than 10-12 µm, long-chain polyenes are not formed at all in these films no matter how long thermal duration is. The reason for this behavior is that hydrochloric acid catalyzing polymer dehydration in these films evaporates from the films during thermal treatment, the evaporation rate inversely depending on film thickness.

  16. Copper stabilization via spinel formation during the sintering of simulated copper-laden sludge with aluminum-rich ceramic precursors.

    PubMed

    Tang, Yuanyuan; Chui, Stephen Sin-Yin; Shih, Kaimin; Zhang, Lingru

    2011-04-15

    The feasibility of incorporating copper-laden sludge into low-cost ceramic products, such as construction ceramics, was investigated by sintering simulated copper-laden sludge with four aluminum-rich ceramic precursors. The results indicated that all of these precursors (γ-Al(2)O(3), corundum, kaolinite, mullite) could crystallochemically stabilize the hazardous copper in the more durable copper aluminate spinel (CuAl(2)O(4)) structure. To simulate the process of copper transformation into a spinel structure, CuO was mixed with the four aluminum-rich precursors, and fired at 650-1150 °C for 3 h. The products were examined using powder X-ray diffraction (XRD) and scanning electron microscopic techniques. The efficiency of copper transformation among crystalline phases was quantitatively determined through Rietveld refinement analysis of the XRD data. The sintering experiment revealed that the optimal sintering temperature for CuAl(2)O(4) formation was around 1000 °C and that the efficiency of copper incorporation into the crystalline CuAl(2)O(4) structure after 3 h of sintering ranged from 40 to 95%, depending on the type of aluminum precursor used. Prolonged leaching tests were carried out by using acetic acid with an initial pH value of 2.9 to leach CuO and CuAl(2)O(4) samples for 22 d. The sample leachability analysis revealed that the CuAl(2)O(4) spinel structure was more superior to stabilize copper, and suggested a promising and reliable technique for incorporating copper-laden sludge or its incineration ash into usable ceramic products. Such results also demonstrated the potential of a waste-to-resource strategy by using waste materials as part of the raw materials with the attainable temperature range used in the production of ceramics.

  17. Xyloglucan Endotransglucosylase-Hydrolase17 Interacts with Xyloglucan Endotransglucosylase-Hydrolase31 to Confer Xyloglucan Endotransglucosylase Action and Affect Aluminum Sensitivity in Arabidopsis1[OPEN

    PubMed Central

    Zhu, Xiao Fang; Wan, Jiang Xue; Sun, Ying; Shi, Yuan Zhi; Braam, Janet; Li, Gui Xin; Zheng, Shao Jian

    2014-01-01

    Previously, we reported that although the Arabidopsis (Arabidopsis thaliana) Xyloglucan Endotransglucosylase-Hydrolase31 (XTH31) has predominately xyloglucan endohydrolase activity in vitro, loss of XTH31 results in remarkably reduced in vivo xyloglucan endotransglucosylase (XET) action and enhanced Al resistance. Here, we report that XTH17, predicted to have XET activity, binds XTH31 in yeast (Saccharomyces cerevisiae) two-hybrid and coimmunoprecipitations assays and that this interaction may be required for XTH17 XET activity in planta. XTH17 and XTH31 may be colocalized in plant cells because tagged XTH17 fusion proteins, like XTH31 fusion proteins, appear to target to the plasma membrane. XTH17 expression, like that of XTH31, was substantially reduced in the presence of aluminum (Al), even at concentrations as low as 10 µm for 24 h or 25 µm for just 30 min. Agrobacterium tumefaciens-mediated transfer DNA insertion mutant of XTH17, xth17, showed low XET action and had moderately shorter roots than the wild type but was more Al resistant than the wild type. Similar to xth31, xth17 had low hemicellulose content and retained less Al in the cell wall. These data suggest a model whereby XTH17 and XTH31 may exist as a dimer at the plasma membrane to confer in vivo XET action, which modulates cell wall Al-binding capacity and thereby affects Al sensitivity in Arabidopsis. PMID:24948835

  18. Characterization of Monolayer Formation on Aluminum-Doped Zinc Oxide Thin Films

    SciTech Connect

    Rhodes,C.; Lappi, S.; Fischer, D.; Sambasivan, S.; Genzer, J.; Franzen, S.

    2008-01-01

    The optical and electronic properties of aluminum-doped zinc oxide (AZO) thin films on a glass substrate are investigated experimentally and theoretically. Optical studies with coupling in the Kretschmann configuration reveal an angle-dependent plasma frequency in the mid-IR for p-polarized radiation, suggestive of the detection of a Drude plasma frequency. These studies are complemented by oxygen depletion density functional theory studies for the calculation of the charge carrier concentration and plasma frequency for bulk AZO. In addition, we report on the optical and physical properties of thin film adlayers of n-hexadecanethiol (HDT) and n-octadecanethiol (ODT) self-assembled monolayers (SAMs) on AZO surfaces using reflectance FTIR spectroscopy, X-ray photoelectron spectroscopy (XPS), contact angle, and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. Our characterization of the SAM deposition onto the AZO thin film reveals a range of possible applications for this conducting metal oxide.

  19. Experimental study to validate a model of hillock{close_quote}s formation in aluminum thin films

    SciTech Connect

    Genin, F.Y.; Siekhaus, W.J.

    1996-04-01

    The growth of holes and hillocks in thin films has been reported extensively and for a multitude of film{endash}substrate systems. A recently developed model [F. Y. G{acute e}nin, J. Appl. Phys. {bold 77}, 5130 (1995)] which analyzes the formation of a ridge at a traveling grain boundary due to stress and capillarity driving forces provides a quantitative description of the growth of the hillocks. In order to test the model, the surface morphology of aluminum thin films deposited on oxidized silicon substrates and annealed at 450{degree}C in argon is investigated; the profiles of thermal hillocks are measured by atomic force microscopy. The comparison shows excellent agreement between modeled and experimental profiles. {copyright}{ital 1996 American Institute of Physics.}

  20. The formation of iron aluminides on aluminum surface by using a Q-switched Nd:YAG laser

    SciTech Connect

    Bidin, Noriah; Al-Wafi, Yusef A.

    2014-03-05

    The formation and growth of Fe based aluminum diffusion layers at the Fe-Al interface have been investigated to improve the surface hardness. The diffusion of Fe into Al has been accomplished by focusing a Q-switched Nd:YAG laser on the modified surface. The variety of the layer depth is achieved based on the type of heating and quenching media. Microstructural characterization and mechanical properties of the modified surface were carried out via gas discharge spectrometer GDS, X-Ray diffraction (XRD), Scanning electron microscope (SEM), and Vickers Hardness tester. The results indicate that hardness at the interface of Fe-Al layer is increased. The optimum hardness achieved as 93 HV at corresponding critical energy density of 438 Jcm{sup −2}.

  1. Formation of layered Fe(II)-Al(III)-hydroxides during reaction of Fe(II) with aluminum oxide.

    PubMed

    Elzinga, Evert J

    2012-05-01

    The reactivity of aqueous Fe(II) with aluminum oxide in anoxic solutions was investigated with batch kinetic experiments combined with Fe K edge X-ray absorption spectroscopy measurements to characterize Fe(II) sorption products. Formation of Fe(II)-Al(III)-layered double hydroxides with an octahedral sheet structure similar to nikischerite (NaFe(II)(6) Al(3)(SO(4))(2)(OH)(18) (H(2)O)(12)) was observed within a few hours during sorption at pH 7.5 and aqueous Fe(II) concentrations of 1-3 mM. These Fe(II) phases are composed of brucite-like Fe(II)(OH)(2) sheets with partial substitution of Al(III) for Fe(II), charge balanced by anions coordinated along the basal planes. Their fast rate of formation suggests that these previously unrecognized Fe(II) phases, which are structurally and compositionally similar to green rust, may be an important sink of Fe(II) in suboxic and anoxic geochemical environments, and impact the fate of structurally compatible trace metals, such as Co(II), Ni(II), and Zn(II), as well as redox-reactive species including Cr(VI) and U(VI). Further studies are required to assess the thermodynamics, formation kinetics, and stability of these Fe(II) minerals under field conditions. PMID:22409244

  2. Formation of stacking faults and the screw dislocation-driven growth: a case study of aluminum nitride nanowires.

    PubMed

    Meng, Fei; Estruga, Marc; Forticaux, Audrey; Morin, Stephen A; Wu, Qiang; Hu, Zheng; Jin, Song

    2013-12-23

    Stacking faults are an important class of crystal defects commonly observed in nanostructures of close packed crystal structures. They can bridge the transition between hexagonal wurtzite (WZ) and cubic zinc blende (ZB) phases, with the most known example represented by the "nanowire (NW) twinning superlattice". Understanding the formation mechanisms of stacking faults is crucial to better control them and thus enhance the capability of tailoring physical properties of nanomaterials through defect engineering. Here we provide a different perspective to the formation of stacking faults associated with the screw dislocation-driven growth mechanism of nanomaterials. With the use of NWs of WZ aluminum nitride (AlN) grown by a high-temperature nitridation method as the model system, dislocation-driven growth was first confirmed by transmission electron microscopy (TEM). Meanwhile numerous stacking faults and associated partial dislocations were also observed and identified to be the Type I stacking faults and the Frank partial dislocations, respectively, using high-resolution TEM. In contrast, AlN NWs obtained by rapid quenching after growth displayed no stacking faults or partial dislocations; instead many of them had voids that were associated with the dislocation-driven growth. On the basis of these observations, we suggest a formation mechanism of stacking faults that originate from dislocation voids during the cooling process in the syntheses. Similar stacking fault features were also observed in other NWs with WZ structure, such as cadmium sulfide (CdS) and zinc oxide (ZnO).

  3. Aluminum in magnesium silicate perovskite: Formation, structure, and energetics of magnesium-rich defect solid solutions

    NASA Astrophysics Data System (ADS)

    Navrotsky, Alexandra; Schoenitz, Mirko; Kojitani, Hiroshi; Xu, Hongwu; Zhang, Jianzhong; Weidner, Donald J.; Jeanloz, Raymond

    2003-07-01

    MgSiO3-rich perovskite is expected to dominate Earth's lower mantle (pressures >25 GPa) with iron and aluminum as significant substituents. The incorporation of trivalent ions, M3+, may occur by two competing mechanisms: MgA + SiB = MA + MB and SiB = AlB + 0.5 (vacancy)O. Phase synthesis studies show that both substitutions do occur and the nonstoichiometric or defect substitution is prevalent along the MgSiO3-MgAlO2.5 join. Lattice parameters associated with the first substitution (stoichiometric) show more rapid increases with increasing Al content than those for the second substitution (nonstoichiometric), consistent with the differences in size of substituting ions. Oxide melt solution calorimetry has been used to compare the energetics of both substitutions. The stoichiometric substitution, represented by the reaction 0.95 MgSiO3 (perovskite) + 0.05 Al2O3 (corundum) = Mg0.95Al0.10Si0.95O3 (perovskite), has an enthalpy of -0.8 ± 2.2 kJ/mol. The nonstoichiometric reaction, 0.90 MgSiO3 (perovskite) + 0.10 MgO (rocksalt) + 0.05 Al2O3 (corundum) = MgSi0.9Al0.1O2.95 (perovskite) has a small positive enthalpy of 8.5 ± 4.6 kJ/mol. Configurational T ΔS terms play a role in both substitutions. The defect substitution is not prohibitive in enthalpy, entropy, or volume, is favored in perovskite coexisting with magnesiowüstite and may significantly affect the elasticity, rheology, and water retention of silicate perovskite in Earth.

  4. Effect of dislocation structure evolution on low-angle grain boundary formation in 7050 aluminum alloy during aging

    NASA Astrophysics Data System (ADS)

    Gu, Wei; Li, Jing-yuan; Wang, Yi-de

    2015-07-01

    The effect of dislocation structure evolution on low-angle grain boundary formation in 7050 aluminum alloy during aging was studied by using optical microscopy, transmission electron microscopy, and electron backscatter diffraction analysis of misorientation angle distribution, cumulative misorientation and geometrically necessary dislocation (GND) density. Experimental results indicate that coarse spindle-shaped grains with the dimension of 200 µm × 80 µm separate into fine equiaxed grains of 20 µm in size as a result of newborn low-angle grain boundaries formed during the aging process. More specifically, the dislocation arrays, which are rearranged and formed due to scattered dislocations during earlier quenching, transform into low-angle grain boundaries with aging time. The relative frequency of 3°-5° low-angle grain boundaries increases to over 30%. The GND density, which describes low-angle grain boundaries with the misorientation angle under 3°, tends to decrease during initial aging. The inhomogeneous distribution of GNDs is affected by grain orientation. A decrease in GND density mainly occurs from 1.83 × 1013 to 4.40 × 1011 m-2 in grains with <111> fiber texture. This is consistent with a decrease of unit cumulative misorientation. Precipitation on grain boundaries and the formation of a precipitation free zone (PFZ) are facilitated due to the eroding activity of the Graff etchant. Consequently, low-angle grain boundaries could be readily viewed by optical microscopy due to an increase in their electric potential difference.

  5. Fundamental study of the austenite formation and decomposition in low-silicon, aluminum added TRIP steels

    NASA Astrophysics Data System (ADS)

    Garcia-Gonzalez, Jose Enrique

    2005-11-01

    TRIP (Transformation Induced Plasticity) steels are under development for automotive applications that require high strength and excellent formability. Conventional TRIP steels consist of a multiphase microstructure comprised of a ferrite matrix with a dispersion of bainite and metastable retained austenite. The high ductility exhibited by these steels results from the transformation of the metastable retained austenite to martensite during straining. In conventional TRIP steel processing, the multiphase microstructure is obtained by controlled cooling from the alpha + gamma region to an isothermal holding temperature. During this holding, bainite forms and carbon is rejected out into the austenite, which lowers the Ms temperature and stabilizes the austenite to room temperature. In this research project, a fundamental study of a low-Si, Mo-Nb added cold rolled TRIP steel with and without Al additions was conducted. In this study, the recrystallization of cold-rolled ferrite, the formation of austenite during intercritical annealing and the characteristics of the decomposition of the intercritically annealed austenite by controlled cooling rates were systematically assessed. Of special interest were: (i) the effect of the initial hot band microstructure, (ii) the formation of epitaxial ferrite during cooling from the intercritical annealing temperature to the isothermal holding temperature, (iii) the influence of the intercritically annealed austenite on the formation of bainite during the isothermal holding temperature, and (iv) the influence of the processing variables on the type, amount, composition and stability of the retained austenite. During this research study, techniques such as OM, SEM, EBSD, TEM, XRD and Magnetometry were used to fully characterize the microstructures. Furthermore, a Gleeble 3500 unit at US Steel Laboratories was used for dilatometry studies and to simulate different CGL processing routes, from which specimens were obtained to evaluate

  6. Aluminum and gallium arrest formation of cerebrospinal fluid by the mechanism of OH- depletion.

    PubMed

    Vogh, B P; Godman, D R; Maren, T H

    1985-06-01

    AlCl3 or GaCl3 was added to artificial cerebrospinal fluid and perfused through the cerebral ventricles of the rat. Depending on the metal and its concentration (1-10 mM) the pH of the perfusate ranged from 7.2 to 3.5. At 10 mM metal chloride, yielding pH 4.7 (Al) or 3.5 (Ga), formation of cerebrospinal fluid was suppressed 100%. The effect was reversed as soon as control cerebrospinal fluid (pH 7.35) was introduced. There was no effect at pH greater than 6 in the presence of metal ions nor was the effect mimicked by cerebrospinal fluid acidified with HCl or phosphate buffer to pH 4.7. HCl and phosphate at pH 4.7 had partial effects (25-30%). Inhibition of carbonic anhydrase is well known to have a partial effect (approximately 50%), the remainder of normal flow being dependent on the uncatalyzed formation of HCO3- and the corresponding movement of Na+. The complete cessation of flow after exposure to Al or Ga ions appears to occur when these ions are perfused at pH where they are partly hydrolyzed. Under these circumstances they form very powerful proton generating systems (as shown by titration data), which could lower [OH-] at the secretory border of choroid plexus cells. As a result, both the catalyzed and the uncatalyzed processes for formation of HCO3- from CO2 are abolished and secretion stops. This mechanism may also account for the antiperspirant action of Al salts. Using metal ion hydrolysis to probe other secretory systems will also be of interest.

  7. A thermodynamic prediction for microporosity formation in aluminum-rich Al-Cu alloys

    NASA Technical Reports Server (NTRS)

    Poirier, D. R.; Yeum, K.; Maples, A. L.

    1987-01-01

    A computer model is used to predict the formation and degree of microporosity in a directionally solidified Al-4.5 wt pct Cu alloy, considering the interplay between solidification shrinkage and gas porosity. Macrosegregation theory is used to determine the local pressure within the interdendritic liquid. Results show interdendritic porosity for initial hydrogen contents in the 0.03-1 ppm range, and none below contents of 0.03. An increase in either the thermal gradient or the solidification rate is show to decrease the amount of interdendritic porosity.

  8. Interface Formation During Fusion™ Casting of AA3003/AA4045 Aluminum Alloy Ingots

    NASA Astrophysics Data System (ADS)

    Di Ciano, Massimo; Caron, E. J. F. R.; Weckman, D. C.; Wells, M. A.

    2015-12-01

    Fusion™ casting is a unique Direct Chill continuous casting process whereby two different alloys can be cast simultaneously, producing a laminated ingot for rolling into clad sheet metal such as AA3003/AA4045 brazing sheet. Better understanding of the wetting and interface formation process during Fusion™ casting is required to further improve process yields and also explore use of other alloy systems for new applications. In this research, AA3003-core/AA4045-clad ingots were cast using a well-instrumented lab-scale Fusion™ casting system. As-cast Fusion™ interfaces were examined metallurgically and by mechanical testing. Computational fluid dynamic analyses of the FusionTM casts were also performed. It was shown that the liquid AA4045-clad alloy was able to successfully wet and create an oxide-free, metallurgical, and mechanically sound interface with the lightly oxidized AA3003-core shell material. Based on the results of this study, it is proposed that the bond formation process at the alloys interface during casting is a result of discrete penetration of AA4045 liquid at defects in the preexisting AA3003 oxide, dissolution of underlying AA3003 by liquid AA4045, and subsequent bridging between penetration sites. Spot exudation on the AA3003 chill cast surface due to remelting and inverse segregation may also improve the wetting and bonding process.

  9. Modeling of inverse segregation and porosity formation in directionally solidified aluminum alloys

    SciTech Connect

    Rousset, P.; Rappaz, M.; Hannart, B.

    1995-09-01

    A model has been developed which simulates inverse segregation and microporosity formation in directionally solidified alloys. Based upon a finite difference scheme, the model takes into account volume changes associated with density variations during solidification. The continuity equations for the mass, the solute, and the energy together with the Darcy equation describing the flow in the mushy zone are solved in a mixed Lagrangian-Eulerian representation. All nodal points within the liquid phase move with the fluid velocity, whereas nodes are fixed in space as soon as they are reached by dendrite tips. When the dendrite tips arrive at the end of the ingot, the remaining interdendritic liquid partially compensates for the solidification shrinkage occurring deeper within the volume. Since the size of the ingot remains fixed from that point on (absence of a purely liquid region), air (macroporosity) is introduced at the mesh points to satisfy the mass balance, starting from the top of the mushy zone. The formation of microporosity is also accounted for in the model through a calculation of local hydrogen segregation. Using this model, it is shown that inverse segregation decreases with increasing hydrogen content (or volume fraction of microporosity). The results of the simulation are compared with experimental results obtained on an Al-Cu alloy solidified under well-controlled directional conditions.

  10. Ultrafast electronic and vibrational dynamics in brominated aluminum corroles: Energy relaxation and triplet formation.

    PubMed

    Stensitzki, T; Yang, Y; Berg, A; Mahammed, A; Gross, Z; Heyne, K

    2016-07-01

    We combined femtosecond (fs) VIS pump-IR probe spectroscopy with fs VIS pump-supercontinuum probe spectroscopy to characterize the photoreaction of the hexacoordinated Al(tpfc-Br8)(py)2 in a comprehensive way. Upon fs excitation at ∼400 nm in the Soret band, the excitation energy relaxes with a time constant of (250 ± 80) fs to the S2 and S1 electronic excited states. This is evident from the rise time of the stimulated emission signal in the visible spectral range. On the same time scale, narrowing of broad infrared signals in the C=C stretching region around 1500 cm(-1) is observed. Energy redistribution processes are visible in the vibrational and electronic dynamics with time constants between ∼2 ps and ∼20 ps. Triplet formation is detected with a time constant of (95 ± 3) ps. This is tracked by the complete loss of stimulated emission. Electronic transition of the emerging triplet absorption band overlaps considerably with the singlet excited state absorption. In contrast, two well separated vibrational marker bands for triplet formation were identified at 1477 cm(-1) and at 1508 cm(-1). These marker bands allow a precise identification of triplet dynamics in corrole systems. PMID:27226980

  11. Ultrafast electronic and vibrational dynamics in brominated aluminum corroles: Energy relaxation and triplet formation

    PubMed Central

    Stensitzki, T.; Yang, Y.; Berg, A.; Mahammed, A.; Gross, Z.; Heyne, K.

    2016-01-01

    We combined femtosecond (fs) VIS pump–IR probe spectroscopy with fs VIS pump–supercontinuum probe spectroscopy to characterize the photoreaction of the hexacoordinated Al(tpfc-Br8)(py)2 in a comprehensive way. Upon fs excitation at ∼400 nm in the Soret band, the excitation energy relaxes with a time constant of (250 ± 80) fs to the S2 and S1 electronic excited states. This is evident from the rise time of the stimulated emission signal in the visible spectral range. On the same time scale, narrowing of broad infrared signals in the C=C stretching region around 1500 cm−1 is observed. Energy redistribution processes are visible in the vibrational and electronic dynamics with time constants between ∼2 ps and ∼20 ps. Triplet formation is detected with a time constant of (95 ± 3) ps. This is tracked by the complete loss of stimulated emission. Electronic transition of the emerging triplet absorption band overlaps considerably with the singlet excited state absorption. In contrast, two well separated vibrational marker bands for triplet formation were identified at 1477 cm−1 and at 1508 cm−1. These marker bands allow a precise identification of triplet dynamics in corrole systems. PMID:27226980

  12. Silicon nitride-aluminum oxide solid solution (SiAION) formation and densification by pressure sintering

    NASA Technical Reports Server (NTRS)

    Yeh, H. C.; Sanders, W. A.; Fiyalko, J. L.

    1975-01-01

    Stirred-ball-mill-blended Si3N4 and Al2O3 powders were pressure sintered in order to investigate the mechanism of solid solution formation and densification in the Si3N4-Al2O3 system. Powder blends with Si3N4:Al2O3 mole ratios of 4:1, 3:2, and 2:3 were pressure sintered at 27.6-MN/sq m pressure at temperatures to 17000 C (3090 F). The compaction behavior of the powder blends during pressure sintering was determined by observing the density of the powder compact as a function of temperature and time starting from room temperature. This information, combined with the results of X-ray diffraction and metallographic analyses regarding solutioning and phase transformation phenomena in the Si3N4-Al2O3 system, was used to describe the densification behavior.

  13. Spontaneous formation of complex structures made from elastic membranes in an aluminum-hydroxide-carbonate system

    NASA Astrophysics Data System (ADS)

    Kiehl, Micah; Kaminker, Vitaliy; Pantaleone, James; Nowak, Piotr; Dyonizy, Agnieszka; Maselko, Jerzy

    2015-06-01

    A popular playground for studying chemo-hydrodynamic patterns and instabilities is chemical gardens, also known as silicate gardens. In these systems, complex structures spontaneously form, driven by buoyant forces and either osmotic or mechanical pumps. Here, we report on systems that differ somewhat from classical chemical gardens in that the membranes are much more deformable and soluble. These properties lead to structures that self-construct and evolve in new ways. For example, they exhibit the formation of chemical balloons, a new growth mechanism for tubes, and also the homologous shrinking of these tubes. The stretching mechanism for the membranes is probably different than for other systems by involving membrane "self-healing." Other unusual properties are osmosis that sometimes occurs out of the structure and also small plumes that flow away from the structure, sometimes upwards, and sometimes downwards. Mathematical models are given that explain some of the observed phenomena.

  14. Heats of formation of complex halo anions of aluminum and gallium

    SciTech Connect

    Gavrilin, E.N.; Skokan, E.V.; Sorokin, I.D.

    1988-01-01

    The heats of formation of the gaseous anions MF/sub 3/X/sup -/ (M = Al, Ga; X = Cl, Br, I) have been determined by the Knudsen method with mass-spectrometric analysis of the gaseous phase. They are ..delta../sub f/H/sub 0//sup 0/(AlF/sub 3/Cl/sup -/) = -1726 +/- 15, ..delta../sub f/H/sub 0//sup 0/(AlF/sub 3/Br/sup -/) = -1674 +/- 15, ..delta../sub f/H/sub 0//sup 0/(AlF/sub 3/I/sup -/) = -1612 +/- 15, ..delta../sub f/H/sub 0//sup 0/(GaF/sub 3/Cl/sup -/) = -1397, ..delta../sub f/H/sub 0//sup 0/(GaF/sub 3/Br/sup -/) = -1335 +/- 30, and ..delta../sub f/H/sub 0//sup 0/(GaF/sub 3/I/sup -/) = -1290 +/- 30 kJ/mole. The energies of the MF/sub 3/-X/sup -/ bonds have been calculated.

  15. FORMATION OF CHROMATE CONVERSION COATINGS ON ALUMINUM AND ITS ALLOYS: AN IN SITU XANES STUDY.

    SciTech Connect

    SASAKI,K.; ISAACS,H.S.; JAFFCOATE,C.S.; BUCHHAIT,R.; LEGAT,V.; LEE,H.; SRINIVASAMURTHI,V.

    2001-09-02

    We used in situ X-ray adsorption near-edge structure (XANES) to investigate the formation of chromate conversion coatings on pure Al, commercial Al alloys (AA 1100, AA2024, and AA7075), and a series of binary Al-Cu alloys. The method employed a new electrochemical cell that can determine the ratio of hexavalent chromium (Cr(VI)) to total chromium (Cr(total)) speciation in conversion coatings as a function of exposure time to a chromate solution. The spectra showed that the initial Cr(VI)/Cr(total) ratios are greater than later ones for pure Al and AA1100, but not for AA2024 and AA7075. Measurements with Al-Cu alloys demonstrated that the difference observed in AA2024 and AA7075 may not be due to Cu alloying. The proportion of Cr(VI) in the coatings becomes approximately constant after 180 s of exposure for all the specimens examined even though the coatings continue to grow.

  16. Aluminum colloid formation and its effect on co-precipitation of zinc during acid rock drainage remediation with clinoptilolite in a slurry bubble column

    NASA Astrophysics Data System (ADS)

    Xu, W.; Li, L. Y.; Grace, J. R.

    2012-04-01

    Zinc and other metal ions were adsorbed in a laboratory slurry bubble column (SBC) by natural clinoptilolite sorbent particles. During the remediation process, significant white precipitates were sometimes observed. Both zinc and aluminum were detected in the colloidal mixtures. It is shown that Al leached from clinoptilolite during the agitation, contributing to the precipitate. As a result of the Al leaching and increase of pH during the remediation process, the formation of an Al colloid and zinc adsorption onto it could significantly improve ARD remediation, given the high adsorption capacity of the colloid. Sorption of cations increased with increasing colloid formation. Various conditions were tested to investigate their impact on (a) dealumination of clinoptilolite; (b) Al hydrolysis/colloid formation; and (c) adsorption onto the colloidal mixture. The test results indicate that dealumination contributes to the excess aluminum in the aqueous phase and to precipitates. The excess dealumination varies with pH and agitation time. Al hydrolysis occurs with increasing pH due to the neutralization effect of clinoptilolite. A significant proportion of zinc adsorbed onto the collectible aluminum precipitates.

  17. Formation and breakdown of chromate conversion coatings on aluminum-zinc-magnesium-copper 7X75 alloys

    NASA Astrophysics Data System (ADS)

    Yoon, Yuhchae

    The objective of this study was to characterize the formation and breakdown of chromate conversion coatings (CCCs) on aluminum alloys Al-Zn-Mg-Cu 7075 and 7475 with a focus on the effect of alloy temper, alloy purity and selected coating processing variables. Overall, results consistently pointed to a slight temper effect. Conversion coated AA7475-T7 was significantly more corrosion resistant than conversion coated AA7475-T6. In AA7075, there was only a slight difference in corrosion resistance between the two tempers. This was attributed to the effect of constituent particles on coating formation and breakdown, which are present to a much greater extent in AA7075 than in AA7475. The difference in the corrosion resistance between the T6 and T7 tempers in the coated and uncoated conditions is about the same suggesting that the origin of any "temper effect" in conversion coated materials is ultimately due to the intrinsic change in corrosion susceptibility of the alloy itself. Thicker coating formed on AA7475-T7 has the effect of increasing corrosion resistance, which could be associated with the 860 cm-1 Raman intensity band. Studies were also conducted with alloys in retrogression and reaged tempers and the W temper. Results with these tempers were mixed and no general conclusions could be drawn. In terms of electrochemically derived measures of corrosion resistance (electrochemical impedance, and pitting potential measurements), the magnitude of the temper effect was about the same as the effect due to the purity difference between AA7075 and AA7475. The temper effect was less significant than effects due to increasing coating time from 1 to 3 minutes, withholding certain substrate precleaning steps, or withholding key ingredients from the coating bath. Scanning probe microscopy, scanning Kelvin probe force microscopy (SKPFM) and scanning electron microscopy were used to characterize coating formation in the vicinity of constituent intermetallic particles (IMPs

  18. Dynamics of plasma expansion and shockwave formation in femtosecond laser-ablated aluminum plumes in argon gas at atmospheric pressures

    SciTech Connect

    Miloshevsky, Alexander; Harilal, Sivanandan S.; Miloshevsky, Gennady Hassanein, Ahmed

    2014-04-15

    Plasma expansion with shockwave formation during laser ablation of materials in a background gasses is a complex process. The spatial and temporal evolution of pressure, temperature, density, and velocity fields is needed for its complete understanding. We have studied the expansion of femtosecond (fs) laser-ablated aluminum (Al) plumes in Argon (Ar) gas at 0.5 and 1 atmosphere (atm). The expansion of the plume is investigated experimentally using shadowgraphy and fast-gated imaging. The computational fluid dynamics (CFD) modeling is also carried out. The position of the shock front measured by shadowgraphy and fast-gated imaging is then compared to that obtained from the CFD modeling. The results from the three methods are found to be in good agreement, especially during the initial stage of plasma expansion. The computed time- and space-resolved fields of gas-dynamic parameters have provided valuable insights into the dynamics of plasma expansion and shockwave formation in fs-pulse ablated Al plumes in Ar gas at 0.5 and 1 atm. These results are compared to our previous data on nanosecond (ns) laser ablation of Al [S. S. Harilal et al., Phys. Plasmas 19, 083504 (2012)]. It is observed that both fs and ns plumes acquire a nearly spherical shape at the end of expansion in Ar gas at 1 atm. However, due to significantly lower pulse energy of the fs laser (5 mJ) compared to pulse energy of the ns laser (100 mJ) used in our studies, the values of pressure, temperature, mass density, and velocity are found to be smaller in the fs laser plume, and their time evolution occurs much faster on the same time scale. The oscillatory shock waves clearly visible in the ns plume are not observed in the internal region of the fs plume. These experimental and computational results provide a quantitative understanding of plasma expansion and shockwave formation in fs-pulse and ns-pulse laser ablated Al plumes in an ambient gas at atmospheric pressures.

  19. Effects of filling material and laser power on the formation of intermetallic compounds during laser-assisted friction stir butt welding of steel and aluminum alloys

    NASA Astrophysics Data System (ADS)

    Fei, Xinjiang; Jin, Xiangzhong; Peng, Nanxiang; Ye, Ying; Wu, Sigen; Dai, Houfu

    2016-11-01

    In this paper, two kinds of materials, Ni and Zn, are selected as filling material during laser-assisted friction stir butt welding of Q235 steel and 6061-T6 aluminum alloy, and their influences on the formation of intermetallic compounds on the steel/aluminum interface of the joints were first studied. SEM was used to analyze the profile of the intermetallic compound layer and the fractography of tensile fracture surfaces. In addition, EDS was applied to investigate the types of the intermetallic compounds. The results indicate that a thin iron-abundant intermetallic compound layer forms and ductile fracture mode occurs when Ni is added, but a thick aluminum-abundant intermetallic compound layer generates and brittle fracture mode occurs when Zn is added. So the tensile strength of the welds with Ni as filling material is greater than that with Zn as filling material. Besides, the effect of laser power on the formation of intermetallic compound layer when Ni is added was investigated. The preheated temperature field produced by laser beam in the cross section of workpiece was calculated, and the tensile strength of the joints at different laser powers was tested. Results show that only when suitable laser power is adopted, can suitable preheating temperature of the steel reach, then can thin intermetallic compound layer form and high tensile strength of the joints reach. Either excessive or insufficient laser power will reduce the tensile strength of the joints.

  20. Influence of different parameter profiles on the formation of aluminum back surface field (Al-BSF) using for HIT solar cell

    NASA Astrophysics Data System (ADS)

    Zeng, Xiangbin; Zeng, Yu; AL-Naser, Qusay Assim Hanna; Zhou, Chunlan; Zhang, Xiao; Chen, Qiankun; Yang, Yanyan; Liu, Luo

    2009-08-01

    The aluminum back surface field used in p-type substrate hetero-junction with intrinsic thin film (HIT) solar cell is studied in this paper. The enhancement of material quality and the decrease of wafer thickness will make it necessary to passivate the back surface. It simply states the principle and formation process of aluminum back surface field, and studies the evenness of back surface field because it is necessary for high efficiency solar cell. Screen-printing and rapid thermal annealing were used to make aluminum back surface field to gain low recombination on the backside of solar cells. In this experiment, we analyze Al-BSF formed by taking different times and temperatures in which the temperature varied in the range between 620°C and 940 °C step 80°C and the time varied from 60 seconds to 180 seconds with a step of 30 seconds. Minority carrier lifetime with the back surface field was measured by microwave photoconductive decay (μ-PCD) device, analyze and get the optimal parameters of forming Al-BSF and further improve conversion efficiency of silicon solar cell.

  1. Influence of Gas Composition and Exposure Cycle on the Formation of Surface and Subsurface Oxides in Iron-Aluminum-Based Alloys at High Temperatures

    NASA Astrophysics Data System (ADS)

    Bott, June H.; Yin, Hogbin; Sridhar, Seetharaman; Auinger, Michael

    2016-08-01

    The slab reheating process of binary iron-aluminum alloys and an industrial TRIP steel grade has been investigated in both dry and wet atmospheres. The presence of water vapor has a significant effect on the overall scale growth and internal corrosion depth. Heating rate greatly influences the porosity of the surface oxide layer with the surface getting more porous at faster heating rates. Nitride formation could be suppressed in the presence of water vapor, leading to a reduction of internal corrosion depth and a better formability of the final material. Experimental results were compared to thermodynamic predictions and critically discussed.

  2. Conference Resolution

    NASA Astrophysics Data System (ADS)

    2009-04-01

    Since the first IUPAP International Conference on Women in Physics (Paris, March 2002) and the Second Conference (Rio de Janeiro, May 2005), progress has continued in most countries and world regions to attract girls to physics and advance women into leadership roles, and many working groups have formed. The Third Conference (Seoul, October 2008), with 283 attendees from 57 countries, was dedicated to celebrating the physics achievements of women throughout the world, networking toward new international collaborations, building each participant's capacity for career success, and aiding the formation of active regional working groups to advance women in physics. Despite the progress, women remain a small minority of the physics community in most countries.

  3. 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 ...

  4. Cage structure formation of singly doped aluminum cluster cations Al(n)TM+ (TM = Ti, V, Cr).

    PubMed

    Lang, Sandra M; Claes, Pieterjan; Neukermans, Sven; Janssens, Ewald

    2011-09-01

    Structural information on free transition metal doped aluminum clusters, Al(n)TM(+) (TM = Ti, V, Cr), was obtained by studying their ability for argon physisorption. Systematic size (n = 5-35) and temperature (T = 145-300 K) dependent investigations reveal that bare Al(n)(+) clusters are inert toward argon, while Al(n)TM(+) clusters attach one argon atom up to a critical cluster size. This size is interpreted as the geometrical transition from surface-located dopant atoms to endohedrally doped aluminum clusters with the transition metal atom residing in an aluminum cage. The critical size, n(crit), is found to be surprisingly large, namely n(crit) = 16 and n(crit) = 19-21 for TM = V, Cr, and TM = Ti, respectively. Experimental cluster-argon bond dissociation energies have been derived as function of cluster size from equilibrium mass spectra and are in the 0.1-0.3 eV range.

  5. A first-principles investigation of the effect of relaxation on the alloy formation in the aluminum-3 d-transition-metal system

    NASA Astrophysics Data System (ADS)

    Nikitin, N. Yu.

    2012-05-01

    The aim of this investigation is to establish the effect of relaxation on the formation of ordered substitutional solid solutions in Al1 - x M x alloys ( M = 3 d metal; x = 1.6 at %). As the main parameters of the process of formation of the aluminum-based solution, thermodynamic quantities such as the energy of dissolution and the cohesive energy have been chosen; for choosing the most appropriate substitutional element, an analysis of the relaxation energy and deviations of empirical atomic radii of the impurity from the radius of the matrix-forming element has been suggested. It has been shown that there is a correlation between these thermodynamic quantities through the behavior of the density of electronic states and the Fermi energy. A regular relation has also been demonstrated to exist between the relaxation and stability of arising solid solutions, which supports the applicability of the analysis of relaxation energy depending on the atomic radius of the matrix-substituting element. The presence of anomalies in the behavior of magnetic properties of some aluminum alloys with transition metals has been shown and their explanation is given.

  6. Synergy between Multiple Microtubule-Generating Pathways Confers Robustness to Centrosome-Driven Mitotic Spindle Formation

    PubMed Central

    Hayward, Daniel; Metz, Jeremy; Pellacani, Claudia; Wakefield, James G.

    2014-01-01

    Summary The mitotic spindle is defined by its organized, bipolar mass of microtubules, which drive chromosome alignment and segregation. Although different cells have been shown to use different molecular pathways to generate the microtubules required for spindle formation, how these pathways are coordinated within a single cell is poorly understood. We have tested the limits within which the Drosophila embryonic spindle forms, disrupting the inherent temporal control that overlays mitotic microtubule generation, interfering with the molecular mechanism that generates new microtubules from preexisting ones, and disrupting the spatial relationship between microtubule nucleation and the usually dominant centrosome. Our work uncovers the possible routes to spindle formation in embryos and establishes the central role of Augmin in all microtubule-generating pathways. It also demonstrates that the contributions of each pathway to spindle formation are integrated, highlighting the remarkable flexibility with which cells can respond to perturbations that limit their capacity to generate microtubules. PMID:24389063

  7. Rigorous simulation of OCT image formation using Maxwell's equations in three dimensions (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Munro, Peter R. T.; Curatolo, Andrea; Sampson, David D.

    2016-03-01

    Existing models of image formation in optical coherence tomography are based upon the extended Huygens-Fresnel formalism. These models all, to varying degrees, rely on scatterer ensemble averages, rather than deterministic scattering distributions. Whilst the former is sometimes preferable, there are a growing number of applications where the ability to predict image formation based upon deterministic refractive index distributions is of great interest, including, for example, image formation in turbid tissue. A rigorous model based upon three-dimensional solutions of Maxwell's equations offers a number of tantalising opportunities. For example, shedding light on features near or below the resolution of an OCT system and on the impact of phenomena usually described as diffraction, interference and scattering, but which more generally result from light scattering satisfying Maxwell's equations. A rigorous model allows inverse scattering methods to be developed not requiring the first-order Born approximation. Finally, a rigorous model can provide gold standard verification of myriad quantitative techniques currently being developed throughout the field. We have developed the first such model of image formation based upon three-dimensional solutions of Maxwell's equations, which has vastly different properties to models based on two-dimensional solutions. Although we present simulated B-scans, this model is equally applicable to C-scans. This has been made possible by advances in computational techniques and in computational resources routinely available. We will present the main features of our model, comparisons of measured and simulated image formation for phantoms and discuss the future of rigorous modelling in optical coherence tomography research and application.

  8. Teacher Perceptions about Observation Conferences: What Do Teachers Think about Their Formative Supervision in One US School District?

    ERIC Educational Resources Information Center

    Range, Bret G.; Young, Suzie; Hvidston, David

    2013-01-01

    This study measured teachers' perceptions about the important elements of the pre- and post-observation conferences within one school district in a US state. Overall, respondents valued the post-observation conference more than the pre-observation conference and identified trusting relationships, constructive feedback, reflection and areas of…

  9. Isoniazid-resistance conferring mutations in Mycobacterium tuberculosis KatG: Catalase, peroxidase, and INH-NADH adduct formation activities

    PubMed Central

    Cade, Christine E; Dlouhy, Adrienne C; Medzihradszky, Katalin F; Salas-Castillo, Saida Patricia; Ghiladi, Reza A

    2010-01-01

    Mycobacterium tuberculosis catalase-peroxidase (KatG) is a bifunctional hemoprotein that has been shown to activate isoniazid (INH), a pro-drug that is integral to frontline antituberculosis treatments. The activated species, presumed to be an isonicotinoyl radical, couples to NAD+/NADH forming an isoniazid-NADH adduct that ultimately confers anti-tubercular activity. To better understand the mechanisms of isoniazid activation as well as the origins of KatG-derived INH-resistance, we have compared the catalytic properties (including the ability to form the INH-NADH adduct) of the wild-type enzyme to 23 KatG mutants which have been associated with isoniazid resistance in clinical M. tuberculosis isolates. Neither catalase nor peroxidase activities, the two inherent enzymatic functions of KatG, were found to correlate with isoniazid resistance. Furthermore, catalase function was lost in mutants which lacked the Met-Tyr-Trp crosslink, the biogenic cofactor in KatG which has been previously shown to be integral to this activity. The presence or absence of the crosslink itself, however, was also found to not correlate with INH resistance. The KatG resistance-conferring mutants were then assayed for their ability to generate the INH-NADH adduct in the presence of peroxide (t-BuOOH and H2O2), superoxide, and no exogenous oxidant (air-only background control). The results demonstrate that residue location plays a critical role in determining INH-resistance mechanisms associated with INH activation; however, different mutations at the same location can produce vastly different reactivities that are oxidant-specific. Furthermore, the data can be interpreted to suggest the presence of a second mechanism of INH-resistance that is not correlated with the formation of the INH-NADH adduct. PMID:20054829

  10. The detection of tightly closed flaws by nondestructive testing (NDT) methods. [fatigue crack formation in aluminum alloy test specimens

    NASA Technical Reports Server (NTRS)

    Rummel, W. D.; Rathke, R. A.; Todd, P. H., Jr.; Mullen, S. J.

    1975-01-01

    Liquid penetrant, ultrasonic, eddy current and X-radiographic techniques were optimized and applied to the evaluation of 2219-T87 aluminum alloy test specimens in integrally stiffened panel, and weld panel configurations. Fatigue cracks in integrally stiffened panels, lack-of-fusion in weld panels, and fatigue cracks in weld panels were the flaw types used for evaluation. A 2319 aluminum alloy weld filler rod was used for all welding to produce the test specimens. Forty seven integrally stiffened panels containing a total of 146 fatigue cracks, ninety three lack-of-penetration (LOP) specimens containing a total of 239 LOP flaws, and one-hundred seventeen welded specimens containing a total of 293 fatigue cracks were evaluated. Nondestructive test detection reliability enhancement was evaluated during separate inspection sequences in the specimens in the 'as-machined or as-welded', post etched and post proof loaded conditions. Results of the nondestructive test evaluations were compared to the actual flaw size obtained by measurement of the fracture specimens after completing all inspection sequences. Inspection data were then analyzed to provide a statistical basis for determining the flaw detection reliability.

  11. Analysis of the effects of microalloying on glass formation in aluminum-yttrium-iron alloys by fluctuation electron microscopy and other techniques

    NASA Astrophysics Data System (ADS)

    Bondi, Karyn Spence

    Metallic glasses offer enhanced properties in processing and wear over their crystalline counterparts. Aluminum-based metallic glasses are further desired for their high strength-to-weight ratio and low cost. It has been observed that additions of very small amounts of additional elements to the base aluminum-based alloys can dramatically improve glass formability. Here, the effects of microalloying on glass formation and stability are systematically investigated by substituting 0.5 atomic percent of all 3-d transition metals for Al in Al88Y7Fe5 alloys. X-ray diffraction, differential scanning calorimetry, differential thermal analysis, and transmission electron microscopy studies demonstrate enhanced glassy characteristics and stability in the microalloys. Further collaborative investigations using high-energy synchrotron X-ray diffraction, extended X-ray absorption fine structure analysis, and atom probe tomography reveal enhanced short- and medium-range order as well as a suppression of phase separation upon microalloying. A novel investigation method, fluctuation electron microscopy, was employed to quantify the extent of medium range order in the alloys by statistical analysis of microdiffraction patterns. Significant enhancements were made to the methodological protocol for this new technique, allowing for greatly enhanced experimental reproducibility.

  12. Flocculation kinetics mechanism and floc formation prepared by poly aluminum chloride coupled with polyacrylamide for ship ballast water.

    PubMed

    Zhou, Zhimin; Liu, Sha; Jia, Linan

    2016-01-01

    The performance of flocculants prepared by poly aluminum chloride (PAC) and polyacrylamide (PAM) on treating ballast water collected at the Dalian new port area, the evaluation depending on the values of reaction parameters, and kinetics mechanism of flocculation were investigated in this study. Accordingly, the flocculants of 0.1 g·L(-1), prepared by mixing PAC of 10% with PAM of 2.0‰, enabled the removal rate of zooplankton and phytoplankton to reach 91% in ballast water at 20 °C. Based on flocculation kinetics mechanism analysis, the efficient vortex size during stirring should be larger than the floc particles, and gradient of fluctuating velocity provide the impetus for turbulence flocculation. The results of this study could be relevant to understanding particle-floc interactions during developmental flocculation, and during application of ballast water treatment.

  13. Flocculation kinetics mechanism and floc formation prepared by poly aluminum chloride coupled with polyacrylamide for ship ballast water.

    PubMed

    Zhou, Zhimin; Liu, Sha; Jia, Linan

    2016-01-01

    The performance of flocculants prepared by poly aluminum chloride (PAC) and polyacrylamide (PAM) on treating ballast water collected at the Dalian new port area, the evaluation depending on the values of reaction parameters, and kinetics mechanism of flocculation were investigated in this study. Accordingly, the flocculants of 0.1 g·L(-1), prepared by mixing PAC of 10% with PAM of 2.0‰, enabled the removal rate of zooplankton and phytoplankton to reach 91% in ballast water at 20 °C. Based on flocculation kinetics mechanism analysis, the efficient vortex size during stirring should be larger than the floc particles, and gradient of fluctuating velocity provide the impetus for turbulence flocculation. The results of this study could be relevant to understanding particle-floc interactions during developmental flocculation, and during application of ballast water treatment. PMID:27386983

  14. A force sensor using nanowire arrays to understand biofilm formation (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Sahoo, Prasana K.; Cavalli, Alessandro; Pelegati, Vitor B.; Murillo, Duber M.; Souza, Alessandra A.; Cesar, Carlos L.; Bakkers, Erik P. A. M.; Cotta, Monica A.

    2016-03-01

    Understanding the cellular signaling and function at the nano-bio interface can pave the way towards developing next-generation smart diagnostic tools. From this perspective, limited reports detail so far the cellular and subcellular forces exerted by bacterial cells during the interaction with abiotic materials. Nanowire arrays with high aspect ratio have been used to detect such small forces. In this regard, live force measurements were performed ex-vivo during the interaction of Xylella fastidiosa bacterial cells with InP nanowire arrays. The influence of nanowire array topography and surface chemistry on the response and motion of bacterial cells was studied in detail. The nanowire arrays were also functionalized with different cell adhesive promoters, such as amines and XadA1, an afimbrial protein of X.fastidiosa. By employing the well-defined InP nanowire arrays platform, and single cell confocal imaging system, we were able to trace the bacterial growth pattern, and show that their initial attachment locations are strongly influenced by the surface chemistry and nanoscale surface topography. In addition, we measure the cellular forces down to few nanonewton range using these nanowire arrays. In case of nanowire functionalized with XadA1, the force exerted by vertically and horizontally attached single bacteria on the nanowire is in average 14% and 26% higher than for the pristine array, respectively. These results provide an excellent basis for live-cell force measurements as well as unravel the range of forces involved during the early stages of bacterial adhesion and biofilm formation.

  15. Aluminum Corrosion and Turbidity

    SciTech Connect

    Longtin, F.B.

    2003-03-10

    Aluminum corrosion and turbidity formation in reactors correlate with fuel sheath temperature. To further substantiate this correlation, discharged fuel elements from R-3, P-2 and K-2 cycles were examined for extent of corrosion and evidence of breaking off of the oxide film. This report discusses this study.

  16. Peculiarities of the rheological behavior and structure formation of aluminum under deformation at near-solidus temperatures

    NASA Astrophysics Data System (ADS)

    Smirnov, A. S.; Konovalov, A. V.; Belozerov, G. A.; Shveikin, V. P.; Smirnova, E. O.

    2016-05-01

    This paper deals with a peculiar rheological behavior of aluminum at near-solidus temperatures. It has been experimentally established that there is an inverse strain rate dependence of strain resistance at temperatures ranging between 560 and 640°C and strain rates ranging from 0.06 to 1.2 s-1. Electron backscatter diffraction analysis has shown that at temperatures ranging between 540 and 640°C and strain rates ranging from 0.06 to 0.1 s-1, the main process of softening is dynamic polygonization, resulting in in situ recrystallization. At higher strain rates, ranging between 0.8 and 1.2 s-1, and temperatures ranging between 560 and 640°C, the recovery is dynamic. This unusual behavior of the mechanism of softening and the presence of the inverse strain rate dependence of strain resistance can be explained by blocking the motion of free dislocations by foreign atoms, which occurs at strain rates ranging between 0.06 and 0.1 s-1. This process results in dislocation pile-up, thereby causing in situ recrystallization. At strain rates exceeding 0.16 s-1, there is no intensive blocking of dislocations, leading to a direct strain rate dependence of strain resistance.

  17. Aluminum: Aluminum Scrap Decoater

    SciTech Connect

    Blazek, S.

    1999-01-29

    NICE3 and the Philip Services Corporation are cost-sharing a demonstration project to decoat metal using indirect-fired controlled-atmosphere (IDEX) kilns, which can both process solid organics such as rubber and plastics, and minimize dust formation and emission of volatile organic compounds. The publication explains how this cost-effective, two-step system operates.

  18. Correlating shaped charge performance with processing conditions and microstructure of an aluminum alloy 1100 liner enabled by a new method to arrest nascent jet formation

    NASA Astrophysics Data System (ADS)

    Scheid, James Eric

    Aluminum-lined shaped charges are used in special applications where jet and / or slug residue in the target is undesired. The three different microstructures of the aluminum liners studied herein resulted from three different manufacturing interpretations of the same design. One interpretation was completely machining the liners from best available annealed round stock. The second was to cold-forge the liners from annealed round-stock in an open-die forge to near-final dimensions, and then machine the liners to the final dimensions. The third variant in this study was to use the above forged liner, but with annealing after the machining. These three manufacturing choices resulted in significant variations in shaped charge performance. The goal of this research was to clarify the relationships between the liner metal microstructure and properties, and the corresponding shaped charge dynamic flow behavior. What began as an investigation into user-reported performance problems associated inherently with liner manufacturing processes and resultant microstructure, resolved into new understandings of the relationships between aluminum liner microstructure and shaped charge collapse kinetics. This understanding was achieved through an extensive literature review and the comprehensive characterization of the material properties of three variants of an 1100 aluminum shaped charge liner with a focus on collapse and nascent jet formation. The machined liner had a microstructure with large millimeter-sized grains and fine particles aligned in bands parallel to the charge axis. The forged liner microstructure consisted of very small one micrometer-sized (1 mum) subgrains and fine particles aligned largely in bands elongated parallel to the liner contour. The annealed liner was characterized by ten micrometer (10 mum) sized equiaxed grains with residual fine particles in the forged alignment. This characterization was enabled by the development, execution and validation of a

  19. 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.

  20. 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.

  1. First principles calculations of formation energies and elastic constants of inclusions α-Al2O3, MgO and AlN in aluminum alloy

    NASA Astrophysics Data System (ADS)

    Liu, Yu; Huang, Yuanchun; Xiao, Zhengbing; Yang, Chuge; Reng, Xianwei

    2016-05-01

    In this paper, the formation energies and elastic constants of α-Al2O3, MgO and AlN in both rock salt (cubic) and wurtzite (hexagonal) structures were investigated by first principles calculations. The results show that the formation energy being -17.8, -6.3, -3.06 and -3.46 eV/formula unit for α-Al2O3, MgO, AlN (rock salt) and AlN (wurtzite). It suggests that in the ground state, α-Al2O3 is relatively more stable than MgO and AlN. The elastic properties for a polycrystalline in the ground state were calculated with the obtained elastic constants, the elastic properties reveal the rock salt structure AlN is the hardest particles among all the inclusions, and all of these inclusions are classified as brittle materials, which is detrimental to the ductile nature of aluminum matrix. The calculated anisotropy index shows that the AlN (wurtzite) and α-Al2O3 have a lower degree of anisotropy compared with MgO and AlN (rock salt). The calculated results are in good agreement with the values of experimental and other works.

  2. Formulation and method for preparing gels comprising hydrous aluminum oxide

    SciTech Connect

    Collins, Jack L.

    2014-06-17

    Formulations useful for preparing hydrous aluminum oxide gels contain a metal salt including aluminum, an organic base, and a complexing agent. Methods for preparing gels containing hydrous aluminum oxide include heating a formulation to a temperature sufficient to induce gel formation, where the formulation contains a metal salt including aluminum, an organic base, and a complexing agent.

  3. In-situ Quasi-Instantaneous e-beam Driven Catalyst-Free Formation Of Crystalline Aluminum Borate Nanowires

    PubMed Central

    Gonzalez-Martinez, Ignacio G.; Gemming, Thomas; Mendes, Rafael; Bachmatiuk, Alicja; Bezugly, Viktor; Kunstmann, Jens; Eckert, Jürgen; Cuniberti, Gianaurelio; Rümmeli, Mark H.

    2016-01-01

    The catalyst-assisted nucleation and growth mechanisms for many kinds of nanowires and nanotubes are pretty well understood. At times, though, 1D nanostructures form without a catalyst and the argued growth modes have inconsistencies. One such example is the catalyst-free growth of aluminium borate nanowires. Here we develop an in-situ catalyst-free room temperature growth route for aluminium nanowires using the electron beam in a transmission electron microscope. We provide strong experimental evidence that supports a formation process that can be viewed as a phase transition in which the generation of free-volume induced by the electron beam irradiation enhances the atomic mobility within the precursor material. The enhanced atomic mobility and specific features of the crystal structure of Al5BO9 drive the atomic rearrangement that results in the large scale formation of highly crystalline aluminium borate nanowires. The whole formation process can be completed within fractions of a second. Our developed growth mechanism might also be extended to describe the catalyst-free formation of other nanowires. PMID:26934833

  4. In-situ Quasi-Instantaneous e-beam Driven Catalyst-Free Formation Of Crystalline Aluminum Borate Nanowires.

    PubMed

    Gonzalez-Martinez, Ignacio G; Gemming, Thomas; Mendes, Rafael; Bachmatiuk, Alicja; Bezugly, Viktor; Kunstmann, Jens; Eckert, Jürgen; Cuniberti, Gianaurelio; Rümmeli, Mark H

    2016-01-01

    The catalyst-assisted nucleation and growth mechanisms for many kinds of nanowires and nanotubes are pretty well understood. At times, though, 1D nanostructures form without a catalyst and the argued growth modes have inconsistencies. One such example is the catalyst-free growth of aluminium borate nanowires. Here we develop an in-situ catalyst-free room temperature growth route for aluminium nanowires using the electron beam in a transmission electron microscope. We provide strong experimental evidence that supports a formation process that can be viewed as a phase transition in which the generation of free-volume induced by the electron beam irradiation enhances the atomic mobility within the precursor material. The enhanced atomic mobility and specific features of the crystal structure of Al5BO9 drive the atomic rearrangement that results in the large scale formation of highly crystalline aluminium borate nanowires. The whole formation process can be completed within fractions of a second. Our developed growth mechanism might also be extended to describe the catalyst-free formation of other nanowires. PMID:26934833

  5. 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)

  6. Silico-ferrite of Calcium and Aluminum (SFCA) Iron Ore Sinter Bonding Phases: New Insights into Their Formation During Heating and Cooling

    NASA Astrophysics Data System (ADS)

    Webster, Nathan A. S.; Pownceby, Mark I.; Madsen, Ian C.; Kimpton, Justin A.

    2012-12-01

    The formation of silico-ferrite of calcium and aluminum (SFCA) and SFCA-I iron ore sinter phases during heating and cooling of synthetic iron ore sinter mixtures in the range 298 K to 1623 K (25 °C to 1350 °C) and at oxygen partial pressure of 5 × 10-3 atm has been characterized using in situ synchrotron X-ray diffraction. SFCA and SFCA-I are the key bonding phases in iron ore sinter, and an improved understanding of their formation mechanisms may lead to improved efficiency of industrial sintering processes. During heating, SFCA-I formation at 1327 K to 1392 K (1054 °C to 1119 °C) (depending on composition) was associated with the reaction of Fe2O3, 2CaO·Fe2O3, and SiO2. SFCA formation (1380 K to 1437 K [1107 °C to 1164 °C]) was associated with the reaction of CaO·Fe2O3, SiO2, and a phase with average composition 49.60, 9.09, 0.14, 7.93, and 32.15 wt pct Fe, Ca, Si, Al, and O, respectively. Increasing Al2O3 concentration in the starting sinter mixture increased the temperature range over which SFCA-I was stable before the formation of SFCA, and it stabilized SFCA to a higher temperature before it melted to form a Fe3O4 + melt phase assemblage (1486 K to 1581 K [1213 °C to 1308 °C]). During cooling, the first phase to crystallize from the melt (1452 K to 1561 K [1179 °C to 1288 °C]) was an Fe-rich phase, similar in composition to SFCA-I, and it had an average composition 58.88, 6.89, 0.82, 3.00, and 31.68 wt pct Fe, Ca, Si, Al, and O, respectively. At lower temperatures (1418 K to 1543 K [1145 °C to 1270 °C]), this phase reacted with melt to form SFCA. Increasing Al2O3 increased the temperature at which crystallization of the Fe-rich phase occurred, increased the temperature at which crystallization of SFCA occurred, and suppressed the formation of Fe2O3 (1358 K to 1418 K [1085 °C to 1145 °C]) to lower temperatures.

  7. 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.

  8. The effect of initiation feature and environment on fatigue crack formation and early propagation in aluminum zinc magnesium copper

    NASA Astrophysics Data System (ADS)

    Burns, James T.

    The current research provides insight into fatigue crack formation and progression in the poorly understood size regime that bridges safe-life and damage tolerance approaches; particular attention is given to the influences of corrosion-induced degradation and time-cycle dependent loading environment effects. Quantitative analysis of crack formation life (Ni), microstructurally small crack (<500 microm) propagation kinetics (da/dN), and the effect of cold loading environment provide the means to validate mechanism-based modeling. Both pristine and corroded (L-S surface) 7075-T651 specimens were fatigued at 23°C, -50°C and -90°C under various applied stresses. Microscopy of programmed loading-induced crack surface marks produced an unparalleled Ni and small crack da/dN database. Results show that fatigue crack formation involves a complex interaction of elastic stress concentration, due to a 3-dimensional macro-pit, coupled with local micro-feature (and constituent) induced plastic strain concentration. Such interactions cause high Ni variability, but, from an engineering perspective, a broadly corroded surface should contain an extreme group of features driving Ni to ˜0. At low-applied stresses, Ni consumes a significant portion of total life, which is well predicted by coupling elastic-plastic FEA with empirical low-cycle fatigue life models. All pristine and corroded da/dN were uniquely correlated using complex continuum stress intensity (K) and crack opening solutions which account for the stress concentrating formation feature. Multiple crack growth regimes were observed, typical of environment enhanced fatigue in Al alloys. Such behavior is not captured by prominent mechanics-based small crack models. Furthermore, neither local closure nor slip-based models captured the order of magnitude variability in da/dN attributed to microstructure. Low temperature loading produces an order of magnitude increase in Ni, and even larger reduction in da/dN, due to

  9. The effects of synthesis pH and hydrothermal treatment on the formation of zinc aluminum hydrotalcites

    SciTech Connect

    Kloprogge, J. Theo . E-mail: t.kloprogge@qut.edu.au; Hickey, Leisel; Frost, Ray L.

    2004-11-01

    Zn/Al hydrotalcites were synthesized by coprecipitation at increasing pH from 6.0 to 14.0, followed by hydrothermal treatment at 150 deg. C for 7 days. The materials were characterized by X-ray diffraction (XRD), STEM, inductively coupled plasma-atomic emission spectroscopy (ICP-AES), thermal analysis, infrared spectroscopy and Raman spectroscopy. The XRD analysis for the samples prepared between pH 9.0 and 12.0 showed a pattern typical of hydrotalcite, with a c-axis distance of {approx}22.6A. STEM showed that the pH of preparation affected the stability of the hydrotalcite and that instability, observed at pH 9.0, favored the formation of mixed phases when treated hydrothermally. It was also shown that treatment of a stable starting material increased the crystallinity and resulted in the formation of hexagonal plate-shaped particles. ICP-AES and thermal analysis showed that the Zn/Al ratio and thermal stability increased with pH. Thermal analysis showed three major weight losses corresponding to the loss of interparticle water, interlayer water and dehydroxylation of the hydroxide layers and decarbonization of the interlayer region.

  10. Formation of ordered films of axially bridged aluminum phthalocyanine [(tBu)4PcAl]2O via magnetic field-induced reaction.

    PubMed

    Basova, Tamara; Berezin, Aleksei; Nadolinny, Vladimir; Peisert, Heiko; Chassé, Thomas; Banimuslem, Hikmat; Hassan, Aseel

    2013-11-28

    The μ-(oxo)bis[tetra-tert-butylphthalocyaninato] aluminum(III) [(tBu)4PcAl]2O films with the crystallites oriented preferably in one direction were obtained via chemical transformation of tetra-tert-butylsubstituted chloroaluminum(III) phthalocyanine (tBu)4PcAlCl film upon its annealing in magnetic field. A comparative analysis of the influence of post-deposition annealing process without and under applied magnetic field of 1 T, on the orientation and morphology of (tBu)4PcAlCl and [(tBu)4PcAl]2O films, has been carried out by the methods of UV-vis, Infrared and Raman spectroscopies, XRD as well as atomic force microscopy. The formation of [(tBu)4PcAl]2O films with elongated crystallites having preferential orientation was observed upon heating of the films in magnetic field while annealing without magnetic field under the same conditions does not demonstrate any effect on the structure and morphology of these films. The reasons of the sensitivity of this reaction to the presence of such magnetic field is discussed and studied by electronic paramagnetic resonance spectroscopy. PMID:24289372

  11. Effects of Substrate Roughness on Splat Formation for Ni-Cr Particles Plasma Sprayed onto Aluminum Substrates

    NASA Astrophysics Data System (ADS)

    Brossard, S.; Munroe, P. R.; Tran, A. T. T.; Hyland, M. M.

    2010-09-01

    Roughening of the substrate, for instance by grit-blasting or etching, is often used before plasma spraying in order to provide a high degree of roughness that promotes mechanical interlocking of the sprayed coating and consequently improved adhesion. This study investigates the morphology and microstructure of NiCr splats formed on such rough Al substrates, where roughness was generated by a number of methods including grinding and etching. Cross sections of the splats and the splat-substrate interface were examined using a range of electron microscopy techniques. Localized substrate melting and chemical mixing with the splat material was observed, forming very particular structures. The formation of various oxides phases and voids was also noted and found to increase, along with the degree of the substrate melting, with increasing substrate roughness. The structures observed were related to the spray conditions and substrate morphology.

  12. A CRITICAL EXAMINATION OF THE X-WIND MODEL FOR CHONDRULE AND CALCIUM-RICH, ALUMINUM-RICH INCLUSION FORMATION AND RADIONUCLIDE PRODUCTION

    SciTech Connect

    Desch, S. J.; Morris, M. A.; Connolly, H. C.; Boss, Alan P.

    2010-12-10

    Meteoritic data, especially regarding chondrules and calcium-rich, aluminum-rich inclusions (CAIs), and isotopic evidence for short-lived radionuclides (SLRs) in the solar nebula, potentially can constrain how planetary systems form. Interpretation of these data demands an astrophysical model, and the 'X-wind' model of Shu et al. and collaborators has been advanced to explain the origin of chondrules, CAIs, and SLRs. It posits that chondrules and CAIs were thermally processed <0.1 AU from the protostar, then flung by a magnetocentrifugal outflow to the 2-3 AU region to be incorporated into chondrites. Here we critically examine key assumptions and predictions of the X-wind model. We find a number of internal inconsistencies: theory and observation show no solid material exists at 0.1 AU; particles at 0.1 AU cannot escape being accreted into the star; particles at 0.1 AU will collide at speeds high enough to destroy them; thermal sputtering will prevent growth of particles; and launching of particles in magnetocentrifugal outflows is not modeled, and may not be possible. We also identify a number of incorrect predictions of the X-wind model: the oxygen fugacity where CAIs form is orders of magnitude too oxidizing, chondrule cooling rates are orders of magnitude lower than those experienced by barred olivine chondrules, chondrule-matrix complementarity is not predicted, and the SLRs are not produced in their observed proportions. We conclude that the X-wind model is not relevant to chondrule and CAI formation and SLR production. We discuss more plausible models for chondrule and CAI formation and SLR production.

  13. Refractory Boride Formation and Microstructure Evolution during Solidification of Titanium-Boron and Titanium Aluminum-Boron Alloys

    NASA Astrophysics Data System (ADS)

    Hyman, Mark Edward

    1990-01-01

    gamma-TiAl alloys targeted for use as a structural material in advanced aerospace applications lack adequate creep strength at high temperatures. Incorporation of hard refractory second phase particles (e.g. TiB _2) exhibiting large aspect ratios (i.e. needles) can increase creep strength by constraining the plastic flow of the matrix during high temperature service. Matrix microstructure evolution and refractory boride formation in binary Ti-B and Ti-(25-52) at% Al and <= ~ 6 at% B alloys during conventional solidification is examined. The effects of rapid solidification processing (RSP) on microstructure evolution and boride morphology in ternary alloys is examined in electromagnetically levitated droplets processed via gas and splat quenching. A liquidus projection near the Ti-Al edge binary is deduced from a combination of computer modelling efforts and experimental evidence. The primary fields of crystallization sequentially traversed with increasing Al content starting from the Ti-B edge binary are: TiB to Ti_3B_4 to TiB_2 and beta to alpha to gamma for B-rich (i.e. ~5 at% B) and dilute alloys, respectively. A monovariant line of the type, L to M + TiB_2 (where M = beta, alpha , and gamma) was found to run slightly below the ~1 at% B isoconcentration line near the equiatomic TiAl composition. Matrix microstructure evolution and boride formation in these ternary alloys can be explained using the proposed liquidus projection for the Ti-Al-B system. TiB_2 forms in Ti-Al-B alloys (i.e. >= 35 at% Al) with various morphologies--blocky, plate/needle and flakes--and are extensively characterized by TEM and SEM. Their growth mechanisms leading to their various morphologies is discussed. Aside from the boride phases formed, the solidification microstructures of the Ti-Al -B alloys of interest showed essentially the same constituent phases as those of binary Ti-Al alloys of similar composition. Characterization of supercooled ternary droplets dilute in B (i.e. <=1 at% B

  14. 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

  15. Interaction of aluminum projectiles with quartz sand in impact experiments: Formation of khatyrkite (CuAl2) and reduction of SiO2 to Si

    NASA Astrophysics Data System (ADS)

    Hamann, Christopher; Stöffler, Dieter; Reimold, Wolf Uwe

    2016-11-01

    We analyzed the interaction of spherical, 6.36-mm-diameter, Cu-bearing aluminum projectiles with quartz sand targets in hypervelocity impact experiments performed at NASA Ames Vertical Gun Range. Impact velocities and inferred peak shock pressures varied between 5.9 and 6.5 km/s and ∼41 and 48 GPa, respectively. Shocked particles ("impact melt particles") coated with thin crusts of molten projectile material were recovered from the floors of the ca. 33-cm-diameter craters and the respective ejecta blankets. Through petrographic and chemical (optical microscopy, FE-EMPA, SEM-EDX, and XRF) analysis we show that these particles have a layered structure manifested in distinct layers of decreasing shock metamorphism. These can be characterized by the following physical and chemical reactions and alteration products: (i) complete melting and subsequent recrystallization of the projectile, forming a distinct crystallization texture in the fused metal crust; (ii) projectile-target mixing, involving a redox reaction between Cu-bearing Al alloy und SiO2, leading to formation of khatyrkite (CuAl2), Al2O3 melt, euhedral silicon crystals, and spherical droplets of silicon; (iii) melting of quartz to lechatelierite and formation of planar deformation features in relic quartz grains; and (iv) shock lithification of quartz grains with fracturing of grains, grain-boundary melting, planar deformation features, and complete loss of porosity. To our knowledge, this is the first report of khatyrkite formed experimentally in hypervelocity impact experiments. These results have implications for the understanding of a similar redox reaction between Al-Cu metal and siliceous impact melt recently postulated for the Khatyrka CV3 carbonaceous chondrite. Moreover, these results bear on the processes that lead to layers of regolith on the surfaces of planetary bodies without atmospheres, such as asteroids in the main belt (e.g., 4 Vesta), and on the Moon. Specifically, impacts of mm

  16. Electron Diffraction Evidence for the Ordering of Excess Nickel Atoms by Relation to Stoichiometry in Nickel-Rich Beta'-Nial Formation of a Nickel-Aluminum (Ni2al) Superlattices

    NASA Technical Reports Server (NTRS)

    Reynaud, F.

    1988-01-01

    In electron diffraction patterns of nickel-rich beta-NiAl alloys, many anomalies are observed. One of these is the appearance of diffuse intensity maxima between the reflexions of the B2 structure. This is explained by the short-range ordering of the excess nickel atoms on the simple cubic sublattice occupied only by aluminum atoms in the stoichiometric, perfectly ordered NiAl alloy. After annealing Ni 37.5 atomic percent Al and Ni 37.75 atomic percent Al for 1 week at 300 and 400 C, the diffuse intensity maxima transformed into sharp superstructure reflexions. These reflexions are explained by the formation of the four possible variants of an ordered hexagonal superstructure corresponding to the Ni2Al composition. This structure is closely related to the Ni2Al3 structure (same space group) formed by the ordering of vacancies on the nickel sublattice in aluminum-rich beta-NiAl alloys.

  17. Gelling nature of aluminum soaps in oils.

    PubMed

    Wang, Xiaorong; Rackaitis, Mindaugas

    2009-03-15

    Aluminum soaps are notable for their ability to form soap-hydrocarbon gels of high viscosity. For more than half a century, it has been believed that the gelling mechanism is due to a formation of polymeric chains of aluminum molecules with the aluminum atoms linking along the axis and with the fatty acid chain extended sideways. Here we report results from an investigation using high-resolution electron microscopy and rheology measurements that clearly resolve the ambiguity. Our results reveal that the gelling mechanism stems from the formation of spherical nano-sized micelles from aluminum soap molecules, and those colloidal micelle particles then aggregate into networks of highly fractal and jammed structures. The earlier proposed polymer chain-like structure is definitely incorrect. The discovery of aluminum soap particles could expand application of these materials to new technologies.

  18. Specific features of aluminum nanoparticle water and wet air oxidation

    SciTech Connect

    Lozhkomoev, Aleksandr S. Glazkova, Elena A. Svarovskaya, Natalia V. Bakina, Olga V. Kazantsev, Sergey O. Lerner, Marat I.

    2015-10-27

    The oxidation processes of the electrically exploded aluminum nanopowders in water and in wet air are examined in the paper. The morphology of the intermediate reaction products of aluminum oxidation has been studied using the transmission electron microscopy. It was shown that the aluminum nanopowder water oxidation causes the formation of the hollow spheres with mesoporous boehmite nanosheets coating. The wedge-like bayerite particles are formed during aluminum nanopowder wet air oxidation.

  19. Specific features of aluminum nanoparticle water and wet air oxidation

    NASA Astrophysics Data System (ADS)

    Lozhkomoev, Aleksandr S.; Glazkova, Elena A.; Svarovskaya, Natalia V.; Bakina, Olga V.; Kazantsev, Sergey O.; Lerner, Marat I.

    2015-10-01

    The oxidation processes of the electrically exploded aluminum nanopowders in water and in wet air are examined in the paper. The morphology of the intermediate reaction products of aluminum oxidation has been studied using the transmission electron microscopy. It was shown that the aluminum nanopowder water oxidation causes the formation of the hollow spheres with mesoporous boehmite nanosheets coating. The wedge-like bayerite particles are formed during aluminum nanopowder wet air oxidation.

  20. Conference Rules, Part 1

    ERIC Educational Resources Information Center

    Kerber, Linda K.

    2008-01-01

    Most academic conferences are preceded by some effort to make the sessions different from the usual format, but the usual format overwhelmingly prevails. That is: Each panel discussion runs no longer than two hours, during which two, three, or four specialists stand at a lectern and talk. Sometimes they will read a prepared paper; sometimes they…

  1. A Pseudomonas strain isolated from date-palm rhizospheres improves root growth and promotes root formation in maize exposed to salt and aluminum stress.

    PubMed

    Zerrouk, Izzeddine Zakarya; Benchabane, Messaoud; Khelifi, Lakhdar; Yokawa, Ken; Ludwig-Müller, Jutta; Baluska, Frantisek

    2016-02-01

    The aim of this study was to evaluate the effectiveness of Pseudomonas fluorescens 002 (P.f.002.), isolated from the rhizosphere of date palms from the Ghardaia region in the Algerian Sahara, to promote root growth of two varieties of maize under conditions of salt and aluminum stress. Primary roots of 5-day-old seedlings were inoculated with P.f.002., and seedlings were then grown under both control and stressed conditions. Primary, lateral, and seminal root lengths and numbers, as well as root dry mass, were evaluated. P.f.002 increased all parameters measured under both salt and aluminum stress. Hence, the use of P.f.002 may represent an important biotechnological approach to decrease the impact of salinity and acidity in crops. PMID:26759938

  2. Beta4 integrin-dependent formation of polarized three-dimensionalarchitecture confers resistance to apoptosis in normal and malignantmammary epithelium

    SciTech Connect

    Weaver, Valerie M.; Lelievre, Sophie; Lakins, Johnathon N.; Chrenek, Micah A.; Jones, Jonathan C.R.; Giancotti, Filippo; Werb, Zena; Bissell, Mina J.

    2002-08-27

    Tumor cells can evade chemotherapy by acquiring resistanceto apoptosis. We investigated the molecular mechanism whereby malignantand nonmalignant mammary epithelial cells become insensitive toapoptosis. We show that regardless of growth status formation ofpolarized, three-dimensional structures driven by basement membraneconfers protection to apoptosis in both nonmalignant and malignantmammary epithelial cells. By contrast, irrespective of their malignantstatus, nonpolarized structures are sensitive to induction of apoptosis.Resistance to apoptosis requires ligation of beta4 integrins, whichregulates tissue polarity, hemidesmosome formation and NFkB activation.Expression of beta4 integrin that lacks the hemidesmosome targetingdomain interferes with tissue polarity and NFkB activation and permitsapoptosis. These results indicate that integrin-induced polarity maydrive tumor cell resistance to apoptosis-inducing agents via effects onNFkB.

  3. Occupational exposure to aluminum and its biomonitoring in perspective.

    PubMed

    Riihimäki, Vesa; Aitio, Antero

    2012-11-01

    Exposure to aluminum at work is widespread, and people are exposed to several species of aluminum, which differ markedly as to the kinetics and toxicity. Especially welding of aluminum is widely applied and continuously expanding. Inhalation of fine particles of sparsely soluble aluminum results in the retention of deposited particles in the lungs. From the lungs, aluminum is released to the blood and distributed to bones and the brain, and excreted to urine. Soluble aluminum compounds are not accumulated in the lungs. Neurotoxicity is the critical effect of exposure to sparsely soluble aluminum compounds. Studies on workers exposed to aluminum welding fumes have revealed disturbances of cognitive processes, memory and concentration, and changes in mood and EEG. Early pulmonary effects have been observed among aluminum powder-production workers using high-resolution computed tomography. The primary objective of aluminum biomonitoring (BM) is to help prevent the formation of aluminum burden in the lungs and thereby to prevent harmful accumulation of aluminum in target organs. BM of aluminum can be effectively used for this purpose in the production/use of aluminum powders, aluminum welding, as well as plasma cutting, grinding, polishing and thermal spraying of aluminum. BM of aluminum may also be similarly useful in the smelting of aluminum and probably in the production of corundum. BM can help identify exposed individuals and roughly quantitate transient exposure but cannot predict health effects in the production/use of soluble aluminum salts. For urinary aluminum (U-Al) we propose an action limit of 3 µmol/L, corrected to a relative density of 1.021, in a sample collected preshift after two days without occupational exposure, and without use of aluminum-containing drugs. This value corresponds roughly to 2.3 µmol/g creatinine. Compliance with this limit is expected to protect the worker against the critical effect of aluminum in exposure to sparsely soluble

  4. Recovery of aluminum alum from waste anode-oxidizing solution

    SciTech Connect

    Lin, S.H.; Lo, M.C.

    1998-12-31

    Recovery of aluminum alum (aluminum ammonium sulfate) by crystallization from waste anode-oxidizing solution in the aluminum surface finishing industry was investigated in this study. Effects of various operating conditions including the mole ratio of ammonium hydroxide and aluminum ion, temperature and seed alum dosage on the aluminum alum formation, acid recovery and aluminum ion removal were examined. Both one- and two-step processes of crystallization were employed in synthesizing the aluminum alum and in the meantime in reducing the aluminum ion concentration in the waste anode-oxidizing solution. Based on the test results, optimum operating conditions were recommended for efficient operation of the crystallization process. The residual acid solution after crystallization was found suitable for reuse in the anode-oxidizing process.

  5. Paternal and maternal genomes confer opposite effects on proliferation, cell-cycle length, senescence, and tumor formation.

    PubMed

    Hernandez, Lidia; Kozlov, Serguei; Piras, Graziella; Stewart, Colin L

    2003-11-11

    Loss of imprinting is the silencing of active imprinted genes or the activation of silent imprinted genes, and it is one of the most common epigenetic changes associated with the development of a wide variety of tumors. Here, we have analyzed the effects that global imprinted gene expression has on cell proliferation and transformation. Primary mouse embryonic fibroblasts (MEFs), whose entire genome is either exclusively paternal (androgenetic) or maternal (parthenogenetic), exhibit dramatically contrasting patterns of growth. In comparison with biparental MEFs, andro-genetic proliferation is characterized by a shorter cell cycle, increased saturation density, spontaneous transformation, and formation of tumors at low passage number. Parthenogenetic MEFs reach a lower saturation density, senesce, and die. The maternally expressed imprinted genes p57kip2 and M6P/Igf2r retard proliferation and reduce the long-term growth of MEFs. In contrast, the paternally expressed growth factor Igf2 is essential for the long-term proliferation of all genotypes. Increased Igf2 expression in primary MEFs not only stimulates proliferation, but also results in their rapid conversion to malignancy with tumor formation of short latency. Our results reveal that paternally expressed imprinted genes, in the absence of maternal imprinted genes, predispose fibroblasts to rapid transformation. A potent factor in their transformation is IGF2, which on increased expression results in the rapid conversion of primary cells to malignancy. These results reveal a route by which malignant choriocarcinoma may arise from molar pregnancies. They also suggest that the derivation of stem cells from parthenogenetic embryos, for the purposes of therapeutic cloning, may be ineffective. PMID:14581617

  6. Constraints on formation processes of two coarse-grained calcium- aluminum-rich inclusions: a study of mantles, islands and cores

    USGS Publications Warehouse

    Meeker, G.P.

    1995-01-01

    Many coarse-grained calcium- aluminum-rich inclusions (CAIs) contain features that are inconsistent with equilibrium liquid crystallization models of origin. Spinel-free islands (SFIs) in spinel-rich cores of Type B CAIs are examples of such features. One model previously proposed for the origin of Allende 5241, a Type B1 CAI containing SFIs, involves the capture and assimilation of xenoliths by a liquid droplet in the solar nebula (El Goresy et al, 1985; MacPherson et al 1989). This study reports new textural and chemical zoning data from 5241 and identifies previously unrecognized chemical zoning patterns in the melilite mantle and in a SFI. -from Author

  7. Aluminum-based metal-air batteries

    DOEpatents

    Friesen, Cody A.; Martinez, Jose Antonio Bautista

    2016-01-12

    Provided in one embodiment is an electrochemical cell, comprising: (i) a plurality of electrodes, comprising a fuel electrode that comprises aluminum and an air electrode that absorbs gaseous oxygen, the electrodes being operable in a discharge mode wherein the aluminum is oxidized at the fuel electrode and oxygen is reduced at the air electrode, and (ii) an ionically conductive medium, comprising an organic solvent; wherein during non-use of the cell, the organic solvent promotes formation of a protective interface between the aluminum of the fuel electrode and the ionically conductive medium, and wherein at an onset of the discharge mode, at least some of the protective interface is removed from the aluminum to thereafter permit oxidation of the aluminum during the discharge mode.

  8. Nanostructured lithium-aluminum alloy electrodes for lithium-ion batteries.

    SciTech Connect

    Hudak, Nicholas S.; Huber, Dale L.

    2010-12-01

    Electrodeposited aluminum films and template-synthesized aluminum nanorods are examined as negative electrodes for lithium-ion batteries. The lithium-aluminum alloying reaction is observed electrochemically with cyclic voltammetry and galvanostatic cycling in lithium half-cells. The electrodeposition reaction is shown to have high faradaic efficiency, and electrodeposited aluminum films reach theoretical capacity for the formation of LiAl (1 Ah/g). The performance of electrodeposited aluminum films is dependent on film thickness, with thicker films exhibiting better cycling behavior. The same trend is shown for electron-beam deposited aluminum films, suggesting that aluminum film thickness is the major determinant in electrochemical performance regardless of deposition technique. Synthesis of aluminum nanorod arrays on stainless steel substrates is demonstrated using electrodeposition into anodic aluminum oxide templates followed by template dissolution. Unlike nanostructures of other lithium-alloying materials, the electrochemical performance of these aluminum nanorod arrays is worse than that of bulk aluminum.

  9. Formation of biphenyl and dibenzofuran phytoalexins in the transition zones of fire blight-infected stems of Malus domestica cv. 'Holsteiner Cox' and Pyrus communis cv. 'Conference'.

    PubMed

    Chizzali, Cornelia; Khalil, Mohammed N A; Beuerle, Till; Schuehly, Wolfgang; Richter, Klaus; Flachowsky, Henryk; Peil, Andreas; Hanke, Magda-Viola; Liu, Benye; Beerhues, Ludger

    2012-05-01

    In the rosaceous subtribe Pyrinae (formerly subfamily Maloideae), pathogen attack leads to formation of biphenyls and dibenzofurans. Accumulation of these phytoalexins was studied in greenhouse-grown grafted shoots of Malus domestica cv. 'Holsteiner Cox' and Pyrus communis cv. 'Conference' after inoculation with the fire blight bacterium, Erwinia amylovora. No phytoalexins were found in leaves. However, both classes of defence compounds were detected in the transition zone of stems. The flanking stem segments above and below this zone, which were necrotic and healthy, respectively, were devoid of detectable phytoalexins. The transition zone of apple stems contained the biphenyls 3-hydroxy-5-methoxyaucuparin, aucuparin, noraucuparin and 2'-hydroxyaucuparin and the dibenzofurans eriobofuran and noreriobofuran. In pear, aucuparin, 2'-hydroxyaucuparin, noreriobofuran and in addition 3,4,5-trimethoxybiphenyl were detected. The total phytoalexin content in the transition zone of pear was 25 times lower than that in apple. Leaves and stems of mock-inoculated apple and pear shoots lacked phytoalexins. A number of biphenyls and dibenzofurans were tested for their in vitro antibacterial activity against some Erwinia amylovora strains. The most efficient compound was 3,5-dihydroxybiphenyl (MIC=115 μg/ml), the immediate product of biphenyl synthase which initiates phytoalexin biosynthesis.

  10. The Cleaning of Aluminum Frame Assembly Units

    SciTech Connect

    Shen, T H

    2001-05-16

    The Brulin immersion and the precision cleaning experiments have shown that neither the Brulin solution nor the precision cleaning in AstroPak causes the smut formation on aluminum surfaces. The acid-bath cleaning in GTC is the primary source of the smut formation. The current GTC acid formulation etches the aluminum matrix quite aggressively, but does not appear to appreciably attack the Si particles. Therefore, this acid-bath cleaning will leave the cast-aluminum part surfaces with many protruded Si particles, which could potentially cause smut problems in the cleaning process down-stream. To ensure the removal of all loose Si particles from the cast-aluminum parts, it is necessary to physically hand-wipe and vigorously wash the acid-bath cleaned surfaces. Furthermore, the casting porosity in alloy A356 could be another source in causing high swipe readings in the FAU parts.

  11. Aluminum, copper, iron and zinc differentially alter amyloid-Aβ(1-42) aggregation and toxicity.

    PubMed

    Bolognin, Silvia; Messori, Luigi; Drago, Denise; Gabbiani, Chiara; Cendron, Laura; Zatta, Paolo

    2011-06-01

    Amyloid-β(1-42) (Aβ) is believed to play a crucial role in the ethiopathogenesis of Alzheimer's Disease (AD). In particular, its interactions with biologically relevant metal ions may lead to the formation of highly neurotoxic complexes. Here we describe the species that are formed upon reacting Aβ with several biometals, namely copper, zinc, iron, and with non-physiological aluminum to assess whether different metal ions are able to differently drive Aβ aggregation. The nature of the resulting Aβ-metal complexes and of the respective aggregates was ascertained through a number of biophysical techniques, including electrospray ionization mass spectrometry, dynamic light scattering, fluorescence, transmission electron microscopy and by the use of conformation-sensitive antibodies (OC, αAPF). Metal binding to Aβ is shown to confer highly different chemical properties to the resulting complexes; accordingly, their overall aggregation behaviour was deeply modified. Both aluminum(III) and iron(III) ions were found to induce peculiar aggregation properties, ultimately leading to the formation of annular protofibrils and of fibrillar oligomers. Notably, only Aβ-aluminum was characterized by the presence of a relevant percentage of aggregates with a mean radius slightly smaller than 30 nm. In contrast, both zinc(II) and copper(II) ions completely prevented the formation of soluble fibrillary aggregates. The biological effects of the various Aβ-metal complexes were studied in neuroblastoma cell cultures: Aβ-aluminum turned out to be the only species capable of triggering amyloid precursor and tau181 protein overproduction. Our results point out that Al can effectively interact with Aβ, forming "structured" aggregates with peculiar biophysical properties which are associated with a high neurotoxicity.

  12. Conference Connections: Rewiring the Circuit

    ERIC Educational Resources Information Center

    Siemens, George; Tittenberger, Peter; Anderson, Terry

    2008-01-01

    Increased openness, two-way dialogue, and blurred distinctions between experts and amateurs have combined with numerous technology tools for dialogue, personal expression, networking, and community formation to "remake" conferences, influencing not only how attendees participate in but also how organizers host conferences today. (Contains 31…

  13. Nanoscale surface modifications and formation of conical structures at aluminum surface induced by single shot exposure of soft x-ray laser pulse

    SciTech Connect

    Ishino, Masahiko; Tanaka, Momoko; Hasegawa, Noboru; Nishikino, Masaharu; Ohba, Toshiyuki; Kaihori, Takeshi; Ochi, Yoshihiro; Imazono, Takashi; Kawachi, Tetsuya; Faenov, Anatoly Ya.; Pikuz, Tatiana A.; Tamotsu, Satoshi; Inogamov, Nail A.; Khohlov, Viktor A.; Zhakhovsky, Vasily V.; Skobelev, Igor Yu.; Fortov, Vladimir E.; Shepelev, Vadim V.

    2011-01-01

    We irradiated the soft x-ray laser (SXRL) pulses having a wavelength of 13.9 nm, a duration time of 7 ps, and fluences of up to 27 mJ/cm{sup 2} to aluminum (Al) surface. After the irradiation process, the modified surface was observed with the visible microscope, the scanning electron microscope, and the atomic force microscope. The surface modifications caused by the SXRL pulses were clearly seen, and it was found that the conical structures having about 70-150 nm in diameters were formed under a single pulse shot. The conical structures were formed in the features with the average depth of about 40 nm, and this value was in accordance with the attenuation length of the SXRL beam for Al. However, those conical structures were deconstructed under the multiple pulse shots exposure. Thermomechanical modeling of SXRL laser interaction with Al surface, which explains nanostructure surface modification, was provided.

  14. Novel routes to metalloorganics containing aluminum from minerals

    NASA Astrophysics Data System (ADS)

    Narayanan, Ramasubramanian

    Novel pathways for synthesizing Al metalloorganics directly from widely available oxides and oxo-hydroxides of aluminum are developed. The Al metalloorganics are then used to produce low-cost precursors for ceramics and polymers containing Al. Alumatrane, an unique, air-stable, aluminum alkoxide is prepared in one step from aluminum hydroxide in quantitative yields. Subsequently, alumatrane was used to prepare and characterize all group II dialuminate ceramics (MAlsb2Osb4, M = Mg, Ca, Sr, Ba). Similarly, an air-stable alkoxide of silicon was synthesized directly from SiOsb2, and is used in conjunction with alumatrane to produce precursors for aluminosilicate ceramics (MAlSiOsb4, M = K, Li, Na). Aluminum formate is synthesized, in differing efficiencies, from different crystalline minerals of Al, by direct dissolution in formic acid. A few other aluminum carboxylates are also synthesized, either directly from minerals or from aluminum formates, thus expanding the scope of the acid dissolution of aluminum hydroxides. Aluminum allyloxypropanoate (AAP) (Al(Osb2CCHsb2CHsb2OCH{=}CHsb2)sb2(OH)), an aluminum carboxylate with a polymerizable group has been synthesized from aluminum formate. This, has been incorporated into methyl methacrylate (MMA) polymers to impart fire retardancy. The increase in char yields as a result of AAP incorporation, indicate improved fire retardancy. Fire retardant characteristics of alumatrane has also been investigated, in MMA polymers and in a polyurethane polymer, taking char yields as a measure of fire retardance efficiency.

  15. 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)

  16. Conference summary

    NASA Astrophysics Data System (ADS)

    Rebolo, R.

    ``Brown dwarfs come of age" was a stimulating conference attended by a large number of very active researchers, including many young students and post-docs who were largely responsible for the lively atmosphere that we enjoyed during the full meeting. Major theoretical and observational challenges currently faced in the study of brown dwarfs were reviewed. Key spectroscopic work is being conducted to determine atmospheric temperatures, surface gravities and metallicities, essential to understand the evolution of substellar objects. Research on ultracool atmospheres is extended down to temperatures typical of the atmosphere of the Earth. Characterisation of brown dwarfs at all wavelengths from X-ray to radio is ongoing and investigation of time domain phenomena reveal interesting new processes in cool atmospheres. In addition to talks on these topics, a large number of presentations addressed the formation and evolution of brown dwarfs, the lower end of the Initial Mass Function, the properties of substellar binaries, the angular momentum and disk evolution in very low-mass systems, results of large scale surveys aimed to find the lowest luminosity and coolest brown dwarfs, searches in star clusters delineating the evolution with age of the properties of brown dwarfs, binary searches and subsequent follow-up work enabling dynamical mass determinations. The excellent level of the review talks, oral and poster presentations and the work of the enthusiastic researchers that attended the meeting ensure a brilliant future for substellar research 18 years after the discovery of the first brown dwarfs.

  17. 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.

  18. 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.

  19. Making Conferences Human Places of Learning

    ERIC Educational Resources Information Center

    Kenny, Michael

    2014-01-01

    Open Space Technology is a cumbersome name for a participative conference model that enables dynamic inclusive engagement and challenges traditional, highly structured hierarchical conference formats. Based on self-organising systems, (Wenger, 1998) Open Space Technology conferences have an open process, start with no agenda and empower the most…

  20. The anisotropy of aluminum and aluminum alloys

    NASA Astrophysics Data System (ADS)

    Hosford, William F.

    2006-05-01

    The anisotropy of textured aluminum is approximated by a yield criterion with an exponent of eight. The use of this criterion in metal-forming analyses has improved the understanding of the formability of aluminum and other metals. The effect of anisotropy on the limiting drawing ratio in cupping is less than that expected from the quadratic Hill yield criterion and the effect of texture on forming limit diagrams is negligible. A method of predicting the effect of strain-path changes on forming limit curves of aluminum alloy sheets has proven to agree with experiments.

  1. Superhydrophobic coating deposited directly on aluminum

    NASA Astrophysics Data System (ADS)

    Escobar, Ana M.; Llorca-Isern, Nuria

    2014-06-01

    This study develops an alternative method for enhancing superhydrophobicity on aluminum surfaces with an amphiphilic reagent such as the dodecanoic acid. The goal is to induce superhydrophobicity directly through a simple process on pure (99.9 wt%) commercial aluminum. The initial surface activation leading to the formation of the superhydrophobic coating is studied using confocal microscopy. Superhydrophobic behavior is analyzed by contact angle measurements, scanning electron microscopy (SEM) and atomic force microscopy (AFM). The highest contact angle (approaching 153°) was obtained after forming hierarchical structures with a particular roughness obtained by grinding and polishing microgrooves on the aluminum surface together with the simultaneous action of HCl and dodecanoic acid. The results also showed that after immersion in the ethanol-acidic-fatty acid solutions, they reacted chemically through the action of the fatty acid, on the aluminum surface. The mechanism is analyzed by TOF-SIMS and XPS in order to determine the molecules involved in the reaction. The TOF-SIMS analysis revealed that the metal and its oxides seem to be necessary, and that free-aluminum is anchored to the fatty acid molecules and to the alumina molecules present in the medium. Consequently, both metallic aluminum and aluminum oxides are necessary in order to form the compound responsible for superhydrophobicity.

  2. 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.

  3. Fabrication of aluminum based nanomaterials

    NASA Astrophysics Data System (ADS)

    Poirier, Dominique

    2009-11-01

    Structural applications in transportation necessitate materials with high specific strength and stiffness. With its low density, aluminum (Al) is an interesting candidate, but further strengthening would be beneficial. In this work, the benefits and limitations of nanoreinforcements for aluminum strengthening has been assessed through the addition of carbon nanotube (CNTs) and nanometric alumina (n-Al2O3) to an aluminum matrix by powder metallurgy. It has been found that mechanical milling can homogeneously disperse n-Al2O3 in aluminum. Furthermore, mechanical milling offers the advantages of strengthening the aluminum powder through grain refinement, cold working, solid solution and precipitation. However, CNTs are damaged by mechanical milling, and their homogeneous dispersion cannot be achieved with a chemical dispersant. Nanocomposite consolidation has presented several challenges as hot pressing resulted in a lack of bonding, grain growth and the formation of Al4C3 from damaged CNTs. Cold spraying of Al2O3/Al has resulted in a porous coating with decreased hardness. The microhardness and compression properties of an Al2O 3/Al nanocomposite produced by mechanical milling followed by hot pressing were measured. Comparison with modeled values and literature results indicates that higher experimental yield strength obtained with the addition of n-Al 2O3 versus micron size Al2O3 is due to in-situ matrix strengthening. Modeling shows that CNTs offer high potential gains in stiffness due to their high aspect ratio and their high Young modulus. On the other hand, as yield gains associated with the addition of nanoreinforcement are mainly due to matrix strengthening, discontinuous nanocomposites do not benefit from the CNT's exceptional strength. In this case, n-Al 2O3 would be selected over CNTs as it is cheaper and more easily dispersed.

  4. Closing the loop: an interactive action-research conference format for delivering updated medical information while eliciting Latina patient/family experiences and psychosocial needs post-genetic cancer risk assessment.

    PubMed

    Macdonald, Deborah J; Deri, Julia; Ricker, Charité; Perez, Martin A; Ogaz, Raquel; Feldman, Nancy; Viveros, Lori A; Paz, Benjamin; Weitzel, Jeffrey N; Blazer, Kathleen R

    2012-09-01

    A patient/family-centered conference was conducted at an underserved community hospital to address Latinas' post-genetic cancer risk assessment (GCRA) medical information and psychosocial support needs, and determine the utility of the action research format. Latinas seen for GCRA were recruited to a half-day conference conducted in Spanish. Content was partly determined from follow-up survey feedback. Written surveys, interactive discussions, and Audience Response System (ARS) queries facilitated the participant-healthcare professional action research process. Analyses included descriptive statistics and thematic analysis. The 71 attendees (41 patients and 27 relatives/friends) were primarily non-US born Spanish-speaking females, mean age 43 years. Among patients, 73 % had a breast cancer history; 85 % had BRCA testing (49 % BRCA+). Nearly all (96 %) attendees completed the conference surveys and ARS queries; ≥48 % participated in interactive discussions. Most (95 %) agreed that the format met their personal interests and expectations and provided useful information and resources. Gaps/challenges identified in the GCRA process included pre-consult anxiety, uncertainty about reason for referral and expected outcomes, and psychosocial needs post-GCRA, such as absorbing and disseminating risk information to relatives and concurrently coping with a recent cancer diagnosis. The combined action research and educational conference format was innovative and effective for responding to continued patient information needs and addressing an important data gap about support needs of Latina patients and family members following genetic cancer risk assessment. Findings informed GCRA process improvements and provide a basis for theory-driven cancer control research. PMID:22678665

  5. Closing the Loop: An interactive action-research conference format for delivering updated medical information while eliciting Latina patient/family experiences and psychosocial needs post-genetic cancer risk assessment

    PubMed Central

    MacDonald, Deborah J.; Deri, Julia; Ricker, Charité; Perez, Martin A.; Ogaz, Raquel; Feldman, Nancy; Viveros, Lori A.; Paz, Benjamin; Weitzel, Jeffrey N.; Blazer, Kathleen R.

    2013-01-01

    Objective A patient/family-centered conference was conducted at an underserved community hospital to address Latinas’ post-genetic cancer risk assessment (GCRA) medical information and psychosocial support needs, and determine the utility of the action research format. Methods Latinas seen for GCRA were recruited to a half-day conference conducted in Spanish. Content was partly determined from follow-up survey feedback. Written surveys, interactive discussions, and Audience Response System (ARS) queries facilitated the participant-healthcare professional action research process. Analyses included descriptive statistics and thematic analysis. Results The 71 attendees (41 patients and 27 relatives/friends) were primarily non-U.S. born Spanish-speaking females, mean age 43 years. Among patients, 73% had a breast cancer history; 85% had BRCA testing (49% BRCA+). Nearly all (96%) attendees completed the conference surveys and ARS queries; ≥48% participated in interactive discussions. Most (95%) agreed that the format met their personal interests and expectations and provided useful information and resources. Gaps/challenges identified in the GCRA process included pre-consult anxiety, uncertainty about reason for referral and expected outcomes, and psychosocial needs post-GCRA, such as absorbing and disseminating risk information to relatives and concurrently coping with a recent cancer diagnosis. Conclusions The combined action research and educational conference format was innovative and effective for responding to continued patient information needs and addressing an important data gap about support needs of Latina patients and family members following genetic cancer risk assessment. Findings informed GCRA process improvements and provide a basis for theory-driven cancer control research. PMID:22678665

  6. Closing the loop: an interactive action-research conference format for delivering updated medical information while eliciting Latina patient/family experiences and psychosocial needs post-genetic cancer risk assessment.

    PubMed

    Macdonald, Deborah J; Deri, Julia; Ricker, Charité; Perez, Martin A; Ogaz, Raquel; Feldman, Nancy; Viveros, Lori A; Paz, Benjamin; Weitzel, Jeffrey N; Blazer, Kathleen R

    2012-09-01

    A patient/family-centered conference was conducted at an underserved community hospital to address Latinas' post-genetic cancer risk assessment (GCRA) medical information and psychosocial support needs, and determine the utility of the action research format. Latinas seen for GCRA were recruited to a half-day conference conducted in Spanish. Content was partly determined from follow-up survey feedback. Written surveys, interactive discussions, and Audience Response System (ARS) queries facilitated the participant-healthcare professional action research process. Analyses included descriptive statistics and thematic analysis. The 71 attendees (41 patients and 27 relatives/friends) were primarily non-US born Spanish-speaking females, mean age 43 years. Among patients, 73 % had a breast cancer history; 85 % had BRCA testing (49 % BRCA+). Nearly all (96 %) attendees completed the conference surveys and ARS queries; ≥48 % participated in interactive discussions. Most (95 %) agreed that the format met their personal interests and expectations and provided useful information and resources. Gaps/challenges identified in the GCRA process included pre-consult anxiety, uncertainty about reason for referral and expected outcomes, and psychosocial needs post-GCRA, such as absorbing and disseminating risk information to relatives and concurrently coping with a recent cancer diagnosis. The combined action research and educational conference format was innovative and effective for responding to continued patient information needs and addressing an important data gap about support needs of Latina patients and family members following genetic cancer risk assessment. Findings informed GCRA process improvements and provide a basis for theory-driven cancer control research.

  7. The viability of aluminum Zintl anion moieties within magnesium-aluminum clusters

    SciTech Connect

    Wang, Haopeng; Jae Ko, Yeon; Zhang, Xinxing; Gantefoer, Gerd; Bowen, Kit H. E-mail: akandalam@wcupa.edu; Schnoeckel, Hansgeorg; Eichhorn, Bryan W.; Jena, Puru; Kiran, Boggavarapu E-mail: akandalam@wcupa.edu; Kandalam, Anil K. E-mail: akandalam@wcupa.edu

    2014-03-28

    Through a synergetic combination of anion photoelectron spectroscopy and density functional theory based calculations, we have investigated the extent to which the aluminum moieties within selected magnesium-aluminum clusters are Zintl anions. Magnesium-aluminum cluster anions were generated in a pulsed arc discharge source. After mass selection, photoelectron spectra of Mg{sub m}Al{sub n}{sup −} (m, n = 1,6; 2,5; 2,12; and 3,11) were measured by a magnetic bottle, electron energy analyzer. Calculations on these four stoichiometries provided geometric structures and full charge analyses for the cluster anions and their neutral cluster counterparts, as well as photodetachment transition energies (stick spectra). Calculations revealed that, unlike the cases of recently reported sodium-aluminum clusters, the formation of aluminum Zintl anion moieties within magnesium-aluminum clusters was limited in most cases by weak charge transfer between the magnesium atoms and their aluminum cluster moieties. Only in cases of high magnesium content, e.g., in Mg{sub 3}Al{sub 11} and Mg{sub 2}Al{sub 12}{sup −}, did the aluminum moieties exhibit Zintl anion-like characteristics.

  8. The formation of tungsten doped Al2O3/ZnO coatings on aluminum by plasma electrolytic oxidation and their application in photocatalysis

    NASA Astrophysics Data System (ADS)

    Stojadinović, Stevan; Vasilić, Rastko; Radić, Nenad; Tadić, Nenad; Stefanov, Plamen; Grbić, Boško

    2016-07-01

    Tungsten doped Al2O3/ZnO coatings are formed by plasma electrolytic oxidation of aluminum substrate in supporting electrolyte (0.1 M boric acid + 0.05 M borax + 2 g/L ZnO) with addition of different concentrations of Na2WO4·2H2O. The morphology, crystal structure, chemical composition, and light absorption characteristics of formed surface coatings are investigated. The X-ray diffraction and X-ray photoelectron spectroscopy results indicate that formed surface coatings consist of alpha and gamma phase of Al2O3, ZnO, metallic tungsten and WO3. Obtained results showed that incorporated tungsten does not have any influence on the absorption spectra of Al2O3/ZnO coatings, which showed invariable band edge at about 385 nm. The photocatalytic activity of undoped and tungsten doped Al2O3/ZnO coatings is estimated by the photodegradation of methyl orange. The photocatalytic activity of tungsten doped Al2O3/ZnO coatings is higher thanof undoped Al2O3/ZnO coatings; the best photocatalytic activity is ascribed to coatings formed in supporting electrolyte with addition of 0.3 g/L Na2WO4·2H2O. Tungsten in Al2O3/ZnO coatings acts as a charge trap, thus reducing the recombination rate of photogenerated electron-hole pairs. The results of PL measurements are in agreement with photocatalytic activity. Declining PL intensity corresponds to increasing photocatalytic activity of the coatings, indicating slower recombination of electron-hole pairs.

  9. 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.

  10. Biomedical Conferences

    NASA Technical Reports Server (NTRS)

    1976-01-01

    As a result of Biomedical Conferences, Vivo Metric Systems Co. has produced cardiac electrodes based on NASA technology. Frequently in science, one highly specialized discipline is unaware of relevant advances made in other areas. In an attempt to familiarize researchers in a variety of disciplines with medical problems and needs, NASA has sponsored conferences that bring together university scientists, practicing physicians and manufacturers of medical instruments.

  11. 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.

  12. 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.

  13. Solute-derived thermal stability of nanocrystalline aluminum and processing factor influence on the formation of Al6Mn quasicrystals in melt-spinning

    NASA Astrophysics Data System (ADS)

    Baker, Andrew H.

    Thermal stability of nanograined metals can be difficult to attain due to the large driving force for grain growth that arises from the significant boundary area constituted by the nanostructure. Kinetic approaches for stabilization of the nanostructure effective at low homologous temperatures often fail at higher homologous temperatures. Thermodynamic approaches for thermal stabilization may offer higher temperature stability. In this research, modest alloying of aluminum with solute (1 at.% Sc, Yb, or Sr) was examined as a means to thermodynamically stabilize a bulk nanostructure at elevated temperatures. After using melt-spinning and ball-milling to create an extended solid-solution and nanostructure with average grain size on the order of 30-45 nm, 1 h annealing treatments at 673 K (0.72 Tm) , 773 K (0.83 Tm) , and 873 K (0.94 Tm) were applied. The alloys remain nanocrystalline (<100 nm) as measured by Warren-Averbach Fourier analysis of x-ray diffraction peaks and direct observation of TEM dark field micrographs, with the efficacy of stabilization: Sr>Yb>Sc. Disappearance of intermetallic phases in the Sr and Yb alloys in the x-ray diffraction spectra are observed to occur coincident with the stabilization after annealing, suggesting that precipitates dissolve and the boundaries are enriched with solute. Melt-spinning has also been shown to be an effective process to produce a class of ordered, but non-periodic crystals called quasicrystals. However, many of the factors related to the creation of the quasicrystals through melt-spinning are not optimized for specific chemistries and alloy systems. In a related but separate aspect of this research, melt-spinning was utilized to create metastable quasicrystalline Al6Mn in an alpha-Al matrix through rapid solidification of Al-8Mn (by mol) and Al-10Mn (by mol) alloys. Wheel speed of the melt-spinning wheel and orifice diameter of the tube reservoir were varied to determine their effect on the resulting volume

  14. 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.

  15. Deposition behavior of residual aluminum in drinking water distribution system: Effect of aluminum speciation.

    PubMed

    Zhang, Yue; Shi, Baoyou; Zhao, Yuanyuan; Yan, Mingquan; Lytle, Darren A; Wang, Dongsheng

    2016-04-01

    Finished drinking water usually contains some residual aluminum. The deposition of residual aluminum in distribution systems and potential release back to the drinking water could significantly influence the water quality at consumer taps. A preliminary analysis of aluminum content in cast iron pipe corrosion scales and loose deposits demonstrated that aluminum deposition on distribution pipe surfaces could be excessive for water treated by aluminum coagulants including polyaluminum chloride (PACl). In this work, the deposition features of different aluminum species in PACl were investigated by simulated coil-pipe test, batch reactor test and quartz crystal microbalance with dissipation monitoring. The deposition amount of non-polymeric aluminum species was the least, and its deposition layer was soft and hydrated, which indicated the possible formation of amorphous Al(OH)3. Al13 had the highest deposition tendency, and the deposition layer was rigid and much less hydrated, which indicated that the deposited aluminum might possess regular structure and self-aggregation of Al13 could be the main deposition mechanism. While for Al30, its deposition was relatively slower and deposited aluminum amount was relatively less compared with Al13. However, the total deposited mass of Al30 was much higher than that of Al13, which was attributed to the deposition of particulate aluminum matters with much higher hydration state. Compared with stationary condition, stirring could significantly enhance the deposition process, while the effect of pH on deposition was relatively weak in the near neutral range of 6.7 to 8.7.

  16. Deposition behavior of residual aluminum in drinking water distribution system: Effect of aluminum speciation.

    PubMed

    Zhang, Yue; Shi, Baoyou; Zhao, Yuanyuan; Yan, Mingquan; Lytle, Darren A; Wang, Dongsheng

    2016-04-01

    Finished drinking water usually contains some residual aluminum. The deposition of residual aluminum in distribution systems and potential release back to the drinking water could significantly influence the water quality at consumer taps. A preliminary analysis of aluminum content in cast iron pipe corrosion scales and loose deposits demonstrated that aluminum deposition on distribution pipe surfaces could be excessive for water treated by aluminum coagulants including polyaluminum chloride (PACl). In this work, the deposition features of different aluminum species in PACl were investigated by simulated coil-pipe test, batch reactor test and quartz crystal microbalance with dissipation monitoring. The deposition amount of non-polymeric aluminum species was the least, and its deposition layer was soft and hydrated, which indicated the possible formation of amorphous Al(OH)3. Al13 had the highest deposition tendency, and the deposition layer was rigid and much less hydrated, which indicated that the deposited aluminum might possess regular structure and self-aggregation of Al13 could be the main deposition mechanism. While for Al30, its deposition was relatively slower and deposited aluminum amount was relatively less compared with Al13. However, the total deposited mass of Al30 was much higher than that of Al13, which was attributed to the deposition of particulate aluminum matters with much higher hydration state. Compared with stationary condition, stirring could significantly enhance the deposition process, while the effect of pH on deposition was relatively weak in the near neutral range of 6.7 to 8.7. PMID:27090705

  17. 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...

  18. High energy density aluminum battery

    DOEpatents

    Brown, Gilbert M.; Paranthaman, Mariappan Parans; Dai, Sheng; Dudney, Nancy J.; Manthiram, Arumugan; McIntyre, Timothy J.; Sun, Xiao-Guang; Liu, Hansan

    2016-10-11

    Compositions and methods of making are provided for a high energy density aluminum battery. The battery comprises an anode comprising aluminum metal. The battery further comprises a cathode comprising a material capable of intercalating aluminum or lithium ions during a discharge cycle and deintercalating the aluminum or lithium ions during a charge cycle. The battery further comprises an electrolyte capable of supporting reversible deposition and stripping of aluminum at the anode, and reversible intercalation and deintercalation of aluminum or lithium at the cathode.

  19. 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

  20. Is the Aluminum Hypothesis dead?

    PubMed

    Lidsky, Theodore I

    2014-05-01

    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.

  1. 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…

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. Conference Summary

    NASA Technical Reports Server (NTRS)

    Harrington, James L., Jr.

    2000-01-01

    Celebrations and special events were in order this year as the Minority University-Space Interdisciplinary Network (MU-SPIN) Program and NASA's Minority University Research and Education Division (MURED) both reached their 10th anniversaries. In honor of this occasion, the 2000 Annual Users' Conference held at Morris Brown College (MBC) in Atlanta, Georgia, September 11-15, 2000, was the first to be jointly hosted by MU-SPIN and MURED. It was particularly fitting that this anniversary should fall in the year 2000. The start of the new millennium propelled us to push bold new ideas and renew our commitment to minority university participation in all areas of NASA. With the theme 'Celebrating Our Tenth Year With Our Eyes on the Prize,' the conference provided a national forum for showcasing successful MU-SPIN and MURED Program (MUREP) experiences to enhance faculty/student development in areas of scientific and technical research and education. Our NASA-relevant conference agenda resulted in a record-breaking 220 registered attendees. Using feedback from past participants, we designed a track of student activities closely tailored to their interests. The resulting showcase of technical assistance and best practices set a new standard for our conferences in the years to come. This year's poster session was our largest ever, with over 50 presentations from students, faculty, and teachers. Posters covered a broad range of NASA activities from 'A Study of the Spiral Galaxy M101' to 'Network Cabling Characteristics.'

  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. Effect of trace elements vanadium and nickel on iron intermetallic phases formation and distribution in DC cast 5xxx series aluminum ingots

    NASA Astrophysics Data System (ADS)

    Li, Gaofeng

    AA5657 alloy is one of the important members of 5xxx-series alloys. It has application in many fields as packing, electricity, architectural, and printing. These applications require high quality surface finishing, and the alloy ingots require homogeneous microstructure. In the industry of DC (direct-chill) casting of 1xxx and 5xxx-series aluminium ingots, there exist different cooling rates from the casting surface to the ingot center. Thus, different Fe intermetallic phases such as AlmFe, Al6Fe, alpha-AlFeSi and Al3Fe can form preferentially in different positions of the ingot. The Fe intermetallic phase transition in DC casting ingot may cause microstructure inhomogeneities, which in turn cause the so called fir-tree zones (FTZs) in the ingots as well as streaks and bands on the Al sheets. Nowadays, with the increase of impurity in aluminium smelting raw materials (coke, alumina, etc.), the levels of trace elements present in the primary metal is gradually increasing. The impact of this increase on the aluminium transformation process and the final products is uncertain. Thus, there is a clear need to better understand these impacts, which will allow identifying ways to mitigate the negative impacts. The study presented in this thesis was performed on AA5657 alloys to study the effect of trace elements V and Ni on Fe intermetallic phases formation and distribution. A slice of AA1050 alloy ingot with visible FTZs was also studied to characterize the Fe intermetallic phases transition across the FTZs. A DC simulator was built in the lab, which can reproduce the solidification conditions in the sub-surface regions of industry ingots. The methods for the characterization of Fe intermetallic particles were developed in this research. AlmFe, Al6Fe, alpha-AlFeSi and alpha-Al3Fe intermetallic phases were successfully identified by using Deep-etching method, EDS and EBSD technique in combination. Quantitative analysis of the Fe intermetallic particles was carried out by

  9. 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.

  10. A Study on Formation and Thermal Stability of Nano-sized Oxide Clusters in Mechanically Alloyed Nickel Aluminum for High Temperature Applications

    NASA Astrophysics Data System (ADS)

    Kim, Yong-Deog

    the thermal stability during an extensive matrix of long-term thermal annealing. In particular, the size, number density and composition of nano-clusters were assessed. While improvements in strength were obtained in the advanced NiAl ODS alloys, and the higher strength persisted through thermal annealing for 100 hrs at 1723K, characterization revealed the presence of Al in the oxide precipitate phases. The Al incorporation is believed detrimental to the formation of a high density of thermally stable Y-Ti-O nanoscale precipitates.

  11. Proceedings of the Seventh Applied Diamond Conference/Third Frontier Carbon Technology Joint Conference (ADC/FCT 2003). Supplement 1

    NASA Technical Reports Server (NTRS)

    Murakawa, M. (Editor); Miyoshi, K. (Editor); Koga, Y. (Editor); Schaefer, L. (Editor); Tzeng, Y. (Editor)

    2003-01-01

    This document contains 2 reports which were presented at the Seventh Applied Diamond Conference/Third Frontier Carbon Technology Joint Conference. The topics discuss the formation of C-N nanofibers as well as the characterization of diamond thin films.

  12. 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)

  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 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.

  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. 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).

  17. 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.

  18. Next conference

    NASA Astrophysics Data System (ADS)

    Hexemer, Alexander; Toney, Michael F.

    2010-11-01

    After the successful conference on Synchrotron Radiation in Polymer Science (SRPS) in Rolduc Abbey (the Netherlands), we are now looking forward to the next meeting in this topical series started in 1995 by H G Zachmann, one of the pioneers of the use of synchrotron radiation techniques in polymer science. Earlier meetings were held in Hamburg (1995), Sheffield (2002), Kyoto (2006), and Rolduc (2009). In September of 2012 the Synchrotron Radiation and Polymer Science V conferences will be organized in a joint effort by the SLAC National Accelerator Laboratory and Lawrence Berkeley National Laboratory. Stanford Linear Accelerator Laboratory Stanford Linear Accelerator Laboratory Advanced Light Source at LBL Advanced Light Source at LBL The conference will be organised in the heart of beautiful San Francisco. The program will consist of invited and contributed lectures divided in sessions on the use of synchrotron SAXS/WAXD, imaging and tomography, soft x-rays, x-ray spectroscopy, GISAXS and reflectivity, micro-beams and hyphenated techniques in polymer science. Poster contributions are more than welcome and will be highlighted during the poster sessions. Visits to both SLAC as well as LBL will be organised. San Francisco can easily be reached. It is served by two major international airports San Francisco International Airport and Oakland International Airport. Both are being served by most major airlines with easy connections to Europe and Asia as well as national destinations. Both also boast excellent connections to San Francisco city centre. We are looking forward to seeing you in the vibrant city by the Bay in September 2012. Golden gate bridge Alexander Hexemer Lawrence Berkeley National Laboratory, Advanced Light Source, Berkeley, CA 94720, USA Michael F Toney Stanford Synchrotron Radiation Lightsource, Menlo Pk, CA 94025, USA E-mail: ahexemer@lbl.gov, mftoney@slac.stanford.edu

  19. Conference Summary

    NASA Astrophysics Data System (ADS)

    Ellis, R. S.

    2008-10-01

    This first Subaru international conference has highlighted the remarkably diverse and significant contributions made using the 8.2m Subaru telescope by both Japanese astronomers and the international community. As such, it serves as a satisfying tribute to the pioneering efforts of Professors Keiichi Kodaira and Sadanori Okamura whose insight and dedication is richly rewarded. Here I try to summarize the recent impact of wide field science in extragalactic astronomy and cosmology and take a look forward to the key questions we will address in the near future.

  20. Conferences revisited

    NASA Astrophysics Data System (ADS)

    Radcliffe, Jonathan

    2008-08-01

    Way back in the mid-1990s, as a young PhD student, I wrote a Lateral Thoughts article about my first experience of an academic conference (Physics World 1994 October p80). It was a peach of a trip - most of the lab decamped to Grenoble for a week of great weather, beautiful scenery and, of course, the physics. A whole new community was there for me to see in action, and the internationality of it all helped us to forget about England's non-appearance in the 1994 World Cup finals.

  1. Safety evaluation of dietary aluminum.

    PubMed

    Soni, M G; White, S M; Flamm, W G; Burdock, G A

    2001-02-01

    Aluminum is a nonessential metal to which humans are frequently exposed. Aluminum in the food supply comes from natural sources, water used in food preparation, food ingredients, and utensils used during food preparations. The amount of aluminum in the diet is small, compared with the amount of aluminum in antacids and some buffered analgesics. The healthy human body has effective barriers (skin, lungs, gastrointestinal tract) to reduce the systemic absorption of aluminum ingested from water, foods, drugs, and air. The small amount of aluminum (<1%) that is systemically absorbed is excreted principally in the urine and, to a lesser extent, in the feces. No reports of dietary aluminum toxicity to healthy individuals exist in the literature. Aluminum can be neurotoxic, when injected directly into the brains of animals and when accidentally introduced into human brains (by dialysis or shrapnel). A study from Canada reports cognitive and other neurological deficits among groups of workers occupationally exposed to dust containing high levels of aluminum. While the precise pathogenic role of aluminum in Alzheimer's disease (AD) remains to be defined, present data do not support a causative role for aluminum in AD. High intake of aluminum from antacid for gastrointestinal ailments has not been reported to cause any adverse effects and has not been correlated with neurotoxicity or AD. Foods and food ingredients are generally the major dietary sources of aluminum in the United States. Cooking in aluminum utensils often results in statistically significant, but relatively small, increases in aluminum content of food. Common aluminum-containing food ingredients are used mainly as preservatives, coloring agents, leavening agents, anticaking agents, etc. Safety evaluation and approval of these ingredients by the Food and Drug Administration indicate that these aluminum-containing compounds are safe for use in foods.

  2. New Process for Grain Refinement of Aluminum. Final Report

    SciTech Connect

    Dr. Joseph A. Megy

    2000-09-22

    A new method of grain refining aluminum involving in-situ formation of boride nuclei in molten aluminum just prior to casting has been developed in the subject DOE program over the last thirty months by a team consisting of JDC, Inc., Alcoa Technical Center, GRAS, Inc., Touchstone Labs, and GKS Engineering Services. The Manufacturing process to make boron trichloride for grain refining is much simpler than preparing conventional grain refiners, with attendant environmental, capital, and energy savings. The manufacture of boride grain refining nuclei using the fy-Gem process avoids clusters, salt and oxide inclusions that cause quality problems in aluminum today.

  3. 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. ...

  4. Process for anodizing aluminum foil

    SciTech Connect

    Ball, J.A.; Scott, J.W.

    1984-11-06

    In an integrated process for the anodization of aluminum foil for electrolytic capacitors including the formation of a hydrous oxide layer on the foil prior to anodization and stabilization of the foil in alkaline borax baths during anodization, the foil is electrochemically anodized in an aqueous solution of boric acid and 2 to 50 ppm phosphate having a pH of 4.0 to 6.0. The anodization is interrupted for stabilization by passing the foil through a bath containing the borax solution having a pH of 8.5 to 9.5 and a temperature above 80/sup 0/ C. and then reanodizing the foil. The process is useful in anodizing foil to a voltage of up to 760 V.

  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. Drinking water aluminum and bioavailability

    SciTech Connect

    Reiber, S.H.; Kukull, W.; Standish-Lee, P.

    1995-05-01

    This article discusses chemical considerations relative to aluminum uptake in the body and reviews aluminum concentrations, species, and distribution in natural and treated waters. The issues of bioavailability and the likelihood that aluminum in drinking water is more readily assimilated than other forms of aluminum is reviewed and rejected based on issues of solubility and likely chemical transformations that take place in the human gut.

  7. Fluorescent complex of pyoverdin with aluminum.

    PubMed

    del Olmo, A; Caramelo, C; SanJose, C

    2003-12-01

    When a pyoverdin (PV), (a siderophore) from Pseudomonas fluorescens, binds aluminum 1:1, its natural fluorescence almost doubles, whereas PV-Fe is non-fluorescent. Complex formation allows [Al] determination down to 1 mug/l. Fe(III) in the sample interferes with [Al] determination, but added after PV, improves the assay's performance. Ascorbic acid does not eliminate Fe(III) interference. PV-Al fluorescence could have analytical and toxicological applications. PMID:14568244

  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 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.

  10. 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.

  11. 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.

  12. 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)

  13. 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.

  14. Aluminum Elicits Exocellular Phosphatidylethanolamine Production in Pseudomonas fluorescens

    PubMed Central

    Appanna, V. D.; Pierre, M. S.

    1996-01-01

    Pseudomonas fluorescens ATCC 13525 was found to grow in a minimal mineral medium supplemented with millimolar amounts of aluminum, a known environmental toxicant. During the stationary phase of growth, the trivalent metal was localized in a phosphatidylethanolamine (PE)-containing residue. The concentration of PE in pellets ranged from 1.7 to 13.9 mg ml of culture(sup-1) in media supplemented with 1 to 30 mM aluminum. Although the gelatinous residue was observed during the stationary phase of growth, ultracentrifugation and dialysis experiments revealed that PE was produced from earlier stages of incubation and was associated with aluminum. A sharp diminution in the levels of PE and aluminum in the spent fluid was concomitant with the formation of the insoluble deposit. The aluminum content of the soluble cellular fraction increased during growth and reached an optimum of 1.85 mM of test metal at 45 h in cultures with 15 mM aluminum. Further incubation, however, led to a marked decrease in the cellular aluminum content, and during the stationary phase of growth, only trace amounts of the trivalent metal were detected in this fraction. When 45-h cells were incubated in fresh citrate medium, most of the intracellular aluminum was secreted in the spent fluid and citrate was rapidly consumed. Aluminum efflux was also observed in cultures in which d-glucose was substituted for citrate. However, no efflux of this trivalent metal was evident in media devoid of either citrate or d-glucose. Scanning electron microscopic studies and X-ray energy-dispersive analyses of the dialyzed supernatant aided in the visualization of nodule-like aluminum- and phosphorus-rich bodies associated with thread-like carbon-, oxygen-, and phosphorus-containing structures. Transmission electron microscopic and electron energy loss spectroscopic analyses revealed the presence of aluminum within bacteria after 45 h of incubation. Cells harvested after aluminum insolubilization did not shown

  15. 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.

  16. 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.

  17. Inhibition of Aluminum Oxyhydroxide Precipitation with Citric Acid

    SciTech Connect

    Dabbs, Daniel M.; Ramachandran, Usha; Lu, Sang; Liu, Jun; Wang, Li Q.; Aksay, Ilhan A.

    2005-12-06

    Citric acid has been shown to act as an agent for increasing the solubility of aluminum oxyhydroxides in aqueous solutions of high (>2.47 mol/mol) hydroxide-to-aluminum ratios. Conversely, citric acid also colloidally stabilizes particles in aqueous suspensions of aluminum-containing particles. Solutions of aluminum chloride, with and without citric acid added, were titrated with NaO(aq). The presence and size of particles were determined using quasi-elastic light scattering. In solutions that contained no citric acid, particles formed instantaneously when NaOH(aq) was added but these were observed to rapidly diminish in size, disappearing at OH/Al ratios below 2.5 mol/mol. When the OH/Al ratio was raised beyond 2.5 by addingmoreNaOH(aq), suspensions of colloidally stable particles formed. Large polycations containing 13 aluminum atoms were detected by 27Al solution NMR in citric-acid-free solutions with OH/Al ratios slightly lower than 2.5. In comparison, adding citric acid to solutions of aluminum chloride inhibited the formation of large aluminum-containing polycations. The absence of the polycations prevents or retards the subsequent formation of particles, indicating that the polycations, when present, act as seeds to the formation of new particles. Particles did not form in solutions with a citric acid/aluminum ratio of 0.8 until sufficient NaOH(aq) was added to raise the OH/Al ratio to 3.29. By comparison, lower amounts of citric acid did not prevent particles from forming but did retard the rate of growth.

  18. Filamentation and spatiotemporal distribution of extracellular polymeric substances: role on X.fastidiosa single cell adhesion and biofilm formation (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Janissen, Richard; Murillo, Duber M.; Niza, Barbara; Sahoo, Prasana K.; Monteiro, Moniellen P.; César, Carlos L.; Carvalho, Hernandes F.; de Souza, Alessandra A.; Cotta, Monica A.

    2016-04-01

    Biofilms can be defined as a community of microorganisms attached to a surface, living embedded in a self- produced matrix of hydrated extracellular polymeric substances (EPS) which comprises most of the biofilm mass. We have recently used an extensive pool of microscopy techniques (confocal fluorescence, electron and scanning probe microscopies) at the micro and nanoscales in order to create a detailed temporal observation of Xylella fastidiosa biofilm formation, using both wild type strain and Green Fluorescent Protein (GFP)-modified cells of this citrus phytopathogen. We have identified three different EPS compositions, as well as their spatial and temporal distribution from single cell to mature biofilm formation stages. In the initial adhesion stage, soluble-EPS (S-EPS) accumulates at cell polar regions and forms a surface layer which facilitates irreversible cell attachment and cell cluster formation. These small clusters are subsequently connected by filamentous cells; further S-EPS surface coverage facilitates cell attachment and form filaments, leading to a floating framework of mature biofilms. The important role of EPS in X.fastidiosa biology was further investigated by imunolabelling experiments to detect the distribution of XadA1 adhesin, which is expressed in early stages of biofilm formation and released in outer membrane vesicles. This protein is located mainly in S-EPS covered areas, as well as on the filaments, indicating a molecular pathway to the enhanced cell attachment previously observed. These results suggest that S-EPS may thus represent an important target for disease control, slow plant colonization by the bacteria, keeping the plant more productive in the field.

  19. Aluminum-catalyzed silicon nanowires: Growth methods, properties, and applications

    NASA Astrophysics Data System (ADS)

    Hainey, Mel F.; Redwing, Joan M.

    2016-12-01

    Metal-mediated vapor-liquid-solid (VLS) growth is a promising approach for the fabrication of silicon nanowires, although residual metal incorporation into the nanowires during growth can adversely impact electronic properties particularly when metals such as gold and copper are utilized. Aluminum, which acts as a shallow acceptor in silicon, is therefore of significant interest for the growth of p-type silicon nanowires but has presented challenges due to its propensity for oxidation. This paper summarizes the key aspects of aluminum-catalyzed nanowire growth along with wire properties and device results. In the first section, aluminum-catalyzed nanowire growth is discussed with a specific emphasis on methods to mitigate aluminum oxide formation. Next, the influence of growth parameters such as growth temperature, precursor partial pressure, and hydrogen partial pressure on nanowire morphology is discussed, followed by a brief review of the growth of templated and patterned arrays of nanowires. Aluminum incorporation into the nanowires is then discussed in detail, including measurements of the aluminum concentration within wires using atom probe tomography and assessment of electrical properties by four point resistance measurements. Finally, the use of aluminum-catalyzed VLS growth for device fabrication is reviewed including results on single-wire radial p-n junction solar cells and planar solar cells fabricated with nanowire/nanopyramid texturing.

  20. Aluminum electroplating on steel from a fused bromide electrolyte

    SciTech Connect

    Prabhat K. Tripathy; Laura A. Wurth; Eric J. Dufek; Toni Y. Gutknecht; Natalie J. Gese; Paula Hahn; Steven M. Frank; Guy L. Frederickson; J. Stephen Herring

    2014-08-01

    A quaternary bromide bath (LiBr–KBr–CsBr–AlBr3) was used to electro-coat aluminum on steel substrates. The electrolytewas prepared by the addition of AlBr3 into the eutectic LiBr–KBr–CsBr melt. A smooth, thick, adherent and shiny aluminum coating could be obtained with 80 wt.% AlBr3 in the ternary melt. The SEM photographs of the coated surfaces suggest the formation of thick and dense coatings with good aluminum coverage. Both salt immersion and open circuit potential measurement suggested that the coatings did display a good corrosionresistance behavior. Annealing of the coated surfaces, prior to corrosion tests, suggested the robustness of the metallic aluminum coating in preventing the corrosion of the steel surfaces. Studies also indicated that the quaternary bromide plating bath can potentially provide a better aluminumcoating on both ferrous and non-ferrous metals, including complex surfaces/geometries.

  1. 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.

  2. Improved cryogenic aluminum mirrors

    NASA Astrophysics Data System (ADS)

    Vukobratovich, Daniel; Don, Ken; Sumner, Richard E.

    1998-09-01

    Optical surface deformation of metal mirrors used at cryogenic temperatures is reduced through the use of a new process of plating amorphous aluminum on aluminum. The AlumiPlateTM process (produced by AlumiPlate, Inc. in Minneapolis, MN) plates a layer of 99.9+% high purity aluminum about 125 micrometers thick atop the substrate. Very good surface finishes are produced by direct diamond turning of the plating, with some samples below 40 angstroms RMS. Optical testing of a 175-mm diameter, 550-mm optical radius of curvature 6061-T651/AlumiPlateTM aluminum sphere was performed at 65 K to determine cryogenic optical surface figure stability. In five cycles from 300 to 65 K, an average optical surface change of 0.047 wave RMS (1 wave equals 633 nm) was observed. A total optical figure change of 0.03 wave RMS at 65 K was observed from the first to last cycle. The cause of this relatively small long-term change is not yet determined. The test mirror is bi-concave, with a semi- kinematic toroidal mount, and is machined from the axis of a billet. An `uphill quench' heat treatment consisting of five cycles from liquid nitrogen to boiling water temperatures is used to minimize residual stress in the test mirror. Initial diamond turning of the mirror by the Optical Filter Corp., Keene, NH, produced a 300 K unmounted optical surface figure of 0.380 wave peak-to-valley and 0.059 wave RMS. A second effort at diamond turning by II-VI, Inc., Saxonburg, PA produced a 300 K optical figure of 0.443 wave peak-to-valley and 0.066 wave RMS, with a surface roughness varying from 29 to 42 angstroms.

  3. Degradation Mechanisms in Aluminum Matrix Composites: Alumina/Aluminum and Boron/Aluminum. Ph.D. Thesis - North Carolina State Univ. at Raleigh

    NASA Technical Reports Server (NTRS)

    Olsen, G. C.

    1981-01-01

    The effects of fabrication and long term thermal exposure (up to 10,000 hours at 590 K) on two types of aluminum matrix composites were examined. An alumina/aluminum composite, was made of continuous alpha Al2O3 fibers in a matrix of commercially pure aluminum alloyed with 2.8% lithium. The mechanical properties of the material, the effect of isothermal exposure, cyclic thermal exposure, and fatigue are presented. Two degradation mechanisms are identified. One was caused by formation of a nonstoichiometric alumina during fabrication, the other by a loss of lithium to a surface reaction during long term thermal exposure. The other composite, boron/aluminum, made of boron fibers in an aluminum matrix, was investigated using five different aluminum alloys for the matrices. The mechanical properties of each material and the effect of isothermal and cyclic thermal exposure are presented. The effects of each alloy constituent on the degradation mechanisms are discussed. The effects of several reactions between alloy constituents and boron fibers on the composite properties are discussed.

  4. Silicon diffusion in aluminum for rear passivated solar cells

    SciTech Connect

    Urrejola, Elias; Peter, Kristian; Plagwitz, Heiko; Schubert, Gunnar

    2011-04-11

    We show that the lateral spread of silicon in a screen-printed aluminum layer increases by (1.50{+-}0.06) {mu}m/ deg. C, when increasing the peak firing temperature within an industrially applicable range. In this way, the maximum spread limit of diffused silicon in aluminum is predictable and does not depend on the contact area size but on the firing temperature. Therefore, the geometry of the rear side pattern can influence not only series resistance losses within the solar cell but the process of contact formation itself. In addition, too fast cooling lead to Kirkendall void formations instead of an eutectic layer.

  5. Avoidance of aluminum by rainbow trout

    SciTech Connect

    Exley, C.

    2000-04-01

    Aluminum is the principal toxicant in fish in acid waters. The ability to avoid Al, particularly at low concentrations, would confer a considerable ecological advantage, but previous research into avoidance of Al has produced mixed results. The author used a cylindrical perspex tank, 150 cm in length, to study avoidance of Al by rainbow trout fry. The fish avoided Al, and their response was dependent on pH. Avoidance that was demonstrated at pHs of 5.00, 5.50, 5.50, and 5.75 was abolished at a pH of 6.00. Fry avoided very low Al concentrations being sensitive to [Al] > 1.00 {micro}mol L{sup {minus}1} at a pH of 5.00. This unequivocal demonstration of avoidance by rainbow trout fry of Al may have important implications for the ecology of indigenous fish populations in surface waters impacted by acidic deposition.

  6. 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

  7. 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....

  8. 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....

  9. 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....

  10. 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....

  11. 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....

  12. Exposure assessment of aluminum arc welding radiation.

    PubMed

    Peng, Chiung-yu; Lan, Cheng-hang; Juang, Yow-jer; Tsao, Ta-ho; Dai, Yu-tung; Liu, Hung-hsin; Chen, Chiou-jong

    2007-10-01

    The purpose of this study is to evaluate the non-ionizing radiation (NIR) exposure, especially optical radiation levels, and potential health hazard from aluminum arc welding processes based on the American Conference of Governmental Industrial Hygienists (ACGIH) method. The irradiance from the optical radiation emissions can be calculated with various biological effective parameters [i.e., S(lambda), B(lambda), R(lambda)] for NIR hazard assessments. The aluminum arc welding processing scatters bright light with NIR emission including ultraviolet radiation (UVR), visible, and infrared spectra. The UVR effective irradiance (Eeff) has a mean value of 1,100 microW cm at 100 cm distance from the arc spot. The maximum allowance time (tmax) is 2.79 s according to the ACGIH guideline. Blue-light hazard effective irradiance (EBlue) has a mean value of 1840 microW cm (300-700 nm) at 100 cm with a tmax of 5.45 s exposure allowance. Retinal thermal hazard effective calculation shows mean values of 320 mW cm(-2) sr(-1) and 25.4 mW (cm-2) (380-875 nm) for LRetina (spectral radiance) and ERetina (spectral irradiance), respectively. From this study, the NIR measurement from welding optical radiation emissions has been established to evaluate separate types of hazards to the eye and skin simultaneously. The NIR exposure assessment can be applied to other optical emissions from industrial sources. The data from welding assessment strongly suggest employees involved in aluminum welding processing must be fitted with appropriate personal protection devices such as masks and gloves to prevent serious injuries of the skin and eyes upon intense optical exposure.

  13. 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.

  14. 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.

  15. Microstructure of Modified Layer Produced Using Aluminum Oxy-Hydroxide Nanostructured Powders

    NASA Astrophysics Data System (ADS)

    Kuznetsov, M. A.; Shlyakhova, G. V.; Danilov, V. I.; Zernin, E. A.; Dementyev, S. V.

    2016-04-01

    The paper provides the results of experimental research into the influence of aluminum oxy-hydroxide nano-structured powders on the microstructure of modified layers. It has been demonstrated aluminum oxy-hydroxide nano-structured powders AlO(OH) applied as modifiers bring about the decrease in dendrite dimensions, support equilibrium microstructure formation, and cause the growth of microhardness.

  16. Plant adaptation to acid soils: the molecular basis for crop aluminum resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aluminum (Al) toxicity on acid soils is a significant limitation to crop production worldwide, as approximately 50% of the world’s potentially arable soils are acidic. Because acid soils are such an important constraint to agriculture, understanding the mechanisms and genes conferring resistance to ...

  17. Aluminum-lithium for aerospace

    SciTech Connect

    Fielding, P.S.; Wolf, G.J.

    1996-10-01

    Aluminum-lithium alloys were developed primarily to reduce the weight of aircraft and aerospace structures. Lithium is the lightest metallic element, and each 1% of lithium added to aluminum reduces alloy density by about 3% and increases modulus by about 5%. Though lithium has a solubility limit of 4.2% in aluminum, the amount of lithium ranges between 1 and 3% in commercial alloys. Aluminum-lithium alloys are most often selected for aerospace components because of their low density, high strength, and high specific modulus. However, other applications now exploit their excellent fatigue resistance and cryogenic toughness.

  18. 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.

  19. Effects of organic solutes on chemical reactions of aluminum

    USGS Publications Warehouse

    Lind, Carol J.; Hem, John David

    1975-01-01

    Concentrations of organic matter in the general range of 1-10 milligrams per litre organic carbon are common in natural water, and many naturally occurrin7 organic compounds form aluminum complexes. The aluminum concentrations in near-neutral pH solutions may be 10-100 times higher than the values predicted from solubility data if formation of such organic complexes is ignored. The processes of polymerization of aluminum hydroxide and precipitation of gibbsite are inhibited by the presence of the organic flavone compound quercetin in concentrations as low as 10 x -5.3 mole per litre. Quercetin forms a complex, with a probable molar ratio of 1:2 aluminum to quercetin, that has a formation constant (f12) of about 10 12. A complex with a higher aluminum-quercetin ratio also was observed, but this material tends to evolve into a compound of low solubility that removes aluminum from solution. In the presence of both dissolved aluminum and aqueous silica, low concentrations of quercetin improved the yield of crystallized kaolinite and halloysite. Small amounts of well-shaped kaolinite and halloysite crystals were identified by electron microscopy in solutions with pH's in the range 6.5-8.5 after 155 days aging in one experimer t and 481 days aging in a repeated experiment. The bulk of the precipitated material was amorphous to X-rays, and crystalline material was too small a proportion of the total to give identifiable X-ray diffraction peaks. The precipitates had aluminum-silicon ratios near 1, and their solubility corresponded to that found by Hem, Roberson, Lind, and Polzer (1973) for similar aluminosilicate precipitated in the absence of organic solutes. The improved yield of crystalline material obtained in the presence of quercetin probably is the result of the influence of the organic compound on the aluminum hydroxide polymerization process. Natural water containing color imparted by organic material tends to be higher in aluminum than would be predicted by p

  20. Fifth international fungus spore conference

    SciTech Connect

    Timberlake, W.E.

    1993-04-01

    This folio contains the proceedings of the Fifth International Fungal Spore Conference held August 17-21, 1991 at the Unicoi State Park at Helen, Georgia. The volume contains abstracts of each oral presentation as well as a collection of abstracts describing the poster sessions. Presentations were organized around the themes (1) Induction of Sporulation, (2) Nuclear Division, (3) Spore Formation, (4) Spore Release and Dispersal, and (4) Spore Germination.

  1. Conference summary

    NASA Astrophysics Data System (ADS)

    Harwit, Martin

    To do justice to so many interesting contributions, both in the form of papers presented as talks and posters represented only by titles in these proceedings, will be difficult. Rather than attempting to list contributions from the individual areas in a representative fashion, I will attempt to see how a few of the striking contributions fit into, or alter, our views on major questions we have been trying to answer during the past few decades — questions dealing with the structure and evolution of the universe, the formation of galaxies and stars, and the origins of the solar system, in short everything from Comets to Cosmology — though I will reverse the order, starting here with cosmological questions and ending up with comets, or rather with zodiacal dust.

  2. SIAM conference on applications of dynamical systems

    SciTech Connect

    Not Available

    1992-01-01

    A conference (Oct.15--19, 1992, Snowbird, Utah; sponsored by SIAM (Society for Industrial and Applied Mathematics) Activity Group on Dynamical Systems) was held that highlighted recent developments in applied dynamical systems. The main lectures and minisymposia covered theory about chaotic motion, applications in high energy physics and heart fibrillations, turbulent motion, Henon map and attractor, integrable problems in classical physics, pattern formation in chemical reactions, etc. The conference fostered an exchange between mathematicians working on theoretical issues of modern dynamical systems and applied scientists. This two-part document contains abstracts, conference program, and an author index.

  3. 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.

  4. 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.

  5. Characterization of ultradispersed aluminum

    SciTech Connect

    Simpson, R.L.; Maienschein, J.L.; Swansiger, R.W.; Garcia, F.; Darling, D.H.

    1994-12-08

    Samples of ultradispersed Al were received, which were produced by electrically exploding Al wires in argon. These samples comprised very small particles that were not significantly oxidized and that were stable in air. Particle morphology were studied with SE, micropycnometry, and gas adsorption surface area. Composition were determined using various techniques, as were thermal stability and reaction exotherms. The inexplicable reports of an Al-Ar compound and of an exothermic reaction were not confirmed. The material is a stable, nonoxidized, small-particle, highly reactive form of aluminum that is of interest in energetic materials formulations.

  6. Aluminum nitride grating couplers.

    PubMed

    Ghosh, Siddhartha; Doerr, Christopher R; Piazza, Gianluca

    2012-06-10

    Grating couplers in sputtered aluminum nitride, a piezoelectric material with low loss in the C band, are demonstrated. Gratings and a waveguide micromachined on a silicon wafer with 600 nm minimum feature size were defined in a single lithography step without partial etching. Silicon dioxide (SiO(2)) was used for cladding layers. Peak coupling efficiency of -6.6 dB and a 1 dB bandwidth of 60 nm have been measured. This demonstration of wire waveguides and wideband grating couplers in a material that also has piezoelectric and elasto-optic properties will enable new functions for integrated photonics and optomechanics.

  7. Effect of grain orientation on aluminum relocation at incipient melt conditions

    SciTech Connect

    Yilmaz, Nadir; Vigil, Francisco M.; Vigil, Miquela S.; Branam, Robert; Tolendino, Greg; Gill, Walt; Burl Donaldson, A.

    2015-09-01

    Aluminum is commonly used for structural applications in the aerospace industry because of its high strength in relation to its weight. It is necessary to understand the mechanical response of aluminum structures at elevated temperatures such as those experienced in a fire. Additionally, aluminum alloys exhibit many complicated behaviors that require further research and understanding, such as aluminum combustion, oxide skin formation and creep behavior. This paper discusses the effect of grain orientation on aluminum deformation subjected to heating at incipient melt conditions. Experiments were conducted by applying a vertical compressive force to aluminum alloy 7075 block test specimens. Furthermore, compression testing was done on test specimens with the applied load on the long transverse and short transverse orientations. Our results showed that the grain orientation significantly influences aluminum’s strength and mode of failure.

  8. Effect of grain orientation on aluminum relocation at incipient melt conditions

    DOE PAGES

    Yilmaz, Nadir; Vigil, Francisco M.; Vigil, Miquela S.; Branam, Robert; Tolendino, Greg; Gill, Walt; Burl Donaldson, A.

    2015-09-01

    Aluminum is commonly used for structural applications in the aerospace industry because of its high strength in relation to its weight. It is necessary to understand the mechanical response of aluminum structures at elevated temperatures such as those experienced in a fire. Additionally, aluminum alloys exhibit many complicated behaviors that require further research and understanding, such as aluminum combustion, oxide skin formation and creep behavior. This paper discusses the effect of grain orientation on aluminum deformation subjected to heating at incipient melt conditions. Experiments were conducted by applying a vertical compressive force to aluminum alloy 7075 block test specimens. Furthermore,more » compression testing was done on test specimens with the applied load on the long transverse and short transverse orientations. Our results showed that the grain orientation significantly influences aluminum’s strength and mode of failure.« less

  9. Aluminum Citrate Prevents Renal Injury from Calcium Oxalate Crystal Deposition

    PubMed Central

    Besenhofer, Lauren M.; Cain, Marie C.; Dunning, Cody

    2012-01-01

    Calcium oxalate monohydrate crystals are responsible for the kidney injury associated with exposure to ethylene glycol or severe hyperoxaluria. Current treatment strategies target the formation of calcium oxalate but not its interaction with kidney tissue. Because aluminum citrate blocks calcium oxalate binding and toxicity in human kidney cells, it may provide a different therapeutic approach to calcium oxalate-induced injury. Here, we tested the effects of aluminum citrate and sodium citrate in a Wistar rat model of acute high-dose ethylene glycol exposure. Aluminum citrate, but not sodium citrate, attenuated increases in urea nitrogen, creatinine, and the ratio of kidney to body weight in ethylene glycol–treated rats. Compared with ethylene glycol alone, the addition of aluminum citrate significantly increased the urinary excretion of both crystalline calcium and crystalline oxalate and decreased the deposition of crystals in renal tissue. In vitro, aluminum citrate interacted directly with oxalate crystals to inhibit their uptake by proximal tubule cells. These results suggest that treating with aluminum citrate attenuates renal injury in rats with severe ethylene glycol toxicity, apparently by inhibiting calcium oxalate’s interaction with, and retention by, the kidney epithelium. PMID:23138489

  10. 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.

  11. Intelligent control of vacuum aluminum brazing

    SciTech Connect

    Zhong, G.; Pai, D.M.; Badgley, S.

    1995-06-01

    Vacuum brazing is a versatile modern day metal joining method. It usually includes vacuum producing, heating and residual gas analyzing systems. When used to join aluminum parts, the quality of the brazed joint is highly dependent on the residual gases in the vacuum, especially the residual oxygen and water vapor in the vacuum chamber which affect the formation of oxides. These vacuum environment brazing contaminants are reduced during the out-gassing processes of degassing and desorption during heating under vacuum. Exceeding the boundary limits of these contaminants causes unacceptable flow of braze filler in the joints during the brazing process. Identification of the quality control boundary for vacuum brazing of aluminum alloy makes computer control of vacuum brazing quality for aluminum alloys possible. The present study utilizes a residual gas analyzer (RGA) to monitor the partial pressures of residual gases during brazing. These data are transported to computer through the RS-232 interface port on the RGA, and used in real time to monitor the brazing quality by an algorithm based on the quality control boundary. If the quality is bad, the computer will send a ``hold`` signal to the heating system via another Rs-232 port until the environment is reestablished within the acceptable boundary.

  12. 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)

  13. 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)

  14. 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

  15. 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

    2015-07-09

    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.

  16. 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

  17. Photorefractive effect in undoped aluminum nitride.

    PubMed

    Nagai, Toru; Fujimura, Ryushi; Shimura, Tsutomu; Kuroda, Kazuo

    2010-07-01

    We report our observation of the photorefractive effect in undoped aluminum nitride. We measured the coupling constant and the formation rate as a function of pump intensity at a wavelength of 405 nm in a two-wave mixing experiment. The photorefractive gain coefficient was 0.47 cm(-1) at I = 6.9 W/cm(2), and the actual saturated value was probably larger than this. The time constant was 59 ms at I = 1.0 W/cm(2). In addition to a refractive index grating, an absorption grating was also formed, which is attributed mainly to an ionized trap density modulation process.

  18. The General Conference Mennonites.

    ERIC Educational Resources Information Center

    Ediger, Marlow

    General Conference Mennonites and Old Order Amish are compared and contrasted in the areas of physical appearance, religious beliefs, formal education, methods of farming, and home settings. General Conference Mennonites and Amish differ in physical appearance and especially in dress. The General Conference Mennonite men and women dress the same…

  19. Parent Conferences. Beginnings Workshop.

    ERIC Educational Resources Information Center

    Duffy, Roslyn; And Others

    1997-01-01

    Presents six workshop sessions on parent conferences: (1) "Parents' Perspectives on Conferencing" (R. Duffy); (2) "Three Way Conferences" (G. Zeller); (3) "Conferencing with Parents of Infants" (K. Albrecht); (4) "Conferencing with Parents of School-Agers" (L. G. Miller); (5) "Cross Cultural Conferences" (J. Gonzalez-Mena); and (6) "Working with…

  20. Spectrofluorimetric determination of trace aluminum in diluted hemodialysis solutions

    NASA Astrophysics Data System (ADS)

    Gündüz, S. Beniz; Küçükkolbaşý, Semahat; Atakol, Orhan; Kýlýç, Esma

    2005-03-01

    In this study, a spectrofluorimetric method has been developed for the determination of aluminum based on the formation of an aluminum complex with N, N'-disalicylidene-1,3-diamino-2-hydroxypropane (DSAHP). The most suitable pH, solvent medium, complex formation time, Schiff base concentration and temperature were determined. The excitation and emission wavelengths were 270 and 437 nm, respectively, in which the DSAHP-Al complex gave the maximum flurescence intensity at pH 3.0 and 6.0 in 50% dioxan-50% water medium. Under these conditions, calibration curves were obtained in three different linear limits, and was found that aluminum could be detected within the concentration limit of 0-10.0 μM and the lowest detection limit being 0.27 ng ml -1. The stochiometry of the DSAHP-Al complex was also determined spectrofluorimetrically under optimal conditions and the molar ratio of DSAHP-Al was calculated as 2:1. Using the developed method, aluminum was detected in hemodialysis solutions, and the results obtained were similar and comparable with those obtained using the method described in the British Pharmacopoeia within 95% confidence limits. This method can be used successfully for the routine determination of aluminum because it is quick, requires less amount of reactives, is sensitive, reliable and reproducible.

  1. Junction properties of aluminum/polypyrrole (polypyrrole derivatives) Schottky diodes

    NASA Astrophysics Data System (ADS)

    Singh, Ramadhar; Narula, Amarjeet K.

    1997-11-01

    The current-voltage characteristics of Schottky junctions formed by using aluminum on polypyrrole, poly(N-methyl pyrrole) and the copolymer poly(N-methyl pyrrole-pyrrole) have been investigated. The formation of the junctions has been confirmed by capacitance-voltage characteristics and Chot plots. The results have been explained on the basis of thermionic emission theory.

  2. Nanosized aluminum nitride hollow spheres formed through a self-templating solid-gas interface reaction

    SciTech Connect

    Zheng Jie Song Xubo; Zhang Yaohua; Li Yan; Li Xingguo; Pu Yikang

    2007-01-15

    Nanosized aluminum nitride hollow spheres were synthesized by simply heating aluminum nanoparticles in ammonia at 1000 deg. C. The as-synthesized sphere shells are polycrystalline with cavity diameters ranging from 15 to 100 nm and shell thickness from 5 to 15 nm. The formation mechanism can be explained by the nanoscale Kirkendall effect, which results from the difference in diffusion rates between aluminum and nitrogen. The Al nanoparticles served as both reactant and templates for the hollow sphere formation. The effects of precursor particle size and temperature were also investigated in terms of product morphology. Room temperature cathode luminescence spectrum of the nanosized hollow spheres showed a broad emission band centered at 415 nm, which is originated from oxygen related luminescence centers. The hollow structure survived a 4-h heat treatment at 1200 deg. C, exhibiting excellent thermal stability. - Graphical abstract: Nanosized aluminum nitride hollow spheres were synthesized by nitridation of aluminum nanoparticles at 1000 deg. C using ammonia.

  3. 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.

  4. 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.

  5. Aluminum anode for aluminum-air battery - Part I: Influence of aluminum purity

    NASA Astrophysics Data System (ADS)

    Cho, Young-Joo; Park, In-Jun; Lee, Hyeok-Jae; Kim, Jung-Gu

    2015-03-01

    2N5 commercial grade aluminum (99.5% purity) leads to the lower aluminum-air battery performances than 4N high pure grade aluminum (99.99% purity) due to impurities itself and formed impurity complex layer which contained Fe, Si, Cu and others. The impurity complex layer of 2N5 grade Al declines the battery voltage on standby status. It also depletes discharge current and battery efficiency at 1.0 V which is general operating voltage of aluminum-air battery. However, the impurity complex layer of 2N5 grade Al is dissolved with decreasing discharge voltage to 0.8 V. This phenomenon leads to improvement of discharge current density and battery efficiency by reducing self-corrosion reaction. This study demonstrates the possibility of use of 2N5 grade Al which is cheaper than 4N grade Al as the anode for aluminum-air battery.

  6. Dry machinability of aluminum alloys.

    SciTech Connect

    Shareef, I.; Natarajan, M.; Ajayi, O. O.; Energy Technology; Department of IMET

    2005-01-01

    Adverse effects of the use of cutting fluids and environmental concerns with regard to cutting fluid disposability is compelling industry to adopt Dry or near Dry Machining, with the aim of eliminating or significantly reducing the use of metal working fluids. Pending EPA regulations on metal cutting, dry machining is becoming a hot topic of research and investigation both in industry and federal research labs. Although the need for dry machining may be apparent, most of the manufacturers still consider dry machining to be impractical and even if possible, very expensive. This perception is mainly due to lack of appropriate cutting tools that can withstand intense heat and Built-up-Edge (BUE) formation during dry machining. The challenge of heat dissipation without coolant requires a completely different approach to tooling. Special tooling utilizing high-performance multi-layer, multi-component, heat resisting, low friction coatings could be a plausible answer to the challenge of dry machining. In pursuit of this goal Argonne National Labs has introduced Nano-crystalline near frictionless carbon (NFC) diamond like coatings (DLC), while industrial efforts have led to the introduction of composite coatings such as titanium aluminum nitride (TiAlN), tungsten carbide/carbon (WC/C) and others. Although, these coatings are considered to be very promising, they have not been tested either from tribological or from dry machining applications point of view. As such a research program in partnership with federal labs and industrial sponsors has started with the goal of exploring the feasibility of dry machining using the newly developed coatings such as Near Frictionless Carbon Coatings (NFC), Titanium Aluminum Nitride (TiAlN), and multi-layer multicomponent nano coatings such as TiAlCrYN and TiAlN/YN. Although various coatings are under investigation as part of the overall dry machinability program, this extended abstract deals with a systematic investigation of dry

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. Aluminum-air battery crystallizer

    SciTech Connect

    Maimoni, A.

    1987-01-01

    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 aluminum 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.

  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. Views from the 1995 ECC conference

    SciTech Connect

    Lowry, J.C.; Haegelin, J.K.; Underwood, J.K.

    1995-12-01

    The Engineering and Construction Contracting Division (ECC) of the AIChE held its 27th Annual Conference in Scottsdale, Arizona, Sept. 7--8, 1995. Each year the conference is attended by management representatives from manufacturers, producers, engineering and construction contractors, consultants and major equipment suppliers. The 1995 conference theme was, Applying Advanced Methodology to Improve Project Execution. What were the issues and recommendations resulting from the conference? Here are the composite results from the annual workshops, as well as some perspectives from three selected participants. The paper discusses modularization in the process industry, innovative construction practices, creation and use of 3-D models for the plant`s life cycle, alliances and pay-for-performance contracting, and new workshop formats, and ends with general views from selected participants.

  14. Fundamental studies on electrochemical production of dendrite-free aluminum and titanium-aluminum alloys

    NASA Astrophysics Data System (ADS)

    Pradhan, Debabrata

    A novel dendrite-free electrorefining of aluminum scrap was investigated by using AlCl3-1-Ethyl-3-methyl-imidazolium chloride (EMIC) ionic liquid electrolyte. Electrodeposition of aluminum were conducted on copper/aluminum cathodes at voltage of 1.5 V, temperatures (50-110°C), stirring rate (0-120 rpm), molar ratio (MR) of AlCl3:EMIC (1.25-2.0) and electrode surface modification (modified/unmodified). The study was focused to investigate the effect of process variables on deposit morphology, cathode current density and their role in production of dendrite-free aluminum. The deposits were characterized using scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). Modified electrodes and stirring rate (60 rpm) eliminate dendritic deposition by reducing cathode overpotential below critical overpotential (etacrt≈ -0.54 V) for dendrite formation. Pure aluminum (>99%) was deposited with current efficiency of 84-99%. Chronoamperometry study was conducted using AlCl3-EMIC and AlCl3-1-Butyl-3-methyl-imidazolium chloride (BMIC) (MR = 1.65:1) at 90°C to understand the mechanism of aluminum electrodeposition and find out diffusion parameter of electroactive species Al2C 7-. It was concluded that electrodeposition of aluminum is a diffusion controlled instantaneous nucleation process and diffusion coefficient of Al2C7- was found to be 5.2-6.9 x 10-11 m2/s and 2.2 x 10-11 m2/s for AlCl3-EMIC and AlCl3-BMIC, respectively. A novel production route of Ti-Al alloys was investigated using AlCl 3-BMIC-TiCl4 (MR = 2:1:0.019) and AlCl3-BMIC (MR = 2:1) electrolytes at constant voltages of 1.5-3.0 V and temperatures (70-125°C). Ti sheet was used as anode and cathode. Characterization of electrodeposited Ti-Al alloys was carried out using SEM, EDS, XRD and inductively coupled plasma-optical emission spectrometer (ICP-OES). Effect of voltage and temperature on cathode current density, current efficiency, composition and morphology of Ti

  15. A Case of Recurrent Renal Aluminum Hydroxide Stone

    PubMed Central

    Cakıroglu, Basri; Dogan, Akif Nuri; Tas, Tuncay; Gozukucuk, Ramazan; Uyanik, Bekir Sami

    2014-01-01

    Renal stone disease is characterized by the differences depending on the age, gender, and the geographic location of the patients. Seventy-five percent of the renal stone components is the calcium (Ca). The most common type of the stones is the Ca oxalate stones, while Ca phosphate, uric acid, struvite, and sistine stones are more rarely reported. Other than these types, triamterene, adenosine, silica, indinavir, and ephedrine stones are also reported in the literature as case reports. However, to the best of our knowledge, aluminum hydroxide stones was not reported reported before. Herein we will report a 38-years-old woman with the history of recurrent renal colic disease whose renal stone was determined as aluminum hydroxide stone in type. Aluminum mineral may be considered in the formation of kidney stones as it is widely used in the field of healthcare and cosmetics. PMID:25013740

  16. Structure and properties of porous ceramics obtained from aluminum hydroxide

    NASA Astrophysics Data System (ADS)

    Levkov, R.; Kulkov, S.

    2016-08-01

    In this paper the study of porous ceramics obtained from aluminum hydroxide with gibbsite modification is presented. The dependence of porosity and mechanical characteristics of the material sintered at different temperatures was studied. It was shown that compressive strength of alumina ceramics increases by 40 times with decreasing the pore volume from 65 to 15%. It was shown that aluminum hydroxide may be used for pore formation and pore volume in the sintered ceramics can be controlled by varying the aluminum hydroxide concentration and sintering temperature. Based on these results one can conclude that the obtained structure is very close to inorganic bone matrix and can be used as promising material for bone implants production.

  17. Carbide coated fibers in graphite-aluminum composites

    NASA Technical Reports Server (NTRS)

    Imprescia, R. J.; Levinson, L. S.; Reiswig, R. D.; Wallace, T. C.; Williams, J. M.

    1975-01-01

    The study of protective-coupling layers of refractory metal carbides on the graphite fibers prior to their incorporation into composites is presented. Such layers should be directly wettable by liquid aluminum and should act as diffusion barriers to prevent the formation of aluminum carbide. Chemical vapor deposition was used to uniformly deposit thin, smooth, continuous coats of ZrC on the carbon fibers of tows derived from both rayon and polyacrylonitrile. A wet chemical coating of the fibers, followed by high-temperature treatment, was used, and showed promise as an alternative coating method. Experiments were performed to demonstrate the ability of aluminum alloys to wet carbide surfaces. Titanium carbide, zirconium carbide and carbide-coated graphite surfaces were successfully wetted. Results indicate that initial attempts to wet surfaces of ZrC-coated carbon fibers appear successful.

  18. Casting Characteristics of Aluminum Die Casting Alloys

    SciTech Connect

    Makhlouf M. Makhlouf; Diran Apelian

    2002-02-05

    The research program investigates the casting characteristics of selected aluminum die casting alloys. Specifically, the alloys' tendencies towards die soldering and sludge formation, and the alloys' fluidity and machinability are evaluated. It was found that: When the Fe and Mn contents of the alloy are low; caution has to be taken against possible die soldering. When the alloy has a high sludge factor, particularly a high level of Fe, measures must be taken to prevent the formation of large hardspots. For this kind of alloy, the Fe content should be kept at its lowest allowable level and the Mn content should be at its highest possible level. If there are problems in die filling, measures other than changing the alloy chemistry need to be considered first. In terms of alloy chemistry, the elements that form high temperature compounds must be kept at their lowest allowable levels. The alloys should not have machining problems when appropriate machining techniques and machining parameters are used.

  19. 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.

  20. A Person-Centered Intervention in an International Peace Conference.

    ERIC Educational Resources Information Center

    Hughes, Marvalene Styles

    1988-01-01

    Notes that social scientists are exploring macro applications of human behavior theory to peace interventions. Provides an overview of an international intervention conducted by Carl R. Rogers and his colleagues. Describes the format of the Central American Challenge, an international conference conducted in Rust, Austria; conference participants;…

  1. Bridging Cultures with a Parent-Teacher Conference.

    ERIC Educational Resources Information Center

    Quiroz, Blanca; Greenfield, Patricia M.; Altchech, Marie

    1999-01-01

    Recent Latino immigrants may not realize that their children will be asked to relinquish collectivist values in pursuit of educational achievement. Finding child-led parent-teacher conferences incompatible with Latino values, a teacher training with the "Bridging Cultures Project" developed a less-threatening group-conference format. (10…

  2. Guide for Planning a High School Environmental Action Conference.

    ERIC Educational Resources Information Center

    Wanless, Angie, Comp.; And Others

    The purpose of this manual is to provide guidelines and suggestions for people organizing an environmental action conference for high school students. The format and planning suggestions are based on the methods used for a conference organized by the Wisconsin Center for Environmental Education in 1991. The bulk of the manual provides structure…

  3. 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.

  4. A Virtual Aluminum Reduction Cell

    NASA Astrophysics Data System (ADS)

    Zhang, Hongliang; Zhou, Chenn Q.; Wu, Bing; Li, Jie

    2013-11-01

    The most important component in the aluminum industry is the aluminum reduction cell; it has received considerable interests and resources to conduct research to improve its productivity and energy efficiency. The current study focused on the integration of numerical simulation data and virtual reality technology to create a scientifically and practically realistic virtual aluminum reduction cell by presenting complex cell structures and physical-chemical phenomena. The multiphysical field simulation models were first built and solved in ANSYS software (ANSYS Inc., Canonsburg, PA, USA). Then, the methodology of combining the simulation results with virtual reality was introduced, and a virtual aluminum reduction cell was created. The demonstration showed that a computer-based world could be created in which people who are not analysis experts can see the detailed cell structure in a context that they can understand easily. With the application of the virtual aluminum reduction cell, even people who are familiar with aluminum reduction cell operations can gain insights that make it possible to understand the root causes of observed problems and plan design changes in much less time.

  5. Abnormal behavior of silica doped with small amounts of aluminum

    PubMed Central

    Liu, Jinling; Wang, Yiguang; An, Linan

    2016-01-01

    Silica is the most abundant mineral in the crust of the Earth. It has been demonstrated that the aluminum concentration in silica plays a key role in determining many properties of silica-based components. Although the alumina-silica system has been intensely studied, the effect of very small amounts of aluminum on the structure and properties of silica remains unclear. We report results of first principles calculations showing that small amounts of aluminum could be metastable when located in the center of Si-O rings without breaking the silica network. In contrast, higher aluminum contents will result in the destruction of the Si-O bonds, leading to the formation of triclusters and a 4-, 5-, and 6-fold Al-O coordination, as observed in previous studies. Based on the silica structure obtained through geometric optimization, the properties of silica doped with small amounts of aluminum were calculated. The results can account for many ‘abnormal’ phenomena experimentally observed. The results benefit most areas such as geosciences, microelectronics, glass industry, and ceramic materials. PMID:27752133

  6. 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.

  7. Nanopore gradients on porous aluminum oxide generated by nonuniform anodization of aluminum.

    PubMed

    Kant, Krishna; Low, Suet P; Marshal, Asif; Shapter, Joseph G; Losic, Dusan

    2010-12-01

    A method for surface engineering of structural gradients with nanopore topography using the self-ordering process based on electrochemical anodization of aluminum is described. A distinct anodization condition with an asymmetrically distributed electric field at the electrolyte/aluminum interface is created by nonparallel arrangement between electrodes (tilted by 45°) in an electrochemical cell. The anodic aluminum oxide (AAO) porous surfaces with ordered nanopore structures with gradual and continuous change of pore diameters from 80 to 300 nm across an area of 0.5-1 cm were fabricated by this anodization using two common electrolytes, oxalic acid (0.3 M) and phosphoric acid (0.3 M). The formation of pore gradients of AAO is explained by asymmetric and gradual distribution of the current density and temperature variation generated on the surface of Al during the anodization process. Optical and wetting gradients of prepared pore structures were confirmed by reflective interferometric spectroscopy and contact angle measurements showing the ability of this method to generate porous surfaces with multifunctional gradients (structural, optical, wetting). The study of influence of pore structures on cell growth using the culture of neuroblastoma cells reveals biological relevance of nanopore gradients and the potential to be applied as the platform for spatially controllable cell growth and cell differentiation.

  8. NATO conference on space plasmas

    NASA Astrophysics Data System (ADS)

    Winckler, J. R.

    During the week of April 21-26, 1981, a group of research physicists with a special interest in artificial particle beams as applied to space plasma studies met at a conference site at Geilo, in the mountains of central Norway. Major support was provided by NATO, and the meeting was the first of a new series known as NATO Advanced Research Institutes. The session format somewhat resembled the recent Chapman conferences held at Yosemite National Park. Sessions were held each morning, Tuesday through Saturday, and after a lunch and recreational break, continued in the afternoon and early evening, up to dinner hour. The attendance was limited to about 65 persons, who were encouraged to stay together for the entire conference period. The unique character of the meeting was the result of current interest in this very specialized topic, the international attendance, and the excellent accommodations at the Vestilia Høyfjellshotell. The conferees assembled in Oslo and traveled together by train on Monday, April 20, arriving at Geilo in about 4 hours. The fact that most participants remained for the entire week and the fact that the rather relaxed pace of the meeting gave ample time for discussion and interchange of ideas contributed much to its success.

  9. 76 FR 64083 - Reliability Technical Conference; Notice of Technical Conference

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-17

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Reliability Technical Conference; Notice of Technical Conference Take notice that the Federal Energy Regulatory Commission will hold a Technical Conference on Tuesday, November...

  10. 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.

  11. 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.

  12. Reduction of Oxidative Melt Loss of Aluminum and Its Alloys

    SciTech Connect

    Dr. Subodh K. Das; Shridas Ningileri

    2006-03-17

    This project led to an improved understanding of the mechanisms of dross formation. The microstructural evolution in industrial dross samples was determined. Results suggested that dross that forms in layers with structure and composition determined by the local magnesium concentration alone. This finding is supported by fundamental studies of molten metal surfaces. X-ray photoelectron spectroscopy data revealed that only magnesium segregates to the molten aluminum alloy surface and reacts to form a growing oxide layer. X-ray diffraction techniques that were using to investigate an oxidizing molten aluminum alloy surface confirmed for the first time that magnesium oxide is the initial crystalline phase that forms during metal oxidation. The analytical techniques developed in this project are now available to investigate other molten metal surfaces. Based on the improved understanding of dross initiation, formation and growth, technology was developed to minimize melt loss. The concept is based on covering the molten metal surface with a reusable physical barrier. Tests in a laboratory-scale reverberatory furnace confirmed the results of bench-scale tests. The main highlights of the work done include: A clear understanding of the kinetics of dross formation and the effect of different alloying elements on dross formation was obtained. It was determined that the dross evolves in similar ways regardless of the aluminum alloy being melted and the results showed that amorphous aluminum nitride forms first, followed by amorphous magnesium oxide and crystalline magnesium oxide in all alloys that contain magnesium. Evaluation of the molten aluminum alloy surface during melting and holding indicated that magnesium oxide is the first crystalline phase to form during oxidation of a clean aluminum alloy surface. Based on dross evaluation and melt tests it became clear that the major contributing factor to aluminum alloy dross was in the alloys with Mg content. Mg was

  13. 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.

  14. Assessing the health risks of aluminum.

    PubMed

    Orme, J; Ohanian, E V

    1990-03-01

    Aluminum is a ubiquitous substance with over 4,000 uses. Aluminum, as aluminum sulfate, is commonly used in the United States as a coagulant in the treatment of drinking water. For many years aluminum was not considered to be toxic to humans. However, reports associating aluminum with several skeletal and neurological disorders in humans suggest that exposure to aluminum may pose a health hazard. In 1983 the US Environmental Protection Agency (EPA) announced plans to regulate a number of substances, including aluminum, in drinking water. Aluminum was considered because of its occurrence and apparent toxicity. Upon further evaluation of the health effects data the EPA proposed not to regulate aluminum as a result of the uncertainty of the toxicity of ingested aluminum. Putative causal associations between aluminum exposure and neurological disorders such as Alzheimer's disease have yet to be substantiated. Although several issues regarding the toxicity of ingested aluminum are unresolved, aluminum has been specified in the 1986 Amendments to the Safe Drinking Water Act, as one of 83 substances in drinking water to be regulated by 1989. Additional data are needed before the potential risk of aluminum can be assessed; therefore the EPA has deferred possible regulation until 1991. PMID:24202565

  15. Terbium photoluminescence in yttrium aluminum garnet xerogels

    SciTech Connect

    Maliarevich, G. K.; Gaponenko, N. V. Mudryi, A. V.; Drozdov, Yu. N.; Stepikhova, M. V.; Stepanova, E. A.

    2009-02-15

    Based on a colloidal solution containing terbium, yttrium, and aluminum metal ions, a powder was synthesized and films of terbium-doped yttrium aluminum garnet Tb{sub 0.15}Y{sub 2.85}Al{sub 5}O{sub 12} were grown on single-crystal silicon and porous anodic alumina. Annealing of the sample in a temperature range from 200-1100 deg. C results in an increase in the photoluminescence intensity in the wavelength range from 480-640 nm, which is caused by Tb{sup 3+} ion intra-atomic transitions {sup 5}D{sub 4}{sup {yields}}{sup 7}F{sub j} (j = 3, 4, 5, 6). Annealing at 900 deg. C and higher temperatures gives rise to low-intensity photoluminescence bands in the region of 667 and 681 nm, which correspond to transitions {sup 5}D{sub 4}{sup {yields}}{sup 7}F{sub 0}, {sup 5}D{sub 4}{sup {yields}}{sup 7}F{sub 1}, and room-temperature Stark term splitting, which suggests the existence of a crystalline environment of Tb{sup 3+} ions. The FWHM of spectral lines in the region of 543 nm decreases from {approx}10 to {approx}(2-3) nm as the xerogel annealing temperature is increased from 700 to 900 deg. C and higher. Three bands with maxima at 280, 330, and 376 nm, which correspond to Tb{sup 3+} ion transitions {sup 7}F{sub 6}{sup {yields}}{sup 5}I{sub 8}, {sup 5}L{sub 6}, {sup 5}G{sub 6}, {sup 5}D{sub 3}, are observed in the photoluminescence excitation spectra of the studied structures for the emission wavelength at 543 nm. X-ray diffraction detected the formation of a crystalline phase for a terbium-doped yttrium aluminum garnet powder after annealing at 1100 deg. C.

  16. Shuttle redesigned solid rocket motor aluminum oxide investigations

    NASA Astrophysics Data System (ADS)

    Blomshield, Fred S.; Kraeutle, Karl J.; Stalnaker, Richard A.

    1994-10-01

    During the launch of STS-54, a 15 psi pressure blip was observed in the ballistic pressure trace of one of the two Space Shuttle Redesigned Solid Rocket Motors (RSRM). One possible scenario for the observed pressure increase deals with aluminum oxide slag formation in the RSRM. The purpose of this investigation was to examine changes which may have occurred in the aluminum oxide formation in shuttle solid propellant due to changes in the ammonium perchlorate. Aluminum oxide formation from three propellants, all having the same formulation, but containing ammonium perchlorate from different manufacturers, will be compared. Three methods have been used to look for possible differences among the propellants. The first method was to examine window bomb movies of the propellants burning at 100, 300 and 600 psia. The motor operating pressure during the pressure blip was around 600 psia. The second method used small samples of propellant which were fired in a combustion bomb which quenched the burning aluminum particles soon after they left the propellant surface. The bomb was fired in both argon and Nitrogen atmospheres at various pressures. Products from this device were examined by optical microscopy. The third method used larger propellant samples fired into a particle collection device which allowed the aluminum to react and combust more completely. This device was pressurized with Nitrogen to motor operating pressures. The collected products were subdivided into size fractions by screening and sedimentation and analyzed optically with an optical microscope. The results from all three methods indicate very small changes in the size distribution of combustion products.

  17. Shuttle Redesigned Solid Rocket Motor aluminum oxide investigations

    NASA Astrophysics Data System (ADS)

    Blomshield, Fred S.; Kraeutle, Karl J.; Stalnaker, Richard A.

    1994-10-01

    During the launch of STS-54, a 15 psi pressure blip was observed in the ballistic pressure trace of one of the two Space Shuttle Redesigned Solid Rocket Motors (RSRM). One possible scenario for the observed pressure increase deals with aluminum oxide slag formation in the RSRM. The purpose of this investigation was to examine changes which may have occurred in the aluminum oxide formation in shuttle solid propellant due to changes in the ammonium perchlorate. Aluminum oxide formation from three propellants, all having the same formulation, but containing ammonium perchlorate from different manufacturers, will be compared. Three methods have been used to look for possible differences among the propellants. The first method was to examine window bomb movies of the propellants burning at 100, 300 and 600 psia. The motor operating pressure during the pressure blip was around 600 psia. The second method used small samples of propellant which were fired in a combustion bomb which quenched the burning aluminum particles soon after they left the propellant surface. The bomb was fired in both argon and Nitrogen atmospheres at various pressures. Products from this device were examined by optical microscopy. The third method used larger propellant samples fired into a particle collection device which allowed the aluminum to react and combust more completely. This device was pressurized with Nitrogen to motor operating pressures. The collected products were subdivided into size fractions by screening and sedimentation and analyzed optically with an optical microscope. the results from all three methods indicate very small changes in the size distribution of combustion products.

  18. Association mapping provides insights into the origin and the fine structure of the sorghum aluminum tolerance locus, AltSB

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Root damage caused by aluminum (Al) toxicity is a major cause of grain yield reduction on acid soils, which are prevalent in tropical and subtropical regions of the world where food security is most tenuous. In sorghum, Al tolerance is conferred by SbMATE, an Al-activated root citrate efflux transpo...

  19. Proceedings of the 21st annual offshore technology conference. Volume 1

    SciTech Connect

    Not Available

    1989-01-01

    This book contains the proceedings of a conference on offshore technology. Topics covered include: underwater wet welding of higher strength offshore steels; the proposed extended-reach drilling project; North Sea experience with aluminum drillpipe; and load transfer mechanism to offshore jackets during pile driving.

  20. Aluminum-dependent regulation of intracellular silicon in the aquatic invertebrate Lymnaea stagnalis

    PubMed Central

    Desouky, Mahmoud; Jugdaohsingh, Ravin; McCrohan, Catherine R.; White, Keith N.; Powell, Jonathan J.

    2002-01-01

    Silicon is essential for some plants, diatoms, and sponges but, in higher animals, its endogenous regulation has not been demonstrated. Silicate ions may be natural ligands for aluminum and here we show that, in the freshwater snail (Lymnaea stagnalis), intracellular silicon seems specifically up-regulated in response to sublethal aluminum exposure. X-ray microanalysis showed that exposure of snails to low levels of aluminum led to its accumulation in lysosomal granules, accompanied by marked up-regulation of silicon. Increased lysosomal levels of silicon were a specific response to aluminum because cadmium and zinc had no such effect. Furthermore, intra-lysosomal sulfur from metallothionein and other sulfur-containing ligands was increased after exposure to cadmium and zinc but not aluminum. To ensure that these findings indicated a specific in vivo response, and not ex vivo formation of hydroxy-aluminosilicates (HAS) from added aluminum (555 μg/liter) and water-borne silicon (43 μg/liter), two further studies were undertaken. In a ligand competition assay the lability of aluminum (527 μg/liter) was completely unaffected by the presence of silicon (46 μg/liter), suggesting the absence of HAS. In addition, exogenous silicon (6.5 mg/liter), added to the water column to promote formation of HAS, caused a decrease in lysosomal aluminum accumulation, showing that uptake of HAS would not explain the loading of aluminum into lysosomal granules. These findings, and arguments on the stability, lability, and kinetics of aluminum–silicate interactions, suggest that a silicon-specific mechanism exists for the in vivo detoxification of aluminum, which provides regulatory evidence of silicon in a multicellular organism. PMID:11891333

  1. Literacy and the Hearing Impaired Conference (Washington, D.C., May 18-20, 1989). [Proceedings.

    ERIC Educational Resources Information Center

    Center for Systems and Program Development, Inc., Washington, DC.

    This document presents conference materials and five conference papers on literacy and the hearing impaired. Preceding the papers, a section of general information provides an introduction, conference format information, and a commentary by Michael Rodda. Recommendations from the work groups and an executive summary are then presented.…

  2. District Leadership Conference Planner.

    ERIC Educational Resources Information Center

    Washington State Coordinating Council for Occupational Education, Olympia.

    This manual provides usable guidelines and planning forms and materials for planning district leadership conferences, which were designed and initiated in Washington State to meet the problems in student enrollment and, consequently, Distributive Education Clubs of America membership. The conferences have become a useful means to increase…

  3. [Conference Time Kit.

    ERIC Educational Resources Information Center

    National School Public Relations Association, Washington, DC.

    This multimedia kit, for use with and by teachers from kindergarten through the upper elementary grades, consists of four components: 1) a filmstrip for teachers; 2) the 1970 edition of a handbook, "Conference Time for Teachers and Parents"; 3) a filmstrip for parents; 4) a supporting parent information leaflet "How To Confer Successfully with…

  4. [Kweichow planned parenthood conference].

    PubMed

    1978-12-15

    On December 5th the Kweichow Provincial Planned Parenthood Leadership Group held its 1st conference to discuss the problems of planned parenthood in the province. Miao Chun-ting, deputy secretary of the provincial CCP committee and head of the provincial planned parenthood leadership group, presided over the conference.

  5. From Conference to Journal

    ERIC Educational Resources Information Center

    McCartney, Robert; Tenenberg, Josh

    2008-01-01

    Revising and extending conference articles for journal publication benefits both authors and readers. The new articles are more complete, and benefit from peer review, feedback from conference presentation, and greater editorial consistency. For those articles that are appropriate, we encourage authors to do this, and present two examples of such…

  6. The Conference in Retrospect.

    ERIC Educational Resources Information Center

    Gardner, Marjorie H.

    1982-01-01

    Presents an overview of the 6th International Conference on Chemical Education held at the University of Maryland (August 9-14, 1981), focusing on such organizational activities as roster building, people activating, innovative publishing, resolution and recommendation drafting, conference infrastructure and managerial mode, hospitality center,…

  7. The Learning Conference

    ERIC Educational Resources Information Center

    Ravn, Ib

    2007-01-01

    Purpose: The purpose of this paper is to call attention to the fact that conferences for professionals rely on massive one-way communication and hence produce little learning for delegates--and to introduce an alternative, the "learning conference", that involves delegates in fun and productive learning processes. Design/methodology/approach: A…

  8. ASE Annual Conference 2010

    ERIC Educational Resources Information Center

    McCune, Roger

    2010-01-01

    In this article, the author describes the ASE Annual Conference 2010 which was held at Nottingham after a gap of 22 years. As always, the main conference was preceded by International Day, an important event for science educators from across the world. There were two strands to the programme: (1) "What works for me?"--sharing new ideas and tried…

  9. Lyndon Johnson's Press Conferences.

    ERIC Educational Resources Information Center

    Cooper, Stephen

    Because President Lyndon Johnson understood well the publicity value of the American news media, he sought to exploit them. He saw reporters as "torch bearers" for his programs and policies and used the presidential press conference chiefly for promotional purposes. Although he met with reporters often, his press conferences were usually…

  10. ICCK Conference Final Report

    SciTech Connect

    Green, William H.

    2013-05-28

    The 7th International Conference on Chemical Kinetics (ICCK) was held July 10-14, 2011, at Massachusetts Institute of Technology (MIT), in Cambridge, MA, hosted by Prof. William H. Green of MIT's Chemical Engineering department. This cross-disciplinary meeting highlighted the importance of fundamental understanding of elementary reactions to the full range of chemical investigations. The specific conference focus was on elementary-step kinetics in both the gas phase and in condensed phase. The meeting provided a unique opportunity to discuss how the same reactive species and reaction motifs manifest under very different reaction conditions (e.g. atmospheric, aqueous, combustion, plasma, in nonaqueous solvents, on surfaces.). The conference featured special sessions on new/improved experimental techniques, improved models and data analysis for interpreting complicated kinetics, computational kinetics (especially rate estimates for large kinetic models), and a panel discussion on how the community should document/archive kinetic data. In the past, this conference had been limited to homogeneous gas-phase and liquid-phase systems. This conference included studies of heterogeneous kinetics which provide rate constants for, or insight into, elementary reaction steps. This Grant from DOE BES covered about half of the subsidies we provided to students and postdocs who attended the conference, by charging them reduced-rate registration fees. The complete list of subsidies provided are listed in Table 1 below. This DOE funding was essential to making the conference affordable to graduate students, and indeed the attendance at this conference was higher than at previous conferences in this series. Donations made by companies provided additional subsidies, leveraging the DOE funding. The conference was very effective in educating graduate students and important in fostering scientific interactions, particularly between scientists studying gas phase and liquid phase kinetics

  11. Parent-led conferences as sites of medical work.

    PubMed

    Dimond, Rebecca

    2014-11-01

    Conferences are novel sites for understanding medical work. Through describing styles of presentation that take place at conferences attended by patients and parents, this article highlights how clinicians on stage present ordinary and extraordinary aspects of medicine. Attention is drawn to the reaction of the parents in the audience. The power of the presenter to direct proceedings highlights the potential vulnerability of the audience. The relationship between clinician on stage and parents in the audience reflects the clinical relationship between doctor and patient. But through identifying insiders and outsiders, the conference setting also enables new relationships and collective identities to be formed. Drawing on an ethnographic study of rare disease conferences, this article extends understanding of medical work by identifying how conferences offer new ways of witnessing the clinical gaze, the doctor-patient relationship and the formation and enactment of a conference community. PMID:24677337

  12. Aluminum industry applications for OTEC

    SciTech Connect

    Jones, M.S.; Leshaw, D.; Sathyanarayana, K.; Sprouse, A.M.; Thiagarajan, V.

    1980-12-01

    The objective of the program is to study the integration issues which must be resolved to realize the market potential of ocean thermal energy conversion (OTEC) power for the aluminum industry. The study established, as a baseline, an OTEC plant with an electrical output of 100 MWe which would power an aluminum reduction plant. The reduction plant would have a nominal annual output of about 60,000 metric tons of aluminum metal. Three modes of operation were studied, viz: 1. A reduction plant on shore and a floating OTEC power plant moored offshore supplying energy by cable. 2. A reduction plant on shore and a floating OTEC power plant at sea supplying energy by means of an ''energy bridge.'' 3. A floating reduction plant on the same platform as the OTEC power plant. For the floating OTEC/aluminum plantship, three reduction processes were examined. 1. The conventional Hall process with prebaked anodes. 2. The drained cathode Hall cell process. 3. The aluminum chloride reduction process.

  13. 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.

  14. Aluminum enhances inflammation and decreases mucosal healing in experimental colitis in mice

    PubMed Central

    Pineton de Chambrun, G; Body-Malapel, M; Frey-Wagner, I; Djouina, M; Deknuydt, F; Atrott, K; Esquerre, N; Altare, F; Neut, C; Arrieta, M C; Kanneganti, T-D; Rogler, G; Colombel, J-F; Cortot, A; Desreumaux, P; Vignal, C

    2014-01-01

    The increasing incidence of inflammatory bowel diseases (IBDs) in developing countries has highlighted the critical role of environmental pollutants as causative factors in their pathophysiology. Despite its ubiquity and immune toxicity, the impact of aluminum in the gut is not known. This study aimed to evaluate the effects of environmentally relevant intoxication with aluminum in murine models of colitis and to explore the underlying mechanisms. Oral administration of aluminum worsened intestinal inflammation in mice with 2,4,6-trinitrobenzene sulfonic acid- and dextran sodium sulfate-induced colitis and chronic colitis in interleukin 10-negative (IL10−/−) mice. Aluminum increased the intensity and duration of macroscopic and histologic inflammation, colonic myeloperoxidase activity, inflammatory cytokines expression, and decreased the epithelial cell renewal compared with control animals. Under basal conditions, aluminum impaired intestinal barrier function. In vitro, aluminum induced granuloma formation and synergized with lipopolysaccharide to stimulate inflammatory cytokines expression by epithelial cells. Deleterious effects of aluminum on intestinal inflammation and mucosal repair strongly suggest that aluminum might be an environmental IBD risk factor. PMID:24129165

  15. The investigation on the stratification phenomenon of aluminum rear alloyed layer in silicon solar cells

    NASA Astrophysics Data System (ADS)

    Xi, Xi; Chen, Xiaojing; Zhang, Song; Shi, Zhengrong; Li, Guohua

    2015-06-01

    A stratification phenomenon of aluminum rear alloyed layer was found in the study of aluminum rear emitter N-type solar cells. It is related to the composition of the paste. The outer aluminum alloyed layer can be called as aluminum doped emitter, and it gives the contribution to the junction formation. The inner layer is only the Al/Si mixed layer. The aluminum atoms in this layer are not bonded with silicon atoms. This inner layer will ruin the quality of the rear junction. The shunt resistance, reverse current density and the junction electric leakage value are getting worse when the thickness of the inner layer increases. The thickness of the inner Al/Si mixed layer increases with the increasing of firing temperature, while the depth of the aluminum doped emitter almost does not change. From the analyses, the inner Al/Si mixed layer is redundant and deleterious. Only a single deep aluminum doped rear emitter is needed for N-type solar cells. The highest power conversion efficiency of 19.93% for aluminum rear emitter N-type cells without the stratification phenomenon has been obtained.

  16. A longitudinal study of rats chronically exposed to aluminum at human dietary levels.

    PubMed

    Walton, J R

    2007-01-22

    According to the World Health Organization, oral ingestion of aluminum additives is the main form of aluminum exposure for the general public. Aluminum salts are added to a range of commercially-prepared foods and beverages: to clarify drinking water, make salt free-pouring, color snack/dessert foods, and make baked goods rise. In the present study, six Wistar rats chronically consumed aluminum from 16 months of age to the conclusion of their lifespan (averaging 29.8 months) in an amount (1.5mg/kg bodyweight) equivalent to the high end of the total aluminum range ingested daily by humans living in contemporary urban society. The rats were memory-trained in a continuous rewarded alternation T-maze task and tested weekly from 5 months of age onwards. This longitudinal study compared their mean memory performances over 15 consecutive weeks during middle age (12-23 months) and old age (> or =24 months). Four out of six rats continued to perform the memory task in old age without significant deficit. The remaining two obtained significantly lower mean memory scores in old age than in middle age and exhibited soft signs associated with dementia. Their hippocampal neurons stained for aluminum, showing some but not all features of aluminum accumulation that occur in human hippocampal neurons. In view of evidenced linkages of aluminum with beta-amyloid plaque and neurofibrillary tangle formation in humans with Alzheimer's disease, the findings suggest this protocol is worth testing in larger groups of animals.

  17. Spray Forming Aluminum - Final Report (Phase II)

    SciTech Connect

    D. D. Leon

    1999-07-08

    The U.S. Department of Energy - Office of Industrial Technology (DOE) has an objective to increase energy efficient and enhance competitiveness of American metals industries. To support this objective, ALCOA Inc. entered into a cooperative program to develop spray forming technology for aluminum. This Phase II of the DOE Spray Forming Program would translate bench scale spray forming technology into a cost effective world class process for commercialization. Developments under DOE Cooperative Agreement No. DE-FC07-94ID13238 occurred during two time periods due to budgetary constraints; April 1994 through September 1996 and October 1997 and December 1998. During these periods, ALCOA Inc developed a linear spray forming nozzle and specific support processes capable of scale-up for commercial production of aluminum sheet alloy products. Emphasis was given to alloys 3003 and 6111, both being commercially significant alloys used in the automotive industry. The report reviews research performed in the following areas: Nozzel Development, Fabrication, Deposition, Metal Characterization, Computer Simulation and Economics. With the formation of a Holding Company, all intellectual property developed in Phases I and II of the Project have been documented under separate cover for licensing to domestic producers.

  18. Role of Exogenous Melatonin on Cell Proliferation and Oxidant/Antioxidant System in Aluminum-Induced Renal Toxicity.

    PubMed

    Karabulut-Bulan, Omur; Bayrak, Bertan Boran; Arda-Pirincci, Pelin; Sarikaya-Unal, Guner; Us, Huseyin; Yanardag, Refiye

    2015-11-01

    Aluminum has toxic potential on humans and animals when it accumulates in various tissues. It was shown in a number of studies that aluminum causes oxidative stress by free radical formation and lipid peroxidation in tissues and thus may cause damage in target organs. Although there are numerous studies investigating aluminum toxicity, biochemical mechanisms of the damage caused by aluminum have yet to be explained. Melatonin produced by pineal gland was shown to be an effective antioxidant. Since kidneys are target organs for aluminum accumulation and toxicity, we have studied the role of melatonin against aluminum-induced renal toxicity in rats. Wistar albino rats were divided into five groups. Group I served as control, and received only physiological saline; group II served as positive control for melatonin, and received ethanol and physiological saline; group III received melatonin (10 mg/kg); group IV received aluminum sulfate (5 mg/kg) and group V received aluminum sulfate and melatonin (in the same dose), injected three times a week for 1 month. Administration of aluminum caused degenerative changes in renal tissues, such as increase in metallothionein immunoreactivity and decrease in cell proliferation. Moreover, uric acid and lipid peroxidation levels and xanthine oxidase activity increased, while glutathione, catalase, superoxide dismutase, paraoxonase 1, glucose-6-phosphate dehydrogenase, and sodium potassium ATPase activities decreased. Administration of melatonin mostly prevented these symptoms. Results showed that melatonin is a potential beneficial agent for reducing damage in aluminum-induced renal toxicity.

  19. 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.

  20. 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.

  1. CONFERENCE NOTE: Conference on Precision Electromagnetic Measurements

    NASA Astrophysics Data System (ADS)

    1991-01-01

    The next Conference on Precision Electromagnetic Measurements (CPEM), will be held from 9 to 12 June 1992 at the Centre des Nouvelles Industries et Technologies (CNIT), La Défense, Paris, France. This conference, which is held every two years and whose importance and high level, confirmed by thirty years' experience, are recognized throughout the world, can be considered as a forum in which scientists, metrologists and professionals will have the opportunity to present and compare their research results on fundamental constants, standards and new techniques of precision measurement in the electromagnetic domain. Topics The following topics are regarded as the most appropriate for this conference: realization of units and fundamental constants d.c. a.c. and high voltage time and frequency radio-frequency and microwaves dielectrics, antennas, fields lasers, fibre optics advanced instrumentation, cryoelectronics. There will also be a session on international cooperation. Conference Language The conference language will be English. No translation will be provided. Organizers Société des Electriciens et des Electroniciens (SEE). Bureau National de Métrologie (BNM) Sponsors Institute of Electrical and Electronics Engineers (IEEE) Instrumentation & Measurement Society Union Radio Scientifique Internationale United States National Institute of Standards and Technology Centre National d'Etudes des Télécommunications Mouvement Français pour la Qualité, Section Métrologie Comité National Français de Radioélectricité Scientifique Contact Jean Zara, CPEM 92 publicity, Bureau National de Métrologie, 22, rue Monge, 75005 Paris Tel.: (33) 1 46 34 48 16, Fax: (33) 1 46 34 48 63

  2. 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.

  3. Formation Mechanism of CaO-SiO2-Al2O3-(MgO) Inclusions in Si-Mn-Killed Steel with Limited Aluminum Content During the Low Basicity Slag Refining

    NASA Astrophysics Data System (ADS)

    Wang, Kunpeng; Jiang, Min; Wang, Xinhua; Wang, Ying; Zhao, Haoqian; Cao, Zhanmin

    2016-02-01

    Pilot trails were carried out to study the formation mechanism of CaO-SiO2-Al2O3-(MgO) inclusions in tire cord steel. 48 samples were taken from 8 heats of liquid steel during secondary refining, which were subsequently examined by an automatic scanning electron microscope with energy dispersive spectrometer (SEM-EDS). Characteristics of thousands of oxide inclusions at different refining stages were obtained, including their compositions, sizes, morphologies, etc. Based on the obtained information of inclusions, details during formation of CaO-SiO2-Al2O3-(MgO) inclusions were revealed and a new mechanism was proposed, including their origin, formation, and evolution during the refining process. It was found that CaO-SiO2-Al2O3-(MgO) inclusions were initially originated from the CaO-SiO2-MnO-(MgO) inclusions, which were formed during BOF tapping by the coalescence between MnO-SiO2 deoxidation products and the emulsified slag particles because of violent flow of steel. This can be well confirmed by the evaluation of the formation thermodynamics of CaO-SiO2-MnO-(MgO) inclusions, which was proved very difficult to be produced by intrinsic reactions inside liquid steel. Because of chemical reactions between CaO-SiO2-MnO-(MgO) inclusions and molten steel, they were mainly changed into CaO-SiO2-MnO-Al2O3-(MgO) and partially into CaO-SiO2-Al2O3-(MgO), which may be detrimental to the cold drawing ability of coils. Based on this finding, improvements were made in industrial production during BOF tapping and secondary refining. The results indicated that such (CaO-SiO2)-based inclusions existed in conventional process were effectively decreased after the improvements.

  4. 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.

  5. Dissolution and Separation of Aluminum and Aluminosilicates

    DOE PAGES

    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

  6. 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.

  7. 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.

  8. 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.

  9. 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...

  10. 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.

  11. Diode laser welding of aluminum to steel

    SciTech Connect

    Santo, Loredana; Quadrini, Fabrizio; Trovalusci, Federica

    2011-05-04

    Laser welding of dissimilar materials was carried out by using a high power diode laser to join aluminum to steel in a butt-joint configuration. During testing, the laser scan rate was changed as well as the laser power: at low values of fluence (i.e. the ratio between laser power and scan rate), poor joining was observed; instead at high values of fluence, an excess in the material melting affected the joint integrity. Between these limiting values, a good aesthetics was obtained; further investigations were carried out by means of tensile tests and SEM analyses. Unfortunately, a brittle behavior was observed for all the joints and a maximum rupture stress about 40 MPa was measured. Apart from the formation of intermeltallic phases, poor mechanical performances also depended on the chosen joining configuration, particularly because of the thickness reduction of the seam in comparison with the base material.

  12. Alkaline oxide conversion coatings for aluminum alloys

    SciTech Connect

    Buchheit, R.G.

    1996-02-01

    Three related conversion coating methods are described that are based on film formation which occurs when aluminum alloys are exposed to alkaline Li salt solutions. Representative examples of the processing methods, resulting coating structure, composition and morphology are presented. The corrosion resistance of these coatings to aerated 0.5 M NaCl solution has been evaluated as a function of total processing time using electrochemical impedance spectroscopy (EIS). This evaluation shows that excellent corrosion resistance can be uniformly achieved using no more than 20 minutes of process time for 6061-T6. Using current methods a minimum of 80 minutes of process time is required to get marginally acceptable corrosion resistance for 2024-T3. Longer processing times are required to achieve uniformly good corrosion resistance.

  13. 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)

  14. 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.

  15. A Novel Method to Achieve Grain Refinement in Aluminum

    NASA Astrophysics Data System (ADS)

    Wang, Kui; Jiang, Haiyan; Wang, QuDong; Ye, Bing; Ding, Wenjiang

    2016-10-01

    A significant grain refinement of pure aluminum is achieved upon addition of TiCN nanoparticles (NPs). Unlike the conventional inoculation, NPs can induce the physical growth restriction through the formation of NP layer on the growing grain surface. An analytical model is developed to quantitatively account for the NP effects on grain growth. The NP-induced growth control can overcome the inherent limitations of inoculation and shed light on a potential method to achieve grain refinement.

  16. 47 CFR 1.248 - Prehearing conferences; hearing conferences.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Prehearing conferences; hearing conferences. 1.248 Section 1.248 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Hearing Proceedings Prehearing Procedures § 1.248 Prehearing conferences; hearing conferences. (a)...

  17. 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.

  18. Catalytic carbide formation at aluminium-carbon interfaces

    NASA Technical Reports Server (NTRS)

    Maruyama, B.; Rabenberg, L.; Ohuchi, F. S.

    1990-01-01

    X-ray photoelectron spectroscopy investigations of the reaction of several monolayer-thick films of aluminum with glassy carbon substrates are presented. The influence of molecular oxygen and water vapor on the rate of reaction is examined. It is concluded that water vapor catalyzed the formation of aluminum carbide from aluminum and carbon by forming active sites which weakened carbon-carbon bonds at the glassy carbon surface, thus assisting their cleavage. The rate of carbide formation for undosed and molecular oxygen-dosed examples was less as neither metallic aluminum nor oxygen-formed alumina could bond to the carbon atom with sufficient strength to dissociate it quickly.

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  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, 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...

  17. 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...

  18. 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...

  19. 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...

  20. Aircraft Engine Emissions. [conference

    NASA Technical Reports Server (NTRS)

    1977-01-01

    A conference on a aircraft engine emissions was held to present the results of recent and current work. Such diverse areas as components, controls, energy efficient engine designs, and noise and pollution reduction are discussed.

  1. Conference Summary Final Remarks

    NASA Astrophysics Data System (ADS)

    Greiner, Walter

    2007-05-01

    Finally we come to the last talk. The end of the Conference is near! I try to reflect on an interesting Conference, with many different - diverse - topics and 5 parallel afternoon sessions. How to solve this difficulty? I do it my way and present a selection of what I personally found interesting. I illustrate these topics with the help of slides which are borrowed from various speakers at the conference. There are outstanding problems, which will also find attention and interest if explained to non-nuclear physicists, common people. I will address four such topics which were were discussed at this conference: Heavy-Ion Cancer Therapy Extension of the Periodic Table - Superheavy Elements Nuclear Astrophysics Hot compressed elementary matter - Production - Phases

  2. DNA sequencing conference, 2

    SciTech Connect

    Cook-Deegan, R.M.; Venter, J.C.; Gilbert, W.; Mulligan, J.; Mansfield, B.K.

    1991-06-19

    This conference focused on DNA sequencing, genetic linkage mapping, physical mapping, informatics and bioethics. Several were used to study this sequencing and mapping. This article also discusses computer hardware and software aiding in the mapping of genes.

  3. Lunar & Planetary Science Conference.

    ERIC Educational Resources Information Center

    Warner, Jeffrey L.; And Others

    1982-01-01

    Summaries of different topics discussed at the Lunar and Planetary Science Conference are presented to provide updated information to nonplanetologists. Some topics include Venus, isotopes, chondrites, creation science, cosmic dust, cratering, moons and rings, igneous rocks, and lunar soil. (DC)

  4. 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.

  5. 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.

  6. Creep of laminated aluminum composites

    NASA Astrophysics Data System (ADS)

    Moore, W.; Davies, T. J.

    1980-08-01

    The creep behavior of a laminate system consisting of alternate layers of pure aluminum and SAP (sintered aluminum powder) sheet has been examined in the temperature range 323 to 473 K and in the stress range 35 to 68 MN m-2. It was observed that secondary creep strain in the laminates was greater than in elemental SAP; the secondary creep strain rate in laminates was lower than that in pure aluminum and the creep rate decreased with increasing fracture of SAP. A stress exponent ( n) value of ˜20 was observed for most of the laminates and was reasonably constant for 3, 5, 7, and 9 ply laminates and volume fractions V f ) in the range 0.3 < V f < 0.65. For higher volume fractions of SAP the mechanical behavior of the laminates was similar to that of SAP. The experimental activation energy for creep of 30.5 ± 5 Kcal mol-1 correlates well with that for self-diffusion in aluminum. Laminating induced appreciable ductility to the SAP.

  7. 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.

  8. 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.

  9. 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.

  10. Multiphoton processes: conference proceedings

    SciTech Connect

    Lambropoulos, P.; Smith, S.J.

    1984-01-01

    The chapters of this volume represent the invited papers delivered at the conference. They are arranged according to thermatic proximity beginning with atoms and continuing with molecules and surfaces. Section headings include multiphoton processes in atoms, field fluctuations and collisions in multiphoton process, and multiphoton processes in molecules and surfaces. Abstracts of individual items from the conference were prepared separately for the data base. (GHT)

  11. Conference scene: DGVS spring conference 2009.

    PubMed

    Kolligs, Frank Thomas

    2009-10-01

    The 3rd annual DGVS Spring Conference of the German Society for Gastroenterology (Deutsche Gesellschaft für Verdauungs- und Stoffwechselkrankheiten) was held at the Seminaris Campus Hotel in Berlin, Germany, on 8-9 May, 2009. The conference was organized by Roland Schmid and Matthias Ebert from the Technical University of Munich, Germany. The central theme of the meeting was 'translational gastrointestinal oncology: towards personalized medicine and individualized therapy'. The conference covered talks on markers for diagnosis, screening and surveillance of colorectal cancer, targets for molecular therapy, response prediction in clinical oncology, development and integration of molecular imaging in gastrointestinal oncology and translational research in clinical trial design. Owing to the broad array of topics and limitations of space, this article will focus on biomarkers, response prediction and the integration of biomarkers into clinical trials. Presentations mentioned in this summary were given by Matthias Ebert (Technical University of Munich, Germany), Esmeralda Heiden (Epigenomics, Berlin, Germany), Frank Kolligs (University of Munich, Germany), Florian Lordick (University of Heidelberg, Germany), Hans Jorgen Nielsen (University of Copenhagen, Denmark), Anke Reinacher-Schick (University of Bochum, Germany), Christoph Röcken (University of Berlin, Germany), Wolff Schmiegel (University of Bochum, Germany) and Thomas Seufferlein (University of Halle, Germany).

  12. Temperature Controlled Laser Joining of Aluminum to Galvanized Steel

    NASA Astrophysics Data System (ADS)

    Weller, Daniel; Simon, Jörg; Stritt, Peter; Weber, Rudolf; Graf, Thomas; Bezençon, Cyrille; Bassi, Corrado

    Reliable joining of 6000 series aluminum alloy to galvanized steel is a challenge for current manufacturing technologies. To control and limit the formation of brittle intermetallic phases, mixing of both metals in liquid state has to be avoided. It has been shown that laser weld-brazing is a possible process. Thereby the aluminum and zinc layer of the galvanized steel are molten and the steel remains solid during the process. In addition, to avoid zinc degassing, the aluminum melt bath temperature has to be below zinc boiling temperature of 907°C. To meet these requirements a temperature controlled laser process was developed, allowing to join the two materials without flux and filler material. The thickness of the intermetallic layer shows a dependency on the set temperature used to control the process. At optimum set temperature the thickness of intermetallic phases can be limited to about 5 μm. Tensile strengths of the joints of up to 75% of the aluminum base material were achieved.

  13. Aluminum-induced granulomas in a tattoo

    SciTech Connect

    McFadden, N.; Lyberg, T.; Hensten-Pettersen, A.

    1989-05-01

    A patient who developed localized, granulomatous reactions in a tattoo is described. With the use of scanning electron microscopy and energy dispersive x-ray microanalysis, both aluminum and titanium particles were found in the involved skin sections. Intradermal provocation testing with separate suspensions of aluminum and titanium induced a positive response only in the case of aluminum. Examination by scanning electron microscopy and energy dispersive x-ray microanalysis of the provoked response established aluminum as the only nonorganic element present in the test site tissue. This is the first report of confirmed aluminum-induced, delayed-hypersensitivity granulomas in a tattoo.

  14. Thermodynamics and kinetics of pack aluminide coating formation on IN-100

    NASA Technical Reports Server (NTRS)

    Levine, S. R.; Caves, R. M.

    1973-01-01

    An investigation of the effects of pack variables on the formation of aluminide coatings on nickel-base superalloy IN-100 was conducted. Also, the thermodynamics and kinetics of coating formation were analyzed. Observed coating weights were in good agreement with predictions made from the analysis. Pack temperature rather than pack aluminum activity controls the principal coating phase formed. In 1 weight percent aluminum packs, aluminum weight gains were related to the halide pack activator. Solid-state nickel diffusion controlled coating formation from sodium fluoride and chloride and ammonium fluoride activated packs. In other ammonium and sodium halide activated 1 weight percent aluminum packs, gaseous diffusion controlled coating formation.

  15. Antibody Engineering and Therapeutics Conference

    PubMed Central

    Almagro, Juan Carlos; Gilliland, Gary L; Scott, Jamie; Larrick, James W; Plückthun, Andreas; Veldman, Trudi; Adams, Gregory P; Parren, Paul WHI; Chester, Kerry A; Bradbury, Andrew; Reichert, Janice M; Huston, James S

    2013-01-01

    The Antibody Engineering and Therapeutics conference, which serves as the annual meeting of The Antibody Society, will be held in Huntington Beach, CA from Sunday December 8 through Thursday December 12, 2013. The scientific program will cover the full spectrum of challenges in antibody research and development, and provide updates on recent progress in areas from basic science through approval of antibody therapeutics. Keynote presentations will be given by Leroy Hood (Institute of System Biology), who will discuss a systems approach for studying disease that is enabled by emerging technology; Douglas Lauffenburger (Massachusetts Institute of Technology), who will discuss systems analysis of cell communication network dynamics for therapeutic biologics design; David Baker (University of Washington), who will describe computer-based design of smart protein therapeutics; and William Schief (The Scripps Research Institute), who will discuss epitope-focused immunogen design.   In this preview of the conference, the workshop and session chairs share their thoughts on what conference participants may learn in sessions on: (1) three-dimensional structure antibody modeling; (2) identifying clonal lineages from next-generation data sets of expressed VH gene sequences; (3) antibodies in cardiometabolic medicine; (4) the effects of antibody gene variation and usage on the antibody response; (5) directed evolution; (6) antibody pharmacokinetics, distribution and off-target toxicity; (7) use of knowledge-based design to guide development of complementarity-determining regions and epitopes to engineer or elicit the desired antibody; (8) optimizing antibody formats for immunotherapy; (9) antibodies in a complex environment; (10) polyclonal, oligoclonal and bispecific antibodies; (11) antibodies to watch in 2014; and (12) polyreactive antibodies and polyspecificity.

  16. 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.

  17. Adsorption of sodium dodecyl sulfate and sodium dodecyl phosphate on aluminum, studied by QCM-D, XPS, and AAS.

    PubMed

    Karlsson, Philip M; Palmqvist, Anders E C; Holmberg, Krister

    2008-12-01

    The adsorption of two anionic surfactants, sodium dodecyl sulfate (SDS) and sodium dodecyl phosphate (SDP), at surfaces of aluminum and aluminum oxide has been studied by means of atomic absorption spectrometry (AAS), X-ray photoelectron spectroscopy (XPS), and quartz crystal microbalance with dissipation monitoring (QCM-D). It was shown that more SDP than SDS binds to the surface and that SDP prevents dissolution of aluminum in water whereas SDS does not. This was not obvious, since the adsorption isotherms of the two surfactants to aluminum pigment powder are quite similar, as shown in an earlier work. The decreased aluminum dissolution with SDP compared to SDS was explained by the formation of a more compact protective layer with less permeability on the aluminum surface with SDP than with SDS. This is explained by differences in complexing ability between the surfactants and the aluminum pigment surface. While SDP is expected to form an inner-sphere complex with aluminum, leading to a lower accessibility of aluminum sites to water, SDS is likely to form a weaker outer-sphere complex.

  18. Aluminum Leaching of ''Archived'' Sludge from Tanks 8F, 11H, and 12H

    SciTech Connect

    FONDEUR, FERNANDOF.

    2004-03-12

    Aluminum can promote formation or dissolution of networks in hydroxide solid solutions. When present in large amounts it will act as a network former increasing both the viscosity and the surface tension of melts. This translates into poor free flow properties that affect pour rate of glass production in the Defense Waste Processing Facility (DWPF). To mitigate this situation, DWPF operations limit the amount of aluminum contained in sludge. This study investigated the leaching of aluminum compounds from archived sludge samples. The conclusions found boehmite present as the predominant aluminum compound in sludge from two tanks. We did not identify an aluminum compound in sludge from the third tank. We did not detect any amorphous aluminum hydroxide in the samples. The amount of goethite measured 4.2 percentage weight while hematite measured 3.7 percentage weight in Tank 11H sludge. The recommended recipe for removing gibbsite in sludge proved inefficient for digesting boehmite, removing less than 50 per cent of the compound within 48 hours. The recipe did remove boehmite when the test ran for 10 days (i.e., 7 more days than the recommended baseline leaching period). Additions of fluoride and phosphate to Tank 12H archived sludge did not improve the aluminum leaching efficiency of the baseline recipe.

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

    PubMed

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

    2014-01-01

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

  20. Thermal compatibility studies of unirradiated UMo alloys dispersed in aluminum

    NASA Astrophysics Data System (ADS)

    Lee, Don Bae; Kim, Ki Hwan; Kim, Chang Kyu

    1997-11-01

    The thermal compatibility of centrifugally atomized UMo alloys with aluminium has been studied. The results of the investigations show that the U-2 wt% Mo/aluminum dispersions increase in volume by 26% at 400°C after 2000 h. This large volume change is mainly due to the formation of voids and cracks resulting from nearly complete interdiffusion of UMo and aluminum. No significant dimensional changes occur in the U-10 wt% Mo/aluminum dispersions. Interdiffusion between U-10 wt% Mo and aluminum is found to be minimal. The different diffusion behavior is primarily due to the fact that U-10 wt% Mo particles are much more supersaturated with substitutional molybdenum than U-2 wt% Mo particles. The aluminum diffuses into the U-2 wt% Mo particles relatively rapidly along grain boundary with nearly pure uranium, forming UAl 3 almost fully throughout the 2000 h anneal, whereas the molybdenum supersaturated in the U-10 wt% Mo particles inhibits the diffusion of aluminum atoms. U-10 wt% Mo displays superior thermal compatibility with aluminum compared to U-2 wt% Mo.

  1. 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.

  2. 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.

  3. Tenth AMS Conference on Satellite Meteorology and Oceanography

    NASA Technical Reports Server (NTRS)

    Ferraro, R.; Colton, M.; Deblonde, G.; Jedlovec, G.; Lee, T.

    2000-01-01

    The American Meteorological Society held its Tenth Conference on Satellite Meteorology and Oceanography in conjunction with the 80th Annual Meeting in Long Beach, California. For the second consecutive conference, a format that consisted of primarily posters, complemented by invited theme oriented oral presentations, and panel discussions on various aspects on satellite remote sensing were utilized. Joint sessions were held with the Second Conference on Artificial Intelligence, the Eleventh Conference on Middle Atmosphere, and the Eleventh symposium on Global Change Studies. In total, there were 23 oral presentations, 170 poster presentations, and four panel discussions. Over 450 people representing a wide spectrum of the society attended one or more of the sessions in the five-day meeting. The program for the Tenth Conference on Satellite Meteorology and Oceanography can viewed in the October 1999 issue of the Bulletin.

  4. Laser Overlap Welding of Zinc-coated Steel on Aluminum Alloy

    NASA Astrophysics Data System (ADS)

    Kashani, Hamed Tasalloti; Kah, Paul; Martikainen, Jukka

    Local reinforcement of aluminum with laser welded patches of zinc-coated steel can effectively contribute to crashworthiness, durability and weight reduction of car body. However, the weld between Zn-coated steel and aluminum is commonly susceptible to defects such as spatter, cavity and crack. The vaporization of Zn is commonly known as the main source of instability in the weld pool and cavity formation, especially in a lap joint configuration. Cracks are mainly due to the brittle intermetallic compounds growing at the weld interface of aluminum and steel. This study provides a review on the main metallurgical and mechanical concerns regarding laser overlap welding of Zn-coated steel on Al-alloy and the methods used by researchers to avoid the weld defects related to the vaporization of Zn and the poor metallurgical compatibility between steel and aluminum.

  5. Passivation process for superfine aluminum powders obtained by electrical explosion of wires

    NASA Astrophysics Data System (ADS)

    Kwon, Young-Soon; Gromov, Alexander A.; Ilyin, Alexander P.; Rim, Geun-Hie

    2003-04-01

    The process of passivation of superfine aluminum powders (SFAPs) ( as≤100 nm), obtained with the electrical explosion of wires (EEW) method, has been studied. The passivation coatings of different nature (oxides, stearic acid and aluminum diboride) were covered on the particle surface. The process of passivation and analysis of passivated powders was studied by X-ray photoelectron spectroscopy (XPS), XRD, TEM, infrared spectroscopy (IR), mass spectrometry (MS), thermocouple method and bomb calorimetry. After the comprehensive testing of coatings, a model of stabilization of the superfine aluminum particles was suggested, explaining the anomalous high content of aluminum metal in the electroexplosive powders. The main characteristic of the model is a formation of charged structures, which prevent metal oxidation.

  6. Formation in the Classroom

    ERIC Educational Resources Information Center

    Glennon, Fred; Jacobsen, Douglas; Jacobsen, Rhonda Hustedt; Thatamanil, John J.; Porterfield, Amanda; Moore, Mary Elizabeth

    2011-01-01

    What is the relationship between the academic knowledge of the guild and the formation of students in the classroom? This Forum gathers four essays originally presented at a Special Topics Session at the 2009 conference of the American Academy of Religion (Atlanta, Georgia), with a brief introductory essay by Fred Glennon explaining the genesis of…

  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. Paired and interacting galaxies: Conference summary

    NASA Technical Reports Server (NTRS)

    Norman, Colin A.

    1990-01-01

    The author gives a summary of the conference proceedings. The conference began with the presentation of the basic data sets on pairs, groups, and interacting galaxies with the latter being further discussed with respect to both global properties and properties of the galactic nuclei. Then followed the theory, modelling and interpretation using analytic techniques, simulations and general modelling for spirals and ellipticals, starbursts and active galactic nuclei. Before the conference the author wrote down the three questions concerning pairs, groups and interacting galaxies that he hoped would be answered at the meeting: (1) How do they form, including the role of initial conditions, the importance of subclustering, the evolution of groups to compact groups, and the fate of compact groups; (2) How do they evolve, including issues such as relevant timescales, the role of halos and the problem of overmerging, the triggering and enhancement of star formation and activity in the galactic nuclei, and the relative importance of dwarf versus giant encounters; and (3) Are they important, including the frequency of pairs and interactions, whether merging and interactions are very important aspects of the life of a normal galaxy at formation, during its evolution, in forming bars, shells, rings, bulges, etc., and in the formation and evolution of active galaxies? Where possible he focuses on these three central issues in the summary.

  10. Final report on the Copper Mountain conference on multigrid methods

    SciTech Connect

    1997-10-01

    The Copper Mountain Conference on Multigrid Methods was held on April 6-11, 1997. It took the same format used in the previous Copper Mountain Conferences on Multigrid Method conferences. Over 87 mathematicians from all over the world attended the meeting. 56 half-hour talks on current research topics were presented. Talks with similar content were organized into sessions. Session topics included: fluids; domain decomposition; iterative methods; basics; adaptive methods; non-linear filtering; CFD; applications; transport; algebraic solvers; supercomputing; and student paper winners.

  11. 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.

  12. 78 FR 27963 - Reliability Technical Conference; Notice of Technical Conference

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-13

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Reliability Technical Conference; Notice of Technical Conference Take notice that the Federal Energy Regulatory Commission will hold a Technical Conference on Tuesday, July 9,...

  13. 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)

  14. Cranfield Conference on Information Retrieval.

    ERIC Educational Resources Information Center

    Kuo, Franklin F.

    The Third Cranfield Conference on Mechanised Information Storage and Retrieval Systems was held on 20-23 July 1971 in Cranfield, England. The report describes a number of the key papers presented at this conference. (Author)

  15. Planning a Women's Studies Conference.

    ERIC Educational Resources Information Center

    Saul, Jean Rannells

    1992-01-01

    Describes the organization and implementation of a women's studies conference. Discusses fund raising, identifying speakers, developing publicity, local arrangement efforts, and providing hospitality. Includes nine recommendations and a suggested conference timeline. (CFR)

  16. Experimenting with a Visible Copper-Aluminum Displacement Reaction in Agar Gel and Observing Copper Crystal Growth Patterns to Engage Student Interest and Inquiry

    ERIC Educational Resources Information Center

    Xu, Xinhua; Wu, Meifen; Wang, Xiaogang; Yang, Yangyiwei; Shi, Xiang; Wang, Guoping

    2016-01-01

    The reaction process of copper-aluminum displacement in agar gel was observed at the microscopic level with a stereomicroscope; pine-like branches of copper crystals growing from aluminum surface into gel at a constant rate were observed. Students were asked to make hypotheses on the pattern formation and design new research approaches to prove…

  17. Annual Conference Abstracts

    ERIC Educational Resources Information Center

    Engineering Education, 1976

    1976-01-01

    Presents the abstracts of 158 papers presented at the American Society for Engineering Education's annual conference at Knoxville, Tennessee, June 14-17, 1976. Included are engineering topics covering education, aerospace, agriculture, biomedicine, chemistry, computers, electricity, acoustics, environment, mechanics, and women. (SL)

  18. Government Quality Conference Proceedings

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The Government Quality Conference was an attempt to bring together executive organizations and senior individuals in the Federal Government that have a desire to improve productivity. It was designed to provide an exchange of ideas based on experience, and to encourage individual management initiatives to tap the capabilities of Federal employees.

  19. Conducting Telephone Conference IEPs

    ERIC Educational Resources Information Center

    Patterson, Philip Patrick; Petit, Constance; Williams, Shandelyn

    2007-01-01

    Synchronizing the availability of team members for Individual Education Plan (IEP) meetings can be a daunting task. Fortunately, the Individuals with Disabilities Education Improvement Act of 2004 permits alternative means of conducting such meetings. An example of an alternate means is a telephone conference, whereby parents communicate over the…

  20. International waste management conference

    SciTech Connect

    Not Available

    1989-01-01

    This book contains the proceedings of the international waste management conference. Topics covered include: Quality assurance in the OCR WM program; Leading the spirit of quality; Dept. of Energy hazardous waste remedial actions program; management of hazardous waste projects; and System management and quality assurance.

  1. REGIONAL CONFERENCE SUMMARIES, 1966.

    ERIC Educational Resources Information Center

    Bureau of Adult, Vocational, and Technical Education (DHEW/OE), Washington, DC. Div. of Vocational and Technical Education.

    AN AVERAGE OF 200 TEACHER EDUCATORS, STATE DIRECTORS, LAYMEN, AND REPRESENTATIVES OF VARIOUS AGENCIES ATTENDED EACH OF NINE REGIONAL CONFERENCES CONDUCTED THROUGHOUT THE UNITED STATES TO DISCUSS THE INFLUENCE OF SOCIAL AND ECONOMIC CHANGES AND PROBLEMS IN PLANNING AND CONDUCTING VOCATIONAL AND TECHNICAL EDUCATION PROGRAMS. MAJOR SPEECHES PRESENTED…

  2. Grammar! A Conference Report.

    ERIC Educational Resources Information Center

    King, Lid, Ed.; Boaks, Peter, Ed.

    Papers from a conference on the teaching of grammar, particularly in second language instruction, include: "Grammar: Acquisition and Use" (Richard Johnstone); "Grammar and Communication" (Brian Page); "Linguistic Progression and Increasing Independence" (Bernardette Holmes); "La grammaire? C'est du bricolage!" ("Grammar? That's Hardware!") (Barry…

  3. Annual Conference Abstracts

    ERIC Educational Resources Information Center

    Journal of Engineering Education, 1972

    1972-01-01

    Includes abstracts of papers presented at the 80th Annual Conference of the American Society for Engineering Education. The broad areas include aerospace, affiliate and associate member council, agricultural engineering, biomedical engineering, continuing engineering studies, chemical engineering, civil engineering, computers, cooperative…

  4. Metabolic Engineering X Conference

    SciTech Connect

    Flach, Evan

    2015-05-07

    The International Metabolic Engineering Society (IMES) and the Society for Biological Engineering (SBE), both technological communities of the American Institute of Chemical Engineers (AIChE), hosted the Metabolic Engineering X Conference (ME-X) on June 15-19, 2014 at the Westin Bayshore in Vancouver, British Columbia. It attracted 395 metabolic engineers from academia, industry and government from around the globe.

  5. APPA 2011 Conference Highlights

    ERIC Educational Resources Information Center

    Facilities Manager, 2011

    2011-01-01

    This article presents highlights of APPA conference that was held on July 16-18, 2011. The highlights feature photos of 2011-2012 board of directors, outgoing senior regional representatives to the board, meritorious service award, APPA fellow, president's recognition and gavel exchange, and diamond business partner award.

  6. Creating Better Satellite Conferences.

    ERIC Educational Resources Information Center

    Horner, Tommy

    1998-01-01

    Presents four ways to improve broadcasts of company satellite conferences, including creative site selection (using facilities at educational institutions rather than hotel rooms); creative programming (using graphics and other interruptions to break up lectures or speeches); creative crew selection; and creative downlink site activities (to…

  7. Conference on Censorship.

    ERIC Educational Resources Information Center

    Meltzer, Milton; And Others

    In this collection of seven speeches from the University of Missouri Conference on Censorship, writers focus on the various aspects of censorship. Speeches are by (1) Milton Meltzer, who lauds those writers who were forced to battle with censors; (2) Enid Olson, who explores the censorship problems faced by teachers and school librarians; (3)…

  8. The interparliamentary conference

    SciTech Connect

    Not Available

    1990-01-01

    The purpose of this conference was to provide a forum for exchange of information on environmental problems with global origins and consequences. The areas of major concern included the following: global climate change; deforestation and desertification; preservation of biological diversity; safeguarding oceans and water resources; population growth; destruction of the stratospheric ozone layer; and sustainable development.

  9. Microbicides 2006 conference

    PubMed Central

    Ramjee, Gita; Shattock, Robin; Delany, Sinead; McGowan, Ian; Morar, Neetha; Gottemoeller, Megan

    2006-01-01

    Current HIV/AIDS statistics show that women account for almost 60% of HIV infections in Sub-Saharan Africa. HIV prevention tools such as male and female condoms, abstinence and monogamy are not always feasible options for women due to various socio-economic and cultural factors. Microbicides are products designed to be inserted in the vagina or rectum prior to sex to prevent HIV acquisition. The biannual Microbicides conference took place in Cape Town, South Africa from 23–26 April 2006. The conference was held for the first time on the African continent, the region worst affected by the HIV/AIDS pandemic. The conference brought together a record number of 1,300 scientists, researchers, policy makers, healthcare workers, communities and advocates. The conference provided an opportunity for an update on microbicide research and development as well as discussions around key issues such as ethics, acceptability, access and community involvement. This report discusses the current status of microbicide research and development, encompassing basic and clinical science, social and behavioural science, and community mobilisation and advocacy activities. PMID:17038196

  10. 2002 NASPSA Conference Abstracts.

    ERIC Educational Resources Information Center

    Journal of Sport & Exercise Psychology, 2002

    2002-01-01

    Contains abstracts from the 2002 conference of the North American Society for the Psychology of Sport and Physical Activity. The publication is divided into three sections: the preconference workshop, "Effective Teaching Methods in the Classroom;" symposia (motor development, motor learning and control, and sport psychology); and free…

  11. On the Conference Circuit.

    ERIC Educational Resources Information Center

    Tyckoson, David A.

    1987-01-01

    Summarizes three conference presentations on the effects of the economic climate on academic libraries in Iowa. These presentations focused on the impact of austerity budgets on collection development, library services and personnel, and possible management approaches to retrenchment in these areas. (CLB)

  12. Conference on Navajo Orthography.

    ERIC Educational Resources Information Center

    Ohannessian, Sirarpi; And Others

    This report on the Conference on Navajo Orthography, held in Albuquerque, New Mexico on May 2-3, 1969 constitutes a summary of the discussion and decisions of a meeting which was convened by the Center for Applied Linguistics under contract with the Bureau of Indian Affairs to agree on an orthography for the Navajo language. The immediate purpose…

  13. Report on the Conference.

    ERIC Educational Resources Information Center

    Brown, Ralph S.

    1983-01-01

    The themes of the 1982 annual conference of the American Association of University Professors are outlined. They include the importance of planning, selective versus across-the-board retrenchment strategies, definitions and problems of financial exigency, program reduction, and affirmative action claims. (MSE)

  14. Open Mind Conference

    NASA Technical Reports Server (NTRS)

    King, Alexander H.

    1995-01-01

    Open Mind, The Association for the achievement of diversity in higher education, met in conference in Albuquerque, New Mexico, between October 16 and 18, 1992. A number of workgroups met to discuss the goals, structure, and generally evaluate the Association and its achievements. A summary of the workgroup sessions and their minutes are included.

  15. A Conference of Hope.

    ERIC Educational Resources Information Center

    American Printing House for the Blind, Louisville, KY. Dept. of Educational Research.

    Presented are the proceedings of the First Historic Helen Keller World Conference on Services to Deaf-Blind Youths and Adults, held in New York City in September, 1977 on the theme "The Deaf-Blind Person in the Community." Reports have the following titles and authors: "Definition, Demography, Causes and Prevention of Deaf-Blindness; Finding and…

  16. IATUL Conference 1985.

    ERIC Educational Resources Information Center

    Information Services and Use, 1985

    1985-01-01

    Summarizes presentations at conference on theme "The future of information resources for science and technology and role of libraries": industrial and commercial use of national, regional, and university resources; balance between public- and private-sector resources; local access in national and regional context; access to information in…

  17. 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.

  18. 40 CFR 63.5753 - How do I calculate the combined organic HAP content of aluminum wipedown solvents and aluminum...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... organic HAP content of aluminum wipedown solvents and aluminum recreational boat surface coatings? 63.5753...) National Emission Standards for Hazardous Air Pollutants for Boat Manufacturing Standards for Aluminum... aluminum wipedown solvents and aluminum recreational boat surface coatings? (a) Use equation 1 of...

  19. 40 CFR 180.1091 - Aluminum isopropoxide and aluminum secondary butoxide; exemption from the requirement of a...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Aluminum isopropoxide and aluminum... PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1091 Aluminum isopropoxide and aluminum secondary butoxide; exemption from the requirement of a tolerance. Aluminum isopropoxide (CAS Reg. No....

  20. 40 CFR 180.1091 - Aluminum isopropoxide and aluminum secondary butoxide; exemption from the requirement of a...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Aluminum isopropoxide and aluminum... PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1091 Aluminum isopropoxide and aluminum secondary butoxide; exemption from the requirement of a tolerance. Aluminum isopropoxide (CAS Reg. No....

  1. 40 CFR 180.1091 - Aluminum isopropoxide and aluminum secondary butoxide; exemption from the requirement of a...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Aluminum isopropoxide and aluminum... PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1091 Aluminum isopropoxide and aluminum secondary butoxide; exemption from the requirement of a tolerance. Aluminum isopropoxide (CAS Reg. No....

  2. 40 CFR 63.5753 - How do I calculate the combined organic HAP content of aluminum wipedown solvents and aluminum...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... organic HAP content of aluminum wipedown solvents and aluminum recreational boat surface coatings? 63.5753...) National Emission Standards for Hazardous Air Pollutants for Boat Manufacturing Standards for Aluminum... aluminum wipedown solvents and aluminum recreational boat surface coatings? (a) Use equation 1 of...

  3. 40 CFR 180.1091 - Aluminum isopropoxide and aluminum secondary butoxide; exemption from the requirement of a...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Aluminum isopropoxide and aluminum... PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1091 Aluminum isopropoxide and aluminum secondary butoxide; exemption from the requirement of a tolerance. Aluminum isopropoxide (CAS Reg. No....

  4. 40 CFR 63.5753 - How do I calculate the combined organic HAP content of aluminum wipedown solvents and aluminum...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... HAP content of aluminum wipedown solvents and aluminum recreational boat surface coatings? 63.5753...) National Emission Standards for Hazardous Air Pollutants for Boat Manufacturing Standards for Aluminum... aluminum wipedown solvents and aluminum recreational boat surface coatings? (a) Use equation 1 of...

  5. 40 CFR 180.1091 - Aluminum isopropoxide and aluminum secondary butoxide; exemption from the requirement of a...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Aluminum isopropoxide and aluminum... PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1091 Aluminum isopropoxide and aluminum secondary butoxide; exemption from the requirement of a tolerance. Aluminum isopropoxide (CAS Reg. No....

  6. ALA Conference 2009: Chicago Hope

    ERIC Educational Resources Information Center

    Berry, John N., III

    2009-01-01

    There is joy among those who have the funds to go to Chicago for the American Library Association (ALA) annual conference, July 9-15. Every librarian knows there is nothing better than a Chicago gathering, with the city's wonderful haunts, museums, restaurants, and fine memories of past conferences. The conference program covers nearly every…

  7. Summary: A Very Timely Conference

    NASA Astrophysics Data System (ADS)

    Wyse, Rosemary F. G.

    2012-04-01

    The conference poster includes a very apt phrase that describes a primary motivation for this conference: Time discovers truth. This aphorism, attributed to Seneca, was certainly affirmed by the many exciting talks and discussions at this conference, in both formal and informal settings.

  8. Potassium alum and aluminum sulfate micro-inclusions in polar ice from Dome Fuji, East Antarctica

    NASA Astrophysics Data System (ADS)

    Ohno, Hiroshi; Iizuka, Yoshinori; Horikawa, Shinichiro; Sakurai, Toshimitsu; Hondoh, Takeo; Motoyama, Hideaki

    2014-03-01

    Water-soluble trace constituents affect the physicochemical properties of polar ice. Their structural distribution provides important insights into the formation history of ice and inclusions. We report the first finding of KAl(SO4)2·12H2O (potassium alum) and Al2(SO4)3·nH2O (aluminum sulfate) micro-inclusions in the Dome Fuji ice core, East Antartica, using a micro-Raman technique. Eutectic temperatures of these water-soluble species determined using thermal analysis were -0.4 °C for potassium alum and -8.0 °C for aluminum sulfate. Although the formation process of the aluminum-bearing sulfates remains unclear, the occurrence of these salts largely depends on ice depth.

  9. Method of manufacturing aluminum sulfate from flue gas

    SciTech Connect

    Hauser, H.

    1981-10-20

    A continuous process for removing sulfur dioxide from flue gas is described. Sodium aluminate solution is reacted with sulfur dioxide to form sodium sulfite and aluminum hydroxy sulfite. These are separated and the aluminum hydroxy sulfite oxidized to aluminum sulfate.

  10. Aluminum silicide microparticles transformed from aluminum thin films by hypoeutectic interdiffusion

    PubMed Central

    2014-01-01

    Aluminum silicide microparticles with oxidized rough surfaces were formed on Si substrates through a spontaneous granulation process of Al films. This microparticle formation was caused by interdiffusion of Al and Si atoms at hypoeutectic temperatures of Al-Si systems, which was driven by compressive stress stored in Al films. The size, density, and the composition of the microparticles could be controlled by adjusting the annealing temperature, time, and the film thickness. High-density microparticles of a size around 10 μm and with an atomic ratio of Si/Al of approximately 0.8 were obtained when a 90-nm-thick Al film on Si substrate was annealed for 9 h at 550°C. The microparticle formation resulted in a rapid increase of the sheet resistance, which is a consequence of substantial consumption of Al film. This simple route to size- and composition-controllable microparticle formation may lay a foundation stone for the thermoelectric study on Al-Si alloy-based heterogeneous systems. PMID:24994964

  11. Investigations of Aluminum-Doped Self-Healing Zircaloy Surfaces in Context of Accident-Tolerant Fuel Cladding Research

    NASA Astrophysics Data System (ADS)

    Carr, James; Vasudevamurthy, Gokul; Snead, Lance; Hinderliter, Brian; Massey, Caleb

    2016-06-01

    We present here some important results investigating aluminum as an effective surface dopant for increased oxidation resistance of zircaloy nuclear fuel cladding. At first, the transport behavior of aluminum into reactor grade zircaloy was studied using simple diffusion couples at temperatures greater than 770 K. The experiments revealed the formation of tens of microns thick graded Zr-Al layers. The activation energy of aluminum in zircaloy was found to be ~175 kJ/mol (~1.8 eV), indicating the high mobility of aluminum in zircaloy. Subsequently, aluminum sputter-coated zircaloy coupons were heat-treated to achieve surface doping and form compositionally graded layers. These coupons were then tested in steam environments at 1073 and 1273 K. The microstructure of the as-fabricated and steam-corroded specimens was compared to those of pure zircaloy control specimens. Analysis of data revealed that aluminum effectively competed with zircaloy for oxygen up until 1073 K blocking oxygen penetration, with no traces of large scale spalling, indicating mechanically stable interfaces and surfaces. At the highest steam test temperatures, aluminum was observed to segregate from the Zr-Al alloy under layers and migrate to the surface forming discrete clusters. Although this is perceived as an extremely desirable phenomenon, in the current experiments, oxygen was observed to penetrate into the zirconium-rich under layers, which could be attributed to formation of surface defects such as cracks in the surface alumina layers.

  12. Speciation, stability, and coagulation mechanisms of hydroxyl aluminum clusters formed by PACl and alum: A critical review.

    PubMed

    Tang, Hongxiao; Xiao, Feng; Wang, Dongsheng

    2015-12-01

    The physicochemical property of coagulant species plays a significant role in the coagulation process. Recent progress on speciation, stability, and coagulation mechanisms of the hydroxyl aluminum clusters formed by PACl and alum has been critically reviewed. The complicated nature on species formation, stability, and transformation of various hydrolyzed aluminum clusters formed by PACl and Alum are discussed. Based on the aspects of spontaneous hydrolysis, forced hydrolysis, and dual-hydrolysis models, the special stability of aluminum clusters that results in various coagulation behaviors is compared with the traditional salts. The coagulation behavior of the hydroxyl aluminum clusters in terms of particle aggregation and restabilization, surface adsorption and coverage, microfloc formation and kinetics, modified DLVO simulation, and finally, the coagulation model is then analyzed in detail. It is indicative that the coagulation mechanism of inorganic coagulants can be understood better with the hydroxyl clusters being tailor-made.

  13. Synthesis, characterization, and evaluation of simple aluminum-based adsorbents for fluoride removal from drinking water.

    PubMed

    Du, Junyi; Sabatini, David A; Butler, Elizabeth C

    2014-04-01

    Simple aluminum (hydr)oxides and layered double hydroxides were synthesized using common chemicals and equipment by varying synthesis temperature, concentrations of extra sulfate and citrate, and metal oxide amendments. Aluminum (hydr)oxide samples were aged at either 25 or 200°C during synthesis and, in some cases, calcined at 600 °C. Despite yielding increased crystallinity and mineral phase changes, higher temperatures had a generally negative effect on fluoride adsorption. Addition of extra sulfate during synthesis of aluminum (hydr)oxides led to significantly higher fluoride adsorption capacity compared to aluminum (hydr)oxides prepared with extra citrate or no extra ligands. X-ray diffraction results suggest that extra sulfate led to the formation of both pseudoboehmite (γ-AlOOH) and basaluminite (Al4SO4(OH)10⋅4H2O) at 200 °C; energy dispersive X-ray spectroscopy confirmed the presence of sulfur in this solid. Treatment of aluminum (hydr)oxides with magnesium, manganese, and iron oxides did not significantly impact fluoride adsorption. While layered double hydroxides exhibited high maximum fluoride adsorption capacities, their adsorption capacities at dissolved fluoride concentrations close to the World Health Organization drinking water guideline of 1.5 mg L(-1) were much lower than those for the aluminum (hydr)oxides.

  14. The effect of aluminum hydroxide dissolution on the bleeding of aluminum lake dyes.

    PubMed

    Desai, A; Peck, G E; Lovell, J E; White, J L; Hem, S L

    1993-10-01

    The effect of pH on the bleeding of FD&C yellow No. 5 aluminum lake and FD&C red No. 40 aluminum lake was investigated. The pH-bleeding profiles corresponded to the pH-solubility profile of aluminum hydroxide. The similarity of the bleeding profiles of both lake dyes and the pH-solubility profile of aluminum hydroxide indicates that pH related bleeding, other than that occurring by competition with anions, is a result of dissolution of the aluminum hydroxide substrate. This dissolution is related to the properties of the substrate rather than to the structure of adsorbed dye.

  15. Surface complexation of aluminum on isolated fish gill cells

    SciTech Connect

    Wilkinson, K.J. Campbell, G.C.; Bertsch, P.M.; Jagoe, C.H.

    1993-06-01

    Cells from the gills of largemouth bass (Micropterus salmoides) were isolated and exposed to dilute solutions of Al, Al in the presence of fluoride, or Al plus dissolved organic matter (DOM) to determine the cells` metal binding potential in an acidic medium. Microelectrophoresis was employed to monitor the extent of aluminum sorption to cells in the presence of added ligand. In the absence of Al, the gill cells exhibit an appreciable negative charge; Al binding to the cell surface increases the electric potential at the shear plane and leads to a reduction in the cell`s (negative) electrophoretic mobility. In the presence of both Al and F, aluminum complexation at the gill surface is only marginally reduced; the formation of a mixed ligand complex, [F-Al-L-cell], is proposed to account for the observed results. The presence of such ternary complexes was subsequently verified by {sup 19}F nuclear magnetic resonance spectroscopy and by potentiometry. Addition of DOM increased the negative electrophoretic mobility of the isolated gill cells both in the presence and absence of aluminum (7.4 {mu}M). 45 refs., 7 figs., 1 tab.

  16. Thermoelectrical power analysis of precipitation in 6013 aluminum alloy

    SciTech Connect

    Abdala, M.R.W.S.; Garcia de Blas, J.C. Acselrad, O.

    2008-03-15

    The 6013 aluminum alloy was first developed for application in the aircraft industry and, more recently, as a replacement option for the use of the 6061 alloy in the automotive industry. The present work describes the evolution of the process of formation and dissolution of different kinds of precipitates in 6013 aluminum alloy, subjected to different conditions of heat treatment, using for this purpose measurements of thermoelectrical power, Vickers microhardness and differential scanning calorimeter (DSC). Although in the last years many works have been published on the use of thermoelectrical power (TEP) measurements for the analysis of precipitation process in traditional alloys such as 6061, there is still little information related to 6013 alloy. The results obtained are compared with a previous characterization work on the same alloy using transmission electron microscopy. It was observed that TEP measurements are very sensitive to precipitation phenomena in this alloy, and it has been found that there is an inverse relation between TEP and Vickers microhardness values, which allowed proposing a precipitation sequence for 6013 aluminum alloy.

  17. Energy Conferences and Symposia; (USA)

    SciTech Connect

    Osborne, J.H.; Simpson, W.F. Jr.

    1991-01-01

    Energy Conferences and Symposia, a monthly publication, was instituted to keep scientists, engineers, managers, and related energy professionals abreast of meetings sponsored by the Department of Energy (DOE) and by other technical associations. Announcements cover conference, symposia, workshops, congresses, and other formal meetings pertaining to DOE programmatic interests. Complete meeting information, including title, sponsor, and contact, is presented in the main section, which is arranged alphabetically by subject area. Within a subject, citations are sorted by beginning data of the meeting. New listings are indicated by a bullet after the conference number and DOE-sponsored conferences are indicated by a star. Two indexes are provided for cross referencing conference information. The Chronological Index lists conference titles by dates and gives the subject area where complete information they may be found. The Location Index is alphabetically sorted by the city where the conference will be held.

  18. INTERIOR VIEW OF ENTRANCE TO LABORATORY, SHOWING HANDHAMMERED ALUMINUM DOORS ...

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

    INTERIOR VIEW OF ENTRANCE TO LABORATORY, SHOWING HAND-HAMMERED ALUMINUM DOORS AND MARBLE. NOTE ALUMINUM LIGHT FIXTURE - Alcoa Research Laboratory, Freeport Road, New Kensington, Westmoreland County, PA

  19. METHOD FOR JOINING ALUMINUM TO STAINLESS STEEL

    DOEpatents

    Lemon, L.C.

    1960-05-24

    Aluminum may be joined to stainless steel without the use of flux by tinning the aluminum with a tin solder containing 1% silver and 1% lead, tinning the stainless steel with a 50% lead 50% tin solder, and then sweating the tinned surfaces together.

  20. SOLID STATE BONDING OF THORIUM WITH ALUMINUM

    DOEpatents

    Storchhelm, S.

    1959-12-01

    A method is described for bonding thorium and aluminum by placing clean surfaces of thorium and aluminum in contact with each other and hot pressing the metals together in a protective atmosphere at a temperature of about 375 to 575 deg C and at a pressure of at least 10 tsi to effect a bond.

  1. Aluminum low temperature smelting cell metal collection

    DOEpatents

    Beck, Theodore R.; Brown, Craig W.

    2002-07-16

    A method of producing aluminum in an electrolytic cell containing alumina dissolved in an electrolyte. The method comprises the steps of providing a molten salt electrolyte in an electrolytic cell having an anodic liner for containing the electrolyte, the liner having an anodic bottom and walls including at least one end wall extending upwardly from the anodic bottom, the anodic liner being substantially inert with respect to the molten electrolyte. A plurality of non-consumable anodes is provided and disposed vertically in the electrolyte. A plurality of cathodes is disposed vertically in the electrolyte in alternating relationship with the anodes. The anodes are electrically connected to the anodic liner. An electric current is passed through the anodic liner to the anodes, through the electrolyte to the cathodes, and aluminum is deposited on said cathodes. Oxygen bubbles are generated at the anodes and the anodic liner, the bubbles stirring the electrolyte. Molten aluminum is collected from the cathodes into a tubular member positioned underneath the cathodes. The tubular member is in liquid communication with each cathode to collect the molten aluminum therefrom while excluding electrolyte. Molten aluminum is delivered through the tubular member to a molten aluminum reservoir located substantially opposite the anodes and cathodes. The molten aluminum is collected from the cathodes and delivered to the reservoir while avoiding contact of the molten aluminum with the anodic bottom.

  2. Aluminum penetration and fracture of titanium diboride

    SciTech Connect

    Dorward, R.C.

    1982-01-01

    Relatively porous titanium diboride (/approximately equals/96% dense) is penetrated with aluminum metal when used as a cathode in aluminum reduction cells operating at 970/sup 0/C. Metal penetration changes the predominant fracture mode from transgranular to intergranular, and has potentially important ramifications on mechanical properties. 3 refs.

  3. RECOVERY OF METAL USING ALUMINUM DISPLACEMENT

    EPA Science Inventory

    The removal of typical metals (Cu, Pb, Sn, Ni) from printed circuit and metal finishing waste streams was evaluated using displacement with aluminum. he metal is recovered as non-hazardous metal particles and can be recycled by smelting. n acceptable aluminum metal configuration ...

  4. Recovery of aluminum from composite propellants

    NASA Technical Reports Server (NTRS)

    Shaw, G. C. (Inventor)

    1980-01-01

    Aluminum was recovered from solid rocket propellant containing a small amount of oxidizer by depolymerizing and dissolving propellant binders (containing functional or hydrolyzable groups in a solution of sodium methoxide) in an alcohol solvent optionally containing an aliphatic or aromatic hydrocarbon co-solvent. The solution was filtered to recover substantially all the aluminum in active form.

  5. Study of stress corrosion in aluminum alloys

    NASA Technical Reports Server (NTRS)

    Brummer, S. B.

    1967-01-01

    Mechanism of the stress corrosion cracking of high-strength aluminum alloys was investigated using electrochemical, mechanical, and electron microscopic techniques. The feasibility of detecting stress corrosion damage in fabricated aluminum alloy parts by nondestructive testing was investigated using ultrasonic surface waves and eddy currents.

  6. Electromagnetic bonding of plastics to aluminum

    NASA Technical Reports Server (NTRS)

    Sheppard, A. T.; Silbert, L.

    1980-01-01

    Electromagnetic curing is used to bond strain gage to aluminum tensile bar. Electromagnetic energy heats only plastic/metal interface by means of skin effect, preventing degradation of heat-treated aluminum. Process can be easily applied to other metals joined by high-temperature-curing plastic adhesives.

  7. Aluminum alloy and associated anode and battery

    SciTech Connect

    Tarcy, G.P.

    1990-08-21

    This patent describes an aluminum alloy. It comprises: eutectic amounts of at least two alloying elements selected from the group consisting of bismuth, cadmium, scandium, gallium, indium, lead, mercury, thallium, tin, and zinc with the balance being aluminum and the alloying elements being about 0.01 to 3.0 percent by weight of the alloy.

  8. Improved dual flow aluminum hydrogen peroxide battery

    NASA Astrophysics Data System (ADS)

    Marsh, Catherine; Licht, Stuart L.; Matthews, Donna

    1993-11-01

    A novel dual flow battery configuration is provided comprising an aqueous hydrogen peroxide catholyte, an aqueous anolyte, a porous solid electrocatalyst capable of reducing said hydrogen peroxide and separating said anolyte, and an aluminum anode positioned within said anolyte. Separation of catholyte and anolyte chambers prevents hydrogen peroxide poisoning of the aluminum anode.

  9. Improved dual flow aluminum hydrogen peroxide battery

    SciTech Connect

    Marsh, C.; Licht, S.L.; Matthews, D.

    1993-11-30

    A novel dual flow battery configuration is provided comprising an aqueous hydrogen peroxide catholyte, an aqueous anolyte, a porous solid electrocatalyst capable of reducing said hydrogen peroxide and separating said anolyte, and an aluminum anode positioned within said anolyte. Separation of catholyte and anolyte chambers prevents hydrogen peroxide poisoning of the aluminum anode.

  10. Laboratory Powder Metallurgy Makes Tough Aluminum Sheet

    NASA Technical Reports Server (NTRS)

    Royster, D. M.; Thomas, J. R.; Singleton, O. R.

    1993-01-01

    Aluminum alloy sheet exhibits high tensile and Kahn tear strengths. Rapid solidification of aluminum alloys in powder form and subsequent consolidation and fabrication processes used to tailor parts made of these alloys to satisfy such specific aerospace design requirements as high strength and toughness.

  11. Numerical simulation of the aluminum production

    NASA Astrophysics Data System (ADS)

    Popov, P. A.; Vabishchevich, P. N.

    2014-11-01

    Discusses the peculiarities of scientific and technical research problems based on mathematical modeling and computational experiment. Modern computer technology used in the modernization and development of new technologies of aluminum production. Marked features of mathematical models and software applications of multiphysics modeling of the aluminum electrolyzer.

  12. Wilson's disease; increased aluminum in liver.

    PubMed

    Yasui, M; Yoshimasu, F; Yase, Y; Uebayashi, Y

    1979-01-01

    Interaction of trace metal metabolism was studied in a patient with Wilson's dease. Atomic absorption analysis showed markedly increased urinary excretion of copper and aluminum and an increased aluminum content was found in the biopsied liver by neutron activation analysis. These findings suggest a complicated pathogenetic mechanism involving other metals besides copper in the Wilson's disease.

  13. Environmental effects on aluminum fracture

    NASA Technical Reports Server (NTRS)

    Schwartzberg, F. R.; Shepic, J. A.

    1976-01-01

    The sustained load stress corrosion cracking (SCC) threshold for aluminum alloy 214 was determined using smooth (sigma sub TH) and precracked (K sub ISCC) specimens, and cyclic load growth behavior in 3.5% NaCl salt solution was studied. The relationship between K sub ISCC and sigma sub TH was also studied. The work showed that 2124-T851 aluminum alloy in plate gage has a moderately high resistance to stress corrosion attack. Experimental results showed that no SCC occurred in the longitudinal and long transverse directions in any of the tests. Some SCC was found by smooth tests in the short transverse direction, and the data were confirmed by two test methods-sigma sub TH = 275 MN/sq m (40 ksi). No SCC was found from compact specimen tests in any direction: surface flaw and center notch specimens evaluated in the short transverse direction exhibited SCC. The data indicate that stress corrosion behavior is defect, size, and stress dependent, but not entirely in accordance with a stress intensity controlled mechanism.

  14. Mississippi Climate & Hydrology Conference

    SciTech Connect

    Lawford, R.; Huang, J.

    2002-05-01

    The GEWEX Continental International Project (GCIP), which started in 1995 and completed in 2001, held its grand finale conference in New Orleans, LA in May 2002. Participants at this conference along with the scientists funded through the GCIP program are invited to contribute a paper to a special issue of Journal of Geophysical Research (JGR). This special JGR issue (called GCIP3) will serve as the final report on scientific research conducted by GCIP investigators. Papers are solicited on the following topical areas, but are not limited to, (1) water energy budget studies; (2) warm season precipitation; (3) predictability and prediction system; (4) coupled land-atmosphere models; (5) climate and water resources applications. The research areas cover observations, modeling, process studies and water resources applications.

  15. IEEE conference record -- Abstracts

    SciTech Connect

    Not Available

    1994-01-01

    This conference covers the following areas: computational plasma physics; vacuum electronic; basic phenomena in fully ionized plasmas; plasma, electron, and ion sources; environmental/energy issues in plasma science; space plasmas; plasma processing; ball lightning/spherical plasma configurations; plasma processing; fast wave devices; magnetic fusion; basic phenomena in partially ionized plasma; dense plasma focus; plasma diagnostics; basic phenomena in weakly ionized gases; fast opening switches; MHD; fast z-pinches and x-ray lasers; intense ion and electron beams; laser-produced plasmas; microwave plasma interactions; EM and ETH launchers; solid state plasmas and switches; intense beam microwaves; and plasmas for lighting. Separate abstracts were prepared for 416 papers in this conference.

  16. Metabolic Engineering VII Conference

    SciTech Connect

    Kevin Korpics

    2012-12-04

    The aims of this Metabolic Engineering conference are to provide a forum for academic and industrial researchers in the field; to bring together the different scientific disciplines that contribute to the design, analysis and optimization of metabolic pathways; and to explore the role of Metabolic Engineering in the areas of health and sustainability. Presentations, both written and oral, panel discussions, and workshops will focus on both applications and techniques used for pathway engineering. Various applications including bioenergy, industrial chemicals and materials, drug targets, health, agriculture, and nutrition will be discussed. Workshops focused on technology development for mathematical and experimental techniques important for metabolic engineering applications will be held for more in depth discussion. This 2008 meeting will celebrate our conference tradition of high quality and relevance to both industrial and academic participants, with topics ranging from the frontiers of fundamental science to the practical aspects of metabolic engineering.

  17. NSI conference support

    NASA Technical Reports Server (NTRS)

    Aaron, Susan

    1991-01-01

    One of the many services NSI provides as an extension of customer/user support is to attend major scientific conferences. The conference effort provides NASA/OSSA scientists with many benefits: (1) scientist get to see NSI in action; they utilize the network to read email, and have recently begun to demonstrate their scientific research to their colleagues; (2) scientist get an opportunity to meet and interact with NSI Staff, which gives scientists a chance to get status on their requirements, ask about network status, get acquainted with our procedures, and learn about services; and (3) scientists are exposed to networking in a larger sense; particularly by knowing about other NASA groups who provide valuable scientific resources over the Internet.

  18. Diffuse parenchymal diseases associated with aluminum use and primary aluminum production.

    PubMed

    Taiwo, Oyebode A

    2014-05-01

    Aluminum use and primary aluminum production results in the generation of various particles, fumes, gases, and airborne materials with the potential for inducing a wide range of lung pathology. Nevertheless, the presence of diffuse parenchymal or interstitial lung disease related to these processes remains controversial. The relatively uncommon occurrence of interstitial lung diseases in aluminum-exposed workers--despite the extensive industrial use of aluminum--the potential for concurrent exposure to other fibrogenic fibers, and the previous use of inhaled aluminum powder for the prevention of silicosis without apparent adverse respiratory effects are some of the reasons for this continuing controversy. Specific aluminum-induced parenchymal diseases described in the literature, including existing evidence of interstitial lung diseases, associated with primary aluminum production are reviewed.

  19. Genome sequencing conference II

    SciTech Connect

    Not Available

    1990-01-01

    Genome Sequencing Conference 2 was held September 30 to October 30, 1990. 26 speaker abstracts and 33 poster presentations were included in the program report. New and improved methods for DNA sequencing and genetic mapping were presented. Many of the papers were concerned with accuracy and speed of acquisition of data with computers and automation playing an increasing role. Individual papers have been processed separately for inclusion on the database.

  20. Moldova. Historic regional conference.

    PubMed

    Moshin, V

    1995-05-01

    The Directorate of Maternal and Child Health and the Family Planning Association of Moldova organized a regional conference, which was held October 18-19, 1994, in Kishinev, Moldova, with the support of the United Nations Population Fund (UNFPA), the World Health Organization (WHO), and the International Planned Parenthood Federation (IPPF). The conference,"Problems of Family Planning in Eastern Europe," was attended by approximately 400 Moldovan delegates of governmental and nongovernmental organizations (NGOs), and by 25 delegates from Romania, Russia, Belarus, the Ukraine, and Georgia. The President of Moldova and the Ministry of Public Health of Moldova gave their approval. The main objectives of the conference were to inform the public about the recommendations of the ICPD, to analyze the status of women's reproductive health and family planning in Eastern Europe, and to find ways of implementing the ICPD Plan of Action. Major problems identified during the conference were: 1) the social and economic problems facing most families; 2) the high rate of morbidity and mortality; 3) the decrease in birth rate; 4) the increase in abortions; 5) the rising incidence of venereal disease; and 6) the absence of an effective family planning system. It was agreed that cooperation between governments and NGOs is essential in designing population programs for each country. The following goals were set: 1) to provide populations with sufficient contraceptives; 2) to actively promote family planning concepts through the mass media; 3) to train specialists and to open family planning offices and centers; 4) to introduce sex education in the curricula of Pedagogical Institutes; and 5) to create national and regional statistical and sociological databases on population issues.

  1. Porous Anodic Aluminum Oxide with Serrated Nanochannels

    NASA Astrophysics Data System (ADS)

    Li, Dongdong; Zhao, Liang; Lu, Jia G.

    2010-03-01

    Self-assembled nanoporous anodic aluminum oxide (AAO) membrane with straight channels has long been an important tool in synthesizing highly ordered and vertically aligned quasi-1D nanostructures for various applications. Recently shape-selective nanomaterials have been achieved using AAO as a template. It is envisioned that nanowires with multi-branches will significantly increase the active functional sites for applications as sensors, catalysts, chemical cells, etc. Here AAO membranes with serrated nanochannels have been successfully fabricated via a two-step annodization method. The serrated channels with periodic intervals are aligned at an angle of ˜25^circ along the stem channels. The formation of the serrated channels is attributed to the evolution of oxygen gas bubbles and the resulted plastic deformation in oxide membrane. In order to reveal the inside channel structure, Platinum are electrodeposited into the AAO template. The as-synthesized serrated Pt nanowires demonstrate a superior electrocatalytic activity. This is attributed to the enhanced electric field strength around serrated tips as shown in the electric field simulation by COMOSL. Moreover, hierarchical serrated/straight hybrid structures can be constructed using this simple and novel self assembly technique.

  2. Aluminum ion implantation under backfilling oxygen

    NASA Astrophysics Data System (ADS)

    Hausner, R. M.; Baumann, H.; Bethge, K.

    1996-06-01

    High dose ion implantation ( F ≥ 2 × 10 18 ions/cm 2) of 40 keV Al ions into stainless steel (AISI 321) under increased partial pressure of oxygen and oxygen compounds ( P ≥ 1 × 10 -8 hPa O 2, CO 2, N 2O) leads to the formation of a homogenous Al film on the sample surface due to a reduced self-sputtering yield of Al. The depth distribution of the implanted aluminum and the thickness of the Al film grown up on the sample were measured using the resonant nuclear reaction 27Al(p, γ) 28Si at 992 keV and by the (α, α) elastic backscattering at 3.05 MeV. The concentrations of the low- Z impurity oxygen and carbon were determined with the extremely strong resonances of the (α, α) elastic scattering under backward angles at 7.6 MeV for 16O and at 5.75 MeV for 12C. Furthermore the properties of the formed Al film were investigated by SEM, surface profile and microhardness measurements. The self-sputtering yield of Al was measured under normal vacuum conditions and under increased O 2 partial pressure, and the results were compared with the data obtained from calculations using the computer code T-DYN.

  3. APP expression, distribution and accumulation are altered by aluminum in a rodent model for Alzheimer's disease.

    PubMed

    Walton, J R; Wang, M-X

    2009-11-01

    Up-regulated expression of amyloid precursor protein (APP) occurs early in the cascade of events that leads to amyloid plaque formation in the human brain. APP gene up-regulation, mediated by activated NF-kappaB, is a response to stress from nM concentrations of aluminum ions, aluminum-disregulated iron ions, reactive-oxygen species, cytokines, and physical trauma. We examined in vivo effects of aluminum on APP in aged rats, obtained from previously-reported longitudinal studies, that chronically ingested aluminum in amounts equivalent to total dietary aluminum levels that Americans routinely ingest. These rats exhibited two outcomes: one group remained cognitively-intact, scoring as well on a memory-discrimination task in old age as in middle age. The other developed cognitive deterioration, obtaining significantly lower mean performance scores in old age than in middle age and exhibiting abnormal behaviors associated with dementia. We compared the expression, distribution and accumulation of APP in hippocampal and cortical tissue of these two rat groups. Compared to results from cognitively-intact rats, hippocampal and cortical tissue from the cognitively-deteriorated rats showed elevated APP gene expression, significantly more dense APP deposits in cytoplasm of neural cells, and APP-immunoreactive neurites that were swollen and varicose. This study shows aluminum routinely derived from chronic oral ingestion, that gradually accumulates in brain regions important for memory-processing, is sufficient to increase APP levels in neural cells of those regions. Aluminum may thus launch the cascade that results in the formation of amyloid plaques in human brain.

  4. Gating of Permanent Molds for ALuminum Casting

    SciTech Connect

    David Schwam; John F. Wallace; Tom Engle; Qingming Chang

    2004-03-30

    This report summarizes a two-year project, DE-FC07-01ID13983 that concerns the gating of aluminum castings in permanent molds. The main goal of the project is to improve the quality of aluminum castings produced in permanent molds. The approach taken was determine how the vertical type gating systems used for permanent mold castings can be designed to fill the mold cavity with a minimum of damage to the quality of the resulting casting. It is evident that somewhat different systems are preferred for different shapes and sizes of aluminum castings. The main problems caused by improper gating are entrained aluminum oxide films and entrapped gas. The project highlights the characteristic features of gating systems used in permanent mold aluminum foundries and recommends gating procedures designed to avoid common defects. The study also provides direct evidence on the filling pattern and heat flow behavior in permanent mold castings.

  5. Aluminum air battery for electric vehicle propulsion

    SciTech Connect

    Cooper, J.F.; Homsy, R.V.; Landrum, J.H.

    1980-01-01

    The status of aluminum-air battery development and the use of aluminum as a recyclable electrochemical fuel are discussed. The battery combines high specific energy (above 300 Wh/kg) and specific power (150 to 200 W/kg) with the capability of rapid refueling by addition of reactants. The objective is a commercially-feasible, general-purpose electric vehicle. Progress is reported in the scale-up of aluminum-air single cells to the automotive scale (0.1 m/sup 2/-anodes) and in the development of a hydrargillite crystallizer, which is required to control electrolyte composition. Major technical problems and development strategy are discussed. The total cost and energy required to produce aluminum, and projected consumption by electric vehicles indicates that the aluminum-air powered electric vehicle is potentially competitive with advanced automobiles using synthetic liquid fuels.

  6. Trends in the global aluminum fabrication industry

    NASA Astrophysics Data System (ADS)

    Das, Subodh; Yin, Weimin

    2007-02-01

    The aluminum fabrication industry has become more vital to the global economy as international aluminum consumption has grown steadily in the past decades. Using innovation, value, and sustainability, the aluminum industry is strengthening its position not only in traditional packaging and construction applications but also in the automotive and aerospace markets to become more competitive and to face challenges from other industries and higher industrial standards. The aluminum fabrication industry has experienced a significant geographical shift caused by rapid growth in emerging markets in countries such as Brazil, Russia, India, and China. Market growth and distribution will vary with different patterns of geography and social development; the aluminum industry must be part of the transformation and keep pace with market developments to benefit.

  7. 2004 Mutagenesis Gordon Conference

    SciTech Connect

    Dr. Sue Jinks-Robertson

    2005-09-16

    Mutations are genetic alterations that drive biological evolution and cause many, if not all, human diseases. Mutation originates via two distinct mechanisms: ''vertical'' variation is de novo change of one or few bases, whereas ''horizontal'' variation occurs by genetic recombination, which creates new mosaics of pre-existing sequences. The Mutagenesis Conference has traditionally focused on the generation of mutagenic intermediates during normal DNA synthesis or in response to environmental insults, as well as the diverse repair mechanisms that prevent the fixation of such intermediates as permanent mutations. While the 2004 Conference will continue to focus on the molecular mechanisms of mutagenesis, there will be increased emphasis on the biological consequences of mutations, both in terms of evolutionary processes and in terms of human disease. The meeting will open with two historical accounts of mutation research that recapitulate the intellectual framework of this field and thereby place the current research paradigms into perspective. The two introductory keynote lectures will be followed by sessions on: (1) mutagenic systems, (2) hypermutable sequences, (3) mechanisms of mutation, (4) mutation avoidance systems, (5) mutation in human hereditary and infectious diseases, (6) mutation rates in evolution and genotype-phenotype relationships, (7) ecology, mutagenesis and the modeling of evolution and (8) genetic diversity of the human population and models for human mutagenesis. The Conference will end with a synthesis of the meeting as the keynote closing lecture.

  8. Shell structures in aluminum nanocontacts at elevated temperatures

    PubMed Central

    2012-01-01

    Aluminum nanocontact conductance histograms are studied experimentally from room temperature up to near the bulk melting point. The dominant stable configurations for this metal show a very early crossover from shell structures at low wire diameters to ionic subshell structures at larger diameters. At these larger radii, the favorable structures are temperature-independent and consistent with those expected for ionic subshell (faceted) formations in face-centered cubic geometries. When approaching the bulk melting temperature, these local stability structures become less pronounced as shown by the vanishing conductance histogram peak structure. PMID:22325572

  9. Modeling possible structural transitions in aluminum and lead nanoclusters

    NASA Astrophysics Data System (ADS)

    Baidyshev, V. S.; Gafner, Yu. Ya.; Samsonov, V. M.; Bembel, A. G.

    2015-01-01

    The boundaries of thermal stability of the initial fcc phase in aluminum and lead clusters up to 3 nm in diameter have been investigated by the method of molecular dynamics using a modified tight-binding potential TB-SMA. It is shown that in small Al and Pb clusters the initial fcc phase passes into different structural modifications due the temperature factor. The polytype transition temperature has been found to approach the cluster melting temperature with an increase in the nanoparticle size. It is established that geometric "magic" numbers play an important role in the formation of structure of Al clusters (in contrast to Pb clusters).

  10. Shell structures in aluminum nanocontacts at elevated temperatures.

    PubMed

    Costa-Krämer, José Luis; León, Natalia; Guerrero, Carlo; Díaz, Marisel

    2012-01-01

    Aluminum nanocontact conductance histograms are studied experimentally from room temperature up to near the bulk melting point. The dominant stable configurations for this metal show a very early crossover from shell structures at low wire diameters to ionic subshell structures at larger diameters. At these larger radii, the favorable structures are temperature-independent and consistent with those expected for ionic subshell (faceted) formations in face-centered cubic geometries. When approaching the bulk melting temperature, these local stability structures become less pronounced as shown by the vanishing conductance histogram peak structure.

  11. Bioavailability and intestinal absorption of aluminum in rats: effects of aluminum compounds and some dietary constituents.

    PubMed

    Cunat, L; Lanhers, M C; Joyeux, M; Burnel, D

    2000-07-01

    In the present investigation, the deposition of aluminum in intestinal fragment and the appearance in blood were studied in a perfused rat intestine in situ for 1 h with several aluminum forms (16 mM). We observed that aluminum absorption was positively correlated with the theoretic affinity of aluminum and the functional groups of the chelating agent. The absorption of aluminum after ingestion of organic compounds is more important than after ingestion of mineral compounds, with the following order: Al citrate > Al tartrate, Al gluconate, Al lactate > Al glutamate, Al chloride, Al sulfate, Al nitrate. Absorption depends on the nature of the ligands associated with the Al3+ ion in the gastrointestinal fluid. The higher the aluminum retention in intestinal fragment, the lower the absorption and appearance in blood. However, the higher aluminum concentration is always in the jejunal fragment because of the influence of pH variation on this fragment. Another objective of the present study was to determine the influence of several parameters on aluminum citrate absorption: with or without 0.1 mmol dinitrophenol/L, with aluminum concentration from 3.2, 16, 32, and 48, to 64 mmol/L, media containing 0, 3, or 6 mmol Ca/L, with or without phosphorus or glucose. It is concluded that aluminum is absorbed from the gastrointestinal tract by (1) a paracellular energy independent and nonsaturable route, mainly used for high aluminum concentration, which is modified by extracellular calcium, and (2) a transcellular and saturable route, the aluminum level was not modified with enhancement of aluminum quantity in intestinal lumen. This pathway can be similar with calcium transfer through the intestine and is energy dependent because of a decrease of aluminum absorption that follows the removal of glucose and phosphorus.

  12. Development and evaluation of anode alloys for aluminum/air batteries: Final report

    SciTech Connect

    Macdonald, D.; Real, S.; Urquidi-Macdonald, M.

    1987-02-01

    Experimental and theoretical studies are reported on the development of aluminum alloys for alkaline aluminumair batteries. This work begins by analyzing the thermodyanmics of aluminum in LiOH, NaOH, and KOH solutions as a function of concentration (0 to 7 molkg alkali) and temperature (25 to 100)degree)C). The thermodynamic data define the conditions under which precipitation of Al(OH)/sub 3/ may occur but, more importantly for this study, they yield equilibrium potentials for various charge transfer reactions, including aluminum dissolution, Al(OH)/sub 3/ and A100H formation, AlH/sub 3/ formation, oxygen reduction, and hydrogen evoltuion. These data are used in our mechanistic analyses of aluminum electrodissolution. The findings of this work form the basis of a working model for the activation of aluminum alloy fuels for alkaline aluminumair batteries, in which activation is attributed to the oxidative dissolution of a protective layer of metallic alloying elements (principally gallium) from the surface at a voltage of )approximately)1.5 V (HgHgO). This model is now being used to design and prepare new high energy density anodes for Alair batteris. 29 refs., 87 figs., 39 tabs

  13. Characterization of the nitrogen split interstitial defect in wurtzite aluminum nitride using density functional theory

    SciTech Connect

    Szállás, A.; Szász, K.; Gali, A.

    2014-09-21

    We carried out Heyd-Scuseria-Ernzerhof hybrid density functional theory plane wave supercell calculations in wurtzite aluminum nitride in order to characterize the geometry, formation energies, transition levels, and hyperfine tensors of the nitrogen split interstitial defect. The calculated hyperfine tensors may provide useful fingerprint of this defect for electron paramagnetic resonance measurement.

  14. Orbital fabrication of aluminum foam and apparatus therefore

    NASA Technical Reports Server (NTRS)

    Tucker, Dennis S. (Inventor)

    2010-01-01

    A process for producing foamed aluminum in space comprising the steps of: heating aluminum until it is molten; applying the force of gravity to the molten aluminum; injecting gas into the molten aluminum to produce molten foamed aluminum; and allowing the molten foamed aluminum to cool to below melting temperature. The apparatus for carrying out this invention comprises: a furnace which rotates to simulate the force of gravity and heats the aluminum until it is molten; a door on the furnace, which is opened for charging the aluminum into the furnace, closed for processing and opened again for removal of the foamed aluminum; a gas injection apparatus for injecting gas into the molten aluminum within the furnace; and an extraction apparatus adjacent the door for removing the foamed aluminum from the furnace.

  15. PREFACE: Wake Conference 2015

    NASA Astrophysics Data System (ADS)

    Barney, Andrew; Nørkær Sørensen, Jens; Ivanell, Stefan

    2015-06-01

    The 44 papers in this volume constitute the proceedings of the 2015 Wake Conference, held in Visby on the island of Gotland in Sweden. It is the fourth time this conference has been held. The Wake Conference series started in Visby, where it was held in 2009 and 2011. In 2013 it took place in Copenhagen where it was combined with the International Conference on Offshore Wind Energy and Ocean Energy. In 2015 it is back where it started in Visby, where it takes place at Uppsala University Campus Gotland, June 9th-11th. The global yearly production of electrical energy by wind turbines has grown tremendously in the past decade and it now comprises more than 3% of the global electrical power consumption. Today the wind power industry has a global annual turnover of more than 50 billion USD and an annual average growth rate of more than 20%. State-of-the-art wind turbines have rotor diameters of up to 150 m and 8 MW installed capacity. These turbines are often placed in large wind farms that have a total production capacity corresponding to that of a nuclear power plant. In order to make a substantial impact on one of the most significant challenges of our time, global warming, the industry's growth has to continue for a decade or two yet. This in turn requires research into the physics of wind turbine wakes and wind farms. Modern wind turbines are today clustered in wind farms in which the turbines are fully or partially influenced by the wake of upstream turbines. As a consequence, the wake behind the wind turbines has a lower mean wind speed and an increased turbulence level, as compared to the undisturbed flow outside the farm. Hence, wake interaction results in decreased total production of power, caused by lower kinetic energy in the wind, and an increase in the turbulence intensity. Therefore, understanding the physical nature of the vortices and their dynamics in the wake of a turbine is important for the optimal design of a wind farm. This conference is aimed

  16. Architecture of conference control functions

    NASA Astrophysics Data System (ADS)

    Kausar, Nadia; Crowcroft, Jon

    1999-11-01

    Conference control is an integral part in many-to-many communications that is used to manage and co-ordinate multiple users in conferences. There are different types of conferences which require different types of control. Some of the features of conference control may be user invoked while others are for internal management of a conference. In recent years, ITU (International Telecommunication Union) and IETF (Internet Engineering Task Force) have standardized two main models of conferencing, each system providing a set of conference control functionalities that are not easily provided in the other one. This paper analyzes the main activities appropriate for different types of conferences and presents an architecture for conference control called GCCP (Generic Conference Control Protocol). GCCP interworks different types of conferencing and provides a set of conference control functions that can be invoked by users directly. As an example of interworking, interoperation of IETF's SIP and ITU's H.323 call control functions have been examined here. This paper shows that a careful analysis of a conferencing architecture can provide a set of control functions essential for any group communication model that can be extensible if needed.

  17. Pathways to a family of low-cost, high-performance, metal matrix composites based on aluminum diboride in aluminum

    NASA Astrophysics Data System (ADS)

    Hall, Aaron Christopher

    The continued development of a new family of metal matrix composites based on the in-situ formation of AlB2 flakes in liquid aluminum is described. First, a new synthesis technique for the preparation of high aspect ratio AlB2 is demonstrated. Borax and B2O 3 were reacted with molten aluminum to prepare high aspect ratio AlB 2. The focus then shifts to further understanding the Al-B alloy system. Work on the Al-B alloy system concentrated on the Al(L) + AlB 2 → Al(L) + AlB12 peritectic transformation and the growth of AlB2 in aluminum. The equilibrium peritectic transformation temperature was redetermined and found to be 950 +/- 5°C. The kinetics of the peritectic transformation were measured and reported for the first time. Cu, Fe, and Si additions were made to the alloy, and their effect on the peritectic reaction was investigated. All three elements shorten the time required for the peritectic reaction to occur. The effect of these three elements on flake growth was also investigated. They each caused a reduction in the size of growing AlB2 flakes. Finally two samples containing more than 30v% AlB2 in aluminum were prepared. Their properties were measured. The sample containing 40v% AlB2 exhibited a flexural strength of 200 MPa. The 35v% sample exhibited a flexural strength of 150 MPa. When the 35v% sample was tested in compression, it exhibited an ultimate strength close to 200 MPa. Its modulus varied from 200--300 GPa depending on the orientation of the loading axis with respect to the flake reinforcement.

  18. Aluminum concentrations in infant formulae.

    PubMed

    Simmer, K; Fudge, A; Teubner, J; James, S L

    1990-02-01

    The aluminum concentrations in breast milk and in 25 commercially available infant formulae were measured. The mean concentration in breast milk was 49 micrograms/L while concentrations in most of the humanized formulae were less than 500 micrograms/L. Higher concentrations were found in Nan, Prem Enfamil and the three soya formulae. We suggest that all formulae have the potential to be contaminated with aluminium, and to varying degrees in different batches. Until it is known whether aluminium toxicity occurs in normal infants fed these formulae, it seems reasonable to expect manufacturers to routinely measure aluminium and keep aluminium contamination to a minimum. This may be especially important for formula fed to infants with compromised gastrointestinal and renal systems.

  19. Oxidation dynamics of aluminum nanorods

    SciTech Connect

    Li, Ying; Kalia, Rajiv K.; Nakano, Aiichiro; Vashishta, Priya

    2015-02-23

    Aluminum nanorods (Al-NRs) are promising fuels for pyrotechnics due to the high contact areas with oxidizers, but their oxidation mechanisms are largely unknown. Here, reactive molecular dynamics simulations are performed to study thermally initiated burning of oxide-coated Al-NRs with different diameters (D = 26, 36, and 46 nm) in oxygen environment. We found that thinner Al-NRs burn faster due to the larger surface-to-volume ratio. The reaction initiates with the dissolution of the alumina shell into the molten Al core to generate heat. This is followed by the incorporation of environmental oxygen atoms into the resulting Al-rich shell, thereby accelerating the heat release. These results reveal an unexpectedly active role of the alumina shell as a “nanoreactor” for oxidation.

  20. Oxidation dynamics of aluminum nanorods

    NASA Astrophysics Data System (ADS)

    Li, Ying; Kalia, Rajiv K.; Nakano, Aiichiro; Vashishta, Priya

    2015-02-01

    Aluminum nanorods (Al-NRs) are promising fuels for pyrotechnics due to the high contact areas with oxidizers, but their oxidation mechanisms are largely unknown. Here, reactive molecular dynamics simulations are performed to study thermally initiated burning of oxide-coated Al-NRs with different diameters (D = 26, 36, and 46 nm) in oxygen environment. We found that thinner Al-NRs burn faster due to the larger surface-to-volume ratio. The reaction initiates with the dissolution of the alumina shell into the molten Al core to generate heat. This is followed by the incorporation of environmental oxygen atoms into the resulting Al-rich shell, thereby accelerating the heat release. These results reveal an unexpectedly active role of the alumina shell as a "nanoreactor" for oxidation.

  1. The Interviewer Interviewed and Other Background to ASE's Summer Celebration Conference

    ERIC Educational Resources Information Center

    Smith, Annette

    2013-01-01

    Experiment is at the heart of science and this was a consideration in the planning of an Association for Science Education (ASE) conference in the summer term that could be guided, but not controlled, by experience from the Annual Conference at New Year. Different formats for the exhibitions, lectures and practical presentations could all be tried…

  2. Oxidation kinetics of aluminum diboride

    NASA Astrophysics Data System (ADS)

    Whittaker, Michael L.; Sohn, H. Y.; Cutler, Raymond A.

    2013-11-01

    The oxidation characteristics of aluminum diboride (AlB2) and a physical mixture of its constituent elements (Al+2B) were studied in dry air and pure oxygen using thermal gravimetric analysis to obtain non-mechanistic kinetic parameters. Heating in air at a constant linear heating rate of 10 °C/min showed a marked difference between Al+2B and AlB2 in the onset of oxidation and final conversion fraction, with AlB2 beginning to oxidize at higher temperatures but reaching nearly complete conversion by 1500 °C. Kinetic parameters were obtained in both air and oxygen using a model-free isothermal method at temperatures between 500 and 1000 °C. Activation energies were found to decrease, in general, with increasing conversion for AlB2 and Al+2B in both air and oxygen. AlB2 exhibited O2-pressure-independent oxidation behavior at low conversions, while the activation energies of Al+2B were higher in O2 than in air. Differences in the composition and morphology between oxidized Al+2B and AlB2 suggested that Al2O3-B2O3 interactions slowed Al+2B oxidation by converting Al2O3 on aluminum particles into a Al4B2O9 shell, while the same Al4B2O9 developed a needle-like morphology in AlB2 that reduced oxygen diffusion distances and increased conversion. The model-free kinetic analysis was critical for interpreting the complex, multistep oxidation behavior for which a single mechanism could not be assigned. At low temperatures, moisture increased the oxidation rate of Al+2B and AlB2, but both appear to be resistant to oxidation in cool, dry environments.

  3. The biological speciation and toxicokinetics of aluminum.

    PubMed Central

    DeVoto, E; Yokel, R A

    1994-01-01

    This review discusses recent literature on the chemical and physiological factors that influence the absorption, distribution, and excretion of aluminum in mammals, with particular regard to gastrointestinal absorption and speciation in plasma. Humans encounter aluminum, a ubiquitous yet highly insoluble element in most forms, in foods, drinking water, and pharmaceuticals. Exposure also occurs by inhalation of dust and aerosols, particularly in occupational settings. Absorption from the gut depends largely on pH and the presence of complexing ligands, particularly carboxylic acids, with which the metal can form absorbable neutral aluminum species. Uremic animals and humans experience higher than normal body burdens of aluminum despite increased urinary clearance of the metal. In plasma, 80-90% of aluminum binds to transferrin, an iron-transport protein for which receptors exist in many tissue. The remaining fraction of plasma aluminum takes the form of small-molecule hydroxy species and small complexes with carboxylic acids, phosphate, and, to a much lesser degree, amino acids. Most of these species have not been observed in vivo but are predicted from equilibrium models derived from potentiometric methods and NMR investigations. These models predict that the major small-molecule aluminum species under plasma conditions are charged and hence unavailable for uptake into tissues. PMID:9738208

  4. Applied and Environmental Microbiology Gordon Research Conference

    SciTech Connect

    Wall, Judy D.

    2003-11-19

    The main objective of the Gordon Research Conference on Applied and Environmental Microbiology was to present and discuss new, fundamental research findings on microorganisms, their activities in the environment, their ecosystem-level effects, and their environmental or commercial applications. To accomplish this goal, knowledge of microbial diversity, interactions and population dynamics was required. The genomic basis of microbial processes, the cycling of naturally occurring and hazardous substances, and methodologies to assess the functional relationships of microorganisms in their habitats were essential for understanding the ecological consequences of microbial activities and the formulation of generalizing principles. In the last decade, molecular technology has revealed that microbial diversity is far more extensive than the limited view obtained from culturing procedures. Great advances in environmental microbiology have resulted from the development and application of molecular approaches to ecology and molecular evolution. A further surprise resulting from the application of these new tools is the blurring of the distinction between pathogenic traits versus those considered non-pathogenic. This year's conference addressed the issues of biodiversity, its development, and the impact of stress on gene selection and expression. In addition microbial metabolic versatility with toxins such as heavy metals, antibiotics, and organic pollutants were discussed. The nine session topics were (1) biodiversity and the bacterial species, (2) mechanisms of biodiversification, (3) biofilms in health and environment, (4) a genomic view of microbial response to stress, (5) microbial use of toxic metals, (6) microbial mineral formation and dissolution, (7) power and limitations of antimicrobials, (8) biodegradation of organic pollutants, and (9) astrobiology. The Conference had an international profile: the Conference Vice-Chair, Dr. Gerard Muyzer, was from The Nether lands

  5. Decontamination and reuse of ORGDP aluminum scrap

    SciTech Connect

    Compere, A.L.; Griffith, W.L.; Hayden, H.W.; Wilson, D.F.

    1996-12-01

    The Gaseous Diffusion Plants, or GDPs, have significant amounts of a number of metals, including nickel, aluminum, copper, and steel. Aluminum was used extensively throughout the GDPs because of its excellent strength to weight ratios and good resistance to corrosion by UF{sub 6}. This report is concerned with the recycle of aluminum stator and rotor blades from axial compressors. Most of the stator and rotor blades were made from 214-X aluminum casting alloy. Used compressor blades were contaminated with uranium both as a result of surface contamination and as an accumulation held in surface-connected voids inside of the blades. A variety of GDP studies were performed to evaluate the amounts of uranium retained in the blades; the volume, area, and location of voids in the blades; and connections between surface defects and voids. Based on experimental data on deposition, uranium content of the blades is 0.3%, or roughly 200 times the value expected from blade surface area. However, this value does correlate with estimated internal surface area and with lengthy deposition times. Based on a literature search, it appears that gaseous decontamination or melt refining using fluxes specific for uranium removal have the potential for removing internal contamination from aluminum blades. A melt refining process was used to recycle blades during the 1950s and 1960s. The process removed roughly one-third of the uranium from the blades. Blade cast from recycled aluminum appeared to perform as well as blades from virgin material. New melt refining and gaseous decontamination processes have been shown to provide substantially better decontamination of pure aluminum. If these techniques can be successfully adapted to treat aluminum 214-X alloy, internal and, possibly, external reuse of aluminum alloys may be possible.

  6. Form and stability of aluminum hydroxide complexes in dilute solution

    USGS Publications Warehouse

    Hem, John David; Roberson, Charles Elmer

    1967-01-01

    size and orderliness of the polymeric aggregates and was accompanied by a decrease in the pH of the solution. The kinetic experiments and stoichiometric data for solutions aged for long periods provided a means of determining activities of polymerized aluminum. From these values the solubility product for microcrystalline gibbsite was determined to be 2.24 x 10 -3, and its free energy of formation, -? 272.3 0.4 kcal per mole. Where polymerization was observed, the process did not stop with small polynuclear complexes containing a few aluminum ions, but proceeded with aging until macromolecules or colloidal-sized particles were formed.

  7. The formation of chondrules at high gas pressures in the solar nebula.

    PubMed

    Galy, A; Young, E D; Ash, R D; O'Nions, R K

    2000-12-01

    High-precision magnesium isotope measurements of whole chondrules from the Allende carbonaceous chondrite meteorite show that some aluminum-rich Allende chondrules formed at or near the time of formation of calcium-aluminum-rich inclusions and that some others formed later and incorporated precursors previously enriched in magnesium-26. Chondrule magnesium-25/magnesium-24 correlates with [magnesium]/[aluminum] and size, the aluminum-rich, smaller chondrules being the most enriched in the heavy isotopes of magnesium. These relations imply that high gas pressures prevailed during chondrule formation in the solar nebula.

  8. Fretting of Nickel-Chromium-Aluminum Alloys at Temperatures to 816 C

    NASA Technical Reports Server (NTRS)

    Bill, R. C.

    1974-01-01

    A series of four nickel-based alloys containing 10 percent and 20 percent chromium in combination with 2 percent and 5 percent aluminum were fretted in dry air at temperatures to 816 C. At all temperatures, the alloys showed far less fretting wear than did high-purity nickel. This was attributed to the formation of protective oxide films on the alloys, the result of the selective oxidation of the alloy constituents. Increasing the aluminum concentration reduced fretting wear at all temperatures. Increasing the chromium concentration from 10 percent to 20 percent resulted in decreased fretting wear at 23 and 540 C, but increased fretting wear at 650 and 816 C.

  9. The investigation of cerium as a cathodic inhibitor for aluminum-copper alloys

    SciTech Connect

    Aldykewicz, A.J. Jr.; Isaacs, H.S.; Davenport, A.J.

    1995-10-01

    In situ current density mapping, scanning electron microscopy , and energy dispersive spectroscopy were used to study the effects of cerium as a corrosion inhibitor for an aluminum copper alloy (Al 2024-T4) in chloride containing solutions. It was found that cerium inhibits corrosion of this alloy by reducing the rate of the cathodic reaction. This was due to the carried out on an aluminum/copper galvanic couple, which was used to simulate the electrochemical behavior of the copper containing intermetallics, showed that corrosion inhibition was associated with the formation of a Ce-rich film over the copper in agreement with that observed for the alloy.

  10. Intraneuronal aluminum accumulation in amyotrophic lateral sclerosis and Parkinsonism-dementia of Guam

    SciTech Connect

    Perl, D.P.; Gajdusek, D.C.; Garruto, R.M.; Yanagihara, R.T.; Gibbs, C.J.

    1982-09-10

    Scanning electron microscopy with energy-dispersive x-ray spectrometry was used to analyze the elemental content of neurofibrillary tangle (NFT)-bearing and NFT-free neurons within the Sommer's sector (H1 region) of the hippocampus in Guamanian Chamorros with amyotrophic lateral sclerosis and parkinsonism-dementia and in neurologically normal controls. Preliminary data indicate prominent accumulation of aluminum within the nuclear region and perikaryal cytoplasm of NFT-bearing hippocampal neurons, regardless of the underlying neurological diagnosis. These findings further extend the association between intraneuronal aluminum and NFT formation and support the hypothesis that environmental factors are related to the neurodegenerative changes seen in the Chamorro population.

  11. Rural Energy Conference Project

    SciTech Connect

    Dennis Witmer; Shannon Watson

    2008-12-31

    Alaska remains, even at the beginning of the 21st century, a place with many widely scattered, small, remote communities, well beyond the end of both the road system and the power grid. These communities have the highest energy costs of any place in the United States, despite the best efforts of the utilities that service them. This is due to the widespread dependence on diesel electric generators, which require small capital investments, but recent increases in crude oil prices have resulted in dramatic increases in the cost of power. In the enabling legislation for the Arctic Energy Office in 2001, specific inclusion was made for the study of ways of reducing the cost of electrical power in these remote communities. As part of this mandate, the University of Alaska has, in conjunction with the US Department of Energy, the Denali Commission and the Alaska Energy Authority, organized a series of rural energy conferences, held approximately every 18 months. The goal of these meeting was to bring together rural utility operators, rural community leaders, government agency representatives, equipment suppliers, and researchers from universities and national laboratories to discuss the current state of the art in rural power generation, to discuss current projects, including successes as well as near successes. Many of the conference presenters were from industry and not accustomed to writing technical papers, so the typical method of organizing a conference by requesting abstracts and publishing proceedings was not considered viable. Instead, the organizing committee solicited presentations from appropriate individuals, and requested that (if they were comfortable with computers) prepare Power point presentations that were collected and posted on the web. This has become a repository of many presentations, and may be the best single source of information about current projects in the state of Alaska.

  12. Aerospace Environmental Technology Conference

    NASA Technical Reports Server (NTRS)

    Whitaker, A. F. (Editor)

    1995-01-01

    The mandated elimination of CFC's, Halons, TCA, and other ozone depleting chemicals and specific hazardous materials has required changes and new developments in aerospace materials and processes. The aerospace industry has been involved for several years in providing product substitutions, redesigning entire production processes, and developing new materials that minimize or eliminate damage to the environment. These activities emphasize replacement cleaning solvents and their application verifications, compliant coatings including corrosion protection systems, and removal techniques, chemical propulsion effects on the environment, and the initiation of modifications to relevant processing and manufacturing specifications and standards. The Executive Summary of this Conference is published as NASA CP-3297.

  13. Networks Technology Conference

    NASA Technical Reports Server (NTRS)

    Tasaki, Keiji K. (Editor)

    1993-01-01

    The papers included in these proceedings represent the most interesting and current topics being pursued by personnel at GSFC's Networks Division and supporting contractors involved in Space, Ground, and Deep Space Network (DSN) technical work. Although 29 papers are represented in the proceedings, only 12 were presented at the conference because of space and time limitations. The proceedings are organized according to five principal technical areas of interest to the Networks Division: Project Management; Network Operations; Network Control, Scheduling, and Monitoring; Modeling and Simulation; and Telecommunications Engineering.

  14. Aspen Winter Conference Series

    SciTech Connect

    1999-01-01

    (B204) The meeting will bring together observers and theorists in a highly interactive format, to further connect the local and cosmological star formation communities. Forward looking talks, aimed at the other communities, will survey terminology, achievements, problems and aspirations. Discussion will focus on the definition of the key questions, how the different communities can help each other, and preparations for the incorporation of realistic star formation into cosmological simulations.

  15. Spray Rolling Aluminum Strip for Transportation Applications

    SciTech Connect

    Kevin M. McHugh; Y. Lin; Y. Zhou; E. J. Lavernia; J.-P. Delplanque; S. B. Johnson

    2005-02-01

    Spray rolling is a novel strip casting technology in which molten aluminum alloy is atomized and deposited into the roll gap of mill rolls to produce aluminum strip. A combined experimental/modeling approach has been followed in developing this technology with active participation from industry. The feasibility of this technology has been demonstrated at the laboratory scale and it is currently being scaled-up. This paper provides an overview of the process and compares the microstructure and properties of spray-rolled 2124 aluminum alloy with commercial ingot-processed material

  16. Electrically conductive containment vessel for molten aluminum

    DOEpatents

    Holcombe, C.E.; Scott, D.G.

    1984-06-25

    The present invention is directed to a containment vessel which is particularly useful in melting aluminum. The vessel of the present invention is a multilayered vessel characterized by being electrically conductive, essentially nonwettable by and nonreactive with molten aluminum. The vessel is formed by coating a tantalum substrate of a suitable configuration with a mixture of yttria and particulate metal 10 borides. The yttria in the coating inhibits the wetting of the coating while the boride particulate material provides the electrical conductivity through the vessel. The vessel of the present invention is particularly suitable for use in melting aluminum by ion bombardment.

  17. Cathode for aluminum producing electrolytic cell

    DOEpatents

    Brown, Craig W.

    2004-04-13

    A method of producing aluminum in an electrolytic cell comprising the steps of providing an anode in a cell, preferably a non-reactive anode, and also providing a cathode in the cell, the cathode comprised of a base material having low electrical conductivity reactive with molten aluminum to provide a highly electrically conductive layer on the base material. Electric current is passed from the anode to the cathode and alumina is reduced and aluminum is deposited at the cathode. The cathode base material is selected from boron carbide, and zirconium oxide.

  18. Electrically conductive containment vessel for molten aluminum

    DOEpatents

    Holcombe, Cressie E.; Scott, Donald G.

    1985-01-01

    The present invention is directed to a containment vessel which is particularly useful in melting aluminum. The vessel of the present invention is a multilayered vessel characterized by being electrically conductive, essentially nonwettable by and nonreactive with molten aluminum. The vessel is formed by coating a tantalum substrate of a suitable configuration with a mixture of yttria and particulate metal borides. The yttria in the coating inhibits the wetting of the coating while the boride particulate material provides the electrical conductivity through the vessel. The vessel of the present invention is particularly suitable for use in melting aluminum by ion bombardment.

  19. Domestic aluminum resources: dilemmas of development

    SciTech Connect

    Staats, E.B.

    1980-07-17

    Concerns about supply disruptions and price gouging that could endanger aluminum production in the United States have spurred research in this country on processes to manufacture aluminum from ores other than bauxite. The United States has no large bauxite deposits but it has plentiful resources of other aluminum ores if the technology can be developed to use them economically. Sources of aluminium include alunite, anorthosite, dawsonite, and clay/acid. Miniplants for clay/nitric acid and clay/hydrochloric acid, gas-induced crystallization have been constructed.

  20. Determination of aluminum diffusion parameters in silicon

    NASA Astrophysics Data System (ADS)

    Krause, O.; Ryssel, H.; Pichler, P.

    2002-05-01

    Aluminum as the fastest diffusing acceptor dopant in silicon is commonly used for the fabrication of power semiconductors with p-n junction depths ranging from some microns to more than a hundred microns. Although long used, its diffusion behavior was not sufficiently characterized to support computer-aided design of devices. In this work, the intrinsic diffusion of aluminum was investigated in the temperature range from 850 to 1290 °C. Combining nitridation and oxidation experiments, the fractional diffusivity via self-interstitials was determined. By diffusion in high-concentration boron- and phosphorus-doped silicon the behavior of aluminum under extrinsic conditions was investigated.

  1. SVC 2003 Technical Conference Summary

    SciTech Connect

    Martin, Peter M.

    2003-07-01

    The 46th Annual Technical Conference of the Society of Vacuum Coaters was held in San Francisco May 2-8. All the world events apparently did not affect the attendance or the spirit of the attendees. The Conference was a huge success and very well attended. Many feel that it was the best Techcon yet. This year's Conference really raised the bar for the 47th Annual Technical Conference in Dallas next year. Congratulations go out to the program committee, board of directors, education committee, scholarship committee and Management Plus for a job well done. Excellent accommodations were provided by the San Francisco Marriott.

  2. Control Center Technology Conference Proceedings

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Conference papers and presentations are compiled and cover evolving architectures and technologies applicable to flight control centers. Advances by NASA Centers and the aerospace industry are presented.

  3. 49 CFR 178.505 - Standards for aluminum drums.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Standards for aluminum drums. 178.505 Section 178... PACKAGINGS Non-bulk Performance-Oriented Packaging Standards § 178.505 Standards for aluminum drums. (a) The following are the identification codes for aluminum drums: (1) 1B1 for a non-removable head aluminum...

  4. 46 CFR 154.195 - Aluminum cargo tank: Steel enclosure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Aluminum cargo tank: Steel enclosure. 154.195 Section... Equipment Hull Structure § 154.195 Aluminum cargo tank: Steel enclosure. (a) An aluminum cargo tank and its... the aluminum cargo tank must meet the steel structural standards of the American Bureau of...

  5. 49 CFR 178.505 - Standards for aluminum drums.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Standards for aluminum drums. 178.505 Section 178...-bulk Performance-Oriented Packaging Standards § 178.505 Standards for aluminum drums. (a) The following are the identification codes for aluminum drums: (1) 1B1 for a non-removable head aluminum drum;...

  6. 49 CFR 178.505 - Standards for aluminum drums.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Standards for aluminum drums. 178.505 Section 178...-bulk Performance-Oriented Packaging Standards § 178.505 Standards for aluminum drums. (a) The following are the identification codes for aluminum drums: (1) 1B1 for a non-removable head aluminum drum;...

  7. 49 CFR 229.51 - Aluminum main reservoirs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Aluminum main reservoirs. 229.51 Section 229.51... Aluminum main reservoirs. (a) Aluminum main reservoirs used on locomotives shall be designed and fabricated as follows: (1) The heads and shell shall be made of Aluminum Association Alloy No. 5083-0,...

  8. 49 CFR 229.51 - Aluminum main reservoirs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Aluminum main reservoirs. 229.51 Section 229.51... Aluminum main reservoirs. (a) Aluminum main reservoirs used on locomotives shall be designed and fabricated as follows: (1) The heads and shell shall be made of Aluminum Association Alloy No. 5083-0,...

  9. 46 CFR 154.195 - Aluminum cargo tank: Steel enclosure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Aluminum cargo tank: Steel enclosure. 154.195 Section... Equipment Hull Structure § 154.195 Aluminum cargo tank: Steel enclosure. (a) An aluminum cargo tank and its... the aluminum cargo tank must meet the steel structural standards of the American Bureau of...

  10. 46 CFR 154.195 - Aluminum cargo tank: Steel enclosure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Aluminum cargo tank: Steel enclosure. 154.195 Section... Equipment Hull Structure § 154.195 Aluminum cargo tank: Steel enclosure. (a) An aluminum cargo tank and its... the aluminum cargo tank must meet the steel structural standards of the American Bureau of...

  11. 49 CFR 178.505 - Standards for aluminum drums.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Standards for aluminum drums. 178.505 Section 178...-bulk Performance-Oriented Packaging Standards § 178.505 Standards for aluminum drums. (a) The following are the identification codes for aluminum drums: (1) 1B1 for a non-removable head aluminum drum;...

  12. 49 CFR 178.505 - Standards for aluminum drums.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Standards for aluminum drums. 178.505 Section 178...-bulk Performance-Oriented Packaging Standards § 178.505 Standards for aluminum drums. (a) The following are the identification codes for aluminum drums: (1) 1B1 for a non-removable head aluminum drum;...

  13. 46 CFR 154.195 - Aluminum cargo tank: Steel enclosure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Aluminum cargo tank: Steel enclosure. 154.195 Section... Equipment Hull Structure § 154.195 Aluminum cargo tank: Steel enclosure. (a) An aluminum cargo tank and its... the aluminum cargo tank must meet the steel structural standards of the American Bureau of...

  14. 49 CFR 229.51 - Aluminum main reservoirs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Aluminum main reservoirs. 229.51 Section 229.51... Aluminum main reservoirs. (a) Aluminum main reservoirs used on locomotives shall be designed and fabricated as follows: (1) The heads and shell shall be made of Aluminum Association Alloy No. 5083-0,...

  15. 49 CFR 229.51 - Aluminum main reservoirs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Aluminum main reservoirs. 229.51 Section 229.51... Aluminum main reservoirs. (a) Aluminum main reservoirs used on locomotives shall be designed and fabricated as follows: (1) The heads and shell shall be made of Aluminum Association Alloy No. 5083-0,...

  16. 46 CFR 154.195 - Aluminum cargo tank: Steel enclosure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Aluminum cargo tank: Steel enclosure. 154.195 Section... Equipment Hull Structure § 154.195 Aluminum cargo tank: Steel enclosure. (a) An aluminum cargo tank and its... the aluminum cargo tank must meet the steel structural standards of the American Bureau of...

  17. 49 CFR 229.51 - Aluminum main reservoirs.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Aluminum main reservoirs. 229.51 Section 229.51... Aluminum main reservoirs. (a) Aluminum main reservoirs used on locomotives shall be designed and fabricated as follows: (1) The heads and shell shall be made of Aluminum Association Alloy No. 5083-0,...

  18. Explosive welding technique for joining aluminum and steel tubes

    NASA Technical Reports Server (NTRS)

    Wakefield, M. E.

    1975-01-01

    Silver sheet is wrapped around aluminum portion of joint. Mylar powder box is wrapped over silver sheet. Explosion welds silver to aluminum. Stainless-steel tube is placed over silver-aluminum interface. Mylar powder box, covered with Mylar tape, is wrapped around steel member. Explosion welds steel to silver-aluminum interface.

  19. Study of crevice-galvanic corrosion of aluminum

    NASA Technical Reports Server (NTRS)

    Draley, J. E.; Loess, R. E.; Mori, S.

    1967-01-01

    Corrosion effects of aluminum-copper and aluminum-nickel couples in oxygenated distilled water, and aluminum alloys in oxygenated copper sulfate solution were studied. One of each of the couples had a water tight seal, and showed no substantial corrosion, and of the unsealed couples, only the aluminum-copper developed corrosion.

  20. A simple aluminum gasket for use with both stainless steel and aluminum flanges

    SciTech Connect

    Langley, R.A.

    1991-01-01

    A technique has been developed for making aluminum wire seal gaskets of various sizes and shapes for use with both stainless steel and aluminum alloy flanges. The gasket material used is 0.9999 pure aluminum, drawn to a diameter of 3 mm. This material can be easily welded and formed into various shapes. A single gasket has been successfully used up to five times without baking. The largest gasket tested to date is 3.5 m long and was used in the shape of a parallelogram. Previous use of aluminum wire gaskets, including results for bakeout at temperatures from 20 to 660{degree}C, is reviewed. A search of the literature indicates that this is the first reported use of aluminum wire gaskets for aluminum alloy flanges. The technique is described in detail, and the results are summarized. 11 refs., 4 figs.