Sample records for aluminium additions

  1. Processing of aluminium alloys containing titanium addition by mechanical alloying

    Microsoft Academic Search

    K. R. Cardoso; C. A. D. Rodrigues; W. J. Botta F

    2004-01-01

    In this work, mechanical alloying was used to produce precursor powders of 2024 and 7050 aluminium alloys containing titanium addition. Milling was performed in a planetary mill using a ball to powder weight ratio of 20:1 and a milling time varying from 10 to 100h. Characterisation of the milled powders was performed by X-ray diffraction (XRD), differential scanning calorimetry (DSC)

  2. Characterisation of a BN magnetron sputtering process with an additional aluminium sputter electrode

    Microsoft Academic Search

    Th. Welzel; Th. Pfeifer; Th. Dunger; F. Richter

    2003-01-01

    The deposition of boron nitride (BN) films by r.f. magnetron sputtering of a hexagonal BN target with intended additional aluminium incorporation has been studied using various in situ plasma diagnostic techniques. The aluminium flux towards the substrates was supplied by an additional ring-shaped aluminium electrode mounted all around the circular magnetron. Langmuir double probe investigations reveal only little influence of

  3. Microstructure of a pressure die cast magnesium—4wt.% aluminium alloy modified with rare earth additions

    Microsoft Academic Search

    G. Pettersen; H. Westengen; R. Høier; O. Lohne

    1996-01-01

    Addition of cerium-rich mixtures of rare earth (RE) elements to aluminium-containing magnesium pressure die cast alloys is known to improve the creep properties at elevated temperatures. In the present investigation, a detailed description of the microstructure of a magnesium-4 wt.% aluminium alloy containing 1.4 wt.% of a cerium-rich mixture of RE elements is presented. Particle types occurring and their distribution

  4. Aluminium as anode in primary alkaline batteries. Influence of additives on the corrosion and anodic behaviour of 2S aluminium in alkaline citrate solution

    Microsoft Academic Search

    K. B. Sarangapani; V. Balaramachandran; V. Kapali; S. Venkatakrishna Iyer; M. G. Potdar; K. S. Rajagopalan

    1984-01-01

    The inhibitive effects of various additives on the corrosion of 2S aluminium in 4N NaOH containing calcium oxide and sodium citrate (base electrolyte) have been examined by studying the self corrosion, anodic polarization and anode efficiency of 2S aluminium in solutions containing different additives. It has been found that among the different additives investigated, those forming anions in solution act

  5. Effect of titanium additions on the microstructure of DC-cast aluminium alloys

    Microsoft Academic Search

    Majed Jaradeh; Torbjörn Carlberg

    2005-01-01

    The effect of the Ti content on the solidification structures of aluminum alloys of AA3003 type was investigated. Some improved corrosion properties can be obtained from increasing the Ti contents in aluminium alloys to a level above the normal practice for grain refinement. However, increasing the Ti content above the peritectic point, 0.15%, can influence the grain refinement and cause

  6. Imidazolium ionic liquids as additives of the synthetic ester propylene glycol dioleate in aluminium–steel lubrication

    Microsoft Academic Search

    Ana-Eva Jiménez; María-Dolores Bermúdez

    2008-01-01

    Four room-temperature ionic liquids (ILs), 1-CnH2n+1-3-CH3-imidazolium X? [X=PF6; n=6 (L-P106). X=BF4; n=2 (L102), 6 (L106). X=CF3SO3; n=2 (L-T102)], have been studied as 1wt.% additives of the synthetic ester propylene glycol dioleate (PGDO) in pin-on-disk tests for AISI 52100 steel–ASTM 2011 aluminium contacts at 25 and 100°C. At room temperature, friction values for PGDO+1wt.% IL are similar or higher than that

  7. Room temperature ionic liquids as lubricant additives in steel–aluminium contacts: Influence of sliding velocity, normal load and temperature

    Microsoft Academic Search

    A. E. Jiménez; M. D. Bermúdez; F. J. Carrión; G. Martínez-Nicolás

    2006-01-01

    1-n-Alkyl-3-methylimidazolium X? [X=PF6; n=6 (L-P106). X=BF4; n=2 (L102), 6 (L106), 8 (L108). X=CF3SO3; n=2 (L-T102). X=(4-CH3C6H4SO3); n=2 (L-To102)] and 1-butyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide (L-PY104) have been studied as 1wt.% base oil additives in variable conditions pin-on-disk tests for AISI 52100 steel-ASTM 2011 aluminium contacts. Friction coefficients and wear rates increase under increasing normal loads. Effective lubrication is obtained for a 0.15–0.20ms?1 sliding

  8. Aluminium content of some processed foods, raw materials and food additives in China by inductively coupled plasma–mass spectrometry

    Microsoft Academic Search

    Gui-Fang Deng; Ke Li; Jing Ma; Fen Liu; Jing-Jing Dai; Hua-Bin Li

    2011-01-01

    The level of aluminium in 178 processed food samples from Shenzhen city in China was evaluated using inductively coupled plasma–mass spectrometry. Some processed foods contained a concentration of up to 1226?mg\\/kg, which is about 12 times the Chinese food standard. To establish the main source in these foods, Al levels in the raw materials were determined. However, aluminium concentrations in

  9. Friction and wear of aluminium–steel contacts lubricated with ordered fluids-neutral and ionic liquid crystals as oil additives

    Microsoft Academic Search

    P. Iglesias; M. D. Bermúdez; F. J. Carrión; G. Mart??nez-Nicolás

    2004-01-01

    Friction and wear of ASTM B211 aluminium–AISI 52100 steel contacts have been determined using pin-on-disk tests under variable conditions of normal applied load, sliding speed and temperature, in the presence of a lubricating base oil modified with a 1wt.% proportion of three different liquid crystalline additives.The tribological behavior of the ionic liquid crystal n-dodecylammonium chloride (LC3) has been compared with

  10. Aluminium toxicity during regular haemodialysis

    Microsoft Academic Search

    H L Elliott; F Dryburgh; G S Fell; S Sabet; A I Macdougall

    1978-01-01

    In the west of Scotland the incidence of dialysis encephalopathy has been confined to three geographical areas where the concentration of aluminium in the water supply is greatly increased owing to the addition of aluminium sulphate. Eight patients with encephalopathy who dialysed at home in these areas had greatly increased serum aluminium concentrations, and a significant correlation was found between

  11. 1- N-alkyl -3-methylimidazolium ionic liquids as neat lubricants and lubricant additives in steel–aluminium contacts

    Microsoft Academic Search

    A. E. Jiménez; M. D. Bermúdez; P. Iglesias; F. J. Carrión; G. Martínez-Nicolás

    2006-01-01

    The influence of the alkyl chain length and of the anion on the lubricating ability has been studied for the room-temperature ionic liquids (IL) 1-n-alkyl-3-methylimidazolium X? [X=PF6; n=6 (L-P106). X=BF4; n=2 (L102), 6 (L106), 8 (L108). X=CF3SO3; n=2 (L-T102). X=(4-CH3C6H4SO3); n=2 (L-To102)]. Neat IL have been used for AISI 52100 steel-ASTM 2011 aluminium contacts in pin-on-disk tests under variable sliding

  12. Influence of alloying additives on the performance of commercial grade aluminium as galvanic anode in alkaline zincate solution for use in primary alkaline batteries

    Microsoft Academic Search

    M. Paramasivam; M. Jayachandran; S. Venkatakrishna Iyer

    2003-01-01

    The self-corrosion of different grades of commercial aluminium such as 2S, 3S, 26S and 57S in 4 M NaOH containing 0.6 M ZnO has been determined by weight loss measurements. It is found that 26S and 57S aluminium exhibit negligible corrosion rates in the range 0.05–0.06 mg cm-2 min-1, which can be attributed to the formation of a zincate coating

  13. Evidence of aluminium accumulation in aluminium welders.

    PubMed Central

    Elinder, C G; Ahrengart, L; Lidums, V; Pettersson, E; Sjögren, B

    1991-01-01

    Using atomic absorption spectrometry the aluminium concentrations in blood and urine and in two iliac bone biopsies obtained from welders with long term exposure to fumes containing aluminium were measured. The urinary excretion of two workers who had welded for 20 and 21 years varied between 107 and 351 micrograms Al/l, more than 10 times the concentration found in persons without occupational exposure. Urinary aluminium excretion remained high many years after stopping exposure. Blood and bone aluminium concentrations (4-53 micrograms Al/l and 18-29 micrograms Al/g respectively) were also raised but not to the same extent as urine excretion. It is concluded that long term exposure to aluminium by inhalation gives rise to accumulation of aluminium in the body and skeleton of health persons, and that the elimination of retained aluminium is very slow, in the order of several years. PMID:1954151

  14. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  15. Environmental effects of aluminium.

    PubMed

    Rosseland, B O; Eldhuset, T D; Staurnes, M

    1990-03-01

    Aluminium (Al), when present in high concentrations, has for long been recognised as a toxic agent to aquatic freshwater organisms,i.e. downstream industrial point sources of Al-rich process water. Today the environmental effects of aluminium are mainly a result of acidic precipitation; acidification of catchments leads to increased Al- concentrations in soil solution and freshwaters. Large parts of both the aquatic and terrestrial ecosystems are affected.In the aquatic environment, aluminium acts as a toxic agent on gill-breathing animals such as fish and invertebrates, by causing loss of plasma- and haemolymph ions leading to osmoregulatory failure. In fish, the inorganic (labile) monomeric species of aluminium reduce the activities of gill enzymes important in the active uptake of ions. Aluminium seems also to accumulate in freshwater invertebrates. Dietary organically complexed aluminium, maybe in synergistic effects with other contaminants, may easily be absorbed and interfere with important metabolic processes in mammals and birds.The mycorrhiza and fine root systems of terrestrial plants are adversely affected by high levels of inorganic monomeric aluminium. As in the animals, aluminium seems to have its primary effect on enzyme systems important for the uptake of nutrients. Aluminium can accumulate in plants. Aluminium contaminated invertebrates and plants might thus be a link for aluminium to enter into terrestrial food chains. PMID:24202562

  16. Static and dynamic crushing of square aluminium extrusions with aluminium foam filler

    Microsoft Academic Search

    A. G. Hanssen; M. Langseth; O. S. Hopperstad

    2000-01-01

    An experimental programme consisting of 144 tests was carried out to study the behaviour of triggered, square 80×80mm2 AA6060 aluminium extrusions filled with aluminium foam under both quasi-static and dynamic axial loading conditions. The main parameters in addition to the loading condition were the foam density, the extrusion wall strength and the extrusion wall thickness. Previously proposed design formulas applied

  17. Static and dynamic crushing of circular aluminium extrusions with aluminium foam filler

    Microsoft Academic Search

    A. G. Hanssen; M. Langseth; O. S. Hopperstad

    2000-01-01

    An experimental programme consisting of 96 tests was carried out to study the axial deformation behaviour of triggered, circular AA6060 aluminium extrusions filled with aluminium foam under both quasi-static and dynamic loading conditions. The outer diameter and length of the columns were kept constant at 80mm and 230mm, respectively. The main parameters in addition to the loading condition were the

  18. Aluminium oxide microchannel plates

    NASA Astrophysics Data System (ADS)

    Delendik, K.; Emeliantchik, I.; Litomin, A.; Rumyantsev, V.; Voitik, O.

    2003-09-01

    Microchannel electron multipliers of a new type are proposed - anodic alumina microchannel plates (MCP). They implement the conventional concept of lead glass microchannel plate with a new material - anodic aluminium oxide. Anodic alumina is a very suitable material for microchannel plates due to presense of natural microchannels. Diameters of these channels lie in the range of 0.02 - 0.5 ?m, channels of greater diameter can be easily produced by means of additional processing based on the presence of intrinsic microchannel structure. We have produced MCPs with channel diameters 0.2 - 8 ?m and thickness 40 - 150 ?m. We have also developed two methods of deposition of conductive and emissive films inside MCP channels: plasma sputtering and liquid-phase deposition from metallo-organic precursors. MCP samples with NiO?MgO and Cu?CuO?BeO?MgO coatings have demonstrated promising results. Alumina MCP potentially have serious advantages over traditional lead glass MCP: they are much cheaper, large area plates (hundreds of cm2) can be easily produced, spatial resolution can be much better (due to smaller channel diameter).

  19. Molecular breeding of cereals for aluminium resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aluminium (Al3+) toxicity is the primary factor limiting crop production on acidic soils worldwide. In addition to an application of lime for soil amelioration, Al3+ resistant plant varieties have been deployed to raise productivity on such hostile soils. This has been possible due to the exploita...

  20. Aluminium Electroplating on Steel from a Fused Bromide Electrolyte

    SciTech Connect

    Prabhat Tripathy; Laura Wurth; Eric Dufek; Toni Y. Gutknecht; Natalie Gese; Paula Hahn; Steven Frank; Guy Fredrickson; J Stephen Herring

    2014-08-01

    A quaternary bromide bath (LiBr-KBr-CsBr-AlBr3) was used to electro-coat aluminium on steel substrates. The electrolyte was prepared by the addition of AlBr3 into the eutectic LiBr-KBr-CsBr melt. A smooth, thick, adherent and shiny aluminium 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 aluminium coverage. Both salt immersion and open circuit potential measurement suggest that the coatings did display good corrosion-resistance behavior. Annealing of the coated surfaces, prior to corrosion tests, suggested the robustness of the metallic aluminium coating in preventing the corrosion of the steel surfaces. Studies also indicated that the quaternary bromide plating bath can potentially provide a better aluminium coating on both ferrous and non-ferrous metals, including complex surfaces/geometries.

  1. Greening the aluminium supply chain

    Microsoft Academic Search

    I. Ferretti; S. Zanoni; L. Zavanella; A. Diana

    2007-01-01

    This paper originated from an industrial case study in the field of the aluminium supply chain. In particular, the most original aspects of the study are linked to the use of an alternative supply method for raw material (aluminium) in manufacturing. This method consists in the possibility of the company receiving the aluminium alloy from its supplier (refiner and remelter

  2. Dietary exposure to aluminium of the Hong Kong population.

    PubMed

    Wong, Waiky W K; Chung, Stephen W C; Kwong, K P; Yin Ho, Yuk; Xiao, Ying

    2010-04-01

    A total of 256 individual food samples were collected in Hong Kong for aluminium testing. Most of food samples were analysed in ready-to-eat form. High aluminium levels were found in steamed bread/bun/cake (mean: 100-320 mg kg(-1)), some bakery products such as muffin, pancake/waffle, coconut tart and cake (mean: 250, 160, 120 and 91 mg kg(-1), respectively), and jellyfish (ready-to-eat form) (mean: 1200 mg kg(-1)). The results demonstrated that aluminium-containing food additives have been widely used in these food products. The average dietary exposure to aluminium for a 60 kg adult was estimated to be 0.60 mg kg(-1) bw week(-1), which amounted to 60% of the new PTWI established by JECFA. The main dietary source was "steamed bread/bun/cake", which contributed to 60% of the total exposure, followed by "bakery products" and "jellyfish", which contributed to 23 and 10% of the total exposure, respectively. However, the estimation did not include the intake of aluminium from natural food sources, food contact materials or other sources (e.g. drinking water). Although the results indicated that aluminium it is unlikely to cause adverse health effect for the general population, the risk to some populations who regularly consume foods with aluminium-containing food additives cannot be ruled out. PMID:20234962

  3. Aluminium phosphide poisoning.

    PubMed

    Bogle, R G; Theron, P; Brooks, P; Dargan, P I; Redhead, J

    2006-01-01

    We describe a lethal poisoning in a healthy woman caused by deliberate ingestion of aluminium phosphide (AlP), a pesticide used to kill rodents and insects. Toxicity of AlP and review of cases reported to the National Poisons Information Service (London) 1997-2003 are discussed. PMID:16373788

  4. Tribological properties of aluminium-based materials

    NASA Astrophysics Data System (ADS)

    Iglesias Victoria, Patricia

    In order to improve the tribological performance of the aluminium-steel contact, two research lines have been followed: (1) Use of the ordered fluids liquid crystals and ionic liquids as lubricant additives. (2) Tribological behaviour of new powder metallurgy aluminium materials processed by mechanical milling. A parafinic-naftenic base oil modified by a 1wt% of four additives has been used: Three liquid crystals with increasing polarity: 4,4' -dibutylazobenzene (LC1) < colesteryl linoleate (LC2) < n-dodecyl ammonium chloride (LC3), and the ionic liquid 1-ethyl, 3-methyl-imidazolonium tetrafluoroborate. This is the first time that a ionic liquid is studied as lubricant additive. Viscosity measurements at 25 and 100°C, maximum number of molecules by unit aluminium surface and comparative costs of the additives showed the advantage of the ionic additives over the neutral ones. Pin-on-disk tests were performed according to ASTM G99. Influence of load, speed and temperature on friction and wear was studied for each additive. While the ionic liquid gives low friction (<0.1) and wear (?10-5 mm3m-1), the performance of the liquid crystalline additives depends on the conditions. LC3 shows a higher lubricating ability than the neutral LC1 and LC2 under high load, speed or temperature. Only the ionic liquid shows tribochemical interaction (by SEM and EDS) with the steel and aluminium surfaces, with an increment in the fluorine content inside the wear track. The second line was to study the influence of the process conditions on the dry and lubricated wear of new powder-metallurgy aluminium materials. MA Al-NH3 milled under NH3 atmosphere was compared with (MA Al-Air) processed in air and with Al-1 which has not been mechanically alloyed. Conditions for mild to severe wear transition have been established. Al-1 is always under a severe wear regime. MA Al-NH3 shows transition to severe wear at 150°C, showing a 60% reduction in wear rate with respect to MA Al-Air and a two order of magnitude reduction with respect to Al-1. The wear resistance of MA Al-NH3 is attributed to its high hardness, lower porosity, and fine microstructure with submicroscopic reinforcing phases such as aluminium carbide and nitride (by X-ray diffraction and TEM observations).

  5. Risk of increased aluminium burden in the Indian population: contribution from aluminium cookware

    Microsoft Academic Search

    M Neelam; M. S Bamji; M Kaladhar

    2000-01-01

    Aluminium (Al) is a well-established potential neurotoxin in addition to its role in the aetiopathogenesis of certain disorders related to bone and blood. Food and water are the major sources of Al ingestion in normal population groups. Al content of certain cooked foods was therefore analysed to assess its daily burden in the Indian population. Significant levels of Al were

  6. Thixoforming 7075 aluminium alloys

    Microsoft Academic Search

    S. Chayong; H. V. Atkinson; P. Kapranos

    2005-01-01

    Commercially extruded 7075 alloy (extrusion ratio of 16:1) has been used as a feedstock for thixoforming in order to investigate thixoformability of a high performance aluminium alloy. The microstructure in the semi-solid state consists of fine spheroidal solid grains surrounded by liquid. The results of thixoforming with one step, two-step and three-step induction heating regimes are presented. Typical defects in

  7. Polymeric corrosion inhibitors for aluminium pigment

    Microsoft Academic Search

    Bodo Müller

    1999-01-01

    In aqueous alkaline media (e.g. water-borne metallic paints) aluminium pigments react by the evolution of hydrogen. This corrosion reaction can be inhibited by addition of different water-soluble polymers with carboxyl groups like polyacrylic acids, styrene–maleic acid or styrene–acrylate copolymers. As a rough empirical rule can be stated that the corrosion-inhibiting effect of polymers with carboxyl groups increases with decreasing molecular

  8. Static crushing of square aluminium extrusions with aluminium foam filler

    Microsoft Academic Search

    A. G. Hanssen; M. Langseth; O. S. Hopperstad

    1999-01-01

    An experimental investigation was carried out to study the behaviour of square aluminium extrusions filled with aluminium foam under quasi-static loading conditions. Based on the experimental work, simple relations between dimensionless numbers governing the influence of the foam on the characteristics of the crush problem were identified. Furthermore, a simplified set of equations applicable for design of foam-filled components was

  9. The influence of aluminium sources on the acidic behaviour as well as on the catalytic activity of mesoporous H-AlMCM-41 molecular sieves

    Microsoft Academic Search

    A Sakthivel; S. E Dapurkar; N. M Gupta; S. K Kulshreshtha; P Selvam

    2003-01-01

    A series of mesoporous molecular sieves (AlMCM-41) were synthesized with varying silicon-to-aluminium ratios and using three different aluminium sources, viz., sodium aluminate, aluminium isopropoxide and aluminium sulphate. The samples were characterized systematically using XRD, TG-DTA, BET surface area, and ICP-AES. In addition, the extent of framework substitution as well as the nature of acid sites was deduced employing 27Al MAS-NMR,

  10. Aluminium Involvement in Neurotoxicity

    PubMed Central

    Fulgenzi, Alessandro; Vietti, Daniele; Ferrero, Maria Elena

    2014-01-01

    The aetiology of neurodegenerative diseases (ND) seems to involve susceptibility genes and environmental factors. Toxic metals are considered major environmental pollutants. Following our study of a case of multiple sclerosis (MS) improvement due to removal of aluminium (Al) and other toxic metals, we have examined the possible relationship between Al intoxication and ND. We used the slow intravenous treatment with the chelating agent EDTA (calcium disodium ethylene diamine tetraacetic acid) (chelation test) to remove Al and detected it in the urine collected from the patients for 12 hours. Patients affected by MS represented 85.6% of total ND. Al was present in 44.8% of cases comprehensive of ND and healthy patients. Al levels were significantly higher in ND patients than in healthy subjects. We here show that treatment of patients affected by Al burden with ten EDTA chelation therapies (EDTA intravenous administration once a week) was able to significantly reduce Al intoxication. PMID:25243176

  11. Dependence in Classification of Aluminium Waste

    NASA Astrophysics Data System (ADS)

    Resti, Y.

    2015-06-01

    Based on the dependence between edge and colour intensity of aluminium waste image, the aim of this paper is to classify the aluminium waste into three types; pure aluminium, not pure aluminium type-1 (mixed iron/lead) and not pure aluminium type 2 (unrecycle). Principal Component Analysis (PCA) was employed to reduction the dimension of image data, while Bayes’ theorem with the Gaussian copula was applied to classification. The copula was employed to handle dependence between edge and colour intensity of aluminium waste image. The results showed that the classifier has been correctly classifiable by 88.33%.

  12. Optimization of phosphate removal in anodizing aluminium wastewater

    Microsoft Academic Search

    J. M. Chimenos; A. I. Fernández; A. Hernández; L. Haurie; F. Espiell; C. Ayora

    2006-01-01

    The wastewater produced after brightening and anodizing aluminium has high concentrations of phosphates and sulphates. The addition of MgO in a first physico-chemical wastewater treatment step makes the selective recovery of phosphates in the form of magnesium phosphates feasible, which may be reused as fertilizer. The proposed wastewater treatment process allows manufacturers to reduce more than 70% of the volume

  13. Laser pressure welding of aluminium and galvannealed steel

    Microsoft Academic Search

    Koji Nishimoto; Yoshihiro Okumoto; Tomoki Harano; Ken Atagi; Hiroo Fujii; Seiji Katayama

    2009-01-01

    Dissimilar metal joints of galvannealed steel and commercially available pure aluminium (A1050) sheets were produced by changing the laser power and the roller pressure by the laser pressure welding method. In this method, the YAG laser beam was irradiated into a flare groove made by these dissimilar metal sheets. In addition, the laser beam was scanned at various frequencies and

  14. Freeform fabrication of functional aluminium prototypes using powder metallurgy

    Microsoft Academic Search

    T. B. Sercombe; G. B. Schaffer; P. Calvert

    1999-01-01

    Freeform fabrication methods allow the direct formation of parts built layer by layer, under the control of a CAD drawing. Most of these methods form parts in thermoplastic or thermoset polymers, but there would be many applications for freeform fabrication of fully functional metal or ceramic parts. We describe here the freeforming of sinterable aluminium alloys. In addition, the building

  15. Crushing of axially compressed steel tubes filled with aluminium foam

    Microsoft Academic Search

    M. Seitzberger; F. G. Rammerstorfer; H. P. Degischer; R. Gradinger

    1997-01-01

    Summary This study, with the emphasis on experiments, investigates the applicability of aluminium foam as filler material in tubes made of mild steel having square or circular cross sections, which are crushed axially at low loading velocities. In addition to the experiments finite element studies are performed to simulate the crushing behaviour of the tested square tubes, were a crushable

  16. Pulmonary Fibrosis in an Aluminium Worker

    PubMed Central

    Mitchell, John

    1959-01-01

    Aluminium dust has never been shown to be harmful to man in Great Britain. This paper reports a fatal case of progressive pulmonary fibrosis in a young man occupationally exposed to a heavy concentration of fine aluminium dust. Clinically, radiologically, and pathologically this case was indistinguishable from cases of aluminium fibrosis of the lung described by Shaver in Canada. Images PMID:13651554

  17. Bumblebee Pupae Contain High Levels of Aluminium

    PubMed Central

    Exley, Christopher; Rotheray, Ellen; Goulson, David

    2015-01-01

    The causes of declines in bees and other pollinators remains an on-going debate. While recent attention has focussed upon pesticides, other environmental pollutants have largely been ignored. Aluminium is the most significant environmental contaminant of recent times and we speculated that it could be a factor in pollinator decline. Herein we have measured the content of aluminium in bumblebee pupae taken from naturally foraging colonies in the UK. Individual pupae were acid-digested in a microwave oven and their aluminium content determined using transversely heated graphite furnace atomic absorption spectrometry. Pupae were heavily contaminated with aluminium giving values between 13.4 and 193.4 ?g/g dry wt. and a mean (SD) value of 51.0 (33.0) ?g/g dry wt. for the 72 pupae tested. Mean aluminium content was shown to be a significant negative predictor of average pupal weight in colonies. While no other statistically significant relationships were found relating aluminium to bee or colony health, the actual content of aluminium in pupae are extremely high and demonstrate significant exposure to aluminium. Bees rely heavily on cognitive function and aluminium is a known neurotoxin with links, for example, to Alzheimer’s disease in humans. The significant contamination of bumblebee pupae by aluminium raises the intriguing spectre of cognitive dysfunction playing a role in their population decline. PMID:26042788

  18. Bumblebee pupae contain high levels of aluminium.

    PubMed

    Exley, Christopher; Rotheray, Ellen; Goulson, David

    2015-01-01

    The causes of declines in bees and other pollinators remains an on-going debate. While recent attention has focussed upon pesticides, other environmental pollutants have largely been ignored. Aluminium is the most significant environmental contaminant of recent times and we speculated that it could be a factor in pollinator decline. Herein we have measured the content of aluminium in bumblebee pupae taken from naturally foraging colonies in the UK. Individual pupae were acid-digested in a microwave oven and their aluminium content determined using transversely heated graphite furnace atomic absorption spectrometry. Pupae were heavily contaminated with aluminium giving values between 13.4 and 193.4 ?g/g dry wt. and a mean (SD) value of 51.0 (33.0) ?g/g dry wt. for the 72 pupae tested. Mean aluminium content was shown to be a significant negative predictor of average pupal weight in colonies. While no other statistically significant relationships were found relating aluminium to bee or colony health, the actual content of aluminium in pupae are extremely high and demonstrate significant exposure to aluminium. Bees rely heavily on cognitive function and aluminium is a known neurotoxin with links, for example, to Alzheimer's disease in humans. The significant contamination of bumblebee pupae by aluminium raises the intriguing spectre of cognitive dysfunction playing a role in their population decline. PMID:26042788

  19. The molar enthalpies of solution and vapour pressures of saturated aqueous solutions of aluminium chloride, aluminium nitrate and aluminium sulphate

    Microsoft Academic Search

    Alexander Apelblat; Eli Korin

    2002-01-01

    Vapour pressures of water over saturated solutions of aluminium chloride, aluminium nitrate and aluminium sulphate were determined as a function of temperature. The vapour pressures served to evaluate the water activities, osmotic coefficients and molar enthalpies of vaporization. Molar enthalpies of solution of aluminium chloride hexahydrate, ?solHm(AlCl3·6H2O, T=295.02K, m=0.02084mol·kg?1)=?(54.6±2.1)kJ·mol?1, aluminium nitrate nonahydrate, ?solHm(Al(NO3)3·9H2O; T=296.62K, m=0.01342mol·kg?1)=(30.7±1.0)kJ·mol?1 and aluminium sulphate octadecahydrate, ?solHm(Al2(SO4)3·18H2O,

  20. Aluminium in Allergies and Allergen immunotherapy.

    PubMed

    Jensen-Jarolim, Erika

    2015-01-01

    Aluminium is a hot topic in the current debate. Exposure occurs due to environmental, dietary and intentional exposure to aluminium, such as in vaccines where it was introduced in 1926. In spite of the fact that it is a typical Th2 adjuvant, aluminium redirects the immune response in systemic allergen immunotherapy (SIT) upon prolonged immunization. SIT in the US, and SLIT in general, are at present non-adjuvanted therapies, but in Europe aluminium is used as adjuvant in most SIT preparations. It enhances the safety of SIT by local deposition of the allergen. Undesired properties of aluminium adjuvants comprise acute and chronic inflammation at the injection site, its Th2 immune stimulatory capacity, its accumulation besides biodistribution in the body. The adjuvant and safety profile of aluminium adjuvants in allergy vaccines are discussed, as well as the need for putting modern delivery systems and adjuvants on the fast track. PMID:25780491

  1. Serum aluminium levels in glue-sniffer adolescent and in glue containers.

    PubMed

    Akay, Cemal; Kalman, Süleyman; Dündaröz, Ru?en; Sayal, Ahmet; Aydin, Ahmet; Ozkan, Yalçin; Gül, Hüsamettin

    2008-05-01

    Glue sniffing is a serious medical problem among teenagers. Various chemical substances such as toluene and benzene containing glues have been reported to be toxic. It has been demonstrated that some toxic metals such as lead are elevated in the blood of solvent-addicted patients. Whereas aluminium is an element that has toxic effects on neurological, hematopoetic system and bone metabolism. We want to determine the serum levels of aluminium in glue-sniffer adolescents in comparison with healthy subjects. In addition, we compared aluminium levels of different commercial glue preparations (i.e. metal and plastic containers), to determine which type of container is better for less aluminium toxicity. We measured serum levels of aluminium in 37 glue-sniffer and 37 healthy subjects using atomic absorption spectrophotometry. The average duration of glue-sniffer was 3.8 +/- 0.8 years. We also measured aluminium levels of 10 commercial glue preparations that seven of them with metal and three with plastic containers. We found that serum levels of aluminium were 63.29 +/- 13.20 ng/ml and 36.7 +/- 8.60 ng/ml in glue-sniffer and in control subjects, respectively (P < 0.001). The average aluminium level in the glues was 8.6 +/- 3.24 ng/g in the preparations with metal containers, whereas 3.03 +/- 0.76 ng/g with plastic containers (P < 0.001). Therefore, to decrease the incidence of aluminium toxicity in glue-sniffers, it may be a good step to market of glue preparations in plastic instead of metal containers. PMID:18331391

  2. Investigation of the aluminium-aluminium oxide reversible transformation as observed by hot stage electron microscopy

    Microsoft Academic Search

    C. A. Grove; G. Judd; G. S. Ansell

    1972-01-01

    Thin foils of high purity aluminium and an Al-Al2O3 SAP type of alloy were oxidised in a specially designed hot stage specimen chamber in an electron microscope. Below 450\\u000a C, amorphous aluminium oxide formed on the foil surface and was first detectable at foil edges, holes, and pits. Islands of\\u000a aluminium then nucleated in this amorphous oxide. The aluminium islands

  3. Melt spun aluminium alloys for moulding optics

    NASA Astrophysics Data System (ADS)

    Gubbels, G.; Tegelaers, L.; Senden, R.

    2013-09-01

    Melt spinning is a rapid quenching process that makes it possible to create materials with a very fine microstructure. Due to this very fine microstructure the melt spinning process is an enabler for diamond turning optics and moulds without the need of post-polishing. Using diamond turning of melt spun aluminium one can achieve <=2 nm Rq surface roughness. Application areas are imaging and projection optics, mirrors, moulds for contact lenses and spectacles. One of the alloys that RSP produces is RSA-905. This alloy has a solid track record as a better and cheaper concept in the application of moulds for optical components such as contact lenses. The RSA-905 is a dispersion hardened amorphous-like alloy that keeps its properties when exposed to elevated temperatures (up to 380°C). This gives the material unique features for optics moulding applications. RSA-905 moulds are cheaper and better than traditional mould concepts such as copper or brass with or without NiP plating. In addition logistics can be simplified significantly: from typical weeks-months into days-week. Lifetime is typically in the range of 100.000 - 200.000 shots. For high volume production typically ranging from several 100.000 - several 1.000.000 shots, NiP plated steel moulds are typically used. By using an appropriate optical coating concept RSA-905 can be upgraded to a competitive alternative to steel in terms of price, performance and logistics. This paper presents some recent developments for improved mould performance of such concept. Hardness, wear resistance and adhesion are topics of interest and they can be applied by special coatings such as diamond-like carbon (DLC) and chromium nitride (CrN). These coatings make the aluminium alloy suitable for moulding mass production of small as well as larger optics, such as spectacle lenses.

  4. Faulted dislocation loops in quenched aluminium

    Microsoft Academic Search

    J. W. Edington; R. E. Smallman

    1965-01-01

    Dislocation loops containing stacking faults have been observed in quenched aluminium using the electron microscope. It is found that lowering the quenching rate relaxes the stringent purity conditions governing the retention of faulted loops, such that a high proportion of the loops in oil-quenched aluminium (99·97 % purity) contain faults. The results are discussed in terms of the influence of

  5. Feasibility of warm drawing of aluminium products

    Microsoft Academic Search

    P. J Bolt; N. A. P. M Lamboo; P. J. C. M Rozier

    2001-01-01

    A study is carried out on the feasibility of using warm forming at temperatures from 100 to 250°C in order to improve the makeability of aluminium sheet components. Drawing tests are performed on 1050, 5754 and 6016 series aluminium sheets. Both box shaped and conical rectangular products are made with a tool with heated die and blankholder. The effect of

  6. Biological indicators of exposure to total and respirable aluminium dust fractions in a primary aluminium smelter.

    PubMed Central

    Röllin, H B; Theodorou, P; Cantrell, A C

    1996-01-01

    OBJECTIVES: The study attempts to define biological indicators of aluminium uptake and excretion in workers exposed to airborne aluminium compounds in a primary aluminium smelter. Also, this study defines the total and respirable aluminium dust fractions in two different potrooms, and correlates their concentrations with biological indicators in this group of workers. METHODS: Air was sampled at defined work sites. Non-destructive and conventional techniques were used to find total and respirable aluminium content of the dust. Blood and urine was collected from 84 volunteers employed at various work stations throughout the smelter and from two different cohorts of controls matched for sex, age, and socioeconomic status. Aluminium in serum samples and urine specimens was measured by flameless atomic absorption with a PE 4100 ZL spectrometer. RESULTS: The correlation of aluminium concentrations in serum and urine samples with the degree of exposure was assessed for three arbitrary exposure categories; low (0.036 mg Al/m3), medium (0.35 mg Al/m3) and high (1.47 mg Al/m3) as found in different areas of the smelter. At medium and high exposure, the ratio of respirable to total aluminium in the dust samples varied significantly. At high exposure, serum aluminium, although significantly raised, was still within the normal range of an unexposed population. The workers with low exposure excreted aluminium in urine at levels significantly higher than the controls, but still within the normal range of the population. However, potroom workers with medium and high exposure had significantly higher urinary aluminium than the normal range. CONCLUSIONS: It is concluded that only urinary aluminium constitutes a practical index of occupational exposure at or above 0.35 mg Al/m3, and that the respirable fraction of the dust may play a major role in the biological response to exposure to aluminium in a smelter environment. PMID:8758038

  7. Aluminium in Biological Environments: A Computational Approach

    PubMed Central

    Mujika, Jon I; Rezabal, Elixabete; Mercero, Jose M; Ruipérez, Fernando; Costa, Dominique; Ugalde, Jesus M; Lopez, Xabier

    2014-01-01

    The increased availability of aluminium in biological environments, due to human intervention in the last century, raises concerns on the effects that this so far “excluded from biology” metal might have on living organisms. Consequently, the bioinorganic chemistry of aluminium has emerged as a very active field of research. This review will focus on our contributions to this field, based on computational studies that can yield an understanding of the aluminum biochemistry at a molecular level. Aluminium can interact and be stabilized in biological environments by complexing with both low molecular mass chelants and high molecular mass peptides. The speciation of the metal is, nonetheless, dictated by the hydrolytic species dominant in each case and which vary according to the pH condition of the medium. In blood, citrate and serum transferrin are identified as the main low molecular mass and high molecular mass molecules interacting with aluminium. The complexation of aluminium to citrate and the subsequent changes exerted on the deprotonation pathways of its tritable groups will be discussed along with the mechanisms for the intake and release of aluminium in serum transferrin at two pH conditions, physiological neutral and endosomatic acidic. Aluminium can substitute other metals, in particular magnesium, in protein buried sites and trigger conformational disorder and alteration of the protonation states of the protein's sidechains. A detailed account of the interaction of aluminium with proteic sidechains will be given. Finally, it will be described how alumnium can exert oxidative stress by stabilizing superoxide radicals either as mononuclear aluminium or clustered in boehmite. The possibility of promotion of Fenton reaction, and production of hydroxyl radicals will also be discussed. PMID:24757505

  8. Pulse electrodeposition of adherent nickel coatings onto anodized aluminium surfaces

    NASA Astrophysics Data System (ADS)

    Frantz, Cédric; Vichery, Charlotte; Zechner, Johannes; Frey, Damian; Bürki, Gerhard; Cebeci, Halil; Michler, Johann; Philippe, Laetitia

    2015-03-01

    Aluminium is one of the mostly used elements in the industry because of its abundance and low weight. However, the deposition of a metallic coating requires performing the so-called zincate pre-treatment in order to allow the formation of inter-metallic bonds and thereby achieving sufficient adherence. In this work, porous anodic aluminium oxide (AAO) is used as an anchoring intermediate layer for nickel coatings. AAO is grown anodically in sulfuric acid and nickel coatings are deposited by potentiostatic reverse pulse electrodeposition onto as-anodized aluminium surfaces. The electrodeposition of nickel is initiated onto the electrochemically thinned barrier layer of AAO and pursued until the complete covering of the oxide. The electrochemical behavior of Watts and sulfamate baths is investigated by cyclic voltammetry for different barrier layer thickness, allowing to validate the thinning conditions and to determine the appropriate deposition potential of nickel. GD-OES measurements show that low duty cycles are necessary to achieve high filling ratio of the AAO. SEM micrographs show that a smooth uniform coating is obtained when nickel is deposited in presence of additives.

  9. Novel method for joining CFRP to aluminium

    NASA Astrophysics Data System (ADS)

    Möller, F.; Thomy, C.; Vollertsen, F.; Schiebel, P.; Hoffmeister, C.; Herrmann, A. S.

    The current state of the art in joining of carbon-fibre reinforced composites (CFRP) to metals such as aluminium is - for the case of aircraft structures, e.g.- riveting or bolting. However, to reduce structural weight and improve structural performance, integral, load-bearing aluminium-CFRP-structures are desirable. To produce such structures, a novel joint configuration together with an appropriate thermal, laser-based joining process is suggested by the authors. In this paper, the joint configuration (based on CFRP-Ti-aluminium joints) and the laser beam conduction welding process will be presented, and first specimens obtained will be discussed with respect to their properties. It will be shown that the novel approach is in principle suitable to produce load-bearing CFRP-aluminium structures.

  10. Crystallization processes in aluminium hydroxide gels

    Microsoft Academic Search

    G. C. Bye; J. G. Robinson

    1964-01-01

    Summary Changes in specific surface area, interpreted in conjunction withX-ray powder diffraction and electron microscopy, have been used to follow the formation of pseudoboehmite and bayerite from amorphous aluminium hydroxide. Precipitates, essentially free from foreign ions, were prepared by the hydrolysis of aluminium s-butoxide and ageing in water, aqueous ethanol and aqueous glycerol was studied. A comparison of rates of

  11. Aluminium corrosion in room temperature molten salt

    Microsoft Academic Search

    Béatrice Garcia; Michel Armand

    2004-01-01

    Aluminium corrosion in a room temperature molten salt is studied to validate the use of a new kind of electrolyte in a lithium battery. Two solvents have been compared, the room temperature molten salt ethyl-methyl-imidazolium bis(trifluoromethane-sulfonyl)imide (EMI-TFSI), and the liquid organic solvent EC\\/DMC containing the lithium salt LiTFSI. After confirmation of high aluminium corrosion in the liquid solvent, the results

  12. Anodic polarization of aluminium in organic electrolytes

    Microsoft Academic Search

    Y. Matsuda; Y. ?Ouchi; H. Tamura

    1974-01-01

    The polarization characteristics of aluminium anodes have been studied in various organic electrolytes containing aluminium chloride. The small amount of oxide present on the metal was dissolved by an anodic pre-treatment. The charge transfer number of the overall reaction was three. The current density supported by the electrolytes decreased in the order nitromethane>acetonitrile >propylene carbonate, formamide>tetrahydrofuran. The rest potential increased

  13. Orange juice enhances aluminium absorption from antacid preparation.

    PubMed

    Fairweather-Tait, S; Hickson, K; McGaw, B; Reid, M

    1994-01-01

    Aluminium absorption from four doses of the antacid preparation 'Aludrox' when taken alone, with orange juice or with milk was compared by measuring the change in urinary aluminium following Aludrox dosage in 15 normal adults. There was an approximately 10-fold increase in 24 h urinary aluminium excretion following the Aludrox plus orange juice (232 micrograms) which was significantly higher than that following Aludrox alone (62 micrograms) (P < 0.001), but milk had no effect on aluminium absorption. The results showed that orange juice greatly enhanced aluminium absorption and should not therefore be taken in conjunction with aluminium-containing antacid preparations. PMID:8200332

  14. Mechanical properties of laser-pressure-welded joint between dissimilar galvannealed steel and pure aluminium

    Microsoft Academic Search

    Koji Nishimoto; Tomoki Harano; Yoshihiro Okumoto; Ken Atagi; Hiroo Fujii; Seiji Katayama

    2009-01-01

    Dissimilar metal joints of Zn-coated Galvannealed steel (GA steel) and commercially available pure aluminium (A1050) sheets were produced by changing the laser power and the roller pressure by the laser pressure welding method. By this method, the YAG laser beam was irradiated into a flare groove made by these dissimilar metal sheets. In addition, the laser beam was scanned at

  15. Growth of eutectic silicon from primary silicon crystals in aluminium-silicon alloys

    Microsoft Academic Search

    A. J. Criado; J. A. Martínez; R. Calabrés

    1997-01-01

    Technological interest in aluminium-silicon alloys derives, fundamentally, from their excellent moulding properties provided by the presence of silicon. In addition, they possess high thermal and electrical conductivities and good corrosion resistance. The possibility of modification of their cast structure by adding small quantities of alkaline and alkaline-earth elements makes their mechanical characteristics very competitive. Metallographic observations of the structures of

  16. [Control of residual humic acid and residual aluminium in water with enhanced coagulation].

    PubMed

    Li, Ming; Zeng, Guang-ming; Zhang, Pan-yue; Qu, Yun-Hhan; Jiang, Jian-Hong; Jiang, Ming

    2006-10-01

    Control of residual humic acid and residual aluminium in water with enhanced coagulation was investigated. The influence of various factors on the coagulation was studied, in order to reach the maximum humic acid removal and the minimum aluminium residue simultaneously. Results showed that residual humic acid was controlled below 0.04 cm(-1) and residual aluminium kept at about 0.1 mg/L in water with pH value between 6 and 6.5, the AlCl3 dosage of 0.5 x 10(-3) mol/L, under the temperature of 20 degrees C. Addition 0.01 mol/L of CaCl2 could improve the enhanced coagulation effect. Because the suspended granule concentration changes with seasons, the influence of the kaoline dosage on the humic acid removal process was studied. PMID:17256609

  17. Self-Pierce Riveting of Three Aluminium Alloy and Mild Steel Sheets

    SciTech Connect

    Mori, K.; Abe, Y.; Sakai, S. [Department of Production Systems Engineering, Toyohashi University of Technology, Tempaku, Toyohashii 441-8580 (Japan); Kato, T. [Nippon POP Rivets and Fasteners Ltd., Hosoda, Noyori-cho, Toyohashi 441-8540 (Japan)

    2010-06-15

    Three aluminium alloy and steel sheets were joined with a self-piercing rivet. Self-pierce riveting has the function of joining steel and aluminium alloys having very different melting points due to plastic joining. The requisites for joining the three sheets are the driving of the rivet leg through the middle sheet, the flaring of the rivet leg in the lower sheet and the prevention of the fracture of the lower sheet. The joinability for various combinations of the three sheets was determined. When the rivet leg is small, no driving through the middle sheet occurs, the lower sheet ruptures for a large rivet leg. In addition, 980 MPa high strength steel, mild steel and aluminium alloy sheets were joined by the self-pierce riveting.

  18. PROPRITS MAGNTIQUES DU GRENAT D'ALUMINIUM ET DE DYSPROSIUM

    E-print Network

    Paris-Sud XI, Université de

    357. PROPRIÉTÉS MAGNÉTIQUES DU GRENAT D'ALUMINIUM ET DE DYSPROSIUM II. RÉSULTATS EXPÉRIMENTAUX de grenat d'aluminium et de dysprosium en fonction soit de l'intensité, soit de l'orientation du of a spherical single crystal of dysprosium aluminium garnet has been measured at T ~ 0.37 °K as a function

  19. Aluminium and iron in the brain—prospects for chelation

    Microsoft Academic Search

    Robert R Crichton; Anne Florence; Roberta J Ward

    2002-01-01

    Aluminium and iron both accumulate in the brain in the course of ageing. We first briefly review how aluminium may interfere with iron metabolism through its interaction with iron homeostatic mechanisms. Then we present comparative data on the chelation of brain aluminium and iron in appropriate animal models of loading with the two metals. With both desferrioxamine (DFO) B and

  20. Factors which Affect the Gelling Characteristics of Aluminium Soaps

    Microsoft Academic Search

    G. A. Parry; J. E. Roberts; A. J. Taylor

    1950-01-01

    Three methods of making aluminium soaps are described, and one, the metathetic reaction between a sodium soap solution and an aluminium salt solution, is discussed in detail. The effect of variations in manufacturing technique upon the gelling characteristics of the product is considered. Recent work by various investigators on the structure of aluminium soaps is reviewed, particularly in relation to

  1. Influence of aluminium precursor on physico-chemical properties of aluminium hydroxides and oxides

    Microsoft Academic Search

    Barbara Pacewska; Olga Kluk-P?osko?ska; Dariusz Szychowski

    2007-01-01

    The paper concerns aluminium hydroxides precipitated during hydrolysis of aluminium acetate in ammonia medium, as well as\\u000a aluminium oxides obtained through their calcination at 550, 900 or 1200?C for 2 h. The following techniques were used for\\u000a analysing of obtained materials: thermal analysis, IR spectroscopy, X-ray diffraction, low-temperature nitrogen adsorption,\\u000a adsorption-desorption of benzene vapours and scanning electron microscopy.\\u000a \\u000a Freshly precipitated

  2. Aluminium Sheet Metal Forming at Low Temperatures

    NASA Astrophysics Data System (ADS)

    Schneider, R.; Heine, B.; Grant, R. J.; Zouaoui, Z.

    2015-02-01

    Low-temperature forming technology offers a new potential for forming operations of aluminium wrought alloys which show a limited formability at ambient temperatures. This paper indicates the mechanical behaviour of the commercial aluminium alloys EN AW-5182 and EN AW-6016 at low temperatures. Stress-strain relationships at different temperatures were investigated through tensile testing experiments. Flow curves were extrapolated using an adapted mathematical constitutive relationship of flow stress and strain. A device which allows cupping tests at sub-zero temperatures was specially designed and a limiting dome height was determined.

  3. Thermal formation of corundum from aluminium hydroxides prepared from various aluminium salts

    Microsoft Academic Search

    J. Temuujin; Ts Jadambaa; K. J. D. Mackenzie; P. Angerer; F. Porte; F. Riley

    2000-01-01

    Aluminium hydroxides have been precipitated from various aluminium salts and the differences in their thermal behaviour have\\u000a been investigated. Pseudoboehmite derived from the nitrate, sulfate and chloride all form ?-Al2O3 at ? 400°C but the formation of ?-A12O3 at 1200°C occurs more readily in the material derived from the sulfate. This contains a higher concentration of anionic impurities\\u000a related to

  4. Aluminium alloys in sulfuric acid Part II: Aluminium-oxygen cells

    Microsoft Academic Search

    S. Müller; F. Holzer; J. Desilvestro; O. Haas

    1996-01-01

    Aluminium alloys were tested in Al\\/O2 cells with strongly acidic electrolytes containing minor amounts of chloride ions. The faradaic efficiency, the maximum discharge capacity and the peak power of various Al\\/O2 cells were evaluated. The temperature dependence of the faradaic efficiency was measured for an Al\\/O2 cell over the temperature range from 15 to 50°C. With a zinc-containing aluminium alloy,

  5. The thermal conductivities of aluminium and platinum

    Microsoft Academic Search

    M J Duggin

    1970-01-01

    Thermal conductivity measurements have been made on platinum and aluminium over the range 380-610 K, using apparatus described previously by Duggin. The data obtained agree well with the TPRC recommended mean values. Values of the Lorenz number are calculated at several temperatures.

  6. Quenching defects in binary aluminium alloys

    Microsoft Academic Search

    G. Thomas

    1959-01-01

    Thin foils of binary aluminium alloys containing various amounts of copper, silver, zinc and magnesium in solid solution have been prepared from quenched specimens and examined by transmission electron microscopy. In all the alloys closed loops of dislocation line and complex dislocation networks were observed. The dislocation loops did not show any stacking fault contrast so they are glissile dislocations

  7. Role of inorganic additives on the ballistic performance of gun propellant formulations.

    PubMed

    Damse, R S; Sikder, A K

    2008-06-15

    This paper explores the possibility of increasing the ballistic performance of gun propellant with the addition of inorganic additives viz. aluminium and ammonium perchlorate. Compositions based on propellant NQ containing additional aluminium and ammonium perchlorate in different parts were studied theoretically and experimentally. Performance in respect of ballistic parameters, sensitivity, thermal characteristics, thermal stability and mechanical properties are evaluated and compared with that of the conventional triple base propellant NQ. Experimental data on comparative study indicate that the compositions containing aluminium and ammonium perchlorate are superior to propellant NQ in respect of energy. PMID:18206299

  8. Use of Propranolol-Magnesium Aluminium Silicate Intercalated Complexes as Drug Reservoirs in Polymeric Matrix Tablets

    PubMed Central

    Pongjanyakul, T.; Rojtanatanya, S.

    2012-01-01

    The objective of the present study was to investigate the use of propranolol–magnesium aluminium silicate intercalated complexes as drug reservoirs in hydroxypropylmethylcellulose tablets. The matrix tablets containing the complexes were prepared and characterised with respect to propranolol release and were subsequently compared with those loading propranolol or a propranolol–magnesium aluminium silicate physical mixture. Additionally, the effects of varying viscosity grades of hydroxypropyl methylcellulose, compression pressures and calcium acetate incorporation on the drug release characteristics of the complex-loaded tablets were also examined. The results showed that the complex-loaded tablets have higher tablet hardness than those containing propranolol or a physical mixture. The drug release from the complex-loaded tablets followed a zero-order release kinetic, whereas an anomalous transport was found in the propranolol or physical mixture tablets. The drug release rate of the complex tablet significantly decreased with increasing hydroxypropylmethylcellulose viscosity grade. Increase in the compression pressure caused a decrease in the drug release rate of the tablets. Furthermore, the incorporation of calcium ions could accelerate propranolol release, particularly in acidic medium, because calcium ions could be exchanged with propranolol molecules intercalated in the silicate layers of magnesium aluminium silicate. These findings suggest that propranolol-magnesium aluminium silicate intercalated complexes show strong potential for use as drug reservoirs in matrix tablets intended for modifying drug release. PMID:23626384

  9. Evaluation of certain food additives and contaminants.

    PubMed

    2013-01-01

    This report represents the conclusions of a Joint FAO/WHO Expert Committee convened to evaluate the safety of various food additives and a food contaminant with a view to concluding as to safety concerns and to preparing specifications for identity and purity. The first part of the report contains a general discussion of the principles governing the toxicological evaluation of and assessment of dietary exposure to food additives. A summary follows of the Committee's evaluations of technical, toxicological and dietary exposure data for seven food additives (advantame; glucoamylase from Trichoderma reesei expressed in Trichoderma reesei; glycerol ester of gum rosin; glycerol ester of tall oil rosin; glycerol ester of wood rosin; nisin; and octenyl succinic acid modified gum arabic) and an assessment of dietary exposure to cadmium from cocoa and cocoa products. Specifications for the following food additives were revised: annatto extracts (solvent-extracted bixin and solvent-extracted norbixin); Benzoe tonkinensis; food additives containing aluminium and/or silicon; mineral oil (medium viscosity); modified starches; paprika extract; phosphates (analytical methods for the determination of phosphorus and revision of specifications); 3-phytase from Aspergillus niger expressed in Aspergillus niger; potassium aluminium silicate; and potassium aluminium silicate-based pearlescent pigments. Annexed to the report are tables summarizing the Committee's recommendations for dietary exposures to and toxicological evaluations of the food additives and contaminant considered. PMID:24779311

  10. Mechanical Properties of Particulate Reinforced Aluminium Alloy Matrix Composite

    SciTech Connect

    Sayuti, M. [Faculty of Engineering, Malikussaleh University of Lhokseumawe, 24300 Aceh (Indonesia); Department of Mechanical and Manufacturing Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Sulaiman, S.; Baharudin, B. T. H. T.; Arifin, M. K. A. [Department of Mechanical and Manufacturing Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Suraya, S.; Vijayaram, T. R.

    2011-01-17

    This paper discusses the mechanical properties of Titanium Carbide (TiC) particulate reinforced aluminium-silicon alloy matrix composite. TiC particulate reinforced LM6 alloy matrix composites were fabricated by carbon dioxide sand molding process with different particulate weight fraction. Tensile strength, hardness and microstructure studies were conducted to determine the maximum load, tensile strength, modulus of elasticity and fracture surface analysis have been performed to characterize the morphological aspects of the test samples after tensile testing. Hardness values are measured for the TiC reinforced LM6 alloy composites and it has been found that it gradually increases with increased addition of the reinforcement phase. The tensile strength of the composites increased with the increase percentage of TiC particulate.

  11. Feet sunk in molten aluminium: The burn and its prevention.

    PubMed

    Alonso-Peña, David; Arnáiz-García, María Elena; Valero-Gasalla, Javier Luis; Arnáiz-García, Ana María; Campillo-Campaña, Ramón; Alonso-Peña, Javier; González-Santos, Jose María; Fernández-Díaz, Alaska Leonor; Arnáiz, Javier

    2015-08-01

    Nowadays, despite improvements in safety rules and inspections in the metal industry, foundry workers are not free from burn accidents. Injuries caused by molten metals include burns secondary to molten iron, aluminium, zinc, copper, brass, bronze, manganese, lead and steel. Molten aluminium is one of the most common causative agents of burns (60%); however, only a few publications exist concerning injuries from molten aluminium. The main mechanisms of lesion from molten aluminium include direct contact of the molten metal with the skin or through safety apparel, or when the metal splash burns through the pants and rolls downward along the leg. Herein, we report three cases of deep dermal burns after 'soaking' the foot in liquid aluminium and its evolutive features. This paper aims to show our experience in the management of burns due to molten aluminium. We describe the current management principles and the key features of injury prevention. PMID:25687835

  12. An ultrafast rechargeable aluminium-ion battery.

    PubMed

    Lin, Meng-Chang; Gong, Ming; Lu, Bingan; Wu, Yingpeng; Wang, Di-Yan; Guan, Mingyun; Angell, Michael; Chen, Changxin; Yang, Jiang; Hwang, Bing-Joe; Dai, Hongjie

    2015-04-16

    The development of new rechargeable battery systems could fuel various energy applications, from personal electronics to grid storage. Rechargeable aluminium-based batteries offer the possibilities of low cost and low flammability, together with three-electron-redox properties leading to high capacity. However, research efforts over the past 30 years have encountered numerous problems, such as cathode material disintegration, low cell discharge voltage (about 0.55 volts; ref. 5), capacitive behaviour without discharge voltage plateaus (1.1-0.2 volts or 1.8-0.8 volts) and insufficient cycle life (less than 100 cycles) with rapid capacity decay (by 26-85 per cent over 100 cycles). Here we present a rechargeable aluminium battery with high-rate capability that uses an aluminium metal anode and a three-dimensional graphitic-foam cathode. The battery operates through the electrochemical deposition and dissolution of aluminium at the anode, and intercalation/de-intercalation of chloroaluminate anions in the graphite, using a non-flammable ionic liquid electrolyte. The cell exhibits well-defined discharge voltage plateaus near 2 volts, a specific capacity of about 70 mA h g(-1) and a Coulombic efficiency of approximately 98 per cent. The cathode was found to enable fast anion diffusion and intercalation, affording charging times of around one minute with a current density of ~4,000 mA g(-1) (equivalent to ~3,000 W kg(-1)), and to withstand more than 7,500 cycles without capacity decay. PMID:25849777

  13. CVV Auger line shapes in aluminium

    NASA Astrophysics Data System (ADS)

    Contini, V.; Presilla, C.; Sacchetti, F.

    1989-05-01

    Aluminium L 23 VV and KVV Auger spectra are compared for the first time. In spite of the differences in kinetic energy of the escaping electrons and of the core-holes, the two spectra look very similar suggesting that surface effects do not contribute much to the Auger transition. Moreover in both spectra it is visible a high energy structure which is interpreted as an intrinsic plasmon-grain satellite due to the core-hole relaxation.

  14. The Thermal Decomposition of Lithium Aluminium Hydride

    Microsoft Academic Search

    W. E. Garner; E. W. Haycock

    1952-01-01

    Lithium aluminium hydride on heating decomposes in three stages: (a) an initial surface reaction during the induction period, followed by (b) an interface reaction giving an S-shaped pressure against time curve, corresponding to LiAlH4rightharpoonup LiAlH2 + H2, and (c) a slow process during which a third hydrogen atom is liberated. The initial reaction is rapid at first and then slows

  15. Analytical electron microscopy of aluminium alloys

    Microsoft Academic Search

    T R Ramachandran; D C Houghton; J D Embury

    1984-01-01

    X-ray microanalysis and electron energy loss spectroscopy of thin foils constitute the important techniques of high resolution\\u000a chemical analysis using the electron microscope. The technique of x-ray microanalysis is discussed in this paper with particular\\u000a emphasis on the study of aluminium alloys using a dedicated scanning transmission electron microscope (stem).\\u000a \\u000a The principle of determining chemical composition from observed x-ray peak

  16. Warm Deep Drawing of Aluminium Sheet

    Microsoft Academic Search

    P. J. Bolt; R. J. Werkhoven; Boogaard van den A. H

    2003-01-01

    Aluminium sheet drawing processes can be improved by manipulating local flow behaviour\\u000aby means of elevated temperatures and temperature gradients in the tooling. Forming tests\\u000ashowed that a substantial improvement is possible not only for 5xxx but also for 6xxx series\\u000aalloys. Finite element method simulations can be a powerful tool for the design of warm\\u000aforming processes and tooling.

  17. Citric acid as corrosion inhibitor for aluminium pigment

    Microsoft Academic Search

    B. Müller

    2004-01-01

    Aluminium pigments corrode in aqueous alkaline media (e.g., water-borne paints) with the evolution of hydrogen.The hydrogen corrosion of aluminium pigment can be inhibited by the chelating agent citric acid, which is a renewable raw material and absolutely non-toxic. At pH 8 more hydrogen is evolved as at pH 10 which can be explained with the isoelectric point of aluminium oxide

  18. Inhalation exposure in secondary aluminium smelting.

    PubMed

    Healy, J; Bradley, S D; Northage, C; Scobbie, E

    2001-04-01

    Inhalation exposure at seven UK secondary aluminium smelters was investigated to quantify the main exposures and identify their sources. The substances monitored were gases (carbon monoxide, hydrogen sulphide and nitrogen dioxide), total inhalable dust, metals, ammonia, polycyclic aromatic hydrocarbons (PAHs), particulate fluoride salts and acids. The results showed that people were exposed to a range of workplace air pollutants. Personal exposure results for total inhalable dust were between 700 and 5600 microg x m(-3) and the maximum personal exposure result for particulate fluoride salts was 690 microg x m(-3) (as F). The maximum aluminium, total PAH and lead personal exposure results were 900, 19 and 18 microg x m(-3) respectively. The average proportion of aluminium in total inhalable dust samples was 13% and rotary furnace processes generated the most dust. Particulate fluoride salt exposure was more widespread than hydrofluoric acid exposure. The source of the salt exposure was fluoride containing fluxes. The lead exposure source was lead solder contamination in the furnace charge. PMID:11295145

  19. Aluminium-aluminium nitride composites fabricated by melt infiltration under pressure

    PubMed

    Chedru; Vicens; Chermant; Mordike

    1999-11-01

    Aluminium-matrix composites containing approximately 55 vol.% AlN particles were fabricated by melt infiltration of aluminium into an AlN preform under a pressure of up to 130 MPa. Two different AlN powders (H.C. Starck, Goslar, Germany, and ESK, Elektroschmelzwerk, Kempten, Germany) and four types of aluminium alloy (2024, 1070, 6060 and 5754) were used. The initial AlN powders were characterized by scanning electron microscopy. The composites were studied by light microscopy, scanning and transmission electron microscopies and energy-dispersive X-ray spectroscopy. Particle-matrix interfaces were observed using high-resolution electron microscopy. As a result of the melt infiltration process, the composites are very dense and the microstructure shows a homogeneous distribution of the reinforcement. The interfaces are clean with very little porosity. Some Al2Cu precipitates were observed in the 2024 matrix. PMID:10540263

  20. Effects of aluminium surface morphology and chemical modification on wettability

    NASA Astrophysics Data System (ADS)

    Rahimi, M.; Fojan, P.; Gurevich, L.; Afshari, A.

    2014-03-01

    Aluminium alloys are some of the predominant metals in industrial applications such as production of heat exchangers, heat pumps. They have high heat conductivity coupled with a low specific weight. In cold working conditions, there is a risk of frost formation on the surface of aluminium in the presence of water vapour, which can lead to the deterioration of equipment performance. This work addresses the methods of surface modification of aluminium and their effect of the underlying surface morphology and wettability, which are the important parameters for frost formation. Three groups of real-life aluminium surfaces of different morphology: unpolished aluminium, polished aluminium, and aluminium foil, were subjected to surface modification procedures which involved the formation of a layer of hydrophilic hyperbranched polyethyleneglycol via in situ polymerization, molecular vapour deposition of a monolayer of fluorinated silane, and a combination of those. The effect of these surface modification techniques on roughness and wettability of the aluminium surfaces was elucidated by ellipsometry, contact angle measurements and atomic force microscopy. We demonstrated that by employing different types of surface modifications the contact angle of water droplets on aluminium samples can be varied from 12° to more than 120°. A crossover from Cassie-Baxter to Wenzel regime upon changing the surface roughness was also observed.

  1. The study of aluminium anodes for high power density Al\\/air batteries with brine electrolytes

    Microsoft Academic Search

    Maria Nestoridi; Derek Pletcher; Robert J. K. Wood; Shuncai Wang; Richard L. Jones; Keith R. Stokes; Ian Wilcock

    2008-01-01

    Aluminium alloys containing small additions of both tin (?0.1wt%) and gallium (?0.05wt%) are shown to dissolve anodically at high rates in sodium chloride media at room temperatures; current densities >0.2Acm?2 can be obtained at potentials close to the open circuit potential, ??1500mV versus SCE. The tin exists in the alloys as a second phase, typically as ?1?m inclusions (precipitates) distributed

  2. Aluminium oxide nanowires synthesis from high purity aluminium films via two-step anodization

    NASA Astrophysics Data System (ADS)

    Nazemi, Azadeh; Najafian, Ahmad; Seyed Sadjadi, Seyed Abolfazl

    2015-05-01

    Anodic Aluminium Oxide (AAO) templates were prepared via two-step anodization by using high purity aluminium films. After second anodization, AAO templates were treated under pore-widening process, by being immersed in 5 wt% phosphoric acid. In this study, effect of pore-widening time on structure and pore diameters of AAO templates were investigated and controlling the pore-widening time, alumina nanowires were fabricated. Different techniques, such as Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), and Energy Dispersive Spectrum (EDS) were employed to study the structure of AAO templates and alumina nanowires.

  3. Microstructure and strength of Si-Ti-C-O, fibre-reinforced aluminium and aluminium alloys

    Microsoft Academic Search

    T. B. Williams; D. Shindo; E. Aoyagi; M. Hirabayashi; Y. Waku; M. Suzuki

    1991-01-01

    Microstructures of Si-Ti-C-O fibre-reinforced aluminium and aluminium alloys were investigated by scanning electron microscopy,\\u000a and both conventional and analytical transmission electron microscopy. In the latter samples, some inclusions were observed\\u000a between the matrix and the fibres. From the electron diffraction, high resolution microscopy and compositional analysis by\\u000a energy-dispersive X-ray, the inclusions were identified as the ?-Al-Si-Fe phase. Since the longitudinal

  4. Amazing Addition!!

    NSDL National Science Digital Library

    Ms. Staggs

    2008-04-01

    Math can be fun! Practice your addtion facts in one of these amazing games! Go on a mission with math! -- Addition Mission Count your apples! -- Apple Addition Be a math teacher! -- Chalkboard Addition ...

  5. Influence of nanoporous structure on mechanical strength of aluminium and aluminium alloy adhesive structural joints

    Microsoft Academic Search

    C. Spadaro; C. Dispenza; C. Sunseri

    2006-01-01

    The influence of surface treatments on the mechanical strength of adhesive joints was investigated. The attention was focused on AA2024 alloy because it is extensively used in both the automotive and aerospace industries. Adhesive joints fabricated with pure aluminium were also investigated in order to evidence possible differences in the surface features after identical treatments. Before joining with a commercial

  6. Haemodialysis related osteomalacia: a staining method to demonstrate aluminium

    Microsoft Academic Search

    Malcolm RC Buchanan; Benno U Ihle; Cheryl M Dunn

    1981-01-01

    A slight modification in tissue processing and staining technique enables a previously described method for staining aluminium to be used to demonstrate aluminium in osteomalacia associated with haemodialysis. The stain appears to be accurate in diagnosing this condition and may assist in establishing the diagnosis before severe osteomalacia develops.

  7. Aluminium salt slag characterization and utilization--a review.

    PubMed

    Tsakiridis, P E

    2012-05-30

    Aluminium salt slag (also known as aluminium salt cake), which is produced by the secondary aluminium industry, is formed during aluminium scrap/dross melting and contains 15-30% aluminium oxide, 30-55% sodium chloride, 15-30% potassium chloride, 5-7% metallic aluminium and impurities (carbides, nitrides, sulphides and phosphides). Depending on the raw mix the amount of salt slag produced per tonne of secondary aluminium ranges from 200 to 500 kg. As salt slag has been classified as toxic and hazardous waste, it should be managed in compliance with the current legislation. Its landfill disposal is forbidden in most of the European countries and it should be recycled and processed in a proper way by taking the environmental impact into consideration. This paper presents a review of the aluminium salt slag chemical and mineralogical characteristics, as well as various processes for metal recovery, recycling of sodium and potassium chlorides content back to the smelting process and preparation of value added products from the final non metallic residue. PMID:22480708

  8. Growth of porous anodic films on FVS0812 aluminium alloy

    Microsoft Academic Search

    J. A. Sykes; G. E. Thompson; P. Skeldon; D. Mayo

    1998-01-01

    The formation of porous anodic films on FVS0812 aluminium alloy has been examined by transmission electron microscopy in order to elucidate the processes of film growth. A complex morphology of film material is revealed containing relatively tortuous, branched and terminated porosity and relatively large cavities. The morphology is associated with the differing anodic oxidation behaviour of the aluminium matrix and

  9. Ionic fluids in lubrication of aluminium-steel contacts. Surface and tribochemical interactions

    NASA Astrophysics Data System (ADS)

    Jimenez Ballesta, Ana Eva

    Room-temperature ionic liquids (ILs) are high performance fluids with a wide thermal stability range. They are being studied as new lubricants in a variety of sliding contacts. One of their more interesting tribological applications is that of steel-aluminium lubrication. In this work we study the influence of the lateral alkyl chain length and of the anion on the lubricating ability of six imidazolium ILs, a pyridinium and a phosphonium derivative. For first time, these ILs have been studied as neat lubricants and as 1wt.% base oil additives in variable conditions of velocity, load and temperature in pin-on-disk tests for AISI 52100 steel-ASTM 2011 aluminium contacts. In this work we present the first study of ILs as lubricants under extreme temperature conditions. The tribological performance of ILs has been compared with that of a mineral oil and of a synthetic ester. Under these conditions, ILs show lower friction and wear values than conventional oils at all temperatures. As 1wt.% additives, the conditions of optimum lubrication and the transitions between regimes and lubrication mechanisms have been determined. We have also studied the performance of ILs as 1wt.% additives of the synthetic oil. A relationship between additive polarity and wear index has been established. If the more soluble phosphonium IL additive is used, no friction or wear reduction takes place due to competition between solvation and adsorption processes. Electronic microscopy (SEM), energy dispersive (EDS) and X-ray photoelectron (XPS) spectroscopies have been used to study the wear mechanisms and tribochemical processes that take place in the contact. Finally, we have studied the performance of three aluminium alloys in corrosion and erosion-corrosion tests. In immersion tests with free-water ILs, the aluminium alloy 2011 shows a good resistance to corrosion, but dilution of 1-ethyl, 3-methylimidazolium tetrafluoroborate in water produces the hydrolysis of the anion and the corrosion of the aluminium alloy. In erosion-corrosion tests, although the three alloys show a good corrosion resistance (?0.2 mm/year) their performance is related to the copper content, with higher rates at higher copper percentages. The surfaces have been characterized by SEM, EDS, XPS and X-ray diffraction (XRD).

  10. Deviatoric response of the aluminium alloy, 5083

    NASA Astrophysics Data System (ADS)

    Appleby-Thomas, Gareth; Hazell, Paul; Millett, Jeremy; Bourne, Neil

    2009-06-01

    Aluminium alloys such as 5083 are established light weight armour materials. As such, the shock response of these materials is of great importance. The shear strength of a material under shock loading provides an insight into its ballistic performance. In this investigation embedded manganin stress gauges have been employed to measure both the longitudinal and lateral components of stress during plate impact experiments over a range of impact stresses. In turn, these results were used to determine the shear strength and to investigate the time dependence of lateral stress behind the shock front to give an indication of material response.

  11. Albumin adsorption on to aluminium oxide and polyurethane surfaces.

    PubMed

    Sharma, C P; Sunny, M C

    1990-05-01

    The changes in protein adsorption onto aluminium surfaces coated with different thicknesses of oxide layers were examined. The oxide layers on aluminium substrates were derived by the anodizing technique. Protein adsorption studies were conducted using 125I-labelled albumin and the amount of albumin adsorbed was estimated with the help of a gamma counter. An increase in albumin adsorption was observed on oxide layer coated aluminium surfaces. The effect of anti-Hageman factor on albumin and fibrinogen adsorption on to bare aluminium, oxide layer coated aluminium and bare polyether urethane urea surfaces was also investigated. It was observed that the presence of anti-Hageman factor increased the adsorption of albumin and fibrinogen on to all these substrates. PMID:2383620

  12. Usage of neural network to predict aluminium oxide layer thickness.

    PubMed

    Michal, Peter; Vagaská, Alena; Gombár, Miroslav; Kmec, Ján; Spišák, Emil; Ku?erka, Daniel

    2015-01-01

    This paper shows an influence of chemical composition of used electrolyte, such as amount of sulphuric acid in electrolyte, amount of aluminium cations in electrolyte and amount of oxalic acid in electrolyte, and operating parameters of process of anodic oxidation of aluminium such as the temperature of electrolyte, anodizing time, and voltage applied during anodizing process. The paper shows the influence of those parameters on the resulting thickness of aluminium oxide layer. The impact of these variables is shown by using central composite design of experiment for six factors (amount of sulphuric acid, amount of oxalic acid, amount of aluminium cations, electrolyte temperature, anodizing time, and applied voltage) and by usage of the cubic neural unit with Levenberg-Marquardt algorithm during the results evaluation. The paper also deals with current densities of 1 A · dm(-2) and 3 A · dm(-2) for creating aluminium oxide layer. PMID:25922850

  13. Atmospheric plasma torch treatment of aluminium: Improving wettability with silanes

    NASA Astrophysics Data System (ADS)

    Díaz-Benito, B.; Velasco, F.

    2013-12-01

    This study investigates the effect of atmospheric pressure plasma torch (APPT) treatments on the surface of aluminium alloys. The influence of torch-to-sample distance, speed of treatment and ageing time is analyzed in terms of contact angles and surface energy. Results show that APPT treatment strongly increases the surface energy and wettability of aluminium surfaces. This is related to the formation of polar groups, as Fourier transform infrared (FTIR) spectroscopy has confirmed. In all conditions, hydrophobic recovery of aluminium surfaces takes place. Finally, the compatibility of the APPT treated aluminium substrate with ?-methacryloxypropyltrimethoxysilane (MPS) has been evaluated through adhesion work and spread tension, showing that it is possible to achieve a spontaneous wetting process of silane on aluminium.

  14. Usage of Neural Network to Predict Aluminium Oxide Layer Thickness

    PubMed Central

    Michal, Peter; Vagaská, Alena; Gombár, Miroslav; Kmec, Ján; Spišák, Emil; Ku?erka, Daniel

    2015-01-01

    This paper shows an influence of chemical composition of used electrolyte, such as amount of sulphuric acid in electrolyte, amount of aluminium cations in electrolyte and amount of oxalic acid in electrolyte, and operating parameters of process of anodic oxidation of aluminium such as the temperature of electrolyte, anodizing time, and voltage applied during anodizing process. The paper shows the influence of those parameters on the resulting thickness of aluminium oxide layer. The impact of these variables is shown by using central composite design of experiment for six factors (amount of sulphuric acid, amount of oxalic acid, amount of aluminium cations, electrolyte temperature, anodizing time, and applied voltage) and by usage of the cubic neural unit with Levenberg-Marquardt algorithm during the results evaluation. The paper also deals with current densities of 1?A·dm?2 and 3?A·dm?2 for creating aluminium oxide layer. PMID:25922850

  15. Volatilisation and oxidation of aluminium scraps fed into incineration furnaces

    SciTech Connect

    Biganzoli, Laura, E-mail: laura.biganzoli@mail.polimi.it [Politecnico di Milano, Piazza L. Da Vinci 32, 20133 Milano (Italy); Gorla, Leopoldo; Nessi, Simone; Grosso, Mario [Politecnico di Milano, Piazza L. Da Vinci 32, 20133 Milano (Italy)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Aluminium packaging partitioning in MSW incineration residues is evaluated. Black-Right-Pointing-Pointer The amount of aluminium packaging recoverable from the bottom ashes is evaluated. Black-Right-Pointing-Pointer Aluminium packaging oxidation rate in the residues of MSW incineration is evaluated. Black-Right-Pointing-Pointer 80% of aluminium cans, 51% of trays and 27% of foils can be recovered from bottom ashes. - Abstract: Ferrous and non-ferrous metal scraps are increasingly recovered from municipal solid waste incineration bottom ash and used in the production of secondary steel and aluminium. However, during the incineration process, metal scraps contained in the waste undergo volatilisation and oxidation processes, which determine a loss of their recoverable mass. The present paper evaluates the behaviour of different types of aluminium packaging materials in a full-scale waste to energy plant during standard operation. Their partitioning and oxidation level in the residues of the incineration process are evaluated, together with the amount of potentially recoverable aluminium. About 80% of post-consumer cans, 51% of trays and 27% of foils can be recovered through an advanced treatment of bottom ash combined with a melting process in the saline furnace for the production of secondary aluminium. The residual amount of aluminium concentrates in the fly ash or in the fine fraction of the bottom ash and its recovery is virtually impossible using the current eddy current separation technology. The average oxidation levels of the aluminium in the residues of the incineration process is equal to 9.2% for cans, 17.4% for trays and 58.8% for foils. The differences between the tested packaging materials are related to their thickness, mechanical strength and to the alloy.

  16. EFFECT OF SHOT PEENING ON FATIGUE PERFORMANCE OF ADVANCED ALUMINIUM ALLOYS AND ALUMINIUM BASED METAL MATRIX COMPOSITES

    Microsoft Academic Search

    Future airframe designs may incorporate the lightweight lithium-containing aluminium alloys and silicon carbide reinforced aluminium alloys which offer enhanced specific stiffness and strength. The present research set out to investigate the influence of shot peening on the fatigue performance of the monolithic and composite materials under rotating bend loading conditions with a stress ratio R = -1. The metal matrix

  17. DISLOCATION DYNAMICS IN ALUMINIUM AND IN ALUMINIUM-COPPER ALLOYS: A NUCLEAR MAGNETIC RESONANCE AND TRANSMISSION ELECTRON MICROSCOPIC STUDY

    Microsoft Academic Search

    W. TAMLER; M. ALSEM; M. DE HOSSON

    Pulsed nuclear magnetic resonance techniques as well as transmission electron microscopy have been applied to study dislocation motion in ultrapure aluminium and aluminium+opper alloys (Al:xCu with x,, = 1 at.%). The spin-lattice relaxation rate in the rotating frame. 7,' of \\

  18. Amazing Addition!!

    NSDL National Science Digital Library

    Ms. Bolton

    2009-04-22

    I want you to practice your awesome addition skills on the websites below. I know you will do beautifully! Start by going to this website first: Addition Fun!!! Once you finish that website you may continue onto this website: Alien Addition If you have extra time play Around the World Addition: Once you have clicked on the link, click on the button for addition.After that you can choose to play on easy or ...

  19. Modelling of Laser Spall Experiments on Aluminium

    NASA Astrophysics Data System (ADS)

    Robinson, C. M.

    2001-06-01

    Recently several shots have been fired on the AWE HELEN laser in order to study the spall of aluminium at high strain rates. In the first shot a radiograph was taken which showed a spall layer had formed. Further shots were fired and the free surface velocity of the aluminium was measured using velocity interferometry. Five of these shots showed spall had occurred. This paper attempts to model these shots using the Johnson spall model. Previously determined spall parameters(Giles, A.R. Maw, J.R. In Shock Compression of Condensed Matter 1997. Eds. Schmidt, S.C. Dandekar, D.P. Forbes, J.W. (The American Institute of Physics, 1998)) are found not to model the spall well, so new spall parameters are determined that match the laser results. The model is then applied to some published low strain rate plate impact experiments(Kanel, G.I. Razorenov, S.V. Utkin, A.V. Baumung, K. Shock Wave Profile Data. Scientific Association IVTAN of Russian Academy of Sciences, 1996), and it is found that the original spall parameters provide the best fit. The mechanism that causes the spall layer to form is different for the two sets of parameters.

  20. Study on aluminium-based single films.

    PubMed

    Vinod Kumar, G S; García-Moreno, F; Babcsán, N; Brothers, A H; Murty, B S; Banhart, J

    2007-12-28

    In the present paper the authors studied isolated metallic films made from the same material used for making metallic foams, and then characterised their properties. Metal films were made from a liquid aluminium alloy reinforced with ceramic particles of known concentration. Melts without such particles were also investigated. It is shown that stable films could not be made from Al-Si alloy having no particles, and just extremely thin and fragile films could be made from commercially-pure Al. In contrast, aluminium alloys containing particles such as SiC and TiB(2) allowed pulling thin, stable films, which did not rupture. Significant thinning of films was observed when the particle concentration in the melt decreased. By in situ X-ray monitoring of liquid films during pulling, film thickness and drainage effects within the liquid film could be studied. The morphology and microstructure of films was characterised after solidification. Our work shows that the question of how foams are stabilised can be studied using a simplified system such as a film, instead of having to deal with the multitude of different structural elements present in a foam. PMID:18060172

  1. Food additives

    PubMed Central

    Spencer, Michael

    1974-01-01

    Food additives are discussed from the food technology point of view. The reasons for their use are summarized: (1) to protect food from chemical and microbiological attack; (2) to even out seasonal supplies; (3) to improve their eating quality; (4) to improve their nutritional value. The various types of food additives are considered, e.g. colours, flavours, emulsifiers, bread and flour additives, preservatives, and nutritional additives. The paper concludes with consideration of those circumstances in which the use of additives is (a) justified and (b) unjustified. PMID:4467857

  2. Aluminium recovery vs. hydrogen production as resource recovery options for fine MSWI bottom ash fraction.

    PubMed

    Biganzoli, Laura; Ilyas, Aamir; Praagh, Martijn van; Persson, Kenneth M; Grosso, Mario

    2013-05-01

    Waste incineration bottom ash fine fraction contains a significant amount of aluminium, but previous works have shown that current recovery options based on standard on-step Eddy Current Separation (ECS) have limited efficiency. In this paper, we evaluated the improvement in the efficiency of ECS by using an additional step of crushing and sieving. The efficiency of metallic Al recovery was quantified by measuring hydrogen gas production. The ash samples were also tested for total aluminium content with X-ray fluorescence spectroscopy (XRF). As an alternative to material recovery, we also investigated the possibility to convert residual metallic Al into useful energy, promoting H2 gas production by reacting metallic Al with water at high pH. The results show that the total aluminium concentration in the <4 mm bottom ash fraction is on average 8% of the weight of the dry ash, with less than 15% of it being present in the metallic form. Of this latter, only 21% can be potentially recovered with ECS combined with crushing and sieving stages and subsequently recycled. For hydrogen production, using 10MNaOH at 1L/S ratio results in the release of 6-11l of H2 gas for each kilogram of fine dry ash, equivalent to an energy potential of 118 kJ. PMID:23453355

  3. Formation of aluminium oxynitride by carbothermal reduction of aluminium oxide in nitrogen

    Microsoft Academic Search

    Moshe Ish-Shalom; Wright-Patterson AFB

    1982-01-01

    The preparation of cubic aluminium oxynitride with spinel-type structure by reacting mixtures of A1203 and A1N at temperatures above 1700 ° C has been reported by Lejus in 1962 [1] and 1964 [2] and more recently by McCautey and Corbin [3]. The latter called the material ALON and described the phase relationships in the range of compositions of about 20

  4. [Post-vaccination granuloma due to aluminium hydroxide].

    PubMed

    Bordet, A L; Michenet, P; Cohen, C; Arbion, F; Ekindi, N; Bonneau, C; Kerdraon, R; Coville, M

    2001-04-01

    Post-vaccination granulomas a well-known reaction due to aluminium adsorbed vaccines. We report three cases of children who developed subcutaneous nodules at the site of a previous injection of Tetracoq*vaccine (tetanus, diphtheria, Bordetella pertussis, poliovirus). Histologically, the lesions were characterized by a necrotizing granulomatous reaction with eosinophilic crystalline material. This material stained positively with the solochrome cyanine stain and was pink-purple. This aluminium stain enabled diagnosis of post-immunization injection-site reaction due to aluminium. PMID:11373585

  5. Polymer additives

    SciTech Connect

    Carraher, C. [Florida Atlantic Univ., Boca Raton, FL (United States); Swift, G. [Rohm and Haas Co., Spring House, PA (United States)

    1993-12-31

    Polymers, because of the unique properties offered by them, are being employed to larger extents as additives. Polymeric additives may offer incentives such as cost, performance and unique properties. Polymeric additives have been used for years as viscosity modifiers in motor oils, plastisols, antifoaming agents and fillers. New uses are quickly emerging as permanent coloring agent, antibacterial agents and as delivery aids for metals and metal oxides.

  6. Plasma ion assisted deposition of aluminium oxide and aluminium oxifluoride layers for applications in the ultraviolet spectral range

    NASA Astrophysics Data System (ADS)

    Stenzel, O.; Gäbler, D.; Wilbrandt, S.; Kaiser, N.; Steffen, H.; Ohl, A.

    2011-09-01

    We present extended experimental material about optical and mechanical properties as well as the water content of aluminium oxide films, deposited by plasma ion assisted electron beam evaporation. A clear correlation between these experimental data is established and understood as being affected by the different degree of the porosity of the films. When adding fluorine as a reactive gas during deposition, aluminium oxifluoride layers can be obtained that appear nearly free of water, and combine UV-transparency with higher UV refractive indices than porous aluminium oxide layers.

  7. Crystalline silicon core fibres from aluminium core preforms.

    PubMed

    Hou, Chong; Jia, Xiaoting; Wei, Lei; Tan, Swee-Ching; Zhao, Xin; Joannopoulos, John D; Fink, Yoel

    2015-01-01

    Traditional fibre-optic drawing involves a thermally mediated geometric scaling where both the fibre materials and their relative positions are identical to those found in the fibre preform. To date, all thermally drawn fibres are limited to the preform composition and geometry. Here, we fabricate a metre-long crystalline silicon-core, silica-cladded fibre from a preform that does not contain any elemental silicon. An aluminium rod is inserted into a macroscopic silica tube and then thermally drawn. The aluminium atoms initially in the core reduce the silica, to produce silicon atoms and aluminium oxide molecules. The silicon atoms diffuse into the core, forming a large phase-separated molten silicon domain that is drawn into the crystalline silicon core fibre. The ability to produce crystalline silicon core fibre out of inexpensive aluminium and silica could pave the way for a simple and scalable method of incorporating silicon-based electronics and photonics into fibres. PMID:25697119

  8. The management of Frey's syndrome with aluminium chloride hexahydrate antiperspirant.

    PubMed Central

    Black, M. J.; Gunn, A.

    1990-01-01

    Nine patients suffering from gustatory sweating (Frey's syndrome) following parotidectomy have been treated by topical applications of aluminium chloride hexahydrate. Treatment has successfully controlled gustatory sweating using application intervals varying from 1 to 50 days. Images Figure 1 PMID:2301903

  9. Sulfone-based electrolytes for aluminium rechargeable batteries.

    PubMed

    Nakayama, Yuri; Senda, Yui; Kawasaki, Hideki; Koshitani, Naoki; Hosoi, Shizuka; Kudo, Yoshihiro; Morioka, Hiroyuki; Nagamine, Masayuki

    2015-02-28

    Electrolyte is a key material for success in the research and development of next-generation rechargeable batteries. Aluminium rechargeable batteries that use aluminium (Al) metals as anode materials are attractive candidates for next-generation batteries, though they have not been developed yet due to the lack of practically useful electrolytes. Here we present, for the first time, non-corrosive reversible Al electrolytes working at room temperature. The electrolytes are composed of aluminium chlorides, dialkylsulfones, and dilutants, which are realized by the identification of electrochemically active Al species, the study of sulfone dependences, the effects of aluminium chloride concentrations, dilutions and their optimizations. The characteristic feature of these materials is the lower chloride concentrations in the solutions than those in the conventional Al electrolytes, which allows us to use the Al metal anodes without corrosions. We anticipate that the sulfone-based electrolytes will open the doors for the research and development of Al rechargeable batteries. PMID:25627398

  10. Aluminium powder metallurgy technology for high-strength applications

    Microsoft Academic Search

    J. R. Pickens

    1981-01-01

    A literature survey of aluminium powder metallurgy (PM) for high-strength applications was undertaken. Improvements in aluminium—base alloys made via ingot metallurgy (IM) are reaching the point of diminishing returns. PM offers an alternative technology, capable of producing alloys having improved fatigue, corrosion, and stress-corrosion resistance, as well as improved strength and toughness at room or elevated temperatures. The steps involved

  11. Characterization of rapidly solidified aluminium-silicon alloy

    Microsoft Academic Search

    S. Das; A. H. Yegneswaran; P. K. Rohatgi

    1987-01-01

    A metallographic investigation of as-cast LM-13 aluminium-silicon alloy, solidified at different cooling rates (using permanent moulds or a single-roll melt spinner), is presented with special reference to the modification of eutectic silicon. and the refinement of primary aluminium. The refinement of microstructure with the increase in cooling rate is mainly attributed to the limited growth kinetics of the nucleated phase

  12. Study of aluminium and lead in some traditional Omani dishes.

    PubMed

    El Tawila, M; Al Awfy, S; Al Asfoor, D

    1996-01-01

    Because of the recent interest on the aluminium content of foods cooked in aluminium saucepans and the association between aluminium and lead and many toxic symptoms and disease, information about the source of exposure of man to these metals specially from food and drinks are required. Thirty four of the most commonly consumed Omani dishes were analyzed for their aluminium and lead content, in order to determine the level of contamination and to estimate the approximate oral intake of each metal. The level of aluminium in the studied dishes was in the range between 0.98 and 16.53 mg/kg with a mean 5.4 mg/kg. The highest level of aluminium was found in fish dishes (9.03 mg/kg) and meat and poultry dishes (7.66 mg/kg). The effect of using aluminium pans on the metal level was also studied in some foods. The effect varies from slight increase in case of frying or cooking of fish to a significant increase in case of baking rakal bread on aluminium flat pan. The level of lead in the studied dishes ranged between 0.026 and 1.75 mg/kg with a mean of 0.32 mg/kg. Salted fish contained the highest level of lead (0.57 mg/kg). The approximate daily intake, calculated on the base of the serving quantities, was found to be within the acceptable daily or weekly intake recommended for each metal. PMID:17214194

  13. Microstructure, tensile deformation and fracture behaviour of aluminium alloy 7055

    Microsoft Academic Search

    T. S Srivatsan; S. SRIRAM; D Veeraraghavan; V. K Vasudevan

    1997-01-01

    The microstructure, tensile deformation and fracture behaviour of aluminium alloy 7055 were studied. Detailed optical and\\u000a electron microscopy observations were made to analyse the as-received microstructure of the alloy. Detailed transmission electron\\u000a microscopy observations revealed the principal strengthening precipitates to be the hexagonal disc-shaped ?? phase of size\\u000a 2 mm20 mm and fully coherent with the aluminium alloy matrix, the

  14. Viscous pressure bulging of aluminium alloy sheet at warm temperatures

    Microsoft Academic Search

    Jianguang Liu; Qiucai Peng; Yan Liu; Zhongjin Wang

    2007-01-01

    Improving the formability of aluminium alloy sheet metal by using warm or elevated temperature has become a valid approach.\\u000a In this paper, viscous pressure bulging (VPB) at warm temperature is proposed. The coupled thermo-mechanical finite element\\u000a method and experimental method were used to investigate the VPB of aluminium alloy AA3003 at warm temperature. The temperature\\u000a distributions of sheet metal and

  15. Characterization and structure of precipitates in 6xxx Aluminium Alloys

    NASA Astrophysics Data System (ADS)

    Holmestad, Randi; Bjørge, Ruben; Ehlers, Flemming J. H.; Torsæter, Malin; Marioara, Calin D.; Andersen, Sigmund J.

    2012-07-01

    Solute atom nanoscale precipitates are responsible for the favourable mechanical properties of heat treatable aluminium alloys such as Al-Mg-Si (6xxx). The shape, structure and strengthening properties of age-hardening precipitates depend on alloy composition and thermo-mechanical history. We seek an improved understanding of the physics related to nucleation and precipitation on the atomistic level in these alloys. Once these mechanisms are sufficiently well described and understood, the hope is that 'alloy design' simulations can assist tailoring of materials with desired properties. In pure Al-Mg-Si we have determined the structure of nearly all the known metastable precipitate phases, by combining advanced TEM techniques (such as high resolution TEM and nano-beam diffraction) with atom probe tomography and density functional theory. We are now studying effects of additions /substitutions of Cu, Ag and/or Ge that promote formation of more disordered precipitates, employing aberration corrected high angle annular dark field scanning TEM. We find that all metastable precipitates contain variations of a widely spaced 'Si/Ge network'. In spite of disorder or defects, this network is surprisingly well ordered, with hexagonal projected sub-cell dimensions a = b ? 0.4 nm and c (along the fully coherent precipitate main growth direction) equal to 0.405 nm or a multiple of it.

  16. Optimization of phosphate removal in anodizing aluminium wastewater.

    PubMed

    Chimenos, J M; Fernández, A I; Hernández, A; Haurie, L; Espiell, F; Ayora, C

    2006-01-01

    The wastewater produced after brightening and anodizing aluminium has high concentrations of phosphates and sulphates. The addition of MgO in a first physico-chemical wastewater treatment step makes the selective recovery of phosphates in the form of magnesium phosphates feasible, which may be reused as fertilizer. The proposed wastewater treatment process allows manufacturers to reduce more than 70% of the volume of the precipitate in the sedimentation reactor and more than 50% of the weight of the final disposal sludge. In this study, the use of an alternative low-grade MgO (LG-MgO) as a source of magnesium, which is cheaper than pure MgO, is investigated. The phosphate concentration and pH of the treated wastewater is controlled by the formation and precipitation of newberyite or bobierrite as a function of the magnesium source added. According to experimental data, a reaction mechanism is proposed. Although LG-MgO reacts more slowly than pure MgO and it is necessary to add 3-4 times the stoichiometric amount, this procedure has considerable economic and technical advantages. PMID:16343583

  17. Volatilisation and oxidation of aluminium scraps fed into incineration furnaces.

    PubMed

    Biganzoli, Laura; Gorla, Leopoldo; Nessi, Simone; Grosso, Mario

    2012-12-01

    Ferrous and non-ferrous metal scraps are increasingly recovered from municipal solid waste incineration bottom ash and used in the production of secondary steel and aluminium. However, during the incineration process, metal scraps contained in the waste undergo volatilisation and oxidation processes, which determine a loss of their recoverable mass. The present paper evaluates the behaviour of different types of aluminium packaging materials in a full-scale waste to energy plant during standard operation. Their partitioning and oxidation level in the residues of the incineration process are evaluated, together with the amount of potentially recoverable aluminium. About 80% of post-consumer cans, 51% of trays and 27% of foils can be recovered through an advanced treatment of bottom ash combined with a melting process in the saline furnace for the production of secondary aluminium. The residual amount of aluminium concentrates in the fly ash or in the fine fraction of the bottom ash and its recovery is virtually impossible using the current eddy current separation technology. The average oxidation levels of the aluminium in the residues of the incineration process is equal to 9.2% for cans, 17.4% for trays and 58.8% for foils. The differences between the tested packaging materials are related to their thickness, mechanical strength and to the alloy. PMID:22749723

  18. Role of magnesium in alleviation of aluminium toxicity in plants.

    PubMed

    Bose, Jayakumar; Babourina, Olga; Rengel, Zed

    2011-04-01

    Magnesium is pivotal for activating a large number of enzymes; hence, magnesium plays an important role in numerous physiological and biochemical processes affecting plant growth and development. Magnesium can also ameliorate aluminium phytotoxicity, but literature reports on the dynamics of magnesium homeostasis upon exposure to aluminium are rare. Herein existing knowledge on the magnesium transport mechanisms and homeostasis maintenance in plant cells is critically reviewed. Even though overexpression of magnesium transporters can alleviate aluminium toxicity in plants, the mechanisms governing such alleviation remain obscure. Possible magnesium-dependent mechanisms include (i) better carbon partitioning from shoots to roots; (ii) increased synthesis and exudation of organic acid anions; (iii) enhanced acid phosphatase activity; (iv) maintenance of proton-ATPase activity and cytoplasmic pH regulation; (v) protection against an aluminium-induced cytosolic calcium increase; and (vi) protection against reactive oxygen species. Future research should concentrate on assessing aluminium toxicity and tolerance in plants with overexpressed or antisense magnesium transporters to increase understanding of the aluminium-magnesium interaction. PMID:21273333

  19. Evaluation of certain food additives.

    PubMed

    2015-01-01

    This report represents the conclusions of a Joint FAO/WHO Expert Committee convened to evaluate the safety of various food additives, including flavouring agents, and to prepare specifications for identity and purity. The first part of the report contains a general discussion of the principles governing the toxicological evaluation of and assessment of dietary exposure to food additives, including flavouring agents. A summary follows of the Committee's evaluations of technical, toxicological and dietary exposure data for eight food additives (Benzoe tonkinensis; carrageenan; citric and fatty acid esters of glycerol; gardenia yellow; lutein esters from Tagetes erecta; octenyl succinic acid-modified gum arabic; octenyl succinic acid-modified starch; paprika extract; and pectin) and eight groups of flavouring agents (aliphatic and alicyclic hydrocarbons; aliphatic and aromatic ethers; ionones and structurally related substances; miscellaneous nitrogen-containing substances; monocyclic and bicyclic secondary alcohols, ketones and related esters; phenol and phenol derivatives; phenyl-substituted aliphatic alcohols and related aldehydes and esters; and sulfur-containing heterocyclic compounds). Specifications for the following food additives were revised: citric acid; gellan gum; polyoxyethylene (20) sorbitan monostearate; potassium aluminium silicate; and Quillaia extract (Type 2). Annexed to the report are tables summarizing the Committee's recommendations for dietary exposures to and toxicological evaluations of all of the food additives and flavouring agents considered at this meeting. PMID:26118220

  20. Modulation of the human immune response by the non-toxic and non-pyrogenic adjuvant aluminium hydroxide: effect on antigen uptake and antigen presentation.

    PubMed Central

    Mannhalter, J W; Neychev, H O; Zlabinger, G J; Ahmad, R; Eibl, M M

    1985-01-01

    The regulatory effects of an adjuvant (aluminium hydroxide) on the early phase of the immune response have been investigated. Adsorbing a soluble antigen (tetanus toxoid) to aluminium hydroxide led to a significant increase (P less than 0.001) in antigen-induced T-cell proliferation (macrophage-T-cell interaction, MTI) making aluminium hydroxide-adsorbed antigens especially suitable to study immunoregulatory changes in the early phase of the immune response. First studies revealed that this increase was due to an enhancement of antigen uptake by the antigen-presenting cell. However, under conditions allowing for the uptake of comparable amounts of soluble (TTs) or aluminium hydroxide-absorbed (TTAL) antigen, T-cell proliferation in response to TTAL was still higher than in response to TTS. This difference was especially pronounced if suboptimal antigen concentrations were used and could be explained by differences in the TTS-versus TTAL-induced release of interleukin-1 (IL-1). Pulsing with TTAL led to a substantial increase in IL-1 release by monocytes (MO) which then subsequently augmented antigen-induced T-cell proliferation. This was further supported by addition of exogenous IL-1 to cultures of T cells and TTS-pulsed MOs, which also significantly increased the T cells' proliferative response. These findings demonstrate that in the early phase of the immune response, aluminium hydroxide exerts its regulatory effect at the level of the antigen-presenting and mediator-releasing accessory cell. PMID:3876178

  1. Accumulation and toxicity of aluminium-contaminated food in the freshwater crayfish, Pacifastacus leniusculus.

    PubMed

    Woodburn, Katie; Walton, Rachel; McCrohan, Catherine; White, Keith

    2011-10-01

    The accumulation and toxicity of aluminium in freshwater organisms have primarily been examined following aqueous exposure. This study investigated the uptake, excretion and toxicity of aluminium when presented as aluminium-contaminated food. Adult Pacifastacus leniusculus were fed control (3 ?g aluminium/g) or aluminium-spiked pellets (420 ?g aluminium/g) over 28 days. Half the crayfish in each group were then killed and the remainder fed control pellets for a further 10 days (clearance period). Concentrations of aluminium plus the essential metals calcium, copper, potassium and sodium were measured in the gill, hepatopancreas, flexor muscle, antennal gland (kidney) and haemolymph. Histopathological analysis of tissue damage and sub-cellular distribution of aluminium were examined in the hepatopancreas. Haemocyte number and protein concentration in the haemolymph were analysed as indicators of toxicity. The hepatopancreas of aluminium-fed crayfish contained significantly more aluminium than controls on days 28 and 38, and this amount was positively correlated with the amount ingested. More than 50% of the aluminium in the hepatopancreas of aluminium-fed crayfish was located in sub-cellular fractions thought to be involved in metal detoxification. Aluminium concentrations were also high in the antennal glands of aluminium-fed crayfish suggesting that some of the aluminium lost from the hepatopancreas is excreted. Aluminium exposure via contaminated food caused inflammation in the hepatopancreas but did not affect the number of circulating haemocytes, haemolymph ion concentrations or protein levels. In conclusion, crayfish accumulate, store and excrete aluminium from contaminated food with only localised toxicity. PMID:21924698

  2. Corrosion of aluminium in soft drinks.

    PubMed

    Seruga, M; Hasenay, D

    1996-04-01

    The corrosion of aluminium (Al) in several brands of soft drinks (cola- and citrate-based drinks) has been studied, using an electrochemical method, namely potentiodynamic polarization. The results show that the corrosion of Al in soft drinks is a very slow, time-dependent and complex process, strongly influenced by the passivation, complexation and adsorption processes. The corrosion of Al in these drinks occurs principally due to the presence of acids: citric acid in citrate-based drinks and orthophosphoric acid in cola-based drinks. The corrosion rate of Al rose with an increase in the acidity of soft drinks, i.e. with increase of the content of total acids. The corrosion rates are much higher in the cola-based drinks than those in citrate-based drinks, due to the facts that: (1) orthophosphoric acid is more corrosive to Al than is citric acid, (2) a quite different passive oxide layer (with different properties) is formed on Al, depending on whether the drink is cola or citrate based. The method of potentiodynamic polarization was shown as being very suitable for the study of corrosion of Al in soft drinks, especially if it is combined with some non-electrochemical method, e.g. graphite furnace atomic absorption spectrometry (GFAAS). PMID:8638433

  3. Asthma due to aluminium soldering flux

    PubMed Central

    Sterling, G. M.

    1967-01-01

    Two patients have been studied who complained of dyspnoea after the inhalation of fumes from a new soldering flux recently developed for use in jointing aluminium which has been replacing copper as a material for electric cables. A previous survey of respiratory complaints after the use of this particular flux had failed to show any objective change in lung function, and the present cases are the first to be reported. Both subjects have been investigated by means of serial spirometry, peak flow rates, and body plethysmography following inhalation of small amounts of flux fumes; delayed and prolonged bronchoconstriction has been demonstrated. Similar results have been obtained after the inhalation of one of the main constituents of the flux, namely amino-ethyl ethanolamine, which is presumably the active allergic agent. The bronchial response is unusual in being delayed in onset but otherwise resembles pollen-sensitivity asthma rather than the infiltrative process seen in farmer's lung. The type of immune mechanism involved is speculative, but it is possible that some alteration of the amino-ethyl ethanolamine is needed before it can react with reaginic antibody fixed in the bronchial tissues. PMID:6076508

  4. Potlining Additives

    SciTech Connect

    Rudolf Keller

    2004-08-10

    In this project, a concept to improve the performance of aluminum production cells by introducing potlining additives was examined and tested. Boron oxide was added to cathode blocks, and titanium was dissolved in the metal pool; this resulted in the formation of titanium diboride and caused the molten aluminum to wet the carbonaceous cathode surface. Such wetting reportedly leads to operational improvements and extended cell life. In addition, boron oxide suppresses cyanide formation. This final report presents and discusses the results of this project. Substantial economic benefits for the practical implementation of the technology are projected, especially for modern cells with graphitized blocks. For example, with an energy savings of about 5% and an increase in pot life from 1500 to 2500 days, a cost savings of $ 0.023 per pound of aluminum produced is projected for a 200 kA pot.

  5. Absolutely Addition

    NSDL National Science Digital Library

    Mrs. Korth

    2005-03-23

    Here are some fun games and activities to help with understanding and using addition. NUMBER LINE PRACTICE Begin with this fun game Line Jumper. Click on the medium level and complete all ten number line problems. When finished close the window and return to complete the next assignment. MR. BEAR\\'S CLOSET In this exciting activiy, Mr. Bear can\\'t decide what to wear. Can you help him? ...

  6. Influence of nanoporous structure on mechanical strength of aluminium and aluminium alloy adhesive structural joints

    NASA Astrophysics Data System (ADS)

    Spadaro, C.; Dispenza, C.; Sunseri, C.

    2006-08-01

    The influence of surface treatments on the mechanical strength of adhesive joints was investigated. The attention was focused on AA2024 alloy because it is extensively used in both the automotive and aerospace industries. Adhesive joints fabricated with pure aluminium were also investigated in order to evidence possible differences in the surface features after identical treatments. Before joining with a commercial epoxy adhesive, metal substrates were subjected to different kinds of treatment and the surfaces were characterized by SEM analysis. The formation of a microporous surface in the AA2024 alloy, upon etching and anodizing, is discussed on the basis of the role of the intermetallic particles and their electrochemical behaviour with respect to the aluminium matrix. Moreover, nanostructured porous oxide layers on both type of substrate were also formed, as a consequence of the anodizing process. Differences in their morphologies were revealed as a function of both the applied voltage and the presence of alloying elements. On this basis, an explanation of the different values of fracture energy measured by means of T-peel tests carried out on the corresponding joints was attempted.

  7. Electron density determination of aluminium laser-induced plasma

    NASA Astrophysics Data System (ADS)

    Surmick, D. M.; Parigger, C. G.

    2015-06-01

    We present temporally and spatially resolved electron density results of laser-induced plasma initiated on the surface of an aluminium target. Aluminium 394.4 and 396.15 nm lines were fit to Lorentzian profiles to evaluate Stark widths and shifts. Experimentally determined electron density versus line width and shift relationships were applied. Fitting to the aluminium lines indicates an electron density of 1.9 ± 0.2 and 3.2+/- 0.4× {{10}18} c{{m}-3} for Stark widths and 1.7 ± 0.5 and 1.7+/- 0.5× {{10}18} c{{m}-3} for Stark shifts at a 0.3 ?s time delay following plasma initiation for the aluminium Al i 394.4 and 396.15 nm transitions, respectively. Simultaneous observations of the singly ionized nitrogen line, N ii, at 395.5 nm were also fit for a time delay of 0.2 ?s, indicating an electron density of 1.8+/- 1.0× {{10}18} c{{m}-3}. The differences between the nitrogen and aluminium electron densities show evidence of self absorption.

  8. Computer modelling of age hardening for cast aluminium alloys

    NASA Astrophysics Data System (ADS)

    Wu, Linda; Ferguson, W. George

    2009-08-01

    Age hardening, or precipitation hardening, is one of the most widely adopted techniques for strengthening of aluminium alloys. Although various age hardening models have been developed for aluminium alloys, from the large volume of literature reviewed, it appears that the bulk of the research has been concentrated on wrought aluminium alloys, only a few of the established precipitation models have been applied to the casting aluminium alloys. In the present work, there are two modelling methods that have been developed and applied to the casting aluminium alloys A356 and A357. One is based on the Shercliff-Ashby methodology to produce a process model, by which we mean a mathematical relationship between process variables (alloy composition, ageing temperature and time) and material properties (yield strength or hardness) through microstructure evolution (precipitate radius, volume fraction). The other method is based on the Kampmann and Wagner Numerical (KWN) model which deals with concomitant nucleation, growth and coarsening and is thus capable of predicting the full evolution of the particle size distribution and then a strength model is used to evaluate the resulting change in hardness or yield strength at room temperature by taking into account contributions from lattice resistance, solid solution hardening and precipitation hardening.

  9. Effects on the nervous system in different groups of workers exposed to aluminium

    PubMed Central

    Iregren, A; Sjogren, B; Gustafsson, K; Hagman, M; Nylen, L; Frech, W; Andersson, M; Ljunggren, K; Wennberg, A

    2001-01-01

    OBJECTIVE—To investigate possible neurotoxic effects in groups of aluminium pot room and foundry workers, aluminium welders, and a small group of workers exposed to aluminium in the production of flake powder.?METHODS—Exposure to aluminium was evaluated with aluminium concentrations in blood and urine as well as a questionnaire. The groups exposed to aluminium were compared with a group of mild steel welders. Neurotoxic effects were studied with mood and symptom questionnaires and several psychological and neurophysiological tests.?RESULTS—The pot room and foundry workers showed very low aluminium uptake as their aluminium concentrations in blood and urine were close to normal, and no effects on the nervous system were detected. The group of workers exposed to flake powder had high concentrations of aluminium in blood and urine, even higher than those of the aluminium welders. However, aluminium could not be shown to affect the functioning of the nervous system in flake powder producers. Although significant effects could not be shown in the present analysis of the data on welders, the performance of the welders exposed to high concentrations of aluminium was affected according to the analyses in the original paper from this group.?CONCLUSIONS—For the pot room and foundry workers no effects related to the exposure to aluminium could be found. For the group of flake powder producers exposed for a short term no effects on the nervous systems were evident despite high levels of exposure. Due to the high concentrations of aluminium in the biological samples of this group, measures to reduce the exposure to aluminium are recommended, as effects on the central nervous system might develop after protracted exposures. However, this assumption needs to be verified in further studies.???Keywords: aluminium; workers; nervous system PMID:11404450

  10. Characterisation of the anodic layers formed on 2024 aluminium alloy, in tetraborate electrolyte containing molybdate ions

    NASA Astrophysics Data System (ADS)

    Moutarlier, V.; Pelletier, S.; Lallemand, F.; Gigandet, M. P.; Mekhalif, Z.

    2005-12-01

    Anodic layer growth on 2024 aluminium alloy at 70 °C, under 40 V, during 60 min, in 50 g L -1 di-sodium tetraborate solution containing di-sodium molybdate from 0.1 to 0.5 M (pH 10) is examined. Anodising behaviours strongly depend on additive concentration. Development of anodic films is favoured with weak molybdate additions (<0.3-0.4 M). The film thicknesses increase and the porosity of anodic layers decreases. Molybdenum (+VI), detected by X-ray photoelectron spectroscopy (XPS) analysis, is present in the anodic films and the Mo incorporation, studied by energy dispersive spectroscopy (EDS) analysis, increases with molybdate concentration. However, for high molybdate concentrations (>0.4 M), anodising behaviour becomes complex with the formation of a blue molybdenum oxide at the cathode. The growth of aluminium oxide is hindered. As the anodic layers are thinner, the Mo(+VI) incorporation significantly decreases. These two configurations implicate different corrosion performances in 5% sodium chloride solution at 35 °C. As the alkaline anodic layer formed with 0.3 M molybdate species is the thickest and the Mo incorporation is the more pronounced, its corrosion resistance is the highest. The effect of morphology and composition of anodic films on pitting corrosion is also discussed.

  11. Stimulation of eryptosis by aluminium ions

    SciTech Connect

    Niemoeller, Olivier M. [Department of Physiology, University of Tuebingen (Germany); Kiedaisch, Valentin [Department of Physiology, University of Tuebingen (Germany); Dreischer, Peter [Department of Physiology, University of Tuebingen (Germany); Wieder, Thomas [Department of Physiology, University of Tuebingen (Germany); Lang, Florian [Department of Physiology, University of Tuebingen (Germany)]. E-mail: florian.lang@uni-tuebingen.de

    2006-12-01

    Aluminium salts are utilized to impede intestinal phosphate absorption in chronic renal failure. Toxic side effects include anemia, which could result from impaired formation or accelerated clearance of circulating erythrocytes. Erythrocytes may be cleared secondary to suicidal erythrocyte death or eryptosis, which is characterized by cell shrinkage and exposure of phosphatidylserine (PS) at the erythrocyte surface. As macrophages are equipped with PS receptors, they bind, engulf and degrade PS-exposing cells. The present experiments have been performed to explore whether Al{sup 3+} ions trigger eryptosis. The PS exposure was estimated from annexin binding and cell volume from forward scatter in FACS analysis. Exposure to Al{sup 3+} ions ({>=} 10 {mu}M Al{sup 3+} for 24 h) indeed significantly increased annexin binding, an effect paralleled by decrease of forward scatter at higher concentrations ({>=} 30 {mu}M Al{sup 3+}). According to Fluo3 fluorescence Al{sup 3+} ions ({>=} 30 {mu}M for 3 h) increased cytosolic Ca{sup 2+} activity. Al{sup 3+} ions ({>=} 10 {mu}M for 24 h) further decreased cytosolic ATP concentrations. Energy depletion by removal of glucose similarly triggered annexin binding, an effect not further enhanced by Al{sup 3+} ions. The eryptosis was paralleled by release of hemoglobin, pointing to loss of cell membrane integrity. In conclusion, Al{sup 3+} ions decrease cytosolic ATP leading to activation of Ca{sup 2+}-permeable cation channels, Ca{sup 2+} entry, stimulation of cell membrane scrambling and cell shrinkage. Moreover, Al{sup 3+} ions lead to loss of cellular hemoglobin, a feature of hemolysis. Both effects are expected to decrease the life span of circulating erythrocytes and presumably contribute to the development of anemia during Al{sup 3+} intoxication.

  12. PROPRITS MAGNTIQUES DU GRENAT D'ALUMINIUM ET DE DYSPROSIUM I. THORIE A 0 K

    E-print Network

    Paris-Sud XI, Université de

    57. PROPRIÉTÉS MAGNÉTIQUES DU GRENAT D'ALUMINIUM ET DE DYSPROSIUM I. THÉORIE A 0 °K Par R. BIDAUX'aluminium et de dysprosium l'application d'un champ magnétique assez intense est susceptible de découpler les'aluminium et de dysprosium (DAG) d'un champ magnétique appliqué parallèlement à un axe ternaire ou quaternaire

  13. Different Approach to the Aluminium Oxide Topography Characterisation

    SciTech Connect

    Poljacek, Sanja Mahovic; Gojo, Miroslav [Faculty of Graphic Arts, University of Zagreb, Getaldiceva 2, 10000 Zagreb (Croatia); Raos, Pero; Stoic, Antun [Mechanical Engineering Faculty, J.J. Strossmayer University of Osijek, Trg Ivane Brlic Mazuranic 2, 35000 Slavonski Brod (Croatia)

    2007-04-07

    Different surface topographic techniques are being widely used for quantitative measurements of typical industrial aluminium oxide surfaces. In this research, specific surface of aluminium oxide layer on the offset printing plate has been investigated by using measuring methods which have previously not been used for characterisation of such surfaces. By using two contact instruments and non-contact laser profilometer (LPM) 2D and 3D roughness parameters have been defined. SEM micrographs of the samples were made. Results have shown that aluminium oxide surfaces with the same average roughness value (Ra) and mean roughness depth (Rz) typically used in the printing plate surface characterisation, have dramatically different surface topographies. According to the type of instrument specific roughness parameters should be used for defining the printing plate surfaces. New surface roughness parameters were defined in order to insure detailed characterisation of the printing plates in graphic reproduction process.

  14. Modelling of micro- and macrosegregation for industrial multicomponent aluminium alloys

    NASA Astrophysics Data System (ADS)

    Ellingsen, K.; Mortensen, D.; M'Hamdi, M.

    2015-06-01

    Realistic predictions of macrosegregation formation during casting of aluminium alloys requires an accurate modeling of solute microsegregation accounting for multicomponent phase diagrams and secondary phase formation. In the present work, the stand alone Alstruc model, a microsegregation model for industrial multicomponent aluminium alloys, is coupled with the continuum model ALSIM which calculates the macroscopic transport of mass, enthalpy, momentum, and solutes as well as stresses and deformation during solidification of aluminium. Alstruc deals with multicomponent alloys accounting for temperature dependent partition coefficients, liquidus slopes and the precipitation of secondary phases. The challenge associated with computation of microsegregation for multicomponent alloys is solved in Alstruc by approximating the phase diagram data by simple, analytical expressions which allows for a CPU-time efficient coupling with the macroscopic transport model. In the present work, the coupled model has been applied in a study of macrosegregation including thermal and solutal convection, solidification shrinkage and surface exudation on an industrial DC-cast billet.

  15. Reflection of infrared radiation from thin aluminium layers

    E-print Network

    Calatroni, Sergio

    2001-01-01

    The thermal shielding of the LHC magnets cryostats will make use of Multi-Layer Insulation. This is a sandwich of several Mylar (polyester) foils 6 µm thick coated with a thin film of aluminium, having a thickness of some 30 nm. The thickness of the aluminium film must be kept at a minimum to minimise lateral thermal conduction. The outer layer of this sandwich stays at a temperature of 20 K or below, and receives IR radiation from surfaces at 77 K (wavelength of 37.6 µm at the peak of blackbody radiation), which should be reflected with the highest efficiency. The minimum thickness for the aluminium layer to avoid transmission of the radiation can be calculated by making use of the skin effect theory, taking into account the changes in electrical properties that are due to the extremely low thickness of the film.

  16. Crushing modes of aluminium tubes under axial compression

    E-print Network

    Florent Henri Marc Rémy Pled; Wenyi Yan; Cui'E Wen

    2014-08-21

    A numerical study of the crushing of circular aluminium tubes with and without aluminium foam fillers has been carried out to investigate their buckling behaviours under axial compression. A crushing mode classification chart has been established for empty tubes. The influence of boundary conditions on crushing mode has also been investigated. The effect of foam filler on the crushing mode of tubes filled with foam was then examined. The predicted results would assist the design of crashworthy tube components with the preferred crushing mode with the maximum energy absorption.

  17. Effects of surface treatment of aluminium alloy 1050 on the adhesion and anticorrosion properties of the epoxy coating

    NASA Astrophysics Data System (ADS)

    Sharifi Golru, S.; Attar, M. M.; Ramezanzadeh, B.

    2015-08-01

    The objective of this work is to investigate the effects of zirconium-based (Zr) conversion coating on the adhesion properties and corrosion resistance of an epoxy/polyamide coating applied on the aluminium alloy 1050 (AA1050). Field emission scanning electron microscope (FE-SEM), energy dispersive X-ray spectrum (EDS), atomic force microscope (AFM) and contact angle measuring device were employed in order to characterize the surface characteristics of the Zr treated AA1050 samples. The epoxy/polyamide coating was applied on the untreated and Zr treated samples. The epoxy coating adhesion to the aluminium substrate was evaluated by pull-off test before and after 30 days immersion in 3.5% w/w NaCl solution. In addition, the electrochemical impedance spectroscopy (EIS) and salt spray tests were employed to characterize the corrosion protection properties of the epoxy coating applied on the AA1050 samples. Results revealed that the surface treatment of AA1050 by zirconium conversion coating resulted in the increase of surface free energy and surface roughness. The dry and recovery (adhesion strength after 30 days immersion in the 3.5 wt% NaCl solution) adhesion strengths of the coatings applied on the Zr treated aluminium samples were greater than untreated sample. In addition, the adhesion loss of the coating applied on the Zr treated aluminium substrate was lower than other samples. Also, the results obtained from EIS and salt spray test clearly revealed that the Zr conversion coating could enhance the corrosion protective performance of the epoxy coating significantly.

  18. Accumulation of Aluminium and Physiological Status of Tree Foliage in the Vicinity of a Large Aluminium Smelter

    PubMed Central

    Wannaz, E. D.; Rodriguez, J. H.; Wolfsberger, T.; Carreras, H. A.; Pignata, M. L.; Fangmeier, A.; Franzaring, J.

    2012-01-01

    A pollution gradient was observed in tree foliage sampled in the vicinity of a large aluminium production facility in Patagonia (Argentina). Leaves of Eucalyptus rostrata, and Populus hybridus and different needle ages of Pinus spec. were collected and concentrations of aluminium (Al) and sulphur (S) as well as physiological parameters (chlorophyll and lipid oxidation products) were analyzed. Al and S concentrations indicate a steep pollution gradient in the study showing a relationship with the physiological parameters in particular membrane lipid oxidation products. The present study confirms that aluminium smelting results in high Al and sulphur deposition in the study area, and therefore further studies should be carried out taking into account potentially adverse effects of these compounds on human and ecosystem health. PMID:22654642

  19. ALUMINIUM ACCUMULATION IN RUBIACEAE: AN ADDITIONAL CHARACTER FOR THE DELIMITATION OF THE SUBFAMILY RUBIOIDEAE?

    Microsoft Academic Search

    S. Jansen; E. Robbrecht; H. Beeckman; E. Smets

    2000-01-01

    SUMMARY The chrome azurol-S test, which is a chemical spot-test for Al accumu- lation in wood, was applied to 443 wood samples of members of the Rubiaceae. A positive reaction was found in 103 specimens. Compari- son of the results with earlier analyses of leaves of Rubiaceae shows that Al accumulation occurs more frequently in leaves than in wood. The

  20. Plasma and urine aluminium concentrations in healthy subjects after administration of sucralfate.

    PubMed Central

    Allain, P; Mauras, Y; Krari, N; Duchier, J; Cournot, A; Larcheveque, J

    1990-01-01

    1. Sucralfate (basic sucrose aluminium sulphate), a topical intestinal agent, was administered in suspension or granule form to 25 healthy subjects at a total dose of 4 g day-1 for 21 days. Aluminium in plasma and 24 h urine samples was assayed before, during and after administration of sucralfate by inductively coupled plasma optical emission spectrometry. 2. Sucralfate produced significant increases in plasma and urine aluminium concentrations. On average, plasma aluminium increased from about 2 micrograms 1-1 to more than 5 micrograms 1-1 and 24 h urine aluminium increased from less than 5 micrograms to more than 30 micrograms. Both plasma and urine aluminium concentrations decreased rapidly after sucralfate was stopped. However, urinary aluminium concentrations remained higher than normal 5 and 10 days after discontinuation of sucralfate administration. Moreover subjects receiving sucralfate granules had significantly higher average urinary excretion of aluminium than subjects receiving the suspension. 3. The small but significant increase in plasma and urine aluminium following sucralfate administration in therapeutic doses may reflect intestinal absorption of aluminium. Although such absorption would appear to be moderate in healthy subjects, it is suggested that aluminium-based treatments should be used only intermittently, especially in patients with renal disorders. PMID:2328192

  1. Synthesis of Cyclic Carbonates Catalysed by Aluminium Heteroscorpionate Complexes.

    PubMed

    Martínez, Javier; Castro-Osma, José A; Earlam, Amy; Alonso-Moreno, Carlos; Otero, Antonio; Lara-Sánchez, Agustín; North, Michael; Rodríguez-Diéguez, Antonio

    2015-06-26

    New aluminium scorpionate based complexes have been prepared and used for the synthesis of cyclic carbonates from epoxides and carbon dioxide. Bimetallic aluminium(heteroscorpionate) complexes 9-14 were synthesised in very high yields. The single-crystal X-ray structures of 12 and 13 confirm an asymmetric ?(2) -NO-?-O arrangement in a dinuclear molecular disposition. These bimetallic aluminium complexes were investigated as catalysts for the synthesis of cyclic carbonates from epoxides and carbon dioxide in the presence of ammonium salts. Under the optimal reaction conditions, complex 9 in combination with tetrabutylammonium bromide acts as a very efficient catalyst system for the conversion of both monosubstituted and internal epoxides into the corresponding cyclic carbonates showing broad substrate scope. Complex 9 and tetrabutylammonium bromide is the second most efficient aluminium-based catalyst system for the reaction of internal epoxides with carbon dioxide. A kinetic study has been carried out and showed that the reactions were first order in complex 9 and tetrabutylammonium bromide concentrations. Based on the kinetic study, a catalytic cycle is proposed. PMID:26032761

  2. Recent development in aluminium alloys for the automotive industry

    Microsoft Academic Search

    W. S. Miller; L. Zhuang; J. Bottema; A. J. Wittebrood; P De Smet; A. Haszler; A. Vieregge

    2000-01-01

    The growing demand for more fuel-efficient vehicles to reduce energy consumption and air pollution is a challenge for the automotive industry. The characteristic properties of aluminium, high strength stiffness to weight ratio, good formability, good corrosion resistance, and recycling potential make it the ideal candidate to replace heavier materials (steel or copper) in the car to respond to the weight

  3. COMPARISON OF MHD MODELS FOR ALUMINIUM REDUCTION CELLS

    Microsoft Academic Search

    V. Bojarevics; K. Pericleous

    The self sustained waves at the aluminium-electrolyte interface, known as 'MHD noise', are observed in the most of commercial cells under certain conditions. The instructive analysis is presented how a step by step inclusion of different physical coupling factors is affecting the wave development in the electrolysis cells. The early theoretical models for wave development do not account for the

  4. Theoretical modelling of fatigue threshold for aluminium alloys

    Microsoft Academic Search

    Xu-Dong Li; L. Edwards

    1996-01-01

    The fatigue limit of aluminium alloys is logically modelled as edge dislocations against grain boundaries. A fictitious shear crack is envisioned to represent the fatigue limit condition. By using continuous configuration in the dislocation pile-up, the crack tip sliding displacement can be determined for the shear crack and the fatigue limit is attained when the shear crack is just onset

  5. Investigations on solution derived aluminium doped zinc oxide thin films

    Microsoft Academic Search

    S. B Majumder; M Jain; P. S Dobal; R. S Katiyar

    2003-01-01

    Aluminium (Al) doped transparent zinc oxide thin films have been successfully grown on sapphire (0001) substrates by an economical chemical solution deposition technique. These films were characterized in terms of their structural, optical, and electrical properties. Detailed XPS analysis of the O1s core level spectra has been carried out for the ZnO films annealed at different temperatures. Lower binding energy

  6. The behaviour of leached aluminium in tea infusions

    Microsoft Academic Search

    Chao Yan Zhou; Jun Wu; Hua Chi; Ming Keong Wong; Lip Lin Koh; Yeow Chin Wee

    1996-01-01

    The behavior of leached aluminium (Al) was studied using GF-AAS with different sample pretreatments and RP-HPLC with lumogallion as the precolumn reagent. The results showed that Al species in tea infusion could be categorized into three groups: large organic compounds, small stable organic compounds and free form Al. The compositions of Al species in a tea infusion would vary with

  7. THE MAGNETOCRYSTALLINE ANISOTROPY OF GALLIUM AND ALUMINIUM SUBSTITUTED MAGNETITE

    E-print Network

    Paris-Sud XI, Université de

    409 THE MAGNETOCRYSTALLINE ANISOTROPY OF GALLIUM AND ALUMINIUM SUBSTITUTED MAGNETITE By R. F of the magnetocrystalline anisotropy in magnetite (Fe3O4) as this shows a rather anomalous variation with temperature constante d'anisotropie K1 ont été mesurées de 120 °K à 400 °K par la méthode de torsion, pour sept cristaux

  8. Frottement intérieur de l'aluminium très faiblement écroui

    Microsoft Academic Search

    J. L. Chevalier; P. Peguin; J. Perez; P. Gobin

    1972-01-01

    The internal friction and the modulus anomaly of high-purity, slightly cold-worked aluminium have been measured against temperature. In particular, a complex peak with its maximum at 130 K was observed and studied. It has been found that this phenomenon could be due essentially to a mechanism of interaction between linear and point defects. The Bordoni peak could contribute to the

  9. A review on friction stir welding for aluminium alloys

    Microsoft Academic Search

    M. Sivashanmugam; S. Ravikumar; T. Kumar; V. S. Rao; D. Muruganandam

    2010-01-01

    Friction stir welding is a solid state welding process which involves joining similar or dissimilar metals using a rotating tool. Tool geometry and traverse speed and rotating speed of motion of the tool, tool axial force and tilt angle are some of the variables in this process. Many materials like Aluminium alloy 2000, 6000 and 7000 series have been joined

  10. INTERGRANULAR CORROSION OF SINGLE PHASE ALUMINIUM AS A PITTING PHENOMENON

    E-print Network

    Paris-Sud XI, Université de

    INTERGRANULAR CORROSION OF SINGLE PHASE ALUMINIUM AS A PITTING PHENOMENON M. METZGER Department of pitting corrosion in sulfuric acid containing sodium chloride were described. Intergranular fissuring in producing this type of attack. The intergranular corrosion phenomena which are exhibited by high purity

  11. High effective organic corrosion inhibitors for 2024 aluminium alloy

    Microsoft Academic Search

    S. V. Lamaka; M. L. Zheludkevich; K. A. Yasakau; M. F. Montemor; M. G. S. Ferreira

    2007-01-01

    The inhibiting effect of several organic compounds on the corrosion of 2024 aluminium alloy in neutral chloride solution was investigated in the present work. The candidates were selected based on the assumption that effective inhibitors should form highly insoluble complexes with components of AA2024. Along with organic complexing agents, the salts of rare-earth elements were included into screening electrochemical impedance

  12. Recovery of valuable materials from aluminium salt cakes

    Microsoft Academic Search

    W. J. Bruckard; J. T. Woodcock

    2009-01-01

    Salt cakes, which are nominally waste products derived from aluminium dross melting furnaces, are complex mixtures of some 20 different compounds made up of many different elements. Normally they are regarded as waste products and they are disposed of in toxic waste dumps. However, it is shown here that some components are readily recoverable as high-grade products for recycling or

  13. Crash and structural analyses of an aluminium railroad passenger car

    Microsoft Academic Search

    C. Baykasoglu; E. Sunbuloglu; S. E. Bozdag; F. Aruk; T. Toprak; A. Mugan

    2012-01-01

    Crashworthiness, strength and vibrational features of a railroad passenger car, which is originally made of steel members and then converted to an aluminium design, are studied. The finite element (FE) method is utilised for the static analysis in compliance with various scenarios defined in UIC CODE OR 577, modal analysis and simulation of the crash into a rigid wall. Firstly,

  14. [Evaluation of toxic dust factor in aluminium production (analytic review)].

    PubMed

    Shayakhmetov, S F; Lisetskaya, L G; Merinov, A V

    2015-01-01

    Ambient air of aluminium production appeared to contain over thirty pollutants. Identification and quantitative evaluation of these pollutants are very difficult. Nature of occurring mixtures and their physical and chemical aggregate state remain unclear. Topical problem is to expand a list of detectable components via contemporary chemical analytic studies. PMID:26065243

  15. Aluminium hydride: a reversible material for hydrogen storage.

    PubMed

    Zidan, Ragaiy; Garcia-Diaz, Brenda L; Fewox, Christopher S; Stowe, Ashley C; Gray, Joshua R; Harter, Andrew G

    2009-07-01

    Aluminium hydride has been synthesized electrochemically, providing a synthetic route which closes a reversible cycle for regeneration of the material and bypasses expensive thermodynamic costs which have precluded AlH(3) from being considered as a H(2) storage material. PMID:19557259

  16. Carbon capture and the aluminium industry: preliminary studies

    Microsoft Academic Search

    Graham B Jones; Gargi Joshi; Malcolm D Clark; David M McConchie

    2006-01-01

    Carbonation of raw red mud produced by aluminium refineries and a chemically and physically neutralized red mud (Bauxsol™) has been carried out to study the capacity of these wastes to capture carbon dioxide. After only 5 min of carbonation of raw red mud, total alkalinity dropped 85%. Hydroxide alkalinity was almost totally consumed, carbonate alkalinity dropped by 88%, and bicarbonate

  17. Rapid quenching studies of a commercial aluminium alloy 2014

    Microsoft Academic Search

    C. Suryanarayana; M. Hanumantha Rao

    1987-01-01

    Aluminium alloys can be strengthened by cold working, precipitation hardening and thermomechanical treatments leading to very high values of strength-toweight ratio. The advent of rapid solidification techniques in the 1960s has benefited the alloy development programmes further. It is now well established that rapid quenching of alloys, at cooling rates above 105 K sec ', leads to several metastable effects

  18. Microstructural Evolution and Age Hardening in Aluminium Alloys

    Microsoft Academic Search

    S. P. Ringer; K. Hono

    2000-01-01

    This paper examines the microstructural evolution in selected aluminium alloys based on commercial age hardenable 2000, 6000, and 7000 series alloys. Atom probe field-ion microscopy and transmission electron microscopy have been used to examine the effects of microalloying and the origins of hardening. The combined application of these techniques is particularly important in the study of nanoscale precipitation processes. It

  19. Hot and warm forming of 2618 aluminium alloy

    Microsoft Academic Search

    P Cavaliere

    2002-01-01

    The hot and warm formability of 2618 aluminium alloy, in the as-solutioned condition, was investigated in extended ranges of temperature and strain rate by means of torsion testing. Precipitation was found to occur during deformation. The effect of the precipitation of second phase particles, occurring during deformation, on the flow curve shape and on the stress level was evaluated. At

  20. A tapered aluminium microelectrode array for improvement of dielectrophoresis-based particle manipulation.

    PubMed

    Buyong, Muhamad Ramdzan; Larki, Farhad; Faiz, Mohd Syafiq; Hamzah, Azrul Azlan; Yunas, Jumrail; Majlis, Burhanuddin Yeop

    2015-01-01

    In this work, the dielectrophoretic force (F(DEP)) response of Aluminium Microelectrode Arrays with tapered profile is investigated through experimental measurements and numerical simulations. A standard CMOS processing technique with a step for the formation of a tapered profile resist is implemented in the fabrication of Tapered Aluminium Microelectrode Arrays (TAMA). The F(DEP) is investigated through analysis of the Clausius-Mossotti factor (CMF) and cross-over frequency (f(xo)). The performance of TAMA with various side wall angles is compared to that of microelectrodes with a straight cut sidewall profile over a wide range of frequencies through FEM numerical simulations. Additionally, electric field measurement (EFM) is performed through scanning probe microscopy (SPM) in order to obtain the region of force focus in both platforms. Results showed that the tapered profile microelectrodes with angles between 60° and 70° produce the highest electric field gradient on the particles. Also, the region of the strongest electric field in TAMA is located at the bottom and top edge of microelectrode while the strongest electric field in microelectrodes with straight cut profile is found at the top corner of the microelectrode. The latter property of microelectrodes improves the probability of capturing/repelling the particles at the microelectrode's side wall. PMID:25970255

  1. Potential aluminium(III)- and gallium(III)-selective optical sensors based on porphyrazines.

    PubMed

    Goslinski, Tomasz; Tykarska, Ewa; Kryjewski, Michal; Osmalek, Tomasz; Sobiak, Stanislaw; Gdaniec, Maria; Dutkiewicz, Zbigniew; Mielcarek, Jadwiga

    2011-01-01

    Porphyrazines possessing non-coordinating alkyl (propyl) and aralkyl (4-tert-butylphenyl) groups in the periphery were studied as optical sensors for a set of mono-, di- and trivalent cations. Investigated porphyrazines in the UV-Vis monitored titrations revealed significant responses towards aluminium and gallium cations, unlike other metal ions studied. Additionally, porphyrazine possessing 4-tert-butylphenyl peripheral substituents showed sensor property towards ruthenium cation and was chosen for further investigation. The presence of isosbestic points in absorption spectra for its titration with aluminium, gallium and ruthenium cations, accompanied by a linear Benesi-Hildebrand plot, proved complex formation. The continuous variation method was used to determine binding stoichiometry in 1:1 porphyrazine-metal ratio. X-Ray studies and density functional theory calculations were employed to investigate octa(4-tert-butylphenyl)porphyrazine structure. The results helped to explain the observed selectivity towards certain ions. Interaction between ion and porphyrazine meso nitrogen in a Lewis acid-Lewis base manner is proposed. PMID:21558658

  2. A Tapered Aluminium Microelectrode Array for Improvement of Dielectrophoresis-Based Particle Manipulation

    PubMed Central

    Buyong, Muhamad Ramdzan; Larki, Farhad; Faiz, Mohd Syafiq; Hamzah, Azrul Azlan; Yunas, Jumrail; Majlis, Burhanuddin Yeop

    2015-01-01

    In this work, the dielectrophoretic force (FDEP) response of Aluminium Microelectrode Arrays with tapered profile is investigated through experimental measurements and numerical simulations. A standard CMOS processing technique with a step for the formation of a tapered profile resist is implemented in the fabrication of Tapered Aluminium Microelectrode Arrays (TAMA). The FDEP is investigated through analysis of the Clausius-Mossotti factor (CMF) and cross-over frequency (fxo). The performance of TAMA with various side wall angles is compared to that of microelectrodes with a straight cut sidewall profile over a wide range of frequencies through FEM numerical simulations. Additionally, electric field measurement (EFM) is performed through scanning probe microscopy (SPM) in order to obtain the region of force focus in both platforms. Results showed that the tapered profile microelectrodes with angles between 60° and 70° produce the highest electric field gradient on the particles. Also, the region of the strongest electric field in TAMA is located at the bottom and top edge of microelectrode while the strongest electric field in microelectrodes with straight cut profile is found at the top corner of the microelectrode. The latter property of microelectrodes improves the probability of capturing/repelling the particles at the microelectrode’s side wall. PMID:25970255

  3. Absorption, deposition and distribution of dietary aluminium in immature rats: Effects of dietary vitamin D3 and food?borne chelating agent

    Microsoft Academic Search

    J. Anthony; S. Fadl; C. Mason; A. Davison; J. Berry

    1986-01-01

    We report the levels of aluminium, calcium and potassium in selected tissues of growing rats administered dietary or subcutaneous aluminium, and also the effect of dietary aluminium in combination with cholecalciferol, or with lactose plus a dietary chelating agent. Dietary aluminium decreased the growth rate of normal rats and increased the deposition of aluminium in the tissues. Animals given lactose

  4. Aluminium tolerance in rice is antagonistic with nitrate preference and synergistic with ammonium preference

    PubMed Central

    Zhao, Xue Qiang; Guo, Shi Wei; Shinmachi, Fumie; Sunairi, Michio; Noguchi, Akira; Hasegawa, Isao; Shen, Ren Fang

    2013-01-01

    Background and Aims Acidic soils are dominated chemically by more ammonium and more available, so more potentially toxic, aluminium compared with neutral to calcareous soils, which are characterized by more nitrate and less available, so less toxic, aluminium. However, it is not known whether aluminium tolerance and nitrogen source preference are linked in plants. Methods This question was investigated by comparing the responses of 30 rice (Oryza sativa) varieties (15 subsp. japonica cultivars and 15 subsp. indica cultivars) to aluminium, various ammonium/nitrate ratios and their combinations under acidic solution conditions. Key Results indica rice plants were generally found to be aluminium-sensitive and nitrate-preferring, while japonica cultivars were aluminium-tolerant and relatively ammonium-preferring. Aluminium tolerance of different rice varieties was significantly negatively correlated with their nitrate preference. Furthermore, aluminium enhanced ammonium-fed rice growth but inhibited nitrate-fed rice growth. Conclusions The results suggest that aluminium tolerance in rice is antagonistic with nitrate preference and synergistic with ammonium preference under acidic solution conditions. A schematic diagram summarizing the interactions of aluminium and nitrogen in soil–plant ecosystems is presented and provides a new basis for the integrated management of acidic soils. PMID:23118122

  5. Laser-induced electrochemical de- and repassivation investigations on plasma-oxidized aluminium alloys

    NASA Astrophysics Data System (ADS)

    Nagy, Tristan O.; Pacher, Ulrich; Giesriegl, Ariane; Soyka, Lukas; Trettenhahn, Günter; Kautek, Wolfgang

    2014-05-01

    In situ laser depassivation of plasma electrolytically oxididized (PEO) coatings on aluminium was investigated with nanosecond pulses. Ultraviolet radiation of 266 nm was chosen in order to achieve a high absorption in the dielectric coating. The additive accumulation of laser-induced material defects (incubation) affected the depassivation processes. Incubation occurred only at the edges of the ablation craters irradiated by the outer region of the Gaussian beam profile, where the local fluence is below the ablation threshold. The ablation rate in the spot center did not exhibit an incubation effect. Repassivation was interpreted by a linear combination of a high-field and a point defect growth model. At low overpotentials, field gradients affect the process driving the oxide growth at the buried interface. At high fields, corrosion reactions dominate at the oxide/solution interface.

  6. Histopathological changes in cases of aluminium phosphide poisoning.

    PubMed

    Sinha, U S; Kapoor, A K; Singh, A K; Gupta, A; Mehrotra, Ravi

    2005-04-01

    Of a total of 205 poisoning deaths in our hospital in 2003, 83 cases were due to Aluminium phosphide poisoning and were further analyzed. Most vulnerable age group was 21-40 years and M:F ratio was 2:1. On naked eye examination, almost all the vital organs were found to be congested. On microscopic study, the liver showed central venous congestion, degeneration, haemorrhage, sinusoidal dilation, bile stasis, centrilobular necrosis, Kupffer cell hyperplasia, infiltration by mononuclear cells and fatty change. Microscopy of the lungs revealed alveolar thickening, oedema, dilated capillaries, collapsed alveoli and haemorrhage. In the kidney, changes were degeneration, infiltration, tubular dilation and cloudy swelling. Changes in the brain included congestion and coagulative necrosis and in the stomach, congestion and haemorrhage. Easy availability of this cheap and highly toxic substance was responsible for the sudden spurt of poisoning with aluminium phosphide. PMID:16758658

  7. Results of the Experiment: Welding of Aluminium Alloy in Microgravity

    NASA Astrophysics Data System (ADS)

    Ferretti, S.; Amadori, K.; Boccalatte, A.; Alessandrini, M.; Freddi, A.; Persiani, F.; Poli, G.

    2002-01-01

    An experiment on "dendritic growth in aluminium alloy welding" was performed by the UNIBO team during the 3rd Student Parabolic Flight Campaign and the 30th Professional Parabolic Flight Campaign organised by ESA. Its purpose was to achieve a better understanding of crystal growth during tungsten inert gas (TIG) welding of an aluminium alloy to define the main parameters affecting the process under microgravity condition. The experiment had 4 phases : The paper discusses different aspects of the research, paying particularly attention not only to the influence of gravity, but also to other factors influencing welding microstructure, such as the Marangoni effect and the thermal transfer from the electrode to the material. The paper conclude the dissertation of the results offering new perspectives for welding studies and proposing a new approach to the scientific community to investigate this materials processes for manufacturing.

  8. Theoretical investigation of (111) stacking faults in aluminium

    Microsoft Academic Search

    Alan F. Wright; Murray S. Daw; C. Y. Fong

    1992-01-01

    We have investigated (111) stacking faults in aluminium using the Kohn-Sham formulation of density-functional theory (DFT) along with plane-wave expansions for the Kohn-Sham functions and pseudopotentials to describe the interactions between the Kohn-Sham functions and the ions. We find that the energies of the intrinsic, extrinsic and twin stacking faults are 161, 151 and 74 mJ m- respectively. These values

  9. The stress dependence of the subgrain size in aluminium

    Microsoft Academic Search

    Timothy J. Ginter; Farghalli A. Mohamed

    1982-01-01

    Etch-pit (EP) technique and transmission electron microscopy (TEM) have been used to investigate the subgrain size, d, as a function of applied shear stress, t, during high-temperature creep of aluminium. Examination of thin foils, prepared from deformed specimens, in the electron microscope shows the presence of very large equiaxed sub-grains that approximate those observed in etch-pit photographs. By measuring the

  10. Experimental study of the ternary magnesium–aluminium–strontium system

    Microsoft Academic Search

    M. A. Parvez; M. Medraj; E. Essadiqi; A. Muntasar; G. Dénès

    2005-01-01

    The phase diagram of the ternary magnesium–aluminium–strontium (Mg–Al–Sr) system has been investigated with 22 different alloys by DSC, XRD and metallography. Liquidus temperature and enthalpy were determined. Al4Sr and (Mg) were found to be the dominating phases in the investigated alloys. Four new phase fields have been identified; the new phases were tentatively designated as ?1, ?2, ?3 and ?4

  11. Optical properties of Dy3+ doped yttrium aluminium borate

    Microsoft Academic Search

    R. Martínez Vázquez; R. Osellame; M. Marangoni; R. Ramponi; E. Diéguez; M. Ferrari; M. Mattarelli

    2004-01-01

    A Dy3+ doped yttrium-aluminium borate (Dy:YAB) crystal has been optically characterized. The refractive indices at seven different wavelengths, ranging from the visible to the near infrared (IR), have been measured and the Sellmeier curves have been calculated. The polarized optical absorption spectra have been obtained at room temperature, and the Judd-Ofelt parameters have been calculated. The lifetime of the upper

  12. Deposition of aluminium oxide thin films by reactive magnetron sputtering

    Microsoft Academic Search

    K Koski; J Hölsä; P Juliet

    1999-01-01

    Aluminium oxide thin films were deposited by direct current (d.c.) reactive magnetron sputtering on glass-slide, silicon wafer, stainless-steel and polycarbonate substrates. The thicknesses of the films were between 200nm and 3.0?m. The deposition was controlled by the target voltage to obtain stoichiometric thin films with a high deposition rate. The deposition process was studied in terms of target power, I–U

  13. Formation of alkoxy-derived yttrium aluminium oxides

    Microsoft Academic Search

    O. Yamaguchi; K. Takeoka; K. Hirota; H. Takano; A. Hayashida

    1992-01-01

    Monoclinic Y4Al2O9 and hexagonal YAlO3 crystallize at low temperatures from amorphous materials prepared by the hydrolysis of yttrium and aluminium double alkoxides. Hexagonal YAlO3 transforms to the cubic phase with a garnet structure as an intermediate product at elevated temperatures. The formation process of YAlO3 is described. Solid solutions of hexagonal YAlO3 crystallize between 50 and 62.5 mol % Al2O3.

  14. Frottement intérieur de l'aluminium pur après fatigue

    Microsoft Academic Search

    J. L. Chevalier; P. Peguin

    1974-01-01

    The internal friction and the modulus anomaly of high-purity aluminium fatigued at 78 K have been measured against temperature. The Bordoni peak has been found to be modified, and the `Hasiguti' peak found to be very important. This last peak can re-appear, after anealing at 180 K, by means of a slight cold-working. This phenomenon could be due essentially to

  15. Synthesis and physicochemical properties of cobalt aluminium hydrotalcites

    Microsoft Academic Search

    S. Kannan; S. Velu; V. Ramkumar; C. S. Swamy

    1995-01-01

    Cobalt aluminium hydrotalcites with different compositions were prepared by a coprecipitation method under low supersaturation conditions. The compounds were characterized by X-ray diffraction (XRD), infrared absorption (IR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and BET surface area measurements. XRD and IR studies revealed that all the compounds are single-phase crystallized under a hydrotalcite-like network. Hydrothermal treatments given to the

  16. Anodic film formation on high strength aluminium alloy FVS0812

    Microsoft Academic Search

    J. SYKES; G. E Thompson; D Mayo; P Skeldon

    1997-01-01

    Barrier-type film growth on the high strength aluminium alloy FVS0812 has been studied by a combination of transmission electron\\u000a microscopy and Rutherford backscattering spectroscopy. The film is composed mainly of amorphous anodic alumina, but is contaminated\\u000a with iron species incorporated into the film from the alloy. The film may also be contaminated with silicon and vanadium species\\u000a at levels below

  17. Modelling of aluminium sheet material at elevated temperatures

    Microsoft Academic Search

    L. van Haaren; Boogaard van den A. H; J. Huetink

    2004-01-01

    The formability of Al–Mg sheet can be improved considerably, by increasing the temperature.\\u000aAt elevated temperatures, the mechanical response of the material becomes strain rate dependent. To accurately\\u000asimulate warm forming of aluminium sheet, a material model is required that incorporates the temperature\\u000aand strain-rate dependency. In this paper hardening is described succesfully with a physically based material\\u000amodel for

  18. The Work Functions of Copper, Silver and Aluminium

    Microsoft Academic Search

    E. W. J. Mitchell; J. W. Mitchell

    1951-01-01

    The work functions of surfaces of copper, silver and aluminium, produced by the deposition of thin films of the metal from the vapour on to previously well-aged tungsten surfaces, have been found to be 4\\\\cdot 61 ± 0\\\\cdot 04, 4\\\\cdot 35 ± 0\\\\cdot 05 and 4\\\\cdot 25 ± 0\\\\cdot 05 eV respectively. These values are based on measurements of the

  19. Design of a dome-shaped aluminium water battery

    Microsoft Academic Search

    P. K. Shen; A. C. C. Tseung; C. Kuo

    1994-01-01

    Aluminium\\/water batteries using hydrogen evolving cathodes are one of the candidate batteries for sub-sea application. However, it is impractical to use parallel plate construction because the significant increase in the anode-cathode gap during long term anodic discharge leads to unacceptable iR losses. A conceptual design, using a dome-shaped configuration, is presented and preliminary tests on a prototype show that such

  20. The operation of a aluminium-air reserve power systems

    Microsoft Academic Search

    S. M. Warner

    1991-01-01

    Alupower-Chloride have developed a practical aluminium-air reserve battery which will provide over 150 Wh\\/dm3 and 250 Wh\\/kg on discharge. The author describes both the principles and practicalities of operation of the reserve battery and techniques for incorporating them into power systems. The battery is intended to be used in conjunction with conventional, rechargeable, standby batteries and DC\\/DC power conversion equipment

  1. Physical and electrochemical characteristics of aluminium-substituted nickel hydroxide

    Microsoft Academic Search

    B. Liu; X. Y. Wang; H. T. Yuan; Y. S. Zhang; D. Y. Song; Z. X. Zhou

    1999-01-01

    Substitution of 20 aluminium for nickel in the lattice of nickel hydroxide, prepared by coprecipitation, leads to a hydrotalcite-like compound of formula Ni0.8Al0.2(OH)2(CO3)0.1.0.66H2O. It has been found that the compound has prolonged stability in 6m KOH solution and can be used as the positive electrode material in rechargeable alkaline batteries. The structure, morphology and composition of the compound have been

  2. Interfacing the aluminium-air battery with telecommunications equipment

    Microsoft Academic Search

    P. Hodgson; M. Heath

    1990-01-01

    The tests carried out by British Telecom (BT) on the aluminum-air battery with regard to using the battery in a standby power system are described. The background to BT's interest in the aluminium-air battery is outlined along with the design considerations of a prototype power system to be installed in the switching network. The need for an interfacing DC\\/DC converter

  3. Structure of Age-Hardened Aluminium-Copper Alloys

    Microsoft Academic Search

    André Guinier

    1938-01-01

    WE have made X-ray diagrams of aluminium-copper alloys (5 per cent Cu) age-hardened at various temperatures (25°-200° C.); the samples were composed of large crystals, and the radiation was made monochromatic by reflection by a crystal. In a previous paper1, we described a new phenomenon which appeared in these diagrams: streaks of various length issuing from the centre, which we

  4. Grain-boundary segregation in aluminium-doped silicon carbide

    Microsoft Academic Search

    Yo Tajima; W. D. Kingery

    1982-01-01

    Scanning transmission electron microscopy (STEM) was used to examine sintered and hot-pressed aluminium-doped silicon carbide. Grain-boundary segregation of Al was observed in both materials. Semi-quantitative analysis was carried out on the Al-saturated hot-pressed material. An estimated heat of segregation between 116 and 174 kJ mol-1 was calculated from the STEM data and equilibrium segregation theory. Strain energy as a driving

  5. Wear of aluminium-base materials processed by mechanical milling in air or ammonia

    Microsoft Academic Search

    Patricia Iglesias; Mar??a-Dolores Bermúdez; Francisco J. Carrión; Ginés Mart??nez-Nicolás; Enrique J. Herrera; José A. Rodriguez; Moisés Naranjo

    2003-01-01

    The tribological behaviour of mechanically alloyed (MA) aluminium-base materials has been studied as a function of processing methods. In particular, a new sintered MA aluminium material, milled under an ammonia atmosphere (MA Al-NH3) and consolidated by a single cycle of cold compaction and sintering, is compared with conventional MA aluminium (MA Al-air), milled in confined air and consolidated by a

  6. Immunisation with aluminium-containing vaccine of a child with itching nodule following previous vaccination

    Microsoft Academic Search

    Marianne Sjølin Frederiksen; Hanne Tofte

    2004-01-01

    Vaccination of children with aluminium sensitisation against diphtheria and tetanus presents a problem, since vaccine without aluminium against these potentially serious infectious diseases is no longer available.This case report presents a 7-month-old boy who, after his second immunisation with DTaP-IPV, developed an itching injection site nodule. Before being tested for aluminium sensitisation, he was vaccinated again with DTaP-IPV without developing

  7. Selected properties of the aluminium alloy base composites reinforced with intermetallic particles

    Microsoft Academic Search

    M. Adamiak

    2006-01-01

    Purpose: The main aim of this work is to investigate two types of intermetallics TiAl and Ti3Al as reinforcement and their influence on selected properties and microstructure of aluminium matrix composites. Design\\/methodology\\/approach: Aluminium matrix composites were produced employing the atomised aluminium alloy AA6061 as metal matrix, when as reinforcement TiAl and Ti3Al intermetallics particles were used. The powders were cold

  8. Spectroscopic diagnostics of plasma during laser processing of aluminium

    NASA Astrophysics Data System (ADS)

    Lober, R.; Mazumder, J.

    2007-10-01

    The role of the plasma in laser-metal interaction is of considerable interest due to its influence in the energy transfer mechanism in industrial laser materials processing. A 10 kW CO2 laser was used to study its interaction with aluminium under an argon environment. The objective was to determine the absorption and refraction of the laser beam through the plasma during the processing of aluminium. Laser processing of aluminium is becoming an important topic for many industries, including the automobile industry. The spectroscopic relative line to continuum method was used to determine the electron temperature distribution within the plasma by investigating the 4158 Å Ar I line emission and the continuum adjacent to it. The plasmas are induced in 1.0 atm pure Ar environment over a translating Al target, using f/7 and 10 kW CO2 laser. Spectroscopic data indicated that the plasma composition and behaviour were Ar-dominated. Experimental results indicated the plasma core temperature to be 14 000-15 300 K over the incident range of laser powers investigated from 5 to 7 kW. It was found that 7.5-29% of the incident laser power was absorbed by the plasma. Cross-section analysis of the melt pools from the Al samples revealed the absence of any key-hole formation and confirmed that the energy transfer mechanism in the targets was conduction dominated for the reported range of experimental data.

  9. Dietary exposure to aluminium and health risk assessment in the residents of Shenzhen, China.

    PubMed

    Yang, Mei; Jiang, Lixin; Huang, Huiping; Zeng, Shengbo; Qiu, Fen; Yu, Miao; Li, Xiaorong; Wei, Sheng

    2014-01-01

    Although there are great changes of dietary in the past few decades in China, few are known about the aluminium exposure in Chinese diet. The aim of this study is to systematically evaluate the dietary aluminium intake level in residents of Shenzhen, China. A total of 853 persons from 244 household were investigated their diet by three days food records. Finally, 149 kinds of foods in 17 food groups were selected to be the most consumed foods. From them, 1399 food samples were collected from market to test aluminium concentration. High aluminium levels were found in jellyfish (median, 527.5 mg/kg), fried twisted cruller (median, 466.0 mg/kg), shell (median, 107.1 mg/kg). The Shenzhen residents' average dietary aluminium exposure was estimated at 1.263 mg/kg bw/week which is lower than the PTWI (provisional tolerable weekly intake). But 0-2 and 3-13 age groups have the highest aluminium intake exceeding the PTWI (3.356 mg/kg bw/week and 3.248 mg/kg bw/week) than other age groups. And the main dietary aluminium exposure sources are fried twisted cruller, leaf vegetables and bean products. Our study suggested that even three decades rapid economy development, children in Shenzhen still have high dietary aluminium exposure risk. How to control high dietary aluminium exposure still is a great public health challenge in Shenzhen, China. PMID:24594670

  10. Galvanic interactions of aluminium 3004 and ? brass in tropical marine atmosphere

    NASA Astrophysics Data System (ADS)

    Palraj, S.; Subramanian, G.; Palanichamy, S.

    2014-12-01

    The galvanic corrosion behaviour of aluminium 3004 - ? brass with different area ratios was studied in the tropical marine atmosphere at Tuticorin harbour over a period of 426 days. The area ratios, viz. A Aluminium: A ? brass, studied were 0.125, 0.25, 0.5, 1, 2, 4 and 8. The galvanic corrosion behaviour of the metals was studied in terms of the relative increase in the corrosion rate of aluminium due to galvanic coupling with ? brass, the relative decrease in the corrosion rate of ? brass due to galvanic coupling with aluminium, and the susceptibility of aluminium to pitting owing to galvanic coupling with ? brass. The galvanic potential and galvanic current of the system were monitored. Pits of different dimensions ranging from mild etchings to perforations were experienced on the borders and the surfaces of the interface of aluminium in contact with ? brass. The corrosion products resulting from galvanic corrosion were analysed using XRD and the pitting on aluminium as a result of galvanic corrosion was highlighted in terms of pit depth, size and density of pit, using a high resolution microscope. The most favourable area ratio of aluminium — ? brass in marine atmosphere in terms of gravimetric corrosion rate is 8:1 and the most unfavourable area ratio of aluminium — ? brass is 1:4.

  11. Study of twin-roll cast Aluminium alloys subjected to severe plastic deformation by equal channel angular pressing

    NASA Astrophysics Data System (ADS)

    Poková, M.; Cieslar, M.

    2014-08-01

    Aluminium alloys prepared by twin-roll casting method become widely used in industry applications. Their high solid solution supersaturation and finer grains ensure better mechanical properties when compared with the direct-chill cast ones. One of the possibilities how to enhance their thermal stability is the addition of zirconium. After heat treatment Al3Zr precipitates form and these pin moving grain boundaries when the material is exposed to higher temperatures. In the present work twin-roll cast aluminium alloys based on AA3003 with and without Zr addition were annealed for 8 hours at 450 °C to enable precipitation of Al3Zr phase. Afterwards they were subjected to severe plastic deformation by equal channel angular pressing, which led to the reduction of average grain size under 1 ?m. During subsequent isochronal annealing recovery and recrystallization took place. These processes were monitored by microhardness measurements, light optical microscopy and in-situ transmission electron microscopy. The addition of Zr stabilizes the grain size and increases the recrystallization temperature by 100 °C.

  12. Rapid non-equilibrium aluminium-ligand interactions: studies on the precipitation of aluminium by laser light scattering, ultrafiltration and centrifugation.

    PubMed

    Jugdaohsingh, R; Salim, N; McCrohan, C R; White, K N; Thompson, R P; Powell, J J

    2001-11-01

    The study aimed to develop simple assays to study aluminium-ligand interactions in natural/biological systems where equilibrium is rarely reached and thus where the initial seconds or hours of interactions are important. The immediate and non-equilibrium precipitation of aluminium hydroxide, in aqueous solution at neutral pH, was therefore studied by laser light scattering (diffraction), ultrafiltration and centrifugation. The interaction of weak ligands, present in the gastrointestinal lumen, on the precipitation of aluminium hydroxide was also investigated. The initial kinetics and particle sizes of precipitated aluminium hydroxide were sensitive to a number of external factors, including the presence of weak ligand (bicarbonate), sheer force (stirring), electrolyte concentration and initial (i.e. added) aluminium concentration. However, after a few seconds (no weak ligand), or several hundred seconds (with weak ligand), the subsequent observed changes to the solid phase were of small magnitude and occurred slowly. Thus, a 25-min window, within 5 and 30 min of pH adjustment, can be used to study the interactions of aluminium-ligand. This may approximate better to most natural systems where unperturbed aluminium-ligand equilibrium must rarely exist. PMID:11709210

  13. The Tungsten Inert GAS (TIG) Process of Welding Aluminium in Microgravity: Technical and Economic Considerations

    NASA Astrophysics Data System (ADS)

    Ferretti, S.; Amadori, K.; Boccalatte, A.; Alessandrini, M.; Freddi, A.; Persiani, F.; Poli, G.

    2002-01-01

    The UNIBO team composed of students and professors of the University of Bologna along with technicians and engineers from Alenia Space Division and Siad Italargon Division, took part in the 3rd Student Parabolic Flight Campaign of the European Space Agency in 2000. It won the student competition and went on to take part in the Professional Parabolic Flight Campaign of May 2001. The experiment focused on "dendritic growth in aluminium alloy weldings", and investigated topics related to the welding process of aluminium in microgravity. The purpose of the research is to optimise the process and to define the areas of interest that could be improved by new conceptual designs. The team performed accurate tests in microgravity to determine which phenomena have the greatest impact on the quality of the weldings with respect to penetration, surface roughness and the microstructures that are formed during the solidification. Various parameters were considered in the economic-technical optimisation, such as the type of electrode and its tip angle. Ground and space tests have determined the optimum chemical composition of the electrodes to offer longest life while maintaining the shape of the point. Additionally, the power consumption has been optimised; this offers opportunities for promoting the product to the customer as well as being environmentally friendly. Tests performed on the Al-Li alloys showed a significant influence of some physical phenomena such as the Marangoni effect and thermal diffusion; predictions have been made on the basis of observations of the thermal flux seen in the stereophotos. Space transportation today is a key element in the construction of space stations and future planetary bases, because the volumes available for launch to space are directly related to the payload capacity of rockets or the Space Shuttle. The research performed gives engineers the opportunity to consider completely new concepts for designing structures for space applications. In fact, once the optimised parameters are defined for welding in space, it could be possible to weld different parts directly in orbit to obtain much larger sizes and volumes, for example for space tourism habitation modules. The second relevant aspect is technology transfer obtained by the optimisation of the TIG process on aluminium which is often used in the automotive industry as well as in mass production markets.

  14. Development of nano cerium oxide incorporated aluminium alloy sacrificial anode for marine applications

    Microsoft Academic Search

    S. M. A. Shibli; S. R. Archana; P. Muhamed Ashraf

    2008-01-01

    Aluminium–zinc alloy sacrificial anodes are extensively used for cathodic protection. The performance of the sacrificial anodes can be significantly improved by incorporation of microalloying elements in the aluminium matrix. In the present work nano cerium oxide particles of different concentrations, ranging from 0 to 1wt% were incorporated for activating and improving the performance of the anode. The electrochemical test results

  15. NUMERICAL VALIDATION OF A NEW FORMING PROCESS OF ALUMINIUM FINS FOR HEAT EXCHANGERS

    Microsoft Academic Search

    François Bilteryst; Jean-Louis Batoz; Mickael Grivel; Ivan Lewon; Ludovic Loison; Frédéric Mercier

    2004-01-01

    In a very competitive domain of design and manufacturing of multi-stream brazed aluminium plate-fin heat exchangers, the continuous challenge for a manufacturer such as Nordon Cryogenie (France) is to ensure an optimal brazing between the aluminium parting sheets and the fins in sandwich between those sheets. Fins are obtained from flat sheets by successive bending. It is therefore important to

  16. LES EMPLOIS DE L'ALUMINIUM EN LAITERIE, pHr M. E. DROUILLY,

    E-print Network

    Paris-Sud XI, Université de

    métal, alumines impures, connus sous le nom de bauxites rouges, sont particulièrement répandus sur notre'aluminium se prépare en enlevant à l'alumine son oxygène par I'électrolyse ; cette dernière opération se fait de remplacer les autres (1) Pour obtenir électriquement une tonne d'aluminium, il faut 2 tonnes d'alumine

  17. Corrosion properties of laser beam joints of aluminium with zinc-coated steel

    Microsoft Academic Search

    J. Wloka; H. Laukant; U. Glatzel; S. Virtanen

    2007-01-01

    This paper presents results of accelerated corrosion tests in a salt spray chamber as well as microelectrochemical measurements of thermally joint steel–aluminium mixed materials. The focus was set on analysing the corrosion behaviour of the different metallic materials (brazed seam, intermetallic phases, aluminium and steel sheet) in or within the vicinity of the brazed seam.Both corrosion tests show that the

  18. Temperature dependence of the tensile behaviour of aramid\\/aluminium laminates

    Microsoft Academic Search

    H. F. Wu

    1993-01-01

    Aramid\\/aluminium laminates (ARALL® laminates) are a family of new hybrid composites made of alternating layers of thin aluminium alloy sheets with plies of epoxy adhesive prepreg containing unidirectional aramid fibres. The effect of elevated and cryogenic temperatures on these materials is critical to aerospace applications. ARALL 1, 2, 3, and 4 laminates have been tested in tension at temperatures ranging

  19. A NOVEL CRUCIBLE METAL TREATMENT PRO CESS FOR IMPURITY REMOVAL lN SECONDARY ALUMINIUM

    Microsoft Academic Search

    Gaston Riverin; Jean-François Bilodeau; Claude Dupuis

    Treatment of aluminium in crucibles is weil established in the aluminium smelting industry as a very efficient technology to remove alkali elements such as lithium and sodium. The utilization of crucibles is a common tool in remelt and recycling plants to transport metal recovered from dross recycling and scrap melting operations. ln these cases, the metal is often contaminated with

  20. Importance of soil exchangeable cations and aluminium content on land snail distribution

    Microsoft Academic Search

    P. Ondina; S. Mato; J. Hermida; A. Outeiro

    1998-01-01

    The influence of soil exchangeable cations and aluminium content on the distribution of various terrestrial gastropods was investigated. Calcium was the most important factor, though aluminium and magnesium content also had some effect. Potassium and sodium had no significant influence on distribution. The species most sensitive to the factors analysed were Cochlicopa lubrica, Vertigo pygmaea and Carychium tridentatum.

  1. Analysis of manufacturing parameters on the shear strength of aluminium adhesive single-lap joints

    Microsoft Academic Search

    A. M. Pereira; J. M. Ferreira; F. V. Antunes; P. J. Bártolo

    2010-01-01

    An experimental and numerical investigation into the shear strength behaviour of aluminium alloy adhesive lap joints was carried out in order to understand the effect of geometrical and manufacturing parameters on the strength of adhesive bonding joints, with the aim of optimizing shear strength. The adherend material used for the experimental tests was an aluminium alloy in the form of

  2. ET-AAS determination of aluminium in dialysis concentrates after continuous flow solvent extraction

    Microsoft Academic Search

    J. Komárek; R. ?ervenka; T. R?ži?ka; V. Kubá?

    2007-01-01

    Conditions of a continuous flow extraction (CFE) of aluminium acetylacetonate in acetylacetone and aluminium 8-hydroxyquinolinate into methylisobutylketone (lengths of reaction and extraction coils, flow rates of aqueous and organic phases and their flow rate ratio, pH of aqueous phase, lengths of coils for transport of aqueous and organic phases and effect of salts) were studied. The analytical signal of the

  3. Chronic Toxicity of Aluminium in Rats and Mice and its Effects on Phosphorous Metabolism

    PubMed Central

    Ondrei?ka, R.; Ginter, E.; Kortus, J.

    1966-01-01

    In mice the oral LD50 values of aluminium chloride and aluminium sulphate were 0·77 ± 0·12 and 0·98 ± 0·09 g. Al/kg. (± S.E.) respectively. Mice and rats were fed on a normal diet containing about 170 p.p.m. of aluminium. Doubling this concentration caused a decrease in growth in the second and third generations of mice. A high intake of aluminium sulphate (2,835 p.p.m.) caused a 20-fold increase of aluminium retention in white rats. Aluminium accumulated in various tissues, especially in the skeleton, liver, and testes. A high rate of intake (2,665 p.p.m.) caused a negative phosphorus balance in the rat, with an increased output of phosphorus in the faeces. The lower absorption of phosphorus was also demonstrated with Na2H32PO4. Chronic and acute poisoning by aluminium chloride caused, after intraperitoneal Na2H32PO4, decreased incorporation of 32P into the phospholipids and nucleic acids of various tissues in the rat. It also caused a fall in the adenosinetriphosphate acid-levels in plasma, and a rise in the adenosine diphosphate level. The results suggest that the toxic effects of aluminium salts result both from decreased absorption of phosphorus and from interference with phosphorylation processes in the tissues. PMID:5926895

  4. Anomalous electric-field effect and glassy behaviour in granular aluminium thin films: electron glass?

    E-print Network

    Boyer, Edmond

    1 Anomalous electric-field effect and glassy behaviour in granular aluminium thin films: electron glass? T. Greneta , J. Delahaye, M. Sabra, F. Gay LEPES-CNRS, BP 166, 38042 Grenoble cedex 9, France Fax in granular aluminium thin films Abstract. We present a study of non-equilibrium phenomena observed

  5. The effects of aluminium and selenium supplementation on brain and liver antioxidant status in the rat

    Microsoft Academic Search

    M. G. ABUBAKAR; A. TAYLOR; G. A. FERNS

    2004-01-01

    This in vivo study was designed to investigate the potential of aluminium (Al), in the absence of added iron, to participate in either antioxidant or pro-oxidant events. Some markers of oxidative stress were determined in liver and brain of rats exposed to aluminium lactate, either alone or in the presence of dietary supplements of selenium (se) as selenite. Exposure to

  6. The wear of aluminium-based journal bearing materials under lubrication

    Microsoft Academic Search

    Erol Feyzullaho?lu; Nehir ?akiro?lu

    2010-01-01

    The aluminium-based alloys, nowadays, are developed to be used in high performance engine bearings. In this study, new Al-based bearing alloys, which are produced by metal mould casting, were developed; and tribologic properties of these alloys under lubrication were analyzed experimentally. Four different aluminium alloys were carried out on pin on disc wear tester for that purpose. SAE 1040 steel

  7. FROTTEMENT INTRIEUR HAUTES TEMPRATURES D'UN ALUMINIUM DE HAUTE PURET

    E-print Network

    Paris-Sud XI, Université de

    L-401 FROTTEMENT INTÉRIEUR HAUTES TEMPÉRATURES D'UN ALUMINIUM DE HAUTE PURETÉ C. ESNOUF, M. GABBAY N) un pic de frottement intérieur situé vers 0,5 TF (TF = température de fusion en K) dont l observed in high purity (6 N) polycrystalline aluminium an internal friction peak situated around 0.5 TF

  8. Spot diagnosis of aluminium phosphide ingestion: an application of a simple test.

    PubMed

    Chugh, S N; Ram, S; Chugh, K; Malhotra, K C

    1989-03-01

    Silver nitrate impregnated paper test was performed with the gastric fluid and in breath in 50 patients of aluminium phosphide poisoning. The test was 100% positive with gastric fluid but was positive in 50% patients in breath. The test is simple, reliable and sensitive method to detect phosphine (PH3) for bed side diagnosis of aluminium phosphide (AIP) ingestion. PMID:2768165

  9. Gum arabic as a potential corrosion inhibitor for aluminium in alkaline medium and its adsorption characteristics

    Microsoft Academic Search

    S. A. Umoren; I. B. Obot; E. E. Ebenso; P. C. Okafor; O. Ogbobe; E. E. Oguzie

    2006-01-01

    Purpose – To investigate the inhibitive effect of gum arabic (GA) for the corrosion of aluminium in alkaline (NaOH) medium and determine its adsorption characteristics. The present work is another trial to find a cheap and environmentally safe inhibitor for aluminium corrosion. Design\\/methodology\\/approach – The inhibition efficiency (%I) has been evaluated using the hydrogen evolution (via the gasometric assembly) and

  10. The fatigue strength of sandwich beams with an aluminium alloy foam core

    Microsoft Academic Search

    A.-M. Harte; N. A. Fleck; M. F. Ashby

    2001-01-01

    Sandwich beams with aluminium face sheets and an aluminium alloy foam core are tested in cyclic four point bend, and S–N fatigue curves are determined for the failure modes of face fatigue, core shear and core indentation. The operative failure mode is dictated by the relative fatigue strength of face sheets to core, and upon the geometry of the sandwich

  11. Successful treatment of acute aluminium phosphide poisoning: possible benefit of coconut oil

    Microsoft Academic Search

    Shahin Shadnia; Mojgan Rahimi; Abdolkarim Pajoumand; Mohammad-Hosein Rasouli; Mohammad Abdollahi

    2005-01-01

    Aluminium phosphide is used to control rodents and pests in grain storage facilities. It produces phosphine gas, which is a mitochondrial poison. Unfortunately, there is no known antidote for aluminium phosphide intoxication, but our recent experience with a case showed that rapid prevention of absorption by coconut oil might be helpful. In the present case, we used the same protocol

  12. Corrosion of Aluminium in Composite Cements Anthony Setiadi* and Neil B. Milestone

    E-print Network

    Sheffield, University of

    . The product of corrosion is less dense than the metal and hence it occupies more volume. This may leadCorrosion of Aluminium in Composite Cements Anthony Setiadi* and Neil B. Milestone Immobilisation of which may contain metals such as aluminium, magnesium and steel. Cements are used because

  13. Measuring the Thickness of Aluminium Alloy Thin Foils Using Electron Energy Loss Spectroscopy

    Microsoft Academic Search

    A. Bardal; K. Lie

    2000-01-01

    Combining electron energy loss spectroscopy and convergent beam electron diffraction measurements, we have determined the mean-free-path for inelastic electron scattering for four different aluminium alloys. Electron energy loss spectroscopy spectra were acquired with the transmission electron microscope in image mode, without any objective aperture inserted. The value for pure aluminium was determined as 119 ± 5nm at an incident electron

  14. In situ transmission electron microscopy observations of dislocation processes in ??-strengthened aluminium-lithium alloys

    Microsoft Academic Search

    Harald Rösner; Wei Liu; Eckhard Nembach

    1999-01-01

    Dislocation processes in ??-strengthened aluminium-rich aluminium-lithium alloys have been studied by transmission electron microscopy; thin foils have been tensile tested in the transmission electron microscope and the configurations of the dislocations and their glide have been observed under full load. The average radii r of the ?? precipitates and their volume fractions f have been varied independently: 5nm < r

  15. Aluminium nanohole arrays enhanced resonance Raman scattering spectra in the near ultraviolet region

    NASA Astrophysics Data System (ADS)

    Wu, YanQing; Dong, Bin

    2014-12-01

    Aluminium nanohole arrays with fixed diameter were fabricated by focused ion beam and the periodicities were turned. Aluminium nanohole arrays enhanced resonance Raman scattering spectra in the near ultraviolet region were studied experimentally and theoretically, which revealed that the SERRS enhancement factor was as high as 6 orders.

  16. Dry sliding wear of particulate-reinforced aluminium alloys against automobile friction materials

    Microsoft Academic Search

    G. J. Howell; A. Ball

    1995-01-01

    Two magnesium\\/silicon aluminium alloys each reinforced with 20 vol.% SiC particulates have been worn against three makes of automobile friction linings (brake pads). Two of the friction linings are commonly used against cast iron rotors in automobile braking systems while the third has been specifically formulated for use against aluminium metal matrix composite (MMC) brake rotors. Wear processes at the

  17. Are aluminium potroom workers at increased risk of neurological disorders?

    PubMed Central

    Sim, M; Dick, R; Russo, J; Bernard, B; Grubb, P; Krieg, E; Mueller, C; McCammon, C

    1997-01-01

    OBJECTIVE: To determine whether long term potroom workers in an aluminium smelter are at increased risk of neurological disorders. METHODS: Cross sectional study of 63 current and former aluminium potroom workers first employed before 1970 and with at least 10 years of service. A group of 37 cast house and carbon plant workers with similar durations of employment and starting dates in the same smelter were used as controls. The prevalence of neurological symptoms was ascertained by questionnaire. Objective tests of tremor in both upper and lower limbs, postural stability, reaction time, and vocabulary were conducted. All subjects were examined by a neurologist. RESULTS: No significant differences in age, race, or education were found between the two groups. Although the potroom group had higher prevalences for all but one of the neurological symptoms, only three odds ratios (ORs) were significantly increased; for incoordination (OR 10.6), difficulty buttoning (OR 6.2), and depression (OR 6.2). Tests of arm or hand and leg tremor in both the visible and non-visible frequencies did not show any significant differences between the two groups. Testing of postural stability showed no definitive pattern of neurologically meaningful differences between the groups. There were no significant differences between the two groups in reaction time, vocabulary score, or clinical neurological assessment. CONCLUSIONS: The objective measures of neurological function provided little support for the finding of increased neurological symptom prevalences in the potroom workers, although increased symptoms may be an indicator of early, subtle neurological changes. The results provide no firm basis for concluding that neurological effects among long term potroom workers are related to the working environment, in particular aluminium exposure, in potrooms. These findings should be treated with caution due to the low participation of former workers and the possibility of information bias in the potroom group. PMID:9166127

  18. Aluminium control of argon solubility in silicate melts under pressure.

    PubMed

    Bouhifd, M Ali; Jephcoat, Andrew P

    2006-02-23

    Understanding of the crystal chemistry of the Earth's deep mantle has evolved rapidly recently with the gradual acceptance of the importance of the effect of minor elements such as aluminium on the properties of major phases such as perovskite. In the early Earth, during its formation and segregation into rocky mantle and iron-rich core, it is likely that silicate liquids played a large part in the transport of volatiles to or from the deep interior. The importance of aluminium on solubility mechanisms at high pressure has so far received little attention, even though aluminium has long been recognized as exerting strong control on liquid structures at ambient conditions. Here we present constraints on the solubility of argon in aluminosilicate melt compositions up to 25 GPa and 3,000 K, using a laser-heated diamond-anvil cell. The argon contents reach a maximum that persists to pressures as high as 17 GPa (up to 500 km deep in an early magma ocean), well above that expected on the basis of Al-free melt experiments. A distinct drop in argon solubility observed over a narrow pressure range correlates well with the expected void loss in the melt structure predicted by recent molecular dynamics simulations. These results provide a process for noble gas sequestration in the mantle at various depths in a cooling magma ocean. The concept of shallow partial melting as a unique process for extracting noble gases from the early Earth, thereby defining the initial atmospheric abundance, may therefore be oversimplified. PMID:16495996

  19. The fracture of boron fibre-reinforced 6061 aluminium alloy

    NASA Technical Reports Server (NTRS)

    Wright, M. A.; Welch, D.; Jollay, J.

    1979-01-01

    The fracture of 6061 aluminium alloy reinforced with unidirectional and cross-plied 0/90 deg, 0/90/+ or - 45 deg boron fibres has been investigated. The results have been described in terms of a critical stress intensity, K(Q). Critical stress intensity factors were obtained by substituting the failure stress and the initial crack length into the appropriate expression for K(Q). Values were obtained that depended on the dimensions of the specimens. It was therefore concluded that, for the size of specimen tested, the values of K(Q) did not reflect any basic materials property.

  20. Foaming of aluminium-silicon alloy using concentrated solar energy

    SciTech Connect

    Cambronero, L.E.G.; Ruiz-Roman, J.M. [Grupo de Materiales Hibridos, ETSIM-UPM, Madrid, Rios Rosas 21, 28003 Madrid (Spain); Canadas, I.; Martinez, D. [Plataforma Solar de Almeria, CIEMAT, P.O. Box 22, 04200 Tabernas (Almeria) (Spain)

    2010-06-15

    Solar energy is used for the work reported here as a nonconventional heating system to produce aluminium foam from Al-Si alloy precursors produced by powder metallurgy. A commercial precursor in cylindrical bars enclosed in a stainless-steel mould was heated under concentrated solar radiation in a solar furnace with varied heating conditions (heating rate, time, and temperature). Concentrated solar energy close to 300 W/cm{sup 2} on the mould is high enough to achieve complete foaming after heating for only 200 s. Under these conditions, the density and pore distribution in the foam change depending on the solar heating parameters and mould design. (author)

  1. Modeling of recrystallization texture of aluminium: symmetric and asymmetric rolling

    NASA Astrophysics Data System (ADS)

    Wierzbanowski, K.; Kotra, M.; Wronski, M.; Sztwiertnia, K.; Wronski, S.; Lodini, A.

    2015-04-01

    In some metallic materials the dominating recrystallization mechanism can be described by the oriented growth behaviour. Phenomenological laws state that in selected materials only these nuclei grow intensively which have a given misorientation relation with the deformed matrix. This description is frequently verified in f.c.c. metals and generally reported misorientations correspond approximately to 400 rotation around the <111> axis. Basing on the above ideas the recrystallization model, including the compromise condition, was formulated and applied to the study of recrystallization textures of rolled polycrystalline aluminium.

  2. Deviatoric Response of AN Armour-Grade Aluminium Alloy

    NASA Astrophysics Data System (ADS)

    Appleby-Thomas, G. J.; Hazell, P. J.; Millett, J.; Bourne, N. K.

    2009-12-01

    Aluminium alloys such as 5083 H32 are established light-weight armour materials. As such, the shock response of these materials is of great importance. The shear strength of a material under shock loading provides an insight into its ballistic performance. In this investigation embedded manganin stress gauges have been employed to measure both the longitudinal and lateral components of stress during plate-impact experiments over a range of impact stresses. In turn, these results were used to determine the shear strength and to investigate the time dependence of lateral stress behind the shock front to give an indication of material response.

  3. Electrochemical lithium intercalation in lead–tin–aluminium solder

    Microsoft Academic Search

    Atanaska V. Trifonova; Anton A. Momchilov; Bogdana L. Puresheva; Isaac Abrahams

    2001-01-01

    Electrochemical lithiation in a lead–tin–aluminium (ca. 1:2:1 atomic ratio) solder has been examined with a view to possible use as an anode material in Li-ion batteries. Electrochemical tests were carried out in a three-electrode laboratory metal cell against a lithium metal anode. The electrolyte used was 0.8 M LiPF6+0.2 M LiClO4 in ethylene carbonate\\/dimethyl carbonate\\/diethyl carbonate in the volume ratio

  4. High-Rate Compaction of Aluminium Alloy Foams

    SciTech Connect

    Harrigan, J. J.; Hung, Y.-C.; Tan, P. J.; Bourne, N. K.; Withers, P. J.; Reid, S. R. [University of Manchester, PO Box 88, Sackville Street, Manchester M60 1QD (United Kingdom); Millett, J. C. F. [Defence Academy of the UK, Cranfield University, Shrivenham, Swindon, SN6 8LA (United Kingdom); Milne, A. M. [Fluid Gravity Engineering, 83 Market Street, St. Andrews, Fife, KY16 9NX (United Kingdom)

    2006-07-28

    The response of aluminium foams to impact can be categorised according to the impact velocity. Tests have been carried out at a range of impact velocities from quasi-static to velocities approaching the speed of sound in the foam. Various experimental arrangements have been employed including pneumatic launcher tests and plate impact experimants at velocities greater than 1000 m s-1. The quasi-static compression behaviour was approximately elastic, perfectly-plastic, locking. For static and dynamic compression at low impact velocities the deformation pattern was through the cumulative multiplication of discrete, non-contiguous crush bands. Selected impact tests are presented here for which the impact velocity is less than the velocity of sound, but above a certain critical impact velocity so that the plastic compression occurs in a shock-like manner and the specimens deform by progressive cell crushing. Laboratory X-ray microtomography has been employed to acquire tomographic datasets of aluminium foams before and after tests. The morphology of the underformed foam was used as the input dataset to an Eulerian code. Hydrocode simulations were then carried out on a real microstructure. These simulations provide insight to mechanisms associated with the localization of deformation.

  5. Fabrication of superhydrophobic aluminium alloy surface with excellent corrosion resistance by a facile and environment-friendly method

    NASA Astrophysics Data System (ADS)

    Feng, Libang; Che, Yanhui; Liu, Yanhua; Qiang, Xiaohu; Wang, Yanping

    2013-10-01

    This work develops a facile and environment-friendly method for preparing the superhydrophobic aluminium alloy surface with excellent corrosion resistance. The superhydrophobic aluminium alloy surface is fabricated by the boiling water treatment and stearic acid (STA) modification. Results show that the boiling water treatment endows the aluminium alloy surface with a porous and rough structure, while STA modification chemically grafts the long hydrophobic alkyl chains onto the aluminium alloy surface. Just grounded on the micro- and nano-scale hierarchical structure along with the hydrophobic chemical composition, the superhydrophobic aluminium alloy surface is endued the excellent corrosion resistance.

  6. Effects on the nervous system among welders exposed to aluminium and manganese.

    PubMed Central

    Sjögren, B; Iregren, A; Frech, W; Hagman, M; Johansson, L; Tesarz, M; Wennberg, A

    1996-01-01

    OBJECTIVES--The purpose was to study the effects on the nervous system in welders exposed to aluminium and manganese. METHODS--The investigation included questionnaires on symptoms, psychological methods (simple reaction time, finger tapping speed and endurance, digit span, vocabulary, tracking, symbol digit, cylinders, olfactory threshold, Luria-Nebraska motor scale), neurophysiological methods (electroencephalography, event related auditory evoked potential (P-300), brainstem auditory evoked potential, and diadochokinesometry) and assessments of blood and urine concentrations of metals (aluminium, lead, and manganese). RESULTS--The welders exposed to aluminium (n = 38) reported more symptoms from the central nervous system than the control group (n = 39). They also had a decreased motor function in five tests. The effect was dose related in two of these five tests. The median exposure of aluminium welders was 7065 hours and they had about seven times higher concentrations of aluminium in urine than the controls. The welders exposed to manganese (n = 12) had a decreased motor function in five tests. An increased latency of event related auditory evoked potential was also found in this group. The median manganese exposure was 270 hours. These welders did not have higher concentrations of manganese in blood than the controls. CONCLUSIONS--The neurotoxic effects found in the groups of welders exposed to aluminium and manganese are probably caused by the aluminium and manganese exposure, respectively. These effects indicate a need for improvements in the work environments of these welders. PMID:8563855

  7. Derivation of a water quality guideline for aluminium in marine waters.

    PubMed

    Golding, Lisa A; Angel, Brad M; Batley, Graeme E; Apte, Simon C; Krassoi, Rick; Doyle, Chris J

    2015-01-01

    Metal risk assessment of industrialized harbors and coastal marine waters requires the application of robust water quality guidelines to determine the likelihood of biological impacts. Currently there is no such guideline available for aluminium in marine waters. A water quality guideline of 24?µg total Al/L has been developed for aluminium in marine waters based on chronic 10% inhibition or effect concentrations (IC10 or EC10) and no-observed-effect concentrations (NOECs) from 11 species (2 literature values and 9 species tested including temperate and tropical species) representing 6 taxonomic groups. The 3 most sensitive species tested were a diatom Ceratoneis closterium (formerly Nitzschia closterium; IC10?=?18?µg Al/L, 72-h growth rate inhibition) < mussel Mytilus edulis plannulatus (EC10?=?250?µg Al/L, 72-h embryo development) < oyster Saccostrea echinata (EC10?=?410?µg Al/L, 48-h embryo development). Toxicity to these species was the result of the dissolved aluminium forms of aluminate (Al(OH4 (-) ) and aluminium hydroxide (Al(OH)3 (0) ) although both dissolved, and particulate aluminium contributed to toxicity in the diatom Minutocellus polymorphus and green alga Dunaliella tertiolecta. In contrast, aluminium toxicity to the green flagellate alga Tetraselmis sp. was the result of particulate aluminium only. Four species, a brown macroalga (Hormosira banksii), sea urchin embryo (Heliocidaris tuberculata), and 2 juvenile fish species (Lates calcarifer and Acanthochromis polyacanthus), were not adversely affected at the highest test concentration used. PMID:25318392

  8. Influence of Nano Aluminium Powder Produced by Wire Explosion Process at Different Ambience on Hydrogen Generation

    NASA Astrophysics Data System (ADS)

    Sarathi, Ramanujam; Sankar, Binu; Chakravarthy, Satyanarayanan R.

    2010-07-01

    Nano-aluminium particles are produced through the wire explosion process in different gas medium. The particles produced by wire explosion process, in helium medium are of smaller size compared to argon/nitrogen medium. The nano aluminium powder on reaction with water forms oxides having bayerite and boehmite structure. It is observed that nano aluminium on reaction with KOH solution at room temperature it forms bayerite. The results of the study were confirmed through Wide Angle X-ray diffraction (WAXD) and by Transmission Electron Microscope (TEM) studies. The reaction of nano aluminium powder with KOH solution/water indicates that the rate of hydrogen generation is high when nano aluminium powder reacts with KOH solution than with water. The rate of hydrogen generation gets reduced drastically when the nano aluminium powder which is exposed to air medium for some period is used for reaction with KOH/water. It is also observed that the rate of hydrogen generation is high with nano size aluminium particles compared with ultrafine particles.

  9. Increasing aluminium concentrations in Southwest Nova Scotia Canada rivers from 1980 to present

    NASA Astrophysics Data System (ADS)

    Minichiello, Jeff; Sterling, Shannon; Ambrose, Sarah; Clair, Tom

    2014-05-01

    Elevated aluminum levels in rivers is known to be toxic for aquatic species, in particular Salmo salar; however it was only recently aluminium has been identified as a potential threat to Salmo salar populations in South Western Nova Scotia, Canada (SWNS) (Dennis and Clair 2012). Previously, it was thought SWNS rivers contained enough DOC to render the aluminium in rivers inactive. A key remaining question is whether aluminium levels are declining following atmospheric pollution reductions. Here we make a first assessment of long term (1980-2011) aluminium concentration trends in three watersheds located in SWNS, as measured by weekly grab samples. Our results show that total aluminium levels have significantly increased from 1980-2011 in all three sites. Estimates of ionic aluminium levels indicate that the ionic aluminum concentration frequently exceeds the threshold for the level of aquatic health determined by the European Inland Fisheries Advisory Commission (Howells et al. 1990). Data also indicates that calcium levels have yet to recover even with declining concentrations of riverine sulfate. This new knowledge that aluminium is at toxic levels and is worsening will have implications for policy on acidification mitigation in SWNS; this is an urgent issue as the local salmon population numbers currently are declining to near extirpation levels.

  10. Increased absorption of aluminium from a normal dietary intake in dementia.

    PubMed

    Roberts, N B; Clough, A; Bellia, J P; Kim, J Y

    1998-02-15

    Serum aluminium was significantly raised (p < 0.01) up to 2-3-fold, in patients with dementia including Alzheimers Disease (AD) 0.66 +/- 0.2 (mumol/l mean +/- 1 s.d.) and patients on regular aluminium hydroxide therapy 0.54 +/- 0.17, compared with healthy volunteers 0.21 +/- 0.13, although not as high as in patients with end stage renal failure on regular dialysis 0.88 +/- 0.42. The urine outputs (mumol/l mean +/- 1 s.d.) of aluminium and silicon, respectively, were also significantly increased up to 5-fold in dementia 2.89 +/- 1.78 (n = 23) and 1587 +/- 645 (n = 22) and patients on regular aluminium hydroxide therapy 5.03 +/- 2.08 (n = 8) and 998 +/- 364 (n = 21) compared with healthy volunteers 0.95 +/- 0.82 (n = 84) and 471 +/- 332 (n = 114). The increase in urine aluminium was thus associated with a similarly marked increase in the output of silicon. The increased absorption of aluminium in dementia patients is equivalent to the intestinal loading in Aludrox therapy. Also silicon appears to be important in the renal excretion of the absorbed aluminium. Whether this is a phenomenon related to the elderly or the process of dementia warrants further study. PMID:9629676

  11. Application of Minkowski layer for intergranular fractal surfaces of multiphase active microalloyed and alloyed aluminium-silicate ceramics

    NASA Astrophysics Data System (ADS)

    Purenovi?, J. M.; Randjelovi?, M. S.; Matovi?, B. Z.; Purenovi?, M. M.

    2015-03-01

    Microalloyed and alloyed aluminium-silicate ceramics represents multiphase and multifunctional solid-solid system. The microstructure of aluminium-silicate ceramics matrix is arranged with favorable relationship between crystallinity and amorphousness. Numbered physical processes and interactions take place in very complex intergranular and interphase areas, making new boundaries and regions with fractal nature. Fractal nature of grains contours, macro, mezzo and micro pores and nanostructure phases at grain boundaries make this ceramics an active dielectric material. The synergistic effect of additives, dislocations and impurities leads to dislocations movement at grain boundaries and fragmentation of existing grains in a large number of micrograins with distinct fractal nature. Hence, permanent change of micromorphology occurs in intergranular area. Fractal analysis of intergranular microstructure has included application of Minkowski layer, correlated with fractal dimension. It represents convex layer of grains contour roughness and irregularity, determined in accordance with grain contours fractality. The introduction of fractal microstructure analysis allows better interpretation of many physical and physico-chemical processes, bearing in mind that Minkowski layer defines grains contact probability.

  12. Car-Parrinello Simulation of the Aluminium Oxidation: Questioning the Role of 'Hot Adatoms'

    E-print Network

    Schulte, Marius

    2012-01-01

    We present Car-Parrinello molecular dynamics simulations of the initial reaction steps leading to an inert oxide layer on aluminium. The mechanism of the reaction of the aluminium surface with single oxygen molecules is analysed. After adsorption at the surface the oxygen molecules dissociate at a femtosecond timescale and the atoms are chemisorbed at the surface at a distance of several angstrom which falsifies earlier STM results. When the aluminium surface is exposed to higher oxygen pressure, a surface layer essentially consisting of threefold coordinated oxygen atoms starts to form.

  13. Pulmonary Fibrosis in Workers Exposed to Finely Powdered Aluminium

    PubMed Central

    Mitchell, John; Manning, G. B.; Molyneux, M.; Lane, Ronald E.

    1961-01-01

    Of 30 workmen at risk 27 were examined and six found to have evidence of pulmonary fibrosis. In the two fatal cases the evidence for pulmonary fibrosis was conclusive and in three other cases it was sufficient; in one case it was suggestive. The clinical, radiological, and pathological features of these six cases are recorded. Results of respiratory function tests on the four non-fatal cases are given. The manufacturing process is described. An analysis of the powder is given, also the results of dust measurement in the contaminated atmosphere. The literature is reviewed and our own experience compared with reports from Germany and Canada. We concluded that the pulmonary fibrosis was caused by the dust inhaled at work and that the component responsible was finely divided aluminium. Images PMID:13771334

  14. Synthesis and characterization of luminescent aluminium selenide nanocrystals

    SciTech Connect

    Balitskii, O.A., E-mail: balitskii@electronics.wups.lviv.ua [Department of Electronics, Lviv Ivan Franko National University, Dragomanov Str., 50, 79005 Lviv (Ukraine); Demchenko, P.Yu. [Department of Chemistry, Lviv Ivan Franko National University, Kyryla and Mefodiya 6, 79005 Lviv (Ukraine)] [Department of Chemistry, Lviv Ivan Franko National University, Kyryla and Mefodiya 6, 79005 Lviv (Ukraine); Mijowska, E.; Cendrowski, K. [Centre of Knowledge Based Nanomaterials and Technologies, Institute of Chemical and Environmental Engineering, West Pomeranian University of Technology, 10, Pulaskiego Str., Szczecin 70-322 (Poland)] [Centre of Knowledge Based Nanomaterials and Technologies, Institute of Chemical and Environmental Engineering, West Pomeranian University of Technology, 10, Pulaskiego Str., Szczecin 70-322 (Poland)

    2013-02-15

    Highlights: ? Synthesis procedure of size and sharp controlled Al{sub 2}Se{sub 3} nanocrystals is introduced. ? Obtained nanoparticles are highly crystalline of hexagonal wurtzite type. ? Colloidal Al{sub 2}Se{sub 3} nanocrystals are highly luminescent in the near UV spectral region. ? They can be implemented in light emitters/collectors, concurring with II–VI nanodots. -- Abstract: We propose the synthesis and characterization of colloidal aluminium selenide nanocrystals using trioctylphosphine as a solvent. The nanoparticles have several absorption bands in the spectral region 330–410 nm and are bright UV-blue luminescent, which is well demanded in light collecting and emitting devices, e.g. for tuning their spectral characteristics to higher energy solar photons.

  15. Unusual sources of aluminium and heavy metals in potable waters.

    PubMed

    Fuge, R; Pearce, N J; Perkins, W T

    1992-04-01

    Aluminium in water supplies derives from natural sources and from the use of Al2(SO4)3 in water treatment. Heavy metals such as Pb, Cu, Zn and Cd can be added to water from pipework and solder. However, it is apparent that AI and other metals in potable waters can derive from deposits on pipe walls which can be subsequently mobilised when the supply and/or treatment process is changed. Concentrations of Al in domestic supply water of the Llanbrynmair area have been shown to increase from 1 ?g to 50 ?g L(-1) during its 18 km journey along the water main. Similarly, Pb concentrations in a public building in the Aberystwyth area are found to be extremely elevated due to the metal's mobilisation from encrustations occurring on the copper pipework. PMID:24197897

  16. addition and subtraction

    NSDL National Science Digital Library

    Ms. Hayes

    2011-04-07

    How are addition and subtraction problems related? Recording chart Graphic Organizer Use this link to work on addition with pictures. addition with pictures Go here to work on addition with sentences. addition with sentences Now, go here to work on subtraction sentences. Subtraction sentences Use this link to practice subtraction with pictures. Subtraction with pictures Now let's review! Click here. Fact Family Practice ...

  17. In end-stage renal failure, does infection lead to elevated plasma aluminium and neurotoxicity? Implications for monitoring.

    PubMed

    Fenwick, Sean; Roberts, Edward A; Mahesh, Balakrishna S; Roberts, Norman B

    2005-03-01

    The well-described long-term effects of sustained exposure to aluminium in patients with end-stage renal failure (ESRF) are a result of uptake and storage of aluminium, leading to cellular toxicity. A case is presented suggesting that this aluminium may be mobilizable, and indicating the consequence of such release. A patient on haemodialysis (HD) presented acutely with infection, a raised CRP, decreased conscious level, impaired cognition and agitation. Subsequent neurological recovery over six to seven days appeared to follow the return of markedly elevated plasma aluminium concentrations to basal (i.e. from 25.2 micromol/L to 2.5 micromol/L; reference range < 0.5 micromol/L), coupled with a resolution of the infection. The patient was on long-term aludrox therapy 3 g/day, and showed relative resistance to the exogenous hormone erythropoietin, resulting in a refractory anaemia and suggesting aluminium toxicity. A series of HD patients (n = 5) presenting with bacteraemia, not on aludrox, showed no appreciable rise in the plasma aluminium mean of 1.3 micromol/L (SD 0.9; range 0.6-2.0 micromol/L). We suggest that infection can result in release of tissue aluminium, leading to acutely elevated plasma aluminium concentrations and signs of neurotoxicity. The amount of tissue storage and resultant aluminium release seemed to be related to the use of aluminium hydroxide as a phosphate binder. PMID:15829127

  18. Preparation of Wollastonite Coated with Nano-Aluminium Silicate and its Application in Filling PA6

    NASA Astrophysics Data System (ADS)

    Wang, Caili; Zheng, Shuilin; Liu, Guihua; Wang, Lijing; Huang, Peng; Wang, Zhaohua

    Taking wollastonite as raw material, aluminium sulfate and water glass as coating modifier, a new type of wollastonite coated with nano-aluminium silicate powder-materials was obtained by chemical depositing method. By modificating this powder-materials with silane and filling it in PA6, the PA6 composite materials were obtained. The modificated powder-materials were characterized by SEM, BET, XRD, EDX, and FT-IR. The mechanism of this powder-materials modificated by silane was discussed. It was shown that the surface of wollastonite was coated with nano-aluminium silicate evenly, the average grain size of aluminium silicate was 54 nm, filling 30% of this powder-materials modified by silane in PA6, the mechanical properties and the heat distortion temperature of the PA6 composites filled by it were notably enhanced.

  19. Determining the location and nearest neighbours of aluminium in zeolites with atom probe tomography

    PubMed Central

    Perea, Daniel E.; Arslan, Ilke; Liu, Jia; Ristanovi?, Zoran; Kovarik, Libor; Arey, Bruce W.; Lercher, Johannes A.; Bare, Simon R.; Weckhuysen, Bert M.

    2015-01-01

    Zeolite catalysis is determined by a combination of pore architecture and Brønsted acidity. As Brønsted acid sites are formed by the substitution of AlO4 for SiO4 tetrahedra, it is of utmost importance to have information on the number as well as the location and neighbouring sites of framework aluminium. Unfortunately, such detailed information has not yet been obtained, mainly due to the lack of suitable characterization methods. Here we report, using the powerful atomic-scale analysis technique known as atom probe tomography, the quantitative spatial distribution of individual aluminium atoms, including their three-dimensional extent of segregation. Using a nearest-neighbour statistical analysis, we precisely determine the short-range distribution of aluminium over the different T-sites and determine the most probable Al–Al neighbouring distance within parent and steamed ZSM-5 crystals, as well as assess the long-range redistribution of aluminium upon zeolite steaming. PMID:26133270

  20. Determining the location and nearest neighbours of aluminium in zeolites with atom probe tomography.

    PubMed

    Perea, Daniel E; Arslan, Ilke; Liu, Jia; Ristanovi?, Zoran; Kovarik, Libor; Arey, Bruce W; Lercher, Johannes A; Bare, Simon R; Weckhuysen, Bert M

    2015-01-01

    Zeolite catalysis is determined by a combination of pore architecture and Brønsted acidity. As Brønsted acid sites are formed by the substitution of AlO4 for SiO4 tetrahedra, it is of utmost importance to have information on the number as well as the location and neighbouring sites of framework aluminium. Unfortunately, such detailed information has not yet been obtained, mainly due to the lack of suitable characterization methods. Here we report, using the powerful atomic-scale analysis technique known as atom probe tomography, the quantitative spatial distribution of individual aluminium atoms, including their three-dimensional extent of segregation. Using a nearest-neighbour statistical analysis, we precisely determine the short-range distribution of aluminium over the different T-sites and determine the most probable Al-Al neighbouring distance within parent and steamed ZSM-5 crystals, as well as assess the long-range redistribution of aluminium upon zeolite steaming. PMID:26133270

  1. Sur le frottement intérieur observé a températures moyennes dans un aluminium de haute pureté

    Microsoft Academic Search

    J. Friedel

    1978-01-01

    The strong peak of internal friction observed at medium temperatures in a high purity aluminium is attributed to the shift by cross-slip of the nodes of polygonized walls. Further experiments could check this proposal. Tome 39

  2. Non-aqueous aluminium-air battery based on ionic liquid electrolyte

    NASA Astrophysics Data System (ADS)

    Revel, Renaud; Audichon, Thomas; Gonzalez, Serge

    2014-12-01

    A promising metal-air secondary battery based on aluminium-oxygen couple is described. In this paper, we observed that an aluminium-air battery employing EMImCl, AlCl3 room temperature ionic liquid (RTIL) as electrolyte and aluminium as negative electrode, has an exceptional reduced self-discharged rate. Due to its new and innovative type of electrolyte, this aluminium-air battery can support relatively high current densities (up to 0.6 mA cm-2) and an average voltage of 0.6-0.8 V. Such batteries may find immediate applications, as they can provide an internal, built-in autonomous and self-sustained energy source.

  3. Microstructure and mechanical properties of wrought aluminium alloy prepared by recycling of aluminium matrix composites reinforced with Inconel 601 fibres

    Microsoft Academic Search

    J Lapin; T Pelachová

    1999-01-01

    The microstructure and mechanical properties of Al-2.2Cu-1.7Mg-1.1Ni-1.1Fe-0.9Si-0.3Zn-0.2Cr-0.2Mn-0.2Ti (wt.%) alloy prepared by recycling of composite scrap containing Inconel 601 fibres in aluminium matrix were investigated. The structure of recycled alloy consisted of ?-Al dendrites and a multiphase interdendritic region. Transmission electron microscopy and energy dispersive X-ray spectroscopy showed that the interdendritic region contained coarse Al9Fe(Ni, Si), Al7Cu4Ni, Al4CuMg5Si4, (Cu, Al)2Mg and

  4. Effect of pulsed current welding on fatigue behaviour of high strength aluminium alloy joints

    Microsoft Academic Search

    V. Balasubramanian; V. Ravisankar; G. Madhusudhan Reddy

    2008-01-01

    High strength aluminium alloys (Al–Zn–Mg–Cu alloys) have gathered wide acceptance in the fabrication of light weight structures requiring high strength-to weight ratio, such as transportable bridge girders, military vehicles, road tankers and railway transport systems. The preferred welding processes of high strength aluminium alloy are frequently gas tungsten arc welding (GTAW) process and gas metal arc welding (GMAW) process due

  5. Study on the mechanism of the reaction of NO 2 with aluminium oxide

    Microsoft Academic Search

    N Apostolescu; T Schröder; S Kureti

    2004-01-01

    In this study, the reaction of NO2 with aluminium oxide is examined. Aluminium oxide is an important component of NOx storage catalysts (NSC) that are used for the removal of nitrogen oxides from the exhaust gas of lean burn engines. Temperature-programmed desorption (TPD), diffuse reflectance infrared Fourier transformation spectroscopy (DRIFTS) and continuous analysis of gas-phase products are used in order

  6. Effect of aluminium and sulphate on anaerobic digestion of sludge from wastewater enhanced primary treatment

    Microsoft Academic Search

    N. Cabirol; E. J. Barragán; A. Durán; A. Noyola

    2003-01-01

    The combined and individual effects of aluminium and sulphate at concentrations of 1,000 mg\\/l as Al(OH)3, and 150 mgSO42-\\/L as K2SO4, respectively, on the anaerobic digestion of sludge from enhanced primary treatment (EPT) were evaluated in 1 L capacity semi continuous reactors. It was found that at 59 days, aluminium inhibits the specific methanogenic activity (SMA) of methanogenic and acetogenic

  7. Influence of the co-precipitation temperature on phase evolution in yttrium-aluminium oxide materials

    Microsoft Academic Search

    Paola Palmero; Claude Esnouf; Laura Montanaro; Gilbert Fantozzi

    2005-01-01

    Yttrium-aluminium garnet (YAG) powders were synthesized using a reverse-strike precipitation, by adding an aqueous solution of yttrium and aluminium chlorides to dilute ammonia while monitoring the pH to a constant value of 9. After precipitation, the gelly product was washed with dilute ammonia and absolute ethanol for avoiding hard agglomeration during drying. Precipitation and washing procedures were performed at three

  8. Effects of Shielding Gas on Absorption Energy of Nd-YAG Laser for Aluminium Welding

    SciTech Connect

    Mutlu, M.; Akman, E.; Demir, A. [University of Kocaeli, Laser Technologies Research and Application Center, Kocaeli (Turkey)

    2007-04-23

    Aluminium is the one of the most abundant element situated in Earth's crust and using in thousands of industrial applications. In this study spectroscopic analysis for 1mm thick aluminium plates investigated and electron temperatures were calculated with using emission spectra obtained from plasma. The relation between electron temperature and shielding gas pressure, type, pulse energy, beam focus position and flow direction were observed. With using shielding gases Ar, He, N2 at different pressures the bead widths was measured.

  9. Endurance limit and threshold stress intensity of die cast magnesium and aluminium alloys at elevated temperatures

    Microsoft Academic Search

    H. Mayer; M. Papakyriacou; B. Zettl; S. Vacic

    2005-01-01

    High cycle fatigue properties of the high-pressure die-cast magnesium alloys AZ91 hp, AS21 hp and AE42 hp and of the aluminium alloy AlSi9Cu3 are investigated at elevated temperatures. Fatigue tests are performed at ultrasonic cyclic frequency and load ratio R=?1. Compared with ambient air environment, the S–N curves determined in warm air of 125°C (magnesium alloys) and 150°C (aluminium alloy)

  10. Corrosion of unglazed rough graphite-aluminium solar absorber surfaces in simulated acid and neutral rain

    Microsoft Academic Search

    P. Konttinen; T. Salo; P. D. Lunda

    Degradation mechanisms of unglazed solar absorber surfaces based on aluminium substrate were studied. Rough graphite-aluminium surfaces were total-immersion subjected to aerated and de-aerated simulated neutral and acid rain. Test conditions were based on calculated absorber stagnation temperature and global rain acidity measurements. Changes in optical properties, elemental composition and sample mass were examined by spectrometry, energy dispersive X-ray spectrometry and

  11. Electron Conditioning of Technical Aluminium Surfaces: Effect on the Secondary Electron Yield

    Microsoft Academic Search

    F. King; R. E. Kirby; M. Pivi

    2004-01-01

    The effect of electron conditioning on commercially aluminium alloys 1100 and\\u000a6063 were investigated. Contrary to the assumption that electron conditioning,\\u000aif performed long enough, can reduce and stabilize the SEY to low values ($\\\\leq\\u000a1.3$, value of many pure elements), the SEY of aluminium did not go lower than\\u000a1.8. In fact, it reincreases with continued electron exposure dose.

  12. Highly aluminium doped barium and strontium ferrite nanoparticles prepared by citrate auto-combustion synthesis

    Microsoft Academic Search

    Neil J.. Shirtcliffe; Simon Thompson; Eoin S. O’Keefe; Steve Appleton; Carole C.. Perry

    2007-01-01

    Aluminium doped barium and strontium hexaferrite nanoparticles BaAlxFe(12?x)O19 and SrAlxFe(12?x)O19 were synthesised via a sol–gel route using citric acid to complex the ions followed by an auto-combustion reaction. This method shows promise for the synthesis of complex ferrite powders with small particle size. It was found that around half of the iron could be substituted for aluminium in the barium

  13. Influence of milling conditions on the wear resistance of mechanically alloyed aluminium

    Microsoft Academic Search

    María-Dolores Bermúdez; Francisco J. Carrión; Patricia Iglesias; Ginés Martínez-Nicolás; Enrique J. Herrera; José A. Rodríguez

    2005-01-01

    The tribological behaviour of mechanically alloyed (MA) aluminium-base materials has been studied as a function of processing conditions. [MA Al–NH3], milled under an ammonia atmosphere in the presence of 3.0wt.% of ethylene-bisstearamide as process control agent (PCA) and consolidated by a single cycle of cold compaction and sintering, is compared with two MA aluminium materials ([MA Al–air 1.5] and [MA

  14. Transmission Electron Microscopic Study on the ``K-State'' in Iron-Aluminium Alloys

    Microsoft Academic Search

    Denjiro Watanabe; Hiroaki Morita; Hideo Saito; Shiro Ogawa

    1970-01-01

    Transmission electron microscopy and diffraction study and electrical resistivity measurement of iron-aluminium alloys containing 17.87 to 21.54 at.% aluminium have revealed the nature of the ``K-state'' in this alloy system. It has been conclusively demonstrated by the observations of dark field images that the so-called ``K-state'', which appears on annealing at a low temperature after quenching from a high temperature,

  15. In-situ deformation of aluminium alloy polycrystals observed by high-voltage electron microscopy

    Microsoft Academic Search

    J. M. Robinson

    1995-01-01

    In-situ deformation of aluminium alloy polycrystals has been investigated within a high-voltage transmission electron microscope in order to observe dislocation phenomena related to the Portevin?Le Chatelier effect. The alloys examined are commercially pure aluminium, binary Al?2 at.% Ag, Al?2 at.% Zn, Al?2 at.% Mg and a commercial alloy containing approximately 5 at.% Mg. All the materials tested exhibit flow-stress discontinuities

  16. Design characteristics of an aluminium-air battery with consumable wedge anodes

    Microsoft Academic Search

    A. R. Despi?

    1985-01-01

    An attempt was made to optimize a mechanically rechargeable bipolar-cell battery, exemplified by an aluminium-air battery with self-perpetuating wedge anodes. The optimization involved current density of battery operation and some design parameters such as the anode thickness and the cell dimensions. It was shown that these parameters depend on the energy-to-power ratio selected by the user. The saline electrolyte aluminium-air

  17. Investigations of a large-capacity medium-power saline aluminium-air battery

    Microsoft Academic Search

    E. Budevski; I. Iliev; A. Kaisheva; A. Despi?; K. Krsmanovi?

    1989-01-01

    This paper describes the development and operation of a medium-power (24 W) aluminium-air battery with saline electrolyte or sea water. The battery consisted of two packs of 10 cells, each connected in series with a projected aluminium anode capacity of 2590 Ah. The anodes were made of a Ga-Sn-Mg alloy capable of giving 89% material efficiency, with an open circuit

  18. Roles of organic acid anion secretion in aluminium tolerance of higher plants.

    PubMed

    Yang, Lin-Tong; Qi, Yi-Ping; Jiang, Huan-Xin; Chen, Li-Song

    2013-01-01

    Approximately 30% of the world's total land area and over 50% of the world's potential arable lands are acidic. Furthermore, the acidity of the soils is gradually increasing as a result of the environmental problems including some farming practices and acid rain. At mildly acidic or neutral soils, aluminium (Al) occurs primarily as insoluble deposits and is essentially biologically inactive. However, in many acidic soils throughout the tropics and subtropics, Al toxicity is a major factor limiting crop productivity. The Al-induced secretion of organic acid (OA) anions, mainly citrate, oxalate, and malate, from roots is the best documented mechanism of Al tolerance in higher plants. Increasing evidence shows that the Al-induced secretion of OA anions may be related to the following several factors, including (a) anion channels or transporters, (b) internal concentrations of OA anions in plant tissues, (d) temperature, (e) root plasma membrane (PM) H(+)-ATPase, (f) magnesium (Mg), and (e) phosphorus (P). Genetically modified plants and cells with higher Al tolerance by overexpressing genes for the secretion and the biosynthesis of OA anions have been obtained. In addition, some aspects needed to be further studied are also discussed. PMID:23509687

  19. Comparison of electrodeposited and sputtered intrinsic and aluminium-doped zinc oxide thin films

    NASA Astrophysics Data System (ADS)

    Wellings, J. S.; Samantilleke, A. P.; Warren, P.; Heavens, S. N.; Dharmadasa, I. M.

    2008-12-01

    Intrinsic zinc oxide (i-ZnO) and aluminium-doped ZnO (ZnO:Al) are components of high-efficiency copper indium gallium diselenide solar cells. This paper examines both of these materials grown by two different techniques, namely radio frequency sputtering and electrodeposition (ED) for comparison and a better understanding. X-ray diffraction showed all materials to be polycrystalline and hexagonal (wurtzite) ZnO. Scanning electron microscopy indicated crystallites with different orientations for ED materials compared to agglomerated nanocrystallites of the sputtered layers. The band-gap energy was determined to be in the range 3.27-3.45 eV. The transmission was 85% for both ED materials and 95% for the sputtered layers. Glass/FTO/i-ZnO/Al structures were rectifying, and glass/FTO/ZnO:Al/Al contacts were ohmic for both ZnO:Al layers. Addition of Al decreases the bulk resistivity for both i-ZnO layers by 1-2 orders of magnitude. The photovoltage response to pulsed illumination showed a slow relaxation hysteresis, and all materials showed n-type electrical conduction.

  20. Investigation on Tool Wear Rate for Modified and Unmodified Aluminium-Silicon Casting Alloy

    NASA Astrophysics Data System (ADS)

    Haque, M. M.; Khan, A. A.; Ismail, Ahmad F.

    This study demonstrates and explains the effect of strontium modification on machinability of aluminium-silicon eutectic (LM-6 type) alloy. This alloy is known to have many favourable features including weight to strength ratio, high corrosion resistance and excellent castability. However, normal unmodified LM-6 alloy has poor machinability, which reduces its applications range. In this work, various samples of LM-6 alloy were cast using sand and metallic chill mould with and without strontium addition. Machining on each cast product, was carried out using recommended cutting parameters for Al-Si alloys. Strontium modified samples have recorded a reduction in average flank wear, an increase in shear plane angles and a reduction in chip thickness. The main reason for this improvement is the refining effect of strontium, which reduces the size of the hard silicon particles. As a result, their abrasive action on the tool face has reduced a lot. Dramatic reductions in tool wear rate were recorded when the microstructures were refined. On the other hand, when no refinement of microstructure occurs, tool wear rate becomes high. Chip analysis showed that strontium modified sample produced a thinner chip thickness with a larger shear plane angle, requiring less cutting forces. The tool wear depends not only on the phases present in the work material, but also on their sizes and distribution over entire structure. Thus, strontium modification has better effect on machinability of die cast alloy compared to that of the sand cast LM-6 alloy.

  1. Ruthenium complexation in an aluminium metal-organic framework and its application in alcohol oxidation catalysis.

    PubMed

    Carson, Fabian; Agrawal, Santosh; Gustafsson, Mikaela; Bartoszewicz, Agnieszka; Moraga, Francisca; Zou, Xiaodong; Martín-Matute, Belén

    2012-11-26

    A ruthenium trichloride complex has been loaded into an aluminium metal-organic framework (MOF), MOF-253, by post-synthetic modification to give MOF-253-Ru. MOF-253 contains open bipyridine sites that are available to bind with the ruthenium complex. MOF-253-Ru was characterised by elemental analysis, N(2) sorption and X-ray powder diffraction. This is the first time that a Ru complex has been coordinated to a MOF through post-synthetic modification and used as a heterogeneous catalyst. MOF-253-Ru catalysed the oxidation of primary and secondary alcohols, including allylic alcohols, with PhI(OAc)(2) as the oxidant under very mild reaction conditions (ambient temperature to 40 °C). High conversions (up to >99%) were achieved in short reaction times (1-3 h) by using low catalyst loadings (0.5 mol% Ru). In addition, high selectivities (>90%) for aldehydes were obtained at room temperature. MOF-253-Ru can be recycled up to six times with only a moderate decrease in substrate conversion. PMID:23042715

  2. Modulation of (14) C-labeled glucose metabolism by zinc during aluminium induced neurodegeneration.

    PubMed

    Singla, Neha; Dhawan, D K

    2015-09-01

    Aluminium (Al) is one of the most prominent metals in the environment and is responsible for causing several neurological disorders, including Alzheimer's disease. On the other hand, zinc (Zn) is an essential micronutrient that is involved in regulating brain development and function. The present study investigates the protective potential of Zn in the uptake of (14) C-labeled amino acids and glucose and their turnover in rat brain slices during Al intoxication. Male Sprague Dawley rats (140-160 g) were divided into four different groups: normal control, Al treated (100 mg/kg body weight/day via oral gavage), Zn treated (227 mg/liter in drinking water), and Al?+?Zn treated. Radiorespirometric assay revealed an increase in glucose turnover after Al exposure that was attenuated after Zn treatment. Furthermore, the uptake of (14) C-labeled glucose was increased after Al treatment but was appreciably decreased upon Zn supplementation. In addition, the uptakes of (14) C-lysine, (14) C-leucine, and (14) C-aspartic acid were also found to be elevated following Al exposure but were decreased after Zn treatment. Al treatment also caused alterations in the neurohistoarchitecture of the brain, which were improved after Zn coadministration. Therefore, the present study suggests that Zn provides protection against Al-induced neurotoxicity by regulating glucose and amino acid uptake in rats, indicating that Zn could be a potential candidate for the treatment of various neurodegenerative disorders. © 2015 Wiley Periodicals, Inc. PMID:25908409

  3. Galvanic corrosion behaviour of aluminium 3004 and copper in tropical marine atmosphere

    NASA Astrophysics Data System (ADS)

    Subramanian, G.; Palraj, S.; Palanichamy, S.

    2014-06-01

    The galvanic corrosion behaviour of aluminium 3004 and copper with different area ratios were studied in the tropical marine atmosphere at Tuticorin harbour over a period of 426 days. The area ratios of A Al: A Cu, studied were 1:1, 1:2, 1:4, 1:8, 2:1, 4:1 & 8:1. The galvanic corrosion behaviour of metals was studied in terms of relative increase in the corrosion rate of aluminium due to galvanic coupling with copper, relative decrease in the corrosion rate of copper due to galvanic coupling with aluminium, and the susceptibility of aluminium to pitting owing to galvanic coupling with copper. The galvanic potential and galvanic current of the system were monitored. Pits of different dimensions ranging from mild etchings to perforations were experienced on the borders and the surfaces of the interface of aluminium in contact with copper. The weathering parameters and the environmental pollutants which have a major role in influencing the galvanic corrosion of metals were also monitored. The corrosion products resulting from galvanic corrosion were analysed using XRD and the pitting on aluminium resulting from galvanic corrosion has been highlighted in terms of pit depth, size and density of pit, using a high resolution microscope.

  4. Damage of Aluminium Matrix Composite reinforced with Iron Oxide (Fe3O4): Experimental and Numerical Study

    NASA Astrophysics Data System (ADS)

    Ayari, F.; Katundi, D.; Bayraktar, E.

    2011-01-01

    The powder metallurgy components are being widely used for sophisticated industrial applications at a very high rate production and low cost. In modern industry, more and more it is imposed to develop new composites, such as high resistant, low density, alternative materials in order to realise multifunctional pieces. For this reason, it is very striking to use reinforced (Fe3O4-iron oxide) aluminium matrix composites in structural applications (automotive, aeronautical, etc.) due to their outstanding stiffness-to-weight and strength-to-weight ratios. These materials show good thermal conductivity and wear resistance and also low thermal expansion, all of which makes them very high multifunctional light weight materials. Additionally, it is very attractive way to add Fe3O4-iron oxide reinforcing for improving the magnetic permeability of this composites and by this way, it can be obtained a good synchronization between thermal and electrical conductivities and magnetic permeability.

  5. Effect of aluminium toxicity on growth responses and antioxidant activities in Gmelina arborea Roxb. inoculated with AM fungi.

    PubMed

    Dudhane, Mayura; Borde, Mahesh; Jite, Paramjit Kaur

    2012-08-01

    Arbuscular mycorrhizal fungi alleviating the adverse Aluminium effects on growth and antioxidant activity was tested in Gmelina plants. Under greenhouse and aluminium stress condition, the mycorrhizal Gmelina plants showed good growth as compared to non mycorrhizal Gmelina plants. Mycorrhizal colonization in Gmelina was found not to be significantly influenced by aluminium concentrations. Results also indicate that symbiotic association was successfully established between Glomus intraradices and Gmelina plants and mycorrhizal colonization consequently increased the biomass of Gmelina. The root proline accumulation was found to increase in mycorrhizal Gmelina plants for osmotic adjustment of stress tissues under first and second level of Aluminium stress. It was observed that Mycorrhizal colonization increased the shoot root Peroxidase and Superoxide dismutase activities in mycorrhizal Gmelina under second level of Aluminium stress. Mycorrhizal fungi play a major role in phytostabilization by secreting one of the glycoprotein, i.e., Glomalin, which stabilizes the Aluminium in soil as well as in the roots of Gmelina plants. PMID:22908633

  6. The influence of aluminium content to the stacking fault energy in Fe-Mn-Al-C alloy system

    Microsoft Academic Search

    W. S. Yang; C. M. Wan

    1990-01-01

    Four Fe-30Mn-0.9C-XAl alloys are employed to investigate the influence of aluminium content to the stacking fault energy in Fe-Mn-Al-C alloy system. The range of aluminium content is zero to 8.47 wt%. Based on the thermodynamic model, the stacking fault energy can be obtained through calculation. Increasing the aluminium content will make the stacking fault energy of Fe-30Mn-0.9C based alloys increase

  7. Properties of Aluminium Thin Films on Polyethylene Terephthalate Substrates as Back Contacts in Thin Film Silicon Solar Cells

    Microsoft Academic Search

    M. Z. Pakhuruddin; K. Ibrahim; A. Abdul Aziz

    2012-01-01

    Aluminium thin films on polyethylene terephthalate substrates prepared via thermal evaporation method and annealed under different temperatures have been investigated. High peak belongs to aluminium atoms is evident from energy dispersive X-ray spectra. From X-ray diffraction pattern, polycrystalline nature of aluminium thin film is observed with (200) dominant peak at 2? = 44.52°. With increased annealing temperatures, atomic force microscope shows increased

  8. Friction stir welding of titanium alloy TiAl6V4 to aluminium alloy AA2024-T3

    Microsoft Academic Search

    Ulrike Dressler; Gerhard Biallas; Ulises Alfaro Mercado

    2009-01-01

    Titanium alloy TiAl6V4 and aluminium alloy 2024-T3 were successfully joined by friction stir welding. Microstructure, hardness and tensile strength of the butt joint were investigated. The weld nugget exhibits a mixture of fine recrystallized grains of aluminium alloy and titanium particles. Hardness profile reveals a sharp decrease at titanium\\/aluminium interface and evidence of microstructural changes due to welding on the

  9. Cu(II), Co(II) and Ni(II) complexes of –Br and –OCH 2 CH 3 substituted Schiff bases as corrosion inhibitors for aluminium in acidic media

    Microsoft Academic Search

    A. Aytaç

    2010-01-01

    A group of Cu(II), Ni(II) and Co(II) complexes of –Br and –OCH2CH3 substituted Schiff bases as a new class of corrosion inhibitors for aluminium has been studied in 0.1 M HCl by the addition\\u000a of 10 ppm compound using potentiodynamic polarization, electrochemical impedance spectroscopy, linear polarization methods\\u000a and gas evolution tests at 25 °C. The inhibition efficiencies obtained from all methods employed are

  10. Determination of aluminium induced metabolic changes in mice liver: A Fourier transform infrared spectroscopy study

    NASA Astrophysics Data System (ADS)

    Sivakumar, S.; Sivasubramanian, J.; Khatiwada, Chandra Prasad; Manivannan, J.; Raja, B.

    2013-06-01

    In this study, we made a new approach to evaluate aluminium induced metabolic changes in liver tissue of mice using Fourier transform infrared spectroscopy analysis taking one step further in correlation with strong biochemical evidence. This finding reveals the alterations on the major biochemical constituents, such as lipids, proteins, nucleic acids and glycogen of the liver tissues of mice. The peak area value of amide A significantly decrease from 288.278 ± 3.121 to 189.872 ± 2.012 between control and aluminium treated liver tissue respectively. Amide I and amide II peak area value also decrease from 40.749 ± 2.052 to 21.170 ± 1.311 and 13.167 ± 1.441 to 8.953 ± 0.548 in aluminium treated liver tissue respectively. This result suggests an alteration in the protein profile. The absence of olefinicdbnd CH stretching band and Cdbnd O stretching of triglycerides in aluminium treated liver suggests an altered lipid levels due to aluminium exposure. Significant shift in the peak position of glycogen may be the interruption of aluminium in the calcium metabolism and the reduced level of calcium. The overall findings exhibit that the liver metabolic program is altered through increasing the structural modification in proteins, triglycerides and quantitative alteration in proteins, lipids, and glycogen. All the above mentioned modifications were protected in desferrioxamine treated mice. Histopathological results also revealed impairment of aluminium induced alterations in liver tissue. The results of the FTIR study were found to be in agreement with biochemical studies and which demonstrate FTIR can be used successfully to indicate the molecular level changes.

  11. Simulation de la formabilite des alliages d'aluminium AA5754 et AA6063

    NASA Astrophysics Data System (ADS)

    Eljaafari, Samira

    Les besoins de reduction du poids se sont concretement traduits par l'introduction de nouvelles nuances plus legeres dans les structures automobiles. Ainsi, des alliages d'aluminium ont commence a etre integres dans les pieces de structure de plusieurs vehicules. La faible masse volumique des alliages d'aluminium (2,7g/cm3) permet d'alleger le poids du vehicule qui entraine une diminution de la consommation de carburant et, donc, des emissions de gaz a effet de serre. La striction et la rupture sont les principaux modes de defaillance qui entrainent le rebut systematique des pieces. C'est pourquoi, ameliorer la prediction d'apparition de ces defauts lors de la simulation va dans le sens d'une meilleure maitrise du procede. Dans le cadre de ce travail doctoral, deux modeles sont developpes pour simuler le comportement a grandes deformations d'alliages d'aluminium: un modele polycristallin de type Taylor et un modele a un ou plusieurs elements finis par grain. Les diagrammes limites de formage (DLF) pour les deux alliages d'aluminium AA5754 et AA6063 ont ete simules numeriquement en utilisant une formulation par elements finis pour les polycristaux basee sur l'hypothese de Taylor. Les DLF conventionnels et de l'hydroformage ont ete traces. L'effet des chemins de deformation sur la formabilite des alliages d'aluminium a aussi ete etudie. Finalement, des simulations numeriques avec les donnees de diffraction des electrons retrodiffuses (EBSD) pour 1'alliage d'aluminium AA5754 ont ete effectuees en utilisant le modele a un ou plusieurs elements par grain. Ces simulations sont executees avec differents modeles du durcissement (Asaro, Bassani et puissance). Mots-cles: Formabilite; Alliage d'aluminium; Hydroformage; Glissement cristallographique; Durcissement; Calcul parallele; Diagramme limite de formage (DLF); Diffraction electron.

  12. The crucial role of mitochondrial regulation in adaptive aluminium resistance in Rhodotorula glutinis.

    PubMed

    Tani, Akio; Inoue, Chiemi; Tanaka, Yoko; Yamamoto, Yoko; Kondo, Hideki; Hiradate, Syuntaro; Kimbara, Kazuhide; Kawai, Fusako

    2008-11-01

    Rhodotorula glutinis IFO1125 was found to acquire increased aluminium (Al) resistance from 50 microM to more than 5 mM by repetitive culturing with stepwise increases in Al concentration at pH 4.0. To investigate the mechanism underlying this novel phenomenon, wild-type and Al-resistant cells were compared. Neither cell type accumulated the free form of Al (Al(3+)) added to the medium. Transmission electron microscopic analyses revealed a greater number of mitochondria in resistant cells. The formation of small mitochondria with simplified cristae structures was observed in the wild-type strain grown in the presence of Al and in resistant cells grown in the absence of Al. Addition of Al to cells resulted in high mitochondrial membrane potential and concomitant generation of reactive oxygen species (ROS). Exposure to Al also resulted in elevated levels of oxidized proteins and oxidized lipids. Addition of the antioxidants alpha-tocopherol and ascorbic acid alleviated the Al toxicity, suggesting that ROS generation is the main cause of Al toxicity. Differential display analysis indicated upregulation of mitochondrial genes in the resistant cells. Resistant cells were found to have 2.5- to 3-fold more mitochondrial DNA (mtDNA) than the wild-type strain. Analysis of tricarboxylic acid cycle and respiratory-chain enzyme activities in wild-type and resistant cells revealed significantly reduced cytochrome c oxidase activity and resultant high ROS production in the latter cells. Taken together, these data suggest that the adaptive increased resistance to Al stress in resistant cells resulted from an increased number of mitochondria and increased mtDNA content, as a compensatory response to reduced respiratory activity caused by a deficiency in complex IV function. PMID:18957597

  13. Aluminium impact on freshwater invertebrates at low pH: A review

    NASA Astrophysics Data System (ADS)

    Herrmann, Jan

    The state of knowledge on aluminium (Al) impact on freshwater invertebrates at low pH is reviewed. Mainly inorganic ions seem to be biologically harmful. Published effect/mechanism descriptions may seem somewhat contradictory, but this can be due to the heterogeneity of "the invertebrate group", as well as the multitude and complexity of occurring Al species, thereby also Al analysis problems. Addition of Al to streams has in some cases increased drift and death of mainly some "surface-dependent" species (chironomids, mayflies, dance flies, dixid midges), but also some strictly benthic animals (isopods, stoneflies), while other studies on a variety of animals do not record any change in neither drift, mortality nor biomass. In laboratory exposures Al has been shown to cause raised mortality for some daphnids and blackfly larvae at pH around 5; in the latter animals the effect was however mitigated by humus. A variety of other freshwater invertebrates were not affected. Moreover, at pH 4, Al has even been shown to improve the survival of mayfly nymphs and daphnids, otherwise impaired by the low pH in itself. The reason for this is not clear. Proofs for "food chain accumulation" of Al are still weak. Very high additions of Al have caused a decreased respiration rate in a dragonfly nymph, while a more field-relevant exposure level increased respiration in mayfly nymphs. This suggests a stress situation, probably due to impaired osmoregulation, indicating chemical or mechanical Al impact. The lowered oxygen uptake is then compensated for by improved respiration rate. A model for this is presented. Studies on crayfish, daphnids, mayflies and waterbugs indicate that Al can lower osmoregulatory efficiency and thereby affect the ion balance maintaining mechanisms of the animals. Such sublethal effects are important and should be studied further. The review also critically discusses the concepts mortality and bioavailability.

  14. Going Loopy for Addition

    NSDL National Science Digital Library

    Tracey DeCloedt

    2012-07-30

    The students will partner up and use Fruit Loops to represent addition equations up to a sum of 10. They will draw, act out, use verbal explanations and write equations to show their addition equations.

  15. Outcome of erbium:yttrium aluminium garnet laser resurfacing treatments.

    PubMed

    Cole, R P; Widdowson, D; Moore, J C

    2008-10-01

    Erbium:yttrium aluminium garnet (erbium:YAG) laser treatment was used to resurface skin abnormalities in patients suffering from conditions that included epidermal naevi, tuberous sclerosis, angiofibromata, neurofibromatosis, and scarring caused by acne or other means. Patients completed self-report questionnaires before their first laser test patch session, and again approximately 4 months after one treatment, so that its success could be evaluated from the patient's perspective. Disability and distress were quantified with the University of York Health Measurement Questionnaire (HMQ). Satisfaction with appearance was measured with a specifically designed Salisbury Appearance Scale (SAS) questionnaire. Pretreatment questionnaires were completed by 108 (HMQ) and 80 (SAS) patients. Thirty-six (HMQ) and 22 (SAS) patients completed a full treatment during the study period. Some patients had a test patch only during the study period. Others decided against further treatment after the test patch. Control SAS questionnaires were completed by 29 subjects on two occasions and showed no change over time. There was a significant improvement in patient satisfaction with appearance (SAS), but there was no significant difference in the disability and distress (HMQ) after erbium:YAG resurfacing. PMID:18074165

  16. Speciation of aluminium, arsenic and molybdenum in excessively limed lakes.

    PubMed

    Sjöstedt, Carin; Wällstedt, Teresia; Gustafsson, Jon Petter; Borg, Hans

    2009-09-01

    The possible existence of the potentially toxic oxyanions of Al (Al(OH)(4)(-)), As (HAsO(4)(2-)), and Mo (MoO(4)(2-)) was examined in excessively limed lakes. In-situ dialysis (MWCO 1 kDa) was performed in the surface and bottom waters of two excessively limed lakes (pH 7.1-7.7) and one acidic lake (pH approximately 5.4). The dialysable metal concentrations were compared to the equilibrium distribution of species as calculated with the geochemical code Visual MINTEQ incorporating the CD-MUSIC and Stockholm Humic models for complexation onto colloidal ferrihydrite and dissolved organic matter. Arsenic and molybdenum in the excessively limed lakes were to a large extent present in the dialysable fraction (>79% and >92% respectively). They were calculated to exist as free or adsorbed oxyanions. Most of the Al was observed to reside in the colloidal fraction (51-82%). In agreement with this, model predictions indicated aluminium to be present mostly as colloids or bound to dissolved organic matter. Only a small fraction was modelled as Al(OH)(4)(-) ions. In most cases, modelled values were in agreement with the dialysis results. The free concentrations of the three oxyanions were mostly low compared to toxic levels. PMID:19540566

  17. Aluminium exposure disrupts elemental homeostasis in Caenorhabditis elegans†

    PubMed Central

    Page, Kathryn E.; White, Keith N.; McCrohan, Catherine R.

    2013-01-01

    Aluminium (Al) is highly abundant in the environment and can elicit a variety of toxic responses in biological systems. Here we characterize the effects of Al on Caenorhabditis elegans by identifying phenotypic abnormalities and disruption in whole-body metal homeostasis (metallostasis) following Al exposure in food. Widespread changes to the elemental content of adult nematodes were observed when chronically exposed to Al from the first larval stage (L1). Specifically, we saw increased barium, chromium, copper and iron content, and a reduction in calcium levels. Lifespan was decreased in worms exposed to low levels of Al, but unexpectedly increased when the Al concentration reached higher levels (4.8 mM). This bi-phasic phenotype was only observed when Al exposure occurred during development, as lifespan was unaffected by Al exposure during adulthood. Lower levels of Al slowed C. elegans developmental progression, and reduced hermaphrodite self-fertility and adult body size. Significant developmental delay was observed even when Al exposure was restricted to embryogenesis. Similar changes in Al have been noted in association with Al toxicity in humans and other mammals, suggesting that C. elegans may be of use as a model for understanding the mechanisms of Al toxicity in mammalian systems. PMID:22534883

  18. The interpretation of polycrystalline coherent inelastic neutron scattering from aluminium

    PubMed Central

    Roach, Daniel L.; Ross, D. Keith; Gale, Julian D.; Taylor, Jon W.

    2013-01-01

    A new approach to the interpretation and analysis of coherent inelastic neutron scattering from polycrystals (poly-CINS) is presented. This article describes a simulation of the one-phonon coherent inelastic scattering from a lattice model of an arbitrary crystal system. The one-phonon component is characterized by sharp features, determined, for example, by boundaries of the (Q, ?) regions where one-phonon scattering is allowed. These features may be identified with the same features apparent in the measured total coherent inelastic cross section, the other components of which (multiphonon or multiple scattering) show no sharp features. The parameters of the model can then be relaxed to improve the fit between model and experiment. This method is of particular interest where no single crystals are available. To test the approach, the poly-CINS has been measured for polycrystalline aluminium using the MARI spectrometer (ISIS), because both lattice dynamical models and measured dispersion curves are available for this material. The models used include a simple Lennard-Jones model fitted to the elastic constants of this material plus a number of embedded atom method force fields. The agreement obtained suggests that the method demonstrated should be effective in developing models for other materials where single-crystal dispersion curves are not available. PMID:24282332

  19. Involvement of ASR genes in aluminium tolerance mechanisms in rice.

    PubMed

    Arenhart, Rafael Augusto; Lima, Julio César de; Pedron, Marcelo; Carvalho, Fabricio E L; Silveira, Joaquim Albenisio Gomes da; Rosa, Silvia Barcelos; Caverzan, Andreia; Andrade, Claudia M B; Schünemann, Mariana; Margis, Rogério; Margis-Pinheiro, Márcia

    2013-01-01

    Among cereal crops, rice is considered the most tolerant to aluminium (Al). However, variability among rice genotypes leads to remarkable differences in the degree of Al tolerance for distinct cultivars. A number of studies have demonstrated that rice plants achieve Al tolerance through an unknown mechanism that is independent of root tip Al exclusion. We have analysed expression changes of the rice ASR gene family as a function of Al treatment. The gene ASR5 was differentially regulated in the Al-tolerant rice ssp. Japonica cv. Nipponbare. However, ASR5 expression did not respond to Al exposure in Indica cv. Taim rice roots, which are highly Al sensitive. Transgenic plants carrying RNAi constructs that targeted the ASR genes were obtained, and increased Al susceptibility was observed in T1 plants. Embryogenic calli of transgenic rice carrying an ASR5-green fluorescent protein fusion revealed that ASR5 was localized in both the nucleus and cytoplasm. Using a proteomic approach to compare non-transformed and ASR-RNAi plants, a total of 41 proteins with contrasting expression patterns were identified. We suggest that the ASR5 protein acts as a transcription factor to regulate the expression of different genes that collectively protect rice cells from Al-induced stress responses. PMID:22676236

  20. Electrocoagulation efficiency of the tannery effluent treatment using aluminium electrodes.

    PubMed

    Espinoza-Quiñones, Fernando R; Fornari, Marilda M T; Módenes, Aparecido N; Palácio, Soraya M; Trigueros, Daniela E G; Borba, Fernando H; Kroumov, Alexander D

    2009-01-01

    An electro-coagulation laboratory scale system using aluminium plates electrodes was studied for the removal of organic and inorganic pollutants as a by-product from leather finishing industrial process. A fractional factorial 2(3) experimental design was applied in order to obtain optimal values of the system state variables. The electro-coagulation (EC) process efficiency was based on the chemical oxygen demand (COD), turbidity, total suspended solid, total fixed solid, total volatile solid, and chemical element concentration values. Analysis of variance (ANOVA) for final pH, total fixed solid (TFS), turbidity and Ca concentration have confirmed the predicted models by the experimental design within a 95% confidence level. The reactor working conditions close to real effluent pH (7.6) and electrolysis time in the range 30-45 min were enough to achieve the cost effective reduction factors of organic and inorganic pollutants' concentrations. An appreciable improvement in COD removal efficiency was obtained for electro-coagulation treatment. Finally, the technical-economical analysis results have clearly shown that the electro-coagulation method is very promising for industrial application. PMID:19844065

  1. Aspects of fabrication aluminium matrix heterophase composites by suspension method

    NASA Astrophysics Data System (ADS)

    Dolata, A. J.; Dyzia, M.

    2012-05-01

    Composites with an aluminium alloy matrix (AlMMC) exhibit several advantageous properties such as good strength, stiffness, low density, resistance and dimensional stability to elevated temperatures, good thermal expansion coefficient and particularly high resistance to friction wear. Therefore such composites are more and more used in modern engineering constructions. Composites reinforced with hard ceramic particles (Al2O3, SiC) are gradually being implemented into production in automotive or aircraft industries. Another application of AlMMC is in the electronics industry, where the dimensional stability and capacity to absorb and remove heat is used in radiators. However the main problems are still: a reduction of production costs, developing methods of composite material tests and final product quality assessment, standardisation, development of recycling and mechanical processing methods. AlMMC production technologies, based on liquid-phase methods, and the shaping of products by casting methods, belong to the cheapest production methods. Application of a suspension method for the production of composites with heterophase reinforcement may turn out to be a new material and technological solution. The article presents the material and technological aspects of the transfer procedures for the production of composite suspensions from laboratory scale to a semi-industrial scale.

  2. Pulmonary Fibrosis and Encephalopathy Associated with the Inhalation of Aluminium Dust

    PubMed Central

    McLaughlin, A. I. G.; Kazantzis, G.; King, E.; Teare, Donald; Porter, R. J.; Owen, R.

    1962-01-01

    The clinical, radiographic, pathological, and environmental features of a case of extensive aluminium fibrosis of the lungs are reported in a man of 49 years of age who had worked for 13½ years in the ball-mill room of an aluminium powder factory. It is noteworthy that his symptoms were referable to the central nervous system, and that he died from terminal broncho-pneumonia following rapidly progressive encephalopathy, associated with epileptiform attacks. He had no presenting pulmonary symptoms, and ?-ray examination of the chest showed only slight abnormalities. Radiographic examination of the chests of 53 other workers in the same factory, and clinical examination with lung function tests of 23 of them revealed no other definite cases of aluminium fibrosis of the lung, nor any other cases with neurological signs and symptoms. Estimations of the aluminium contents of the body tissues such as the lungs, brain, liver, and bone are also recorded. When compared with normal values, it was found that the lungs and brain contained about 20 times and the liver 122 times more than normal. As a contribution to the study of the aluminium content of normal tissues, and as a control series for the results given by Tipton, Cook, Steiner, Foland, McDaniel, and Fentress (1957), and Tipton, Cook, Foland, Rittner, Hardwick, and McDaniel (1958, 1959), the aluminium content of eight “normal” brains was estimated and in all cases it was found to be less than 0·6 ?g. Al/g. wet weight. The results of a survey of the dust concentrations in the factory are also given. The use of aluminium compounds in the experimental production of epilepsy in primates is reviewed, and it is suggested that the neurological signs and symptoms with epileptiform convulsions which occurred in this case might have been related to aluminium intoxication. We hold the view, however, that the interstitial and nodular fibrosis found in the lungs was undoubtedly associated with the inhalation and retention of aluminium dust. Images PMID:13932137

  3. Highly aluminium doped barium and strontium ferrite nanoparticles prepared by citrate auto-combustion synthesis

    SciTech Connect

    Shirtcliffe, Neil J. [Nottingham Trent University, Clifton Lane, Clifton, Nottingham NG11 8NS (United Kingdom)]. E-mail: neil.shirtcliffe@ntu.ac.uk; Thompson, Simon [Nottingham Trent University, Clifton Lane, Clifton, Nottingham NG11 8NS (United Kingdom); O'Keefe, Eoin S. [QinetiQ, Farnborough, Hampshire (United Kingdom); Appleton, Steve [QinetiQ, Farnborough, Hampshire (United Kingdom); Perry, Carole C. [Nottingham Trent University, Clifton Lane, Clifton, Nottingham NG11 8NS (United Kingdom)]. E-mail: carole.perry@ntu.ac.uk

    2007-02-15

    Aluminium doped barium and strontium hexaferrite nanoparticles BaAl {sub x}Fe{sub (12-x)}O{sub 19} and SrAl {sub x}Fe{sub (12-x)}O{sub 19} were synthesised via a sol-gel route using citric acid to complex the ions followed by an auto-combustion reaction. This method shows promise for the synthesis of complex ferrite powders with small particle size. It was found that around half of the iron could be substituted for aluminium in the barium ferrite with structure retention, whereas strontium aluminium ferrites could be produced with any aluminium content including total substitution of the iron. All synthesised materials consisted of particles smaller than 1 {mu}m, which is the size of a single magnetic domain, and various doping levels were achieved with the final elemental composition being within the bounds of experimental error. The materials show structural and morphological changes as they move from iron to aluminium ferrites. Such materials may be promising for imaging applications.

  4. Effect of atomic parameters on determination of aluminium abundance in atmospheres of late-type stars

    NASA Astrophysics Data System (ADS)

    Menzhevitski, V. S.; Shimanskaya, N. N.; Shimansky, V. V.; Kudryavtsev, D. O.

    2014-04-01

    We study the effect of the photoionization cross sections for the ground state of Al I on the inferred aluminium abundance in stellar atmospheres. We match the theoretical and observed line profiles of the resonance ?? 3944.01, 3961.52 Å and subordinate ?? 6696.03, 6698.68 Å doublets in high-resolution spectra of the metal-poor solar-type stars HD22879 and HD201889. We determine the parameters of these stars from their photometric and spectroscopic data. Our computations show that the profiles can be matched and a single aluminium abundance inferred simultaneously from both groups of spectral lines only with low photoionization cross sections (about 10-12 Mb). Larger cross sections (about 58-65 Mb) make such fits impossible. We therefore conclude that small photoionization cross sections should be preferred for the determination of aluminium abundances in metal-poor stars. We redetermine the aluminium abundances in the atmospheres of halo stars. The resulting abundances prove to be lower by 0.1-0.15 dex than our earlier determinations which does not affect the conclusions based on our earlier estimates. In particular, the NLTE [Al/Fe]-[Fe/H] dependence, on the whole, agrees only qualitatively with the results of theoretical predictions. Therefore further refinement of the theory of nuclear synthesis of aluminium in the process of the chemical evolution of the Galaxy remains a task of current importance.

  5. The recycling of metals by plastic deformation: an example of recycling of aluminium and its alloys chips

    Microsoft Academic Search

    J Gronostajski; A Matuszak

    1999-01-01

    In this paper a new method of recycling aluminium and aluminium-alloy chips coming from the machining of semi-finished products, which are very difficult to recycle by conventional methods, is presented. The method consists in the conversion of the chips directly (without melting processes) into a finished product. Using a powder metallurgy technique followed by extrusion, the method has been applied

  6. Further studies of the anodic dissolution in sodium chloride electrolyte of aluminium alloys containing tin and gallium

    Microsoft Academic Search

    Maria Nestoridi; Derek Pletcher; Julian A. Wharton; Robert J. K. Wood

    2009-01-01

    As part of a programme to develop a high power density, Al\\/air battery with a NaCl brine electrolyte, the high rate dissolution of an aluminium alloy containing tin and gallium was investigated in a small volume cell. The objective was to define the factors that limit aluminium dissolution in condition that mimic a high power density battery. In a cell

  7. Assessing aluminium toxicity in streams affected by acid mine drainage.

    PubMed

    Waters, A S; Webster-Brown, J G

    2013-01-01

    Acid mine drainage (AMD) has degraded water quality and ecology in streams on the Stockton Plateau, the site of New Zealand's largest open-cast coal mining operation. This has previously been attributed largely to the effects of acidity and elevated aluminium (Al) concentrations. However, the toxicity of dissolved Al is dependent on speciation, which is influenced by pH which affects Al hydrolysis, as well as the concentrations of organic carbon and sulphate which complex Al. Methods for the assessment of the toxic fraction of Al, by chemical analysis and geochemical modelling, have been investigated in selected streams on the Stockton Plateau, where dissolved Al concentrations ranged from 0.034 to 27 mg L(-1). Modelling using PHREEQC indicated that between 0.2 and 85% of the dissolved Al was present as the free ion Al(3+), the most toxic Al species, which dominated in waters of pH = 3.8-4.8. Al-sulphate complexation reduced the Al(3+) concentration at lower pH, while Al-organic and -hydroxide complexes dominated at higher pH. Macroinvertebrate richness in the streams identified an Al(3+) 'threshold' of approximately 0.42 mg/L, above which taxa declined rapidly. Colorimetric 'Aluminon' analysis on unpreserved, unfiltered waters provided a better estimation of Al(3+) concentrations than inductively couple plasma-mass spectrometry (ICP-MS) on filtered, acidified waters. The Aluminon method does not react with particulate Al or strong Al complexes, often registering as little as 53% of the dissolved Al concentration determined by ICP-MS. PMID:23579831

  8. Aluminum Economy for Sustainable Development: Aluminium as Core Material for Energy Storage and Energy Saving Products: Low Cost, High Performance, and Easy Processing in Developing Countries

    Microsoft Academic Search

    S. C. Mok

    2011-01-01

    The ¡§Aluminium Economy¡¨ is put forward as an attractive basis for an energy efficient community. As energy storage medium, aluminium batteries have high specific energy density and simple, safe construction. Aluminium is also demonstrating low-cost and high performance in energy related applications such as electric cable, light weight vehicle, building material, LED heat-sink, and solar reflector. It is particularly suited

  9. A comparison of phosphorus and fluorine containing IL lubricants for steel on aluminium.

    PubMed

    Somers, Anthony E; Biddulph, Shannon M; Howlett, Patrick C; Sun, Jiazeng; MacFarlane, Douglas R; Forsyth, Maria

    2012-06-14

    Ionic liquids have been shown to be highly effective lubricants for a steel on aluminium system. This work shows that the chemistry of the anion and cation are critical in achieving maximum wear protection. The performance of the ILs containing a diphenylphosphate (DPP) anion all showed low wear, as did some of the tris(pentafluoroethyl)trifluorophosphate (FAP) and bis(trifluoromethanesulfonyl)amide (NTf(2)) anion containing ILs. However, in the case of the FAP and NTf(2) based systems, a cation dependence was observed, with relatively poor wear resistance obtained in the case of an imidazolium FAP and two pyrrolidinium NTf(2) salts, probably due to tribocorrosion caused by the fluorine reaction with the aluminium substrate. The systems exhibiting poor performance generally had a lower viscosity, which also impacts on their tribological properties. Those ILs that exhibited low wear were shown to have formed protective tribofilms on the aluminium alloy surface. PMID:22555280

  10. DFT study on the interaction between monomeric aluminium and chloride ion in aqueous solution.

    PubMed

    Jin, Xiaoyan; Yang, Wenjing; Qian, Zhaosheng; Wang, Yingjie; Bi, Shuping

    2011-05-14

    The interaction of monomeric aluminium and chloride ion in aqueous solution is investigated by density functional theory (DFT) calculations. The computational results show that it is difficult for Cl(-) to enter the inner-coordination shell of aluminium complexes by replacing the bound water molecules, independent of pH and the concentration of Cl(-). However, pH and the concentration of Cl(-) might influence the conformations, bond lengths and natural charge populations of monomeric aluminium complexes to a given extent. Based on the computed Gibbs energies, pK(a) values of various hydrolysis species in the presence and absence of Cl(-) are evaluated, respectively. It is concluded that pK(a) increases with the introduction of Cl(-). PMID:21451819

  11. Microstructure and mechanical properties of accumulative roll bonded aluminium alloy AA5754

    NASA Astrophysics Data System (ADS)

    Hausöl, T.; Höppel, H. W.; Göken, M.

    2010-07-01

    The aluminium alloy AA5754 is used for many technical applications. In this work, the accumulative roll bonding process is applied to this alloy in order to investigate the potential of an ultrafine-grained structure on the mechanical properties of this Al-Mg alloy. Sheets from AA5754 (AlMg3) were successfully processed by accumulative roll bonding in order to obtain an ultrafine-grained microstructure. The ARB process was performed at 230 °C or 250 °C up to 7 or 8 cycles respectively. Thus the grain size decreased from 10 ?m (initial state) to approximately 80 nm (ultrafine-grained state, normal direction). The microstructural evolution and the mechanical properties have been investigated by means of scanning electron microscopy, hardness measurements and tensile testing. After one ARB cycle the samples showed an increase in hardness by a factor of almost 2 in comparison to the as-received material. Further processing causes a linear increase of hardness with each additional cycle. Yield strength and tensile strength of the roll bonded specimens are highly increased in comparison to the as-received samples whereas the ductility declined. A considerable increase in ductility is obtained by heat treatment of the ARB specimens at 250 °C, but on the expense of a moderate decreased strength. The deformation behaviour is also influenced by the ultrafine-grained structure. The occurrence of the Portevin-Le Chatelier effect is manifested by serrated stress-strain curves. The amplitude of serrations increases with increasing number of ARB cycles but can be reduced by the appliance of a higher strain rate. Lüders strain only occurs at the as-received, i.e. not strained, samples.

  12. In situ observation and analysis of ultrasonic capillary effect in molten aluminium.

    PubMed

    Tzanakis, I; Xu, W W; Eskin, D G; Lee, P D; Kotsovinos, N

    2015-11-01

    An in situ synchrotron radiographic study of a molten Al-10wt% Cu alloy under the influence of an external ultrasonic field was carried out using the Diamond-Manchester Branchline pink X-ray imaging at the Diamond Light Source in UK. A bespoke test rig was used, consisting of an acoustic transducer with a titanium sonotrode coupled with a PID-controlled resistance furnace. An ultrasonic frequency of 30kHz, with a peak to peak amplitude at 140microns, was used, producing a pressure output of 16.9MPa at the radiation surface of the 1-mm diameter sonotrode. This allowed quantification of not only the cavitation bubble formation and collapse, but there was also evidence of the previously hypothesised ultrasonic capillary effect (UCE), providing the first direct observations of this phenomenon in a molten metallic alloy. This was achieved by quantifying the re-filling of a pre-existing groove in the shape of a tube (which acted as a micro-capillary channel) formed by the oxide envelope of the liquid sample. Analytical solutions of the flow suggest that the filling process, which took place in very small timescales, was related to micro-jetting from the collapsing cavitation bubbles. In addition, a secondary mechanism of liquid penetration through the groove, which is related with the density distribution of the oxides inside the groove, and practically to the filtration of aluminium melt from oxides, was revealed. The observation of the almost instantaneous re-filling of a micro-capillary channel with the metallic melt supports the hypothesised sono-capillary effect in technologically important liquids other than water, like metallic alloys with substantially higher surface tension and density. PMID:26186822

  13. Chloro-sulphur additive

    SciTech Connect

    Lenack, A.L.

    1980-10-14

    Compounds suitable as extreme pressure additives for lubricating oils are of the general formula CX3-S-S-R where X is a halogen and R is a hydrocarbyl. The performance of the compounds is improved by the addition of a stabilizer.

  14. Generalized additive mixed models

    Microsoft Academic Search

    Colin Chen

    2000-01-01

    Following the extension from linear mixed models to additive mixed models, extension from generalized linear mixed models to generalized additive mixed models is made, Algorithms are developed to compute the MLE's of the nonlinear effects and the covariance structures based on the penalized marginal likelihood. Convergence of the algorithms and selection of the smooth param¬eters are discussed.

  15. Numerical analysis of experiments on the generation of shock waves in aluminium under indirect (X-ray) action on the Iskra-5 facility

    SciTech Connect

    Bondarenko, S V; Dolgoleva, G V; Novikova, E A

    2013-07-31

    The dynamics of laser and X-ray radiation fields in experiments with cylindrical converter boxes (illuminators), which had earlier been carried out on the Iskra-5 laser facility (the second harmonic of iodine laser radiation, {lambda} = 0.66 {mu}m) was investigated in a sector approximation using the SND-LIRA numerical technique. In these experiments, the X-ray radiation temperature in the box was determined by measuring the velocity of the shock wave generated in the sample under investigation, which was located at the end of the cylindrical illuminator. Through simulations were made using the SND-LIRA code, which took into account the absorption of laser driver radiation at the box walls, the production of quasithermal radiation, as well as the formation and propagation of the shock wave in the sample under investigation. An analysis of the experiments permits determining the electron thermal flux limiter f: for f = 0.03 it is possible to match the experimental scaling data for X-ray in-box radiation temperature to the data of our simulations. The shock velocities obtained from the simulations are also consistent with experimental data. In particular, in the experiment with six laser beams (and a laser energy E{sub L} = 1380 J introduced into the box) the velocity of the shock front (determined from the position of a laser mark) after passage through a 50-{mu}m thick base aluminium layer was equal to 35{+-}1.6 km s{sup -1}, and in simulations to 36 km s{sup -1}. In the experiment with four laser beams (for E{sub L} = 850 J) the shock velocity (measured from the difference of transit times through the base aluminium layer and an additional thin aluminium platelet) was equal to 30{+-}3.6 km s{sup -1}, and in simulations to 30 km s{sup -1}. (interaction of laser radiation with matter)

  16. Analysis of cutting forces during dry turning processes of UNS A92024-T3 aluminium bars

    NASA Astrophysics Data System (ADS)

    de Agustina, B.; Rubio, E. M.

    2012-04-01

    In the aeronautical and aerospace industries there is a great demand of materials with high resistance and low weight such as the aluminium alloys for the production of different elements that conforms the airships and aerospace vehicles. In this work, an experimental study was carried out in order to analyse the influence of the cutting parameters (feed rate, cutting speed and type of tool) on the forces generated during dry turning tests of UNS A92024-T3 aluminium bars. The main influents factors on the forces were the feed rate and the interaction between type of tool and the spindle speed.

  17. The microstructures of aluminium alloy metal-matrix composites manufactured by squeeze casting

    Microsoft Academic Search

    D. L. Zhang; C. Brindley; B. Cantor

    1993-01-01

    Squeeze-cast metal-matrix composite ingots have been manufactured by recasting A356\\/10% SiCp and by melt infiltrating A357\\/Al2O3f. The resulting microstructures have been examined by optical and transmission electron microscopy. The primary aluminium in squeeze-cast A356\\/10% SiCp exhibits a dendritic structure with eutectic silicon particles and SiC particulate distributed throughout the interdendritic regions. Unlike squeeze-cast monolithic A357, the primary aluminium dendrite arm

  18. Development of anodes for aluminium\\/air batteries — solution phase inhibition of corrosion

    Microsoft Academic Search

    D. D. Macdonald; C. English

    1990-01-01

    The discharge characteristics of aluminium in inhibited and uninhibited 4 M KOH at 50°C have been explored. The performance of pure aluminium as a fuel is compared with that for two leading alloy fuels that had been evaluated in our previous work, Alloy BDW (Al-1Mg-0.1In-0.2Mn) and Alloy 21 (Al-0.2Ga-0.1In-0.1Tl). The inhibitors employed in this study, SnO32-, In(OH)3, BiO33-, Ga(OH)4-, MnO42-,

  19. Food additives and allergy.

    PubMed

    Weber, R W

    1993-03-01

    There is ample evidence that food additives of several sorts may precipitate adverse reactions. Some of these have catastrophic potential such as sulfite sensitivity in asthmatic patients. Fortunately, asthmatic responses to a variety of additives are certainly not as prevalent as once feared, and are probably unusual. Restricted diets are of no general benefit in asthmatic patients. In contrast to asthma, urticarial or other cutaneous reactions to food additives are more common. A restricted diet for a few months' duration may be beneficial, although the mechanism through which this is achieved is unclear. Suspected food additive sensitivities are best documented by oral challenges, preferably in a double-blind manner. Challenges in asthmatic patients need to be done with patients continuing on their routine medications to avoid false positives. All care should be taken to titrate the doses and schedule the doses appropriately, since several of these agents could provoke large drops in pulmonary function. With urticarial patients, an adequate baseline of urticarial activity needs to be established before the challenges so that fluctuations in normal activity are not construed as a positive result. Despite a large number of studies evaluating the role of food additives in hyperkinesis, results are not uniform. Evidence does suggest that there is a small subset of primarily younger children in whom additives will impact on behavior. As with asthma and additives, the problem appears to be much smaller than originally postulated. PMID:8452311

  20. Polyimide processing additives

    NASA Technical Reports Server (NTRS)

    Fletcher, James C. (inventor); Pratt, J. Richard (inventor); St.clair, Terry L. (inventor); Stoakley, Diane M. (inventor); Burks, Harold D. (inventor)

    1992-01-01

    A process for preparing polyimides having enhanced melt flow properties is described. The process consists of heating a mixture of a high molecular weight poly-(amic acid) or polyimide with a low molecular weight amic acid or imide additive in the range of 0.05 to 15 percent by weight of additive. The polyimide powders so obtained show improved processability, as evidenced by lower melt viscosity by capillary rheometry. Likewise, films prepared from mixtures of polymers with additives show improved processability with earlier onset of stretching by TMA.

  1. Awesome Addition Games

    NSDL National Science Digital Library

    Ms. Smith

    2010-10-14

    These games are fun to play and will test your addition skills! Click on the links to play the games! Play in the Kitten Match and test your math skills!! Pick the grade level you want to play on. Then pick numbers that add up to equal the number that they give you. Hurry, you're being timed! Use your addition skills to win a Diaper Derby!! First decide what you want your baby to look like! Then perform the addition problem that ...

  2. Polyimide processing additives

    NASA Technical Reports Server (NTRS)

    Pratt, J. Richard (inventor); St.clair, Terry L. (inventor); Stoakley, Diane M. (inventor); Burks, Harold D. (inventor)

    1993-01-01

    A process for preparing polyimides having enhanced melt flow properties is described. The process consists of heating a mixture of a high molecular weight poly-(amic acid) or polyimide with a low molecular weight amic acid or imide additive in the range of 0.05 to 15 percent by weight of the additive. The polyimide powders so obtained show improved processability, as evidenced by lower melt viscosity by capillary rheometry. Likewise, films prepared from mixtures of polymers with additives show improved processability with earlier onset of stretching by TMA.

  3. Additional Types of Neuropathy

    MedlinePLUS

    ... A A Listen En Español Additional Types of Neuropathy Charcot's Joint Charcot's Joint, also called neuropathic arthropathy, ... can stop bone destruction and aid healing. Cranial Neuropathy Cranial neuropathy affects the 12 pairs of nerves ...

  4. Experimental studies on machining characteristics of hybrid aluminium metal matrix composite and carbon nano tubes added hybrid aluminium metal matrix composite

    Microsoft Academic Search

    T. Sasimurugan; K. Palanikumar

    2011-01-01

    This paper discusses the comparative study on machining hybrid aluminium metal matrix composites (Al6061-SiC-Al2O3) and carbon nano tubes (CNT) added hybrid MMCs. The ordinary hybrid composites were fabricated using the liquid metallurgy technique by stir casting method under which wt.6% of particulates SiC and Al2O3 were dispersed in the base matrix. The second CNT-hybrid composite is a woven alumina (Al2O3)

  5. Additive Manufacturing Infrared Inspection

    NASA Technical Reports Server (NTRS)

    Gaddy, Darrell

    2014-01-01

    Additive manufacturing is a rapid prototyping technology that allows parts to be built in a series of thin layers from plastic, ceramics, and metallics. Metallic additive manufacturing is an emerging form of rapid prototyping that allows complex structures to be built using various metallic powders. Significant time and cost savings have also been observed using the metallic additive manufacturing compared with traditional techniques. Development of the metallic additive manufacturing technology has advanced significantly over the last decade, although many of the techniques to inspect parts made from these processes have not advanced significantly or have limitations. Several external geometry inspection techniques exist such as Coordinate Measurement Machines (CMM), Laser Scanners, Structured Light Scanning Systems, or even traditional calipers and gages. All of the aforementioned techniques are limited to external geometry and contours or must use a contact probe to inspect limited internal dimensions. This presentation will document the development of a process for real-time dimensional inspection technique and digital quality record of the additive manufacturing process using Infrared camera imaging and processing techniques.

  6. Comparative Study of 3D Printing Technologies for Rapid Casting of Aluminium Alloy

    Microsoft Academic Search

    Simranpreet Singh Gill; Munish Kaplas

    2009-01-01

    The purpose of this study is to compare the efficacy of two rapid casting technologies, namely, ZCast process and investment casting based on 3D printing technique of rapid prototyping for casting of aluminium alloy. A standard procedure has been premeditated starting from the identification and design of benchmark. The concept was presented in physical form by producing prototypes to assess

  7. Calcium\\/aluminium interactions in the cell wall and plasma membrane of Chara

    Microsoft Academic Search

    Robert J. Reid; Mark A. Tester; F. Andrew Smith

    1995-01-01

    The proposal that aluminium (Al) toxicity in plants is caused by either inhibition of Ca2+ influx or by displacement of Ca2+ from the cell wall, was examined. For this study the giant alga Chara corallina Klein ex Will. em. R.D. Wood was selected because it shows a similar sensitivity to Al as in roots of higher plants and, more importantly,

  8. Crashworthiness of Aluminium Tubes; Part 2: Improvement of Hydroforming Operation to Increase Absorption Energy

    Microsoft Academic Search

    Guillaume D'Amours; Ahmed Rahem; Robert Mayer; Bruce Williams; Michael Worswick

    2007-01-01

    The motivation to reduce overall vehicle weight within the automotive sector drives the substitution of lightweight materials such as aluminium alloys for structural components. Such a substitution requires a significant amount of development to manufacture structurally parts such that the energy absorption characteristics are not sacrificed in the event of crash. The effects of the manufacturing processes on the crash

  9. Retardation of crack growth in an aluminium alloy using a thermomechanical conditioning cycle

    Microsoft Academic Search

    R. N Ibrahim; R. S. D Sayers; D Ischenko

    1998-01-01

    The improvement of a material's fracture toughness has significant industrial applications. An example is the manufacture and maintenance of commercial gas containers made in the form of aluminium cylinders; a challenging design problem since they are susceptible to crack growth under a static pressure load (internal pressure). The manufacturing process of the neck of gas cylinders introduces small folds (up

  10. Investigation on Joining of Aluminium and Mild Steel by Friction Stud Welding

    Microsoft Academic Search

    N. Rajesh Jesudoss Hynes; P. Nagaraj; J. Angela Jennifa Sujana

    2012-01-01

    Joining of dissimilar metals has various automotive, aerospace, nuclear, chemical and cryogenic applications. The present study focuses on friction stud welding of aluminium and mild steel. Experiments had been conducted by varying the process parameters and the strength of the friction welded joints was evaluated. Experimental results show that the speed of rotation, friction time and axial shortening distance have

  11. Skew and kurtosis of low-energy heavy-ion distributions implanted in silicon and aluminium

    NASA Astrophysics Data System (ADS)

    Kisielewicz, Miko?aj

    1983-02-01

    The skew and kurtosis of 10-45 keV heavy-ion distributions in aluminium and silicon have been measured using the radiotracer and peeling technique, and compared with values calculated by the moments method of Winterbon. For Si the agreement is considered to be satisfactory; the disagreement in Al case can be explained as being due to diffusion effects.

  12. Process Simulation of Aluminium Sheet Metal Deep Drawing at Elevated Temperatures

    SciTech Connect

    Winklhofer, Johannes; Trattnig, Gernot [Virtual Vehicle Kompetenzzentrum-Das Virtuelle Fahrzeug Forschungsgesellschaft mbH (vif) Inffeldgasse 21/A/I 8010 Graz Austria (Austria); Lind, Christoph [SAG Alutech GmbH 5651 Lend Nr.25 (Austria); Sommitsch, Christof [Institute for Materials Science and Welding/Graz University of Technology Kopernikusgasse 24 8010 Graz (Austria); Feuerhuber, Hannes [weba Werkzeugbau Betriebs GmbH Weba-Strasse 2 4407 Dietach (Austria)

    2010-06-15

    Lightweight design is essential for an economic and environmentally friendly vehicle. Aluminium sheet metal is well known for its ability to improve the strength to weight ratio of lightweight structures. One disadvantage of aluminium is that it is less formable than steel. Therefore complex part geometries can only be realized by expensive multi-step production processes. One method for overcoming this disadvantage is deep drawing at elevated temperatures. In this way the formability of aluminium sheet metal can be improved significantly, and the number of necessary production steps can thereby be reduced. This paper introduces deep drawing of aluminium sheet metal at elevated temperatures, a corresponding simulation method, a characteristic process and its optimization. The temperature and strain rate dependent material properties of a 5xxx series alloy and their modelling are discussed. A three dimensional thermomechanically coupled finite element deep drawing simulation model and its validation are presented. Based on the validated simulation model an optimised process strategy regarding formability, time and cost is introduced.

  13. Effect of aluminium on nitrogen assimilation in roots of Lotus japonicus

    Microsoft Academic Search

    P. PAlOve-balang; I. MistríK

    2011-01-01

    Nitrogen assimilation and free amino acid levels were studied in Lotus japonicus L. roots exposed to low pH and aluminium stress. Both treatments reduced the activity of glutamine synthetase and glutamate synthase and their corresponding protein level in the root tissue determined by Western blotting. The decline in the rates of nitrogen assimilation was followed by a decrease in the

  14. Application of laser in seam welding of dissimilar steel to aluminium joints for thick structural components

    NASA Astrophysics Data System (ADS)

    Meco, S.; Pardal, G.; Ganguly, S.; Williams, S.; McPherson, N.

    2015-04-01

    Laser welding-brazing technique, using a continuous wave (CW) fibre laser with 8000 W of maximum power, was applied in conduction mode to join 2 mm thick steel (XF350) to 6 mm thick aluminium (AA5083-H22), in a lap joint configuration with steel on the top. The steel surface was irradiated by the laser and the heat was conducted through the steel plate to the steel-aluminium interface, where the aluminium melts and wets the steel surface. The welded samples were defect free and the weld micrographs revealed presence of a brittle intermetallic compounds (IMC) layer resulting from reaction of Fe and Al atoms. Energy Dispersive Spectroscopy (EDS) analysis indicated the stoichiometry of the IMC as Fe2Al5 and FeAl3, the former with maximum microhardness measured of 1145 HV 0.025/10. The IMC layer thickness varied between 4 to 21 ?m depending upon the laser processing parameters. The IMC layer showed an exponential growth pattern with the applied specific point energy (Esp) at a constant power density (PD). Higher PD values accelerate the IMC layer growth. The mechanical shear strength showed a narrow band of variation in all the samples (with the maximum value registered at 31.3 kN), with a marginal increase in the applied Esp. This could be explained by the fact that increasing the Esp results into an increase in the wetting and thereby the bonded area in the steel-aluminium interface.

  15. Optimization of squeeze cast parameters of LM6 aluminium alloy for surface roughness using Taguchi method

    Microsoft Academic Search

    P. Vijian; V. P. Arunachalam

    2006-01-01

    The ability to produce near net shape components with good surface finish is made possible by means of squeeze casting, a hybrid metal forming process combining features of both casting and forging in a single operation. The primary objective of this paper is to analyze the influence of the process parameters on surface roughness in squeeze casting of LM6 aluminium

  16. Hydrogen porosity in directionally solidified aluminium–copper alloys: a mathematical model

    Microsoft Academic Search

    P. D Lee; J. D Hunt

    2001-01-01

    A combined continuum and stochastic model of diffusion-controlled growth was developed to simulate the formation of porosity during the solidification of aluminium alloys. The whole population of pores was tracked, rather than just the average values. A finite difference solution of the diffusion equations was used, combined with a stochastic model of nucleation. The growth of each individual pore was

  17. Comparison of flow patterns between plasticine and aluminium alloys in hot-precision forging

    Microsoft Academic Search

    H. So; Y. F. Lin; K. W. Huang

    1997-01-01

    Flow patterns, folding problems and die filling in hot precision forging of aluminium alloys are simulated by physical modelling using plasticine. In order to study the reliability of the simulation, a forged product of complex geometry has been chosen. It is found that only the correct direction of the layers of the stacked plasticine blanks can have a similar folding

  18. Interaction of titanium diboride\\/boron nitride evaporation boats with aluminium

    Microsoft Academic Search

    Mathias Herrmann; Jan Räthel; Sören Höhn; Jens Eichler; Alexander Michaelis

    2011-01-01

    Hexagonal boron nitride\\/titanium diboride composites are widely used as evaporation boats for aluminium deposition to produce functional and decorative layers on different target materials. The lifetime of such a material is limited mainly by the interaction of the metal with the ceramic substrate, but the corrosion mechanism has still not yet been thoroughly investigated and understood. In this article the

  19. Properties of aluminium oxide thin films deposited by reactive magnetron sputtering

    Microsoft Academic Search

    Kari Koski; Jorma Hölsä; Pierre Juliet

    1999-01-01

    Amorphous aluminium oxide thin films were deposited by reactive direct current circular magnetron sputtering. The deposition process was controlled by target voltage while the target power was adjusted to a preset value by oxygen gas flow rate. This technique allows the control over the film stoichiometry and reduces the target poisoning. A pulsed power supply was used to minimise the

  20. Characterisation of aluminium oxide thin films deposited on polycarbonate substrates by reactive magnetron sputtering

    Microsoft Academic Search

    K Koski; J Hölsä; P Juliet; Z. H Wang; R Aimo; K Pischow

    1999-01-01

    Amorphous aluminium oxide thin films were deposited on polycarbonate substrates by direct current (d.c.) reactive magnetron sputtering. The thicknesses of the thin films varied between 250 nm and 3.0 ?m. The phenomena during the processing were investigated by mass spectrometer connected directly to the process chamber. Hydrocarbon radicals were observed during the plasma treatment. The thin films properties of interest

  1. Surface defects and arc generation in reactive magnetron sputtering of aluminium oxide thin films

    Microsoft Academic Search

    K Koski; J Hölsä; P Juliet

    1999-01-01

    Arcing phenomena and defect density on the surface of aluminium oxide thin films have been investigated as a function of process parameters such as pulsing frequency, substrate bias voltage, target voltage and sputtering gas pressure. The thin films were deposited by direct current reactive magnetron sputtering techniques. The deposition of the thin films was controlled by target voltage. A pulsed

  2. A study on the preparation of iron aluminium based intermetallic alloy by aluminothermic smelting technique

    Microsoft Academic Search

    S. P. Chakraborty; I. G. Sharma; D. K. Bose

    1998-01-01

    Iron aluminium based intermetallic alloys or iron aluminide alloys are usually made by conventional melting and powder processing routes. Melting is carried out either in vacuum induction melting or arc melting furnaces. However,the use of high vacuum and high temperature expensive furnaces, high cost associated with the procurement of pure individual metal components, operational problems during melting stages are some

  3. The improvement of aluminium casting process control by application of the new CRIMSON process

    Microsoft Academic Search

    X Dai; M Jolly; B Zeng

    2012-01-01

    All The traditional foundry usually not only uses batch melting where the aluminium alloys are melted and held in a furnace for long time, but also uses the gravity filling method in both Sand Casting Process (SCP) and Investment Casting Process (ICP). In the gravity filling operation, the turbulent behaviour of the liquid metal causes substantial entrainment of the surface

  4. Application of pressure infiltration to the manufacturing of aluminium matrix composite materials with different reinforcement shape

    Microsoft Academic Search

    L. A. Dobrza?ski a; M. Kremzer; A. Nagel

    Purpose: The purpose of this work is to investigate the influence of reinforcing phase's shape on structure and properties of composite materials with aluminium alloy matrix. Design\\/methodology\\/approach: The material for studies was produced by a method of pressure infiltration of the porous ceramic framework. In order to investigate the influence of reinforcing phase's shape the comparison was made between the

  5. Microplasticity initiation of aluminium matrix alloy elastically stressed in pure mode III

    Microsoft Academic Search

    N. Sarafianos; K. Agathonikos; B. Kyriakopolos

    1995-01-01

    A new theoretical analysis of pre-cracked aluminium alloy tested in pure mode III deformation is presented. The expressions obtained define the stresses developed around the crack tip as a function of the pre-crack length ? and give the possibility of determining the extent of the plastic zome with respect to the crack tip base line. For an applied stress not

  6. SUPERCONDUCTING PROPERTIES OF ALUMINIUM THIN FILMS AFTER ION IMPLANTATION AT LIQUID HELIUM TEMPERATURES (*)

    E-print Network

    Boyer, Edmond

    L-271 SUPERCONDUCTING PROPERTIES OF ALUMINIUM THIN FILMS AFTER ION IMPLANTATION AT LIQUID HELIUM concentration near AlH2. It is well-known [1] that the superconducting transition temperature Tc of metals as in the electronic density of states N(O) at the Fermi surface. In the case of weak-coupling superconductors

  7. New Type of Detachable Contact Joints for Aluminium Cell Busbar Arrangement

    Microsoft Academic Search

    Takhir T. Galemov; Alexandr M. Petrov; Yury V. Vasilyev; Lev V. Granitsky; Vladimir I. Kirko; Vladimir I. Pobyzakovb

    ~ ~ ~ The highest energy losses at power supply to aluminium cells occur at riser-busbar contact joints. In real operational situation the contact joints are greatly affected by temperature drops (from -50 to + 40ºC in Siberia). Under such thermal stresses the detachable contact joints (DCJ) reveal gradual increase of resistivity due to weakening of bolt joints and corrosion

  8. Fabrication of ultra thin anodic aluminium oxide membranes by low anodization voltages

    Microsoft Academic Search

    I. Pastore; R. Poplausks; I. Apsite; I. Pastare; F. Lombardi; D. Erts

    2011-01-01

    Formation of ultrathin anodised aluminium oxide (AAO) membranes with high aspect ratio by Al anodization in sulphuric and oxalic acids at low potentials was investigated. Low anodization potentials ensure slow electrochemical reaction speeds and formation of AAO membranes with pore diameter and thickness below 20 nm and 70 nm respectively. Minimum time necessary for formation of continuous AAO membranes was

  9. agronomie: plant genetics and breeding Effets combins de l'aluminium, du fer, et

    E-print Network

    Paris-Sud XI, Université de

    l'absorption d'ions et le rendement du riz (Oryza sativa L) en solution nutritive Vo Dinh Quang Tang vitesse d'absorption d'ammonium au tallage (45e jour), tous traitements Al-Fe-P confondus. Oryza sativa L effects of aluminium, iron and phosphorus on ion uptake and yield of rice plants (Oryza sativa L

  10. Reliability determination of aluminium electrolytic capacitors by the mean of various methods.

    E-print Network

    Paris-Sud XI, Université de

    Reliability determination of aluminium electrolytic capacitors by the mean of various methods is often calculated from reliability reports, but this method can be discussed. We compare in this article the results of various reliability reports to an accelerated ageing test of component and introduced the load

  11. Peculiarities of Harmonics Generated from Interaction of 27 ps Laser Radiation with Solid Aluminium Targets

    Microsoft Academic Search

    R A Ganeev; J A Chakera; M Raghuramaiah; A K Sharma; P A Naik; P D Gupta

    2002-01-01

    Investigations on harmonic generation in laser-matter interaction of Nd:glass laser radiation (I ? 1.5 × 1015 W cm-2, ? = 27 ps) with solid aluminium surfaces have been performed. We present here some peculiarities of spectral, temporal and spatial characteristics of harmonic radiation (up to fourth harmonic), and compare these results with those reported for the shorter pulse duration regime.

  12. Peculiarities of Harmonics Generated from Interaction of 27 ps Laser Radiation with Solid Aluminium Targets

    Microsoft Academic Search

    R. A. Ganeev; J. A. Chakera; M. Raghuramaiah; A. K. Sharma; P. A. Naik; P. D. Gupta

    2002-01-01

    Investigations on harmonic generation in laser-matter interaction of Nd:glass laser radiation (I <= 1.5 × 1015 W cm-2, tau = 27 ps) with solid aluminium surfaces have been performed. We present here some peculiarities of spectral, temporal and spatial characteristics of harmonic radiation (up to fourth harmonic), and compare these results with those reported for the shorter pulse duration regime.

  13. Mechanical and microstructural behaviour of 2024–7075 aluminium alloy sheets joined by friction stir welding

    Microsoft Academic Search

    P. Cavaliere; R. Nobile; F. W. Panella; A. Squillace

    2006-01-01

    The aim of the present work is to investigate on the mechanical and microstructural properties of dissimilar 2024 and 7075 aluminium sheets joined by friction stir welding (FSW). The two sheets, aligned with perpendicular rolling directions, have been successfully welded; successively, the welded sheets have been tested under tension at room temperature in order to analyse the mechanical response with

  14. Fatigue life enhancement of aluminium joints through mechanical and thermal prestressing

    Microsoft Academic Search

    Bård Wathne Tveiten; Arne Fjeldstad; Gunnar Härkegård; Ole Runar Myhr; Børge Bjørneklett

    2006-01-01

    This paper presents some simple and flexible methods to enhance the fatigue life of welded aluminium components. Besides enhancing the fatigue life, the proposed methods can easily be implemented into manufacturing processes. The key element of the methods is to change residual stresses from tension to compression at locations vulnerable to fatigue. This is accomplished by mechanical prestressing using elastic

  15. Assessment of the fatigue life of aluminium spot-welded and weld-bonded joints

    Microsoft Academic Search

    A. M. Pereira; J. A. M. Ferreira; F. V. Antunes; P. J. Bártolo

    2012-01-01

    In modern machinery and automobile structures weight reduction and increased durability are the main issues in design. In these applications, lap welded and\\/or bonded joints are widely used; therefore, tools are needed to accurately predict their fatigue life. This paper is concerned with the fatigue strength of single lap joints formed with thin plates of 6082-T6 aluminium alloy using a

  16. Combustion synthesis and development of Ti–O–C aluminium composites

    Microsoft Academic Search

    Krzysztof Naplocha

    2011-01-01

    Aluminium matrix composite reinforced with Ti compounds was successfully fabricated by SHS combustion synthesis and squeeze casting course. Prepared samples from mixture containing Ti, C and Al2O3 fibres were heated in microwave reactor to ignite synthesis and produce porous preform for subsequent infiltrating with liquid metal. Studies showed that synthesizing temperature has been remarkably increased by applying higher magnetron power

  17. Observation of surface plasmons by transition radiation from smooth aluminium films

    E-print Network

    Boyer, Edmond

    L-167 Observation of surface plasmons by transition radiation from smooth aluminium films A'une résonance due aux plasmons de surface, dans le spectre du rayonnement de transition de films d We report the first observation of a strong resonance due to surface plasmons in the transition radia

  18. Development of a solid surface fluorescence-based sensing system for aluminium monitoring in drinking water

    Microsoft Academic Search

    J. F. García Reyes; P. Ortega Barrales; A. Molina Díaz

    2005-01-01

    A novel, single and robust solid surface fluorescence-based sensing device assembled in a continuous flow system has been developed for the determination of trace amounts of aluminium in water samples. The proposed method is based on the transient immobilization of the target species on an appropriate active solid sensing zone (C18 silica gel). The target species was the fluorogenic chelate,

  19. COMBUSTION AUTONOME DE SPHERES D'ALUMINIUM R. Bouriannes et N. Mnson

    E-print Network

    Paris-Sud XI, Université de

    COMBUSTION AUTONOME DE SPHERES D'ALUMINIUM R. Bouriannes et N. Mànson Laboratoire dlEnergétiquede l dispositif pour l'étude de la combustion autonome d'une sphère d'alumi- nium. On définit une pression p", fonction du mélange comburant, au-dessus de laquel- le la combuÇtion est totale. L'aspect de la combustion

  20. Aluminium siting in the ZSM-5 framework by combination of high resolution 27

    E-print Network

    Sklenak, Stepan

    Aluminium siting in the ZSM-5 framework by combination of high resolution 27 Al NMR and DFT converted to 27 Al isotropic chemical shifts using the experimental isotropic chemical shift of 60.0 ppm isotropic chemical shifts of 50.0 and 54.7 ppm correspond to Al atoms in the T20 and T6 sites, respectively

  1. TEM interfacial characteristics of thermosonic gold wire bonding on aluminium metallization

    Microsoft Academic Search

    H. Xu; C. Liu; V. V. Silberschmidt; Z. Chen; M. Sivakumar

    2009-01-01

    A native alumina thin film existing on aluminium and its evolution in thermosonic gold wire bonding were characterized using high resolution transmission electron microscopy (HR TEM). It has been found that the partly fracture of this alumina film by the ultrasonic vibration allows the interdiffusion at the Au\\/Al interface, such that the intermetallic compounds (IMCs) are formed. The IMCs are

  2. Strength of the Aluminium Alloy 6082-T6 Under High Strain-Rate Conditions

    Microsoft Academic Search

    J. J. Harrigan; J. C. F. Millett; N. K. Bourne

    2007-01-01

    The measurement of shear strength via the use of lateral stress gauges has been shown to be a viable technique in a number of materials. An experimental investigation on the intermediate-rate behaviour and shock response of the aluminium alloy, 6082-T6, is reported here. Results obtained using the lateral stress gauge technique show that the shear strength increases with impact stress.

  3. STRENGTH OF THE ALUMINIUM ALLOY 6082-T6 UNDER HIGH STRAIN-RATE CONDITIONS

    Microsoft Academic Search

    J. J. Harrigan; J. C. F. Millett; N. K. Bourne

    2007-01-01

    The measurement of shear strength via the use of lateral stress gauges has been shown to be a viable technique in a number of materials. An experimental investigation on the intermediate-rate behaviour and shock response of the aluminium alloy, 6082-T6, is reported here. Results obtained using the lateral stress gauge technique show that the shear strength increases with impact stress.

  4. Experimental study on process of precision forging of an aluminium-alloy rotor

    Microsoft Academic Search

    Debin Shan; Fang Liu; Wenchen Xu; Yan Lu

    2005-01-01

    This paper describes the process of precision forging of an aluminium-alloy rotor with 23 radial twist blades. Fully-enclosed die forging with isothermal condition was carried out to form the complexity shape rotor. A combined female die was designed to solve the die releasing. Several forming schemes were employed to reduce the forging pressure or to improve the die fill in

  5. Porous 'Ouzo-effect' silica-ceria composite colloids and their application to aluminium corrosion protection.

    PubMed

    Hollamby, Martin J; Borisova, Dimitriya; Möhwald, Helmuth; Shchukin, Dmitry

    2012-01-01

    By exploiting spontaneous emulsification to prepare porous SiO(2) particles, we report the formation of porous CeO(2)@SiO(2) hybrid colloids and their incorporation into a silica-zirconia coating to improve the corrosion protection of aluminium. PMID:22057048

  6. Embedded Fibre Bragg Grating Array Sensors in Aluminium Alloy Matrix by Ultrasonic Consolidation

    E-print Network

    Neirotti, Juan Pablo

    ABSTRCT Fibre Bragg Grating (FBG) array sensors have been successfully embedded in aluminium alloy matrix by ultrasonic consolidation (UC) technique. The temperature and loading responses of the embedded FBG arrays that FBG array sensors can be embedded in metal matrix together with other passive and active fibres

  7. A Real time predictive maintenance system of Aluminium Electrolytic Capacitors used in

    E-print Network

    Paris-Sud XI, Université de

    A Real time predictive maintenance system of Aluminium Electrolytic Capacitors used and a predictive maintenance system of an electrolytic capacitor used in Uninterrupted Power Supplies (UPS) and the capacitance C values of the electrolytic capacitors. Simulation and experimental results are presented

  8. Lanthanide compounds as environmentally-friendly corrosion inhibitors of aluminium alloys: a review

    Microsoft Academic Search

    M. Bethencourt; F. J. Botana; J. J. Calvino; M. Marcos; M. A. RodrÍguez-Chacón

    1998-01-01

    Currently, chromates are among the most common substances used as inhibitors or incorporated in anticorrosive pretreatments of aluminium alloys. However, these compounds are highly toxic and their use produces serious environmental hazards. Consequently, an intense research effort is being undertaken to replace chromates by more ecological compounds. In recent years, several authors have begun studies of the behaviour of lanthanide

  9. Antibacterial drugs as corrosion inhibitors for corrosion of aluminium in hydrochloric solution

    Microsoft Academic Search

    M Abdallah

    2004-01-01

    The corrosion behavior of aluminium in 2 M HCl solution in the absence and presence of four compounds of antibacterial drug was investigated using hydrogen evolution, weight loss, and potentiostatic polarization techniques. It was found that, the inhibition efficiency of these compounds depends on their concentration and chemical structure. The inhibitive action of these compounds was discussed in terms of

  10. XPS and corrosion studies on zinc phosphate coated 7075-T6 aluminium alloy

    Microsoft Academic Search

    W. F. Heung; Y. P. Yang; P. C. Wong; K. A. R. Mitchell; T. Foster

    1994-01-01

    X-ray photoelectron spectroscopy (XPS), combined with scanning electron microscopy (SEM), weight loss tests and atomic absorption spectroscopy (AAS), has been applied to investigate the corrosion protection properties of zinc phosphate when coated on 7075-T6 aluminium alloy. XPS is consistent with the coating process leading to both physically adsorbed and chemically absorbed zinc. The former is washed away by ultrasonic washing,

  11. Observations related to the phosphating of aluminium alloy 7075-T6 using a spraying technique

    Microsoft Academic Search

    J. Fang; P. C. Wong; K. A. R. Mitchell; T. Foster

    1998-01-01

    An initial review is made of the effects of changing parameters involved in forming a zinc phosphate coating layer by spraying an aluminium alloy 7075-T6. Various coatings were evaluated by X-ray photoelectron spectroscopy, scanning electron microscopy and adhesion tests. The coating solution reported represents a modification of that previously used for coating the same system by the dipping method (J.

  12. Experimental studies on the quasi-static axial crushing of steel columns filled with aluminium foam

    Microsoft Academic Search

    M. Seitzberger; F. G. Rammerstorfer; R. Gradinger; H. P. Degischer; M. Blaimschein; C. Walch

    2000-01-01

    Experimental investigations are carried out in order to study the effects of different tube and filler arrangements on the crushing behaviour of axially compressed tubular crush elements. To this end quasistatic experiments are performed on monotubal and bitubal, empty and filled steel profiles with different materials, dimensions and cross-sectional shapes. Aluminium foam, produced by a powder metallurgical production process, is

  13. Static and dynamic axial crushing of square thin-walled aluminium extrusions

    Microsoft Academic Search

    M. Langseth; O. S. Hopperstad

    1996-01-01

    An experimental investigation was carried out to study the behaviour of square thin-walled aluminium extrusions in alloy AA6060 subjected to axial loading. Both static and dynamic tests were performed and the primary variables were the wall thickness and temper of the square tubes and the impact velocity of the projectile. The mass of the projectile in the dynamic tests was

  14. Analysis of the effects of controlled shot peening on fatigue damage of high strength aluminium alloys

    Microsoft Academic Search

    S. Curtis; E. R. de los Rios; C. A. Rodopoulos; A. Levers

    2003-01-01

    The use of two micro-mechanical models for notch sensitivity and fatigue life allowed the development of boundary conditions that would evaluate potential life improvement after controlled shot peening (CSP) in high strength aluminium alloys. The boundary conditions describe the state of equal weight between surface roughening and residual stresses and the implication of material and loading parameters. From the boundary

  15. The effect of heating shot peened sheets and thin plates of aluminium alloys

    Microsoft Academic Search

    B. Cina; T. Kaatz; I. Eldror

    1990-01-01

    2024, 7075 and 7475 aluminium alloy sheet and thin plate specimens shot peened to various intensities and subsequently exposed for periods up to 500 h at temperatures up to 120 ° C showed significant decreases in the level of residual stress induced by the shot peening and significant changes in geometrical contour even for exposure temperatures as low as 80

  16. Effect of pitting corrosion on fatigue performance of shot-peened aluminium alloy 7075-T651

    Microsoft Academic Search

    U. Zupanc; J. Grum

    2010-01-01

    Pitting corrosion has a major influence on aging of structural elements made of high-strength aluminium alloys as corrosion pits lead to earlier fatigue crack initiation under tensile dynamic loading. A cause of fatigue crack initiation in a corrosive medium is a stress concentration at a corroded area. In order to improve material resistance to corrosion fatigue it is necessary to

  17. Enhancement of thermoelectric figure-of-merit by resonant states of aluminium doping in lead selenide

    E-print Network

    Zhang, Qinyong

    By adding aluminium (Al) into lead selenide (PbSe), we successfully prepared n-type PbSe thermoelectric materials with a figure-of-merit (ZT) of 1.3 at 850 K. Such a high ZT is achieved by a combination of high Seebeck ...

  18. Aluminium coating of lead zirconate titanate—A study of cold spray variables

    Microsoft Academic Search

    Peter C. King; Saden Zahiri; Mahnaz Jahedi; James Friend

    2010-01-01

    Cold spray was used to deposit conductive aluminium coatings onto lead zirconate titanate (PZT) piezoceramics. The optimisation of processing parameters was explored. Grain removal from the PZT surface due to the impact of Al particles was reduced by increasing the average particle velocity. Surface domain reorientation was detected by X-ray diffraction (XRD). Substrate temperatures during spraying were maintained at a

  19. Die erosion and its effect on soldering formation in high pressure die casting of aluminium alloys

    Microsoft Academic Search

    Z. W Chen; M. Z Jahedi

    1999-01-01

    Erosion of the die material during die filling has long been regarded as a possible damage mechanism of dies in high pressure die casting (HPDC) of aluminium alloys. Melt impingement and erosion have also been proposed to be an important step leading to die soldering. However, there is little information in the literature on the direct measurement of any kind

  20. Modelling the environmental impact of an aluminium pressure die casting plant and options for control

    Microsoft Academic Search

    Belmira Neto; Carolien Kroeze; Leen Hordijk; Carlos Costa

    2008-01-01

    This study describes a model (MIKADO) to analyse options to reduce the environmental impact of aluminium die casting. This model will take a company perspective, so that it can be used as a decision-support tool for the environmental management of a plant. MIKADO can be used to perform scenario analyses to analyse the impact on the environment of different strategies,

  1. Characterisation of oxidised aluminium powder: Validation of a new anodic oxidation bench

    Microsoft Academic Search

    Nicolas Gascoin; Philippe Gillard; Guillaume Baudry

    2009-01-01

    Aluminium powder is of major interest in many applications but it presents a risk due to its high explosibility, particularly when dispersed in air. The safety is directly linked to the particles oxidation because the Minimum Ignition Energy (MIE), which is required to initiate an Al dust explosion, increases with the oxide layer thickness. This study provides a controlled method

  2. Interfacial characteristics of silicon carbide-coated boron-reinforced aluminium matrix composites

    Microsoft Academic Search

    K. Prewo; G. McCarthy

    1972-01-01

    The fibre-matrix interfacial region has been examined in BORSIC®-aluminium. The structure of this interface and that of the silicon carbide-boron interface have been revealed by transmission electron microscopy. Observations of composite fracture surfaces have indicated the considerable strength of the fibre-matrix interface and have shown that interfacial failure is seldom a mode of composite fracture.

  3. Wear performance of aluminium alloy composites containing unidirectionally-oriented silicon carbide coated boron fibres

    Microsoft Academic Search

    Y. Sahin; S. Murphy

    1996-01-01

    The friction and wear behaviour of continuous, silicon carbide coated, unidirectional boron fibre reinforced aluminium alloy composites produced by a metal infiltration technique was investigated. A pin-on-disc type apparatus was employed for determining the sliding wear rate and the coefficient of friction in a direction normal to the fibre axis. The effects of applied load and volume fraction of fibre

  4. Anomalous energy loss distributions of alpha particles in heavily implanted thin aluminium films

    Microsoft Academic Search

    K. M. Barfoot; S. E. Donnelly; R. Werz; P. Rietveld

    1982-01-01

    Anomalous energy loss distributions of Gd alpha particles have been observed in heavily implanted thin aluminium films. It is surmised that thin film micro-wrinkling is responsible for the observed effect and that the novel technique of energy loss spectral analysis (ELSA) should be useful in studies of the topography of such films.

  5. Effects of heat treatments on the microstructure and mechanical properties of a 6061 aluminium alloy

    Microsoft Academic Search

    D. Maisonnette; M. Suery; D. Nelias; P. Chaudet; T. Epicier

    2011-01-01

    This paper describes the mechanical behavior of the 6061-T6 aluminium alloy at room temperature for various previous thermal histories representative of an electron beam welding. A fast-heating device has been designed to control and apply thermal loadings on tensile specimens. Tensile tests show that the yield stress at ambient temperature decreases if the maximum temperature reached increases or if the

  6. Microstructure and wear behaviour of aluminium alloys containing embedded nanoscaled lead dispersoids

    Microsoft Academic Search

    Victoria Bhattacharya; K Chattopadhyay

    2004-01-01

    We report the early stage friction and wear characteristics of aluminium containing nanosized lead dispersions. The nanocomposite was produced by rapid solidification. The experimental results indicate a significant decrease in friction and wear rate in comparison to its coarse grained counterparts. We show that the observed results suggest an adhesive type of wear mechanism. However, increase in hardness due to

  7. Investigation of feathery crystals developed in weld metal in aluminium alloys by SAM and TEM

    Microsoft Academic Search

    M. Kato; K. Nishio; T. Yamaguchi; T. Nokami

    1997-01-01

    The macroscopic solidification structures developed in the weld metal of aluminium alloys are generally columnar crystals and equiaxed dendrites. The development of these macrostructures depends on the welding conditions. Feathery crystals are sometimes developed during low-speed GTA (TIG) welding. This paper describes an investigation of the characteristics of feathery crystals by scanning acoustic microscopy (SAM) and transmission electron microscopy (TEM).

  8. Effect of pre-stretching on microstructure of aged 2524 aluminium alloy

    Microsoft Academic Search

    Li-wei QUAN; Gang ZHAO; Sam GAO; Barry C. MUDDLE

    2011-01-01

    The effects of pre-stretching following solution treatment on the hardness and microstructures of aged 2524 aluminium alloy at 170 °C were studied. Ageing hardness values under different pre-stretching conditions were measured, and the corresponding microstructures were characterized by transmission electron microscopy (TEM). The results show that compared with unstretched samples, the peak hardness is increased and the time to reach

  9. Influence of heat treatment on the microstructure and mechanical properties of 6005 and 6082 aluminium alloys

    Microsoft Academic Search

    Gra?yna Mrówka-Nowotnik; Jan Sieniawski

    2005-01-01

    The main task of this work was to study the influence of the cooling conditions after homogenization of the 6082 aluminium alloys. The effect of the solution heat treatment temperature on the mechanism and ageing kinetics of the two commercial wrought aluminum alloys 6005 and 6082 was also analyzed. The alloys were heat treated—T4 with a wide range of solution

  10. Effect of the nature of grain boundary regions on cavitation of a superplastically deformed aluminium alloy

    Microsoft Academic Search

    J. J. Blandin; B. Hong; A. Varloteaux; M. Suery

    1996-01-01

    Superplastic deformation of aluminium alloys induces cavity formation throughout the material, so that superplastic forming usually requires to be carried out under superimposed gas pressure to minimize strain-induced damage. This paper deals with the beneficial effects of heat treatment at high temperature for several hours before deformation on cavitation behaviour of a superplastically deformed 7475 alloy. Transmission electron microscopy observations

  11. Straining mechanisms in aluminium alloy 6056. In-situ investigation by transmission electron microscopy

    Microsoft Academic Search

    François Delmas; Marie Vivas; Philippe Lours; Marie-José Casanove; Alain Couret; Armand Coujou

    2003-01-01

    TEM in-situ straining tests, performed in precipitation hardened aluminium alloy 6056-T6, show that precipitates are sheared or by-passed by dislocations. By-passing, assisted by dislocation cross-slip, results in the formation and stress-induced spreading of non-planar loops. The relationship between those elementary mechanisms and the mechanical properties of the alloy is discussed.

  12. Hydrogen porosity in directional solidified aluminium-copper alloys: in situ observation

    Microsoft Academic Search

    P. D. Lee; J. D. Hunt

    1997-01-01

    Using a temperature gradient stage and real time micro-focus radiography the formation of porosity was observedin situ during the solidification of aluminium-copper alloys. Pore morphology was characterized both in the final structure and as a function of temperature during solidification, providing a qualitative insight into the relative importance of the competing physical processes. The effect of solidification velocity, thermal gradient

  13. Hot-crack test for aluminium alloys welds using TIG process , F. Deschaux1

    E-print Network

    Paris-Sud XI, Université de

    Hot-crack test for aluminium alloys welds using TIG process A. Niel1,a , F. Deschaux1 , C many defects such as hot cracking (also known as hot tearing or solidification cracking). It is one the emergence of hot tearing with characteristic length of material by means of different measures. 1 Hot

  14. Synthesis of ettringite: a way to deal with the acid wastewaters of aluminium anodising industry

    Microsoft Academic Search

    E. Álvarez-Ayuso; H. W. Nugteren

    2005-01-01

    Synthesis of ettringite from acid wastewaters of the aluminium anodising industry has been studied as a possible route of reducing the emissions to the environment, recovering at the same time resource materials as a useful marketable mineral. Wastewaters of different concentrations have been subjected to the process of synthesis suspending calcium oxide and calcium aluminate powders at different time and

  15. Metallized graphite as an improved cathode material for aluminium/air batteries

    NASA Astrophysics Data System (ADS)

    Mukherjee, Ambick; N. Basumallick, Indra

    1993-06-01

    This paper reports the fabrication of metallized (Pt, Ni, Cu, Fe, Co) graphite cathodes by an electrodeposition method from an appropriate electrolytic bath, together with the performance characteristics of specially-designed aluminium/air cells that utilize these cathodes. In these cells, the aluminium electrodes were separated by a glass-jacket separator. The latter prevents mixing of hydrogen gas evolved due to the corrosion of the aluminium electrode. While the open-circuit voltage of the cells is virtually invariant, the short-circuit current and discharge behaviour are markedly dependent upon the choice of catalytic metal. The discharge profiles are improved markedly for cells with a Pt-, Ni- or Cu-coated graphite air cathode, but the reverse is found for Fe- and Co-coated cathodes. The behaviour is explained in terms of chemisorption and the better catalytic activity of Pt, Ni and Cu. These results suggest that Ni- and Cu-coated graphite air cathodes are promising low-cost and efficiennt electrodes for aluminium/air batteries.

  16. The formation of nanoporous membranes from anodically oxidized aluminium and their application to Li rechargeable batteries

    Microsoft Academic Search

    A. Mozalev; S. Magaino; H. Imai

    2001-01-01

    A method for the preparation of nanoporous dielectric membranes from anodically oxidized aluminium is described. Pores of an initially formed free anodic alumina film were protected with gelatin gel, and the oxide barrier layer was chemically dissolved from bottom side of the film. The method is advantageous in that it permits complete removal of the barrier layer and fabrication of

  17. Determination of aluminium in a "nimonic" alloy by activation with fast neutrons.

    PubMed

    Quigley, D A; Trussler, J W

    1969-03-01

    Aluminium at the 6% level was determined in a 15-component "nimonic" alloy with a coefficient of variation of +/-8.7% by using fast-neutron activation followed by pulse-height analysis of gamma-ray spectra. The possibility of determining chromium, iron, cobalt and manganese is discussed. PMID:18960521

  18. Wear behaviour of cemented carbide tools in dry machining of aluminium alloy

    Microsoft Academic Search

    G. List; M. Nouari; D. Géhin; S. Gomez; J. P. Manaud; Y. Le Petitcorps; F. Girot

    2005-01-01

    Several causes of tool wear have been investigated in dry machining of aluminium alloy with cemented carbide insert; some of the most important are: adhesion and diffusion. The formation of built-up edge (BUE) and adhesive layer on the tool rake face degrades on the one hand, the shape and efficiency of cutting tool and on the other hand, the surface

  19. Aluminium foams as structured supports for volatile organic compounds (VOCs) oxidation

    Microsoft Academic Search

    Oihane Sanz; F. Javier Echave; Maialen Sánchez; Antonio Monzón; Mario Montes

    2008-01-01

    In this work aluminium foams were studied as structured supports for the elimination of volatile organic compounds (VOCs, toluene). Foams of different pore density, 10, 20 and 40pores per inch (ppi), were used in an anodisation process to produce a very thin layer of alumina. This alumina layer was impregnated with the active phase, platinum, by wet impregnation. Anodisation process

  20. The alkaline aluminium hydrogen peroxide semi-fuel cell for the HUGIN 3000 autonomous underwater vehicle

    Microsoft Academic Search

    O. Hasvold; Kjell Håvard Johansen

    2002-01-01

    This semi-fuel cell uses a circulating alkaline electrolyte, aluminium (Al) anodes and maintain the oxidant concentration in the electrolyte by continuously adding hydrogen peroxide (HP) to the electrolyte. This concept resulted in a safe battery that works at ambient pressure (balanced) and with sufficient power and energy density to allow the AUV HUGIN 3000 underwater surveys of up to 50

  1. An experimental investigation of constraint effects on mixed mode fracture initiation in a ductile aluminium alloy

    Microsoft Academic Search

    Y. Arun Roy; R. Narasimhan; P. R. Arora

    1999-01-01

    The effect of constraint on ductile fracture initiation from a notch tip under mode I and mixed mode (involving modes I and II) loading is investigated. To this end, mixed mode fracture experiments are performed with Compact Tension Shear (or CTS) specimen of a ductile 2014-O aluminium alloy. The constraint effects are investigated by considering specimens with two crack length

  2. Aluminium induced oxidative stress results in decreased mitochondrial biogenesis via modulation of PGC-1? expression

    SciTech Connect

    Sharma, Deep Raj; Sunkaria, Aditya; Wani, Willayat Yousuf; Sharma, Reeta Kumari; Kandimalla, Ramesh J.L. [Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh 160012 (India); Bal, Amanjit [Department of Histopathology, Postgraduate Institute of Medical Education and Research, Chandigarh (India); Gill, Kiran Dip, E-mail: kdgill2002@yahoo.co.in [Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh 160012 (India)

    2013-12-01

    The present investigation was carried out to elucidate a possible molecular mechanism related to the effects of aluminium-induced oxidative stress on various mitochondrial respiratory complex subunits with special emphasis on the role of Peroxisome proliferator activated receptor gamma co-activator 1? (PGC-1?) and its downstream targets i.e. Nuclear respiratory factor-1(NRF-1), Nuclear respiratory factor-2(NRF-2) and Mitochondrial transcription factor A (Tfam) in mitochondrial biogenesis. Aluminium lactate (10 mg/kg b.wt./day) was administered intragastrically to rats for 12 weeks. After 12 weeks of exposure, we found an increase in ROS levels, mitochondrial DNA oxidation and decrease in citrate synthase activity in the Hippocampus (HC) and Corpus striatum (CS) regions of rat brain. On the other hand, there was a decrease in the mRNA levels of the mitochondrial encoded subunits–NADH dehydrogenase (ND) subunits i.e. ND1, ND2, ND3, Cytochrome b (Cytb), Cytochrome oxidase (COX) subunits i.e. COX1, COX3, ATP synthase (ATPase) subunit 6 along with reduced expression of nuclear encoded subunits COX4, COX5A, COX5B of Electron transport chain (ETC). Besides, a decrease in mitochondrial DNA copy number and mitochondrial content in both regions of rat brain was observed. The PGC-1? was down-regulated in aluminium treated rats along with NRF-1, NRF-2 and Tfam, which act downstream from PGC-1? in aluminium treated rats. Electron microscopy results revealed a significant increase in the mitochondrial swelling, loss of cristae, chromatin condensation and decreases in mitochondrial number in case of aluminium treated rats as compared to control. So, PGC-1? seems to be a potent target for aluminium neurotoxicity, which makes it an almost ideal target to control or limit the damage that has been associated with the defective mitochondrial function seen in neurodegenerative diseases. - Highlights: • Aluminium decreases the mRNA levels of mitochondrial and nuclear encoded subunits. • It decreases the mtDNA copy number and mitochondrial content in rat brain. • It down-regulates the mRNA and protein levels of PGC-1?, NRF-1, NRF-2 and Tfam. • It also disturbs the mitochondrial or nuclear architecture of neurons. • Finally it also decreases mitochondrial number in HC and CS regions of rat brain.

  3. Additives in plastics.

    PubMed Central

    Deanin, R D

    1975-01-01

    The polymers used in plastics are generally harmless. However, they are rarely used in pure form. In almost all commercial plastics, they are "compounded" with monomeric ingredients to improve their processing and end-use performance. In order of total volume used, these monomeric additives may be classified as follows: reinforcing fibers, fillers, and coupling agents; plasticizers; colorants; stabilizers (halogen stabilizers, antioxidants, ultraviolet absorbers, and biological preservatives); processing aids (lubricants, others, and flow controls); flame retardants, peroxides; and antistats. Some information is already available, and much more is needed, on potential toxicity and safe handling of these additives during processing and manufacture of plastics products. PMID:1175566

  4. Quaternary deposit control additives

    SciTech Connect

    Campbell, C.B.

    1986-04-08

    This patent describes a lubricating oil composition. These additives consist of a major portion of an oil of lubricating viscosity and a dispersant effective amount of quaternized polyoxyalkylene amine salt additive of molecular weight from about 500 to about 2500. The polyoxyalkylene moiety consists of 1 to 30 oxyalkylene units selected from oxyalkylene units having 2 to 4 carbon atoms. The amine moiety consists of from 1 to about 12 amine nitrogen atoms and from about 2 to 40 carbon atoms, and further consisting of a connecting moiety linking the polyoxyalkylene moiety and the amine moiety.

  5. Exposures in the alumina and primary aluminium industry: an historical review.

    PubMed

    Benke, G; Abramson, M; Sim, M

    1998-04-01

    We reviewed specific chemical exposures and exposure assessment methods relating to published and unpublished epidemiological studies in the alumina and primary aluminium industry. Our focus was to review limitations in the current literature and make recommendations for future research. Although some of the exposures in the smelting of aluminium have been well characterised, particularly in potrooms, little has been published regarding the exposures in bauxite mining and alumina refining. Past epidemiological studies in the industry have concentrated on the smelting of aluminium, with many limitations in the methodology used in their exposure assessment. We found that in aluminium smelting, exposures to fluorides, coal tar pitch volatiles (CTPV) and sulfur dioxide (SO2) have tended to decrease in recent years, but insufficient information exists for the other known exposures. Although excess cancers have been found among workers in the smelting of aluminium, the exposure assessment methods in future studies need to be improved to better characterise possible causative agents. The small number of cohort studies has been a factor in the failure to identify clear exposure-response relationships for respiratory diseases. A dose-response relationship has been recently described for fluoride exposure and bronchial hyper-responsiveness, but whether fluorides are the causative agent, co-agent or simply markers for the causative agent(s) for potroom asthma, remains to be determined. Published epidemiological studies and quantitative exposure data for bauxite mining and alumina refining are virtually non-existent. Determination of possible exposure-response relationships for this part of the industry through improved exposure assessment methods should be the focus of future studies. PMID:9684558

  6. Decrements in cognitive performance in metal inert gas welders exposed to aluminium

    PubMed Central

    Akila, R.; Stollery, B. T.; Riihimaki, V.

    1999-01-01

    OBJECTIVES: Often little has been discovered of the cognitive functions affected by occupational toxins because many functions cooperate to produce the single performance scores typically reported from neuropsychological tests. To facilitate the interpretation of neuropsychological scores, the issue of occupational exposure to aluminium was examined with an approach intended to increase understanding of those cognitive processes that may be affected. METHODS: The investigation was a cross sectional study of asymptomatic aluminium welders and a reference group of mild steel welders. Based on urinary aluminium concentrations, welders were classified into a reference (n = 28), low (n = 27), and high (n = 24) exposure group. The mean urinary aluminium concentrations were 0.46, 2.25, and 9.98 mumol/l, respectively. A comprehensive neuropsychological examination was undertaken to assess psychomotor function, simple visual reaction time, attention related tasks, verbal and visual or visuospatial abilities as well as verbal and visual learning and memory. RESULTS: Aluminium welders showed no impairment on the finger tapping, Santa Ana dexterity, simple visual reaction times, any of the verbal memory tasks, the similarities subtest of Wechsler adult intelligence scale, or the Stroop task. However, the low exposed group performed poorer on the memory for designs and on more difficult block design items demanding preliminary visuospatial analysis. The time limited synonym task, embedded figures, digit symbol speed, and the backward counting component of the divided attention task showed exposure-response relations. CONCLUSIONS: The impairments found were circumscribed. When the neuropsychological tasks were scored to show some of the underlying theoretical cognitive structures, the results indicated that performance difficulties were mainly detected in tasks requiring working memory, particularly that relating to processing of visuospatial information. There was also evidence that such impairments are more readily found in time limited tasks involving visually presented material, in which effective visual scanning combined with control of working memory is demanded.   PMID:10615297

  7. Additive Versus Subtractive Manufacturing

    NSDL National Science Digital Library

    For manufacturing students learning the basics, this page from SnoCAMP would be a useful addition to in-class instruction. The webpage combines photographs of examples with descriptive text. This would be a good introduction for students learning the basics about manufacturing.

  8. Fluency with Basic Addition

    ERIC Educational Resources Information Center

    Garza-Kling, Gina

    2011-01-01

    Traditionally, learning basic facts has focused on rote memorization of isolated facts, typically through the use of flash cards, repeated drilling, and timed testing. However, as many experienced teachers have seen, "drill alone does not develop mastery of single-digit combinations." In contrast, a fluency approach to learning basic addition

  9. Arrillaga Sports Center Addition,

    E-print Network

    Bogyo, Matthew

    BioE/ChemE Building emical ding, ion Arrillaga Sports Center Addition, New EV Graduate Student Sports Ctr Music Rehearsal Facility Credit Union Recycling Center Children's Center of the Stanford and Astrophysics Arrillaga Center for Sports and Recreation Herrin Labs 155 Blackwelder Highrise Quillen Highrise

  10. Electrophilic addition of astatine

    Microsoft Academic Search

    Yu. V. Norseev; L. Vasaros; D. D. Nhan; N. K. Huan

    1988-01-01

    It has been shown for the first time that astatine is capable of undergoing addition reactions to unsaturated hydrocarbons. A new compound of astatine, viz., ethylene astatohydrin, has been obtained, and its retention numbers of squalane, Apiezon, and tricresyl phosphate have been found. The influence of various factors on the formation of ethylene astatohydrin has been studied. It has been

  11. Additional Sources of Information

    Cancer.gov

    Additional Sources of Information Developing Medical Imaging Drug and Biological Products Part 1: Conducting Safety Assessments [PDF] (Issued 6/17/2004, Posted 6/17/2004) Part 2: Clinical Indications [PDF] (Issued 6/17/2004, Posted 6/17/2004) Content

  12. Boron addition to alloys

    SciTech Connect

    Coad, B. C.

    1985-08-20

    A process for addition of boron to an alloy which involves forming a melt of the alloy and a reactive metal, selected from the group consisting of aluminum, titanium, zirconium and mixtures thereof to the melt, maintaining the resulting reactive mixture in the molten state and reacting the boric oxide with the reactive metal to convert at least a portion of the boric oxide to boron which dissolves in the resulting melt, and to convert at least portion of the reactive metal to the reactive metal oxide, which oxide remains with the resulting melt, and pouring the resulting melt into a gas stream to form a first atomized powder which is subsequently remelted with further addition of boric oxide, re-atomized, and thus reprocessed to convert essentially all the reactive metal to metal oxide to produce a powdered alloy containing specified amounts of boron.

  13. Electrophilic addition of astatine

    SciTech Connect

    Norseev, Yu.V.; Vasaros, L.; Nhan, D.D.; Huan, N.K.

    1988-03-01

    It has been shown for the first time that astatine is capable of undergoing addition reactions to unsaturated hydrocarbons. A new compound of astatine, viz., ethylene astatohydrin, has been obtained, and its retention numbers of squalane, Apiezon, and tricresyl phosphate have been found. The influence of various factors on the formation of ethylene astatohydrin has been studied. It has been concluded on the basis of the results obtained that the univalent cations of astatine in an acidic medium is protonated hypoastatous acid.

  14. Generalized Additive Models

    Microsoft Academic Search

    Trevor Hastie; Robert Tibshirani

    1986-01-01

    Likelihood-based regression models such as the normal linear regression model and the linear logistic model, assume a linear (or some other parametric) form for the covariates $X_1, X_2, \\\\cdots, X_p$. We introduce the class of generalized additive models which replaces the linear form $\\\\sum \\\\beta_jX_j$ by a sum of smooth functions $\\\\sum s_j(X_j)$. The $s_j(\\\\cdot)$'s are unspecified functions that are

  15. The partial space qualification of a vertically aligned carbon nanotube coating on aluminium substrates for EO applications.

    PubMed

    Theocharous, Evangelos; Chunnilall, Christopher J; Mole, Ryan; Gibbs, David; Fox, Nigel; Shang, Naigui; Howlett, Guy; Jensen, Ben; Taylor, Rosie; Reveles, Juan R; Harris, Oliver B; Ahmed, Naseer

    2014-03-24

    The fabrication of NanoTube Black, a Vertically Aligned carbon NanoTube Array (VANTA) on aluminium substrates is reported for the first time. The coating on aluminium was realised using a process that employs top down thermal radiation to assist growth, enabling deposition at temperatures below the substrate's melting point. The NanoTube Black coatings were shown to exhibit directional hemispherical reflectance values of typically less than 1% across wavelengths in the 2.5 µm to 15 µm range. VANTA-coated aluminium substrates were subjected to space qualification testing (mass loss, outgassing, shock, vibration and temperature cycling) before their optical properties were re-assessed. Within measurement uncertainty, no changes to hemispherical reflectance were detected, confirming that NanoTube Black coatings on aluminium are good candidates for Earth Observation (EO) applications. PMID:24664077

  16. Self-assembly of aluminium-salen coupled nanostructures from encoded modules with cleavable disulfide DNA-linkers.

    PubMed

    Brown, Raymond S; Nielsen, Morten; Gothelf, Kurt V

    2004-07-01

    DNA-directed coupling of organic modules by formation of stable aluminium-salen complexes, makes possible the subsequent reductive cleavage of disulfide linkers and release of the two oligonucleotide chains attached to each building-block. PMID:15216332

  17. Active coatings for SiC particles to reduce the degradation by liquid aluminium during processing of aluminium matrix composites: study of interfacial reactions.

    PubMed

    Ureña, A.; Rodrigo, P.; Baldonedo, J. L.; Gil, L.

    2001-02-01

    The application of a surface coating on SiC particles is studied as an alternative means of solving problems of reactivity between SiC reinforcements and molten aluminium and problems of low wetting which limit the application of casting routes for fabrication of Al-SiCp composites. The selected active barrier was a ceramic composed of SiO2, which was generated by controlled oxidation of the SiC particles. The coating behaves as an active barrier, preventing a direct reaction between molten aluminium and SiC to form Al4C3 as the main degradation product. At the same time, the SiO2 provokes other interfacial reactions, which are responsible for an improvement in wetting behaviour. Composites were prepared by mixing and compacting SiC particles with Al powders followed by melting in a vacuum furnace, and varying the residence time. Transmission electron microscopy (TEM), high resolution electron microscopy (HREM) and field emission TEM were employed as the main characterization techniques to study the interfacial reactions occurring between the barrier and the molten aluminium. These studies showed that the SiO2 coating behaves as an active barrier which reacts with the molten Al to form a glassy phase Al-Si-O. This compound underwent partial crystallization during the composite manufacture to form mullite. The formation of an outer crystalline layer, composed mainly of Al2O3, was also detected. Participation of other secondary interface reactions inside the active barrier was also identified by HREM techniques. PMID:11207914

  18. Reuse of dewatered aluminium-coagulated water treatment residual to immobilize phosphorus: Batch and column trials using a condensed phosphate

    Microsoft Academic Search

    A. O. Babatunde; Y. Q. Zhao; Y. Yang; P. Kearney

    2008-01-01

    The aluminium content in dewatered aluminium-coagulated water treatment residual (DAC-WTR) can lead to a high phosphorus (P) removal capacity. Therefore, DAC-WTR has been used as adsorbent\\/soil amendment to remove P in several studies, focusing mostly on orthophosphates (ortho-P). This study is concerned with extending such reuse of DAC-WTR to remove P using a condensed phosphate as the model P source.

  19. Dry wear behaviour and its relation to microstructure of novel 6092 aluminium alloy–Ni 3Al powder metallurgy composite

    Microsoft Academic Search

    Y. Wang; W. M. Rainforth; H. Jones; M. Lieblich

    2001-01-01

    Novel aluminium alloy matrix composites reinforced by 15vol.% Ni3Al intermetallic particles were prepared by a powder metallurgy route. The 6092 aluminium alloy was produced by gas atomisation, followed by blending with Ni3Al particles. Consolidation by extrusion at 515°C, with an extrusion ratio of 30:1, produced a uniform distribution of Ni3Al in the Al alloy matrix. The wear properties of the

  20. Application of aluminium(III) complex with salicylidene- o-aminophenol to the fluorometric determination of nucleic acids

    Microsoft Academic Search

    Yong-Mei Hao; Han-Xi Shen

    2000-01-01

    In buffer medium of hexamethylene tetraamine–HCl at pH 5.9 the aluminium(III) complex with salicylidene-o-aminophenol (SAP) has a fluorescence peak at 508 nm with excitation at 410 nm. When nucleic acid coexists, it reacts with the complex within 8 min at room temperature to produce a non-fluorescent product, resulting in the decrease of fluorescence intensity of the aluminium complex. On basis

  1. Perforation of AA5083-H116 aluminium plates with conical-nose steel projectiles—experimental study

    Microsoft Academic Search

    Tore Børvik; Arild H. Clausen; Odd Sture Hopperstad; Magnus Langseth

    2004-01-01

    The interest regarding use of aluminium alloys in lightweight protective structures is today increasing. Even so, the number of experimental and computational investigations giving detailed information on such problems is still rather limited. In this paper, perforation experiments have been performed on AA5083-H116 aluminium plates with thicknesses varying between 15 and 30mm impacted by 20mm diameter, 98mm long, HRC 53

  2. Optical and structural properties of aluminium oxide thin films prepared by a non-aqueous sol–gel technique

    Microsoft Academic Search

    Nursen Avci; Philippe F. Smet; Johan Lauwaert; Henk Vrielinck; Dirk Poelman

    Clear aluminium oxide sols without precipitation were synthesized via a non-aqueous sol–gel technique using three different\\u000a alcohols (ethanol, isopropanol and n-butyl alcohol) as solvent, aluminium sec-butoxide as a precursor and acetyl acetone as\\u000a a chelating agent. Although all sols could be successfully used to prepare thin films, the most stable one was prepared with\\u000a n-butyl alcohol. Highly transparent, homogenous and

  3. Observations of Schottky and Poole-Frenkel emission in lead phthalocyanine thin films using aluminium injecting electrodes

    Microsoft Academic Search

    T. S. SHAFAI; R. D. GOULD

    1992-01-01

    DC current density-voltage measurements have been performed on vacuum evaporated aluminium-lead phthalocyanine-gold sandwich structures for both electrical polarities. The electrical characteristics differed markedly depending on whether the positive hole-injecting electrode was gold (forward-bias) or aluminium (reverse-bias). An extensive study of such characteristics revealed two distinct regions in the forward-bias characteristics. In the first of these a power-law dependence of current

  4. A Parametric Study of the Low-Impulse Blast Behaviour of Fibre-Metal Laminates Based on Different Aluminium Alloys

    Microsoft Academic Search

    Thuc Vo; Zhongwei Guan; Wesley Cantwell; Graham Schleyer

    2012-01-01

    A parametric study has been undertaken in order to investigate the influence of the properties of the aluminium alloy on the blast response of fibre-metal laminates (FMLs). The finite element (FE) models have been developed and validated using experi-mental data from tests on FMLs based on a 2024-O aluminium alloy and a woven glass-fibre\\/polypropylene composite (GFPP). A vectorized user material

  5. A study of enhanced diffusion during high dose high flux pulsed metal ion implantation into steel and aluminium

    Microsoft Academic Search

    Zhang Tonghe; Ji Chengzhou; Shen Jinghua; Chen Jun

    1992-01-01

    The depth profiles of metal ions implanted into steel and aluminium were measured by Rutherford backscattering (RBS). The ions of Mo, W and Y, produced by a metal vapour vacuum arc ion source (MEVVA) were implanted at an energy range from 25 to 50 keV for doses of (2-5)×1017 cm-2 into H13 steel and aluminium. Beam currents were from 0.5

  6. Simultaneous determination of aluminium and beryllium at the subnanogram per millilitre level by solid-phase derivative spectrophotometry

    Microsoft Academic Search

    Ma Carmen Valencia; Said Boudra; J. Manuel Bosque-Sendra

    1996-01-01

    The applicability of derivative solid-phase spectrophotometry is demonstrated for the resolution of mixtures of aluminium and beryllium with closely overlapping absorption profiles. A spectrophotometric method for the simultaneous determination of beryllium and aluminium based on first-derivative solid-phase spectrophotometry is proposed. Both metal ions were fixed on a dextran-type anion-exchanger gel at pH 4.4, as coloured complexes with Eriochrome Cyanine R

  7. In situ transmission electron microscopy observations delta of dislocation processes in delta-strengthened aluminium-lithium alloys

    Microsoft Academic Search

    Harald Rosner; Wei Liu; Eckhard Nembach

    1999-01-01

    Dislocation processes in delta-strengthened aluminium-rich aluminium-lithium alloys have been studied by transmission electron microscopy; thin foils have been tensile tested in the transmission electron microscope and the configurations of the dislocations and their glide have been observed under full load. The average radii r of the delta precipitates and their volume fractions f have been varied independently: 5 nm <

  8. Evidence for centrophenoxine as a protective drug in aluminium induced behavioral and biochemical alteration in rat brain

    Microsoft Academic Search

    Bimla Nehru; Punita Bhalla; Aarti Garg

    2006-01-01

    Potential use of various nootropic drugs have been a burning area of research on account of various physical and chemical\\u000a insult in brain under different toxicological conditions. One of the nootropic drug Centrophenoxine, also known as an anti-aging\\u000a drug has been exploited in the present experiment under aluminium toxic conditions. Aluminium was administered by oral gavage\\u000a at a dose level

  9. Characterisation of different grades of commercially pure aluminium as prospective galvanic anodes in saline and alkaline battery electrolyte

    Microsoft Academic Search

    I. John Albert; M. Anbu Kulandainathan; M. Ganesan; V. Kapali

    1989-01-01

    The effect of calcium chloride and sodium chloride on the electrochemical properties of various grades of aluminium namely 2s, 3s, 26s and 57s in alkaline citrate solution has been examined by studying the self corrosion, open circuit potential, anodic polarization and anode efficiency. It has been found that among the different grades of aluminium the 57s grade is found to

  10. Galvanostatic electrodeposition of aluminium nano-rods for Li-ion three-dimensional micro-battery current collectors

    Microsoft Academic Search

    Gabriel Oltean; Leif Nyholm; Kristina Edström

    2011-01-01

    Constant current and pulsed current electrodeposition of aluminium nano-rods, for use as three-dimensional (3D) Li-ion micro-battery current collectors, have been studied using an ionic liquid electrolyte (1-ethyl-3-methylimidazolium chloride\\/aluminium chloride) and a template consisting of a commercial alumina membrane. It is shown that the homogeneity of the height of the rods can be improved significantly by inclusion of a short (i.e.

  11. Proppant flowback control additives

    SciTech Connect

    Nguyen, P.D.; Weaver, J.D.; Parker, M.A. [and others

    1996-12-31

    This paper describes the laboratory and field development of thermoplastic film materials used to reduce proppant flowback that can occur after fracturing treatments. The paper provides a summary of flowback mechanism theories and laboratory tests comparing flowback tendency for various types of treating procedures and materials. Some of these materials include angular proppant, proppant/fiber mixtures, and proppant with film strips tested over a wide range of temperature, closure stress, and flow-rate conditions. Field treatment procedures are discussed, and several case histories are presented. All of the methods evaluated were effective in reducing proppant flowback under certain conditions. Heat-shrink film cut into thin slivers proved to provide flowback reduction over broad temperature and closure stress ranges and was found to cause little impairment to fracture conductivity with some dependency on use concentration, temperature, and closure stress. The film materials were more resistant to damage caused by blending and pumping than all other materials evaluated. In addition, proppant packs, including consolidated packs, were significantly more tolerant of large, repeated stress changes. Field results indicate that the use of the heat-shrink film material as a flowback control agent permits more aggressive bean-up procedures following conventional fracturing treatments. Conventional dry-additive metering systems were used to add the film material to the fracturing fluid proppant slurry.

  12. Platelet additive solution - electrolytes.

    PubMed

    Azuma, Hiroshi; Hirayama, Junichi; Akino, Mitsuaki; Ikeda, Hisami

    2011-06-01

    Recent attention to solutions that replace most or all plasma in platelet concentrates, while maintaining satisfactory platelet function, is motivated by the potential of plasma reduction or depletion to mitigate various transfusion-related adverse events. This report considers the electrolytic composition of previously described platelet additive solutions, in order to draw general conclusions about what is required for platelet function and longevity. The optimal concentrations of Na(+) and Cl(-) are 69-115 mM. The presence of both K(+) and Mg(2+) in platelet suspension at nearly physiological concentrations (3-5mM and 1.5-3mM, respectively) is indispensable for good preservation capacity because both electrolytes are required to prevent platelet activation. In contrast to K(+) and Mg(2+), Ca(2+) may not be important because no free Ca(2+) is available in M-sol, which showed excellent platelet preservation capacity at less than 5% plasma concentration. The importance of bicarbonate (approximately 40 mM) can be recognized when the platelets are suspended in additive solution under less than 5% residual plasma concentration. PMID:21498128

  13. Ultrasonic ablation as a novel technique for producing pure aluminium nanoparticles dispersed in different liquids for different applications

    NASA Astrophysics Data System (ADS)

    Ismail, Yasser A. M.; Kishi, Naoki; Soga, Tetsuo

    2015-07-01

    In this paper, we introduce a novel physical method for producing surfactant-free aluminium nanoparticles (Al NPs) by irradiating ultrasonic waves on Al thin films immersed in different liquids used for different applications. We suggest naming this technique “ultrasonic ablation”. Our method has many advantages compared with other chemical and physical methods such as (1) fabrication of Al NPs using low-cost and easy procedures, (2) fabrication of pure Al NPs without any chemical additives, (3) fabrication of Al NPs dispersed in different liquids used for different applications, and (4) fabrication of individual Al NPs without aggregations. We have prepared Al NPs in 1,2-dichlorobenzene, which is used as a solvent for preparing active layer solutions of organic solar cells (OSCs), poly(3,4-ethylenedioxythiophene)-blend-poly(styrene sulfonate) (PEDOT:PSS), which is a representative aqueous solution used as a buffer layer in OSCs, and ethanol, which is a representative polar solvent used for different applications. Scanning electron microscopy (SEM) and optical absorption techniques have verified the fabrication of individual and surfactant-free Al NPs dispersed in different liquids that can be safely used in different applications.

  14. Surface modification of aluminium alloys using hybrid treatment techniques

    NASA Astrophysics Data System (ADS)

    Petrov, P.

    2012-03-01

    The application of electron and laser beams to the modification of metal and alloys opens up new possibilities of improving the materials properties. In recent years, the studies aimed at developing new materials have brought about the development of hybrid treatment techniques. These techniques perform an additional alloying in the zone treated, which has a substantial effect on the physical and mechanical properties of the materials processed. In this work we report results on the microstructural changes and mechanical properties of heat-treated AlSi12CuNiMg alloys resulting from additional alloying with Fe, Co, Ni, Cr by hybrid electron-beam techniques. It is established that the mechanical properties of Al-Si alloys can be improved by means of additional alloying with Fe, Co, Ni, Cr by hybrid electron-beam techniques. The specimens' properties practically do not change after heat-treatment (aging) for up to 200 hours at 250 °C.

  15. New addition curing polyimides

    NASA Technical Reports Server (NTRS)

    Frimer, Aryeh A.; Cavano, Paul

    1991-01-01

    In an attempt to improve the thermal-oxidative stability (TOS) of PMR-type polymers, the use of 1,4-phenylenebis (phenylmaleic anhydride) PPMA, was evaluated. Two series of nadic end-capped addition curing polyimides were prepared by imidizing PPMA with either 4,4'-methylene dianiline or p-phenylenediamine. The first resulted in improved solubility and increased resin flow while the latter yielded a compression molded neat resin sample with a T(sub g) of 408 C, close to 70 C higher than PME-15. The performance of these materials in long term weight loss studies was below that of PMR-15, independent of post-cure conditions. These results can be rationalized in terms of the thermal lability of the pendant phenyl groups and the incomplete imidization of the sterically congested PPMA. The preparation of model compounds as well as future research directions are discussed.

  16. Sewage sludge additive

    NASA Technical Reports Server (NTRS)

    Kalvinskas, J. J.; Mueller, W. A.; Ingham, J. D. (inventors)

    1980-01-01

    The additive is for a raw sewage treatment process of the type where settling tanks are used for the purpose of permitting the suspended matter in the raw sewage to be settled as well as to permit adsorption of the dissolved contaminants in the water of the sewage. The sludge, which settles down to the bottom of the settling tank is extracted, pyrolyzed and activated to form activated carbon and ash which is mixed with the sewage prior to its introduction into the settling tank. The sludge does not provide all of the activated carbon and ash required for adequate treatment of the raw sewage. It is necessary to add carbon to the process and instead of expensive commercial carbon, coal is used to provide the carbon supplement.

  17. Quaternary deposit control additives

    SciTech Connect

    Campbell, C.B.

    1986-01-14

    This patent describes a fuel's composition consisting of a major portion of hydrocarbons, which boils in the gasoline range, and from 30-10,000 ppm of a quaternized polyoxyalkylene amine salt of molecular weight 500-2500. This polyoxyalkylene moiety is characterized as consisting of 1-30 oxyalkylene units with 2-4 carbon atoms apiece. The aforementioned amine moiety consists of 1-2 amine nitrogen atoms and from about 2-40 carbon atoms. In addition, the fuel is characterized as containing a connecting moiety linking the polyoxyalkylene moiety and the amine moiety and within which the anion of the quaternized polyoxylakylene amine salts is composed of either chloride, bromide, or iodide.

  18. Performance Boosting Additive

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Mainstream Engineering Corporation was awarded Phase I and Phase II contracts from Goddard Space Flight Center's Small Business Innovation Research (SBIR) program in early 1990. With support from the SBIR program, Mainstream Engineering Corporation has developed a unique low cost additive, QwikBoost (TM), that increases the performance of air conditioners, heat pumps, refrigerators, and freezers. Because of the energy and environmental benefits of QwikBoost, Mainstream received the Tibbetts Award at a White House Ceremony on October 16, 1997. QwikBoost was introduced at the 1998 International Air Conditioning, Heating, and Refrigeration Exposition. QwikBoost is packaged in a handy 3-ounce can (pressurized with R-134a) and will be available for automotive air conditioning systems in summer 1998.

  19. Microstructure heterogeneity after the ECAP process and its influence on recrystallization in aluminium

    SciTech Connect

    Wronski, S., E-mail: wronski@fis.agh.edu.pl [Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Kraków (Poland); Tarasiuk, J., E-mail: tarasiuk@ftj.agh.edu.pl [Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Kraków (Poland); Bacroix, B., E-mail: brigitte.bacroix@univ-paris13.fr [LPMTM-CNRS, Université Paris XIII, 99, av. J.B. Clement, 93 430 Villetaneuse (France); Wierzbanowski, K., E-mail: wierzban@ftj.agh.edu.pl [Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Kraków (Poland); Paul, H., E-mail: nmpaul@imim-pan.krakow.pl [Institute of Metallurgy and Materials Science of Polish Academy of Sciences, Reymonta Street 25, 30-059 Kraków (Poland)

    2013-04-15

    The main purpose of the present work is to describe the qualitative and quantitative behaviours of aluminium during high strain plastic deformation and the effect of deformation on the subsequent recrystallization process. An Electron Backscatter Diffraction analysis of aluminium after the Equal channel angular pressing (ECAP) and recrystallization process is presented. In order to do this, several topological maps are measured for samples processed by 4 and 8 passes and recrystallized. The processing was conducted with route C. For all samples, distributions of grain size, misorientation, image quality factor (IQ) and texture were preceded and then analysed in some detail. - Highlights: ? Describe the microstructure fragmentation in aluminum. ? High strain plastic deformation and effect of deformation on recrystallization. ? The microstructure fragmentation and its influence on recrystallization. ? Image quality factor and misorientation characteristics are examined using EBSD.

  20. Comparison of nickel silicide and aluminium ohmic contact metallizations for low-temperature quantum transport measurements

    PubMed Central

    2011-01-01

    We examine nickel silicide as a viable ohmic contact metallization for low-temperature, low-magnetic-field transport measurements of atomic-scale devices in silicon. In particular, we compare a nickel silicide metallization with aluminium, a common ohmic contact for silicon devices. Nickel silicide can be formed at the low temperatures (<400°C) required for maintaining atomic precision placement in donor-based devices, and it avoids the complications found with aluminium contacts which become superconducting at cryogenic measurement temperatures. Importantly, we show that the use of nickel silicide as an ohmic contact at low temperatures does not affect the thermal equilibration of carriers nor contribute to hysteresis in a magnetic field. PMID:21968083

  1. Unequivocal identification of intracellular aluminium adjuvant in a monocytic THP-1 cell line

    PubMed Central

    Mold, Matthew; Eriksson, Håkan; Siesjö, Peter; Darabi, Anna; Shardlow, Emma; Exley, Christopher

    2014-01-01

    Aluminium-based adjuvants (ABA) are the predominant adjuvants used in human vaccinations. While a consensus is yet to be reached on the aetiology of the biological activities of ABA several studies have identified shape, crystallinity and size as critical factors affecting their adjuvanticity. In spite of recent advances, the fate of ABA following their administration remains unclear. Few if any studies have demonstrated the unequivocal presence of intracellular ABA. Herein we demonstrate for the first time the unequivocal identification of ABA within a monocytic T helper 1 (THP-1) cell line, using lumogallion as a fluorescent molecular probe for aluminium. Use of these new methods revealed that particulate ABA was only found in the cell cytoplasm. Transmission electron microscopy revealed that ABA were contained within vesicle-like structures of approximately 0.5–1??m in diameter. PMID:25190321

  2. Finite Element Analysis of Warpage in Laminated Aluminium Alloy Plates for Machining of Primary Aeronautic Parts

    SciTech Connect

    Reis, A. C.; Moreira Filho, L. A. [ITA - Aeronautic Technological Institute, IEM, Praca Mal. Eduardo Gomes, 50 - Vila das Acacias - S. J. Campos, CEP 1228-900 (Brazil); Menezes, M. A. [ITA - Aeronautic Technological Institute, IEM, Praca Mal. Eduardo Gomes, 50 - Vila das Acacias - S. J. Campos, CEP 1228-900 (Brazil); UNESP - Sao Paulo State University, Ilha Solteira Engineering Faculty, DEM, Av. Brasil, 56 - Centro - Ilha Solteira - SP, CEP 15385-000 (Brazil)

    2007-04-07

    The aim of this paper consists in presenting a method of simulating the warpage in 7xxx series aluminium alloy plates. To perform this simulation finite element software MSC.Patran and MSC.Marc were used. Another result of this analysis will be the influence on material residual stresses induced on the raw material during the rolling process upon the warpage of primary aeronautic parts, fabricated through machining (milling) at Embraer. The method used to determinate the aluminium plate residual stress was Layer Removal Test. The numerical algorithm Modified Flavenot Method was used to convert layer removal and beam deflection in stress level. With such information about the level and profile of residual stresses become possible, during the step that anticipate the manufacturing to incorporate these values in the finite-element approach for modelling warpage parts. Based on that warpage parameter surely the products are manufactured with low relative vulnerability propitiating competitiveness and price.

  3. Duty cycle and modulation effects in aluminium alloy welding with high power Nd-YAG laser

    SciTech Connect

    Kathuria, Y.P.; Tsuboi, Akihiko [Laser X Co. Ltd., Chiryu, Aichi (Japan)

    1996-12-31

    The demand for the light aluminum vehicles using aluminium alloys will be strengthened in the future. The development of aluminium alloys, e.g., Al-Mg and Al-Zn-Mg alloys is being actively considered and have resulted good results. In view of this, processing of Al-alloys, specially its weldability has been of much importance. Here, the modulation and duty cycle effects on Al-alloy welding with high power Nd-YAG laser are investigated. Microstructural characterization of the low and high duty welds with wave modulation identified the differences in the weld morphology. Welding depth, undercut and strength of fusion zone are discussed as a function of the processing parameters.

  4. Investigation of femtosecond collisional ionization rates in a solid-density aluminium plasma

    NASA Astrophysics Data System (ADS)

    Vinko, S. M.; Ciricosta, O.; Preston, T. R.; Rackstraw, D. S.; Brown, C. R. D.; Burian, T.; Chalupský, J.; Cho, B. I.; Chung, H.-K.; Engelhorn, K.; Falcone, R. W.; Fiokovinini, R.; Hájková, V.; Heimann, P. A.; Juha, L.; Lee, H. J.; Lee, R. W.; Messerschmidt, M.; Nagler, B.; Schlotter, W.; Turner, J. J.; Vysin, L.; Zastrau, U.; Wark, J. S.

    2015-03-01

    The rate at which atoms and ions within a plasma are further ionized by collisions with the free electrons is a fundamental parameter that dictates the dynamics of plasma systems at intermediate and high densities. While collision rates are well known experimentally in a few dilute systems, similar measurements for nonideal plasmas at densities approaching or exceeding those of solids remain elusive. Here we describe a spectroscopic method to study collision rates in solid-density aluminium plasmas created and diagnosed using the Linac Coherent light Source free-electron X-ray laser, tuned to specific interaction pathways around the absorption edges of ionic charge states. We estimate the rate of collisional ionization in solid-density aluminium plasmas at temperatures ~30?eV to be several times higher than that predicted by standard semiempirical models.

  5. Fabrication of Nano-Composite Surface Layers on Aluminium Employing Friction Stir Processing Technique

    SciTech Connect

    Bozorg, S. F. K.; Zarghani, A. S.; Zarei-Hanzaki, A. [School of Metallurgy and Materials Engineering, Faculty of Engineering, University of Tehran, Tehran, P.O. Box: 14395-553 (Iran, Islamic Republic of)

    2010-03-11

    Al/Al{sub 2}O{sub 3} nano-composite surface layer was fabricated via friction stir processing technique. Commercial AA6082 aluminium alloy extruded bar and nanometric Al{sub 2}O{sub 3} powder were subjected to friction stir processing at a substrate travel speed of 80 mm/min and a tool rotation speed of 1000 rpm using a hardened H-13 tool steel. The grain structure and reinforcement particles were investigated by using optical and scanning electron microscopy. Results show that Al{sub 2}O{sub 3} particles can be more uniformly dispread in aluminium substrate by increasing the number of processing passes. Also, hardness enhancement of the nano-composite surface layer was found. This is attributed to uniform dispersion of Al{sub 2}O{sub 3} particles.

  6. Development of Aluminium Vacuum Chambers for the LHC Experiments at CERN

    E-print Network

    Gallilee, M; Costa-Pinto, P; Lepeule, P; Perez-Espinos, J; Marques Antunes Ferreira, L; Prever-Loiri, L; Sapountzis, A

    2014-01-01

    Beam losses may cause activation of vacuum chamber walls, in particular those of the Large Hadron Collider (LHC) experiments. For the High Luminosity (HL-LHC), the activation of such vacuum chambers will increase. It is therefore necessary to use a vacuum chamber material which interacts less with the circulating beam. While beryllium is reserved for the collision point, a good compromise between cost, availability and transparency is obtained with aluminium alloys; such materials are a preferred choice with respect to austenitic stainless steel. Manufacturing a thin-wall aluminium vacuum chamber presents several challenges as the material grade needs to be machinable, weldable, leak-tight for small thicknesses, and able to withstand heating to 250°C for extended periods of time. This paper presents some of the technical challenges during the manufacture of these vacuum chambers and the methods for overcoming production difficulties, including surface treatments and Non-Evaporable Getter (NEG) thin-film coat...

  7. Laser Surface Pre-treatment of Aluminium for Hybrid Joints with Glass Fibre Reinforced Thermoplastics

    NASA Astrophysics Data System (ADS)

    Heckert, André; Zaeh, Michael F.

    Lightweight construction is a major trend in the automotive industry. Theconnection of fibre reinforced plastics with aluminium is consequently seen as promising prospect. In this regard, thermal joining can be applied for bonding of such hybrid joints. But in order to create a load bearing metal plastic joint, the surface of the metal has to be pre-treated. Recent research has shown that with laser surface pre-treatment high joint strengths are obtained. Yet there are a variety of laser sources and manufacturable surface topographies with structure sizes ranging from macroscopic to nanoscopic profiles. Within this work,macroscopic, microscopic and nanoscopic laser processed structures are created on aluminium and consequently joined to glass fibre reinforced thermoplastics of different fibre length and fibre content. High shear tensile strengths of up to 42 N/mm2 were obtained depending on the allocated material and the surface pre-treatment.

  8. Combined Laser Beam Welding and Brazing Process for Aluminium Titanium Hybrid Structures

    NASA Astrophysics Data System (ADS)

    Möller, F.; Grden, M.; Thomy, C.; Vollertsen, F.

    The current state of the art in light-weight construction is - for the case of aircraft structures - the use of either aluminium or titanium. Whereas aluminium is light-weight and less expensive, titanium offers superior corrosion properties at higher cost. In order to combine the advantages of both materials, a hybrid Ti-Al structure is proposed for e.g. seat-track application. In this paper, an overview of the results from this research work and the accompanying thermo-mechanical simulations will be reported and discussed. On the basis of the development of an appropriate system technology, the process development will be described, focusing on the main influencing parameters of the process on joint properties.

  9. Aluminium causes variable responses in actin filament cytoskeleton of the root tip cells of Triticum turgidum

    Microsoft Academic Search

    G. Frantzios; B. Galatis; P. Apostolakos

    2005-01-01

    Summary.  The effects of aluminium on the actin filament (AF) cytoskeleton of Triticum turgidum meristematic root tip cells were examined. In short treatments (up to 2 h) with 50–1000 ?M AlCl36H2O, interphase cells displayed numerous AFs arrayed in thick bundles that lined the plasmalemma and traversed the endoplasm\\u000a in different directions. Measurements using digital image analysis and assessment of the overall

  10. Robust parameter design and multi-objective optimization of laser beam cutting for aluminium alloy sheet

    Microsoft Academic Search

    Avanish Kumar Dubey; Vinod Yadava

    2008-01-01

    The application of laser beam for precise cutting of sheet metals, in general, and reflective sheet metals, like aluminium,\\u000a in particular, has become of interest in the recent past. The optimum choice of the cutting parameters is essential for the\\u000a economic and efficient cutting of difficult to cut materials with laser beams. In this paper, a robust design and quality

  11. Manufacture and evaluation of hoop-wound fibre-reinforced aluminium alloy tube

    Microsoft Academic Search

    A. S. Chen; V. D. Scott; R. S. Bushby

    1998-01-01

    A composite tube, consisting of aluminium-magnesium-silicon alloy (6061) reinforced with hoop-wound alumina-based fibres, has been manufactured by using the method of liquid metal infiltration. The composite was well-consolidated with a good bond between the fibres and the matrix, as evinced by the close similarity between measured values of modulus and ‘rule of mixtures’ calculations. Although some matrix magnesium was absorbed

  12. Phosphorus recovery as AlPO 4 from beneficially reused aluminium sludge arising from water treatment

    Microsoft Academic Search

    X. H. Zhao; Y. Q. Zhao; P. Kearney

    2012-01-01

    The purpose of this study was to develop an efficient and, possibly, a practically operated methodology to recover phosphorus (P) from P-saturated dewatered aluminium sludge cakes (DASC) after the DASC have been beneficially reused as constructed wetlands substrate for P-rich wastewater treatment. A three-step procedure of 1) P extraction by H 2SO 4, 2) decolorization of extraction leachate via H

  13. Thermal degradation of blends of phenyl methacrylate–styrene copolymers with aluminium ethoxide

    Microsoft Academic Search

    Shagufta Zulfiqar; Khalid Masud; Q Ameer

    2002-01-01

    The thermal behaviour of phenyl methacrylate–styrene (PMA–ST) copolymers was studied in the presence of aluminium ethoxide [Al(OC2H5)3]. The blends were investigated in an inert atmosphere using thermogravimetry–differential thermogravimetry (TG–DTG) and under vacuum using thermal volatilisation analysis (TVA). The condensable volatile degradation products from the TVA experiments were separated by sub-ambient TVA and characterized by IR spectroscopy and gas chromatography–mass spectrometry

  14. Spurenanalytik von Aluminium und Eisen mittels Ionen-Chromatographie und post-chromatographischer Umsetzung

    Microsoft Academic Search

    Da-Ren Yan; Georg Schwedt

    1985-01-01

    Various post-chromatographic derivatisations based on the use of PAR, PAR-ZnEDTA, Chrome Azurol S, Eriochrome Cyanine R were systematically investigated for a sensitive trace analysis of aluminium and iron (II\\/III) cations. By the combination of a cation exchanger with low capacity (Dionex CS-2), sulfosalicyclic acid\\/ethylenediamine pH 5 as eluent as well as the reagent mixture Chrome Azurol S\\/cetyltrimethyl-ammonium bromide\\/Triton X-100 (measurements

  15. Simultaneous determination of iron and aluminium by differential kinetic spectrophotometric method and chemometrics

    Microsoft Academic Search

    Yongnian Ni; Chunfang Huang; Serge Kokot

    2007-01-01

    A differential kinetic spectrophotometric method was researched and developed for the simultaneous determination of iron and aluminium in food samples. It was based on the direct reaction kinetics and spectrophotometry of these two metal ions with Chrome Azurol S (CAS) in ethylenediamine–hydrochloric acid buffer (pH 6.3). The results were interpreted with the use of chemometrics. The kinetic runs and the

  16. Simulation of hollow shaped charge jet impacts onto aluminium whipple bumpers at 11 km\\/s

    Microsoft Academic Search

    Emma A. Taylor

    2001-01-01

    The computational technique of Smoothed Particle Hydrodynamics (as implemented in the hydrocodes AUTODYN-2D and AUTODYN-3D) has been used to simulate the impact of hollow shaped charge jet projectiles onto stuffed Whipple bumper shielding. Due to limited availability of material models, the interim Nextel\\/Kevlar-Epoxy bumper was modelled as an equivalent thickness of aluminium. Stuffed Whipple bumper shields are used for meteoroid

  17. Disulfide stress-induced aluminium toxicity: molecular insights through genome-wide screening of Saccharomyces cerevisiae.

    PubMed

    Tun, Nay M; O'Doherty, Patrick J; Perrone, Gabriel G; Bailey, Trevor D; Kersaitis, Cindy; Wu, Ming J

    2013-08-01

    Formation of non-native disulfide bonds within or between proteins can lead to protein misfolding and disruption to cellular metabolism. Such a process is defined as disulfide stress. A marked effect of disulfide stress in cells is the elevated accumulation of the intracellular aluminium ion (Al(3+)) accompanied by increased cytotoxicity. To gain an in-depth understanding of the underlying molecular mechanism for disulfide stress-induced aluminium toxicity, the complete set of Saccharomyces cerevisiae deletion mutants (5047) was screened in this study simultaneously with a combination of the two stressors, diamide and Al(3+). The combined treatment of a benign concentration of diamide (0.8 mM) with a sublethal concentration of aluminium sulfate (0.4 mM) revealed 494 sensitive deletion mutants, distinct from those found when either of the single stressors (0.8 mM diamide or 0.4 mM aluminium sulfate) was used. Hierarchical clustering and functional analyses of the 494 mutants sensitive to the dual stressors indicated a significant enrichment in the genes involved in cell wall homeostasis, signaling cascades, secretory transport machinery and detoxification. The results highlight the process of maintaining cell wall integrity as the central response to the combined exposure of diamide and Al(3+), which is mediated by the signaling pathways and transcription activation via Rlm1p and Swi6p for biosynthesis of the essential cell wall components such as glucan and chitin. Sensitivity of mutants associated with endoplasmic reticulum (ER), vesicle and vacuole functions demonstrates that secretory machinery is essential for surviving the stress conditions, probably due to their roles in transporting polysaccharides to the cell wall and detoxification of accumulated Al(3+). Finally, the phenotype of 100 previously uncharacterized genes against the dual stressors will contribute to their eventual functional annotation. PMID:23832094

  18. A new testing machine to determine the behaviour of aluminium granulate under combined pressure and shear

    Microsoft Academic Search

    Fredrik Widerøe; Torgeir Welo; Harald Vestøl

    To reduce the environmental impact and increase the yield from conventional aluminium recycling processes, a direct continuous\\u000a extrusion method of shredded scrap is being developed. The innovative method is a process where a rotating screw generates\\u000a the extrusion pressure, introducing rotation to the scrap compacting and extruding in one single operation. The objective\\u000a of this paper is to present a

  19. Arsenic removal during conventional aluminium-based drinking-water treatment

    Microsoft Academic Search

    Jan Gregor

    2001-01-01

    The changing forms and concentrations of arsenic through aluminium-based coagulation treatment processes were tracked for three drinking-water treatment plants. This has provided direct evidence of where and how arsenic is removed. In general, soluble As(V) is converted to particulate As(V) by adsorption during rapid mixing, and is removed along with naturally occurring particulate arsenic predominantly by clarification. Soluble As(III) tracks

  20. Changes in the microbial community in a forest soil amended with aluminium in situ

    Microsoft Academic Search

    Erik J. Joner; Toril D. Eldhuset; Holger Lange; Åsa Frostegård

    2005-01-01

    Considerable knowledge exists about the effect of aluminium (Al) on root vitality, but whether elevated levels of Al affect\\u000a soil microorganisms is largely unknown. We thus compared soils from Al-treated and control plots of a field experiment with\\u000a respect to microbial and chemical parameters, as well as root growth and vitality. The field experiment was established in\\u000a a 50-year-old Norway

  1. Response of aluminium-infiltrated boron carbide cermets to shock wave loading

    Microsoft Academic Search

    W. R. Blumenthal; G. T. GRAY II; T. N. Claytor

    1994-01-01

    Shock-recovery and shock-spallation experiments were performed on two compositions of aluminium-infiltrated B4C cermets as a function of shock pressure. Sixty-five per cent volume B4C-Al cermets were recovered largely intact after shock loading up to pressures of ca. 12 GPa which permitted a critical study of the microstructural changes produced by the shock. Significantly, shock loading to between 12 and 13

  2. Energy absorption behavior of closed-cell aluminium foam under drop mass impact tests

    Microsoft Academic Search

    Fujun Yang; Siyuan Ni; Xiaoyuan He; Deping He

    2008-01-01

    Quasi-static axial compression and drop mass impact tests were performed to study the energy absorption behaviour of the closed-cell aluminium foam. Digital image analysis was firstly used to characterize the surface's structure of individual cells and aggregates of cells. The cell structure characterizations performed using the best-fit ellipse equivalent diameter for the individual cells, which included measurement of the size

  3. Numerical simulation of drop weight impact behaviour of closed cell aluminium foam

    Microsoft Academic Search

    R. Rajendran; A. Moorthi; S. Basu

    2009-01-01

    Numerical simulation is carried out using ANSYS\\/LS-DYNA for closed cell aluminium foam undergoing axial impact due to free fall of a drop hammer. Quasi-static axial crushing tests carried out on foams of three different densities were applied to derive the material properties. Mesh refinement results showed that coarse mesh was sufficient to predict the results accurately. Simulation was validated with

  4. GBT local and global buckling analysis of aluminium and stainless steel columns

    Microsoft Academic Search

    Rodrigo Gonçalves; Dinar Camotim

    2004-01-01

    A non-linear elastic Generalised Beam Theory (GBT) is formulated and used to investigate the buckling behaviour of aluminium and stainless steel thin-walled columns. The modifications that must be incorporated in the conventional GBT, in order to handle the material non-linearity, are addressed and particular attention is paid to the need to define the stability problem in terms of instantaneous elastic

  5. STRUCTURAL TRANSITION OF AMMONIUM ALUMINIUM ALUMS STUDIED BY E.P.R.

    E-print Network

    Paris-Sud XI, Université de

    795 STRUCTURAL TRANSITION OF AMMONIUM ALUMINIUM ALUMS STUDIED BY E.P.R. R. CHICAULT and R. BUISSON alums A1NH4 and A1ND4 are reported. These alums undergo a phase transition at respectively 60 K and 56 K changes. Alums have general formulae (S04)2 TM, 12 H20, where T is a trivalent metal and M a monovalent

  6. A sensitive, rapid and inexpensive method to assess aluminium(III) ions in technetium eluates.

    PubMed

    Buroni, Federica E; Lodola, Lorenzo; Persico, Marco G; Aprile, Carlo

    2014-07-01

    The aim of the study was to validate a semiquantitative analytical method to identify the aluminium(III) [Al(III)] concentration in 99Mo/99mTc generator eluates to check the European Pharmacopoeia (Ph. Eur.) requirement (<5 ?g/ml). Three different solutions measuring 20 ml - 0.2% 1,10-phenanthroline, 0.05% chrome azurol S and 20% hexamethylenetetramine - were prepared. A cellulose filter paper was subsequently immersed in them, dried overnight at room temperature and cut into rectangles. A volume of 5 ?l of first eluates of various 99Mo/99mTc generators was placed onto a reagent paper and the spot colour was compared with a standard aluminium solutions scale (0-100 ?g/ml). A cyan/magenta/yellow/key (CMYK) model analysis was adapted to quantify the intensity of colour on the paper, and the presence of aluminium in the eluates was detected by a spectrophotometer. Small changes in standard solution pH (4.1-5.2) and chrome azurol S concentration did not affect the analysis. The cyan channel image analysis was proportional to the Al3+ solution concentration (y=25 019x+1489, R2=0.9554 within 2.5-8 ?g/ml). The detection limit for aluminium by the visual test method is about 1 ?g/ml, and fading is absent. The cyan channel image analysis method is independent of the observer and is applicable for the evaluation of the chemical purity of 99Mo/99mTc generator eluates. Our colorimetric 'spot test' is advantageous for the visual evaluation of Al pertechnetate concentrations as required by Ph. Eur. showing a sensitivity and a limit of detection superior to that of commercially available spot systems. PMID:24681768

  7. Hydrogenated aluminium-doped zinc oxide semiconductor thin films for polymeric light-emitting diodes

    Microsoft Academic Search

    X. T. Hao; F. R. Zhu; K. S. Ong; L. W. Tan

    2006-01-01

    Highly conducting transparent thin films of aluminium(Al)-doped zinc oxide (ZnO:Al) were deposited by a radio frequency magnetron-sputtering technique using an argon and hydrogen gas mixture at room temperature. Hydrogen serves as a shallow donor and plays a critical role in improving the Al doping efficiency to enhance the conductivity of thin films. The effect of hydrogen partial pressure on the

  8. The structure of amorphous aluminium phosphate by radial distribution functions derived from X-ray diffraction

    Microsoft Academic Search

    G. D. Wignall; R. N. Rothon; G. W. Longman; G. R. Woodward

    1977-01-01

    An investigation of the molecular structure of amorphous aluminium phosphate, prepared from a recently discovered complex (AlPO4 · HCl · 4C2H5OH), has been carried out using radial distribution function (RDF) techniques. Studies were made on two samples, one prepared by decomposing the solid complex and the other from powder produced by evaporating to dryness a solution of the complex in

  9. Fatigue strength of welded joints in 6N01 aluminium alloy extrusions

    Microsoft Academic Search

    K. Matsuoka; S. Chiaki; T. Uemura; K. Kamata

    1994-01-01

    In this paper, the fatigue strength of welded joints in 6N01 aluminium alloy extrusions is discussed. Low copper content (?0.02%) alloys were chosen, considering corrosion resistance in sea water. Two series of specimens were prepared. One had two longitudinal stiffeners welded on both sides of the main plate (L?TYPE), and the other a non?load carrying fillet welded cruciform joint (T?TYPE).

  10. Fatigue crack growth behaviour of A5083 series aluminium alloys and their welded joints

    Microsoft Academic Search

    Koji Gotoh; Koji Murakami; Yasuo Noda

    We investigated the difference in fatigue behaviour between the aluminium alloys A5083-O and A5083-H321, which are used as\\u000a structural components in ships and high speed craft. We obtained S–N curves for the base materials and the welded joints made\\u000a of A5083-O. The relationships between the fatigue crack propagation rates and the stress intensity factor ranges ?K, ?K\\u000a eff and ?K

  11. Influence of zinc on calcium-dependent signal transduction pathways during aluminium-induced neurodegeneration.

    PubMed

    Singla, Neha; Dhawan, D K

    2014-10-01

    Metals perform important functions in the normal physiological system, and alterations in their levels may lead to a number of diseases. Aluminium (Al) has been implicated as a major risk factor, which is linked to several neurodegenerative diseases including Alzheimer's disease and Parkinson's disease. On the other hand, zinc (Zn) is considered as a neuromodulator and an essential dietary element that regulates a number of biological activities in our body. The aim of the present study was to investigate the effects of Zn supplementation, if any, in ameliorating the changes induced by Al on calcium signalling pathway. Male Sprague Dawley rats weighing 140-160 g were divided into four different groups viz.: normal control, aluminium treated (100 mg/kg b.wt./day via oral gavage), zinc treated (227 mg/l in drinking water) and combined aluminium and zinc treated. All the treatments were carried out for a total duration of 8 weeks. Al treatment decreased the Ca(2+) ATPase activity whereas increased the levels of 3', 5'-cyclic adenosine monophosphate, intracellular calcium and total calcium content in both the cerebrum and cerebellum, which, however, were modulated upon Zn supplementation. Al treatment exhibited a significant elevation in the protein expressions of phospholipase C, inositol triphosphate and protein kinase A but decreased the expression of protein kinase C, which, however, was reversed upon Zn co-treatment. Al treatment also revealed alterations in neurohistoarchitecture in the form of calcium deposits, which were improved upon zinc co-administration. The present study, therefore, suggests that zinc regulates the intracellular calcium signalling pathway during aluminium-induced neurodegeneration. PMID:24500000

  12. Application of Taguchi method for the multi-objective optimization of aluminium foam manufacturing parameters

    Microsoft Academic Search

    Rossella Surace; Luigi Alberto Ciro De Filippis; Antonio Domenico Ludovico; Giancarlo Boghetich

    2010-01-01

    In this study the Taguchi method is used to find the optimal process parameters for aluminium foam manufacturing. Porous metals\\u000a are the unique materials used for light weight structural components, for filters and electrodes and for shock or sound absorbing\\u000a products. Recently, interesting foaming technology developments have proposed metallic foams as a valid commercial chance.\\u000a Metallic foam manufacturing techniques include

  13. Fractal dimension values of cerebral and cerebellar activity in rats loaded with aluminium

    Microsoft Academic Search

    Goran Kekovic; Milka Culic; Ljiljana Martac; Gordana Stojadinovic; Ivan Capo; Dusan Lalosevic; Slobodan Sekulic

    2010-01-01

    Aluminium interferes with a variety of cellular metabolic processes in the mammalian nervous system and its intake might increase\\u000a a risk of developing Alzheimer’s disease (AD). While cerebral involvement even at the early stages of intoxication is well\\u000a known, the role of cerebellum is underestimated. Our aim was to investigate cerebral and cerebellar electrocortical activity\\u000a in adult male rats exposed

  14. Synthesis and photophysical properties of aluminium tris-(4-morpholine-8-hydroxyquinoline).

    PubMed

    Omar, Walaa A E

    2013-11-01

    Aluminium tris(4-morpholinyl-8-hydroxyquinoline) has been synthesized and characterized. The photoluminescence measurements showed that the new derivative is blue shifted and has relative photoluminescence quantum yield two times higher compared to the pristine Al tris(8-hydroxyquinoline). Deferential scanning colorimetric studies revealed that the newly synthesized Alq3 derivative in this work is amorphous material with the highest transition glass temperature value among the reported amorphous Alq3 derivatives. PMID:25685461

  15. Dynamic mechanical response and thermal expansion of ceramic particle reinforced aluminium 6061 matrix composites

    Microsoft Academic Search

    Rajendra U. Vaidya; Shihong G. Song; Anna K. Zurek

    1994-01-01

    The mechanical response of silicon carbide (SiC) particle and boron carbide (B4C) particle reinforced aluminium 6061 alloy was studied under quasi-static and dynamic loading conditions, using an Instron universal testing machine and split Hopkinson pressure bar respectively. The stiffness and yield strength of the B4C and SiC particle composites were significantly enhanced as compared to the unreinforced alloy. The strain

  16. Aluminium-induced crystallisation of silicon on glass for thin-film solar cells

    Microsoft Academic Search

    Oliver Nast; Stephan Brehme; Stephen Pritchard; Armin G Aberle; Stuart R Wenham

    2001-01-01

    Aluminium-induced crystallisation of amorphous silicon is studied for the formation of continuous polycrystalline silicon thin-films on low-temperature glass substrates. It is shown to be a promising alternative to laser crystallisation and solid-phase crystallisation. Silicon grain sizes of larger than 10?m are achieved at temperatures of around 475°C within annealing times as short as 1h. The Al doping concentration of the

  17. Bioavailability and Toxicity of Freshly Neutralized Aluminium to the Freshwater Crayfish Pacifastacus leniusculus

    Microsoft Academic Search

    E. Alexopoulos; C. R. McCrohan; J. J. Powell; R. Jugdaohsingh; K. N. White

    2003-01-01

    Freshly neutralized aluminium (Al) is toxic to a variety of freshwater organisms despite its insolubility at circumneutral pH. Insoluble Al acts exogenously—for example, on the fish gill—thereby impairing respiratory function, and endogenously in grazing and filter-feeding invertebrates following ingestion during drinking and feeding. This paper examines the bioavailability and behavioral toxicity of freshly neutralized Al to the freshwater crayfish Pacifastacus

  18. An investigation on the bearing test procedure for fibre-reinforced aluminium laminates

    Microsoft Academic Search

    H. F. Wu; L. L. Wu; W. J. Slagter

    1994-01-01

    Excellent fatigue, static strength and damage tolerance characteristics together with low density make fibre-reinforced aluminium laminates a prime candidate sheet material for application in fatigue- and fracture-critical aircraft structures. Their use requires that mechanical property design allowables be established for incorporation in design handbooks (e.g. MIL-HDBK-5). An experimental programme based on statistical design was conducted to establish a meaningful test

  19. Exergy analysis and efficiency evaluation for an aluminium melting furnace in a die casting plant

    Microsoft Academic Search

    Dennis Lee

    2003-01-01

    An aluminium melting furnace efficiency in a die casting plant was investigated using energy and exergy methods. Energy efficiency and exergy efficiency values were evaluated for the natural gas-fired furnace, and the efficiency improvement was analyzed before and after two new regenerative burners were installed on the furnace.\\u000aThe research analyzed and compared the environmental impacts attributable to the melting

  20. Numerical and experimental study of dry cutting for an aeronautic aluminium alloy (A2024-T351)

    Microsoft Academic Search

    Tarek Mabrouki; François Girardin; Muhammad Asad; Jean-François Rigal

    2008-01-01

    In the present contribution, numerical and experimental methodologies concerning orthogonal cutting are proposed in order to study the dry cutting of an aeronautic aluminium alloy (A2024-T351). The global aim concerns the comprehension of physical phenomena accompanying chip formation according to cutting velocity variation.For the numerical model, material behaviour and its failure criterion are based on the Johnson–Cook law. The model

  1. Effect of aging time and temperature on intergranular corrosion of aluminium alloys

    Microsoft Academic Search

    Fuad M. Khoshnaw; Ramadhan H. Gardi

    2006-01-01

    Purpose – Two types of aluminium alloys, 2024-T3 and 7075-T6, having been selected, this study aims to investigate the effect of metallurgical aspects on intergranular corrosion. Design\\/methodology\\/approach – To determine and evaluate the metallurgical effects of heat treatments on corrosion behaviour of these alloys, G67 ASTM test was selected. Findings – The results showed that with increasing the aging time

  2. Modeling of residual stress relaxation of fatigue in 2024-T351 aluminium alloy

    Microsoft Academic Search

    Omar Suliman Zaroog; Aidy Ali; B. B. Sahari; Rizal Zahari

    2011-01-01

    The initial induced compressive residual stresses relax during component operating life and it is important to consider the relaxation phenomenon in the design of the component. In this study, 2024-T 351 aluminium alloy specimens were shot peened under three different shot-peening intensities. Cyclic tests for two load magnitudes were performed for 1, 2, 10, 1000 and 10,000 cycles. The initial

  3. Corrosion Behaviour of Aluminium in the Presence of an Aqueous Extract of Hibiscus Rosa-sinensis

    Microsoft Academic Search

    S. Rajendran; J. Jeyasundari; P. Usha; J. A. Selvi; B. Narayanasamy; A. P. P. Regis; P. Rengan

    2009-01-01

    The inhibition efficiency (IE) of an aqueous extract of Hibiscus rosa-sinensis (white) in controlling corrosion of aluminium at pH 12 has been evaluated by weight loss method in the absence and presence of Zn 2+ . The formulation consisting of 8 mL flower extract (FE) and 50 ppm of Zn 2+ had 98% inhibition efficiency. Polarization study revealed that this

  4. Model of Non-premixed Combustion of Aluminium---Air Mixtures

    Microsoft Academic Search

    Boris Khasainov; Allen Kuhl; Sergey Victorov; Peter Neuwald

    2005-01-01

    For solving the problem of shock-induced dissemination and burning of aluminium particles in air, we have developed a new solver based on equilibrium equation of states (EOS) of 2-phase reactive mixtures. The solver uses two pre-calculated tables; the larger one describes the equilibrium states of reaction products and the smaller one describes states of fresh air. Being linked with gas-dynamics

  5. The use of aluminium lake of nuclear fast red in plant material succesively with alcian blue

    Microsoft Academic Search

    K. Beneš; M. Kamínek

    1973-01-01

    The successive staining alcian blue\\/aluminium lake of nuclear fast red was proved a useful tool for studies on plant root\\u000a tip. A simple and reliable procedure is given resulting in blue cell walls, almost colourless cytoplasm and red nuclei. Attempts\\u000a were made to apply spectrophotometry and paper chromatography to overcome the confusions in manufacturers’ labelling of the\\u000a dye and to

  6. Counteraction of particulate segregation during transient liquid-phase bonding of aluminium-based MMC material

    Microsoft Academic Search

    Z. Li; Y. Zhou; T. H. North

    1995-01-01

    Particle segregation during transient liquid-phase bonding of aluminium-based metal matrix composite material using copper filler metal was investigated. Segregation was promoted by the slow movement of the solid-liquid interface during isothermal solidification and alumina particles with diameters less than 30 ?m were segregated when the copper foil thickness exceeded 5 and 15 ?m for the base metals examined. When bonding

  7. Electrochemical Study of Aluminium Alloy AA 5083 Corrosion Induced by Elemental Mercury in LNG Industries

    Microsoft Academic Search

    D. Zerouali; Z. Derriche; M. Y. Azri

    2006-01-01

    Electrochemical corrosion studies of industrial Aluminium alloy AA 5083 corrosion in natural gas containing mercury metal and water as impurities showed to be a complex process. Single scan voltamograms of amalgamated electrode presents peaks of electrochemical oxidation around E = -1.4 volt\\/SCE and a corrosion potential Ecor = -1.6 volt\\/SCE showing an active amalgamated surface. Oxydation peak, Ip relating rate

  8. Surface nanocrystallization of 7A04 aluminium alloy induced by circulation rolling plastic deformation

    Microsoft Academic Search

    Hui-qiong YE; Xin-min FAN

    2006-01-01

    The surface nanocrystalline microstructures of 7A04 aluminium alloy was obtained by means of circulation rolling plastic deformation(CRPD), the grain refinement behavior and the hardness variation were examined. X-ray diffraction(XRD) and transmission electron microscopy(TEM) were applied to characterize the microstructure of the surface layer. The experimental evidences show that, after the CRPD treatment, the mean grain size in the surface layer

  9. Analysis of natural convective heat transfer of nano coated aluminium fins using Taguchi method

    NASA Astrophysics Data System (ADS)

    Senthilkumar, R.; Nandhakumar, A. J. D.; Prabhu, S.

    2013-01-01

    Rectangular aluminium fins were preferred for analysis and coated by carbon nano tubes using PVD to enhance the heat transfer rate of fins. Convective heat transfer rates for coated and non-coated surfaces were calculated and compared. The temperature and heat transfer characteristics were investigated using Nusselt, Grashof, Prandtl and Rayleigh numbers and also optimized by Taguchi method and ANOVA analysis. The average percentage of increase in fin efficiency is 5 %.

  10. Research on Aluminium Speciation in Poor Forest Soils Using the Sequential Extraction Method

    Microsoft Academic Search

    B. Walna; J. Siepak; S. Drzyma?a; T. Sobczy?ski

    Research on aluminium speciation was performed using a slightly modified version of Tessier's pro- cedure. The soils under study displayed strongly acidic character (pHKCl of 3.3 - 4.4). The content of alu- minium in the exchangeable (11 mg\\/kg), acid extractable (67 mg\\/kg), oxidizable (2650 mg\\/kg), reducible (658 mg\\/kg) and residual fraction (24,680 mg\\/kg) varied widely. The percentage of labile phase

  11. Microstructural evolution and mechanical properties of oil jet peened aluminium alloy, AA6063-T6

    Microsoft Academic Search

    N. Arun Prakash; R. Gnanamoorthy; M. Kamaraj

    2010-01-01

    Grain size refinement by severe surface plastic deformation is one way of improving the surface properties. This paper describes the microstructural evolution due to severe surface plastic deformation by oil jet peening in aluminium alloy, AA6063-T6. Detail characterization of the treated surfaces using X-ray diffraction analysis and transmission electron microscopy revealed the formation of submicron size grains at and near

  12. TEM characterisation of near surface deformation resulting from lubricated sliding wear of aluminium alloy and composites

    Microsoft Academic Search

    J. C. Walker; I. M. Ross; W. M. Rainforth; M. Lieblich

    2007-01-01

    Aluminium alloy composites have been extensively investigated for use in tribo-contact applications, however little detailed literature exists on the sub-surface microstructural evolution as a result of lubricated sliding wear. In this study two un-reinforced alloys (2124 and 5056) and identical alloy composites, reinforced with 15vol.% MoSi2 intermetallic particles were produced by a powder metallurgy route and subject to lubricated sliding

  13. Microstructure mapping in friction stir welds of 7449 aluminium alloy using SAXS

    Microsoft Academic Search

    M. Dumont; A. Steuwer; A. Deschamps; M. Peel; P. J. Withers

    2006-01-01

    This paper describes the microstructural response of an age-hardenable, high-strength 7449 aluminium alloy to friction stir welding. Plates in the naturally aged (T3) and over-aged (T79) conditions were welded using two weld tool translation speeds. Maps of precipitate volume fraction and size were obtained by spatially resolved small-angle X-ray scattering over a cross-section of the welded plate, complemented by direct

  14. Structure and phase transformation behaviour of electroless Ni–W–P on aluminium alloy

    Microsoft Academic Search

    Yong-jun Hu; Tian-xu Wang; Ji-long Meng; Qian-yang Rao

    2006-01-01

    In this paper, the structure and phase transformation behavior of as-deposited and heated Ni–W–P deposits on aluminium alloy were investigated using differential scanning calorimetry (DSC), X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. Deposits were heated at temperatures ranging from 200 to 600 for 1 h. The TEM images of the as-deposited and heated at 200 for 1 h

  15. The effects of pre-ageing on a thermomechanically treated 6201 aluminium alloy

    Microsoft Academic Search

    M. T. Jahn; W. C. Chang

    1988-01-01

    The effects of pre-ageing on the tensile properties of a thermomechanically treated 6201 aluminium alloy were examined. It was found that the pre-ageing effects can be either beneficial or detrimental depending on the amount of cold work applied prior to final ageing. The pre-ageing performed was at 135° C for 30 min. The final ageing was at 140° C for

  16. Deformation structures in 6082 aluminium alloy after severe plastic deformation by equal-channel angular pressing

    Microsoft Academic Search

    Manping Liu; Hans J. Roven; Yingda Yu; Jens C. Werenskiold

    2008-01-01

    Deformation structures of a commercial Al–Mg–Si alloy (6082) processed by equal-channel angular pressing at room temperature were characterized by transmission electron microscopy. Deformation twins, which have never been observed in coarse-grained aluminium, were experimentally confirmed together with numerous other features. The possible roles of twinning and different grain boundary structures on the severe plastic deformation (SPD) mechanisms, including grain refinement,

  17. Characterisation of sealed anodic films on 7050 T74 and 2214 T6 aluminium alloys

    Microsoft Academic Search

    Fanny Snogan; Christine Blanc; Georges Mankowski; Nadine Pébère

    2002-01-01

    Anodic films grown on 7050 T74 and 2214 T6 aluminium alloys by sulfuric acid anodising, and sealed in a Ni and Co acetate solution have been observed by scanning (SEM) and transmission (TEM) electron microscopy, and have been chemically analysed by X-ray photoelectron, secondary ion mass and glow-discharge optical emission spectroscopy. Corrosion behaviour has been investigated in a 0.1 M

  18. Transmission electron microscopy on the microstructure of 7050 aluminium alloy in the T74 condition

    Microsoft Academic Search

    Jin Yan; Li Chunzhi; Yan Minggao

    1992-01-01

    The microstructure of 7050 aluminium alloy in the T74 condition has been investigated by transmission electron microscopy. It was found that the alloy contains the superlattice Al3Zr phase, ?' phase and Al7Cu2Fe constituent phase. The ?' phase is proposed to have an orthorhombic crystal structure witha=0.492 nm,b=0.852 nm andc=0.701 nm. The orientation relationship between the matrix and ?' phase is

  19. Development of porous anodic films on 2014-T4 aluminium alloy in tetraborate electrolyte

    Microsoft Academic Search

    A. Pakes; G. E. Thompson; P. Skeldon; P. C. Morgan

    2003-01-01

    Anodic film growth on 2014-T4 aluminium alloy at 60 V in 50 gl?1 di-sodium tetraborate at 60 °C has been examined by transmission electron microscopy and Rutherford backscattering spectroscopy. Initial film growth proceeds at relatively high efficiency on the initially etched and desmutted alloy. During the subsequent period of current decline, the reactive electrolyte species penetrate the outer film at

  20. Characterisation of early precipitation stages in 6xxx series aluminium alloys

    Microsoft Academic Search

    Håkon S. Hasting; John Walmsley; Calin D. Marioara; ATJ van Helvoort; Randi Holmestad; Frederic Danoix; Williams Lefebvre

    2006-01-01

    Advanced microscopy techniques such as high angular annular dark field scanning transmission electron microscopy and energy filtered transmission electron microscopy are being explored to study early precipitation stages of 6XXX-series aluminium alloys. Observations are combined with those from 3 dimensional atom probe studies of the same materials. GP-zones are imaged by annular dark field scanning transmission electron microscopy and plasmon

  1. Transmission electron microscopy on the microstructure of 7050 aluminium alloy in the T74 condition

    Microsoft Academic Search

    Jin Yan; Li Chunzhi; Yan Minggao

    1992-01-01

    The microstructure of 7050 aluminium alloy in the T74 condition has been investigated by transmission electron microscopy.\\u000a It was found that the alloy contains the superlattice Al3Zr phase, ?? phase and Al7Cu2Fe constituent phase. The ?? phase is proposed to have an orthorhombic crystal structure witha=0.492 nm,b=0.852 nm andc=0.701 nm. The orientation relationship between the matrix and ?? phase is

  2. Characterization of the after thixoforming microstructure of a 7075 aluminium alloy gear

    Microsoft Academic Search

    ?. Rogal; J. Dutkiewicz; A. Góral; B. Olszowska-Sobieraj; J. Da?ko

    2010-01-01

    Among various methods of material preparation before thixoforming, applied to obtain globular microstructure, like cold or\\u000a hot deformation, Equal Channel Angular Pressing ECAP allows to obtain the correct microstructure after heating to the semi-solid\\u000a range. In the present study 7075 aluminium alloy was cold pressed using ECAP method in order to obtain the appropriate semi-solid\\u000a range microstructure. The bar of

  3. Microstructure, local and global mechanical properties of friction stir welds in aluminium alloy 6005AT6

    Microsoft Academic Search

    A. Simar; Y. Bréchet; B. de Meester; A. Denquin; T. Pardoen

    2008-01-01

    The effect of the welding speed on the microstructure, local and overall mechanical properties of friction stir welded joints has been investigated in the aluminium alloy 6005A-T6. The fine hardening precipitation within the heat-affected zone has been characterized by differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). Post-welding heat treatments have been applied to obtain indications on the level

  4. Growth mode and electronic structure of copper films on aluminium substrates

    Microsoft Academic Search

    C. J. Barnes; H. Asonen; A. Salokatve; M. Pessa

    1987-01-01

    The growth mode, geometric and electronic structure of thin copper films deposited onto aluminium single crystal substrates have been studied by LEED, AES, angle-resolved UPS and work function changes. Growth occurs in a quasi-layer-by-layer fashion on Al(111). Temperature dependent interdiffusion leads to formation of a mixed Cu\\/Al interface upon which ordered epitaxial films eventually grow. The ordered structure is rotationally

  5. Secondary aluminium-iron (III) chloride batteries with a low temperature molten salt electrolyte

    Microsoft Academic Search

    F. M. Donahue; S. E. Mancini; L. Simonsen

    1992-01-01

    Secondary aluminium-iron (III) chloride batteries using a low temperature molten salt electrolyte were constructed and tested. Discharge current densities were in the range 5 to 100 mA (~ 1 to 20 mA cm-2; ~C\\/4 to 5C); charging currents were 5mA (C\\/4 toC\\/2). Utilization of the positive electrode reactant was low due to the discharge rates and loading procedure. The mode

  6. Characterization of some aluminium alloys for application as anodes in alkaline batteries

    Microsoft Academic Search

    S. Zein El Abedin; A. O. Saleh

    2004-01-01

    This work deals with the evaluation and characterization of aluminium (99.61%) and some of its alloys namely, Al—Ga—In, Al—Zn, Al—In, Al—Mn and Al—Mg, as anodes in alkaline battery electrolyte. The self-corrosion rate, hydrogen evolution rate and electrochemical properties, such as open circuit potentials, polarization characteristics and anode efficiencies were examined in 4 M KOH solutions. Among the tested alloys, Al—Ga—In

  7. Comparative efficacy and toxicity of desferrioxamine, deferiprone and other iron and aluminium chelating drugs

    Microsoft Academic Search

    George J. Kontoghiorghes

    1995-01-01

    The efficacy and toxicity aspects of the iron and aluminium chelating drugs desferrioxamine and deferiprone (L1, 1,2-dimethyl-3-hydroxypyrid-4-one), have been compared. Major emphasis was given in the use of these two and also of other chelators in conditions of iron overload, imbalance and toxicity, as well as the incidence and possible causes of toxic side effects in both animals and humans.

  8. Thermolysis of 2,4,6-trichlorophenol chemisorbed on aluminium oxides as example of fly ash mediated surface catalysis reaction in PCDD\\/PCDF formation

    Microsoft Academic Search

    Ernest Von?ina; Tomaž Šolmajer

    2002-01-01

    The influence of aluminium cation as a strong electrophilic centre on the thermolysis of chlorophenols chemisorbed on Al(OH)3 surface was investigated. If thermolysis is carried out at 300 °C the spontaneous rupture of the bond between aluminium and oxygen of phenol takes place in the temperature range of 260–280 °C. The thermolysis of chlorophenoxy aluminium compounds occurs through homolytic and

  9. Can hazardous waste become a raw material? The case study of an aluminium residue: a review.

    PubMed

    López-Delgado, Aurora; Tayibi, Hanan

    2012-05-01

    The huge number of research studies carried out during recent decades focused on finding an effective solution for the waste treatment, have allowed some of these residues to become new raw materials for many industries. Achieving this ensures a reduction in energy and natural resources consumption, diminishing of the negative environmental impacts and creating secondary and tertiary industries. A good example is provided by the metallurgical industry, in general, and the aluminium industry in this particular case. The aluminium recycling industry is a beneficial activity for the environment, since it recovers resources from primary industry, manufacturing and post-consumer waste. Slag and scrap which were previously considered as waste, are nowadays the raw material for some highly profitable secondary and tertiary industries. The most recent European Directive on waste establishes that if waste is used as a common product and fulfils the existing legislation for this product, then this waste can be defined as 'end-of-waste'. The review presented here, attempts to show several proposals for making added-value materials using an aluminium residue which is still considered as a hazardous waste, and accordingly, disposed of in secure storage. The present proposal includes the use of this waste to manufacture glass, glass-ceramic, boehmite and calcium aluminate. Thus the waste might effectively be recovered as a secondary source material for various industries. PMID:22071175

  10. Shear Strength Response of the Aluminium Alloy 6082-T6 During One-Dimensional Shock Loading

    NASA Astrophysics Data System (ADS)

    Harrigan, John; Millett, Jeremy; Bourne, Neil

    2007-06-01

    The measurement of shear strength via the use of lateral stress gauges has been shown to be a viable technique in a number of materials. An experimental investigation on the intermediate-rate behaviour and shock response of the aluminium alloy, 6082-T6, is reported here. Results obtained using the lateral stress gauge technique show that the shear strength increases with impact stress. The lateral stress behind the shock front is seen to be relatively flat, unlike many other face-centred cubic metals and alloys, where a decrease in lateral stress indicates an increase in shear strength. This unusual response may be a reflection of the high stacking fault energy of aluminium and its alloys resulting in a reduction of the work hardening (i.e. increases in dislocation and/or twin density). Further plate impact results show that the Hugoniot of 6082-T6 is in effect identical to that of the more widely known 6061-T6. Split Hopkinson pressure bar results are used to provide a fuller picture of the rate-dependant behaviour of 6082-T6 over a range loading rates and conditions. Key words: shear strength, aluminium alloy, one-dimensional shock

  11. Speciation study of aluminium in beverages by Competitive Ligand Exchange-Adsorptive Stripping Voltammetry.

    PubMed

    Magnier, A; Fekete, V; Van Loco, J; Bolle, F; Elskens, M

    2014-05-01

    Competitive Ligand Exchange-Adsorptive Stripping Voltammetry (CLE-AdSV) was used for determining the speciation of aluminium in commonly consumed beverages (water, tea, infusion, coffee, orange juice, tomato juice, beer and red wine). Aluminium determination involves the adsorption of Al-complexes with the ligand cupferron onto a hanging mercury drop electrode. All samples were studied at pH 6.5 with an accumulation step at -0.60 V (all potential values in the paper are given versus the Ag/AgCl, [KCl]=3 M reference electrode) during 60 s, and a final cupferron concentration of 4 × 10(-4)M. These conditions were used to establish (i) the concentration of electro-labile aluminium, (ii) the range of ligand concentrations and (iii) the conditional stability constants of beverage samples using titration procedures. The results based on Ruzic plots were compared to computer simulation with Visual MINTEQ. This comparison suggests that labile monomeric Al-forms and soluble organic complexes of low molecular weight can be quantified by the CLE-AdSV procedure. Overall the relative uncertainties on the determination of the electro-active Al fraction and the complexing parameters, i.e., concentration and conditional stability constant of natural ligands in the samples, are less than 15%. Thanks to these results, information on Al bioavailability in beverages was collected and discussed. This study also illustrates the value of computer simulations when complex, time-consuming voltammetric techniques are applied. PMID:24720958

  12. Aluminium ultrahigh vacuum system for the 3 GeV TPS synchrotron light source

    NASA Astrophysics Data System (ADS)

    Hsiung, G. Y.; Chang, C. C.; Chen, C. L.; Wu, L. H.; Cheng, C. M.; Chan, C. K.; Yang, Y. C.; Hsueh, H. P.; Hsu, S. N.; Chen, J. R.

    2013-06-01

    The 3-GeV Taiwan Photon Source (TPS) is a large accelerator and synchrotron light source of circumference 518.4 m. The electron storage ring of TPS requires an ultrahigh-vacuum pressure per beam current less than 2×10-10 Pa/mA in the beam duct to maintain a long life of the circulating beam without scattering of ions by residual gases. Aluminium alloys used for the beam ducts have a benefit of greater thermal conductivity that simplifies the structure of vacuum vessels built with the cooling components. Machining completely free of oil applied to the aluminium chambers followed by cleaning with ozonized water and welding in house provide a precise dimensional control within 0.3 mm and a clean surface with a small rate ~ 6.4×10-12 Pa m/s of thermal outgassing after baking at 150 °C for 24 h. The assembled ion pump with non-evaporable getter pump is capable of evacuating the chamber to a pressure < 1×10-9 Pa. The average pressure inside the duct is expected to be sufficiently small. The clean process to manufacture the aluminium ultrahigh vacuum system is described.

  13. Iron and aluminium oxides containing industrial wastes as adsorbents of heavy metals: Application possibilities and limitations.

    PubMed

    Jacukowicz-Sobala, Irena; Oci?ski, Daniel; Kocio?ek-Balawejder, El?bieta

    2015-07-01

    Industrial wastes with a high iron or aluminium oxide content are produced in huge quantities as by-products of water treatment (water treatment residuals), bauxite processing (red mud) and hard and brown coal burning in power plants (fly ash). Although they vary in their composition, the wastes have one thing in common - a high content of amorphous iron and/or aluminium oxides with a large specific surface area, whereby this group of wastes shows very good adsorbability towards heavy metals, arsenates, selenates, etc. But their physical form makes their utilisation quite difficult, since it is not easy to separate the spent sorbent from the solution and high bed hydraulic resistances occur in dynamic regime processes. Nevertheless, because of the potential benefits of utilising the wastes in industrial effluent treatment, this issue attracts much attention today. This study describes in detail the waste generation processes, the chemical structure of the wastes, their physicochemical properties, and the mechanisms of fixing heavy metals and semimetals on the surface of iron and aluminium oxides. Typical compositions of wastes generated in selected industrial plants are given. A detailed survey of the literature on the adsorption applications of the wastes, including methods of their thermal and chemical activation, as well as regeneration of the spent sorbents, is presented. The existing and potential ways of modifying the physical form of the discussed group of wastes, making it possible to overcome the basic limitation on their practical use, are discussed. PMID:26060197

  14. Modelling of stress fields during LFEM DC casting of aluminium billets by a meshless method

    NASA Astrophysics Data System (ADS)

    Mavri?, B.; Šarler, B.

    2015-06-01

    Direct Chill (DC) casting of aluminium alloys is a widely established technology for efficient production of aluminium billets and slabs. The procedure is being further improved by the application of Low Frequency Electromagnetic Field (LFEM) in the area of the mold. Novel LFEM DC processing technique affects many different phenomena which occur during solidification, one of them being the stresses and deformations present in the billet. These quantities can have a significant effect on the quality of the cast piece, since they impact porosity, hot-tearing and cold cracking. In this contribution a novel local radial basis function collocation method (LRBFCM) is successfully applied to the problem of stress field calculation during the stationary state of DC casting of aluminium alloys. The formulation of the method is presented in detail, followed by the presentation of the tackled physical problem. The model describes the deformations of linearly elastic, inhomogeneous isotropic solid with a given temperature field. The temperature profile is calculated using the in-house developed heat and mass transfer model. The effects of low frequency EM casting process parameters on the vertical, circumferential and radial stress and on the deformation of billet surface are presented. The application of the LFEM appears to decrease the amplitudes of the tensile stress occurring in the billet.

  15. Energy absorption behavior of closed-cell aluminium foam under drop mass impact tests

    NASA Astrophysics Data System (ADS)

    Yang, Fujun; Ni, Siyuan; He, Xiaoyuan; He, Deping

    2008-11-01

    Quasi-static axial compression and drop mass impact tests were performed to study the energy absorption behaviour of the closed-cell aluminium foam. Digital image analysis was firstly used to characterize the surface's structure of individual cells and aggregates of cells. The cell structure characterizations performed using the best-fit ellipse equivalent diameter for the individual cells, which included measurement of the size distribution of cells, cell's aspect ratio and orientation. It shows that the statistical distribution of cells' size and cell's aspect ratio well follow Gauss distributions. The energy absorption behavior of the high porosities aluminium foam under static and drop weight impact compression were then conducted. High-speed imaging technique and temporal digital image correlation method were employed to evaluate the deformation and acceleration in the compression experiments. Using these approaches, the deformation and energy absorption mechanism of Al foam due to drop impact can be observed and better understood. The experimental results show that aluminium foams are quite close to a kind of isotropic structure and have high energy absorption capabilities.

  16. Crashworthiness of Aluminium Tubes; Part 2: Improvement of Hydroforming Operation to Increase Absorption Energy

    NASA Astrophysics Data System (ADS)

    D'Amours, Guillaume; Rahem, Ahmed; Mayer, Robert; Williams, Bruce; Worswick, Michael

    2007-05-01

    The motivation to reduce overall vehicle weight within the automotive sector drives the substitution of lightweight materials such as aluminium alloys for structural components. Such a substitution requires a significant amount of development to manufacture structurally parts such that the energy absorption characteristics are not sacrificed in the event of crash. The effects of the manufacturing processes on the crash performance of automotive structural components must be better understood to ensure improved crashworthiness. This paper presents results of an experimental and numerical investigation of the crash response and energy absorption properties of impacted hydroformed aluminium alloy tubes. Crash experiments on hydroformed tubes were performed using a deceleration sled test at the General Motors Technical Center. Results from axial crush testing showed that an important parameter that influences the energy absorption characteristics during crash was the thickness reduction caused by circumferential expansion of the tube during hydroforming. It was found that that the energy absorption decreased as the corner radius decreased, which results because of increased thinning. Sensitivity studies of end feeding parameters, such as end feed level and profile, were carried out to evaluate their impact on the energy absorption of the aluminium tubes.

  17. NLTE determination of the aluminium abundance in a homogeneous sample of extremely metal-poor stars

    E-print Network

    S. M. Andrievsky; M. Spite; S. A. Korotin; F. Spite; P. Bonifacio; R. Cayrel; V. Hill; P. François

    2008-02-11

    Aims: Aluminium is a key element to constrain the models of the chemical enrichment and the yields of the first supernovae. But obtaining precise Al abundances in extremely metal-poor (EMP) stars requires that the non-LTE effects be carefully taken into account. Methods: The NLTE profiles of the blue resonance aluminium lines have been computed in a sample of 53 extremely metal-poor stars with a modified version of the program MULTI applied to an atomic model of the Al atom with 78 levels of Al I and 13 levels of Al II, and compared to the observations. Results: With these new determinations, all the stars of the sample show a ratio Al/Fe close to the solar value: [Al/Fe] =-0.06 +- 0.10 with a very small scatter. These results are compared to the models of the chemical evolution of the halo using different models of SN II and are compatible with recent computations. The sodium-rich giants are not found to be also aluminium-rich and thus, as expected, the convection in these giants only brings to the surface the products of the Ne-Na cycle.

  18. Molybdenum, Tungsten, and Aluminium Substitution for Enhancement of the Thermoelectric Performance of Higher Manganese Silicides

    NASA Astrophysics Data System (ADS)

    Nhi Truong, D. Y.; Berthebaud, David; Gascoin, Franck; Kleinke, Holger

    2015-06-01

    An easy and efficient process involving ball milling under soft conditions and spark plasma sintering was used to synthesize higher manganese silicide (HMS)-based compounds, for example MnSi1.75Ge0.02, with different molybdenum, tungsten, and aluminium substitution. The x-ray diffraction patterns of the samples after sintering showed the main phase to be HMS with the presence of some side products. Molybdenum substitution enlarges the unit cells more than tungsten substitution, owing to its greater solubility in the HMS structure, whereas substitution with aluminium did not substantially alter the cell parameters. The electrical resistivity of HMS-based compounds was reduced by <10% by this substitution, because of increased carrier concentrations. Changes of the Seebeck coefficient were insignificant after molybdenum and aluminium substitution whereas tungsten substitution slightly reduced the thermopower of the base material by approximately 8% over the whole temperature range; this was ascribed to reduced carrier mobility as a result of enhanced scattering. Substitution with any combination of two of these elements resulted in no crucial modification of the electrical properties of the base material. Large decreases of lattice thermal conductivity were observed, because of enhanced phonon scattering, with the highest reduction up to 25% for molybdenum substitution; this resulted in a 20% decrease of total thermal conductivity, which contributed to improvement of the figure of merit ZT of the HMS-based materials. The maximum ZT value was approximately 0.40 for the material with 2 at.% molybdenum substitution at the Mn sites.

  19. Crashworthiness of Aluminium Tubes; Part 2: Improvement of Hydroforming Operation to Increase Absorption Energy

    SciTech Connect

    D'Amours, Guillaume; Rahem, Ahmed [National Research Council Canada, Aluminium Technology Centre, 501 University Blvd. East, Chicoutimi, Quebec, G7H 8C3 (Canada); Mayer, Robert [General Motors Technical Centre, 6250 Chicago Road, Warren, MI (United States); Williams, Bruce; Worswick, Michael [University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1 (Canada)

    2007-05-17

    The motivation to reduce overall vehicle weight within the automotive sector drives the substitution of lightweight materials such as aluminium alloys for structural components. Such a substitution requires a significant amount of development to manufacture structurally parts such that the energy absorption characteristics are not sacrificed in the event of crash. The effects of the manufacturing processes on the crash performance of automotive structural components must be better understood to ensure improved crashworthiness. This paper presents results of an experimental and numerical investigation of the crash response and energy absorption properties of impacted hydroformed aluminium alloy tubes. Crash experiments on hydroformed tubes were performed using a deceleration sled test at the General Motors Technical Center. Results from axial crush testing showed that an important parameter that influences the energy absorption characteristics during crash was the thickness reduction caused by circumferential expansion of the tube during hydroforming. It was found that that the energy absorption decreased as the corner radius decreased, which results because of increased thinning. Sensitivity studies of end feeding parameters, such as end feed level and profile, were carried out to evaluate their impact on the energy absorption of the aluminium tubes.

  20. Recovery of aluminium, nickel-copper alloys and salts from spent fluorescent lamps

    SciTech Connect

    Rabah, Mahmoud A

    2004-07-01

    This study explores a combined pyro-hydrometallurgical method to recover pure aluminium, nickel-copper alloy(s), and some valuable salts from spent fluorescent lamps (SFLs). It also examines the safe recycling of clean glass tubes for the fluorescent lamp industry. Spent lamps were decapped under water containing 35% acetone to achieve safe capture of mercury vapour. Cleaned glass tubes, if broken, were cut using a rotating diamond disc to a standard shorter length. Aluminium and copper-nickel alloys in the separated metallic parts were recovered using suitable flux to decrease metal losses going to slag. Operation variables affecting the quality of the products and the extent of recovery with the suggested method were investigated. Results revealed that total loss in the glass tube recycling operation was 2% of the SFLs. Pure aluminium meeting standard specification DIN 1712 was recovered by melting at 800 deg. C under sodium chloride/carbon flux for 20 min. Standard nickel-copper alloys with less than 0.1% tin were prepared by melting at 1250 deg. C using a sodium borate/carbon flux. De-tinning of the molten nickel-copper alloy was carried out using oxygen gas. Tin in the slag as oxide was recovered by reduction using carbon or hydrogen gas at 650-700 deg. C. Different valuable chloride salts were also obtained in good quality. Further research is recommended on the thermodynamics of nickel-copper recovery, yttrium and europium recovery, and process economics.