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1

[Aluminium content in foods with aluminium-containing food additives].  

PubMed

The aluminium (Al) content of 105 samples, including bakery products made with baking powder, agricultural products and seafoods treated with alum, was investigated. The amounts of Al detected were as follows (limit of quantification: 0.01 mg/g): 0.01-0.37 mg/g in 26 of 57 bakery products, 0.22-0.57 mg/g in 3 of 6 powder mixes, 0.01-0.05 mg/g in all three agricultural products examined, 0.03-0.90 mg/g in 4 of 6 seafood samples, 0.01-0.03 mg/g in 3 of 11 samples of instant noodles, 0.04-0.14 mg/g in 3 of 4 samples of vermicelli, 0.01 mg/g in 1 of 16 soybean products, but none in soybeans. Amounts equivalent to the PTWI of a 16 kg infant were detected in two samples of bakery products, two samples of powder mixes and one sample of salted jellyfish, if each sample was taken once a week. These results suggest that certain foods, depending on the product and the intake, might exceed the PTWI of children, especially infants. PMID:22450671

Ogimoto, Mami; Suzuki, Kumi; Kabashima, Junichiro; Nakazato, Mitsuo; Uematsu, Yoko

2012-01-01

2

Aluminium content of some foods and food products in the USA, with aluminium food additives.  

PubMed

The primary objective was to determine the aluminium (Al) content of selected foods and food products in the USA which contain Al as an approved food additive. Intake of Al from the labeled serving size of each food product was calculated. The samples were acid or base digested and analysed for Al using electrothermal atomic absorption spectrometry. Quality control (QC) samples, with matrices matching the samples, were generated and used to verify the Al determinations. Food product Al content ranged from <1-27,000 mg kg(-1). Cheese in a serving of frozen pizzas had up to 14 mg of Al, from basic sodium aluminium phosphate; whereas the same amount of cheese in a ready-to-eat restaurant pizza provided 0.03-0.09 mg. Many single serving packets of non-dairy creamer had approximately 50-600 mg Al kg(-1) as sodium aluminosilicate, providing up to 1.5 mg Al per serving. Many single serving packets of salt also had sodium aluminosilicate as an additive, but the Al content was less than in single-serving non-dairy creamer packets. Acidic sodium aluminium phosphate was present in many food products, pancakes and waffles. Baking powder, some pancake/waffle mixes and frozen products, and ready-to-eat pancakes provided the most Al of the foods tested; up to 180 mg/serving. Many products provide a significant amount of Al compared to the typical intake of 3-12 mg/day reported from dietary Al studies conducted in many countries. PMID:16019791

Saiyed, Salim M; Yokel, Robert A

2005-03-01

3

New Developments of Laser Processing Aluminium Alloys via Additive Manufacturing Technique  

Microsoft Academic Search

The significance of this research lies in its potential to create an Additive Manufacturing technology of novel lightweight materials for industrial applications. The work reported here focuses on studies performed with low power fiber laser and investigates the feasibility of introducing high strength aluminium alloys and custom developed Al powder systems to the Selective Laser Melting (SLM) process. Al-Si powder

Konrad Bartkowiak; Sven Ullrich; Thomas Frick; Michael Schmidt

2011-01-01

4

Effect of element additions on wear property of eutectic aluminium-silicon alloys  

Microsoft Academic Search

The effects of cerium, zinc and zirconium additions and subsequent heat treatment on wear of the eutectic aluminium-silicon alloys have been investigated in dry sliding against a steel counterface by using a pin-on-disc machine. Wear surfaces and debris were examined by scanning electron microscopy. Wear characteristics of both binary Al-Si alloys and a commercial LM 13 alloy, were also studied

Mohd Harun; I. A. Talib; A. R. Daud

1996-01-01

5

Hot-pressing behaviour of silicon carbide powders with additions of aluminium oxide  

Microsoft Academic Search

The hot-pressing behaviour of different silicon carbide powders (average particle sizes ranging from ~ 0.5 to 9 µm) with aluminium oxide additions ranging from 0.01 to 0.15 volume fractions was investigated. Using powders with an average particle size -2 for volume fractions of AI2O3\\u000a$$\\\\bar > $$\\u000a 0.02. A liquid phase forms at high temperatures which dissolves the silicon carbide

F. F. Lange

1975-01-01

6

The Effect of the Order of Reagent Addition on the Settling Rate of Aluminium Hydroxide in the Al(III)Na2CO3 System  

Microsoft Academic Search

The effects of several factors on the settling rate of aluminiumhydroxide were investigated during chemical coagulation using aluminium salts. Experimental variables were pH, aluminium (III) concentration and the order of addition of reagents. Experiments were carried out at pH 5–8 and rapid settling was achieved when aluminium (III) solutions were added to Na2CO3 solutions near neutral pH, close to the

Birsen Demirata; Re?at Apak; Gülcin Gümüs; Hüseyin Afsar

2002-01-01

7

Microstructure and impression creep of age hardenable AA2219 aluminium alloy modified by Sc, Mg and Zr additions  

Microsoft Academic Search

The present work pertains to impression creep of age hardenable AA2219 Aluminium-copper (6.3%) alloy correlated with microstructure\\u000a with the addition of scandium, magnesium and zirconium. These additions were systematically varied by preparing alloys of\\u000a different composition using gas tungsten arc melting. Impression creep technique was used to study the high temperature stability\\u000a of the alloys. Modified compositions of the alloy

K. Srinivasa Rao; P. Naga Raju; G. M. Reddy; K. Prasad Rao

2010-01-01

8

Stabilization of FGD gypsum for its disposal in landfills using amorphous aluminium oxide as a fluoride retention additive.  

PubMed

The applicability of amorphous aluminium oxide as a fluoride retention additive to flue gas desulphurisation (FGD) gypsum was studied as a way of stabilizing this by-product for its disposal in landfills. Using a batch method the sorption behaviour of amorphous aluminium oxide was evaluated at the pH (about 6.5) and background electrolyte conditions (high chloride and sulphate concentrations) found in FGD gypsum leachates. It was found that fluoride sorption on amorphous aluminium oxide was a very fast process with equilibrium attained within the first half an hour of interaction. The sorption process was well described by the Langmuir model, offering a maximum fluoride sorption capacity of 61.7 mg g(-1). Fluoride sorption was unaffected by chloride co-existing ions, while slightly decreased (about 20%) by competing sulphate ions. The use of amorphous aluminium oxide in the stabilization of FGD gypsum proved to greatly decreased its fluoride leachable content (in the range 5-75% for amorphous aluminium oxide doses of 0.1-2%, as determined by the European standard EN 12457-4 [EN-12457-4 Characterization of waste-leaching-compliance test for leaching of granular waste materials and sludges-Part 4: one stage batch test at a liquid to solid ratio of 10 l/kg for materials with particle size below 10mm (without or with size reduction)]), assuring the characterization of this by-product as a waste acceptable at landfills of non-hazardous wastes according to the Council Decision 2003/33/EC [Council Decision 2003/33/EC of 19 December 2002. Establishing criteria and procedures for the acceptance of waste at landfills pursuant to Article 16 of and Annex II to Directive 1999/31/EC] on landfill of wastes. Furthermore, as derived from column leaching studies, the proposed stabilization system proved to be highly effective in simulated conditions of disposal, displaying a fluoride leaching reduction value about 81% for an amorphous aluminium oxide added amount of 2%. PMID:17509651

Alvarez-Ayuso, E; Querol, X

2007-09-01

9

Effect on fresh CSH gels of the simultaneous addition of alkali and aluminium  

Microsoft Academic Search

Reducing Portland cement content in cementitious binders offers a means to address the adverse environmental impacts of Portland cement manufacture. This paper investigates the impacts on hydration product chemistry of partially replacing Portland cement with alkali-activated aluminosilicates. Here, short-term effects of soluble alkali and aluminium, likely to be available in an alkali-activated system, on the structure of synthetic C-S-H gels

I. García Lodeiro; A. Fernández-Jimenez; A. Palomo; D. E Macphee

2010-01-01

10

Gypsum addition to soils contaminated by red mud: implications for aluminium, arsenic, molybdenum and vanadium solubility.  

PubMed

Red mud is highly alkaline (pH 13), saline and can contain elevated concentrations of several potentially toxic elements (e.g. Al, As, Mo and V). Release of up to 1 million m(3) of bauxite residue (red mud) suspension from the Ajka repository, western Hungary, caused large-scale contamination of downstream rivers and floodplains. There is now concern about the potential leaching of toxic metal(loid)s from the red mud as some have enhanced solubility at high pH. This study investigated the impact of red mud addition to three different Hungarian soils with respect to trace element solubility and soil geochemistry. The effectiveness of gypsum amendment for the rehabilitation of red mud-contaminated soils was also examined. Red mud addition to soils caused a pH increase, proportional to red mud addition, of up to 4 pH units (e.g. pH 7 ? 11). Increasing red mud addition also led to significant increases in salinity, dissolved organic carbon and aqueous trace element concentrations. However, the response was highly soil specific and one of the soils tested buffered pH to around pH 8.5 even with the highest red mud loading tested (33 % w/w); experiments using this soil also had much lower aqueous Al, As and V concentrations. Gypsum addition to soil/red mud mixtures, even at relatively low concentrations (1 % w/w), was sufficient to buffer experimental pH to 7.5-8.5. This effect was attributed to the reaction of Ca(2+) supplied by the gypsum with OH(-) and carbonate from the red mud to precipitate calcite. The lowered pH enhanced trace element sorption and largely inhibited the release of Al, As and V. Mo concentrations, however, were largely unaffected by gypsum induced pH buffering due to the greater solubility of Mo (as molybdate) at circumneutral pH. Gypsum addition also leads to significantly higher porewater salinities, and column experiments demonstrated that this increase in total dissolved solids persisted even after 25 pore volume replacements. Gypsum addition could therefore provide a cheaper alternative to recovery (dig and dump) for the treatment of red mud-affected soils. The observed inhibition of trace metal release within red mud-affected soils was relatively insensitive to either the percentage of red mud or gypsum present, making the treatment easy to apply. However, there is risk that over-application of gypsum could lead to detrimental long-term increases in soil salinity. PMID:23793510

Lehoux, Alizée P; Lockwood, Cindy L; Mayes, William M; Stewart, Douglas I; Mortimer, Robert J G; Gruiz, Katalin; Burke, Ian T

2013-10-01

11

Evaluation of flow injection sample to standard addition method for the inductively coupled plasma mass spectrometric determination of aluminium in biological tissues.  

PubMed

An on-line flow injection sample to standard addition method was developed for the determination of aluminium in biological tissues by inductively coupled plasma mass spectrometry. The sample concentration is calculated from two transient signals obtained from the injection of the blank and the sample, using a standard solution as carrier. A flow injection manifold for the on-line injection of both solutions was used and a three-step flow injection programme allowing the two transient signals to be obtained in the same measurement process was applied. A microwave nitric acid digestion procedure in closed vessels was used for sample dissolution, and scandium was added as an internal standard to control plasma fluctuations and to correct for ion signal instability. Tissue samples from healthy rat brain, kidney, liver, lung and spleen were analysed to find their aluminium concentrations. Complete recoveries from rat liver tissue spiked with aluminium concentrations in the 0.5-10.0 micrograms g-1 level were achieved. The detection limit (3 sigma) referred to the solid sample was of 10 ng g-1 and the precision (RSD) was better than 1%. The accuracy of the proposed method was tested by determining the aluminium contents in two NIST Standard Reference Materials: SRM 1577b Bovine Liver and SRM 8414 Bovine Muscle Powder). PMID:8799287

Coedo, A G; Dorado, M T; Ruiz, J; Escudero, M; Rubio, J C

1996-04-01

12

The effect of magnesium additions on the microstructure and cut edge corrosion resistance of zinc aluminium alloy galvanised steel  

Microsoft Academic Search

The magnesium levels in 20?m thick 4.5% Al\\/Zn galvanising coatings applied to 0.7mm gauge steel under continuous galvanising conditions were altered from 0.0% to 0.05%. The additions result in an increase in the zinc dendrites (volume fraction from 6% to 22% and number from 150 to 325mm?2) since magnesium depresses the eutectic temperature increasing the freezing range. The microstructural modification

Jonathan Elvins; John A. Spittle; James H. Sullivan; David A. Worsley

2008-01-01

13

The prophylactic reduction of aluminium intake.  

PubMed

The use of modern analytical methods has demonstrated that aluminium salts can be absorbed from the gut and concentrated in various human tissues, including bone, the parathyroids and brain. The neurotoxicity of aluminium has been extensively characterized in rabbits and cats, and high concentrations of aluminium have been detected in the brain tissue of patients with Alzheimer's disease. Various reports have suggested that high aluminium intakes may be harmful to some patients with bone disease or renal impairment. Fatal aluminium-induced neuropathies have been reported in patients on renal dialysis. Since there are no demonstrable consequences of aluminium deprivation, the prophylactic reduction of aluminium intake by many patients would appear prudent. In this report, the major sources of aluminium in foods and non-prescription drugs are summarized and alternative products are described. The most common foods that contain substantial amounts of aluminium-containing additives include some processed cheeses, baking powders, cake mixes, frozen doughs, pancake mixes, self-raising flours and pickled vegetables. The aluminium-containing non-prescription drugs include some antacids, buffered aspirins, antidiarrhoeal products, douches and haemorrhoidal medications. The advisability of recommending a low aluminium diet for geriatric patients is discussed in detail. PMID:6337934

Lione, A

1983-02-01

14

ADDITION  

NSDL National Science Digital Library

Addition can be so much fun, especially with these games. Tweet, Tweet, Addition is not a game for the birds. Keep the game Math Popper away from all sharp pins! Watch out! Addition facts are attacking the spaceships in Addition Attack In Cannon Math you can shoot people out of a cannon! It is great fun!! Dr. Brain s Robot needs help with his math facts. Can you help ...

Games, Aidan'S M.

2010-12-20

15

Additives  

NASA Technical Reports Server (NTRS)

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.

Smalheer, C. V.

1973-01-01

16

Addition  

NSDL National Science Digital Library

We will practice adding! Practice with Fribbit! Fribbit Addition Help the pirate add his marbles. Pirate Marble Addition Help the whale get to freedom! Save the Whale Catch the correct sum! Fish Addish Balance the sides of the equal sign. Balance Equations ...

Hoffmann, Mrs.

2011-08-09

17

Aluminium in human sweat.  

PubMed

It is of burgeoning importance that the human body burden of aluminium is understood and is measured. There are surprisingly few data to describe human excretion of systemic aluminium and almost no reliable data which relate to aluminium in sweat. We have measured the aluminium content of sweat in 20 healthy volunteers following mild exercise. The concentration of aluminium ranged from 329 to 5329?g/L. These data equate to a daily excretion of between 234 and 7192?g aluminium and they strongly suggest that perspiration is the major route of excretion of systemic aluminium in humans. PMID:24239230

Minshall, Clare; Nadal, Jodie; Exley, Christopher

2014-01-01

18

Evidence of aluminium accumulation in aluminium welders.  

PubMed Central

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.

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

1991-01-01

19

ALUMINIUM: ITS TOXICITY, BIOAVAILABILITY AND RETENTION IN THE HUMAN BODY  

Microsoft Academic Search

Aluminium is commonest metal within the earth's crust. Nevertheless, most natural waters, biota and the air contain very low concentrations. It follows that, except in the case of exposure to pharmaceutical preparations, mans exposure to aluminium - mostly in the diet - is very low. In addition, only a very small fraction of ingested aluminium is bioavailable (0.0001 - 0.01)

N. D. PRIEST

20

Comparative study on the effect of iron and silicon addition on the microstructure and mechanical properties of aluminium-lithium powder atomized alloys  

Microsoft Academic Search

The present work was conducted on a wide series of Al-Si, Al-Li, Al-Li-Si and Al-Li-Fe alloys produced by centrifugal atomization. Solidification in Al-Si powders occurs by heterogeneous nucleation at the interface with the atmosphere, followed by propagation of the solidification front towards the particle centre. Addition of 3% Li to the Al-Si alloys shifts the ternary eutectic point to less

F. H. Samuel; G. Champier; P. Todeschini; J. H. Torres

1992-01-01

21

Aluminium–aluminium compound fabrication by high pressure die casting  

Microsoft Academic Search

This study examines the development of aluminium–aluminium compounds during high pressure die casting. An aluminium insert was mounted into a die casting mould and embedded into an aluminium casting alloy. Prior to that, the natural oxide layer of the insert was removed and replaced by zinc coatings with different thicknesses. During the casting process the zinc layer dissolves and a

M. Rübner; M. Günzl; C. Körner; R. F. Singer

2011-01-01

22

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

Microsoft Academic Search

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

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

2000-01-01

23

The structures of fully eutectic aluminium-silicon alloy castings  

Microsoft Academic Search

Strontium-modified aluminium alloys containing 14 to 15 wt% silicon were cast with fully eutectic structures by using heated moulds and high-purity materials. In alloys containing the additional elements magnesium, copper or nickel, a distinct eutectic colony structure was evident outlined by intermetallic compounds. At the edges of the castings the eutectic colony structures and the aluminium grains (revealed by anodizing)

T. B. Abbott; B. A. Parker

1990-01-01

24

Aluminium in Transport  

NSDL National Science Digital Library

A concise fact sheet on aluminum use in transport by the European Aluminium Association (EAA). Topics include applications (auto, air, marine, and rail), benefits, economic role, energy consumption, history, and sustainability.

European Aluminium Association (EAA)

25

Aluminium carbide formation in interpenetrating graphite\\/aluminium composites  

Microsoft Academic Search

We have produced interpenetrating graphite\\/aluminium composites by gas pressure infiltration of aluminium alloys with varying silicon content into porous graphite preforms. Infiltration experiments at 750°C have shown that a silicon content of up to 18wt.% can reduce the formation of aluminium carbide but cannot completely deter it. Optical and scanning electron microscopy revealed numerous lath-like interfacial aluminium carbide crystals in

T. Etter; P. Schulz; M. Weber; J. Metz; M. Wimmler; J. F. Löffler; P. J. Uggowitzer

2007-01-01

26

Aluminium and human breast diseases.  

PubMed

The human breast is exposed to aluminium from many sources including diet and personal care products, but dermal application of aluminium-based antiperspirant salts provides a local long-term source of exposure. Recent measurements have shown that aluminium is present in both tissue and fat of the human breast but at levels which vary both between breasts and between tissue samples from the same breast. We have recently found increased levels of aluminium in noninvasively collected nipple aspirate fluids taken from breast cancer patients (mean 268 ± 28 ?g/l) compared with control healthy subjects (mean 131 ± 10 ?g/l) providing evidence of raised aluminium levels in the breast microenvironment when cancer is present. The measurement of higher levels of aluminium in type I human breast cyst fluids (median 150 ?g/l) compared with human serum (median 6 ?g/l) or human milk (median 25 ?g/l) warrants further investigation into any possible role of aluminium in development of this benign breast disease. Emerging evidence for aluminium in several breast structures now requires biomarkers of aluminium action in order to ascertain whether the presence of aluminium has any biological impact. To this end, we report raised levels of proteins that modulate iron homeostasis (ferritin, transferrin) in parallel with raised aluminium in nipple aspirate fluids in vivo, and we report overexpression of mRNA for several S100 calcium binding proteins following long-term exposure of MCF-7 human breast cancer cells in vitro to aluminium chlorhydrate. PMID:22099158

Darbre, P D; Pugazhendhi, D; Mannello, F

2011-11-01

27

Dietary exposure to aluminium of the Hong Kong population.  

PubMed

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

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

2010-04-01

28

Aluminium phosphide poisoning  

PubMed Central

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.

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

2006-01-01

29

In situ synthesis of porous ceramics with a framework structure of aluminium borate whisker  

Microsoft Academic Search

New porous ceramics with a framework structure of aluminium borate (9Al2O3 · 2B2O3) whiskers, in which the whiskers are distributed uniformly and randomly, can be synthesized in situ by firing of a green powder compact of a mixture of aluminium hydroxide, boric acid and an additive of nickel oxide above 1100°C. During firing, the whiskers of aluminium borate grow in

J. X. Li; T. Narita; J. Ogawa; M. Wadasako

1998-01-01

30

Early stages of fatigue damage in aluminium and aluminium alloys  

Microsoft Academic Search

In this paper fatigue damage initiation is considered as both microcrack nucleation from microheterogeneities within fatigued material and microcrack growth over distances corresponding to the size of the microstructure. A brief review of the literature shows that, depending on fatigue conditions and microstructure three different types of nucleation sites exist in aluminium and aluminium alloys : slip bands, grain boundaries

R. FOUGERES

1993-01-01

31

Static crushing of square aluminium extrusions with aluminium foam filler  

Microsoft Academic Search

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

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

1999-01-01

32

The interaction between indium atoms and vacancies in dilute aluminium-indium alloys  

Microsoft Academic Search

The effect of very small additions of indium on the decay of quenched-in vacancies at 0°c in aluminium is studied by high precision electrical resistivity measurements. The extent of the observed resistivity decrease in the alloy on ageing with respect to that in pure aluminium is used as a measure of the strength of binding between indium atoms and vacancies.

W. J. Plumbridge

1969-01-01

33

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 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,

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

2003-01-01

34

Comparison of the x-ray attenuation properties of breast calcifications, aluminium, hydroxyapatite and calcium oxalate  

NASA Astrophysics Data System (ADS)

Aluminium is often used as a substitute material for calcifications in phantom measurements in mammography. Additionally, calcium oxalate, hydroxyapatite and aluminium are used in simulation studies. This assumes that these materials have similar attenuation properties to calcification, and this assumption is examined in this work. Sliced mastectomy samples containing calcification were imaged at ×5 magnification using a digital specimen cabinet. Images of the individual calcifications were extracted, and the diameter and contrast of each calculated. The thicknesses of aluminium required to achieve the same contrast as each calcification when imaged under the same conditions were calculated using measurements of the contrast of aluminium foils. As hydroxyapatite and calcium oxalate are also used to simulate calcifications, the equivalent aluminium thicknesses of these materials were also calculated using tabulated attenuation coefficients. On average the equivalent aluminium thickness was 0.85 times the calcification diameter. For calcium oxalate and hydroxyapatite, the equivalent aluminium thicknesses were 1.01 and 2.19 times the thickness of these materials respectively. Aluminium and calcium oxalate are suitable substitute materials for calcifications. Hydroxyapatite is much more attenuating than the calcifications and aluminium. Using solid hydroxyapatite as a substitute for calcification of the same size would lead to excessive contrast in the mammographic image.

Warren, L. M.; Mackenzie, A.; Dance, D. R.; Young, K. C.

2013-04-01

35

Comparison of the x-ray attenuation properties of breast calcifications, aluminium, hydroxyapatite and calcium oxalate.  

PubMed

Aluminium is often used as a substitute material for calcifications in phantom measurements in mammography. Additionally, calcium oxalate, hydroxyapatite and aluminium are used in simulation studies. This assumes that these materials have similar attenuation properties to calcification, and this assumption is examined in this work. Sliced mastectomy samples containing calcification were imaged at ×5 magnification using a digital specimen cabinet. Images of the individual calcifications were extracted, and the diameter and contrast of each calculated. The thicknesses of aluminium required to achieve the same contrast as each calcification when imaged under the same conditions were calculated using measurements of the contrast of aluminium foils. As hydroxyapatite and calcium oxalate are also used to simulate calcifications, the equivalent aluminium thicknesses of these materials were also calculated using tabulated attenuation coefficients. On average the equivalent aluminium thickness was 0.85 times the calcification diameter. For calcium oxalate and hydroxyapatite, the equivalent aluminium thicknesses were 1.01 and 2.19 times the thickness of these materials respectively. Aluminium and calcium oxalate are suitable substitute materials for calcifications. Hydroxyapatite is much more attenuating than the calcifications and aluminium. Using solid hydroxyapatite as a substitute for calcification of the same size would lead to excessive contrast in the mammographic image. PMID:23470559

Warren, L M; Mackenzie, A; Dance, D R; Young, K C

2013-04-01

36

Magnesium aluminium chromite.  

PubMed

The cation distribution in a natural magnesium aluminium chromite spinel (cubic, space group Fd-3m), Al(0.41)Cr(1.42)Fe(0.65)Mg(0.4)O(4), was determined by electron-microprobe analysis, Mossbauer spectroscopy and single-crystal X-ray analysis. Several structural models of the octahedral and tetrahedral cation distributions were tested; the most probable is (Mg(0.40(11))(2+),Al(0.28(5))(3+),Fe(0.39(4))(2+))[Al(0.13(5))(3+),Cr(1.42(6))(3+),Fe(0.26(4))(3+),Phi(0.19)]O(4)(2-), where (...) and [...] represent the tetrahedral and octahedral sites, respectively, and Phi represents a vacancy. PMID:15750218

Santos, Joab S; Doriguetto, Antônio C; Fernandes, Nelson G

2005-03-01

37

Self diffusion in liquid aluminium  

Microsoft Academic Search

Here we report temperature dependent self-diffusion coefficients of liquid aluminium measured on absolute scale by using incoherent quasielastic neutron scattering at temperatures of 980K, 1020K, and 1060K. Aluminium self-diffusion coefficients follow an Arrhenius law with an activation energy of 280±70 meV. The Sutherland-Einstein equation relating viscosity to the diffusion coefficient well captures the temperature dependence and absolute values of the

F Kargl; H Weis; T Unruh; A Meyer

2012-01-01

38

Aluminium recycling and environmental issues of salt slag treatment.  

PubMed

Environmental friendly recycling is the trend toward total recycling of aluminium metal. In the secondary aluminium industry, due to the complexity of compositions and contaminants in the various types of aluminium scraps, an understanding of the behavior of different scraps during melting is crucial in the recycling process. Salt slags are the byproducts of the secondary aluminium industry, which should be recycled and processed in a proper way by taking the environmental impact into consideration. This article provides qualitative assessment on 10 different commercial aluminium scraps for their relative recyclability via well-designed and controlled laboratory experiments. It confirms that more nonmetallic contaminants, smaller size, and higher ratio of surface area to body volume generally lead to a lower metal recovery. Recycling the scraps with lower recyclability normally generates more salt slags. High slag viscosity leads to more fine aluminum metal entrapped in the salt slag and thus increases the load of salt slag recycling. It was found that viscosity of the salt flux is increased with the amount of entrapped nonmetallic components, which affect the settling of heavier materials. In addition, the slag samples from the melting tests were leached and analyzed to evaluate the behavior of carbon containing scrap. The elevated carbon content in the scrap resulted in more carbide formation in salt slags and thus more methane generation in salt slag recycling with a higher environmental impact. PMID:16194908

Xiao, Yanping; Reuter, Markus A; Boin, Udo

2005-01-01

39

Laser pressure welding of aluminium and galvannealed steel  

Microsoft Academic Search

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

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

2009-01-01

40

Crushing of axially compressed steel tubes filled with aluminium foam  

Microsoft Academic Search

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

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

1997-01-01

41

Indentation tests of aluminium honeycombs  

NASA Astrophysics Data System (ADS)

Aluminium honeycomb is a type of cellular material which has high strength to weigh ratio and is a good energy absorber. They are used as structural components in various engineering applications. Comprehensive study has been conducted on the compressive behavior of aluminium honeycombs. However, the research of aluminium honeycombs subjected to other type of loading, such as indentation, is still limited. In this paper, quasi-static and dynamic indentation tests were conducted to study the deformation and energy absorption of three types of HEXCELL® aluminium honeycombs with different cell sizes and cell wall thicknesses. Quasi-static tests were conducted by using a universal MTS machine at velocities of 0.05 mm/s, 0.5 mm/s and 5 mm/s, respectively. Dynamic tests were conducted by using a high speed INSTRON machine at a velocity of 5 m/s. Force-displacement curves were plotted in which the total energy absorbed was calculated. The deformation of aluminium honeycombs in indentation tests includes the compression of honeycomb cells under the indenter and tearing of honeycomb cell walls along the indenter edges. The energy dissipated in compression and tearing were calculated and discussed. The effects of cell size, cell wall thickness and loading velocity or strain rate on the plateau stress and energy absorption were analyzed.

Ashab, A.; Wong, Y. C.; Lu, G.; Ruan, D.

2013-07-01

42

Spot welding of aluminium clad steel to steel or aluminium: Joining steel to aluminium with an intermediate layer (1st report)  

Microsoft Academic Search

This paper describes an investigation of the resistance spot weldability of aluminium clad steel sheet to steel or aluminium sheet as well as joining of a steel to an aluminium sheet with an aluminium clad steel sheet as an intermediate layer. The clad steel sheet was produced by hot?rolling of steel and aluminium sheet by a direct resistance heating process.

H. Oikawa; T. Saito; T. Yoshimura; T. Nagase; T. Kiriyama

1996-01-01

43

Benchmarking aluminium die casting operations  

Microsoft Academic Search

Increasing demand in world automotive markets for aluminium die cast components is creating significant opportunities and challenges for the Australian industry, which is positioning itself as a global player. To meet these challenges, the industry is continuously seeking to improve its overall resource efficiency that can result in the reduction of cost and impact on green house gas (GHG) emissions.

A. Tharumarajah

2008-01-01

44

Aluminium toxicity in chronic renal insufficiency  

SciTech Connect

Aluminium is a ubiquitous element in the environment and has been demonstrated to be toxic, especially in individuals with impaired renal function. Not much is known about the biochemistry of aluminium and the mechanisms of its toxic effects. Most of the interest in aluminium has been in the clinical setting of the hemodialysis unit. Here aluminium toxicity occurs due to contamination of dialysis solutions, and treatment of the patients with aluminium-containing phosphate binding gels. Aluminium has been shown to be the major contributor to the dialysis encephalopathy syndrome and an osteomalacic component of dialysis osteodystrophy. Other clinical disturbances associated with aluminium toxicity are a microcytic anemia and metastatic extraskeletal calcification. Aluminium overload can be treated effectively by chelation therapy with desferrioxamine and hemodialysis. Aluminium is readily transferred from the dialysate to the patient's -bloodstream during hemodialysis. Once transferred, the aluminium is tightly bound to non-dialysable plasma constituents. Very low concentrations of dialysate aluminium in the range of 10-15 micrograms/l are recommended to guard against toxic effects. Very few studies have been directed towards the separation of the various plasma species which bind eluminium. Gel filtration chromatography has been used to identify five major fractions, one of which is of low molecular weight and the others appear to be protein-aluminium complexes. Recommendations on aluminium monitoring have been published and provide safe and toxic concentrations. Also, the frequency of monitoring has been addressed. Major problems exist with the analytical methods for measuring aluminium which result from inaccurate techniques and contamination difficulties. 136 references.

Savory, J.; Bertholf, R.L.; Wills, M.R.

1985-08-01

45

Precipitate strengthening of nanostructured aluminium alloy.  

PubMed

Grain boundaries and precipitates are the major microstructural features influencing the mechanical properties of metals and alloys. Refinement of the grain size to the nanometre scale brings about a significant increase in the mechanical strength of the materials because of the increased number of grain boundaries which act as obstacles to sliding dislocations. A similar effect is obtained if nanoscale precipitates are uniformly distributed in coarse grained matrix. The development of nanograin sized alloys raises the important question of whether or not these two mechanisms are "additive" and precipitate strengthening is effective in nanostructured materials. In the reported work, hydrostatic extrusion (HE) was used to obtain nanostructured 7475 aluminium alloy. Nanosized precipitates were obtained by post-HE annealing. It was found that such annealing at the low temperatures (100 degrees C) results in a significant increase in the microhardness (HV0.2) and strength of the nanostructured 7475 aluminium alloy. These results are discussed in terms of the interplay between the precipitation and deformation of nanocrystalline metals. PMID:23421286

Wawer, Kinga; Lewandowska, Malgorzata; Kurzydlowski, Krzysztof J

2012-11-01

46

Aluminium compounds for use in vaccines.  

PubMed

Aluminium adjuvants are the most widely used adjuvants in both human and veterinary vaccines. These adjuvants have been used in practical vaccination for more than 60 years and are generally recognized as safe and as stimulators of Th2 immunity. The present review gives a short introduction to the pioneering research at the start of the use of aluminium compounds as adjuvants, including references on the chemistry of these compounds. Analytical methods for identifying the most commonly used aluminium compounds, such as boehmite and aluminium hydroxyphosphate, are mentioned. Emphasis is placed on the important factors for antigen adsorption and on the latest work using gene-deficient mice in the research of the mechanism of aluminium adjuvants in terms of cytokine and T-cell subset stimulation. Key references on the ability of aluminium adjuvants to stimulate IgE and also in vivo clearing of aluminium adjuvants are discussed. Furthermore, the review addresses the issue of local reactions in the context of injection route and local tissue disturbance. Possible new applications of aluminium adjuvants in, for example, combined aluminium-adsorbed protein and DNA oligonucleotide vaccines as well as the possible use of aluminium adjuvants in combination with IL-12 to stimulate Th1-type immune responses are mentioned. PMID:15479435

Lindblad, Erik B

2004-10-01

47

Aluminium electrodeposition under ambient conditions.  

PubMed

The electrodeposition of aluminium is demonstrated using a eutectic mixture of aluminium chloride and urea. The mixture is shown to be conducting through the formation of both cationic ([AlCl2·urean](+)) and anionic (AlCl4(-)) species and electrodeposition is achieved through the cationic species. The use of a biphasic system with the ionic liquid and a protective hydrocarbon layer allows metal deposition to be carried out in an environment with ambient moisture without the need for a glove box. A direct comparison is made between the AlCl3:urea and imidazolium chloride:AlCl3 systems and the differences in speciation and mass transport manifest themselves in different deposit morphologies. Brighteners which work in the chloroaluminate system such as toluene and LiCl are shown to be ineffective in the urea based system and the reasons for these differences are ascribed to the mechanism of the anodic reaction which is rate limiting. PMID:24916113

Abbott, Andrew P; Harris, Robert C; Hsieh, Yi-Ting; Ryder, Karl S; Sun, I-Wen

2014-06-25

48

Aluminium in foodstuffs and diets in Sweden.  

PubMed

The levels of aluminium have been determined in a number of individual foodstuffs on the Swedish market and in 24 h duplicate diets collected by women living in the Stockholm area. The results show that the levels in most foods are very low and that the level in vegetables can vary by a factor 10. Beverages from aluminium cans were found to have aluminium levels not markedly different from those in glass bottles. Based on the results of the analysis of individual foods, the average Swedish daily diet was calculated to contain about 0.6 mg aluminium, whereas the mean content of the collected duplicate diets was 13 mg. A cake made from a mix containing aluminium phosphate in the baking soda was identified as the most important contributor of aluminium to the duplicate diets. Tea and aluminium utensils were estimated to increase the aluminium content of the diets by approximately 4 and 2 mg/day, respectively. The results also indicate that a considerable amount of aluminium must be introduced from other sources. PMID:1542992

Jorhem, L; Haegglund, G

1992-01-01

49

Aluminium migration to orange juice in laminated paperboard packages  

Microsoft Academic Search

The migration of aluminium (Al) from aseptic laminated paperboard packages was studied by monitoring the Al content of orange juice (plain juice, no additives) filled into such packages and stored at ambient temperature (23°C) for up to 1 year. Analytical procedure includes MW-assisted digestion of orange juice with concentrated nitric acid followed by determination of Al concentration by double-focusing sector

Ilia Rodushkin; Astrid Magnusson

2005-01-01

50

Shear Strength of Single Lap Joint Aluminium-Thermoplastic Natural Rubber (Al-TPNR) Laminated Composite  

NASA Astrophysics Data System (ADS)

In this work, we studied the effect of surface treatment on the aluminium surface and a coupling agent to improve adhesion between aluminium with organic polymer. Thermoplastic natural rubber (TPNR) matrix was prepared by melt blending of natural rubber (NR), liquid natural rubber (LNR) compatibilizer, linear low density polyethylene (LLDPE) and polyethylene grafted maleic anhydride (PE-g-MAH). The PEgMAH concentration used was varied from 0% - 25%. In addition, the aluminium surface was pre-treated with 3-glycidoxy propyl trimethoxy silane (3-GPS) to enhance the mechanical properties of laminated composite. It was found that the shear strength of single lap joint Al-TPNR laminated composite showing an increasing trend as a function of PE-g-MAH contents for the 3-GPS surface treated aluminium. Moreover, the scanning electron microscope (SEM) revealed that the strength improvement was associated with the chemical state of the compound involved.

Muzakkar, M. Z.; Ahmad, S.; Yarmo, M. A.; Jalar, A.; Bijarimi, M.

2013-04-01

51

Caractérisation d'alliages aluminium-silicium-nickel déposés par rechargement laser sur alliage d'aluminium  

NASA Astrophysics Data System (ADS)

The modifications brought to aluminium by addition of silicon and nickel are investigated after a laser cladding process by a Nd: YAG laser. Samples are characterized using microscopic examination, X-ray diffraction and micro-hardness measurement. The optimum composition (Al 22Si 27Ni (wt.%)) is selected for its fine and homogeneous microstructure: presence of equiaxis precipitates (Si) and AIN (average size of 20 and 5 ?m) and its high hardness (412 HV5). Les modifications apportées à l'aluminium par addition de silicium et de nickel ont été étudiées après rechargement laser réalisé grâce à un laser Nd : YAG. Les échantillons ont été caractérisés par microscopie optique, diffraction des rayons X et macro-indentation. La composition optimale (Al 22Si 27Ni (wt.%)) a été retenue pour sa microstructure fine et homogène : présence des précipités équiaxes (Si) et Al3Ni (dimensions moyennes de 20 et 5 ?m), ainsi que pour sa dureté élevée : 412 HV5.

Dubourg, L.; Hlawka, F.; Cornet, A.

2002-07-01

52

Stress-corrosion Cracking of Aluminium  

Microsoft Academic Search

ALUMINIUM forging alloys used in aerospace technology have, on occasion, suffered catastrophic failure as a result of stress-corrosion cracking. Study of this problem by thin-film transmission electron microscopy has disclosed a fundamental relationship between those aluminium structures within the same alloy (achieved by heat treating) that are highly sensitive to stress-corrosion cracking and those that are immune.

A. J. Jacobs

1966-01-01

53

DAMPING BEHAVIOUR OF CAST AND SINTERED ALUMINIUM  

Microsoft Academic Search

Estimating damping in structures made of different materials and processes still remains as one of the biggest challenges. Aluminium is one such pioneer material which is being used extensively in aerospace, automotive and the manufacturing industry. Aluminium components are mainly manufactured by traditional casting and powder metallurgy process. The main objective of this paper is to estimate the damping ratio

Abhinav Alva; Vijay Desai

54

Heat of Formation of Aluminium Chloride.  

National Technical Information Service (NTIS)

By chlorinating aluminium under pressure in a glass combustion vessel, a value of -168.8 kcal/mole was obtained for the standard heat of formation of aluminium chloride. The total error is considered to be less than plus or minus 0.20 kcal.

P. Gross C. Hayman

1967-01-01

55

Structural behaviour of aluminium bridge deck panels  

Microsoft Academic Search

The use of lightweight bridge decks made of FRP composites or aluminium alloys is particularly effective for replacing deteriorated bridge decks. Therefore a research program has been undertaken to develop and implement an innovative aluminium bridge deck system, which would be applicable and realizable in domestic conditions. Several service load and ultimate load tests have been carried out on the

Tomasz W. Siwowski

2009-01-01

56

Feasibility of warm drawing of aluminium products  

Microsoft Academic Search

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

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

2001-01-01

57

Analysis of the dynamics of liquid aluminium: recurrent relation approach  

NASA Astrophysics Data System (ADS)

By use of the recurrent relation approach (RRA) we study the microscopic dynamics of liquid aluminium at T = 973 K and develop a theoretical model which satisfies all the corresponding sum rules. The investigation covers the inelastic features as well as the crossover of our theory into the hydrodynamical and the free-particle regimes. A comparison between our theoretical results with those following from a generalized hydrodynamical approach is also presented. In addition to this we report the results of our molecular dynamics simulations for liquid aluminium, which are also discussed and compared to experimental data. The results obtained reveal (i) that the microscopical dynamics of density fluctuations is defined mainly by the first four even frequency moments of the dynamic structure factor, and (ii) the inherent relation of the high-frequency collective excitations observed in experimental spectra of dynamic structure factor S(k,?) with the two-, three- and four-particle correlations.

Mokshin, A. V.; Yulmetyev, R. M.; Khusnutdinoff, R. M.; Hänggi, P.

2007-01-01

58

Surface mechanical behaviour of composite Ni-P-fly ash/zincate coated aluminium alloy  

NASA Astrophysics Data System (ADS)

Ni-P-fly ash coatings were produced on zincate coated 5083 wrought aluminium alloy substrates with the aid of an electroless deposition technique. Structural and chemical characterization of the produced coatings was performed with the aid of X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron dispersive X-ray analysis (EDS) techniques. The Ni-P-fly ash coating was found to consist of an amorphous Ni-P matrix with dispersed fly ash particles. The wear resistance of the Ni-P-fly ash coating on zincate treated aluminium alloy was observed to be higher than that of the bare aluminium alloy, when sliding against a stainless steel counterface. In addition, the adhesion between the Ni-P-fly ash/zincate coating and the aluminium alloy substrate was also studied with a scratch testing apparatus. The adhesion strength of Ni-P-fly ash/zincate coating on the aluminium alloy substrate was observed to be higher in comparison to the Ni-P/zincate coating on the same aluminium alloy.

Panagopoulos, C. N.; Georgiou, E. P.

2009-04-01

59

Oxidative stress and mitochondrial dysfunction in aluminium neurotoxicity and its amelioration: a review.  

PubMed

Aluminium is light weight and toxic metal present ubiquitously on earth which has gained considerable attention due to its neurotoxic effects. The widespread use of products made from or containing aluminium is ensuring its presence in our body. There is prolonged retention of a fraction of aluminium that enters the brain, suggesting its potential for accumulation with repeated exposures. There is no known biological role for aluminium within the body but adverse physiological effects of this metal have been observed in mammals. The generation of oxidative stress may be attributed to its toxic consequences in animals and humans. The oxidative stress has been implicated in pathogenesis of various neurodegenerative conditions including Alzheimer's disease and Parkinson's disease. Though it remains unclear whether oxidative stress is a major cause or merely a consequence of cellular dysfunction associated with neurodegenerative diseases, an accumulating body of evidence implicates that impaired mitochondrial energy production and increased mitochondrial oxidative damage is associated with the pathogenesis of neurodegenerative disorders. Being involved in the production of reactive oxygen species, aluminium may impair mitochondrial bioenergetics and may lead to the generation of oxidative stress. In this review, we have discussed the oxidative stress and mitochondrial dysfunctions occurring in Al neurotoxicity. In addition, the ameliorative measures undertaken in aluminium induced oxidative stress and mitochondrial dysfunctions have also been highlighted. PMID:24560992

Kumar, Vijay; Gill, Kiran Dip

2014-03-01

60

Development of multilayer coatings for forming dies and tools of aluminium alloy from liquid state  

NASA Astrophysics Data System (ADS)

In this work, a nanocomposite (Cr,Al)xN1-x/Si3N4 coating system was deposited on H11 hot work tool steel, using the Lateral Arc Rotating Cathodes (LARC®) deposition system and modulating the chemical composition of the chromium and aluminium-silicon content. Structural characterizations were performed using scanning electron microscopy, equipped with energy dispersive spectroscopy probe, and applying x-ray diffraction, for the evaluation of phase constitution and crystallite size. In addition to the structural features, the coatings' resistance to cyclic immersions in molten aluminium alloy was evaluated. The deposited CrAlSiN coatings exhibited an fcc-Cr1-xAlxN type structure with different aluminium contents, which directly influence hardness and wear and fatigue resistance in cyclic immersion tests. The main failure modes that occurred on the coatings' surface were soldering and thermal fatigue cracks mainly in the form of heat checks. The aluminium rich coatings were able to withstand about 15 000 cycles, whereas the decrease in the aluminium content in the coatings results in a decrease in the resistance to the immersion in molten aluminium bath. It is worthwhile to note that uncoated H11, subjected to similar testing conditions, withstood at maximum 5000 cycles.

Torres, E.; Ugues, D.; Brytan, Z.; Perucca, M.

2009-05-01

61

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

PubMed Central

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.

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

1996-01-01

62

Galvanised steel to aluminium joining by laser and GTAW processes  

Microsoft Academic Search

A new means of assembling galvanised steel to aluminium involving a reaction between solid steel and liquid aluminium was developed, using laser and gas tungsten arc welding (GTAW) processes. A direct aluminium melting strategy was investigated with the laser process, whereas an aluminium-induced melting by steel heating and heat conduction through the steel was carried out with the GTAW process.

G. Sierra; P. Peyre; F. Deschaux Beaume; D. Stuart; G. Fras

2008-01-01

63

Aluminium in Biological Environments: A Computational Approach  

PubMed Central

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.

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

2014-01-01

64

Modelling More Sustainable Aluminium (4 pp)  

Microsoft Academic Search

Goal, Scope and Background   This case study describes the development and utilization of a global, quantitative model of current and projected aluminium\\u000a and life cycle inventory mass flows. The model and key results were developed to be shared with global aluminium industry\\u000a technical experts, executives, and external stakeholders to better understand potential paths to more global sustainable aluminium.\\u000a \\u000a \\u000a \\u000a \\u000a Methods   The

Kenneth J. Martchek

2006-01-01

65

Aluminium toxicity and nodulation of Trifolium repens  

Microsoft Academic Search

Summary  Effects of aluminium on theTrifolium repens var Huia-Rhizobium trifolii strain HP3 symbiosis were studied using an axenic solution-culture system. With, 10 ?M phosphate, 50 ?M aluminium reduced or inhibited root elongation at pH<5.0, root hair formation at pH< 5.0–5.5, and Rhizobium multiplication\\u000a in the rhizosphere and nodule formation at pH<6.0. In the absence of aluminium, root elongation and root hair

M. Wood; J. E. Cooper; A. J. Holding

1984-01-01

66

Recycling of aluminium scrap for secondary Al-Si alloys.  

PubMed

An increasing amount of recycled aluminium is going into the production of aluminium alloy used for automotive applications. In these applications, it is necessary to control and remove alloy impurities and inclusions. Cleaning and fluxing processes are widely used during processing of the alloys for removal of inclusions, hydrogen and excess of magnesium. These processes use salt fluxes based in the system NaCl-KCl, injection of chlorine or mixture of chlorine with an inert gas. The new systems include a graphite wand and a circulation device to force convection in the melt and permit the bubbling and dispersion of reactive and cleaning agents. This paper discusses the recycling of aluminium alloys in rotary and reverberatory industrial furnaces. It focuses on the removal of magnesium during the melting process. In rotary furnaces, the magnesium lost is mainly due to the oxidation process at high temperatures. The magnesium removal is carried out by the reaction between chlorine and magnesium, with its efficiency associated to kinetic factors such as concentration of magnesium, mixing, and temperature. These factors are also related to emissions generated during the demagging process. Improvements in the metallic yield can be reached in rotary furnaces if the process starts with a proper salt, with limits of addition, and avoiding long holding times. To improve throughput in reverberatories, start the charging with high magnesium content material and inject chlorine gas if the molten metal is at the right temperature. Removal of magnesium through modern technologies can be efficiently performed to prevent environmental problems. PMID:20837560

Velasco, Eulogio; Nino, Jose

2011-07-01

67

Elevated brain aluminium and early onset Alzheimer's disease in an individual occupationally exposed to aluminium: a case report  

PubMed Central

Introduction Aluminium is a known neurotoxin and occupational exposure to aluminium has been implicated in neurological disease including Alzheimer’s disease. Here we present the first comprehensive and unequivocal data demonstrating significantly elevated brain aluminium content in an individual occupationally exposed to aluminium. Case presentation A 66-year-old Caucasian man who died with Alzheimer’s disease showed significantly elevated brain aluminium content, 2.98 (2.73) ?g/g dry weight, n?=?46, following occupational exposure to aluminium over a period of 8 years. Conclusions That the individual developed an early onset aggressive form of Alzheimer’s disease suggests a role for aluminium in disease aetiology. That the exposure to aluminium was through occupational exposure to aluminium dust suggests a prominent role for the olfactory system and lungs in the accumulation of aluminium in the brain.

2014-01-01

68

Novel method for joining CFRP to aluminium  

NASA Astrophysics Data System (ADS)

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.

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

69

Disagglomeration in thixoformed wrought aluminium alloy 2014  

Microsoft Academic Search

Thixoforming is a type of semi-solid metal processing, which involves the processing of alloys in the semi-solid state. Disagglomeration of solid globules during thixoforming of wrought aluminium alloy 2014 was investigated by electron back-scatter diffraction. The recrystallisation and partial melting route was used to produce the thixotropic feedstock for thixoforming. The starting material was commercially extruded wrought aluminium alloy 2014

D. Liu; H. V. Atkinson; R. L. Higginson

2005-01-01

70

Mechanochemically activated nano-aluminium: Oxidation behaviour  

Microsoft Academic Search

Nanocrystalline aluminium powder has been prepared by high-energy ball milling of flaked micron-sized aluminium powder in the presence of 10 wt% of graphite under argon atmosphere. The structure and chemical composition of as-prepared nanocomposites and the their thermally induced changes are studied by X-ray diffraction (XRD), transmission electron microscopy (TEM), and simultaneous TG-DTA technique (SDT). TEM studies reveal that the

A. Pivkina; A. Streletskii; I. Kolbanev; P. Ul'yanova; Yu. Frolov; P. Butyagin; J. Schoonman

2004-01-01

71

Joining of Aluminium Metal Matrix Composites  

Microsoft Academic Search

Aluminium metal matrix composites (AlMMCs) offer several advantages relative to monolithic aluminium alloys such as high stiffness, strength, wear resistance, low thermal expansion coefficient, etc. However, despite considerable improvements in developing AlMMCs, the lack of reliable joining methods restrict their greater application. Fusion welding of AlMMCs has not proved successful because high temperature nature of the process normally causes unfavorable

Tapan Kumar Pal

2005-01-01

72

Laser-modified aluminium surfaces with iron  

Microsoft Academic Search

Possible improvements in the mechanical properties of surface-coated aluminium have been investigated. Aluminium plasma sprayed with iron powder was processed using two different laser-beam settings (integrated and defocused) with varying processing parameters. Mechanical and microstructural characterizations of the specimens revealed great differences between the two laser-beam settings. The defocused laser beam showed a clear improvement of hardness which was not

L. Gjønnes; A. Olsen

1994-01-01

73

Standardization and validation of a new atomic absorption spectroscopy technique for determination and quantitation of Aluminium adjuvant in immunobiologicals  

Microsoft Academic Search

In the present study, Aluminium quantification in immunobiologicals has been described using atomic absorption spectroscopy (AAS) technique. The assay was found to be linear in 25–125?g\\/ml Aluminium range. The procedure was found to be accurate for different vaccines with recoveries of external additions ranging between 93.26 and 103.41%. The mean Limit of Variation (L.V.) for both intra- and inter-assay precision

Arti Mishra; Sumir Rai Bhalla; Sameera Rawat; Vivek Bansal; Rakesh Sehgal; Sunil Kumar

2007-01-01

74

Spot welding of aluminium and steel sheet with an insert of aluminium clad steel sheet: Dissimilar metal joining of aluminium and steel sheet (1st Report)  

Microsoft Academic Search

This paper describes an investigation of the dissimilar metal spot welding of aluminium and steel sheet with an aluminium clad steel sheet insert. The study relates to application of this system in automotive fabrication in an effort to reduce motor vehicle weight. To ascertain the mechanical properties of the intermetallic compounds formed at the steel and aluminium bond interface, measurements

M. Yasuyama; K. Ogawa; T. Taka

1996-01-01

75

Comparative structural investigation of aluminium fluoride solvates  

NASA Astrophysics Data System (ADS)

To get some insight by conclusions of analogy into the drying process of alcoholic aluminium fluoride sol-gels [AlF 3/(ROH) x], the structures of ?- and ?-AlF 3?3H 2O as well as of the nonahydrate AlF 3?9H 2O are reinvestigated and discussed based on X-ray single crystal structural data. In addition, neutron diffraction experiments of the latter allowed the refinement of proton positions. In accordance with crystal structures, low-temperature solid state 27Al-, 1H- and 19F-MAS NMR spectra convincingly confirm the structural similarity between ?-AlF 3?3H 2O and AlF 3?9H 2O, while the ?-phase material is structurally different forming chain structures. Thermal analysis of AlF 3/(ROH) x gave evidence for discrete AlF 3:ROH ratios of only 1:0.45 and 1:0.1, and solution NMR showed some similarities between aqueous and alcoholic systems.

Kemnitz, E.; Groß, U.; Rüdiger, St.; Scholz, G.; Heidemann, D.; Troyanov, S. I.; Morosov, I. V.; Lemée-Cailleau, M.-H.

2006-12-01

76

Self Healing in Aluminium Alloys  

NASA Astrophysics Data System (ADS)

Self healing is a key property of biological materials, examples being the autonomous repair of fractured bones or torn skin tissue, as is discussed in other chapters of this book. More than a century ago, principles were developed defining the reconstitution of fractured bone in vivo which stated that, in essence, material dissolved from where it was not required was redeposited to where it was required as a response to mechanical stimuli and damage. As far as metals and other inanimate materials are concerned, it is well known that damage to oxide films, which normally protect the surfaces of metals such as aluminium (Al) and titanium (Ti) from corrosion, can be repaired by reoxidation in air, which can be seen as a form of self-repair. Now attention is being directed to processes that may possibly heal defects, such as cracks, which can develop in the interior of materials during manufacture, or when they are in service. Such self healing processes may then allow failures to be averted and the useful lives of components and structures to be extended.

Lumley, Roger

77

Complexometric determination of aluminium in iron ore, sinter, concentrates and agglomerates.  

PubMed

A method for the complexometric determination of aluminium in iron ore, sinter, concentrates and agglomerates encountered in international trade is described. The sample is fused in a zirconium crucible with a mixed flux of sodium carbonate and sodium peroxide. The fused mass is completely soluble in hydrochloric acid. The R(2)O(3) oxides are then precipitated with ammonia and redissolved in hydrochloric acid. Elements such as iron, titanium and zirconium are separated from aluminium by solvent extraction with cupferron and chloroform. After removal of traces of organic matter from the aqueous phase, the solution is treated with an excess of EDTA, which is then back-titrated with zinc solution (Xylenol Orange as indicator). Addition of ammonium fluoride then releases EDTA equivalent to the aluminium and this is titrated with zinc solution. The method is rapid. The precision and accuracy are excellent, and the results comparable with those obtained by the referee method. PMID:18962398

Bhargava, O P

1979-02-01

78

Benzaldehyde, 2-hydroxybenzoyl hydrazone derivatives as inhibitors of the corrosion of aluminium in hydrochloric acid.  

PubMed

The effect of benzaldehyde, 2-hydroxybenzoyl hydrazone derivatives on the corrosion of aluminium in hydrochloric acid has been investigated using thermometric and polarization techniques. The inhibitive efficiency ranking of these compounds from both techniques was found to be: 2>3>1>4. The inhibitors acted as mixed-type inhibitors but the cathode is more polarized. The relative inhibitive efficiency of these compounds has been explained on the basis of structure of the inhibitors and their mode of interaction at the surface. Results show that these additives are adsorbed on an aluminium surface according to the Langmuir isotherm. Polarization measurements indicated that the rate of corrosion of aluminium rapidly increases with temperature over the range 30-55 degrees C both in the absence and in the presence of inhibitors. Some thermodynamic data of the adsorption process are calculated and discussed. PMID:10823698

Fouda, A S; Gouda, M M; El-Rahman, S I

2000-05-01

79

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

Microsoft Academic Search

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

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

2009-01-01

80

Aluminium and fluoride contents of tea, with emphasis on brick tea and their health implications  

Microsoft Academic Search

Tea plant takes up a large quantity of aluminium (Al) and fluoride (F) from acidic soils. It has been known that fluorosis can be developed for people who consume a large quantity of tea made from brick tea, a low quality tea consisting mainly of old tea leaves in China. In addition, it has been claimed that Alzheimer's disease (AD)

M. H Wong; K. F Fung; H. P Carr

2003-01-01

81

Surface morphology, composition and thermal behavior of tungsten-containing anodic spark coatings on aluminium alloy  

Microsoft Academic Search

Anodic spark coatings on aluminium alloy were prepared in aqueous electrolytes with sodium tungstate. The influence of boric acid addition in the electrolyte on the surface morphology, elemental and phase composition of the coatings was investigated. In both cases the coatings contained O, Al and W. The coatings obtained in electrolyte with boric acid and sodium tungstate contain also B

I. V. Lukiyanchuk; V. S. Rudnev; V. G. Kuryavyi; D. L. Boguta; S. B. Bulanova; P. S. Gordienko

2004-01-01

82

High-temperature strength of compacted sub-micrometer aluminium powder  

Microsoft Academic Search

Aluminium powders with a mean particle size of around 1?m were compacted by cold isostatic pressing (CIP) and additional forging. The specimens are characterized by hot compression tests, dilatometry and metallography. A 3D interconnected structure of alumina films <5nm in thickness is observed by transmission electron microscopy and field emission gun scanning electron microscopy; it is associated with the natural

C. Poletti; M. Balog; F. Simancik; H. P. Degischer

2010-01-01

83

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

Microsoft Academic Search

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

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

1997-01-01

84

Process and Mechanical Properties: Applicability of a Scandium modified Al-alloy for Laser Additive Manufacturing  

Microsoft Academic Search

The applicability of an aluminium alloy containing scandium for laser additive manufacturing (LAM) is considered. Modified aluminium alloys with a scandium content beyond the eutectic point offer great potential to become a high prioritized aerospace material. Depending on other alloying elements like magnesium or zirconium, strongly required weight reduction, corrosion resistance and improved strength properties of metallic light weight alloys

K. Schmidtke; F. Palm; A. Hawkins; C. Emmelmann

2011-01-01

85

Welding Metallurgy of Aluminium for Radiation Tube of Reactor.  

National Technical Information Service (NTIS)

The metallurgy of TIG weldment in aluminium alloy was examined based on physical metallurgy characteristics. The presence of weld defects have been detected by x-ray radiographic and metallographic methods. The lack of penetration in the aluminium weldmen...

Mohamad Harun Abdul Aziz Mohamad Zailee Dollah Azlan Samah Jasmin Baba

1986-01-01

86

Diffusion bonding stainless steel to alumina using aluminium interlayers  

Microsoft Academic Search

A study has been conducted to identify the effects of fabrication temperatures pressures, times and other variables on the strengths of diffusion-bonded joints between alumina and BS321 stainless steel produced using aluminium foil interlayers. The strengths of the alumina-aluminium and steel-aluminium interfaces were found to be influenced differently by some fabrication parameters, thus increasing the fabrication temperature promoted alumina-aluminium bonding

M. G. Nicholas; R. M. Crispin

1982-01-01

87

General Overview of Cold Pressure Processes for Joining Aluminium  

Microsoft Academic Search

The paper presents a brief overview on several researches developed in the Pressure Welding Laboratory, Robotics of Welding Department - Dunarea de Jos University of Galati, Romania. After the necessary Introduction in the subject, considerations on Joining Aluminium Processes Classifications are presented, including an overview on the main joining processes used for aluminium. Several aspects of Aluminium cold welding processes

Danut IORDACHESCU; Bogdan Georgescu; Mihaela IORDACHESCU

88

Further experiences with aluminium wire seals for bakeable vacuum systems  

Microsoft Academic Search

The use of aluminium cemented seals in vacuum systems has been further investigated to find the effect of the flange surface finish on the adhesion of the aluminium joint and the performance of such seals in bakeable apparatus. Aluminium wire clamped between stainless-steel flanges and baked at 300° C formed more adherent joints as the surface finish was decreased from

L. Elsworth; L. Holland; L. Laurenson

1960-01-01

89

Enhancing the formability of aluminium components via temperature controlled hydroforming  

Microsoft Academic Search

New requirements of the automotive industry, concerning lightweight and non-corroding construction, demand new production methods. Due to this the hydroforming process of aluminium alloys are of special interest. The disadvantage of aluminium alloys is the poorer formability compared to steel. A method to increase the formability of the aluminium alloys during the hydroforming process is the enhancement of the forming

Michael Keigler; Herbert Bauer; David Harrison; Anjali K. M. De Silva

2005-01-01

90

Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders  

Microsoft Academic Search

Summary accompanying the thesis: Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders by Jens de Kanter This thesis presents the investigation of the crush behaviour of both monolithic aluminium cylinders and externally fibre reinforced aluminium cylinders. The research is based on analytical work, numerical work and experimental work, which together show a complete picture of the tube axial crush

J. L. C. G. De Kanter

2006-01-01

91

Recovery of aluminium from coal ash by fluid bed chlorination  

Microsoft Academic Search

The chlorination of aluminium in coal ash was studied experimentally in a fluidized bed reactor. With carbon (fluid coke) and CO as reducing agents, about 25% of aluminium in ash could be chlorinated at above 900 C in 2 hours. Global reaction rate data for aluminium as well as iron, silicon, and titanium indicated two very distinct reaction regions. A

W. Y. Svrcek; A. K. Mehrotra; L. A. Behie; P. R. Bishnoi

1983-01-01

92

Oxidation-assisted ductility of aluminium nanowires.  

PubMed

Oxidation can drastically change mechanical properties of nanostructures that typically have large surface-to-volume ratios. However, the underlying mechanisms describing the effect oxidation has on the mechanical properties of nanostructures have yet to be characterized. Here we use reactive molecular dynamics and show that the oxidation enhances the aluminium nanowire ductility, and the oxide shell exhibits superplastic behaviour. The oxide shell decreases the aluminium dislocation nucleation stress by increasing the activation volume and the number of nucleation sites. Superplasticity of the amorphous oxide shell is due to viscous flow as a result of healing of the broken aluminium-oxygen bonds by oxygen diffusion, below a critical strain rate. The interplay between the strain rate and oxidation rate is not only essential for designing nanodevices in ambient environments, but also controls interface properties in large-scale deformation processes. PMID:24887649

Sen, Fatih G; Alpas, Ahmet T; van Duin, Adri C T; Qi, Yue

2014-01-01

93

High strain rate superplasticity of AlN particulate reinforced aluminium alloy composites  

SciTech Connect

Ceramic whisker or particulate reinforced aluminium alloy composites have a great potential for automobile engineering components, aerospace structures, semi-conductor packaging and so on, because of the composites ability to exhibit a high specific elastic modulus and specific tensile strength, excellent wear resistance and heat resistance, low thermal expansion and good dimensional stability. A serious problem involving practical application of ceramic whisker or particulate reinforced aluminium alloy composites is due to the low tensile ductility, fracture toughness at room temperature and, also, their hardness qualities that make it difficult to deform by conventional forming processing and machining by ordinary tools. It has been found, however, that aluminium alloy composites reinforced by SiC or Si[sub 3]N[sub 4] whiskers or particulates produce superplasticity at a high strain rate of about 0.1s[sup [minus]1]. Superplastic deformation mechanisms of the ceramic whisker or particulate reinforced aluminium alloy composites are fine grain boundary sliding, interfacial sliding at a liquid phase and dynamic recrystallization. An AlN particulate reinforced aluminium alloy composite exhibits a high elastic modulus and a high thermal conductivity, and their thermal expansion is similar to silicon in that the AlN particulate reinforced aluminum alloy composite is expected to apply to semi-conductor packaging in the aerospace structure. In addition, if the composite could produce superplasticity at high strain rates, the market of aerospace application for superplastic composites could be expanded. The purpose of this study is to make clear if an AlN particulate reinforced aluminium alloy composite can produce superplasticity at high strain rate and the superplastic characteristics.

Imai, T. (National Industrial Research Inst. of Nagoya (Japan)); L'Esperance, G.; Hong, B.D. (Ecole Polytechnique de Montreal, Quebec (Canada))

1994-08-01

94

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

PubMed

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

Damse, R S; Sikder, A K

2008-06-15

95

Evaluation of certain food additives and contaminants.  

PubMed

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

2013-01-01

96

Detonation Performance of Aluminium - Ammonium Nitrate Explosives  

Microsoft Academic Search

The research on an effect of aluminium contents on detonation characteristics of ammonium nitrate explosives was carried out. Measurements of detonation velocity were performed. Parameters of blast waves produced by charges of the investigated explosives detonating in an open space were measured by the use of piezoelectric gauges. Quasi-static pressure measurements were conducted in a steel chamber of 0.15 m

Józef PASZULA; Waldemar A. TRZCI?SKI

97

Electron Conditioning of Technical Aluminium Surfaces.  

National Technical Information Service (NTIS)

The effect of electron conditioning on commercially aluminium alloys 1100 and 6063 were investigated. Contrary to the assumption that electron conditioning, if performed long enough, can reduce and stabilize the SEY to low values (= 1.3, value of many pur...

F. L. Pimpec F. King R. E. Kirby

2004-01-01

98

Residual stress in 7449 aluminium alloy forgings  

Microsoft Academic Search

The through thickness residual stress distributions within three 120mm thick rectilinear forgings, made from the high strength aluminium alloy 7449 have been measured using both neutron diffraction and deep hole drilling. Neutron diffraction measurements were made on two instruments, one using a pulsed spallation neutron source, the other a steady state reactor source. Heat treatment of the forgings included a

J. S. Robinson; S. Hossain; C. E. Truman; A. M. Paradowska; D. J. Hughes; R. C. Wimpory; M. E. Fox

2010-01-01

99

The scratch behaviour of aluminium composite coatings  

Microsoft Academic Search

Wear data obtained from single and multiple scratch passes, combined with the examination of the reinforcement-matrix interfacial structure by transmission electron microscopy (TEM) and toughness measurements made on the reinforcement phase, wereused to evaluate the wear behaviour of aluminium-based composite coatings. Reinforcement properties such as reinforcement volume fraction (Vf ), size, interfacial bonding and toughness appear to be important variables

R. L. Deuis; C. Subramanian; G. P. Cavallaro

1997-01-01

100

Two-photon excitation of aluminium phthalocyanines  

SciTech Connect

A demonstration is given of the feasibility of two-photon excitation of aluminium phthalocyanine and of the pharmaceutical preparation 'Fotosens', used in photodynamic therapy. The excitation source was an Nd:YAG laser emitting at the 1064 nm wavelength. The spectra of the two-photon-excited luminescence were obtained and the two-photon absorption cross sections were determined. (lasers in medicine)

Meshalkin, Yu P; Alfimov, E E; Makukha, V K [Novosibirsk State Technical University, Novosibirsk (Russian Federation); Vasil'ev, N E; Denisov, A N; Ogirenko, A P [Siberian Laser Medicine Centre, Novosibirsk (Russian Federation)

1999-12-31

101

Al-Cr-Nb (Aluminium - Chromium - Niobium)  

Microsoft Academic Search

This document is part of Subvolume A1 'Light Metal Systems. Part 1: Selected Systems from Ag-Al-Cu to Al-Cu-Er' of Volume 11 'Ternary Alloy Systems - Phase Diagrams, Crystallographic and Thermodynamic Data critically evaluated by MSIT®' of Landolt-Börnstein - Group IV Physical Chemistry. It provides the data for the ternary system Al-Cr-Nb (Aluminium - Chromium - Niobium).

2004-01-01

102

Structure of Pure Aluminium-Silicon Eutectics.  

National Technical Information Service (NTIS)

The natural form of the silicon in the pure aluminiumsilicon eutectic at slow growth rates is continuous 'rods'. The silicon phase is ahead of the aluminium phase during the growth process. A remarkably simple explanation is given in terms of constitution...

J. A. E. Bell W. C. Winegard

1964-01-01

103

Splat cooling of aluminium-manganese alloys  

Microsoft Academic Search

The gun technique of splat cooling is utilized to extend the solid solubility of manganese in aluminium by a factor of four above that at the eutectic temperature. The supersaturated solid solutions can be retained up to 250° C without any significant decomposition. Isochronal and isothermal studies of the variation of the lattice parameter of the 6.4 wt % manganese

S. P. Bhat; T. R. Ramachandran; A. K. Jena

1974-01-01

104

Modelling recrystallization after hot deformation of aluminium  

Microsoft Academic Search

A physically based model for predicting recrystallization microstructures and textures after hot deformation of aluminium is presented. The modelling approach taken differs from similar models developed for steels. The present model is based on recent experimental investigations directed towards identifying the nature of the nucleation sites for recrystallized grains of different crystallographic orientations. Particle stimulated nucleation, nucleation from cube bands

H. E. Vatne; T. Furu; R. Ørsund; E. Nes

1996-01-01

105

Aluminium in allergen-specific subcutaneous immunotherapy - A German perspective.  

PubMed

We are living in an "aluminium age" with increasing bioavailability of the metal for approximately 125 years, contributing significantly to the aluminium body burden of humans. Over the course of life, aluminium accumulates and is stored predominantly in the lungs, bones, liver, kidneys and brain. The toxicity of aluminium in humans is briefly summarised, highlighting links and possible causal relationships between a high aluminium body burden and a number of neurological disorders and disease states. Aluminium salts have been used as depot-adjuvants successfully in essential prophylactic vaccinations for almost 100 years, with a convincing positive benefit-risk assessment which remains unchanged. However, allergen-specific immunotherapy commonly consists of administering a long-course programme of subcutaneous injections using preparations of relevant allergens. Regulatory authorities currently set aluminium limits for vaccines per dose, rather than per treatment course. Unlike prophylactic vaccinations, numerous injections with higher proportions of aluminium-adjuvant per injection are applied in subcutaneous immunotherapy (SCIT) and will significantly contribute to a higher cumulative life dose of aluminium. While the human body may cope robustly with a daily aluminium overload from the environment, regulatory cumulative threshold values in immunotherapy need further addressing. Based on the current literature, predisposing an individual to an unusually high level of aluminium, such as through subcutaneous immunotherapy, has the potential to form focal accumulations in the body with the propensity to exert forms of toxicity. Particularly in relation to longer-term health effects, the safety of aluminium adjuvants in immunotherapy remains unchallenged by health authorities - evoking the need for more consideration, guidance, and transparency on what is known and not known about its safety in long-course therapy and what measures can be taken to prevent or minimise its risks. The possibility of providing an effective means of measuring aluminium accumulation in patients undergoing long-term SCIT treatment as well as reducing their aluminium body burden is discussed. PMID:24892252

Kramer, Matthias F; Heath, Matthew D

2014-07-16

106

Amazing Addition!!  

NSDL National Science Digital Library

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 ...

Staggs, Ms.

2008-04-01

107

The significance of water ionic strength on aluminium toxicity in brown trout (Salmo trutta L.).  

PubMed

The toxicity of aluminium to fish is related to interactions between aluminium and the gill surface. We investigated the possible effect of water ionic strength on this interaction. The mortality of brown trout (Salmo trutta L.) exposed to three different degrees of Al polymerisation was compared in water with increased ionic strength (mean 7.31 x 10(-4) M) after additions of the base cations Ca2+, Mg2+, Na+ or K+, and in water with no such addition (mean ionic strength 5.58 x 10(-4) M). Only a very slight ameliorating effect of increased ionic strength was observed, while the degree of Al polymerisation was of major importance in fish mortality. In addition, it was observed that smaller fish survived the Al exposures for a longer time than larger fish. We hypothesise that this is because larger fish are more susceptible to hypoxia than smaller fish. PMID:15519464

Alstad, Nina E W; Kjelsberg, Birgitte M; Vøllestad, L Asbjørn; Lydersen, Espen; Poléo, Antonio B S

2005-01-01

108

Amazing Addition!!  

NSDL National Science Digital Library

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 ...

Bolton, Ms.

2009-04-22

109

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

PubMed Central

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.

Pongjanyakul, T.; Rojtanatanya, S.

2012-01-01

110

Food additives  

MedlinePLUS

... appealing Direct additives may be man-made or natural. Natural additives include: Adding herbs or spices to foods ... appearance of foods. Many spices, as well as natural and man-made flavors, bring out the taste ...

111

Fatigue crack propagation in aluminium alloy foams  

Microsoft Academic Search

The mode I fatigue crack propagation (FCP) response of the closed-cell aluminium alloy foams Alulight and Alporas have been measured for a relative density in the range 0.1 to 0.4. The validity of linear elastic fracture mechanics (LEFM) to characterise the fatigue crack propagation (FCP) response is demonstrated, and K-increasing and K-decreasing tests are used to determine the full shape

O. B. Olurin; K. Y. G. McCullough; N. A. Fleck; M.F. Ashby

2001-01-01

112

The forces for projectile penetration of aluminium  

Microsoft Academic Search

A technique to measure the force-penetration behaviour of projectiles penetrating metal targets has been developed and used to examine the penetration characteristics of projectiles impacting soft 2S aluminium.The maximum force measured during complete penetration of a plate of given thickness was found to be essentially independent of projectile geometry, but the geometry influenced the total energy required for the same

A L Wingrove

1972-01-01

113

Defect production rates in electron irradiated aluminium  

Microsoft Academic Search

The cross section for atomic displacement has been determined at 7.5°K by means of electrical resistivity measurements in electron irradiated aluminium up to transferred energies of 1100 eV. These data and those from the literature have been evaluated with respect to the displacement function (DF). Below 200 eV the DF could be derived from the data with sufficient accuracy by

J. Wurm; F. Dworschak; H. Schuster; H. Wollenberger

1970-01-01

114

Warm Deep Drawing of Aluminium Sheet  

Microsoft Academic Search

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.

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

2003-01-01

115

Structure of liquid aluminium-silicon alloys  

Microsoft Academic Search

The Kumar-Samarin technique of centrifuging was adopted to study the structure of aluminium-silicon alloys in terms of the concept of the existence of clusters in liquid state. The investigation shows that in hypo-eutectic alloys the clusters are denser than the monatomic matrix whilst in hyper-eutectic alloys they are lighter. It is suggested that this difference in the distribution of silicon

Manjit Singh; Rajendra Kumar

1973-01-01

116

Titanium diboride particle-reinforced aluminium with high wear resistance  

Microsoft Academic Search

A TiB2 particle (61 vol%, 4 µm mean size) reinforced aluminium fabricated by liquid-aluminium infiltration was subjected to unlubricated rolling wear and was found from the weight loss to be 1.5 times more wear resistant than 17-4 ph stainless steel, twice as wear resistant as 1020 steel, 7.5 times more wear resistant than 2024 aluminium, and 12.8 times more wear

A. V. Smith; D. D. L. Chung

1996-01-01

117

X-ray photoelectron spectroscopy of aluminium-substituted tobermorite  

Microsoft Academic Search

We have synthesised 11-Å tobermorite hydrothermally, both pure and with increasing isomorphic substitution of aluminium for silicon. The samples were analysed by X-ray photoelectron spectroscopy (XPS). Aluminium was found, on the basis of its Al 2p binding energies, to be tetrahedrally coordinated. We observed no changes in Ca\\/(Si+Al) ratio upon aluminium substitution, implying that charge balancing does not occur via

Leon Black; Andreas Stumm; Krassimir Garbev; Peter Stemmermann; Keith R. Hallam; Geoffrey C. Allen

2005-01-01

118

Modifier role of cerium in lithium aluminium borate glasses  

NASA Astrophysics Data System (ADS)

Lithium aluminium borate glasses doped with CeO2 at the expense of Al2O3 have been prepared by melt quench technique. An intense fluorescence has been recorded when excited at 350 nm giving a large Stoke's shift. This emission has been attributed to 5d ? 4f transitions of Ce3+. An increase in fluorescence intensity, shifting of UV absorption edge towards longer wavelength and a decrease in band gap with addition of CeO2 concentration has been observed. Moreover densification and stabilization of glass network has been observed which is due to conversion of BO3 units to BO4 units since CeO2 at low concentrations act as a network modifier.

Kaur, Parvinder; Singh, Gurinder Pal; Kaur, Simranpreet; Singh, D. P.

2012-08-01

119

Mechanical Properties of Particulate Reinforced Aluminium Alloy Matrix Composite  

NASA Astrophysics Data System (ADS)

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.

Sayuti, M.; Sulaiman, S.; Baharudin, B. T. H. T.; Arifin, M. K. A.; Suraya, S.; Vijayaram, T. R.

2011-01-01

120

Effects of aluminium surface morphology and chemical modification on wettability  

NASA Astrophysics Data System (ADS)

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.

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

2014-03-01

121

Alteration of aluminium inhibition of synaptosomal (Na(+)/K(+))ATPase by colestipol administration.  

PubMed

The ability of aluminium to inhibit the (Na(+)/K(+))ATPase activity has been observed by several authors. During chronic dietary exposure to AlCl3, brain (Na(+)/K(+))ATPase activity drops, even if no alterations of catalytic subunit protein expression and of energy charge potential are observed. The aluminium effect on (Na(+)/K(+))ATPase activity seems to implicate the reduction of interacting protomers within the oligomeric ensemble of the membrane-bound (Na(+)/K(+))ATPase. The activity of (Na(+)/K(+))ATPase is altered by the microviscosity of lipid environment. We studied if aluminium inhibitory effect on (Na(+)/K(+))ATPase is modified by alterations in synaptosomal membrane cholesterol content. Adult male Wistar rats were submitted to chronic dietary AlCl3 exposure (0.03 g/day of AlCl3) and/or to colestipol, a hypolidaemic drug (0.31 g/day) during 4 months. The activity of (Na(+)/K(+))ATPase was studied in brain cortex synaptosomes with different cholesterol contents. Additionally, we incubate synaptosomes with methyl-?-cyclodextrin for both enrichment and depletion of membrane cholesterol content, with or without 300 ?M AlCl3. This enzyme activity was significantly reduced by micromolar AlCl3 added in vitro and when aluminium was orally administered to rats. The oral administration of colestipol reduced the cholesterol content and concomitantly inhibited the (Na(+)/K(+))ATPase. The aluminium inhibitory effect on synaptosomal (Na(+)/K(+))ATPase was reduced by cholesterol depletion both in vitro and in vivo. PMID:23829947

Silva, V S; Oliveira, L; Gonçalves, P P

2013-11-01

122

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

Microsoft Academic Search

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

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

2008-01-01

123

Risk of acute toxicity for fish during aluminium application to hardwater lakes  

Microsoft Academic Search

To assess the risk of aluminium (Al) toxicity during the restoration of the eutrophic lake Tiefwarensee by hypolimnetic addition of NaAl(OH)4-solution (aluminate) the generally limnological monitoring was accompanied by fractionation of Al in water and using Al accumulation on fish gills as bioindicator. The concentration of reactive Al species in the alkaline water (pH 8) peaked at 2mgL?1 in parts

Gerlinde Wauer; Hans-Christian Teien

2010-01-01

124

The formation and stability of ?-aluminium oxynitride spinel in the carbothermal reduction and reaction sintering processes  

Microsoft Academic Search

Several methods of manufacturing ?-aluminium oxynitride spinel (ALON) powder are discussed in this paper. In the carbothermal\\u000a reduction process, ALON is an intermediate compound, and powders with a high ALON content may be produced in flowing nitrogen\\u000a below 1650 C if process parameters are carefully controlled. In addition, ALON may be produced when Al2O3\\/C mixtures are\\u000a heated in a coke

LI YAWEI; LI NAN; YUAN RUNZHANG

1997-01-01

125

SIMS Investigations on the Distribution of Trace Elements in Modified Aluminium–Silicon–Magnesium Alloys  

Microsoft Academic Search

.  ?Strontium modified aluminium–silicon cast alloys are well known for their outstanding mechanical properties as they combine\\u000a excellent strength with good ductility that is due to a modification of brittle Si in the eutectic with traces of Sr (0.3–0.5?wt%).\\u000a Although the level of Sr addition is very low, formation of ternary AlSiSr phases with deleterious effects on the ductility\\u000a can take

Katharina Gammer; Erhard Ogris; Peter J. Uggowitzer; Herbert Hutter

2003-01-01

126

Development of joining process between aluminium alloy and stainless steel by using plastic flow in automotive parts  

Microsoft Academic Search

In recent years, a lot of process innovations are strongly required for cost and weight reductions in addition to upgrading driving performance and reducing greenhouse grasses in automotive industry. In case of manufacturing automotive parts, a number of materials are used to satisfy their high accuracy and cost reduction. Dissimilar metal joint such as combination of aluminium alloy and austenitic

Hideaki Shirai; Masahito Mochizuki; Masao Toyoda

2012-01-01

127

An ellipsometry study on the effect of aluminium chloride and ferric chloride formulations on mucin layers adsorbed at hydrophobic surfaces  

Microsoft Academic Search

Ellipsometry was used to investigate the effect of polyaluminium chloride (PAC) formulations of different degrees of hydrolysation on an adsorbed mucin film. The results were compared to the effect of aluminium chloride (AlCl3) and ferric chloride. A compaction of the mucin film took place upon addition of the formulations and this occurred to different extents and at different concentrations for

Jildiz Hamit-Eminovski; Krister Eskilsson; Thomas Arnebrant

2010-01-01

128

Prevalence of beryllium sensitization among aluminium smelter workers  

PubMed Central

Background Beryllium exposure occurs in aluminium smelters from natural contamination of bauxite, the principal source of aluminium. Aims To characterize beryllium exposure in aluminium smelters and determine the prevalence rate of beryllium sensitization (BeS) among aluminium smelter workers. Methods A population of 3185 workers from nine aluminium smelters owned by four different aluminium-producing companies were determined to have significant beryllium exposure. Of these, 1932 workers participated in medical surveillance programmes that included the serum beryllium lymphocyte proliferation test (BeLPT), confirmation of sensitization by at least two abnormal BeLPT test results and further evaluation for chronic beryllium disease in workers with BeS. Results Personal beryllium samples obtained from the nine aluminium smelters showed a range of <0.01–13.00 ?g/m3 time-weighted average with an arithmetic mean of 0.25 ?g/m3 and geometric mean of 0.06 ?g/m3. Nine workers were diagnosed with BeS (prevalence rate of 0.47%, 95% confidence interval = 0.21–0.88%). Conclusions BeS can occur in aluminium smelter workers through natural beryllium contamination of the bauxite and further concentration during the refining and smelting processes. Exposure levels to beryllium observed in aluminium smelters are similar to those seen in other industries that utilize beryllium. However, compared with beryllium-exposed workers in other industries, the rate of BeS among aluminium smelter workers appears lower. This lower observed rate may be related to a more soluble form of beryllium found in the aluminium smelting work environment as well as the consistent use of respiratory protection.

Slade, M. D.; Cantley, L. F.; Kirsche, S. R.; Wesdock, J. C.; Cullen, M. R.

2010-01-01

129

There is (still) too much aluminium in infant formulas  

PubMed Central

Background Infant formulas are sophisticated milk-based feeds for infants which are used as a substitute for breast milk. Historically they are known to be contaminated by aluminium and in the past this has raised health concerns for exposed infants. We have measured the aluminium content of a number of widely used infant formulas to determine if their contamination by aluminium and consequent issues of child health persists. Methods Samples of ready-made milks and powders used to make milks were prepared by microwave digestion of acid/peroxide mixtures and their aluminium content determined by THGA. Results The concentration of aluminium in ready-made milks varied from ca 176 to 700 ?g/L. The latter concentration was for a milk for preterm infants. The aluminium content of powders used to make milks varied from ca 2.4 to 4.3 ?g/g. The latter content was for a soya-based formula and equated to a ready-to-drink milk concentration of 629 ?g/L. Using the manufacturer's own guidelines of formula consumption the average daily ingestion of aluminium from infant formulas for a child of 6 months varied from ca 200 to 600 ?g of aluminium. Generally ingestion was higher from powdered as compared to ready-made formulas. Conclusions The aluminium content of a range of well known brands of infant formulas remains high and particularly so for a product designed for preterm infants and a soya-based product designed for infants with cow's milk intolerances and allergies. Recent research demonstrating the vulnerability of infants to early exposure to aluminium serves to highlight an urgent need to reduce the aluminium content of infant formulas to as low a level as is practically possible.

2010-01-01

130

Development of a cryopreservation procedure using aluminium cryo-plates.  

PubMed

A cryopreservation procedure using an aluminium cryo-plate was successfully developed using in vitro-grown Dalmatian chrysanthemum (Tanacetum cinerariifolium) shoot tips. Shoot cultures were cold-hardened at 5 degree C on MS medium containing 0.5 M sucrose over a period of 20 to 40 days. Shoot tips with basal plate (1.0-1.5 x 1.0 mm) were dissected from shoot cultures and precultured at 5 degree C for 2 days on MS medium containing 0.5 M sucrose. Precultured shoot tips were placed on aluminium cryo-plates (7 mm x 37 mm x 0.5 mm) with 10 wells (diameter 1.5 mm, depth 0.75 mm) and embedded in alginate gel. Osmoprotection was performed by immersing the cryo-plates for 30 or 60 min in 25 ml pipetting reservoirs filled with loading solution (2 M glycerol + 1.4 M sucrose). For dehydration, the loading solution was replaced with PVS 7M vitrification solution (30 percent glycerol, 19.5 percent ethylene glycol and 0.6 M sucrose in liquid MS basal medium), which was applied for 40 min. After rapid immersion in liquid nitrogen, shoot tips attached to the cryo-plates were rewarmed by immersion in cryotubes containing 2 ml 1 M sucrose solution. Using this procedure, regrowth of cryopreserved shoot tips of line 28v-75 reached 77 degree. This protocol was successfully applied to six additional lines, with high regrowth percentages ranging from 65 to 90 percent. By contrast, the modified vitrification protocol tested as a reference produced only moderate regrowth percentages. This new method displays many advantages and will facilitate large scale cryostorage in genebank. PMID:21766155

Yamamoto, Shin-ichi; Rafique, Tariq; Priyantha, Wickramage Saman; Fukui, Kuniaki; Matsumoto, Toshikazu; Niino, Takao

2011-01-01

131

Relationship between microstructure, hardness and electrical conductivity of 2219 aluminium  

Microsoft Academic Search

A TEM study of unstretched, heat-treated aluminium alloy 2219 was performed with the aim of correlating the microstructure with hardness (H) and eddy current conductivity (C) data. Recently Chihoski has developed a new method of evaluating heat treatments of aluminium alloys by constructing in an H-C field a “sail” formed by a network of curved coordinate lines of quenching and

M. Natan; R. A. Chihoski

1983-01-01

132

Laser micro welding of copper and aluminium using filler materials  

Microsoft Academic Search

The most evident trend in electronics production is towards miniaturization. Regarding the materials involved, another trend can be observed: intelligent combinations of different materials. One example is the combination of copper and aluminium. Copper is the material of choice for electronic packaging applications due to its superior electrical and thermal conductivity. On the other hand, aluminium offers technical and economical

Gerd Esser; Ihor Mys; Michael H. Schmidt

2004-01-01

133

Cold rolling and lubricated wear of 5083 aluminium alloy  

Microsoft Academic Search

The effect of cold deformation on the lubricated wear of 5083 aluminium alloy was investigated. SAE 10W was selected as liquid lubricant. The aluminium alloy was submitted to a cold rolling process, until the average thickness of the specimens was reduced by 7% and 15% respectively. From the experimental results obtained, the Stribeck curves for the as received and cold

C. N. Panagopoulos; E. P. Georgiou

2010-01-01

134

Corrosion of aluminium components studied with MIES, UPS and XPS  

NASA Astrophysics Data System (ADS)

We use X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS) and metastable impact electron spectroscopy (MIES) to investigate the corrosion of aluminium components. Clean aluminium films were prepared under ultrahigh vacuum (UHV) conditions and exposed to water and NaCl. We attempt to provide a model for the mechanism of this interaction and its effects on the durability of the components.

Frerichs, Martin; Voigts, Florian; Hollunder, Sven; Masendorf, Rainer; Esderts, Alfons; Maus-Friedrichs, Wolfgang

2005-09-01

135

Experimental investigation of the friction coefficient between aluminium and steel  

Microsoft Academic Search

The coefficient of friction for steel-aluminium contact surfaces has been determined. The test was conducted by using a testing machine active on the basis of the twist-compression test. A flat plate of aluminium was placed under pressure between two steel dies. One of the dies (the upper one) was capable of rotating while the other (the lower one) was stationary

M. JAVADI; M. TAJDARI

2006-01-01

136

Hydroforming of sheet metal pairs from aluminium alloys  

Microsoft Academic Search

New production technologies like the hydroforming of sheet metal pairs have to be qualified for both steel and aluminium alloy sheets. While good mechanical properties and the excellent recyclability make sheets from aluminium alloys a good choice of material for lightweight construction, the lower formability compared to steel sheets raises various challenges for part manufacturing. Forming problems in the hydroforming

S. Novotny; P. Hein

2001-01-01

137

Embodied energy analysis of aluminium-clad windows  

Microsoft Academic Search

This article provides an overview of energy loads associated with the application of powder coated aluminium profiles on the exterior wooden surface of double glazed windows. The entire powder coating process has been analysed to measure its energy and environmental contribution towards window cladding. Materials involved in aluminium clad windows have been analysed for their energy impacts. The energy embodied

M. Asif; A. Davidson; T. Muneer

2001-01-01

138

Aluminium salt slag characterization and utilization--a review.  

PubMed

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

Tsakiridis, P E

2012-05-30

139

Development of Automatic Welding System for TPS Aluminium Bending Chambers  

Microsoft Academic Search

Two novel automatic Gas Tungsten Arc Welding (GTAW) systems have been developed at National Synchrotron Radiation Research Center for welding Taiwan Photon Source (TPS) aluminium bending chambers. One automatic system is designed by using two welding torches to implement two parallel welds on each side of an aluminium chamber simultaneously. The other is to use an industrial 6-axis robot with

C L Chen; S N Hsu; C C Chang; C K Kuan; Y B Chen; C Y Yang; C K Chan; H P Hsueh; G. Y. Hsiung; J. R. Chen

140

Obtaining weld pool vision information during aluminium alloy TIG welding  

Microsoft Academic Search

An image sensing system for the TIG (tungsten inert-gas arc) welding process of aluminium alloy was established. The relationships between the image sensing system and the characteristic of welding current were discussed in detail. Front and back images of the weld pool were obtained with different welding parameters. In order to process the image, the characteristics of an aluminium alloy

J. J. Wang; T. Lin; S. B. Chen

2005-01-01

141

Dissolved aluminium in the Southern Ocean  

NASA Astrophysics Data System (ADS)

Dissolved aluminium (Al) occurs in a wide range of concentrations in the world oceans. The concentrations of Al in the Southern Ocean are among the lowest ever observed. An all-titanium CTD sampling system makes it possible to study complete deep ocean sections of Al and other trace elements with the same high vertical resolution of 24 depths as normal for traditional CTD/Rosette sampling. Overall, 470 new data points of Al are reported for 22 full depth stations and 24 surface sampling positions along one transect. This transect consisted of 18 stations on the zero meridian proper from 51°57' S until 69°24'S, and 4 stations somewhat to the northeast towards Cape Town from 42°20'S, 09°E to 50°17'S, 01°27'E. The actual concentrations of Al in the Southern Ocean were lower than previously reported. The concentration of Al in the upper 25 m was relatively elevated with an average concentration of 0.71 nM ( n=22; S.D.=0.43 nM), most likely due to atmospheric input by a suggested combination of direct atmospheric (wet and dry) input and indirect atmospheric input via melting sea ice. Below the surface waters there was a distinct Al minimum with an average concentration of 0.33 nM ( n=22; S.D.=0.13 nM) at an average depth of 120 m. In the deep southernmost Weddell Basin the concentration of Al increased with depth to ˜0.8 nM at 4000 m, and a higher concentration of ˜1.5 nM in the ˜4500-5200 m deep Weddell Sea Bottom Water. Over the Bouvet triple junction region, where three deep ocean ridges meet, the concentration of Al increased to ˜1.4 nM at about 2000 m depth over the ridge crest. In the deep basin north of the Bouvet region the concentration of Al increased to higher deep values of 4-6 nM due to influence of North Atlantic Deep Water. In general the intermediate and deep distribution of Al results from the mixing of water masses with different origins, the formation of deep water and additional input from sedimentary sources at sea floor elevations. No significant correlation between Al and silicate (Si) was observed. This is in contrast to some other ocean regions. In the Southern Ocean the supply of Al is extremely low and any signal from Al uptake and dissolution with biogenic silica is undetectable against the high dissolved Si and low dissolved Al concentrations. Here the Al-Si relation in the deep ocean is uncoupled. This is due to the scavenging and subsequent loss of the water column of Al, whereas the concentration of Si increases in the deep ocean due to its input from deep dissolution of biogenic diatom frustules settling from the surface layer.

Middag, R.; van Slooten, C.; de Baar, H. J. W.; Laan, P.

2011-12-01

142

Multilayer roll bonded aluminium foil: processing, microstructure and flow stress  

SciTech Connect

Bulk aluminium has been produced by warm-rolling followed by cold-rolling of commercial purity (99% purity) aluminium foil. The bonding appeared perfect from observation with the naked eye, light and transmission electron microscopy. By comparison with bulk aluminium of similar purity (AA1200) rolled to a similar strain (90%RA), the roll-bonded metal showed a much higher density of high-angle grain boundaries, similar strength and improved thermal stability. This study has implications for a number of applications in relation to the processing of aluminium. Roll bonding is of interest as a method for grain size refinement; oxide-containing materials have increased strength, enhanced work-hardening behaviour, and exhibit alterations in recrystallisation behaviour. The behaviour of the hard oxide film is of interest in aluminium processing, and has been investigated by characterising the size and distribution of oxide particles in the roll-bonded samples.

Barlow, C.Y.; Nielsen, P.; Hansen, N

2004-08-02

143

Albumin adsorption on to aluminium oxide and polyurethane surfaces.  

PubMed

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

Sharma, C P; Sunny, M C

1990-05-01

144

Atmospheric plasma torch treatment of aluminium: Improving wettability with silanes  

NASA Astrophysics Data System (ADS)

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.

Díaz-Benito, B.; Velasco, F.

2013-12-01

145

The effective thermal conductivity of insulation materials reinforced with aluminium foil at low temperatures  

NASA Astrophysics Data System (ADS)

The effective thermal conductivity (ETC) of multilayer thermal insulation materials was experimentally investigated as a function of temperature (0-25 °C). The materials consisted of binary/ternary glass wools or ternary expanded polystyrene foams reinforced with aluminium foil. The experimental measurements were performed using a guarded hot plate with temperature differences of 5, 10 and 15 °C. The results indicated that significant correlations exist between ETC and the characteristics of the materials with decreasing temperature. The ETC decreases with reinforcement with aluminium foil at the same temperature or with temperature differences of 5 and 15 °C. In addition, it was clearly observed that the ETC decreases sharply with decreased temperature. Consequently, reflective materials may reduce the ETC at low temperatures.

Yüksel, N.; Avc?, A.; K?l?ç, M.

2012-09-01

146

Composite Ni-Co-fly ash coatings on 5083 aluminium alloy  

NASA Astrophysics Data System (ADS)

Ni-Co-fly ash coatings were deposited on zincate treated 5083 wrought aluminium alloy substrates with the aid of the electrodeposition technique. Structural and chemical characterization of the produced composite coatings was performed with the aid of X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron dispersive X-ray analysis (EDS) techniques. The Ni-Co-fly ash coatings were found to consist of a crystalline Ni-Co solid solution with dispersed fly ash particles. In addition, chemical analysis of the Ni-Co matrix showed that it consisted of 80 wt.% Ni and 20 wt.% Co. The co-deposition of fly ash particles leads to a significant increase of the microhardness of the coating. The corrosion behaviour of the Ni-Co-fly ash/zincate coated aluminium alloy, in a 0.3 M NaCl solution (pH = 3.5), was studied by means of potentiodynamic corrosion experiments.

Panagopoulos, C. N.; Georgiou, E. P.; Tsopani, A.; Piperi, L.

2011-03-01

147

Evaluation of the mechanical properties of microarc oxidation coatings and 2024 aluminium alloy substrate  

NASA Astrophysics Data System (ADS)

A determination of the phase constituents of ceramic coatings produced on Al-Cu-Mg alloy by microarc discharge in alkaline solution was performed using x-ray diffraction. The profiles of the hardness, H, and elastic modulus, E, across the ceramic coating were determined by means of nanoindentation. In addition, a study of the influence of microarc oxidation coatings on the tensile properties of the aluminium alloy was also carried out. The results show that the H-and E-profiles are similar, and both of them exhibit a maximum value at the same depth of coating. The distribution of the ?-Al2O3 phase content determines the H- and E-profiles of the coatings. The tensile properties of 2024 aluminium alloy show less change after the alloy has undergone microarc discharge surface treatment.

Xue, Wenbin; Wang, Chao; Deng, Zhiwei; Chen, Ruyi; Li, Yongliang; Zhang, Tonghe

2002-11-01

148

Modelling of Laser Spall Experiments on Aluminium  

NASA Astrophysics Data System (ADS)

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.

Robinson, C. M.

2001-06-01

149

Special features of aluminium-coated steels in active gas media  

Microsoft Academic Search

It is established that weld metal saturation by aluminium occurs at welding steels coated by aluminium, and this decreases mechanical properties of the welded joints substantially. Application of the gaseous medium with high oxidizing ability at welding allows for refining weld metal from aluminium and for improving strength and plastic properties of the aluminium-coated steel welded joints.

T. V. Chermashentseva; A. I. Kovtunov

2011-01-01

150

Static and dynamic behavior of combined composite aluminium tube for automotive applications  

Microsoft Academic Search

The objective of this work is to study the crushing behavior and the influence of surface treatments on an aluminium alloy before bonding with a carbon\\/epoxy composite. Two geometries of aluminium circular tubes are used, allowing a stable crushing mode. Chemical etching and degreasing were applied to the aluminium tube to improve adhesion between composite and aluminium. To compare the

J Bouchet; E Jacquelin; P Hamelin

2000-01-01

151

Potlining Additives  

SciTech Connect

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.

Rudolf Keller

2004-08-10

152

Evaluation of certain food additives and contaminants.  

PubMed

This report represents the conclusions of a Joint FAO/WHO Expert Committee convened to evaluate the safety of various food additives, with a view to recommending acceptable daily intakes (ADIs) and to preparing specifications for identity and purity. The Committee also evaluated the risk posed by two food contaminants, with the aim of deriving tolerable intakes where appropriate and advising on risk management options for the purpose of public health protection. 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 and contaminants. A summary follows of the Committee's evaluations of technical, toxicological and dietary exposure data for certain food additives (aluminium-containing food additives, Benzoe Tonkinensis, glycerol ester of gum rosin, glycerol ester of tall oil rosin, glycerol ester of wood rosin, octenyl succinic acid modified gum arabic, polydimethyl siloxane, Ponceau 4R, pullulan, pullulanase from Bacillus deromificans expressed in Bacillus licheniformis, Quinoline Yellow and Sunset Yellow FCF) and two food contaminants (cyanogenic glycosides and fumonisins). Specifications for the following food additives were revised: aluminium lakes of colouring matters; beta-apo-8'-carotenal; beta-apo-8'-carotenoic acid ethyl ester; beta-carotene, synthetic; hydroxypropyl methyl cellulose; magnesium silicate, synthetic; modified starches; nitrous oxide; sodium carboxymethyl cellulose; and sucrose monoesters of lauric, palmitic or stearic acid. Annexed to the report are tables summarizing the Committee's recommendations for dietary exposures to and toxicological evaluations of the food additives and contaminants considered. PMID:22519244

2011-01-01

153

Cholinergic System Under Aluminium Toxicity in Rat Brain  

PubMed Central

The present investigation envisages the toxic effects of aluminium on the cholinergic system of male albino rat brain. Aluminium toxicity (LD50/24 h) evaluated as per Probit method was found to be 700 mg/kg body weight. One-fifth of lethal dose was taken as the sublethal dose. For acute dose studies, rats were given a single lethal dose of aluminium acetate orally for one day only and for chronic dose studies, the rats were administered with sublethal dose of aluminium acetate once in a day for 25 days continuously. The two constituents of the cholinergic system viz. acetylcholine and acetylcholinesterase were determined in selected regions of rat brain such as cerebral cortex, hippocampus, hypothalamus, cerebellum, and pons-medulla at selected time intervals/days under acute and chronic treatment with aluminium. The results revealed that while acetylcholinesterase activity was inhibited, acetylcholine level was elevated differentially in all the above mentioned areas of brain under aluminium toxicity, exhibiting area-specific response. All these changes in the cholinergic system were subsequently manifested in the behavior of rat exhibiting the symptoms such as adipsia, aphagia, hypokinesia, fatigue, seizures, etc. Restoration of the cholinergic system and overt behavior of rat to the near normal levels under chronic treatment indicated the onset of either detoxification mechanisms or development of tolerance to aluminium toxicity in the animal which was not probably so efficient under acute treatment.

Yellamma, K.; Saraswathamma, S.; Kumari, B. Nirmala

2010-01-01

154

Unexpected loss of contact allergy to aluminium induced by vaccine  

PubMed Central

Background In studies in Gothenburg, Sweden, in the 1990s of an aluminium hydroxide-adsorbed pertussis toxoid vaccine, 745 of ?76 000 vaccinated children developed long-lasting itchy subcutaneous nodules at the vaccination site. Of 495 children with itchy nodules patch tested for aluminium allergy, 376 (76%) were positive. Objectives To study the prognosis of the vaccine-induced aluminium allergy. Patients and methods Two hundred and forty-one children with demonstrated aluminium allergy in the previous study were patch tested again 5–9 years after the initial test, with the same procedure as used previously. Results Contact allergy to aluminium was no longer demonstrable in 186 of the retested 241 children (77%). A negative test result was more common in children who no longer had itching at the vaccination site; it was also related to the age of the child, the time after the first aluminium-adsorbed vaccine dose, and the strength of the reaction in the first test. Conclusions Patch test reactivity to aluminium seems to disappear or weaken with time.

Gente Lidholm, Anette; Bergfors, Elisabet; Inerot, Annica; Blomgren, Ulla; Gillstedt, Martin; Trollfors, Birger

2013-01-01

155

Fraction Addition  

NSDL National Science Digital Library

The following sites will provide some review and practice adding fractions. These links will help with finding common denominators. Equivalent Fractions Fraction Addition-Common Denominators Do some practice with visuals. Add Fractions with Like Denominators Add Fractions with Unlike Denominators See how fast you can get through these problems! Race the Clock-Add with Like Denominators Race the Clock-Add with Unlike Denominators Race the Clock-Add with Mixed Numbers Do you need a \\"How to...\\" refresher? Look here! How Do You Do That? Add with Like Demoninators How Do You Do That? Add with Unlike Demoninators How Do You Do That? Add with Mixed Numbers ...

Romney, Mrs.

2005-06-18

156

The behaviour of iron and aluminium during the diffusion welding of carbon steel to aluminium  

Microsoft Academic Search

The diffusion welding of carbon steel to aluminium may be achieved when the temperature and compression of the weld metal\\u000a allows diffusion at the interface between both components; the degree of interdiffusion largely determines the quality of\\u000a the welded joint. Such diffusion processes can take place under vacuum. However, in this paper, we report that high quality\\u000a welds can be

M. Kamal Karfoul; Gordon J. Tatlock; Robert T. Murray

2007-01-01

157

Elaboration et caractérisation de gels hybrides à base d'aluminium  

NASA Astrophysics Data System (ADS)

De nouveaux gels hybrides "organique—inorganique" à base d'aluminium sont élaborés par voie sol—gel. Le précurseur moléculaire utilisé est le butylate secondaire d'aluminium Al(OBu S) 3 dissous dans CCl 4, modifié par le propane-1,2-diol, le butane-1, x-diol ( x = 2, 3), et le pentane-1,2-diol. Nous avons étudié l'influence des principaux facteurs (nature du solvant, nature et quantité du diol) sur l'obtention des gels monolithiques et transparents. Toutes les préparations sont réalisées sans ajout d'eau. L'étude par RMN MAS 27Al, RMN CP MAS 13C, et par spectroscopie IR montre qu'une réaction d'échange a lieu entre les groupements OBus de l'alcoxyde d'aluminium et les diols utilisés. Les gels obtenussont monolithiques et transparents, les atomes d'aluminium y sont liés entre eux par des ponts organiques selon la formule —Al—O—R —O—Al— où R est une chaîne hydrocarbonée provenant du diol. This paper presents an original method for elaboration of gels with mixed organic—inorganic networks of the general formula —Al—O—R—O—Al—, with R being a hydrocarbon chain. Starting materials used are aluminum tri-sec-butoxide Al(O-sec-C 4H 9) 3, propane-1,2-diol, butane-1,2-diol, butane-1,3-diol, and pentane-1,2-diol. The reactions were carried out with either CCl 4 or cyclohexane as solvent. The exchange reaction between the diols and Al(O-sec-C 4H 9) 3 occurs with the elimination of sec-butanol molecules. Gels are obtained without the addition of water. The monolithic and transparent gels obtained are characterized by IR and as well as 13C and 27Al RMN techniques.

Touati, F.; Gharbi, N.; Zarrouk, H.

1995-11-01

158

Aluminium adjuvants--in retrospect and prospect.  

PubMed

Aluminium compounds have been used as adjuvants in practical vaccination for more than 60 years to induce an early, an efficient and a long lasting protective immunity and are at present the most widely used adjuvants in both veterinary and human vaccines. Although the last two decades of systematic research into the nature of these adjuvants has contributed significantly to understanding their nature and their limitations as Th2 stimulators the more detailed mode of action of these adjuvants is still not completely understood. We have a comprehensive record of their behaviour and performance in practical vaccination, but an empirical approach to optimising their use in new vaccine formulations is still to some extent a necessity. The aim of the present review is to put the recent findings into a broader perspective to facilitate the application of these adjuvants in general and experimental vaccinology. PMID:15315845

Lindblad, Erik B

2004-09-01

159

DNA Strand Patterns on Aluminium Thin Films  

PubMed Central

A new patterning method using Deoxyribose Nucleic Acid (DNA) strands capable of producing nanogaps of less than 100 nm is proposed and investigated in this work. DNA strands from Bosenbergia rotunda were used as the fundamental element in patterning DNA on thin films of aluminium (Al) metal without the need for any lithographic techniques. The DNA strands were applied in buffer solutions onto thin films of Al on silicon (Si) and the chemical interactions between the DNA strands and Al creates nanometer scale arbitrary patterning by direct transfer of the DNA strands onto the substrate. This simple and cost-effective method can be utilized in the fabrication of various components in electronic chips for microelectronics and Nano Electronic Mechanical System (NEMS) applications in general.

Khatir, Nadia Mahmoudi; Banihashemian, Seyedeh Maryam; Periasamy, Vengadesh; Majid, Wan Haliza Abd; Rahman, Saadah Abdul; Shahhosseini, Fatemeh

2011-01-01

160

Grain Size Control during Processing of Aluminium at Elevated Temperatures.  

National Technical Information Service (NTIS)

During hot forming of aluminium alloys, grain size control is of vital importance for the quality of the final product. A coarse grained material may result in orange peeling when bending and reduced strength and ductility, important mechanical properties...

R. Oersund O. Lohne

1991-01-01

161

Moving Up To Aluminium: Light, Strong and Profitable  

NSDL National Science Digital Library

In this brochure the European Aluminium Association (EAA) outlines the advantages of aluminum use in road transport. These advantages include environmental, revenue, energy, material composition, recycling, sustainability, and safety.

European Aluminium Association (EAA)

162

Deposition of aluminium nanoparticles using dense plasma focus device  

NASA Astrophysics Data System (ADS)

Plasma route to nanofabrication has drawn much attention recently. The dense plasma focus (DPF) device is used for depositing aluminium nanoparticles on n-type Si (111) wafer. The plasma chamber is filled with argon gas and evacuated at a pressure of 80 Pa. The substrate is placed at distances 4.0 cm, 5.0 cm and 6.0 cm from the top of the central anode. The aluminium is deposited on Si wafer at room temperature with two focused DPF shots. The deposits on the substrate are examined for their morphological properties using atomic force microscopy (AFM). The AFM images have shown the formation of aluminium nanoparticles. From the AFM images, it is found that the size of aluminium nanoparticles increases with increase in distance between the top of anode and the substrate for same number of DPF shots.

Bilasini Devi, Naorem; Roy, Savita; Srivastava, M. P.

2010-02-01

163

Joining of aluminium and copper materials with friction welding  

Microsoft Academic Search

Industrial use of non-ferrous materials is significant in the electrical and the chemical engineering applications. Copper–aluminium\\u000a joints are inevitable for certain applications due to unique performances such as higher electric conductivity, heat conductivity,\\u000a corrosion resistance and mechanical properties. Friction welding is the most common method used due to material and energy\\u000a saving. In the present study, copper and aluminium materials

Mumin Sahin

2010-01-01

164

Residual stresses in aluminium alloy friction stir welds  

Microsoft Academic Search

Residual stresses are detrimental to the fatigue, fracture and corrosion resistance of welds. The literature on residual stress\\u000a measurements in aluminium alloy friction stir welds is reviewed. The results of a large number of longitudinal residual stress\\u000a measurements performed by the slitting method on friction stir welds in 2024-T3, 6082-T6 and 5754-H111 aluminium alloys are\\u000a compared and their origin discussed.

Kevin Deplus; Aude Simar; Wim Van Haver; Bruno de Meester

165

Dietary exposure to aluminium of the Hong Kong population  

Microsoft Academic Search

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), some bakery products such as muffin, pancake\\/waffle, coconut tart and cake (mean: 250, 160, 120 and 91 mg kg, respectively), and jellyfish (ready-to-eat form)

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

2010-01-01

166

Abrasive wear of aluminium composites—a review  

Microsoft Academic Search

Aluminium-silicon alloys and aluminium-based metal-matrix composites (MMCs) containing hard particles offer superior operating performance and resistance to wear. In industrial processes where abrasive slurries are transported by rotating paddles or impellers, clements fabricated from MMC materials provide higher abrasive resistance and therefore a longer service life compared to those made from iron or nickel-based alloys. Composites characterized by a hardness

R. L. Deuis; C. Subramanian; J. M. Yellup

1996-01-01

167

Theoretical modelling of porous oxide growth on aluminium  

Microsoft Academic Search

A theoretical model for porous structure formation during electrochemical anodization of aluminium is developed taking into account anodic oxide growth at the oxide\\/electrolyte and oxide\\/aluminium interfaces, electrochemical and field-enhanced oxide dissolution, and a three-dimensional configuration of electric field and current in the scalloped barrier oxide layer at pore bottoms. A system of equations ensuring a general description of the porous

V. P. Parkhutik; V. I. Shershulsky

1992-01-01

168

Viscous pressure bulging of aluminium alloy sheet at warm temperatures  

Microsoft Academic Search

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

Jianguang Liu; Qiucai Peng; Yan Liu; Zhongjin Wang

2007-01-01

169

Characterization of rapidly solidified aluminium-silicon alloy  

Microsoft Academic Search

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

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

1987-01-01

170

Thermodynamics of liquid aluminium–copper–germanium alloys  

Microsoft Academic Search

Partial for aluminium and integral enthalpies of mixing of liquid Al–Cu–Ge alloys have been measured by high-temperature isoperibolic calorimetry at T=(1380±5) K. Thermodynamic activities, partial for aluminium and integral Gibbs free energies of mixing have been determined by the electromotive force method (emf) over the range 1050?T\\/K?1250. Integral excess entropies of mixing have been calculated from calorimetric enthalpies and emf

Dmitry S. Kanibolotsky; Nataliya V. Kotova; Olena A. Bieloborodova; Vladyslav V. Lisnyak

2003-01-01

171

Volatilisation and oxidation of aluminium scraps fed into incineration furnaces.  

PubMed

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

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

2012-12-01

172

Aluminium production as a source of atmospheric carbonyl sulfide (COS).  

PubMed

Carbonyl sulfide is found as a major sulfur compound in anodic gases of commercial aluminium electrolysis. Recent spectroscopic measurements on industrial aluminium smelters found typical CO/COS ratios between 80 and 200. This results in specific COS emissions of between 1 and 7 kg/t(Al) if all COS is released into the atmosphere. In 1993 aluminium production would have been responsible for between 0.02 and 0.14 Tg of COS emissions. Currently, aluminium production does not seem to influence the total atmospheric COS budget to an extent beyond its natural variability. If recent growth rates of global aluminium production are sustained, however, COS emissions would quadruple until 2030. Together with increasing aircraft emissions into the stratosphere, an increase of the sulfate background aerosol is to be expected that could significantly enhance ozone depletion. The use of inert anodes is recommended to reduce aluminium production emissions of COS and CF4, C2F6, CO2, and CO at the same time. PMID:24234611

Harnisch, J; Borchers, R; Fabian, P; Kourtidis, K

1995-11-01

173

Synthesis of nanowires and nanoparticles of cubic aluminium nitride  

NASA Astrophysics Data System (ADS)

Nanostructures of cubic aluminium nitride were synthesized by DC arc-plasma-induced melting of aluminium in a nitrogen-argon ambient. The material flux ejected from the molten aluminium surface was found to react with nitrogen under highly non-equilibrium conditions and subsequently condense on a water-cooled surface to yield a mixture of nanowires and nanoparticles of crystalline cubic aluminium nitride. Both x-ray diffraction and electron diffraction measurements revealed that the as-synthesized nitrides adopted the cubic phase. Fourier transform infrared spectroscopy was used to understand the bonding configuration. Microstructural features of the synthesized material were best studied by transmission electron microscopy. From these analyses cubic aluminium nitride was found to be the dominating phase for both nanowires and nanoparticles synthesized at low currents. The typical particle size distribution was found to range over 15-80 nm, whereas the wires varied from 30 to 100 nm in diameter and 500 to 700 nm in length, depending upon the process parameters such as arc current and the nitrogen pressure. The reaction products inside the plasma zone were also obtained theoretically by minimization of free energy and the favourable zone temperature necessary for the formation of aluminium nitride was found to be {\\sim } 6000 K. Results are discussed in view of the highly non-equilibrium conditions that prevail during the arc-plasma synthesis.

Balasubramanian, C.; Godbole, V. P.; Rohatgi, V. K.; Das, A. K.; Bhoraskar, S. V.

2004-03-01

174

Characterization and structure of precipitates in 6xxx Aluminium Alloys  

NASA Astrophysics Data System (ADS)

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.

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

2012-07-01

175

Optimization of phosphate removal in anodizing aluminium wastewater.  

PubMed

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

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

2006-01-01

176

Aluminium phosphide poisoning and oxidative stress: serum biomarker assessment.  

PubMed

According to previous animal studies, aluminium phosphides (AlPs) may induce oxidative stress leading to generation of free radicals and alteration in antioxidant defense system. This study was conducted to evaluate the existence and degree of oxidative stress in patients with acute AlP ingestion. A total of 44 acute AlP ingested patients as well as 44 age- and sex-matched controls were included. All patients had acute poisoning symptoms with AlP at the time of presentation and had blood samples analyzed for lipid peroxidation, total antioxidant capacity and total thiol. Our findings showed that there is a significant increase in lipid peroxidation in AlP ingested group along with a reduction in total antioxidant capacity and total thiols groups. These clinical data confirm previous experimental models that showed AlP exposure might significantly augment lipoperoxidative damage with simultaneous alterations in the antioxidant defense system. Hence, our findings might justify use of antioxidants in treatment of acute AlP poisoning which needs to be clarified by additional clinical trials. PMID:22407514

Kariman, Hamid; Heydari, Kamran; Fakhri, Mohammad; Shahrami, Ali; Dolatabadi, Ali Arhami; Mohammadi, Hossein Ali; Gharibi, Morteza

2012-09-01

177

Influence of rolling direction on strength and ductility of aluminium and aluminium alloys produced by accumulative roll bonding  

Microsoft Academic Search

Sheets from commercial purity aluminium AA1050 and aluminium alloy AA6016 were processed by accumulative roll bonding to obtain\\u000a an ultrafine-grained microstructure. The accumulative roll bonded samples showed a significant increase in specific strength\\u000a paired with high ductility. Despite a strongly elongated grain structure, tensile testing of samples oriented 45° to the rolling\\u000a direction revealed considerable improvement in elongation to failure

Irena Topic; Heinz Werner Höppel; Mathias Göken

2008-01-01

178

Chromosomal location of PCR fragments as a source of DNA markers linked to aluminium tolerance genes in rye  

Microsoft Academic Search

To identify and locate rye DNA sequences homologous to three wheat c-DNAs (wali1, wali2 and wali5) whose expression is induced by aluminium (Al) stress, we designed three pairs of specific primers. They were used in the\\u000a amplification of genomic DNA from wheat-rye disomic addition lines. The wali2 pair of primers amplified a 878-bp rye DNA fragment (rali2) located on chromosomes

F. J. Gallego; E. López-Solanilla; A. M. Figueiras; C. Benito

1998-01-01

179

The Toxic Effect of Aluminium on Barley Plants in Relation to Ionic Composition of the Nutrient Solution  

Microsoft Academic Search

Barley plants were grown in nutrient solutions in two greenhouse pot experiments after addition of 0 (0.5), 2, 6 and 12 mg aluminium pr. liter as Al2(SO4)3·18H2O. The Altreatments were combined with three levels of Ca+Mg-salt applications. Low pH value is a prerequisite for keeping Al in solution, and attempts were therefore made to produce low pH nutrient solutions without

Gotfred Uhlen

1985-01-01

180

Impedance spectroscopic study of aluminium and Al-alloys in acid solution: inhibitory action of nitrogen containing compounds  

Microsoft Academic Search

The adsorption behaviour of triethanolamine (TEA) on aluminium, AlMgSi and AlZnMg alloys covered with naturally formed oxide films was investigated in 0.5 M NaCl solution, pH 1.3, by means of potentiodynamic and electrochemical impedance spectroscopy techniques. The results of polarization measurements show that in all cases the addition of TEA induces a decrease in the cathodic currents without affecting the

M. Metikoš-Hukovi?; R. Babi?; Z. Gruba?; S. Brin?

1994-01-01

181

Aluminium foam sandwich structures for space applications  

NASA Astrophysics Data System (ADS)

Within a French/German research project the suitability of a new class of materials, so-called aluminium foam sandwiches (AFS), was tested for space applications. While classical sandwich materials require particular, cost and time intensive processing techniques, AFS are suitable for mass production technologies as they are known from car industry and the like. Thus, it is expected that such materials could essentially contribute to cost reduction in space. In order to test the principal applicability and to gain some first experience in how the manufacture of AFS space components could work, a cone 3936 as used in Ariane 5 was chosen as demonstrator. In the forefront, the material had been intensively tested considering mechanical and thermal properties. By means of FEM the results of these experiments were used to simulate the behaviour under load and to optimise the design accordingly. Using AFS suitable production methods, the cone was built and tested simulating the loads during launch. The test results were compared to the predictions made by FEM and showed good agreement.

Schwingel, Dirk; Seeliger, Hans-Wolfgang; Vecchionacci, Claude; Alwes, Detlef; Dittrich, Jürgen

2007-06-01

182

Fuzzy Multicriteria Ranking of Aluminium Coating Methods  

NASA Astrophysics Data System (ADS)

This work deals with multicriteria ranking of aluminium coating methods. The alternatives used are: sulfuric acid anodization, A1; oxalic acid anodization, A2; chromic acid anodization, A3; phosphoric acid anodization, A4; integral color anodizing, A5; chemical conversion coating, A6; electrostatic powder deposition, A7. The criteria used are: cost of production, f1; environmental friendliness of production process, f2; appearance (texture), f3; reflectivity, f4; response to coloring, f5; corrosion resistance, f6; abrasion resistance, f7; fatigue resistance, f8. Five experts coming from relevant industrial units set grades to the criteria vector and the preference matrix according to a properly modified Delphi method. Sensitivity analysis of the ranked first alternative A1 against the `second best', which was A3 at low and A7 at high resolution levels proved that the solution is robust. The dependence of anodized products quality on upstream processes is presented and the impact of energy price increase on industrial cost is discussed.

Batzias, A. F.

2007-12-01

183

Determination of aluminium with 8-hydroxyquinoline-5-sulfonic acid in presence of a cationic surfactant by first and second derivative synchronous fluorimetry  

SciTech Connect

An analytical method has been developed for the fluorimetric determination of nanogram amounts of aluminium in solution. The method is based on the reaction of aluminium with 8-hydroxyquinoline-5-sulfonic acid presence of hexadeciltrimethylammonium bromide as a surfactant agent. Synchronous scanned first and second derivative fluorimetry has been employed to increase the sensitivity of the method. The influence of reaction variables as well as instrumental parameters is discussed. The interference of various foreign ions has also been examined and in some cases eliminated or reduced by addition of 1,10-phenanthroline.

Salinas, F.; de la Pena, A.; Duran, M.S.

1988-08-01

184

Energy dispersive spectroscopy analysis of aluminium segregation in silicon carbide grain boundaries.  

PubMed

The aluminium distribution in polycrystalline SiC hot-pressed with aluminium, boron and carbon additives was studied using X-ray energy-dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). The Al excess in homophase SiC grain boundary films was determined, taking into account dissolved Al in the SiC lattice. In the spot-EDS analysis, an electron beam probe with a calibrated diameter was formed, and the total beam-specimen interaction volume was defined, taking the beam spreading through crystalline TEM foil into consideration. EDS spectra were collected from regions containing intergranular films and adjacent matrix grains, respectively. A theoretical treatment was presented and experimental errors were estimated, with a further discussion about the effects of foil thickness. Experimental examples are given, followed by statistical EDS analyses for grain boundary films in SiC samples hot-pressed with increased amounts of Al additions. The results demonstrated a substantial Al segregation in the nanometer-wide intergranular films in all samples. Al additions higher than 3 wt% saturated the Al concentrations in SiC grains and in grain boundary films. The effect of foil thickness, and the parameters for determining the optimum incident beam diameter in the EDS analysis are discussed. PMID:12135460

Zhang, X F; Yang, Q; De Jonghe, L C; Zhang, Z

2002-07-01

185

Methods for reducing weld porosity in argon-shielded arc welding of aluminium alloys  

Microsoft Academic Search

Cause analysis of porosity in aluminium argon-arc welded joints is carried out, particularly that of aluminium–lithium alloy 1424. Feasible production methods of reducing the quantity of voids in the joints are considered.

M. M. Shtrikman; A. V. Pinskii; A. A. Filatov; V. V. Koshkin; E. A. Mezentseva; N. V. Guk

2011-01-01

186

Irreversible and reversible adhesion between virus particles and hydrolyzing-precipitating aluminium: a function of coagulation.  

PubMed

The infectivity of viruses (Qbeta, MS2, T4, and P1) after dosing virus-contaminated water with 4 types of aluminium coagulant was investigated. The concentrations of infectious viruses were determined after dissolving aluminium hydroxide flocs in alkaline solution. The concentration of infectious viruses did not recover to the initial value after a short floc-dissolution time (5 s). Although the infectious virus concentration increased as the floc-dissolution time was extended to 5 h, it did not recover fully. Irreversible adhesion between virus particles and aluminium coagulant is responsible for the insufficient recovery. We interpret this phenomenon as a virucidal activity of the aluminium coagulant. All tested aluminium coagulants (PACl, alum, and reagent grade aluminium chloride and aluminium sulfate) inactivated all types of viruses tested. PACl had the highest virucidal activity. The virucidal activity of aluminium coagulants was lower in river water, presumably owing to the presence of natural organic matter. PMID:15686022

Matsushita, T; Matsui, Y; Inoue, T

2004-01-01

187

Corrosion of aluminium metal in OPC- and CAC-based cement matrices  

SciTech Connect

Corrosion of aluminium metal in ordinary Portland cement (OPC) based pastes produces hydrogen gas and expansive reaction products causing problems for the encapsulation of aluminium containing nuclear wastes. Although corrosion of aluminium in cements has been long known, the extent of aluminium corrosion in the cement matrices and effects of such reaction on the cement phases are not well established. The present study investigates the corrosion reaction of aluminium in OPC, OPC-blast furnace slag (BFS) and calcium aluminate cement (CAC) based systems. The total amount of aluminium able to corrode in an OPC and 4:1 BFS:OPC system was determined, and the correlation between the amount of calcium hydroxide in the system and the reaction of aluminium obtained. It was also shown that a CAC-based system could offer a potential matrix to incorporate aluminium metal with a further reduction of pH by introduction of phosphate, producing a calcium phosphate cement.

Kinoshita, Hajime, E-mail: h.kinoshita@sheffield.ac.uk [Department of Materials Science and Engineering, The University of Sheffield, Mappin Street, Sheffield, S1 3JD (United Kingdom)] [Department of Materials Science and Engineering, The University of Sheffield, Mappin Street, Sheffield, S1 3JD (United Kingdom); Swift, Paul; Utton, Claire [Department of Materials Science and Engineering, The University of Sheffield, Mappin Street, Sheffield, S1 3JD (United Kingdom)] [Department of Materials Science and Engineering, The University of Sheffield, Mappin Street, Sheffield, S1 3JD (United Kingdom); Carro-Mateo, Beatriz [The Public University of Navarra, C/Esquíroz, 30 trasera, Pamplona 31007 (Spain)] [The Public University of Navarra, C/Esquíroz, 30 trasera, Pamplona 31007 (Spain); Marchand, Geraldine [The National Institute of Applied Sciences (INSA) Lyon, 20 Avenue Albert Einstein 69621 Villeurbanne Cedex (France)] [The National Institute of Applied Sciences (INSA) Lyon, 20 Avenue Albert Einstein 69621 Villeurbanne Cedex (France); Collier, Nick [National Nuclear Laboratory, Chadwick House, Birchwood Park, Warrington, WA3 6AE (United Kingdom)] [National Nuclear Laboratory, Chadwick House, Birchwood Park, Warrington, WA3 6AE (United Kingdom); Milestone, Neil [Industrial Research Ltd., 69 Gracefield Road, Lower Hutt, 5040 (New Zealand)] [Industrial Research Ltd., 69 Gracefield Road, Lower Hutt, 5040 (New Zealand)

2013-08-15

188

Computer modelling of age hardening for cast aluminium alloys  

NASA Astrophysics Data System (ADS)

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.

Wu, Linda; Ferguson, W. George

2009-08-01

189

Contribution a l'etude du role de dopants dans la densification et la croissance cristalline du dioxyde d'uranium. (Effect of additives on enhanced sintering and grain growth in uranium dioxide).  

National Technical Information Service (NTIS)

The use of sintering additives has been the most effective way of promoting grain growth of uranium dioxide. We have established a same mechanism for additives which belongs to corundum structure: chromium, aluminium, vanadium and titanium sesquioxides. S...

L. Bourgeois

1992-01-01

190

Production of cast aluminium-graphite particle composites using a pellet method  

Microsoft Academic Search

Copper- and nickel-coated graphite particles can be successfully introduced into aluminium-base alloy melts as pellets to produce cast aluminium-graphite particle composites. The pellets were made by pressing mixtures of nickel- or copper-coated graphite particles and aluminium powders together at pressures varying between 2 and 20 kg mm-2. These pellets were dispersed in aluminium alloy melts by plunging and holding them

B. C. Pai; P. K. Rohatgi

1978-01-01

191

Process and Mechanical Properties: Applicability of a Scandium modified Al-alloy for Laser Additive Manufacturing  

NASA Astrophysics Data System (ADS)

The applicability of an aluminium alloy containing scandium for laser additive manufacturing (LAM) is considered. Modified aluminium alloys with a scandium content beyond the eutectic point offer great potential to become a high prioritized aerospace material. Depending on other alloying elements like magnesium or zirconium, strongly required weight reduction, corrosion resistance and improved strength properties of metallic light weight alloys can be achieved. The development, production and testing of parts built up by a laser powder bed process will be presented with regard to the qualification of the new material concept “ScalmalloyRP®” for laser additive manufacturing.

Schmidtke, K.; Palm, F.; Hawkins, A.; Emmelmann, C.

192

Nature of the active component of copper-zinc-aluminium catalyst for methanol synthesis  

Microsoft Academic Search

Comparative studies of the catalytic properties and thermal stability of a copper-zinc-aluminium catalyst and its components have revealed that the catalytic activity is determined by a solid solution of copper and aluminium in zinc oxide containing OH? and CO32? groups in its anion skeleton. The presence of aluminium in the solid solution ensures the increase of the catalyst thermal stability

L. I. Kuznetsova; T. M. Yurieva; T. P. Minyukova; S. V. Ketchik; L. M. Plyasova; G. K. Boreskov

1982-01-01

193

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

Microsoft Academic Search

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

Ramanujam Sarathi; Binu Sankar; Satyanarayanan R. Chakravarthy

2010-01-01

194

Stimulation of eryptosis by aluminium ions  

SciTech Connect

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.

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

195

The Burning Rate of Aluminium Particles in Cylinder Tests  

NASA Astrophysics Data System (ADS)

Aluminium is a common fuel component in propellants and explosives. There is a wealth of literature on Aluminium combustion in gases at relatively low pressure but limited data on combustion at high pressure (as in explosive detonation products). In this work we have carried out and analysed cylinder tests with Aluminium loaded explosives with a view to assessing the applicability of low pressure burning rates in this regime. The analysis makes use of detailed numerical two phase flow modelling and a range of experiments used to validate other relevant aspects of the physics, such as drag laws. We conclude that the burning rate is significantly faster than that implied by extrapolating laws applicable at lower pressures.

Evans, David J.; Milne, Alec M.; Softley, Ian

2002-07-01

196

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

NASA Astrophysics Data System (ADS)

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.

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

2005-12-01

197

Natural Honey as Corrosion Resistant for Aluminium Alloy  

NASA Astrophysics Data System (ADS)

The corrosion behaviour of AA6061 aluminium alloy in tropical seawater was investigated using weight loss measurement and electrochemical polarization technique. The electrochemical measurements showed that the presence of natural honey as corrosion resistant significantly decrease the corrosion current densities (icorr) and corrosion rates. It was observed that the inhibition efficiencies increased with the increasing concentrations of the resistant. Potentiodyanamic curves suggested that natural honey suppressed both cathodic and anodic processes. A good fit to Langmuir adsorption isotherm was obtained between the degree of surface coverage and the concentration of natural honey. It can be concluded that natural honey is an excellent corrosion resistant for aluminium alloy immersed in tropical seawater.

Rosliza, R.; Senin, H. B.; Muzathik, A. M.; Wan Nik, W. B.

2009-07-01

198

Soil aluminium uptake and accumulation by Paspalum notatum.  

PubMed

Paspalum notatum Flugge has been widely utilized for the purpose of ecological restoration of degraded land in the tropics and subtropics, where soil active aluminium (Al) is usually high as a result of acidification. Pot experiments were conducted to determine Al toxicity on P. notatum and to compare its potential to remove Al with another three plant species, Vetiveria zizanioides, Tristania conferta and Schima wallichii. In the Al addition experiment, the biomass of P. notatum and Al accumulation significantly decreased as the added Al concentration increased, but Al concentration in the plant markedly increased. A parallel experiment was conducted with the above four species, grown in lateritic soil and in oil shale waste containing high concentration of active Al. The biomasses of all four species were reduced obviously in the waste compared to in the soil. The effects of substrate on Al concentration, accumulation and translocation efficiency differed among species, and plants had significantly higher Al accumulation factors when grown in the soil than in the waste. Most of the Al taken up by P. notatum was transferred to above-ground parts; as a result, Al concentration in stems and leaves became quite high, over 1000 or even 3000 mg kg(-1); whereas for the other three species, Al concentration in shoots was much lower than in roots. Paspalum notatum was therefore much higher than the other three species with regard to Al translocation efficiency and therefore P. notatum may be regarded as both an effective Al hyper-accumulator and a potential Al hyper-remover. PMID:19423590

Huang, Juan; Xia, Hanping; Li, Zhi'an; Xiong, Yanmei; Kong, Guohui; Huang, Juan

2009-10-01

199

Occupational exposure to beryllium in primary aluminium production.  

PubMed

Alumina used in the production of primary aluminium contains Be which partly vaporises from the cryolite bath into the workroom atmosphere. Since Be may be toxic at lower exposure levels than previously thought, the personal exposure to Be among workers in 7 Norwegian primary smelters has been assessed. In total, 480 personal Respicon® virtual impactor full shift air samples have been collected during 2 sampling campaigns and analysed for water soluble Be, Al and Na using inductively coupled plasma optical emission spectrometry. In addition, water soluble F(-) has been measured by ion chromatography. The Be air concentrations in the inhalable, thoracic and respirable aerosol fractions have been calculated. The Be concentrations in the inhalable aerosol fraction vary between the different smelters. The highest GM concentration of Be in the inhalable fraction (122 ng m(-3), n = 30) was measured in the prebake pot room of a smelter using predominantly Jamaican alumina where also the highest individual air concentration of 270 ng m(-3) of Be was identified. The relative distribution of Be in the different aerosol fractions was fairly constant with the mean Be amount for the two sampling campaigns between 44-49% in the thoracic fraction expressed as % of the inhalable amount. Linear regression analysis shows a high correlation between water soluble Be, Al, F and Na describing an average measured chemical bulk composition of the water soluble thoracic fraction as Na(5.7)Al(3.1)F(18). Be is likely to be present as traces in this particulate matter by replacing Al atoms in the condensed fluorides and/or as a major element in a nanoparticle sized fluoride. Thus, the major amount of Be present in the work room atmosphere of Al smelter pot rooms will predominantly be present in combination with substantial amounts of water soluble Al, F and Na. PMID:21993554

Skaugset, Nils Petter; Ellingsen, Dag G; Dahl, Kari; Martinsen, Ivar; Jordbekken, Lars; Drabløs, Per Arne; Thomassen, Yngvar

2012-02-01

200

Do oral aluminium phosphate binders cause accumulation of aluminium to toxic levels?  

PubMed Central

Background Aluminium (Al) toxicity was frequent in the 1980s in patients ingesting Al containing phosphate binders (Alucaps) whilst having HD using water potentially contaminated with Al. The aim of this study was to determine the risk of Al toxicity in HD patients receiving Alucaps but never exposed to contaminated dialysate water. Methods HD patients only treated with Reverse Osmosis(RO) treated dialysis water with either current or past exposure to Alucaps were given standardised DFO tests. Post-DFO serum Al level > 3.0 ?mol/L was defined to indicate toxic loads based on previous bone biopsy studies. Results 39 patients (34 anuric) were studied. Mean dose of Alucap was 3.5 capsules/d over 23.0 months. Pre-DFO Al levels were > 1.0 ?mol/L in only 2 patients and none were > 3.0 ?mol/L. No patients had a post DFO Al levels > 3.0 ?mol/L. There were no correlations between the serum Al concentrations (pre-, post- or the incremental rise after DFO administration) and the total amount of Al ingested. No patients had unexplained EPO resistance or biochemical evidence of adynamic bone. Conclusions Although this is a small study, oral aluminium exposure was considerable. Yet no patients undergoing HD with RO treated water had evidence of Al toxicity despite doses equivalent to 3.5 capsules of Alucap for 2 years. The relationship between the DFO-Al results and the total amount of Al ingested was weak (R2 = 0.07) and not statistically significant. In an era of financial prudence, and in view of the recognised risk of excess calcium loading in dialysis patients, perhaps we should re-evaluate the risk of using Al-based phosphate binders in HD patients who remain uric.

2011-01-01

201

Aluminium uptake from some foods by guinea pigs and the characterization of aluminium in in vivo intestinal digesta by SEC-ICP-MS.  

PubMed

The uptake of ingested aluminium (Al) from food items commonly consumed in a normal human diet was investigated by feeding five test diets to guinea pigs. Al concentrations were measured in the femur, brain, kidney and upper intestinal contents. Consumption of these diets did not lead to elevated Al levels in brain. Levels of Al in the bone were elevated in animals fed sponge cake with a permitted Al-containing additive, and the presence of citrate as orange juice enhanced bone deposition and increased kidney Al levels. Less than 1% of Al in the upper intestinal contents was found in the soluble fraction, and characterization by SEC-ICP-MS indicated that this Al was not present as Al-citrate. PMID:8070734

Owen, L M; Crews, H M; Bishop, N J; Massey, R C

1994-08-01

202

Slurry sampling fluorination assisted electrothermal vaporization-inductively coupled plasma-atomic emission spectrometry for the direct determination of metal impurities in aluminium oxide ceramic powders.  

PubMed

A new analytical procedure for the direct determination of metal impurities (Cr, Cu, Fe and V) in aluminium oxide ceramic powders by slurry sampling fluorination assisted electrothermal vaporization-inductively coupled plasma-atomic emission spectrometry (ETV-ICP-AES) is reported. A polytetrafluoroethylene (PTFE) emulsion was used as a fluorinating reagent to promote the vaporization of impurity elements in aluminium oxide ceramic powders from the graphite tube. A vaporization stage with a long ramp time and a short hold time provided the possibility of temporal analyte-matrix separation. The experimental results indicated that a 10 microL 1% m/v slurry of aluminium oxide could be destroyed and vaporized completely with 600 micrograms PTFE under the selected conditions. Two aluminium oxide ceramic powder samples were used without any additional pretreatment. Analytical results obtained by using standard addition method with aqueous standard solution were checked by comparison of the results with pneumatic nebulization (PN)-ICP-AES based on the wet-chemical decomposition and analyte-matrix separation. The limits of detection (LODs) between 0.30 microgram g-1 (Fe) and 0.08 microgram g-1 (Cu) were achieved, and, the repeatability of measurements was mainly better than 10%. PMID:11270230

Peng, T; Chang, G; Wang, L; Jiang, Z; Hu, B

2001-03-01

203

Friction Stir Knead Welding of steel aluminium butt joints  

Microsoft Academic Search

To develop steel aluminium-tailored hybrids in a butt joint for sheets in a thickness of about 1mm conventional Friction Stir Welding is not feasible due to a high distortion of the welded specimen. Contrary to Friction Stir Welding the tool used for Friction Stir Knead Welding has no pin wherefore higher welding speeds can be realised. Due to the fact

M. Geiger; F. Micari; M. Merklein; L. Fratini; D. Contorno; A. Giera; D. Staud

2008-01-01

204

T-stub aluminium joints: influence of behavioural parameters  

Microsoft Academic Search

This paper is focused on the behaviour of aluminium alloy T-stub joints. The analysis is developed by means of finite element method simulation carried out with the non-linear code ABAQUS. The procedure has been accurately calibrated on the basis of some existing experimental results. The analysis, which has been referred to several behavioural parameters, has shown that, contrary to steel

G De Matteis; A Mandara; F. M Mazzolani

2000-01-01

205

LASERS IN MEDICINE: Two-photon excitation of aluminium phthalocyanines  

NASA Astrophysics Data System (ADS)

A demonstration is given of the feasibility of two-photon excitation of aluminium phthalocyanine and of the pharmaceutical preparation 'Fotosens', used in photodynamic therapy. The excitation source was an Nd:YAG laser emitting at the 1064 nm wavelength. The spectra of the two-photon-excited luminescence were obtained and the two-photon absorption cross sections were determined.

Meshalkin, Yu P.; Alfimov, E. E.; Vasil'ev, N. E.; Denisov, A. N.; Makukha, V. K.; Ogirenko, A. P.

1999-12-01

206

Aluminium hydride: a reversible material for hydrogen storage.  

PubMed

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

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

2009-07-01

207

Quenching residual stresses in 7060 aluminium alloy gas cylinder necks  

Microsoft Academic Search

A destructive technique under development to determine residual stresses in thick-walled pressure vessels has been employed to determine quenching residual stresses in 7060 aluminium alloy gas cylinder necks. The gas cylinders were supplied with interference fit collars attached to the apex of the gas cylinder neck. The effect the elastic interference fit stresses have on the quenching residual stresses in

D. J. Sharman; H. L. Stark; D. W. Kelly

1997-01-01

208

LASERS IN MEDICINE: Two-photon excitation of aluminium phthalocyanines  

Microsoft Academic Search

A demonstration is given of the feasibility of two-photon excitation of aluminium phthalocyanine and of the pharmaceutical preparation 'Fotosens', used in photodynamic therapy. The excitation source was an Nd:YAG laser emitting at the 1064 nm wavelength. The spectra of the two-photon-excited luminescence were obtained and the two-photon absorption cross sections were determined.

Yu P. Meshalkin; E. E. Alfimov; N. E. Vasil'ev; A. N. Denisov; V. K. Makukha; A. P. Ogirenko

1999-01-01

209

Manganese–nitrogen–sulphur surface layers produced on aluminium alloys  

Microsoft Academic Search

The main reason of the surface modification of the components such as pistons and cylinder blocks made of cast aluminium alloys is to obtain high hardness, wear and corrosion resistance of the working surface for larger lifetime of the motor-car and aircraft engines. In that aspect, the new conception of creating — by hybrid method — surface layers containing manganese,

W. Serbi?ski

2005-01-01

210

Tests on Individual Aluminium Plates Under In-Plane Compression.  

National Technical Information Service (NTIS)

Tests are reported on 76 aluminium plates with controlled initial out of flatness and residual stress. Two alloys were studied, namely 5083-M and 6082-TF. Some specimens were transversely welded. Their sizes ranged from 20 < b/t < 85, corresponding to a n...

D. S. Mofflin J. B. Dwight

1983-01-01

211

Pattern recognition in the automatic inspection of aluminium castings  

Microsoft Academic Search

In this paper, we report the results obtained recently by analysing around 400 features measured from 23.000 regions segmented in 50 radioscopic images of cast aluminium wheels with defects. The extracted features are divided into two groups: geometric features (area, perimeter, height, width, roundness, Fourier descriptors, invariant moments, and other shape factors) and grey value features (mean grey value, mean

Domingo Mery; Romeu R. da Silva; Luiz P. Calôba; João M. A. Rebello

2003-01-01

212

Carbon capture and the aluminium industry: preliminary studies  

Microsoft Academic Search

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

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

2006-01-01

213

Aluminium cycling in the soil-plant-animal-human continuum  

Microsoft Academic Search

A critical review of the literature on Al toxicity in plants, animals and humans reveals a similar mode of Al action in all living organisms, namely interference with the secondary messenger system (phosphoinositide and cytosolic Ca2+ signalling pathways) and enhanced production of reactive oxygen species resulting in oxidative stress. Aluminium uptake by plants is relatively quick (across the intact plasma

Z. Rengel

2004-01-01

214

A review on friction stir welding for aluminium alloys  

Microsoft Academic Search

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

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

2010-01-01

215

Determination of aluminium using high performance chelation ion chromatography.  

PubMed

The suitability of high performance chelation ion chromatography (HPCIC) using postcolumn reaction for the separation and determination of dissolved aluminium in complex samples was investigated. Use of a chelating ion-exchanger allowed for differentiation between kinetically labile and kinetically stable species of aluminium. Separation through a combination of chelation and cation-exchange was achieved using a 200 x 4.0 mm id column packed with particles of silica functionalised with iminodiacetic acid, with nitric acid-potassium chloride eluents. A temperature anomaly causing a five-fold increase in column efficiency for aluminium is believed to be a result of localised temperature effects in the particular type of instrument used. Postcolumn reagents investigated for the photometric detection included Tiron, Pyrocatechol Violet, Chrome Azurol S, and Eriochrome Cyanine R. The lowest detection limit (2.7 microg/L for a 100 microL sample volume) was achieved using 0.25 mM Eriochrome Cyanine R in 0.2 M hexamine (pH 6.1) with 1 mM cetyltrimethylpyridium bromide (CTAB). The optimised HPCIC system was applied successfully to the quantification of labile aluminium in paper mill process water. PMID:18563745

Tria, Juliette; Haddad, Paul R; Nesterenko, Pavel N

2008-07-01

216

Hot and warm forming of 2618 aluminium alloy  

Microsoft Academic Search

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

P Cavaliere

2002-01-01

217

Quench modification of aluminium-silicon eutectic alloys  

Microsoft Academic Search

Directional solidification of aluminium-silicon eutectic alloys were carried out in order to investigate the mechanism by which the quench modification takes place. For this purpose a new type of Bridgman furnace was designed which can attain a high temperature gradient and a high interfacial growth velocity up to 1000 µm-1. It is established that the fibrous structure is the result

S. Khan; R. Elliott

1996-01-01

218

Study on wear properties of aluminium–silicon piston alloy  

Microsoft Academic Search

Low expansion aluminium–silicon eutectic alloys are cast to produce most of the automotive pistons. The structure and properties of these alloys are very much dependent on the cooling rate, composition, modification and heat treatment operations. In this study, locally available automotive ‘scrap pistons’ were used as basic raw materials and a natural gas fired crucible furnace was used for melting

M. M. Haque; A. Sharif

2001-01-01

219

Severe wear of a near eutectic aluminium–silicon alloy  

Microsoft Academic Search

The severe wear of a near eutectic aluminium–silicon alloy is explored using a range of electron microscopic, spectroscopic and diffraction techniques to identify the residually strained and unstrained regions, microcracks and oxidized regions in the subsurface. In severe wear the contact pressure exceeds the elastic shakedown limit. Under this condition the primary and eutectic silicon particles fragment drastically. The fragments

Anirban Mahato; Nisha Verma; Vikram Jayaram; S. K. Biswas

2011-01-01

220

Structure of rapidly solidified aluminium-silicon alloys  

Microsoft Academic Search

This paper present results obtained on rapid solidification of aluminium-silicon alloys from the liquid state. It shows that the limit of primary solid solubility is extended almost to the eutectic composition and that the large supersaturation is relieved on raising the annealing temperature to the range 110 to 450° C. This conclusion is based on measurements of lattice parameter and

S. K. Bose; R. Kumar

1973-01-01

221

High Speed Face Milling of a Aluminium Silicon Alloy Casting  

Microsoft Academic Search

High speed machining of aluminium silicon alloy castings has gained significant interest from automotive industry involved in the development of the new generation of lightweight vehicles. This paper investigates the influence of workpiece microstructure, namely the secondary dendritic arm spacing (SDAS), tool material and geometry on tool wear mechanisms, cutting forces and surface integrity when face milling at cutting speeds

E-G Ng; D. Szablewski; M. Dumitrescu; M. A. Elbestawi; J. H. Sokolowski

2004-01-01

222

Annealing behaviour of aluminium-implanted InP  

NASA Astrophysics Data System (ADS)

The annealing behaviour of aluminium has been studied in single-crystal InP implanted with 40 and 120 keV 27Al + ions. The implantation doses were 1×10 15 and 1×10 16 cm-2. The aluminium concentration profiles were determined by two techniques, Secondary ion mass spectrometry (SIMS) and the nuclear resonance broadening technique (NRB) which was used for checking purposes. The usability of the SIMS technique for profiling Al rich layers was studied. Significant inconsistencies were observed in the SIMS profiles with the high dose implanted samples. The 120 keV, 1×10 16 cm -2 implanted samples were subject to annealing in argon atmosphere in the temperature range 380-600°C. Redistribution and a significant aluminium surface enrichment took place. The coefficients of Al migration were determined by fitting a concentration independent solution of the diffusion equation to the experimental depth profiles. The deduced activation energy and frequency factor for aluminium migration in implanted InP are 0.78 eV and 5.5×10 5 nm2/ s, respectively. The effect of defects on the Al migration is discussed. Rutherford backscattering (RBS) spectra measured along <1 0 0> channeling direction for 120 keV, 10 16 cm -2 implanted samples indicated a loss of crystalline structure near the surface both in the as-implanted and in the annealed samples.

Kyllönen, V.; Räisänen, J.; Seppälä, A.; Ahlgren, T.; Likonen, J.

2000-03-01

223

Galvanic corrosion of laser weldments of AA6061 aluminium alloy  

Microsoft Academic Search

Galvanic corrosion of laser welded AA6061 aluminium alloy, arising from the varying rest potentials of the various weldment regions, was examined. The weld fusion zone is found to be the most cathodic region of the weldment while the base material is the most anodic region. The rate of galvanic corrosion, controlled by the cathodic process at the weld fusion zone,

A. B. M. Mujibur Rahman; S. Kumar; A. R. Gerson

2007-01-01

224

Crash and structural analyses of an aluminium railroad passenger car  

Microsoft Academic Search

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,

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

2012-01-01

225

The effects of ionic strength on the toxicity of aluminium to Atlantic salmon (Salmo salar) under non-steady state chemical conditions  

Microsoft Academic Search

We have tested the influence of water ionic strength on the toxicity of aluminium in fish by comparing the mortality of Atlantic salmon (Salmo salar) parr exposed to Al-rich water with additions of Ca2+ or Na+. The fish were exposed in parallel to Al-rich water (Al 500 µg l-1, pH 5.8) under non-steady state conditions, with and without the addition

Espen LYDERSEN; Sigurd ØXNEVAD; Ronny A. ANDERSEN; Frode BJERKELY; Leif Asbjørn VØLLESTAD

2002-01-01

226

Aspects of the bioinorganic chemistry of silicon in conjunction with the biometals calcium, iron and aluminium.  

PubMed

Silicon, in its various forms (silicic acid (Si(OH)4) through to hydrated amorphous silica (SiOn(OH)4-2n, n = 2-4) is important in geological and biological processes. Silicon is considered to be an 'essential' element for some plants and higher animals and when present as silica imparts structural, defensive and photosynthetic advantages to many plants. For the majority of essential elements specific molecular binding sites have been identified, but this is not the case for silicon. This has lead to the proposal that silicon may not act directly on biological systems but may exert its influence via interactions with biometals. Metals for which this may be a viable option include aluminium, iron and calcium, all of which can be found co-located with silicon in both minerals and living organisms. This article briefly reviews the pertinent solution and solid state chemistry of silicon in relation to aluminium, iron and calcium. Examples where silicon and an additional metal are found in solid state phases are described. The biological systems where these deposits are found are extremely complex and preliminary results from a model system designed to study silicon-biometal interactions are described. PMID:9629678

Perry, C C; Keeling-Tucker, T

1998-02-15

227

An ellipsometry study on the effect of aluminium chloride and ferric chloride formulations on mucin layers adsorbed at hydrophobic surfaces.  

PubMed

Ellipsometry was used to investigate the effect of polyaluminium chloride (PAC) formulations of different degrees of hydrolysation on an adsorbed mucin film. The results were compared to the effect of aluminium chloride (AlCl(3)) and ferric chloride. A compaction of the mucin film took place upon addition of the formulations and this occurred to different extents and at different concentrations for the different formulations. The compaction of PAC of a low degree of hydrolysis behaved similarly to AlCl(3). PAC of a high degree of hydrolysis showed a greater compaction effect than the other aluminium formulations. The initial compaction concentration was found to be 0.001 mM which is less than previously found for aluminium-mucin complex formation in bulk. The reversibility of the compaction was also investigated. The compaction of the mucin film was found to be partly reversible for AlCl(3) and PAC of low degree of hydrolysis. No reversibility was observed for the formulations of PAC of high hydrolysis grade or for ferric chloride. The results are consistent with previously observed effects of PAC of a low degree of hydrolysis on bacterial surfaces where a compaction of surface polymers was indicated by the reduced range of repulsive steric interactions. PMID:20432077

Hamit-Eminovski, Jildiz; Eskilsson, Krister; Arnebrant, Thomas

2010-07-01

228

Effect of Aluminium Ions on Covalent Behaviour of Li2CO3-B2O3 Glasses  

NASA Astrophysics Data System (ADS)

The paper undertakes the preparation of Aluminium oxide doped Lithium borate glasses and characterizes to investigate the physical and optical studies of these glasses using density and UV-Visible spectroscopy. Results had been obtained with the help of FTIR Spectra in our previous work which indicate that Al2O3 acts as a network modifier by converting three coordinated boron atoms [BO3] to four coordinated boron atoms [BO4]. The effect of aluminium content on the optical properties of the present glass system has been studied from the optical absorption spectra. It shows the shifting of the band edge towards the higher wavelength and that there is corresponding decrease in the band gap, which is due to the conversion of BO3 to BO4 units. The evaluation of the compact structure of prepared glass samples with the presence of [BO4] groups has been made in terms of the physical properties such as density and molar volume. It is also confirmed by average boron-boron separation results. The research findings confirm that the addition of Aluminium oxide increases the covalent value and corresponding decrease in ionicity behaviour.

Pal Singh, Gurinder; Kaur, Parvinder; Kaur, Simranpreet; Arora, Deepa Wali; Sharma, Mohandeep; Singh, D. P.

229

Standardization and validation of a new atomic absorption spectroscopy technique for determination and quantitation of aluminium adjuvant in immunobiologicals.  

PubMed

In the present study, Aluminium quantification in immunobiologicals has been described using atomic absorption spectroscopy (AAS) technique. The assay was found to be linear in 25-125 microg/ml Aluminium range. The procedure was found to be accurate for different vaccines with recoveries of external additions ranging between 93.26 and 103.41%. The mean Limit of Variation (L.V.) for both intra- and inter-assay precision was calculated to be 1.62 and 2.22%, respectively. Further the procedure was found to be robust in relation to digestion temperature, alteration in acid (HNO(3) and H(2)SO(4)) ratio used for sample digestion and storage of digested vaccine samples up to a period of 15 days. After validation, AAS method was compared for its equivalency with routinely used complexometric titration method. On simultaneously applying on seven different groups of both bacterial and viral vaccines, viz., DPT, DT, TT, Hepatitis-A and B, Antirabies vaccine (cell culture) and tetravalent DPT-Hib, a high degree of positive correlation (+0.85-0.998) among AAS and titration methods was observed. Further AAS method was found to have an edge over complexometric titration method that a group of vaccines, viz., ARV (cell culture, adsorbed) and Hepatitis-A, in which Aluminium estimation is not feasible by pharmacopoeial approved complexometric titration method (possibly due to some interference in the sample matrix), this newly described and validated AAS assay procedure delivered accurate and reproducible results. PMID:17644407

Mishra, Arti; Bhalla, Sumir Rai; Rawat, Sameera; Bansal, Vivek; Sehgal, Rakesh; Kumar, Sunil

2007-10-01

230

Protective effect of curcumin (Curcuma longa), against aluminium toxicity: Possible behavioral and biochemical alterations in rats.  

PubMed

Aluminium is a potent neurotoxin and has been associated with Alzheimer's disease (AD) causality for decades. Prolonged aluminium exposure induces oxidative stress and increases amyloid beta levels in vivo. Current treatment modalities for AD provide only symptomatic relief thus necessitating the development of new drugs with fewer side effects. The aim of the study was to demonstrate the protective effect of chronic curcumin administration against aluminium-induced cognitive dysfunction and oxidative damage in rats. Aluminium chloride (100 mg/kg, p.o.) was administered to rats daily for 6 weeks. Rats were concomitantly treated with curcumin (per se; 30 and 60 mg/kg, p.o.) daily for a period of 6 weeks. On the 21st and 42nd day of the study behavioral studies to evaluate memory (Morris water maze and elevated plus maze task paradigms) and locomotion (photoactometer) were done. The rats were sacrificed on 43rd day following the last behavioral test and various biochemical tests were performed to assess the extent of oxidative damage. Chronic aluminium chloride administration resulted in poor retention of memory in Morris water maze, elevated plus maze task paradigms and caused marked oxidative damage. It also caused a significant increase in the acetylcholinesterase activity and aluminium concentration in aluminium treated rats. Chronic administration of curcumin significantly improved memory retention in both tasks, attenuated oxidative damage, acetylcholinesterase activity and aluminium concentration in aluminium treated rats (P<0.05). Curcumin has neuroprotective effects against aluminium-induced cognitive dysfunction and oxidative damage. PMID:19616038

Kumar, Anil; Dogra, Samrita; Prakash, Atish

2009-12-28

231

Fluxless laser brazing of aluminium alloy to galvanized steel using a tandem beam – dissimilar laser brazing of aluminium alloy and steels  

Microsoft Academic Search

Tandem beam brazing with aluminium filler metal (BA4047) was conducted in order to develop the fluxless laser brazing technique of aluminium alloy (AA6022) to galvanized steels (GA and GI steels). Laser powers of tandem beam and offset distance of preheating beam from the root to the steel base metal were varied. Sound braze beads could be obtained by optimizing the

Kazuyoshi Saida; Haruki Ohnishi; Kazutoshi Nishimoto

2010-01-01

232

Recovery of the actinides by electrochemical methods in molten chlorides using solid aluminium cathode  

SciTech Connect

An electrorefining process in molten chloride salts is being developed at ITU to reprocess the spent nuclear fuel. According to the thermochemical properties of the system, aluminium is the most promising electrode material for the separation of actinides (An) from lanthanides (Ln). The actinides are selectively reduced from the fission products and stabilized by the formation of solid and compact actinide-aluminium alloys with the reactive cathode material. In this work, the maximum loading of aluminium with actinides was investigated by potentiostatic and galvano-static electrorefining of U-Pu- Zr alloys. A very high aluminium capacity was achieved, as the average loading was 1.6 g of U and Pu into 1 g of aluminium and the maximum achieved loading was 2.3 g. For recovery of the actinides from aluminium, a process based on chlorination and a subsequent sublimation of AlCl{sub 3} is proposed. (authors)

Malmbeck, R.; Mendes, E.; Serp, J.; Soucek, P.; Glatz, J.P. [European Commission, JRC, Institute for Transuranium Elements, Postfach 2340, 76125 Karlsruhe (Germany); Cassayre, L. [Laboratoire de Genie Chimique - LGC, Universite Paul Sabatier, UMR 5503, 118 route de Narbonne, 31062 Toulouse Cedex 04 (France)

2007-07-01

233

Crystal morphology of unmodified aluminium-silicon eutectic microstructures  

NASA Astrophysics Data System (ADS)

The crystallography of eutectic silicon in an unmodified A1-12.7 wt% Si alloy has been studied by transmission electron microscopy and diffraction of thin films cut from bulk samples. Twinning mechanisms are described by which the silicon changes direction or adjusts interflake spacing at the solid-liquid interface. The branching mechanism observed by previous workers is confirmed but found to be infrequent at moderate freezing rates. A side-branching mechanism is described which is considered to be the primary mechanism for branching in the wheatsheaf configuration. Orientation relationships between the eutectic silicon and aluminium phases are described. These differ from those previously observed in thin films drawn from the melt. It is proposed that orientation relationships vary with freezing rate. Evidence is presented that the eutectic aluminium re-nucleates repeatedly during growth of a single eutectic grain.

Shamsuzzoha, M.; Hogan, L. M.

1986-08-01

234

Results of the Experiment: Welding of Aluminium Alloy in Microgravity  

NASA Astrophysics Data System (ADS)

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.

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

2002-01-01

235

Aluminium grain boundary diffusion in polycrystalline mullite ceramics  

NASA Astrophysics Data System (ADS)

Aluminium tracer diffusivities were measured in polycrystalline mullite. The artificial aluminium isotope 26Al was used as tracer isotope. An advanced preparation technique for the 26Al2O3 tracer source allowed to apply secondary ion mass spectrometry (SIMS) in order to analyse 26Al depth distributions in the polycrystalline material. Pre-exponential factors and activation enthalpies were determined for compositions of 78 wt.% Al2O3, 22 wt.% SiO2 (high-alumina material) and of 72 wt.% Al2O3, 28 wt.% SiO2 (low-alumina material), respectively. A strong dependence of the 26Al grain boundary diffusivity on the composition is observed. The results are discussed in comparison to previous data on grain boundary diffusivities of oxygen in mullite samples from the same batch.

Fielitz, P.; Borchardt, G.; Schmücker, M.; Schneider, H.

2007-08-01

236

The wear of wrought aluminium alloys under dry sliding conditions  

Microsoft Academic Search

The sliding wear response of several wrought aluminium alloys (2124, 3004, 5056 and 6092) against a high purity alumina (99.9%) counterface was investigated, at a fixed sliding speed of 1m\\/s and a load range of 23–140N. The counterface was chosen so as to minimise the chemically driven aspects of adhesive wear. Severe wear was observed at all loads, with specific

M. J. Ghazali; W. M. Rainforth; H. Jones

2007-01-01

237

Electrochemical behaviour of aluminium\\/steel rivet joints  

Microsoft Academic Search

The galvanic corrosion behaviour of a rivet joint of two sheets of the aluminium alloys EN AW-6014-T4 and EN AW-6082-T5 joined by an electrogalvanized steel blind rivet was investigated. The potentiodynamic polarization curves in a 5 wt.% NaCl solution show a potential reversion of the anodic and cathodic regions of the rivet joint. The surface potential was investigated with a

L. Krüger; M. Mandel

2011-01-01

238

Reducing residual stress in 2014 aluminium alloy die forgings  

Microsoft Academic Search

Closed die forgings manufactured from 2014 aluminium alloys have been subject to both standard and non-standard heat treatments in order to reduce the as-quenched residual stress magnitudes. Warm water (60°C) and boiling water quenches are investigated. The influence of changing the surface finish of the forgings during boiling water quenching on the mechanical properties and residual stress has also been

D. A. Tanner; J. S. Robinson

2008-01-01

239

Particle effects on friction and wear of aluminium matrix composites  

Microsoft Academic Search

Particle effects on friction and wear of 6061 aluminium (6061 Al) reinforced with silicon carbide (SiC) and alumina (Al2O3) particles were investigated by means of Vickers microhardness measurements and scratch tests. Unreinforced 6061 Al matrix alloy was also studied for comparison. To explore the effect of heat treatment, materials subjected to three different heat treatment conditions, i.e. under-aged, over-aged and

Z. F. Zhang; L. C. Zhang; Y.-W. Mai

1995-01-01

240

Low velocity perforation of AA5083-H116 aluminium plates  

Microsoft Academic Search

This paper presents an experimental and numerical investigation on low velocity perforation (in the velocity range 3.5–15.8m\\/s) of AA5083-H116 aluminium plates. In the tests, square plates were mounted in a circular frame and penetrated by a cylindrical blunt-nosed projectile. The perforation process was then computer analysed using the nonlinear finite element code LS-DYNA in order to investigate the effects of

F. Grytten; T. Børvik; O. S. Hopperstad; M. Langseth

2009-01-01

241

Aluminium foam–polymer composites: processing and characteristics  

Microsoft Academic Search

Dissemination of closed cell metal foam unique properties (low density, efficient energy absorption, high vibration\\/sound\\u000a attenuation) in real life products has often been difficult to realise. With advanced pore morphology (APM) aluminium foam–polymer\\u000a hybrids a new and simplified process route targeted at application in foam-filled structures (e.g. automotive A-pillar) has\\u000a been introduced. APM foams are made from spherical, small volume

Karsten Stöbener; Gerald Rausch

2009-01-01

242

Chromate conversion coatings on aluminium: influences of alloying  

Microsoft Academic Search

The growth kinetics of chromate\\/fluoride conversion coatings are examined for 99.99% aluminium, and Al–2.3at.%Cu, Al–1.9at.%Au and Al–20at.%Au alloys. The thickening of coatings and thinning of substrates, the latter deposited by magnetron sputtering, are determined by transmission electron microscopy. The results reveal consumption of substrates during the coating process, to the maximum immersion time of 24 min. Initial relatively rapid thinning

Y. Liu; P. Skeldon; G. E. Thompson; H. Habazaki; K. Shimizu

2004-01-01

243

Describing the plastic deformation of aluminium softball bats  

Microsoft Academic Search

Hollow aluminium bats were introduced over 30 years ago to provide improved durability over wooden bats. Since their introduction,\\u000a however, interest in hollow bats has focused almost exclusively around their hitting performance. The aim of this study was\\u000a to take advantage of the progress that has been made in predicting bat performance using finite elements and apply it to describe

Eric Biesen; Lloyd Smith

2007-01-01

244

Neurotoxic effects of aluminium on embryonic chick brain cultures  

Microsoft Academic Search

Toxic damage of brain cells by aluminium (A1) is discussed as a possible factor in the development of neurodegenerative disorders in humans. To investigate neurotoxic effects of A1, serum-free cultures of mechanically dissociated embryonic chick (stage 28–29) forebrain, brain stem and optic tectum, and for comparison meningeal cells, were treated with A1 (0–1000 M) for 7 days. Effects of A1

Judith Pia Miiller; Arend Bruinink

1994-01-01

245

Abrasive wear behaviour of SiC\\/2014 aluminium composite  

Microsoft Academic Search

Aluminium alloy matrix reinforced with 15wt% SiC particles were prepared by powder metallurgy (PM) method. Wear behaviour of the composite was investigated to find out effects of operating variables and hardness in terms of the Taguchi approach, on a pin-on-disc machine and compared with the previous work on the composite produced by liquid metallurgy method [1]. Analysis of variance (ANOVA)

Yusuf ?ahin

2010-01-01

246

Aluminium and lead: molecular mechanisms of brain toxicity  

Microsoft Academic Search

The fact that aluminium (Al) and lead (Pb) are both toxic metals to living organisms, including human beings, was discovered\\u000a a long time ago. Even when Al and Pb can reach and accumulate in almost every organ in the human body, the central nervous\\u000a system is a particular target of the deleterious effects of both metals. Select human population can

Sandra V. Verstraeten; Lucila Aimo; Patricia I. Oteiza

2008-01-01

247

Effect of atmospheres on the thermal stability of aluminium titanate  

Microsoft Academic Search

Aluminium titanate (Al2TiO5) is a promising engineering material because of its low thermal expansion coefficient, excellent thermal shock resistance, good refractoriness and non-wetting with most metals. However, it is susceptible to thermal dissociation in the temperature range ˜1100 1300 °C which degrades its desirable properties. In this work, the effect of atmospheres (i.e., air, argon, 50% oxygen\\/50% argon) on the

I. M. Low; Z. Oo; B. H. O'Connor

2006-01-01

248

Effect of atmospheres on the thermal stability of aluminium titanate  

Microsoft Academic Search

Aluminium titanate (Al2TiO5) is a promising engineering material because of its low thermal expansion coefficient, excellent thermal shock resistance, good refractoriness and non-wetting with most metals. However, it is susceptible to thermal dissociation in the temperature range ?1100–1300°C which degrades its desirable properties. In this work, the effect of atmospheres (i.e., air, argon, 50% oxygen\\/50% argon) on the isothermal stability

I. M. Low; Z. Oo; B. H. O’Connor

2006-01-01

249

A numerical study of MSD in aluminium alloys  

Microsoft Academic Search

This paper uses the finite element alternating technique to study the effect of multiple cracks, i.e. multi-site damage (MSD), in an aluminium alloy plate. This problem arose as a result of MSD seen in the aft bulkhead of F\\/A-18 aircraft in service with the Royal Australian Air force (RAAF). For the particular problem under investigation, it is shown that the

R. Jones; S. Hammond; J. F. Williams; M. Heller

1995-01-01

250

Modelling of aluminium sheet material at elevated temperatures  

Microsoft Academic Search

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

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

2004-01-01

251

Aluminium alloy-silica sand composites: preparation and properties  

Microsoft Academic Search

Ceramic particulate composites containing up to 25 wt% silica sand in commercially pure aluminium (LM-O) and its eutectic silicon alloy (LM-6) were prepared by liquid metallurgy techniques. Pre-treated sand particles of sizes ranging from -180 to +90µm were added to the alloy melts, followed by pouring the resulting mix into permanent moulds. Quantitative metallographic examination revealed that sand particles were

A. K. Gupta; T. K. Dan; P. K. Rohatgi

1986-01-01

252

Primary Silicon Spherulites in Aluminium-Silicon Alloys  

Microsoft Academic Search

WHEN metallic sodium is added to a eutectic aluminium-silicon alloy, the structure of the eutectic silicon is modified by a mechanism which has been described by several authors1-4. Sodium also modifies the structure of primary silicon crystals in this system, and various workers1,5 have stated that a spheroidal form of silicon can be obtained by this means. Evidence that these

M. G. Day

1968-01-01

253

Aluminium alloy-silica sand composites: preparation and properties  

Microsoft Academic Search

Ceramic particulate composites containing up to 25 wt% silica sand in commercially pure aluminium (LM-O) and its eutectic\\u000a silicon alloy (LM-6) were prepared by liquid metallurgy techniques. Pre-treated sand particles of sizes ranging from ?180\\u000a to +90?m were added to the alloy melts, followed by pouring the resulting mix into permanent moulds. Quantitative metallographic\\u000a examination revealed that sand particles were

A. K. Gupta; T. K. Dan; P. K. Rohatgi

1986-01-01

254

Structure of rapidly solidified aluminium-silicon alloys  

Microsoft Academic Search

This paper present results obtained on rapid solidification of aluminium-silicon alloys from the liquid state. It shows that\\u000a the limit of primary solid solubility is extended almost to the eutectic composition and that the large supersaturation is\\u000a relieved on raising the annealing temperature to the range 110 to 450 C. This conclusion is based on measurements of lattice\\u000a parameter and

S. K. Bose; R. Kumar

1973-01-01

255

Mechanical testing of steel\\/aluminium–silicon interfaces by pushout  

Microsoft Academic Search

The functionality of structural light alloy castings can be improved by inserting into them, upon moulding, local iron base reinforcements. To acquire a better knowledge of such bimetallic assemblies, samples were prepared by immersing a mild steel bar (5mm in diameter) in aluminium base Al–Si alloy melts held at 730°C. After melt solidification, the bimetallic samples were cut into 5mm

O. Dezellus; B. Digonnet; M. Sacerdote-Peronnet; F. Bosselet; D. Rouby; J. C. Viala

2007-01-01

256

Mercury cementation from chloride solutions using iron, zinc and aluminium  

Microsoft Academic Search

The main purpose of this work was to study the cementation of mercury (HgCl42) in a chloride medium using metallic zinc, iron and aluminium as reducing agents.The reaction order was 1.08±0.05 with respect to mercury concentration. The reaction efficiency is strongly dependent on pH. For each metal in study, an ideal pH was established: 4.0 to 5.0 for zinc, 3.0

A. L. Anacleto; J. R. Carvalho

1996-01-01

257

Discharge characterization in plasma electrolytic oxidation of aluminium  

Microsoft Academic Search

Digital video imaging of the plasma electrolytic oxidation (PEO) of aluminium has been performed, which allowed evaluation of both dimensional characteristics of individual microdischarges appearing at the oxide-electrolyte interface and their collective behaviour throughout the oxidation process. It has been shown that the microdischarge cross-sectional dimensions vary within the range 0.01-1.35 mm2. In the course of PEO processing, small localized

A. L. Yerokhin; L. O. Snizhko; N. L. Gurevina; A. Leyland; A. Pilkington; A. Matthews

2003-01-01

258

Spectroscopic characterization of plasma during electrolytic oxidation (PEO) of aluminium  

Microsoft Academic Search

We present results of an optical emission spectroscopic study of Plasma during Electrolytic Oxidation (PEO) of aluminium in citric acid and in sodium–tungstate water solutions. The line shape analysis of the first two hydrogen Balmer lines indicates presence of two PEO processes characterized by relatively low electron number densities Ne?0.8×1015cm?3 and at 2.5×1016cm?3. Apart from these two Ne values, Ne?6.0×1016cm?3

J. Jovovi?; S. Stojadinovi?; N. M. Šišovi?; N. Konjevi?

2011-01-01

259

The effect of casting temperature on the properties of squeeze cast aluminium and zinc alloys  

Microsoft Academic Search

Gravity casting and squeeze casting were carried out on an aluminium alloy with 13.5% silicon and a zinc alloy with 4.6% aluminium with different temperatures, 660, 690 and 720°C for the former and 440, 460 and 480°C for the latter. A top-loading crucible furnace was used to melt the alloys. The die-preheat temperatures used were 200–220°C for the aluminium alloy

L. J. Yang

2003-01-01

260

Characteristics of several carbon fibrereinforced aluminium composites prepared by a hybridization method  

Microsoft Academic Search

The properties and microstructures of several high-strength and high-modulus carbon fibrereinforced aluminium or aluminium alloy matrix composites (abbreviated as HSCF\\/Al and HMCF\\/Al, respectively, for the two types of fibre) have been characterized. The composites evaluated were fabricated by pressure casting based on a hybridization method. It was found that the strength degradation of high-modulus carbon fibres after infiltration of aluminium

H. M. Cheng; A. Kitahara; S. Akiyama; K. Kobayashi; Y. Uchiyama; B. L. Zhou

1994-01-01

261

Residual stresses in laser welded aluminium plate by use of ultrasonic and optical methods  

Microsoft Academic Search

With the wide application of aluminium alloys to the automotive, aerospace and other industries, laser welding has become a critical joining technique for aluminium alloys. In this paper, two techniques have been used to measure the non-uniform residual stresses in laser-welded aluminium alloys, i.e. the Lcr ultrasonic technique and the moiré interferometry incremental hole-drilling (MIIHD) method. The non-uniform residual stress

M. Ya; P. Marquette; F. Belahcene; J. Lu

2004-01-01

262

Phonon-limited resistivity of aluminium using a first-principles pseudopotential  

Microsoft Academic Search

The phonon-limited resistivity of aluminium has been calculated using a local, first-principles pseudopotential which has been useful in the calculation of other properties of aluminium. This pseudopotential is obtained from the induced electron density around an aluminium ion in an electron gas. From this pseudopotential, the interionic potential, the phonons (which are calculated by the self-consistent harmonic approximation) and finally

G. J. Vazquez; L. F. Magana

1990-01-01

263

Effect of oxide particles on the stabilization and final microstructure in aluminium  

PubMed Central

Bulk aluminium samples containing alumina particles have been produced by different severe plastic deformation methods. Aluminium foils with different initial foil thicknesses were cold rolled to different amounts of strain and aluminium powders were consolidated and deformed by high pressure torsion (HPT). During processing, alumina particles from the foil or particle surface are easily incorporated and dispersed in the bulk material. The influence of these alumina particles on the developing microstructures and the mechanical properties has been studied.

Bachmaier, Andrea; Pippan, Reinhard

2011-01-01

264

Violet-blue photoluminescence in aluminium oxide films prepared by ultrasonic spray pyrolysis  

Microsoft Academic Search

Violet-blue photoluminescent emission has been observed in aluminium oxide films deposited by the ultrasonic spray pyrolysis process at atmospheric pressure, using solutions of 0.05M aluminium acetylacetonate in a mixture of two parts of deionised water and two parts of methanol and aluminium chloride in the same solvent mixture. The films were deposited at substrate temperatures in the range from 240

A. Ortiz; J. C Alonso; V Pankov; D Albarran

1999-01-01

265

Herstellung und Umformbarkeit walzplattierter Magnesium(AZ31)Aluminium(1050)-Verbunde  

Microsoft Academic Search

\\u000a Summary  A possibility to reduce weight in lightweight constructions is the usage of magnesium instead of the typically used leight-weight\\u000a material aluminium. Magnesium is more than 30 % lighter than aluminium. However, the biggest problem of magnesium is the bad\\u000a corrosion behaviour. One approach of corrosion protection is coating with aluminium by roll-bounding. This paper gives an\\u000a introduction into the assembly

Carina Maria Schlögl; Clemens Planitzer; Otto Harrer; Bruno Buchmayr

2011-01-01

266

Erosion of aluminium-based claddings on steel by sand in water  

Microsoft Academic Search

This paper describes the slurry erosion of a range of HVOF deposited aluminium-based claddings on steel by sand in water. Coatings, approximately 300?m thick, of commercially pure aluminium, eutectic aluminium\\/silicon alloy (12%) and of a novel composite incorporating alumina in this alloy have been tested, both as sprayed and as ground to remove surface roughness as far as possible. Angular

A. J Speyer; R. J. K Wood; K. R Stokes

2001-01-01

267

Effect of ultrasonic energy on nanoscale interfacial structure in copper wire bonding on aluminium pads  

NASA Astrophysics Data System (ADS)

The effect of ultrasonic vibration on nanoscale interfacial structure of thermosonic copper wire bonding on aluminium pads was investigated. It was found that bonding strength was determined by the extent of fragmentation of a native aluminium oxide overlayer (5-10 nm thick) on aluminium pads, forming paths for formation of intermetallic compound CuAl2 in areas of direct contact of bonded metal surfaces. The degree of fracture of the oxide layer was strongly affected by a level of ultrasonic power.

Xu, H.; Liu, C.; Silberschmidt, V. V.; Chen, Z.; Acoff, V. L.

2011-04-01

268

Use of vermicompost extract as an aluminium inhibitor in aqueous solutions  

Microsoft Academic Search

Vermicompost extract (VCE) demonstrated the ability to raise the measured pH level of an acid soil thus showing a potential to limit aluminium toxicity. The relatively high proportion of humic substances (60% of VCE solid matter) suggested the possibility of formation of stable chelates with aluminium ions. A rate?based colorimetric method was utilised measuring at 585 nm the aluminium?pyrocatechol violet

D. Alter; A. Mitchell

1992-01-01

269

Thick gradient layers prepared by plasma-based ion implantation on 2024 aluminium alloy  

NASA Astrophysics Data System (ADS)

AlN/Ti/TiN/DLC layers more than 1 µm thick have been prepared by plasma-based ion implantation sequentially with nitrogen/titanium/nitrogen and titanium/carbon on 2024 aluminium alloy. On the basis of our previous AlN/Ti/TiN/DLC layers, new AlN/Ti/TiN/DLC layers thicken by thickening the 'TiN' layer and the diamond-like (DLC) film. The structures of the new layers have been characterized by XPS, AFM and Raman spectrum. The new layers exhibit improved composition and structure gradients at the interface in addition to a thicker 'TiN' layer and DLC film than the previous ones and hence display significant improvements in surface hardness and tribological properties. Also, their surface topography, DLC structure, nanohardness, stress and tribological properties as a function of the DLC film thickness have been discussed.

Liao, J. X.; Tian, Z.; Li, E. Q.; Xu, J.; Jin, L.; Yang, H. G.

2007-08-01

270

Theoretical aspects of fluoride air contaminant formation in aluminium smelter potrooms.  

PubMed

The amount of particulate fluorides evolved from aluminium electrolysis cells is not entirely accounted for by the fluorides entrained in the anode gas. The largest additional source of particulate fluoride formation is by direct evaporation of fluorides into the anode gas stream and subsequent condensation on the drops of electrolyte generated in the process of bubble burst. A theoretical model was used for the calculation of the main physical parameters responsible for the formation of particle nuclei when the hot anode-gas is mixed with ambient air. The results of these calculations are in agreement with experimental observations reported in the literature. In particular, the size distribution, composition and morphology of the nano-particles support the theory of a vapour condensation mechanism under conditions of extreme supersaturation, but further studies are necessary. PMID:15877162

L'vov, Boris V; Polzik, Leonid K; Weinbruch, Stephan; Ellingsen, Dag G; Thomassen, Yngvar

2005-05-01

271

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

SciTech Connect

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 primary and eutectic silicon crystals, and their possible synergistic influence, provide useful data on the critical stages of formation and growth of eutectic silicon phase. The nucleation and growth of eutectic silicon, removed from the cooperative precipitation zone, induce refinement in crystal size and, therefore, an improvement of the mechanical properties of the moulded structure. The aim of this investigation was to observe the influence of primary silicon crystals on the nucleation and growth of eutectic silicon.

Criado, A.J.; Martinez, J.A.; Calabres, R. [Complutense Univ. of Madrid (Spain). Dept. of Materials Science and Metallurgical Engineering] [Complutense Univ. of Madrid (Spain). Dept. of Materials Science and Metallurgical Engineering

1997-01-01

272

Model of Non-premixed Combustion of Aluminium---Air Mixtures  

NASA Astrophysics Data System (ADS)

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 equations, the solver finds iteratively the mixture pressure and temperature; in addition it furnishes a complete description of chemical and physical transformations. 2D numerical simulations give encouraging agreement with experimental pressure histories recorded on the chamber wall. It is shown that multiple blast wave reflections from the walls of the chamber strongly accelerate particle burning. The results demonstrate the advantages of the equilibrium EOS model and appeal for 3D AMR calculations on massively-parallel computers, which should better define the initial stage of turbulent particle dissemination.

Khasainov, Boris; Kuhl, Allen; Victorov, Sergey; Neuwald, Peter

2005-07-01

273

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

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

274

High rate constitutive modeling of aluminium alloy tube  

NASA Astrophysics Data System (ADS)

As the need for fuel efficient automobiles increases, car designers are investigating light-weight materials for automotive bodies that will reduce the overall automobile weight. Aluminium alloy tube is a desirable material to use in automotive bodies due to its light weight. However, aluminium suffers from lower formability than steel and its energy absorption ability in a crash event after a forming operation is largely unknown. As part of a larger study on the relationship between crashworthiness and forming processes, constitutive models for 3mm AA5754 aluminium tube were developed. A nominal strain rate of 100/s is often used to characterize overall automobile crash events, whereas strain rates on the order of 1000/s can occur locally. Therefore, tests were performed at quasi-static rates using an Instron test fixture and at strain rates of 500/s to 1500/s using a tensile split Hopkinson bar. High rate testing was then conducted at rates of 500/s, 1000/s and 1500/s at 21circC, 150circC and 300circC. The generated data was then used to determine the constitutive parameters for the Johnson-Cook and Zerilli-Armstrong material models.

Salisbury, C. P.; Worswick, M. J.; Mayer, R.

2006-08-01

275

Stock dynamics and emission pathways of the global aluminium cycle  

NASA Astrophysics Data System (ADS)

Climate change mitigation in the materials sector faces a twin challenge: satisfying rapidly rising global demand for materials while significantly curbing greenhouse-gas emissions. Process efficiency improvement and recycling can contribute to reducing emissions per material output; however, long-term material demand and scrap availability for recycling depend fundamentally on the dynamics of societies' stocks of products in use, an issue that has been largely neglected in climate science. Here, we show that aluminium in-use stock patterns set essential boundary conditions for future emission pathways, which has significant implications for mitigation priority setting. If developing countries follow industrialized countries in their aluminium stock patterns, a 50% emission reduction by 2050 below 2000 levels cannot be reached even under very optimistic recycling and technology assumptions. The target can be reached only if future global per-capita aluminium stocks saturate at a level much lower than that in present major industrialized countries. As long as global in-use stocks are growing rapidly, radical new technologies in primary production (for example, inert anode and carbon capture and storage) have the greatest impact in emission reduction; however, their window of opportunity is closing once the stocks begin to saturate and the largest reduction potential shifts to post-consumer scrap recycling.

Liu, Gang; Bangs, Colton E.; Müller, Daniel B.

2013-04-01

276

Laser synthesis of aluminium nanoparticles in biocompatible polymer solutions  

NASA Astrophysics Data System (ADS)

Pulsed laser ablation of Aluminium (Al) in pure water rapidly forms a thin alumina (Al2O3) layer which drastically modifies surface plasmon resonance (SPR) absorption characteristics in deep-UV region. Initially, pure aluminium nanoparticles (NPs) are generated in water without any stabilizers or surfactants at low laser fluence which gradually transform to stable Al-Al2O3 core-shell nanostructure with increasing either residency time or fluence. The role of laser wavelength and fluence on the SPR properties and oxidation characteristics of Al NPs has been investigated in detail. We also present a one-step in situ synthesis of oxide-free stable Al NPs in biocompatible polymer solutions using laser ablation in liquid method. We have used nonionic polymers (PVP, PVA and PEG) and anionic surfactant (SDS) stabilizer to suppress the Al2O3 formation and studied the effect of polymer functional group, polymeric chain length, polymer concentration and anionic surfactant on the incipient embryonic aluminium particles and their sizes. The different functional groups of polymers resulted in different oxidation states of Al. PVP and PVA polymers resulted in pure Al NPs; however, PEG and SDS resulted in alumina-modified Al NPs. The Al nanoparticles capped with PVP, PVA, and PEG show a good correlation between nanoparticle stability and monomeric length of the polymer chain.

Singh, Rina; Soni, R. K.

2014-05-01

277

Aluminium localization in root tips of the aluminium-accumulating plant species buckwheat (Fagopyrum esculentum Moench).  

PubMed

Aluminium (Al) uptake and transport in the root tip of buckwheat is not yet completely understood. For localization of Al in root tips, fluorescent dyes and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) were compared. The staining of Al with morin is an appropriate means to study qualitatively the radial distribution along the root tip axis of Al which is complexed by oxalate and citrate in buckwheat roots. The results compare well with the distribution of total Al determined by LA-ICP-MS which could be reliably calibrated to compare with Al contents by conventional total Al determination using graphite furnace atomic absorption spectrometry. The Al localization in root cross-sections along the root tip showed that in buckwheat Al is highly mobile in the radial direction. The root apex predominantly accumulated Al in the cortex. The subapical root section showed a homogenous Al distribution across the whole section. In the following root section Al was located particularly in the pericycle and the xylem parenchyma cells. With further increasing distance from the root apex Al could be detected only in individual xylem vessels. The results support the view that the 10 mm apical root tip is the main site of Al uptake into the symplast of the cortex, while the subapical 10-20 mm zone is the main site of xylem loading through the pericycle and xylem parenchyma cells. Progress in the better molecular understanding of Al transport in buckwheat will depend on the consideration of the tissue specificity of Al transport and complexation. PMID:21831842

Klug, Benjamin; Specht, André; Horst, Walter J

2011-11-01

278

Improving the wettability of 2024 aluminium alloy by means of cold plasma treatment  

NASA Astrophysics Data System (ADS)

Aluminium alloys are heavily used to manufacture structural parts in the aeronautic industry because of its lightness and its corrosion resistance. These alloys are successfully used in other industrial fields too, such as railway, automotive and naval industries. The need to contrast the severe use conditions and the heavy stresses developing in aeronautic field implies to protect the surfaces of the structures in aluminium alloy by any deterioration. To preserve by deterioration, it is necessary to make aluminium more suitable to be coated by protective paint. In the aeronautic industry, a complex and critical process is used in order to enhance both wettability and adhesive properties of aluminium alloy surfaces. Cold plasma treatment represents an efficient, clean and economic alternative to activate aluminium surfaces. The present work deals with air cold plasma treatment of 2024 aluminium alloy surfaces. The influence of dc electrical discharge cold plasma parameters on wettability of 2024 aluminium alloy surfaces has been studied. A set of process variables (voltage, time and air flow rate) has been identified and used to conduct some experimental tests on the basis of design of experiment (DOE) techniques. The experimental results show that the proposed plasma process may considerably increase aluminium alloy wettability. These results represent the first step in trying to optimise the aluminium adhesion by means of this non-conventional manufacturing process.

Polini, W.; Sorrentino, L.

2003-05-01

279

Light weight cellular structures based on aluminium  

SciTech Connect

An interesting form of lightweight material which has emerged in the past 2 decades is metallic foam. This paper deals with the basic concepts of making metallic foams and a detailed study of foams produced from Al-SiC. In addition, some aspects of cellular solids based on honeycomb structures are outlined including the concept of producing both two-phase foams and foams with composite walls.

Prakash, O. [Indian Inst. of Tech., Kanpur (India); Embury, J.D.; Sinclair, C. [McMaster Univ., Hamilton, ON (Canada); Sang, H. [Queen`s Univ., Kingston, ON (Canada); Silvetti, P. [Cordoba Univ. Nacional (Argentina). Facultad de Ciencias Exactas, Fisicas y Naturales

1997-02-01

280

NOVEL TECHNIQUES TO PREVENT EDGE ISOLATION OF SILICON SOLAR CELLS BY AVOIDING LEAK AGE CURRENTS BETWEEN THE EMITTER AND THE ALUMINIUM REAR CONTACT  

Microsoft Academic Search

Whenever the base contacting is effected by overcompensating the rear side electrically active emitter, short-circuits occur between the emitter and the alloyed aluminium rear contact. Without additional costly processing steps for the avoidance of excessive leakage currents this transition is non-rectifying. The development of novel cell designs like POWER (POlycrystalline Wafer Engineering Result) or EWT (Emitter Wrap-Through) solar cells with

K. Faika; R. Kühn; P. Fath; E. Bucher

281

The Potential of Aluminium Metal Powder as a Fuel for Space Propulsion Systems  

NASA Astrophysics Data System (ADS)

Metal powder propulsion systems have been addressed intermittently since the Second World War, initially in the field of underwater propulsion where research in the application of propelling torpedoes continues until this day. During the post war era, researchers attempted to utilise metal powders as a fuel for ram jet applications in missiles. The 1960's and 1970's saw additional interest in the use of `pure powder' propellants, i.e. fluidised metal fuel and oxidiser, both in solid particulate form. Again the application was for employment in space-constrained missiles where the idea was to maximise the performance of high energy density powder propellants in order to enhance the missile's flight duration. Metal powder as possible fuel was investigated for in-situ resource utilisation propulsion systems post-1980's where the emphasis was on the use of gaseous oxygen or liquid oxygen combined with aluminium metal powder for use as a ``lunar soil propellant'' or carbon dioxide and magnesium metal powder as a ``Martian propellant''.Albeit aluminium metal powder propellants are lower in performance than cryogenic and Earth storable propellants, the former does have an advantage inasmuch that the propulsion system is generic, i.e. it can be powered with chemicals mined and processed on Earth, the Moon and Mars. Thus, due to the potential refuelling capability, the lower performing aluminium metal powder propellant would effectively possess a much higher change in velocity (V) for multiple missions than the cryogenic or Earth storable propellant which is only suitable for one planet or one mission scenario, respectively.One of the principal limitations of long duration human spaceflight beyond cis-lunar orbit is the lack of refuelling capabilities on distant planets resulting in the reliance on con- ventional non-cryogenic, propellants produced on Earth. If one could develop a reliable propulsion system operating on pro- pellants derived entirely of ingredients found on nearby plan- etary bodies, then not only could mission duration be extended, larger amounts of payload could be ferried to and from the destination and eventually the cost of transporting propellant ingredients from Earth could be reduced, if not eliminated.

Ismail, A. M.; Osborne, B.; Welch, C. S.

282

Role of particle size of alumina on the formation of aluminium titanate as well as on sintering and microstructure development in sol–gel alumina–aluminium titanate composites  

Microsoft Academic Search

With a view to develop low temperature fine grained alumina–aluminium titanate composite, influence of alumina particle size on the temperature of formation of the aluminium titanate, sintering behaviour and microstructure development of alumina–aluminium titanate composite prepared through a sol–gel core shell approach is reported. The alumina matrix composite containing 20wt% aluminium titanate has been prepared from alumina powders having different

M. Jayasankar; K. P. Hima; S. Ananthakumar; P. Mukundan; P. Krishna Pillai; K. G. K. Warrier

2010-01-01

283

Integration of Eastern Europe and Russia in the World Market: Consequences for the Aluminium Production in Norway.  

National Technical Information Service (NTIS)

This report analyzes the consequences for the aluminium production in Norway from the reforms in the former centrally planned economics. The report is organised in the following way. Chapter 2 presents the latest developments in the world aluminium market...

M. D. Riiser

1995-01-01

284

Self-aligned gate dielectric in carbon nanotube field-effect transistors by anodic oxidation of aluminium  

Microsoft Academic Search

We demonstrate a process of fabricating carbon nanotube field-effect transistors with self-aligned gate insulators by anodic oxidation of aluminium. We use rapid thermal annealed multi-walled carbon nanotubes (CNTs) as the active material overlaid across an aluminium gate. The porous nanotube bundles allowed moisture from the air to penetrate, and oxidise the aluminium by anodic oxidation to construct a self-assembled aluminium

Jeff T. H. Tsai; Wei-Syun Wang; Szu-Hung Chen; Chia-Liang Sun

2011-01-01

285

Strategies to reduce the environmental impact of an aluminium pressure die casting plant: A scenario analysis  

Microsoft Academic Search

This study explores a model (MIKADO) to analyse scenarios for the reduction of the environmental impact of an aluminium die casting plant. Our model calculates the potential to reduce emissions, and the costs associated with implementation of reduction options. In an earlier paper [Neto, B., Kroeze, C., Hordijk, L., Costa, C., 2008. Modelling the environmental impact of an aluminium pressure

Belmira Neto; Carolien Kroeze; Leen Hordijk; Carlos Costa; Tinus Pulles

2009-01-01

286

Experimental determination of heat transfer coefficients during squeeze casting of aluminium  

Microsoft Academic Search

Heat transfer coefficients during squeeze cast of commercial aluminium were determined, by using the solidification temperature versus time curves obtained for varying applied pressures during squeeze casting process. The steel mould\\/cast aluminium metal interface temperatures versus times curve obtained through polynomial curves fitting and extrapolation was compared with the numerically obtained temperatures versus times curve. Interfacial heat transfer coefficients were

J. O. Aweda; M. B. Adeyemi

2009-01-01

287

Cyclic shear tests on Aluminium 3004 and 5182 alloys: macroscopic behaviour and substructural development  

Microsoft Academic Search

Cyclic shear tests with various constant strain amplitudes have been carried out to characterize the microstructural development under cyclic straining of aluminium-3004 and aluminium-5182 alloys. Substructural instabilities that occur inside the microstructure, their morphologies and crystallographies are reported. The hypothetical influence of these inhomogeneities on the observed macroscopic behaviour is discussed.

G. F. Dirras

1997-01-01

288

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

Microsoft Academic Search

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

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

2007-01-01

289

Temperature control in laser brazing of a steel\\/aluminium assembly using thermographic measurements  

Microsoft Academic Search

One way of making car bodies lighter is to introduce some aluminium parts in place of steel. Steel and aluminium can be joined by laser braze welding. As in other types of thermal joining, inter-metallic phases may weaken the joint. In laser braze welding, these appear as a thin layer of brittle compounds at the steel\\/seam interface. Their formation is

Alexandre Mathieu; Simone Matteï; Alexis Deschamps; Bruno Martin; Dominique Grevey

2006-01-01

290

STRENGTH PROPERTIES OF BIMETALLIC STEEL-ALUMINIUM INSERTS WITH CORRUGATED AND FLAT CONTACT SURFACE  

Microsoft Academic Search

INTRODUCTON Bimetallic steel-aluminium inserts are widely used since 1960s in cell's anode holders for joining aluminium bar and steel rod. Cell's operating conditions specify a number of requirements to operating parameters of inserts: 1. Since general voltage drop of the cell is rather small, about 4.5 V, increase of efficiency requires minimization of loss in the insert - no more

A. Z. Bogunov; A. A. Kuzovnikov; D. V. Kiselyov

2009-01-01

291

Interaction of 18Cr10Ni stainless steel with liquid aluminium  

Microsoft Academic Search

The dissolution of an 18Cr-10Ni stainless steel in liquid aluminium at 700 to 850 ° C was found by the rotating disc technique to be non-selective and diffusion controlled. Experimentally determined values of the parameters characterizing the dissolution run are presented. In the case of saturated aluminium melts two intermetallic layers were found to form between the steel and the

V. I. Dybkov

1990-01-01

292

Laser brazing of a steel\\/aluminium assembly with hot filler wire (88% Al, 12% Si)  

Microsoft Academic Search

The main problem in joining steel to aluminium by a thermal process (e.g. TIG, MIG) is the formation of brittle intermetallic phases, that causes the mechanical performance of the assembly to be poor. A laser beam, however, can localize the fusion and inhibit the formation of these phases. This article presents a feasibility study for steel\\/aluminium assemblies with filler wire

Alexandre Mathieu; Sébastien Pontevicci; Jean-claude Viala; Eugen Cicala; Simone Matteï; Dominique Grevey

2006-01-01

293

Aluminium based adjuvants and their effects on mitochondria and lysosomes of phagocytosing cells.  

PubMed

Aluminium oxyhydroxide, Al(OH)3 is one of few compounds approved as an adjuvant in human vaccines. However, the mechanism behind its immune stimulating properties is still poorly understood. In vitro co-culture of an aluminium adjuvant and the human monocytic cell line THP-1 resulted in reduced cell proliferation. Inhibition occurred at concentrations of adjuvant several times lower than would be found at the injection site using a vaccine formulation containing an aluminium adjuvant. Based on evaluation of the mitochondrial membrane potential, THP-1 cells showed no mitochondrial rupture after co-culture with the aluminium adjuvant, instead an increase in mitochondrial activity was seen. The THP-1 cells are phagocytosing cells and after co-culture with the aluminium adjuvant the phagosomal pathway was obstructed. Primary or early phagosomes mature into phagolysosomes with an internal pH of 4.5 - 5 and carry a wide variety of hydrolysing enzymes. Co-culture with the aluminium adjuvant yielded a reduced level of acidic vesicles and cathepsin L activity, a proteolytic enzyme of the phagolysosomes, was almost completely inhibited. THP-1 cells are an appropriate in vitro model in order to investigate the mechanism behind the induction of a phagocytosing antigen presenting cell into an inflammatory cell by aluminium adjuvants. Much information will be gained by investigating the phagosomal pathway and what occurs inside the phagosomes and to elucidate the ultimate fate of phagocytosed aluminium particles. PMID:23992993

Ohlsson, Lars; Exley, Christopher; Darabi, Anna; Sandén, Emma; Siesjö, Peter; Eriksson, Håkan

2013-11-01

294

Some Physical and Mechanical Properties of Glass-Aluminium Metal Composites.  

National Technical Information Service (NTIS)

An attempt was made to study some of the factors affecting certain properties of lead borate glass-aluminium metal composites. Lead borate glass was chosen because its softening point is between 500 and 600C which is similar to that of the aluminium metal...

A. Bishay J. Zahar M. M. Farag

1972-01-01

295

Modelling the environmental degradation of adhesively bonded aluminium and composite joints using a CZM approach  

Microsoft Academic Search

The long-term durability of adhesively bonded aluminium, composite and dissimilar substrate joints exposed to humid environments has been investigated. Failure of the joints was modelled with a cohesive zone model (CZM) approach where the governing parameters were determined from fracture mechanics test specimens saturated in a range of humid environments. The reduction in residual strength of an aluminium single lap

C. D. M. Liljedahl; A. D. Crocombe; M. A. Wahab; I. A. Ashcroft

2007-01-01

296

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

Microsoft Academic Search

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

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

2010-01-01

297

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

Microsoft Academic Search

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

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

2006-01-01

298

An experimental study on joining of severe plastic deformed aluminium materials with friction welding method  

Microsoft Academic Search

In this study, 5083 aluminium alloys, which were exposed to severe plastic deformation, were joined with friction welding method and the variation in mechanical properties of the joints was experimentally investigated. Severe plastic deformation methods can be classified as equal channel angular pressing (ECAP) (in other words, equal cross section lateral extrusion – ECSLE) and cyclic extrusion-compression. Aluminium alloy as

Mumin Sahin; H. Erol Akata; Kaan Ozel

2008-01-01

299

Process parameters optimization for friction stir welding of RDE40 aluminium alloy using Taguchi technique  

Microsoft Academic Search

Taguchi approach was applied to determine the most influential control factors which will yield better tensile strength of the joints of friction stir welded RDE-40 aluminium alloy. In order to evaluate the effect of process parameters such as tool rotational speed, traverse speed and axial force on tensile strength of friction stir welded RDE-40 aluminium alloy, Taguchi parametric design and

A. K. LAKSHMINARAYANAN; V. BALASUBRAMANIAN

2008-01-01

300

Tensile behavior of dissimilar friction stir welded joints of aluminium alloys  

Microsoft Academic Search

The heat treatable aluminium alloy AA2024 is used extensively in the aircraft industry because of its high strength to weight ratio and good ductility. The non-heat treatable aluminium alloy AA5083 possesses medium strength and high ductility and used typically in structural applications, marine, and automotive industries. When compared to fusion welding processes, friction stir welding (FSW) process is an emerging

N. Shanmuga Sundaram; N. Murugan

2010-01-01

301

Precipitating sandy aluminium hydroxide from sodium aluminate solution by the neutralization of sodium bicarbonate  

Microsoft Academic Search

In the sinter process for alumina production, it is still difficult to produce sandy aluminium hydroxide by the carbonation of sodium aluminate solution. Therefore, a precisely controllable and feasible process for the precipitation of sandy aluminium hydroxide from the supersaturated sodium aluminate solution neutralized by sodium bicarbonate aqueous solution is proposed for the first time, in which the neutralization reagent

Yan Li; Yifei Zhang; Chao Yang; Yi Zhang

2009-01-01

302

Aluminium Foil as a Food Packaging Material in Comparison with Other Materials  

Microsoft Academic Search

Aluminium foil is an important material in laminates and has wide application in food packaging. Its barrier function against the migration of moisture, oxygen and other gases, and volatile aroma, as well as against the impact of light is generally higher than any plastic laminate material. Therefore, aluminium foil is used in the laminates when insufficient barrier properties are the

Manuela Lamberti; Felix Escher

2007-01-01

303

Characterisation of intermetallic growth in copper and gold ball bonds on aluminium metallization  

Microsoft Academic Search

While the characterisation of intermetallic coverage and intermetallic phase (IP) growth in gold ball bonding on aluminium is quite well understood, there is relatively little literature concerning the morphology and growth of IP's between Cu balls bonded on aluminium pad metallisation. The difference between Cu-Al IP growth compared with the well known Au-Al IP's has been studied mainly of larger

F. W. Wulff; C. D. Breach; D. Stephan; Saraswati; K. J. Dittmer

2004-01-01

304

Enhancement of properties of red iron oxide – aluminium oxide solid solutions anticorrosive pigments  

Microsoft Academic Search

Purpose – Several solid solution combinations of aluminium oxide and iron oxide, for the preparation of a new pigment, were investigated to study the effect of aluminium oxide to iron oxide ratio on various properties of the resulting pigments. Design\\/methodology\\/approach – The conditions for the preparation of the pigments via solid solution interaction at 1,000°C had been estimated. Characterisation of

N. M. Ahmed; M. M. Selim

2005-01-01

305

Correlation between ultimate tensile strength and solidification microstructure for the sand cast A357 aluminium alloy  

Microsoft Academic Search

Many studies have demonstrated a relationship between secondary dendrite arm spacing (SDAS) and the mechanical behaviour of cast aluminium–silicon alloys, both for tensile and fatigue strength. SDAS is related to the solidification time and can be predicted, with a good approximation, by finite-element simulation. However, other microstructural features can affect the tensile behaviour of cast aluminium alloys such as size

L. Ceschini; Alessandro Morri; Andrea Morri; A. Gamberini; S. Messieri

2009-01-01

306

Microstructural studies of aluminium-silicon alloy reinforced with alumina fibres  

Microsoft Academic Search

The microstructure of an alumina fibre reinforced Al-7wt% Si alloy has been investigated. It was shown that the Al-Si eutectic structure which characterized this alloy was markedly changed by the presence of the fibres, with coarsening of silicon particles and a reduction in primary aluminium grain size. The coarse silicon particles exhibited twinning but no orientation relationship with the aluminium.

Ming Yang; V. D. Scott

1991-01-01

307

Interfacial reaction and strength of SiC fibres coated with aluminium alloys  

Microsoft Academic Search

Silicon carbide fibres (Nicalon) were coated with pure aluminium and aluminium alloys containing silicon. The coated fibres were annealed to produce an interfacial reaction zone between the coated layer and the fibre. The effect of this reaction zone on the tensile strength of the fibre was investigated. During the early stages of growth the reaction zone of the fibre is

H. Liu; U. Madaleno; T. Shinoda; Y. Mishima; T. Suzuki

1990-01-01

308

Compressibility and structure factors at zero wavevector of liquid aluminium-silicon alloys  

Microsoft Academic Search

A precise 'pulse-echo method' is used to measure the sound velocity in liquid aluminium and aluminium-silicon alloys from the melting point up to 1000 degrees C. The adiabatic compressibility and static structure factors are evaluated. It is found that the compressibility and structure factors display anomalous variations around the eutectic composition.

N. M. Keita; S. Steinemann

1978-01-01

309

On the alloying of aluminium to silicon in the fabrication of integrated circuits  

Microsoft Academic Search

The alloying of aluminium to silicon during the fabrication of silicon integrated circuits, as is well known, often results in 'spearing' at the contact windows and that this represents a possible failure mechanism. The morphology and kinetics of the spearing process are discussed, in particular, evidence for the existence of a liquid phase at alloying temperatures below the silicon-aluminium eutectic

L. A. Berthoud

1977-01-01

310

MODELLING OF THERMAL PROCESSES IN A DISSYMMETRICAL WELDED CAST ALUMINIUM DESIGNS  

Microsoft Academic Search

Number of constructions, produced from eutectic silumins are continually increasing, therefore problem of their welding became very actual. Eutectic aluminium - silicon alloys are sensitive to changes of a welding thermal cycle. These cast aluminium alloys constructions after welding have large residual stresses, and mechanical properties of welded joint deteriorate. It is difficult to define welding regime in case of

N. Višniakov; D. Š?ekaturovien?; O. ?ernaš?jus

311

Direct complexometric determination of magnesium in the presence of uranium, iron and aluminium.  

PubMed

Conditions for the direct complexometric determination of magnesium in the presence of uranium, iron and aluminium are described. The method is based on the masking of uranium by hydroxylamine, and of iron and aluminium by triethanolamine. Methylthymol Blue is used as indicator for the EDTA titration of magnesium at pH 10. PMID:18960663

Mareska, V

1969-11-01

312

The electrochemical deposition of polyaniline at pure aluminium: electrochemical activity and corrosion protection properties  

Microsoft Academic Search

Polyaniline films were electrodeposited at pure aluminium from a tosylic acid solution containing aniline. These polymer films exhibited similar characteristics as pure polyaniline electrosynthesized at an inert platinum electrode, when removed from their respective substrates and dissolved in NMP. Both polymers had similar molecular weights and similar UV-visible absorption spectra. However, the aluminium substrate had a considerable effect on the

Kenneth G. Conroy; Carmel B. Breslin

2003-01-01

313

Interface reactions during preparation of aluminium-matrix composites by the sodium process  

Microsoft Academic Search

A process has been developed in which aluminium matrix composites, reinforced by either graphite or polycrystalline alumina (FP) fibres, are prepared by immersing the fibres sequentially in molten baths of sodium, tin, and aluminium. The experimental details of this process are presented, and the theory behind the process is explained. In essence, sodium wets the fibres, and is then reacted

D. M. Goddard

1978-01-01

314

Dynamic Deformation of Aluminium and Copper as a Thermally Activated Process.  

National Technical Information Service (NTIS)

The steady-state flow stress at high strain-rate and at elevated temperatures of commercial purity aluminium and copper was analysed using the theory of the thermally activated deformation of metals. The experimental activation energy for aluminium was de...

S. K. Samanta

1970-01-01

315

Corrosion of aluminium in the aqueous chemical environment of a loss-of-coolant accident at a nuclear power plant  

Microsoft Academic Search

Aluminium corrosion is a significant concern in the aqueous chemical environment of the reactor containment building following a hypothetical loss-of-coolant accident (LOCA) at a nuclear power plant. Aluminium corrosion may lead to the formation of precipitates that can, in combination with insulation debris, block the recirculation sump screens. This study investigated aluminium corrosion experimentally at both bench and pilot scale

Dong Chen; Kerry J. Howe; Jack Dallman; Bruce C. Letellier

2008-01-01

316

INVESTIGATION OF THE ALLOYING PROCESS OF SCREEN PRINTED ALUMINIUM PASTES FOR THE BSF FORMATION ON SILICON SOLAR CELLS  

Microsoft Academic Search

This paper is intended to give insights into the formation process of aluminium alloyed back surface fields (BSF) and rear contacts made by firing screen printed aluminium pastes. It is shown that a sufficient oxygen supply from the gas ambient is important to thicken and strengthen the oxide shells enclosing the liquid aluminium and silicon during firing. The alloying action

F. Huster

317

Herstellung und Charakterisierung supraleitender Aluminium-Filme als Phononenkollektoren fuer Kryodetektoren. (Preparation and characterization of superconducting aluminium thin films as phonon collectors for cryodetectors).  

National Technical Information Service (NTIS)

The goal was to prepare high-purity, superconducting aluminium thin films and establish their characteristic properties with respect to the intended use. The work accomplished to this end included operation of a UHV vapor deposition device; system design ...

M. Loidl

1995-01-01

318

Le nitrure d'aluminium : de la poudre au substrat  

NASA Astrophysics Data System (ADS)

The aluminium nitride is a material which should replace alumina or beryllia as substrate for power electronic applications. The powder, prepared by carbothermal nitridation, is dispersed in a butanone-2-ethanol azeotrop solvent with a phosphate ester. Electrical conductivity, sedimentation, viscosity have been used to determine which phenomena take place in the defloculation of the suspension. The stability of AlN suspensions is due mainly to an electrostatic mechanism, with a steric contribution. The aluminium nitride tape-casting slip has been sintered at 1 850°C in a nitrogen atmosphere. Removing of the binder and plasticizer can be performed in the same oven at 650°C, due to their nature and low concentration. The thermal conductivity of the substrates has been measured and is in the 160 to 200W/m.K range. Le nitrure d'aluminium est le matériau appelé à remplacer l'alumine ou l'oxyde de béryllium en tant que substrat dans les circuits de puissance en microélectronique. La poudre utilisée préparée par carbonitruration a été mise en suspension dans le milieu azéotropique butanone-2-éthanol en présence d'un ester phosphorique. Conductivité, sédimentation, viscosité ont permis d'appréhender les phénomènes qui permettent de défloculer la suspension. La stabilité est assurée par un mécanisme électrostatique ayant une contribution stérique. Le nitrure est coulé en bande puis fritté à 1?850°C sous azote. La qualité et la faible teneur du liant permettent de l'éliminer dans le même four à 650°C. Les conductivités thermiques des substrats sont comprises entre 160 et 200W/m.K.

Jarrige, J.; Mexmain, J.; Oumaloul, M.; Bachelard, R.; Disson, J. P.

1993-04-01

319

The chemical transformation of copper in aluminium oxide during heating  

NASA Astrophysics Data System (ADS)

Thermal treatment has recently been emerging as a promising environmental technology to stabilize heavy metal-containing industrial sludge. This study used x-ray absorption spectroscopy (XAS) to identify the species of copper contaminant contained in aluminium oxide that is one of the main compositions of sludge and soil. Results indicate that the originally loaded copper nitrate was transformed into Cu(OH)2 after its dissolution in the aluminium oxide slurry. Extended x-ray absorption fine structure (EXAFS) fitting indicates that the main copper species in the 105 °C dried Cu(NO3)2-loaded aluminium oxide is Cu(OH)2 which accounts for ca. 75% of the loaded copper. After thermal treatment at 500 °C for 1 h, both x-ray absorption near-edge structure (XANES) and EXAFS fitting results show that CuO became the prevailing copper species (about 85%); the rest of the copper consisted of {\\sim }15{%} Cu(OH)2 and a negligible amount of Cu(NO3)2. It was found that most Cu(OH)2 and Cu(NO3)2 decomposed into CuO at 500 °C. Further increase of the heating temperature from 500 to 900 °C resulted in more decomposition of Cu(OH)2 and Cu(NO3)2; therefore CuO remained as the main copper species. However, it was suggested that about 15% of the loaded copper formed CuAl2O4 through the chemical reaction between CuO and Al2O3 at 900 °C.

Wei, Yu-Ling; Wang, Hsi-Chih; Yang, Yaw-Wen; Lee, Jyh-Fu

2004-08-01

320

Are aluminium potroom workers at increased risk of neurological disorders?  

PubMed Central

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.

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

1997-01-01

321

Hexaaqua-aluminium(III) tris-(methane-sulfonate).  

PubMed

The title compound, [Al(H(2)O)(6)](CH(3)SO(3))(3) (common name: aluminium methane-sulfonate hexa-hydrate), was crystallized from an aqueous solution prepared by the precipitation reaction of aluminium sulfate and barium methane-sulfonate. Its crystal structure is the first of the boron group methane-sulfonates to be determined. The characteristic building block is a centrosymmetric unit containing two hexa-aqua-aluminium cations that are connected to each other by two O atoms of the -SO(3) groups in an O-H?O?H-O sequence. Further O-H?O hydrogen bonding links these blocks in orthogonal directions - along [010] forming a double chain array, along [10-1] forming a layered arrangement of parallel chains and along [101] forming a three-dimensional network. As indicated by the O?O distances of 2.600?(3)-2.715?(3)?Å, the hydrogen bonds are from medium-strong to strong. A further structural feature is the arrangement of two and four methyl groups, respectively, establishing 'hydro-phobic islands' of different size, all positioned in a layer-like region perpendicular to [101]. The only other building block within this region is one of the -SO(3) groups giving a local connection between the hydro-philic structural regions on both sides of the 'hydro-phobic' one. Thermal analysis indicates that a stepwise dehydration process starts at about 413?K and proceeds via the respective penta- and dihydrate until the compound completely decomposes at about 688?K. PMID:22904782

Trella, Thomas; Frank, Walter

2012-08-01

322

Investigation of the optical properties of hollow aluminium 'nano-caps'  

NASA Astrophysics Data System (ADS)

A colloidal suspension of hollow aluminium, cap-shaped nanoparticles ('nano-caps') can be conveniently produced by evaporation of aluminium onto a spin-coated layer of polystyrene nanoparticles (PSNPs), followed by sonication and dissolution of the polymer template. Although ordinary spherical aluminium nanoparticles have a plasmon resonance in the ultra-violet, the 'nano-caps' show plasmon absorption between 700 and 1200 nm due to their geometry. The position of their extinction peaks can be tuned by varying the thickness of the aluminium and the shape of the nano-cap. The optical properties of these shapes were modelled using the discrete dipole approximation method, which confirmed that the 'caps' have very significantly red-shifted absorbance and scattering compared to spheres. This finding suggests that aluminium nano-caps might compete with gold and silver nanoparticles in applications requiring absorption in the near infrared.

Liu, J.; Cankurtaran, B.; McCredie, G.; Ford, M. J.; Wieczorek, L.; Cortie, M. B.

2005-12-01

323

Aluminium in Cars â Unlocking the Light-Weighting Potential  

NSDL National Science Digital Library

In this brochure, the European Aluminium Association (EAA) evaluates the need for vehicle lightweighting to reduce CO2 emissions. Since the 70âs aluminum has been used for some car components (radiators, cylinder heads, and bumper beams), but now has grown to the average amount of 140 kg per car produced in Europe. Aluminum castings, extrusions, forgings and sheets can now be found nearly everywhere, including in car bodies, closures, chassis, suspensions and wheels. This resource explains why, now more than ever, reducing vehicle mass is necessary and how aluminum can be used to further improve the sustainability and the safety of future generations of cars.

Association, European A.

324

Effects of Combined Exposure to Aluminium and Ethanol on Aluminium Body Burden and some Neuronal, Hepatic and Haematopoietic Biochemical Variables in the Rat  

Microsoft Academic Search

The effects of the daily administration of aluminium (25 mg kg-1, orally), ethanol (10% v\\/v, in drinking water) or both to adult rats, for 6 weeks, on the amount of aluminium present in the tissues and the functioning of brain biogenic amines, hepatic and serum transaminases and some haematopoietic variables were investigated.Ethanol alone was seen to inhibit the activity of

S. J. S. Flora; Mamta Dhawan; S. K. Tandon

1991-01-01

325

Comparative study of aluminium-doped zinc oxide and ruthenium–aluminium co-doped zinc oxide by magnetron co-sputtering  

Microsoft Academic Search

Highly oriented polycrystalline aluminium-doped (Al-doped) and ruthenium–aluminium (Ru–Al) co-doped zinc oxide are prepared on borosilicate glass and polycarbonate (PC) substrates by co-sputtering at room temperature. To investigate the effect of Ru doping, co-sputtering is achieved by varying the sputtering power of Ru target while keeping the sputtering target power of Al-doped zinc oxide unchanged. Atomic force microscopy (AFM) data shows

L. M. Wong; S. J. Wang; W. K. Chim

2010-01-01

326

Effect of the aluminium concentration on the resonant tunnelling time and the laser wavelength of random trimer barrier AlxGa1-xAs superlattices  

NASA Astrophysics Data System (ADS)

In this study, we investigated numerically the effect of aluminium concentration on the resonant tunnelling time (RTT) and the laser wavelength of random trimer barrier AlxGa1-xAs superlattices (RTBSL). Such systems consist of two different structures randomly distributed along the growth direction, with the additional constraint that the barriers of one kind appear in triply. An explicit formula is given for evaluating the transmission coefficient of superlattices (SL’s) with intentional correlated disorder. The method is based on Airy function formalism and the transfer-matrix technique. We discuss the impact of the aluminium concentration associated to the structural profile of the SL’s on the RTT and the laser wavelengths.

Bendahma, F.; Bentata, S.; Djelti, R.; Aziz, Z.

2014-09-01

327

Surfacing weld metal properties of aluminium alloys with Al?Cu cored wire: Surfacing of aluminium alloys (3rd report)  

Microsoft Academic Search

This paper describes an investigation of the properties of surfacing weld metals produced by the MIG and TIG processes using newly developed 1.2 mm dia. Al?Cu seamless cored electrode wires. Three types of Al?Cu cored wires with Cu contents of 40%, 45%, and 70% were tested on type A1050P (Al), A5083P (Mn?Mg?Al), A7075P (Cu?Mg?Zn?Al), and AC4B (Si?Cu?Zn, cast) aluminium alloy

Y. Kanbe; Y. Nakada; S. Kurihana; H. Koike; T. Miyake

1994-01-01

328

Aluminium-induced nanocrystalline Ge formation at low temperatures.  

PubMed

The present work contributes to establishing the role of hydrogenation and of the substrates in the aluminium-induced crystallization process of amorphous germanium layers. For such a purpose, four series of a-Ge(Al) samples, deposited under identical nominal conditions, were studied: hydrogenated samples, H-free samples, and samples deposited on crystalline silicon and on glass substrates, respectively. On purpose, the impurity concentration was kept at a doping level (10??<[Al/Ge]<2 × 10?³). Furthermore, the films were submitted to isochronal cumulative thermal annealing in the 200-550?°C range. Raman scattering spectroscopy was used to characterize the crystallization process. The role of Al impurity as a precursor seed for the crystallization of a-Ge:H has been clearly established, confirming that the metal-induced crystallization (MIC) phenomenon occurs at an atomic level. Moreover, it has been found that hydrogenation and the periodic nature of the substrate play a fundamental role in the appearance of crystal seeds at low temperatures. The evolution of crystallization with annealing temperature and the analysis of the distribution of crystallite sizes indicate that the formation of crystal seeds occurs at the amorphous film-substrate interface. The importance of fourfold-coordinated aluminium as the embryo of nanocrystal formation is discussed. PMID:22251593

Muniz, L R; Ribeiro, C T M; Zanatta, A R; Chambouleyron, I

2007-02-21

329

Perforation of aluminium foam core sandwich panels under impact loading  

NASA Astrophysics Data System (ADS)

This paper reports an original inverse perforation tests on foam core sandwich panels under impact loading. The key point is the use of an instrumented Hopkinson pressure bar as a perforator and at the same time a measuring device. It aims at a high quality piercing force record during the whole perforation process, which is a lack of common free-flying projectile - target testing schemes. This new testing arrangement allows for the measurement of piercing force-displacement curves under quasi-static and impact loadings of sandwich samples, which is made of 40?mm AlSi7Mg0.5 Cymat foam cores and 0.8?mm thick 2024 T3 aluminium sheet as top and bottom skins. Compared with quasi-static top skin peak loads (the maximal load before the perforation of top skins) obtained under same geometric and clamping conditions and even in the case that the used foam core (Cymat) and aluminium skin sheet are known and have been confirmed rate insensitive, a significant enhancement under impact loading (25%) of the top skin peak load is found.

Elnasri, I.; Zhao, H.; Girard, Y.

2006-08-01

330

Cancellous bone homograft storage with aluminium-polyethylene bags.  

PubMed

In order to transport and cryopreserve human tissues, it is essential to have an easy-to-use recipient where tissues can be kept in sterile conditions. Here we show the results obtained by using Macopharma's tissue freezing bags, an aluminium-polyethylene multilayer bag, in our tissue bank of the Centro Comunitario de Sangre y Tejidos de Asturias. Five hundred and twenty-seven cancellous bone homografts were obtained from hospitals located 120 km around our Bank. The homografts were submitted to bacteriological controls and sent to our bank in these bags. They were stored at -70 degrees C and sent in dry ice to about 50 hospitals, where the tissue was bacteriologically controlled and grafted. Furthermore, the behaviour of these bags at -140 degrees C (vapour nitrogen) or -196 degrees C (liquid nitrogen) was tested. Our results indicate that Macopharma aluminium-polyethylene bags are suitable for the transporting and cryopreserving of cancellous bone homografts. These bags could also be used for keeping tissues in nitrogen containers. PMID:16933042

Meana, A; Martinez, R; Cañal, P; Arriaga, M J; Román, F San; Llames, S; Orós, C; Moreno, A; Fernandez, C

2006-01-01

331

Experimental study of aluminium honeycomb behaviour under dynamic multiaxial loading  

NASA Astrophysics Data System (ADS)

Split Hopkinson Pressure Bar system (SHPB) with large-diameter and Nylon bars introducing a shear-compression loading device is used in order to investigate the dynamic behaviour of aluminium honeycomb under multiaxial loadings conditions. All shear-compression configurations including the loading angle variation from 0? to 60? are performed with an impact velocity of about 15m/s. The adapted SHPB system with the device are validated numerically and a phenomenon of separation between the input bar and the input beveled bar is observed. Numerical results suggest that this phenomenon provides a cutting of the reflected wave. An electro optical extensometer is employed in experiments. A good agreement between the numerical elastic waves and the experimental ones is obtained. Experimental results show a significant effect of the loading angle on the apparent stress-strain curves. The initial peak value and the plateau stress decrease with the increase of the loading angle. The combined shear-compression device with an enhancement at the alignment set-up provides efficient results for samples dynamically loaded. This device will be used to investigate the influence of the in-plane orientation angle on the deformation mechanisms and multiaxial behaviour of aluminium honeycomb under dynamic and quasi-static loading conditions.

Tounsi, R.; Zouari, B.; Chaari, F.; Haugou, G.; Markiewicz, E.; Dammak, F.

2012-08-01

332

Controlling interferometric properties of nanoporous anodic aluminium oxide  

PubMed Central

A study of reflective interference spectroscopy [RIfS] properties of nanoporous anodic aluminium oxide [AAO] with the aim to develop a reliable substrate for label-free optical biosensing is presented. The influence of structural parameters of AAO including pore diameters, inter-pore distance, pore length, and surface modification by deposition of Au, Ag, Cr, Pt, Ni, and TiO2 on the RIfS signal (Fabry-Perot fringe) was explored. AAO with controlled pore dimensions was prepared by electrochemical anodization of aluminium using 0.3 M oxalic acid at different voltages (30 to 70 V) and anodization times (10 to 60 min). Results show the strong influence of pore structures and surface modifications on the interference signal and indicate the importance of optimisation of AAO pore structures for RIfS sensing. The pore length/pore diameter aspect ratio of AAO was identified as a suitable parameter to tune interferometric properties of AAO. Finally, the application of AAO with optimised pore structures for sensing of a surface binding reaction of alkanethiols (mercaptoundecanoic acid) on gold surface is demonstrated.

2012-01-01

333

High-Rate Compaction of Aluminium Alloy Foams  

NASA Astrophysics Data System (ADS)

The response of aluminium foams to impact can be categorised by the impact velocity. Tests are reported ranging from quasi-static to impact velocities greater than the speed of sound in the foam. The techniques used ranging from drop-hammer and pneumatic launcher tests, to plate impact at velocities greater than 1000 m s-1. The quasi-static compression behaviour was elastic, perfectly-plastic, locking. For static and dynamic compression at low impact velocities, post-impact examination of partially crushed specimens showed that deformation was through the cumulative multiplication of crush bands. If the impact velocity is less than the velocity of sound, but above a certain critical impact velocity, the plastic compression occurs in a shock-like manner and the specimens deform by progressive cell crushing. At higher impact velocities the compaction front is not preceded by an elastic wave. 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 input as the input dataset to an Eulerian code. Hydrocode simulations were then carried out on real microstructure. These simulations provide insight to mechanisms associated with the localization of deformation.

Harrigan, J. J.; Millett, J. C. F.; Milne, A. M.

2005-07-01

334

High-Rate Compaction of Aluminium Alloy Foams  

NASA Astrophysics Data System (ADS)

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.

Harrigan, J. J.; Hung, Y.-C.; Tan, P. J.; Bourne, N. K.; Withers, P. J.; Reid, S. R.; Millett, J. C. F.; Milne, A. M.

2006-07-01

335

Catalytic spectrophotometric determination of trace aluminium with indigo carmine  

NASA Astrophysics Data System (ADS)

A new catalytic spectrophotometric method is described for the determination of trace amounts of Al(III). The methods based on catalytic action of Al(III) on the oxidation of indigo carmine (IC) by ammonium persulfate in hexamethylene tetramine-hydrochloric acid ((CH 2) 6N 4-HCl) buffer medium (pH 5.4) and in the presence of surfactant—TritonX-100. The effects of some factors on the reaction speed were investigated. Aluminium concentration is linear for 0-1.2 × 10 -7 g/ml in this method. The detection limit of the proposed method is 1.96 × 10 -8 g/ml. Most of the foreign ions except for Cu(II), Fe(III) do not interfere with the determination, and the interference of Cu(II) and Fe(III) in this method can be removed by extraction with sodium diethyldithiocarbamate-carbon tetrachloride (DDTC-CCl 4). This system is a quasi-zero-order reaction for Al(III), but it is a quasi-first-order reaction for IC. The apparent rate constant is 2.62 × 10 -5 s -1 and the apparent activation energy is 6.60 kJ/mol in the system. The proposed method was applied to the determination of trace aluminium(III) in real samples with satisfactory results.

Zheng, Huai-Li; Xiong, Wen-Qiang; Gong, Ying-Kun; Peng, De-Jun; Li, Ling-Chun

2007-04-01

336

High-Rate Compaction of Aluminium Alloy Foams  

SciTech Connect

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.

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

337

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

NASA Astrophysics Data System (ADS)

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.

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

2013-10-01

338

Asphalt enhancing additive  

US Patent & Trademark Office Database

An asphalt enhancing additive, an asphalt cement and an asphalt mixture containing the additive, wherein the additive causes the mixture to be more easily workable so that the asphalt mixture can be manufactured at a temperature lower than the conventional ones, wherein the additive comprises the mixture of an aminic compound, a lubricant and a flux.

2011-09-13

339

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

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

340

Aqueous aluminium eliminates Gyrodactylus salaris (Platyhelminthes, Monogenea) infections in Atlantic salmon.  

PubMed

This study focuses on the effect of acidic water and aqueous aluminium on the monogenean ectoparasite Gyrodactylus salaris, infecting Atlantic salmon (Salmo salar) parr. G. salaris-infected salmon were exposed to various combinations of acidity and aluminium concentrations. The most pronounced effect was the elimination of parasites after 4 days when 202 micrograms Al/l was added to the water. The effect of aluminium was concentration dependent, but was relatively independent of pH (5.2, 5.6 and 5.9). At the lowest pH of 5.0 the effect of aluminium was enhanced. Acidic aluminium-poor water had no or minor effects on the G. salaris infections except at pH 5.0 where all parasites were eliminated within 9 days. The G. salaris populations increased exponentially in untreated control water. The results show for the first time that aqueous aluminium can, to a limited extent, have a positive effect on fish health. This study emphasizes that basic knowledge about abiotic environmental factors is of importance in order to understand the population dynamics, range extension and dispersal of ectoparasites such as G. salaris. Finally, our results suggest that aluminium treatment could form an effective disinfection method against ectoparasites in hatcheries and laboratories, as well as complementing the controversial rotenone treatments used against natural populations of G. salaris. PMID:10446701

Soleng, A; Poléo, A B; Alstad, N E; Bakke, T A

1999-07-01

341

Aluminium adjuvants and adverse events in sub-cutaneous allergy immunotherapy.  

PubMed

Sub-cutaneous immunotherapy is an effective treatment for allergy. It works by helping to modify or re-balance an individual's immune response to allergens and its efficacy is greatly improved by the use of adjuvants, most commonly, aluminium hydroxide. Aluminium salts have been used in allergy therapy for many decades and are assumed to be safe with few established side-effects. This assumption belies their potency as adjuvants and their potential for biological reactivity both at injection sites and elsewhere in the body. There are very few data purporting to the safety of aluminium adjuvants in allergy immunotherapy and particularly so in relation to longer term health effects. There are, if only few, published reports of adverse events following allergy immunotherapy and aluminium adjuvants are the prime suspects in the majority of such incidents. Aluminium adjuvants are clearly capable of initiating unwanted side effects in recipients of immunotherapy and while there is as yet no evidence that such are commonplace it is complacent to consider aluminium salts as harmless constituents of allergy therapies. Future research should establish the safety of the use of aluminium adjuvants in sub-cutaneous allergy immunotherapy. PMID:24444186

Exley, Christopher

2014-01-01

342

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

PubMed Central

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.

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

1996-01-01

343

Laser welding of aluminium alloys 5083 and 6082 under conduction regime  

NASA Astrophysics Data System (ADS)

In this work, samples of aluminium alloys 5083-T0 and 6082-T6 have been welded under conduction regime, using a high power diode laser. The influence of experimental variables, as the laser power and the linear welding rate, on the sizes and properties of the butt weld beads has been studied. In addition to measure the depths and widths of the weld beads, their microstructure, microhardness profile and corrosion resistance have been analysed. The results obtained allow one to define the experimental conditions leading to good quality butt welds with higher penetration than those published in the recent literature under conduction regime. Maximum penetration values of 3 and 2.3 mm were obtained for 5083 and 6082, respectively. Additionally, a simple mathematical expression relating the weld depth ( d) with the laser power ( P) and the processing rate ( v) has been proposed: d=(P-bb)/(av)-(ba)/a, being a, a', b and b' constant values for each alloy and under the employed experimental conditions. The values of these coefficients have been estimated from the fitting to the experimental depth values of 5083 and 6082 butt welds generated under conduction regime.

Sánchez-Amaya, J. M.; Delgado, T.; González-Rovira, L.; Botana, F. J.

2009-09-01

344

Electrothermal atomic absorption spectrometry determination of aluminium in parenteral nutrition and its components.  

PubMed

Aluminium concentration in samples of total parenteral nutrition solutions and samples of their individual components were analysed to know the exposure to this element. The median aluminium content obtained for the total parenteral nutrition solutions was 105.7 microg/L; for their individual components, 10% calcium gluconate and 1M monopotasic phosphate were the most contaminated, as well as the 1M sodium bicarbonate. The great variability found in the aluminium content of solutions suggests that contamination occurs during the manufacturing process. PMID:18039492

Alvarez, Laura; Rebollido, Maira; Fernandez-Lorenzo, José Ramon; Cocho, José Angel; Fraga, José Maria

2007-01-01

345

[Study on fluorescent properties and application of the new reagent DCOBAQS with aluminium].  

PubMed

A new fluorometric method is reported for the determination of aluminium, based on the complex forming of 7-[(2,4-dicarboxymethyl-5-carboxybenezene)azo]-8-hydroxyquinoline-5-sulfonic (DCOBAQS) with aluminium. The complex was formed at pH 5.54 with lambda ex/lambda em = 510 nm/572 nm. A better line relationship curve was obtained over the range of 0-0.04 microgram.mL-1 Al(III), and the detection limit for Al(III) is 0.557 ng.mL-1. The method is applied to determination aluminium in tea with satisfactory results. PMID:12953588

Wu, F; Haung, J

2001-02-01

346

Influence of chemical bonding on X-ray spectra of different aluminium compounds  

NASA Astrophysics Data System (ADS)

Five minerals containing aluminium in different crystal configurations are studied. The different kinds of chemical bonding between aluminium and oxygen originate molecular orbitals with energy levels and transition probabilities varying from one compound to another. This effect appears as shifts and changes in relative intensities of K? emission lines and as modifications of the K? characteristic spectrum. In the present work, the aluminium K characteristic spectra obtained by means of an electron microprobe with a wavelength dispersive system are compared for topaz, albite, spodumene, biotite and corundum.

Bonetto, Rita; Trincavelli, Jorge; Vasconcellos, Marcos

2005-11-01

347

Nano-sized layered aluminium or zinc-manganese oxides as efficient water oxidizing catalysts.  

PubMed

Nano-sized layered aluminium or zinc-manganese oxides were synthesized and characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction spectrometry, dynamic light scattering and atomic absorption spectroscopy. These oxides showed efficient water oxidizing activity in the presence of cerium(IV) ammonium nitrate as a non-oxo transfer oxidant. Amounts of dissolved manganese, zinc or aluminium, and water oxidation activities of these oxides were reported and compared with other manganese oxides. A mechanism for oxygen evolution and possible roles for zinc or aluminium ions are also proposed. PMID:22565665

Najafpour, Mohammad Mahdi; Pashaei, Babak; Nayeri, Sara

2012-06-21

348

[Food additives and healthiness].  

PubMed

Additives are used for improving food structure or preventing its spoilage, for example. Many substances used as additives are also naturally present in food. The safety of additives is evaluated according to commonly agreed principles. If high concentrations of an additive cause adverse health effects for humans, a limit of acceptable daily intake (ADI) is set for it. An additive is a risk only when ADI is exceeded. The healthiness of food is measured on the basis of nutrient density and scientifically proven effects. PMID:24772784

Heinonen, Marina

2014-01-01

349

Polyimide processing additives  

NASA Technical Reports Server (NTRS)

A method has been found for enhancing the melt flow of thermoplastic polyimides during processing. A high molecular weight 422 copoly(amic acid) or copolyimide was fused with approximately 0.05 to 5 pct by weight of a low molecular weight amic acid or imide additive, and this melt was studied by capillary rheometry. Excellent flow and improved composite properties on graphite resulted from the addition of a PMDA-aniline additive to LARC-TPI. Solution viscosity studies imply that amic acid additives temporarily lower molecular weight and, hence, enlarge the processing window. Thus, compositions containing the additive have a lower melt viscosity for a longer time than those unmodified.

Pratt, J. R.; St. Clair, T. L.; Burks, H. D.; Stoakley, D. M.

1987-01-01

350

Materials Science Constraints on the Development of Aluminium Reduction Cells  

NASA Astrophysics Data System (ADS)

The Hall-Heroult process for the production of Aluminium metal is some 125 years old. The process is energy constrained by the need to shed around half of the (electrical) energy supplied to the cell as waste heat. The molten cryolite electrolyte is sufficiently aggressive that the only reliable method of protecting the side wall of the cell is to maintain a frozen layer of electrolyte at the hot face of the sidewall. Thus the lack of a cryolite resistant sidewall is but one of several materials science constraints which still limit the energy efficiency of the process. An inert anode and non-consumable cathode are also significant challenges which limit cell life and energy efficiency. Thus there are major challenges in both materials development and new conceptual cell designs to improve the efficiency of this process.

Metson, James; McIntosh, Grant; Etzion, Ronny

351

Aluminium phthalocyanine chloride thin films for temperature sensing  

NASA Astrophysics Data System (ADS)

This study presents the fabrication and temperature sensing properties of sensors based on aluminium phthalocyanine chloride (AlPcCl) thin films. To fabricate the sensors, 50-nm-thick electrodes with 50-?m gaps between them are deposited on glass substrates. AlPcCl thin films with thickness of 50-100 nm are deposited in the gap between electrodes by thermal evaporation. The resistance of the sensors decreases with increasing thickness and the annealing at 100 °C results in an increase in the initial resistance of sensors up to 24%. The sensing mechanism is based on the change in resistance with temperature. For temperature varying from 25 °C to 80 °C, the change in resistance is up to 60%. Simulation is carried out and results obtained coincide with experimental data with an error of ±1%.

Muhammad Tariq Saeed, Chani; Abdullah, M. Asiri; Kh., S. Karimov; Atif, Khan Niaz; Sher Bhadar, Khan; Khalid., A. Alamry

2013-11-01

352

Simulating charge transport in tris(8-hydroxyquinoline) aluminium (Alq(3)).  

PubMed

We present a model of charge transport in organic solids which explicitly considers the packing and electronic structure of individual molecules. We simulate the time-of-flight mobility measurement in crystalline and disordered films of tris(8-hydroxyquinoline) aluminium (Alq(3)). The morphology of disordered Alq(3) is modelled on a molecular scale, and density functional theory is used to determine the electronic couplings between molecules. Without any fitting parameters we predict electron mobilities in the crystalline and disordered phases of approximately 1 and approximately 10(-4) cm(2) V(-1) s(-1), respectively. In good agreement with experiment we find that electron mobilities are two orders of magnitude greater than those of holes. We explain this difference in terms of the spatial extent of the frontier orbitals. Our results suggest that charge transport in disordered Alq(3) is dominated by a few highly conducting pathways. PMID:18368176

Kwiatkowski, J J; Nelson, J; Li, H; Bredas, J L; Wenzel, W; Lennartz, C

2008-04-14

353

Pulmonary Fibrosis in Workers Exposed to Finely Powdered Aluminium  

PubMed Central

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

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

1961-01-01

354

Aluminium administration is associated with enhanced hepatic oxidant stress that may be offset by dietary vitamin E in the rat  

PubMed Central

It has been proposed that aluminium toxicity may be mediated, at least in part, by free radical generation. We have investigated the effects of aluminium lactate administration on indices of hepatic oxidant stress, and the consequences of concomitant dietary vitamin E, in male albino Wistar rats. Aluminium lactate was administered for 4 weeks, by ip injection at 10 mg aluminium/kg body weight. Groups of animals received a chow diet containing 0, 5, 15, or 20 mg vitamin E/g of food. A control group of rats received a normal chow diet, without being injected with aluminium. The rats were killed after 4 weeks, and blood and liver tissue removed for the measurement of aluminium and markers of oxidative stress. Plasma and liver aluminium levels were increased in all groups of animals receiving aluminium lactate (P < 0.01), although these levels were significantly reduced in rats receiving concomitant vitamin E (P < 0.05). Aluminium treatment was associated with significantly increased levels of hepatic reactive oxygen species (ROS) (P < 0.01) that were attenuated by concomitant vitamin E (P < 0.05). Hepatic catalase and reduced glutathione levels were both reduced in animals treated with aluminium (P < 0.05).

Abubakar, M G; Taylor, A; Ferns, G A A

2003-01-01

355

Neutron Small Angle Scattering on Guinier-Preston Zones in Aluminium-Copper Alloys.  

National Technical Information Service (NTIS)

A study is made of stable and metastable aluminium-copper phase systems, hardening deposition mechanisms, electrical resistance, polycrystalline structures as well as the Guinier-Preston zone structure through small-angle neutron scattering methods. 50 re...

P. A. Prieto Pulido

1982-01-01

356

Direct determination of fluoride in aluminium reduction materials by using an ion-selective electrode.  

PubMed

Macro amounts of fluoride in aluminium reduction materials are successfully determined with a fluoride electrode. Except for anhydrous aluminium fluoride, which requires fusion with sodium hydroxide, samples are dissolved in aqueous media. Cryolite and sodium fluorosilicatc are dissolved in boiling sodium hydroxide solution. Other materials containing fluoride, such as fluorspar and the reduction cell bath and pot-lining, require dissolution in a hydrochloric acid solution of aluminium chloride. Potential interference from large amounts of aluminium (and calcium, if present) is eliminated and pH control attained by using ammoniacal sulphosalicylate (and EDTA). The procedures are reasonably rapid. Relative errors of less than 2% and a relative standard deviation of 1% are achieved. PMID:18961164

Palmer, T A

1972-10-01

357

Studies of aluminium coatings deposited by vacuum evaporation and magnetron sputtering.  

PubMed

The paper presents the results of investigations of the microstructures and properties of the aluminium coatings deposited by vacuum evaporation and magnetron sputtering. These coatings generally have a very refined microstructure with elongated nano-grains. However, the surface topography of the aluminium coating deposited by vacuum evaporation is more developed, its microstructure is less homogeneous and more porous. The residual tensile stresses in the aluminium coating deposited by magnetron sputtering are close to 130 MPa, and the texture is relatively pronounced. Vacuum evaporation does not induce residual stresses in the coatings and the texture is very weak. The results obtained indicate that the aluminium coatings produced by magnetron sputtering are more suitable for the diffusive Ti-Al intermetallic layers. PMID:20500421

Garbacz, H; Wieci?ski, P; Adamczyk-Cie?lak, B; Mizera, J; Kurzyd?owski, K J

2010-03-01

358

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

NASA Astrophysics Data System (ADS)

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.

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

359

Investigation of rate of thermal dissociation of basic aluminium potassium sulphate in hydrogen atmosphere  

Microsoft Academic Search

The rate of release of sulphur oxides from basic aluminium potassium sulphate was studied in a hydrogen atmosphere under isothermal-isobaric conditions, and the kinetic parameters of the process were determined by the statistical criteria method.

B. Pacewska

1990-01-01

360

Storage of Electrical Energy in Secondary Chemical Energy Carriers, Illustrated by the Example of Aluminium.  

National Technical Information Service (NTIS)

The thermochemical oxidation of aluminium with air was successfully demonstrated in a relatively small burner. Although direct caloric measurements of the furnace efficiency could not be made, analyses of the combustion products showed that the powdered-a...

W. Durisch O. Haas R. Muelli A. Tsukada H. R. Zumbrunnen

1985-01-01

361

Comparison of modification with strontium and the refining with antimony in A 356 aluminium alloys.  

National Technical Information Service (NTIS)

Strontium and Antimony treated A356 aluminium alloy samples were metallographically characterized in the as cast and solution and aged conditions. Antimony treated alloy has shown slower spheroidizing kinetics of the Silicon particles during solution trea...

R. Fuoco, E. R. Correa, A. V.O. Correa, M. Bocalini Junior

1992-01-01

362

Preparation of functionalized organoaluminiums by direct insertion of aluminium to unsaturated halides  

NASA Astrophysics Data System (ADS)

The preparation of polyfunctional organometallics is important in organic synthesis as these reagents are very popular nucleophiles. The preparation of functionalized aluminium reagents by direct insertion of aluminium powder is in general not possible. Such a reaction would be of special importance owing to the low price of aluminium compared with magnesium (it is half the price), the low toxicity of this metal and the chemoselectivity of the resultant organoaluminium reagents. We have now found that by adding catalytic amounts of selected metallic chlorides (TiCl4, BiCl3, InCl3 or PbCl2) in the presence of LiCl, aluminium powder inserts into various unsaturated iodides and bromides under mild conditions. These resulting new organoaluminium reagents undergo smooth Pd-catalysed cross-coupling and acylation reactions, as well as copper-catalysed allylic substitutions, affording various interesting products for pharmaceutical and material science applications.

Blümke, Tobias; Chen, Yi-Hung; Peng, Zhihua; Knochel, Paul

2010-04-01

363

Contribution of Nuclear Analysis Techniques to the Characterization of Aluminium Sheets and Anodic Oxidation Barrier Layers.  

National Technical Information Service (NTIS)

The use and the development of nuclear microanalysis has allowed the characterization of aluminium surfaces and oxidized phases obtained from industrial anodization procedures. The analytical performances of Rutherford backscattering of Li ions and alpha ...

M. Fallavier

1977-01-01

364

Fabrication of Highly Ordered Anodic Aluminium Oxide Templates on Silicon Substrates.  

National Technical Information Service (NTIS)

The controlled fabrication of highly ordered anodic aluminium oxide (AAO) templates of unprecedented pore uniformity directly on Si, enabled by new advances on two fronts -- direct and timed anodisation of a high-purity Al film of unprecedented thickness ...

A. Yin D. Cardimona J. Xu L. Guo M. Tzolov

2007-01-01

365

Aluminium and Alzheimer's disease: sites of aluminium binding in human neuroblastoma cells determined using 26Al and accelerator mass spectrometry  

NASA Astrophysics Data System (ADS)

The aluminium distribution between the major cell compartments of human neuroblastoma cells grown in culture has been determined using 21Al and accelerator mass spectrometry (AMS). Cells (IMR-32) were grown for eight days in a culture medium containing Al-EDTA (0.2mM) spiked with 26Al, harvested, and fractionated by standard biochemical techniques. 26Al in fractions after ashing to Al 2O 3 was determined by AMS using the 14UD accelerator at ANU Canberra. The cytoplasmic and nuclear cell compartments appeared to have reached diffusive equilibrium with the culture medium. Whilst 26Al was retained by the nuclear proteins and nuclear sap, 26Al did not appear to bind to the nucleic acids (DNA/RNA).

King, S. J.; Templar, J.; Miller, R. V.; Day, J. P.; Dobson, C. B.; Itzhaki, R. F.; Fifield, L. K.; Allan, G. L.

1994-06-01

366

Vector Addition Model  

NSDL National Science Digital Library

The Vector Addition model allows the user to practice vector addition of two vectors in two dimensions. You are given the magnitude and direction of the two vectors, and your goal is to fill in the nine values in the table (showing the x-component, y-component, and length) of the two vectors, and the resultant vector that is the sum of the first two vectors. The Vector Addition was created using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_bu_vector_addition.jar file will run the program if Java is installed.

Duffy, Andrew

2010-04-25

367

Effect of welding and weld repair on crack propagation behaviour in aluminium alloy 5083 plates  

Microsoft Academic Search

Aluminium alloy 5083 is used in the fabrication of lightweight, high-speed marine vessels. The high cyclic service stresses on such structures render welded joints in them fatigue-critical. This paper presents experimental investigations on fatigue crack behaviour of welded 5083-H321 aluminium alloy plates. Crack propagation in the heat-affected zone of welded specimens was determined from tests conducted on single edge-notched tension

Krishnakumar Shankar; Weidong Wu

2002-01-01

368

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

Microsoft Academic Search

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)

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

2005-01-01

369

Physically-based constitutive modelling of residual stress development in welding of aluminium alloy 2024  

Microsoft Academic Search

A finite element model has been developed to predict the evolution of residual stress and distortion which takes into account the history-dependence of the yield stress–temperature response of heat-treatable aluminium alloys during welding. The model was applied to TIG welding of 2024-T3 aluminium alloy, and the residual strain predictions validated using high resolution X-ray synchrotron diffraction. The goal was to

R. V. Preston; H. R.. Shercliff; P. J. Withers; S. Smith

2004-01-01

370

The aluminium\\/sapphire interface formation at high temperature: an AES and LEED study  

Microsoft Academic Search

We report the heteroepitaxy of Al(111) on ?-Al2O3(0001) realized at 470°C by aluminium evaporation and characterized by Auger spectroscopy (AES) and low energy electron diffraction (LEED). This crystalline growth is preceded by suboxide formation due to the superficial oxygens of the sapphire substrate, and the nucleation of aluminium crystallites with a (111) surface randomly oriented around the (0001) axis. Epitaxial

M. Vermeersch; F Malengreau; R Sporken; R Caudano

1995-01-01

371

Chemical interactions at the interface between aluminium nitride and iron oxide determined by XPS  

Microsoft Academic Search

The growth by RF reactive sputtering of aluminium nitride (AlN) at the surface of oxidised iron was studied by X-ray photoelectron spectroscopy (XPS). The observation of the substrate lines showed that the top layer of the iron oxide, constituted of Fe2O3 was first reduced into Fe3O4 by the incoming Al atoms to form an aluminium oxide. Moreover, an analysis of

F. Malengreau; V. Hautier; M. Vermeersch; R. Sporken; R. Caudano

1995-01-01

372

Perforation of AA5083-H116 aluminium plates with conical-nose steel projectiles – Calculations  

Microsoft Academic Search

The use of aluminium alloys in lightweight protective structures is increasing. Even so, the number of experimental and computational investigations that give detailed information on such problems is limited. In an earlier paper by some of the authors, perforation experiments were performed with 15–30mm thick AA5083-H116 aluminium plates and 20mm diameter, 98mm long, HRC 53 conical-nose hardened steel projectiles. In

T. Børvik; M. J. Forrestal; O. S. Hopperstad; T. L. Warren; M. Langseth

2009-01-01

373

Wood moisture content of coated wood\\/aluminium windows during three years of natural weathering  

Microsoft Academic Search

Wood\\/aluminium windows of a standard construction with different coating systems were installed in a facade facing south-east\\u000a on a building in Vienna. Over a period of three years the moisture content of the wooden frames and the climatic conditions\\u000a under the aluminium layers of the windows were measured. The results showed that humidity stress on the wooden frames of the

Gerhard Grüll; Thomas Anderl; Irene Schweiger

2005-01-01

374

Effect of heat treatment on properties of thixoformed high performance 2014 and 201 aluminium alloys  

Microsoft Academic Search

Tempering treatments T4, T5 and T6 have been applied after thixoforming to investigate the effects of heat treatment on microstructure and mechanical properties of thixoformed wrought aluminium alloy 2014, a ‘modified’ 2014 and high strength casting aluminium alloy 201. The ‘modified’ 2014 was a simplified version of 2014 with composition (wt%) Cu 3.87, Mg 0.6 and Si 0.14. The results

D. Liu; H. V. Atkinson; P. Kapranos; H. Jones

2004-01-01

375

Generation of aluminium–steel joints with laser-induced reactive wetting  

Microsoft Academic Search

A new mean of assembling steel to aluminium was developed, following previous work by German workers [1]. In this new method, a laser-induced aluminium melt pool spreads and wets a solid steel, to generate, after solidification a sound and resistant interface layer.Joint properties were investigated, in terms of surface aspects, interface microstructures and mechanical resistances under tensile testing, for non-galvanized

P. Peyre; G. Sierra; F. Deschaux-Beaume; D. Stuart; G. Fras

2007-01-01

376

A TEM study of precipitation and related microstructures in friction-stir-welded 6061 aluminium  

Microsoft Academic Search

Residual microstructures, including dynamic recrystallization and grain growth structures and a wide range of precipitation phenomena associated with a friction-stir-weld in a thin 6061-T6 aluminium plate have been systematically investigated utilizing light metallography and transmission electron microscopy. In this rather remarkable process, a hard steel head pin rotating at 400 r.p.m. was advanced into a solid 6061-aluminium plate at a

L. E. MURR; G. LIU; J. C. McCLURE

1998-01-01

377

First-principles pseudopotential study of an aluminium grain boundary containing sulphur atoms  

Microsoft Academic Search

The electronic structure of an aluminium grain boundary with segregated sulphur impurity atoms has been calculated by a first-principles pseudo-potential method. It is found that a sulphur atom bonds to only one of the neighbouring aluminium atoms. This bond is a mixed-character metallic-covalent bond which is stronger than the metallic Al-Al bonds. Electrons that participate in forming this bond are

Guang-Hong Lu; Masanori Kohyama; Ryoichi Yamamoto

2003-01-01

378

Laser assisted Friction Stir Welding of drawable steel-aluminium tailored hybrids  

Microsoft Academic Search

Steel aluminium Tailor Welded Hybrids are still mentioned to be difficult to be joint as intermetallic phases appear during\\u000a melting welding techniques. These phases are the reason for failure of the joint during loading or forming. As conventional\\u000a friction stir welding, a solid phase welding technology, is not feasible to join steel and aluminium, laser assistance for\\u000a preheating the steel

M. Merklein; A. Giera

2008-01-01

379

Determination of Trace Amounts of Aluminium in Water by SolidPhase Spectrophotometry  

Microsoft Academic Search

A method for the determination of trace amounts of aluminium based on Solid-Phase Spectrophotometry has been developed. Aluminium reacts with Eriochrome Cyanine R to give a highly coloured complex, which is fixed on a dextran type anion-exchanger. The absorbance of the gel, at 590 and 750 nm, packed in a 1-mm cell, is measured directly. The calibration graph is linear

J. M. Bosque-Sendra; M C. Valencia; S. Boudra

1994-01-01

380

Predicting tensile strength of friction stir welded AA6061 aluminium alloy joints by a mathematical model  

Microsoft Academic Search

AA6061 aluminium alloy (Al–Mg–Si alloy) has gathered wide acceptance in the fabrication of light weight structures requiring a high strength-to weight ratio and good corrosion resistance. Compared to the fusion welding processes that are routinely used for joining structural aluminium alloys, friction stir welding (FSW) process is an emerging solid state joining process in which the material that is being

K. Elangovan; V. Balasubramanian; S. Babu

2009-01-01

381

DEVELOPMENT OF A VARIABLE FLOW STRESS MACHINING THEORY FOR ALUMINIUM ALLOYS  

Microsoft Academic Search

This paper describes the development of a variable flow stress predictive machining theory for aluminium alloys. This theory is based on the Oxley's machining theory which allows for the high strain-rate\\/high temperature flow stress and thermal properties of the work materials and has so far been applied and tested for plain carbon steels.The developed predictive theory for aluminium has been

B. Kristyanto; P. Mathew; J. A. Arsecularatne

2002-01-01

382

The influence of cast method and anodizing parameters on structure and layer thickness of aluminium alloys  

Microsoft Academic Search

This elaboration presents the influence of casting method and anodic treatment parameters on thickness and structure of an anodic layer formed on aluminium alloys. As test materials it was employed the aluminium alloys AlSi12 and ALSi9Cu3, supplied by the Dutch company MIFA b.v., in which casting process and anodic treatment of samples were carried out also. It was presented herein

J. Konieczny; L. A. Dobrza?ski; K. Labisz; J. Duszczyk

2004-01-01

383

The behaviour of ion-implanted tungsten species during anodic oxidation of aluminium  

Microsoft Academic Search

Amorphous anodic oxide films have been formed at high efficiency on aluminium implanted with 0022-3727\\/31\\/17\\/002\\/img12 ions 0022-3727\\/31\\/17\\/002\\/img13 in order to study the behaviour of tungsten during film growth. The initial film is composed mainly of alumina because the outer layer of aluminium above the main implanted region of the substrate is oxidized. During this period, tungsten atoms, present in low

J. C. S. Fernandes; M. G. S. Ferreira; J. C. Soares; C. M. Jesus; C. M. Rangel; P. Skeldon; G. E. Thompson; X. Zhou; H. Habazaki; K. Shimizu

1998-01-01

384

Solidification mechanisms of unmodified and strontium-modified hypereutectic aluminium-silicon alloys  

Microsoft Academic Search

The effects of strontium on the solidification mode of hypereutectic aluminium-silicon alloys have been studied. Samples were prepared from an aluminium-17 wt% silicon-based alloy and strontium was added at several different concentrations. The development of the microstructure was investigated by cooling curve analysis, interrupted solidification experiments and optical and scanning electron microscopy. It was found that nucleation of primary silicon

K. Nogita; S. D. McDonald; A. K. Dahle

2004-01-01

385

Solidification mechanisms of unmodified and strontium-modified hypereutectic aluminium–silicon alloys  

Microsoft Academic Search

The effects of strontium on the solidification mode of hypereutectic aluminium–silicon alloys have been studied. Samples were prepared from an aluminium–17?wt% silicon-based alloy and strontium was added at several different concentrations. The development of the microstructure was investigated by cooling curve analysis, interrupted solidification experiments and optical and scanning electron microscopy. It was found that nucleation of primary silicon is

K. Nogita; S. D. McDonald; A. K. Dahle

2004-01-01

386

Generation of nano aluminium powder through wire explosion process and its characterization  

Microsoft Academic Search

The nano aluminium particles were produced in different ambience by the wire explosion process. The influence of pressure in the exploding wire chamber on the size of the particles was analyzed. Certain physico-chemical diagnostic studies, viz., wide angle X-ray diffraction (WAXD), thermo-gravimetric differential thermal analysis (TG–DTA) studies were carried out to characterize the produced nano aluminium powder. The compositions of

R.. Sarathi; T. K. Sindhu; S. R. Chakravarthy

2007-01-01

387

On the precipitation of magnesium silicide in irradiated aluminium–magnesium alloys  

Microsoft Academic Search

Thermal neutron irradiation of aluminium or its alloys causes the production of silicon by transmutation. In aluminium–magnesium alloys, the transmutation-produced silicon reacts with magnesium and forms small precipitates. The precipitation in irradiated Al–Mg alloys is similar to the early stage of aging in thermally treated Al–Mg–Si alloys. This study evidences the simultaneous generation of two crystallographically different precipitate types. On

M. Verwerft

2000-01-01

388

Aluminium content of drinking waters, fruit juices and soft drinks: contribution to dietary intake  

Microsoft Academic Search

Concentrations of aluminium in drinking waters (tap water, still mineral water and sparkling mineral water), fruit juices and soft drinks were determined using graphite furnace atomic absorption spectrometry (GFAAS) of samples processed with a HNO3–V2O5 acid digestion pre-treatment. In water samples, aluminium was determined directly. We verified the sensitivity, accuracy and precision of the method and ruled out matrix interferences.

Francisco F. López; Carmen Cabrera; M. Luisa Lorenzo; M. Carmen López

2002-01-01

389

Durability of aluminium-sealant joints in jet-fuel, water and antifreeze  

Microsoft Academic Search

The durability has been studied of aluminium-sealant joints immersed in jet-fuel, water and antifreeze. The sealants were a polysulfide, a fluorosilicone and a silicone, and durability was primarily controlled by the amount of fluid absorbed by the sealants. This gives polysulfide joints in antifreeze and silicone joints in jet-fuel very poor durability. The performance of polysulfide-aluminium joints was not significantly

J. Comyn; J. Day; S. J. Shaw

1997-01-01

390

Removal of various pollutants from wastewater by electrocoagulation using iron and aluminium electrode  

Microsoft Academic Search

The present study deals with removal of various pollutants from a real wastewater by electrocoagulation treatment. Combined wastewater from one of the Delhi industrial areas was collected and treated by electrocoagulation process using iron and aluminium electrodes. Removal of Cr, Zn, Ni and Cu were achieved up to 100, 98.71, 69.22 and 48.08% respectively using aluminium electrode while Cr, Cu,

Asheesh Kumar Yadav; Lakhvinder Singh; Ayusman Mohanty; Santosh Satya; T. R. Sreekrishnan

2012-01-01

391

Defluoridation of Sahara water by small plant electrocoagulation using bipolar aluminium electrodes  

Microsoft Academic Search

The purpose of this paper is to propose an efficient and low cost defluoridation process based on electrocoagulation with aluminium bipolar electrodes. The performance of a pilot scale electrochemical reactor equipped with aluminium bipolar electrodes with an anode active area surface of about 1.6 m2 was studied. The pilot study yielded promising results, suggesting that further in-depth development studies are

N. Mameri; H. Lounici; D. Belhocine; H. Grib; D. L. Piron; Y. Yahiat

2001-01-01

392

Characterization of individual aerosol particles in workroom air of aluminium smelter potrooms.  

PubMed

Aerosol particles with aerodynamic diameters between 0.18 and 10 microm were collected in the workroom air of two aluminium smelter potrooms with different production processes (Soderberg and Prebake processes). Size, morphology and chemical composition of more than 2000 individual particles were determined by high resolution scanning electron microscopy and energy-dispersive X-ray microanalysis. Based on chemical composition and morphology, particles were classified into different groups. Particle groups with a relative abundance above 1%(by number) include aluminium oxides, cryolite, aluminium oxides-cryolite mixtures, soot, silicates and sea salt. In both production halls, mixtures of aluminium oxides and cryolite are the dominant particle group. Many particles have fluoride-containing surface coatings or show agglomerations of nanometer-sized fluoride-containing particles on their surface. The phase composition of approximately 100 particles was studied by transmission electron microscopy. According to selected area electron diffraction, sodium beta-alumina (NaAl(11)O(17)) is the dominant aluminium oxide and cryolite (Na(3)AlF(6)) the only sodium aluminium fluoride present. Implications of our findings for assessment of adverse health effects are discussed. PMID:15877161

Hoflich, Burkard L W; Weinbruch, Stephan; Theissmann, Ralf; Gorzawski, Hauke; Ebert, Martin; Ortner, Hugo M; Skogstad, Asbjorn; Ellingsen, Dag G; Drablos, Per A; Thomassen, Yngvar

2005-05-01

393

Toxicity of acid aluminium-rich water to seven freshwater fish species: a comparative laboratory study.  

PubMed

The present study focuses on the relative sensitivity among freshwater fish species to aqueous aluminium. Seven common Scandinavian fish species were exposed to acidic Al-rich water, acidic Al-poor water, and approximately neutral water as a control. The relative sensitivity among the species to an acute aluminium challenge was documented, and was in the following order: Atlantic salmon, Salmo salar, as the most sensitive; then roach, Rutilus rutilus; minnow, Phoxinus phoxinus; perch, Perca fluviatilis; grayling, Thymallus thymallus; brown trout, Salmo trutta; and Arctic char, Salvelinus alpinus. Substantial mortality was observed in all species when exposed to the Al-rich medium. Some mortality was also observed in minnow, roach, and brown trout exposed to the acidic Al-poor medium and the control medium. A high resistance to aluminium was observed in Arctic char, while perch was found to be more sensitive to aluminium than expected and, for the first time, a toxic response to aqueous aluminium in grayling was documented. Through controlled experimental studies, the results confirm that aluminium is an important factor in the toxicity of acidified waters to freshwater fish species. PMID:15093412

Poléo, A B; ØStbye, K; Øxnevad, S A; Andersen, R A; Heibo, E; Vøllestad, L A

1997-01-01

394

[Characteristic of natural organic matter removal by ferric and aluminium coagulation].  

PubMed

Natural organic matter removal efficiency and characteristic by ferric chloride and aluminium sulphate were studied. Results showed that ferric chloride was effective in natural organic matter removal when coagulant dosage was higher than 15 mg/L, while aluminium was effective at lower dosage. The TOC of water was reduced to 4.19 mg/L and 9 mg/L at a dosage of 10 mg/L for aluminium sulphate and ferric chloride respectively, while TOC was reduced to 2.44 mg/L and 1.69 mg/L at the dosage of 20 mg/L. Ferric chloride decreased pH sharply than aluminium sulphate which made hydrolysate more positive and attachable for natural organic matter. UV254 and SUVA results showed that ferric chloride removed more conjugate structure materials and unsaturated band contents than aluminium. Ferric chloride was more effective in reducing lower molecular weight organic matter and hydrophilic substances than aluminium, when the dosage of coagulant was 20 mg/L, the removal efficiency of relative molecular weight below 10 000 was 16.4% and 6.1% respectively, while aluminum was more effective in high molecular weight matter removal than ferric chloride. PMID:18624177

Zhou, Ling-Ling; Zhang, Yong-Ji; Sun, Li-Hua; Li, Gui-Bai

2008-05-01

395

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

NASA Astrophysics Data System (ADS)

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.

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

2014-06-01

396

Additive similarity trees  

Microsoft Academic Search

Similarity data can be represented by additive trees. In this model, objects are represented by the external nodes of a tree, and the dissimilarity between objects is the length of the path joining them. The additive tree is less restrictive than the ultrametric tree, commonly known as the hierarchical clustering scheme. The two representations are characterized and compared. A computer

Shmuel Sattath; Amos Tversky

1977-01-01

397

Chloro-sulphur additive  

SciTech Connect

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.

Lenack, A.L.

1980-10-14

398

Carbamate deposit control additives  

SciTech Connect

Deposit control additives for internal combustion engines are provided which maintain cleanliness of intake systems without contributing to combustion chamber deposits. The additives are poly(oxyalkylene) carbamates comprising a hydrocarbyloxyterminated poly(Oxyalkylene) chain of 2-5 carbon oxyalkylene units bonded through an oxycarbonyl group to a nitrogen atom of ethylenediamine.

Honnen, L.R.; Lewis, R.A.

1980-11-25

399

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

PubMed

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

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

2013-01-01

400

Growth mode and electronic structure of copper films on aluminium substrates  

NASA Astrophysics Data System (ADS)

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 commensurate with the Al(111) substrate with an interatomic distance typical of bulk Cu. Electronic structure of films grown at 300 K converges to that of a bulk Cu single crystal, convergence being essentially complete at a coverage of 10 monolayers. In contrast, growth occurs in a long-range disordered fashion up to relatively high coverages on Al(100) probably in the form of densely packed Cu clusters above a mixed Cu/Al interfacial region. For submonolayer coverages the work function remains close to the clean Al values, increasing to 4.7 and 4.5 eV for (111) and (100) faces, respectively, in the range from 1 to 4 monolayers. Additional studies carried out at elevated (375 K) and low temperature (120 K) allow postulation of a fully coherent model of the complex growth and electronic properties of this particular metal-on-metal system.

Barnes, C. J.; Asonen, H.; Salokatve, A.; Pessa, M.

1987-05-01

401

Modelling of liquid metal flow and oxide film defects in filling of aluminium alloy castings  

NASA Astrophysics Data System (ADS)

The liquid metal flow behaviours in different runner system designs have important effects on the mechanical strength of aluminium alloy castings. In this paper, a new model has been developed which is a two-dimensional program using a finite difference technique and the Marker and Cell (MAC) method to simulate the flow of liquid metal during filling a mould. In the program the Eulerian method has been used for the liquid metal flow, while the Oxide Film Entrainment Tracking Algorithm (OFET) method (a Lagrangian method) has been used to simulate the movement of the oxide film on the liquid metal surface or in the liquid metal flow. Several examples have been simulated and tested and the relevant results were obtained. These results were compared with measured bending strengths. It was found that the completed program was capable of simulating effectively the filling processes of different runner systems. The simulation results are consistent with the experiment. In addition, the program is capable of providing clearer images for predicting the distribution of the oxide film defects generated during filling a mould.

Dai, X.; Jolly, M.; Yang, X.; Campbell, J.

2012-07-01

402

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

NASA Astrophysics Data System (ADS)

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.

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

403

The beneficial effect of aluminium and the role of citrate in Al accumulation in Melastoma malabathricum.  

PubMed

* Here we investigated the beneficial effect of aluminium (Al) on the development of the Al accumulating plant Melastoma malabathricum. * Seedlings of M. malabathricum were cultivated in a nutrient solution containing 0.5 mM Al and compared with barley (Hordeum vulgare). In addition, roots of M. malabathricum were divided into one part growing in a nutrient solution, and the other part growing in a calcium solution. Al (0.5 mM) was applied to either solution. * Al-induced improvements of the root activity contributed to a growth enhancement in M. malabathricum. Al exposure without nutrients did not increase root growth and Al accumulation in the leaves. The beneficial effect, however, was induced by the combination of Al and nutrients. * We suggest that without nutrients roots are not able to synthesize an adequate amount of citrate that is required for transporting Al to the leaves. High Al levels in the plant tissues and/or an interaction of Al with particular nutrient elements in the apoplast of root cells appear to be essential to exert the beneficial effect of Al. PMID:15720688

Watanabe, Toshihiro; Jansen, Steven; Osaki, Mitsuru

2005-03-01

404

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

PubMed

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

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

2012-08-01

405

Awesome Addition Games  

NSDL National Science Digital Library

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 ...

Smith, Ms.

2010-10-14

406

Polyimide processing additives  

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

407

Polyimide processing additives  

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

408

Color Chips - Addition  

NSDL National Science Digital Library

This virtual manipulative provides students with practice adding positive and negative integers. Students are given an addition problem, and using one-to-one correspondence, the student is able to see what happens when adding negative integers. The addition problems can be computer generated or teacher generated and there is a free play mode which allows the student to practice with the chips and become familiar with the process of moving the chips around the page, and creating a visual representation of an addition problem with integers.

University, Utah S.

2011-06-28

409

Vector Addition Patterns Model  

NSDL National Science Digital Library

The Vector Addition Patterns model illustrates the tail-to-tip method of adding vectors. The table at the bottom shows the components and lengths of the vectors. You can also rotate the vectors and trace out some interesting patterns. The Vector Addition Patterns model was created using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_bu_vector_addition_patterns.jar file will run the program if Java is installed.

Duffy, Andrew

2010-05-02

410

X-ray back-lighter characterization for iron opacity measurements using laser-produced aluminium K-alpha emission  

Microsoft Academic Search

Aluminium Kalpha emission (1.5 keV) produced by an 8 J, 500 ps, Nd:glass laser incident at 45° onto a layered target of 0.8 µm thick aluminium (front side) and 1 µm thick iron (backside) has been used to probe the opacity of iron plasma. Source broadened spectroscopy and continuum emission analysis show that whole beam self-focusing within the aluminium plasma

A. K. Rossall; L. M. R. Gartside; S. Chaurasia; S. Tripathi; D. S. Munda; N. K. Gupta; L. J. Dhareshwar; J. Gaffney; S. J. Rose; G. J. Tallents

2010-01-01

411

Effects of Welding Processes and Post-Weld Aging Treatment on Fatigue Behavior of AA2219 Aluminium Alloy Joints  

NASA Astrophysics Data System (ADS)

AA2219 aluminium alloy square butt joints without filler metal addition were fabricated using gas tungsten arc welding (GTAW), electron beam welding (EBW), and friction stir welding (FSW) processes. The fabricated joints were post-weld aged at 175 °C for 12 h. The effect of three welding processes and post-weld aging (PWA) treatment on the fatigue properties is reported. Transverse tensile properties of the welded joints were evaluated. Microstructure analysis was also carried out using optical and electron microscopes. It was found that the post-weld aged FSW joints showed superior fatigue performance compared to EBW and GTAW joints. This was mainly due to the formation of very fine, dynamically recrystallized grains and uniform distribution of fine precipitates in the weld region.

Malarvizhi, S.; Balasubramanian, V.

2011-04-01

412

Food Additives and Hyperkinesis  

ERIC Educational Resources Information Center

The hypothesis that food additives are causally associated with hyperkinesis and learning disabilities in children is reviewed, and available data are summarized. Available from: American Medical Association 535 North Dearborn Street Chicago, Illinois 60610. (JG)

Wender, Ester H.

1977-01-01

413

AdditionalBooks  

Cancer.gov

While we tried to include potentially useful resources, this website is not exhaustive. New and additional resources may be available. Please let us know if there is a resource you would like to be included.

414

Smog control fuel additives  

SciTech Connect

A method is described of controlling, reducing or eliminating, ozone and related smog resulting from photochemical reactions between ozone and automotive or industrial gases comprising the addition of iodine or compounds of iodine to hydrocarbon-base fuels prior to or during combustion in an amount of about 1 part iodine per 240 to 10,000,000 parts fuel, by weight, to be accomplished by: (a) the addition of these inhibitors during or after the refining or manufacturing process of liquid fuels; (b) the production of these inhibitors for addition into fuel tanks, such as automotive or industrial tanks; or (c) the addition of these inhibitors into combustion chambers of equipment utilizing solid fuels for the purpose of reducing ozone.

Lundby, W.

1993-06-29

415

Palmer boathouse addition <  

NSF Publications Database

... EAM NSF Org: OD / OPP Date : January 31, 1991 File : opp93021 OFFICE OF SAFETY, ENVIRONMENT AND ... Palmer Station Boathouse Addition) To: Files (S.7 - Environment) On January 16, 1991, the civilian ...

416

Water defluoridation by aluminium oxide-manganese oxide composite material.  

PubMed

In this study, aluminium oxide-manganese oxide (AOMO) composite material was synthesized, characterized, and tested for fluoride removal in batch experiments. AOMO was prepared from manganese(II) chloride and aluminium hydroxide. The surface area of AOMO was found to be 30.7m2/g and its specific density was determined as 2.78 g/cm3. Detailed investigation of the adsorbent by inductively coupled plasma-optical emission spectrometry, inductively coupled plasma-mass spectrometry, and ion chromatography (for sulphate only) showed that it is composed of Al, Mn, SO4, and Na as major components and Fe, Si, Ca, and Mg as minor components. Thermogravimetric analysis was used to study the thermal behaviour of AOMO. X-ray diffraction analysis showed that the adsorbent is poorly crystalline. The point of zero charge was determined as 9.54. Batch experiments (by varying the proportion of MnO, adsorbent dose, contact time, initial F concentration, and raw water pH) showed that fluoride removal efficiency ofAOMO varied significantly with percentage of MnO with an optimum value of about I11% of manganese oxide in the adsorbent. The optimum dose of the adsorbent was 4 g/L which corresponds to the equilibrium adsorption capacity of 4.8 mg F-/g. Both the removal efficiency and adsorption capacity showed an increasing trend with an increase in initial fluoride concentration of the water. The pH for optimum fluoride removal was found to be in the range between 5 and 7. The adsorption data were analysed using the Freundlich, Langmuir, and Dubinirn-Radushkevich models. The minimum adsorption capacity obtained from the non-linear Freundlich isotherm model was 4.94 mg F-/g and the maximum capacity from the Langmuir isotherm method was 19.2mg F-/g. The experimental data of fluoride adsorption on AOMO fitted well to the Freundlich isotherm model. Kinetic studies showed that the adsorption is well described by a non-linear pseudo-second-order reaction model with an average rate constant of 3.1 x 10(-2) g/min mg. It is concluded that AOMO is a highly promising adsorbent for the removal of excess fluoride from drinking water. PMID:24956783

Alemu, Sheta; Mulugeta, Eyobel; Zewge, Feleke; Chandravanshi, Bhagwan Singh

2014-08-01

417

Solution phase chemical synthesis of nano aluminium particles stabilized in poly(vinylpyrrolidone) and poly(methylmethacrylate) matrices.  

PubMed

The reduction of aluminium trichloride by lithium aluminium hydride in the presence of poly(vinylpyrrolidone) or poly(methylmethacrylate) in mesitylene yielded nano aluminium particles in the matrices of respective polymers. Solution phase synthesis methodology was used successfully to produce composites of various Al/polymer ratios. The composites were characterized by powder XRD patterns and 27Al-NMR with MAS spectroscopic study. The method was useful to produce up to 10 g of nano aluminium that were pure and stable. PMID:20648295

Ghanta, Sekher Reddy; Muralidharan, Krishnamurthi

2010-06-01

418

Effect of aluminium on migratory and invasive properties of MCF-7 human breast cancer cells in culture.  

PubMed

Aluminium (Al) has been measured in human breast tissue, nipple aspirate fluid and breast cyst fluid, and recent studies have shown that at tissue concentrations, aluminium can induce DNA damage and suspension growth in human breast epithelial cells. This paper demonstrates for the first time that exposure to aluminium can also increase migratory and invasive properties of MCF-7 human breast cancer cells. Long-term (32 weeks) but not short-term (1 week) exposure of MCF-7 cells to 10(-4) M aluminium chloride or 10(-4) M aluminium chlorohydrate increased motility of the cells as measured by live cell imaging (cumulative length moved by individual cells), by a wound healing assay and by migration in real time through 8 ?m pores of a membrane using xCELLigence technology. Long-term exposure (37 weeks) to 10(-4) M aluminium chloride or 10(-4) M aluminium chlorohydrate also increased the ability of MCF-7 cells to invade through a matrigel layer as measured in real time using the xCELLigence system. Although molecular mechanisms remain to be characterized, the ability of aluminium salts to increase migratory and invasive properties of MCF-7 cells suggests that the presence of aluminium in the human breast could influence metastatic processes. This is important because mortality from breast cancer arises mainly from tumour spread rather than from the presence of a primary tumour in the breast. PMID:23896199

Darbre, Philippa D; Bakir, Ayse; Iskakova, Elzira

2013-11-01

419

Aluminium reduces sugar uptake in tobacco cell cultures: a potential cause of inhibited elongation but not of toxicity  

PubMed Central

Aluminium is well known to inhibit plant elongation, but the role in this inhibition played by water relations remains unclear. To investigate this, tobacco (Nicotiana tabacum L.) suspension-cultured cells (line SL) was used, treating them with aluminium (50 ?M) in a medium containing calcium, sucrose, and MES (pH 5.0). Over an 18 h treatment period, aluminium inhibited the increase in fresh weight almost completely and decreased cellular osmolality and internal soluble sugar content substantially; however, aluminium did not affect the concentrations of major inorganic ions. In aluminium-treated cultures, fresh weight, soluble sugar content, and osmolality decreased over the first 6 h and remained constant thereafter, contrasting with their continued increases in the untreated cultures. The rate of sucrose uptake, measured by radio-tracer, was reduced by approximately 60% within 3 h of treatment. Aluminium also inhibited glucose uptake. In an aluminium-tolerant cell line (ALT301) isogenic to SL, all of the above-mentioned changes in water relations occurred and tolerance emerged only after 6 h and appeared to involve the suppression of reactive oxygen species. Further separating the effects of aluminium on elongation and cell survival, sucrose starvation for 18 h inhibited elongation and caused similar changes in cellular osmolality but stimulated the production of neither reactive oxygen species nor callose and did not cause cell death. We propose that the inhibition of sucrose uptake is a mechanism whereby aluminium inhibits elongation, but does not account for the induction of cell death.

Abdel-Basset, Refat; Ozuka, Shotaro; Demiral, Tijen; Furuichi, Takuya; Sawatani, Ikuo; Baskin, Tobias I.; Matsumoto, Hideaki; Yamamoto, Yoko

2010-01-01

420

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

NASA Astrophysics Data System (ADS)

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.

Eljaafari, Samira

421

Phenylethynyl Containing Reactive Additives  

NASA Technical Reports Server (NTRS)

Phenylethynyl containing reactive additives were prepared from aromatic diamine, containing phenylethvnvl groups and various ratios of phthalic anhydride and 4-phenylethynviphthalic anhydride in glacial acetic acid to form the imide in one step or in N-methyl-2-pvrrolidinone to form the amide acid intermediate. The reactive additives were mixed in various amounts (10% to 90%) with oligomers containing either terminal or pendent phenylethynyl groups (or both) to reduce the melt viscosity and thereby enhance processability. Upon thermal cure, the additives react and become chemically incorporated into the matrix and effect an increase in crosslink density relative to that of the host resin. This resultant increase in crosslink density has advantageous consequences on the cured resin properties such as higher glass transition temperature and higher modulus as compared to that of the host resin.

Connell, John W. (Inventor); Smith, Joseph G., Jr. (Inventor); Hergenrother, Paul M. (Inventor)

2002-01-01

422

Phenylethynyl Containing Reactive Additives  

NASA Technical Reports Server (NTRS)

Phenylethynyl containing reactive additives were prepared from aromatic diamines containing phenylethynyl groups and various ratios of phthalic anhydride and 4-phenylethynylphthalic anhydride in glacial acetic acid to form the imide in one step or in N-methyl-2-pyrrolidi none to form the amide acid intermediate. The reactive additives were mixed in various amounts (10% to 90%) with oligomers containing either terminal or pendent phenylethynyl groups (or both) to reduce the melt viscosity and thereby enhance processability. Upon thermal cure, the additives react and become chemically incorporated into the matrix and effect an increase in crosslink density relative to that of the host resin. This resultant increase in crosslink density has advantageous consequences on the cured resin properties such as higher glass transition temperature and higher modulus as compared to that of the host resin.

Connell, John W. (Inventor); Smith, Joseph G., Jr. (Inventor); Hergenrother, Paul M. (Inventor)

2002-01-01

423

Electrocoagulation efficiency of the tannery effluent treatment using aluminium electrodes.  

PubMed

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

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

424

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

PubMed

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

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

2009-09-01

425

Mechanism of stabilization of dicalcium silicate solid solution with aluminium.  

PubMed

Stoichiometric dicalcium silicate, Ca2SiO4, displays a well-known polymorphism with temperature. When this phase is doped by a range of elements, belite, one of the main phases of cements, is generated. Here, we thoroughly study the aluminum doping of dicalcium silicate. This type of study is important for cement characterization and also from a basic point of view. Ca2Si(1-2x)Al(2x)O(4-x)?(x) (x = 0, 0.010, 0.014, 0.03) has been prepared and studied by X-ray powder diffraction and the Rietveld method. The limiting composition has been established as Ca2Si0.972Al0.028O3.986?0.014. The (27)Al MAS NMR band located close to ~-70 ppm is ascribed to tetrahedral environments, in agreement with the proposed aliovalent Si/Al atomic substitution mechanism. Thermal analysis measurements under a wet atmosphere indirectly confirm the increase of oxygen vacancies as the amount of incorporated protons increases with the aluminium content. A thorough electrical characterization has been carried out including overall conductivity measurements under wet and dry atmospheres and conductivity as a function of the oxygen partial pressure. The samples show oxide anion conductivity with a small p-type electronic contribution under oxidizing conditions. These compounds display a very important proton contribution to the overall conductivities under humidified atmospheres. PMID:24292166

Cuesta, Ana; Aranda, Miguel A G; Sanz, Jesús; de la Torre, Angeles G; Losilla, Enrique R

2014-02-01

426

Doped calcium-aluminium-phosphate cements for biomedical applications.  

PubMed

Calcium-aluminium-phosphate cements (CAPCs) for biomedical applications, mainly intended for applications in the dental field as non-resorbable fillers, were obtained by reacting Ca-aluminates compounds, i.e. CaO·Al(2)O(3) (CA) and CaO·2 Al(2)O(3) (CA(2)), with Al(H(2)PO(4))(3) aqueous solution. Hydroxyapatite was also introduced as a bioactive dispersed phase. Suitable elements like Sr and La were used to increase the radiopacity of the set yielded pastes towards X-ray wavelength used in clinical diagnostic radiographic equipments. La and Sr doped Ca-aluminates powders have been synthesized by solid state reaction at 1,400°C from a mixture of CaCO(3), Al(2)O(3), La(2)O(3) and SrCO(3). The characteristics of the obtained powders were analyzed and related to the starting compositions and synthesis procedures. The microstructure, setting time, radiopacity and compressive strength of the CAPCs have been investigated and discussed. PMID:21165760

Medri, V; Mazzocchi, M; Bellosi, A

2011-02-01

427

Aspects of fabrication aluminium matrix heterophase composites by suspension method  

NASA Astrophysics Data System (ADS)

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.

Dolata, A. J.; Dyzia, M.

2012-05-01

428

The interpretation of polycrystalline coherent inelastic neutron scattering from aluminium  

PubMed Central

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.

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

2013-01-01

429

Aluminium exposure disrupts elemental homeostasis in Caenorhabditis elegans†  

PubMed Central

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.

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

2013-01-01

430

Evidence of superdense aluminium synthesized by ultrafast microexplosion  

SciTech Connect

At extreme pressures and temperatures, such as those inside planets and stars, common materials form new dense phases with compacted atomic arrangements and unusual physical properties. The synthesis and study of new phases of matter at pressures above 100 GPa and temperatures above 10{sup 4} K - warm dense matter - may reveal the functional details of planet and star interiors, and may lead to materials with extraordinary properties. Many phases have been predicted theoretically that may be realized once appropriate formation conditions are found. Here we report the synthesis of a superdense stable phase of body-centred-cubic aluminium, predicted by first-principles theories to exist at pressures above 380 GPa. The superdense Al phase was synthesized in the non-equilibrium conditions of an ultrafast laser-induced microexplosion confined inside sapphire ({alpha}-Al{sub 2}O{sub 3}). Confined microexplosions offer a strategy to create and recover high-density polymorphs, and a simple method for tabletop study of warm dense matter.

Vailionis, Arturas; Gamaly, Eugene G.; Mizeikis, Vygantas; Yang, Wenge; Rode, Andrei V.; Juodkazis, Saulius (Swinburne); (Stanford); (CIW); (ANU); (Shinshu-MED)

2011-09-20

431

Industrial hygiene survey in an aluminium reduction plant in India.  

PubMed

This study reports a work-environmental assessment and workers' exposure in a major prebake type aluminium smelter in India. Levels of known health hazards in and near the main smelting operations viz., the Potroom, the Carbon area, the Butt section, the Rodding shop, the Bath preparing area and the Casthouse were measured. Dustiness in general was high to excessively high. Mean levels of respirable dust (PM10) in air in the three dustiest areas were 24.07 mg/m3 in the Carbon areas, 27.57 mg/m3 in the Bath preparing and 4.44 mg/m3 in the Rodding shop. 40- 60% of the particles were less than 5 microm in size. 0.5- 2.82% particulate fluoride was obtained in the size fraction 0.4- 4.7 microm of the Potroom air. Naturally, exposures to total dusts were very high in these processes. The background levels of NOx and SO2 and fluorides (gaseous and particulate) were found to be within the prescribed Indian Standards. Higher exposures to gaseous and particulate fluoride, 3.85 and 6.53 mg/m3 respectively, were observed among the Rodding shop workers. The levels ofpolycyclic aromatic hydrocarbons (PAHs) were deemed to be excessive in the Carbon area. Measurements of heat stress were made in winter and were found to be lower than the prescribed limit. PMID:18783008

Mukherjee, Ashit K; Ravichandran, Beerappa; Bhattacharya, Sanat K; Roy, Sanjit K; Ahmed, Sabir; Thakur, Sridhar; Saiyed, Habibullah N

2008-09-01

432

Ultrasonic Rayleigh Wave Enhancements from Angled Defects in Aluminium  

NASA Astrophysics Data System (ADS)

Non-linear enhancements of ultrasonic surface wave amplitude and frequency have been observed when an incident wave interacts with a surface defect. Previous measurements of surface wave interactions with defects have considered only those that are inclined normal to the surface. Here, the enhancement effects have been studied in aluminium samples with machined slots of fixed length and of varying angle to the horizontal; the degree of enhancement was studied as a function of defect angle using both a scanning laser source, and a scanning laser detector. An automated scanning system has been developed for use with the detector, an IOS two-wave mixer interferometer, capable of measuring the out-of-plane surface displacement on rough surfaces. B-scans, consisting of many A-scans stacked together, were used to identify wave modes present in the near field, the arrival times of which are dependent on the angle of the defect. The observed enhancement is caused by superposition of the incident Rayleigh wave with reflected and mode converted waves, thereby making it angle dependent.

Clough, A. R.; Dutton, B.; Edwards, R. S.

2011-06-01

433

Additives in plastics.  

PubMed Central

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.

Deanin, R D

1975-01-01

434

Extraction chromatography of aluminium (III) and mutual separation of aluminium (III), gallium (III), indium (III) and thallium (III) with N-n-octylaniline.  

PubMed

A selective method has been developed for the extraction chromatography of aluminium (III) and its separation from several metal ions with a chromatographic column containing N-n-octylaniline (a liquid anion exchanger) coated on silanized silica gel as a stationary phase. The aluminium (III) was quantitatively extracted with the 0.065 mol/L N-n-octylaniline in 0.013 to 0.05 mol/L sodium succinate at a flow rate of 1.0 mL/min. The extracted metal ion has been recovered by eluting with 25.0 mL of 0.05 mol/L hydrochloric acid and estimated spectrophotometrically with aurintricarboxylic acid. The effects of the acid concentration, the reagent concentration, the flow rate and the eluting agents have been investigated. The log-log plots of distribution coefficient (Kd (Al (III))) versus N-n-octylaniline concentration in 0. 005 and 0. 007 mol/L sodium succinate gave the slopes of 0.5 and 0.7 respectively and showed the probable composition of the extracted species was 1:1 (metal to amine ratio) and the nature of extracted species was [RR'NH2(+), Al succinate2(-)]org. The extraction of aluminium(III) was carried out in the presence of various ions to ascertain the tolerance limit of individual ions. Aluminium(III) has been separated from multicomponent mixtures, pharmaceutical samples and synthetic mixtures corresponding to alloys. A scheme for mutual separation of aluminium (III), indium (III), gallium (III) and thallium (III) has been developed by using suitable masking agents. The method is fast, accurate and precise. PMID:23285976

Phule, Sachin R; Aher, Haribhau R; Kuchekar, Shashikant R; Han, Sung-H

2012-09-01

435

Fluency with Basic Addition  

ERIC Educational Resources Information Center

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

Garza-Kling, Gina

2011-01-01

436

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.

2013-07-23

437

Adverse events after immunisation with aluminium-containing DTP vaccines: systematic review of the evidence.  

PubMed

We have reviewed evidence of adverse events after exposure to aluminium-containing vaccines against diphtheria, tetanus, and pertussis (DTP), alone or in combination, compared with identical vaccines, either without aluminium or containing aluminium in different concentrations. The study is a systematic review with meta-analysis. We searched the Cochrane Vaccines Field Register, the Cochrane Library, Medline, Embase, Biological Abstracts, Science Citation Index, and the Vaccine Adverse Event Reporting System website for relevant studies. Reference lists of retrieved articles were scanned for further studies. We included randomised and semi-randomised trials and comparative cohort studies if the report gave sufficient information for us to extract aluminium concentration, vaccine composition, and safety outcomes. Two reviewers extracted data in a standard way from all included studies and assessed the methodological quality of the studies. We identified 35 reports of studies and included three randomised trials, four semi-randomised trials, and one cohort study. We did a meta-analysis of data from five studies around two main comparisons (vaccines containing aluminium hydroxide vs no adjuvant in children aged up to 18 months and vaccines containing different types of aluminium vs no adjuvants in children aged 10-16 years). In young children, vaccines with aluminium hydroxide caused significantly more erythema and induration than plain vaccines (odds ratio 1.87 [95% CI 1.57-2.24]) and significantly fewer reactions of all types (0.21 [0.15-0.28]). The frequencies of local reactions of all types, collapse or convulsions, and persistent crying or screaming did not differ between the two cohorts of the trials. In older children, there was no association between exposure to aluminium-containing vaccines and onset of (local) induration, swelling, or a raised temperature, but there was an association with local pain lasting up to 14 days (2.05 [1.25-3.38]). We found no evidence that aluminium salts in vaccines cause any serious or long-lasting adverse events. Despite a lack of good-quality evidence we do not recommend that any further research on this topic is undertaken. PMID:14871632

Jefferson, Tom; Rudin, Melanie; Di Pietrantonj, Carlo

2004-02-01

438

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

SciTech Connect

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.

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

439

Shear modulus of shock-compressed LY12 aluminium up to melting point  

NASA Astrophysics Data System (ADS)

Asymmetric plate impact experiments are conducted on LY12 aluminium alloy in a pressure range of 85-131 GPa. The longitudinal sound speeds are obtained from the time-resolved particle speed profiles of the specimen measured with Velocity Interferometer System for Any Reflector (VISAR) technique, and they are shown to be good agreement with our previously reported data of this alloy in a pressure range of 20-70 GPa, and also with those of 2024 aluminium reported by McQueen. Using all of the longitudinal speeds and the corresponding bulk speeds calculated from the Gruneisen equation of state (EOS), shear moduli of LY12 aluminium alloy are obtained. A comparison of the shear moduli in the solid phase region with those estimated from the Steinberg model demonstrate that the latter are systematically lower than the measurements. By re-analysing the pressure effect on the shear modulus, a modified equation is proposed, in which the pressure term of P/?1/3 in the Steinberg model is replaced by a linear term. Good agreement between experiments and the modified equation is obtained, which implies that the shear modulus of LY12 aluminium varies linearly both with pressure and with temperature throughout the whole solid phase region. On the other hand, shear modulus of aluminium in a solid-liquid mixed phrase region decreases gradually and smoothly, a feature that is very different from the drastic dropping at the melting point under static conditions.

Yu, Yu-Ying; Tan, Hua; Hu, Jian-Bo; Dai, Cheng-Da

2008-01-01

440

Protection of aluminium foil AA8021 by molybdate-based conversion coatings  

NASA Astrophysics Data System (ADS)

A quick method for surface treatment of aluminium foil with environment-friendly and effective molybdate-based coating was developed in this study. Aluminium foil samples were treated with molybdate-based solution. The microstructure and composition of the resulting molybdate-based conversion coatings were explored by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray photoelectric spectroscopy (XPS). We found that the molybdate-based conversion coating was composed mainly of MoO3, (MoO3)x(P2O5)y and Al2(MoO4)3 compounds. Furthermore, corrosion resistance of the treated aluminium foil was evaluated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. Our results show that all of the aluminium foils with molybdate-based conversion coatings have much better corrosion resistance than bare aluminium foil. Notably, the sample treated at 40 °C exhibited the best corrosion resistance. The new method is very suitable for continuous processing.

Liang, Chang-Sheng; Lv, Zhong-Fei; Zhu, Ye-Ling; Xu, Shi-Ai; Wang, Hong

2014-01-01

441

Searching for new aluminium chelating agents: a family of hydroxypyrone ligands.  

PubMed

Attention is devoted to the role of chelating agents in the treatment of aluminium related diseases. In fact, in spite of the efforts that have drastically reduced the occurrence of aluminium dialysis diseases, they so far constitute a cause of great medical concern. The use of chelating agents for iron and aluminium in different clinical applications has found increasing attention in the last thirty years. With the aim of designing new chelators, we synthesized a series of kojic acid derivatives containing two kojic units joined by different linkers. A huge advantage of these molecules is that they are cheap and easy to produce. Previous works on complex formation equilibria of a first group of these ligands with iron and aluminium highlighted extremely good pMe values and gave evidence of the ability to scavenge iron from inside cells. On these bases a second set of bis-kojic ligands, whose linkers between the kojic chelating moieties are differentiated both in terms of type and size, has been designed, synthesized and characterized. The aluminium(III) complex formation equilibria studied by potentiometry, electrospray ionization mass spectroscopy (ESI-MS), quantum-mechanical calculations and (1)H NMR spectroscopy are here described and discussed, and the structural characterization of one of these new ligands is presented. The in vivo studies show that these new bis-kojic derivatives induce faster clearance from main organs as compared with the monomeric analog. PMID:24200878

Toso, Leonardo; Crisponi, Guido; Nurchi, Valeria M; Crespo-Alonso, Miriam; Lachowicz, Joanna I; Mansoori, Delara; Arca, Massimiliano; Santos, M Amélia; Marques, Sérgio M; Gano, Lurdes; Niclós-Gutíerrez, Juan; González-Pérez, Josefa M; Domínguez-Martín, Alicia; Choquesillo-Lazarte, Duane; Szewczuk, Zbigniew

2014-01-01

442

Vinyl capped addition polyimides  

NASA Technical Reports Server (NTRS)

Polyimide resins (PMR) are generally useful where high strength and temperature capabilities are required (at temperatures up to about 700 F). Polyimide resins are particularly useful in applications such as jet engine compressor components, for example, blades, vanes, air seals, air splitters, and engine casing parts. Aromatic vinyl capped addition polyimides are obtained by reacting a diamine, an ester of tetracarboxylic acid, and an aromatic vinyl compound. Low void materials with improved oxidative stability when exposed to 700 F air may be fabricated as fiber reinforced high molecular weight capped polyimide composites. The aromatic vinyl capped polyimides are provided with a more aromatic nature and are more thermally stable than highly aliphatic, norbornenyl-type end-capped polyimides employed in PMR resins. The substitution of aromatic vinyl end-caps for norbornenyl end-caps in addition polyimides results in polymers with improved oxidative stability.

Vannucci, Raymond D. (inventor); Malarik, Diane C. (inventor); Delvigs, Peter (inventor)

1991-01-01

443

Generalized Additive Models  

Microsoft Academic Search

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

Trevor Hastie; Robert Tibshirani

1986-01-01

444

Additive Processes for Metals  

Microsoft Academic Search

\\u000a Metals are vital building blocks for MEMS. Pure metals and metal alloys are employed in microsystem design to achieve a wide\\u000a array of functionality. Common examples include electrical conductors, mechanical structures, magnetic elements, thermal conductors,\\u000a optical reflectors, and more. In this chapter, additive processes for metals are discussed in the context of their application\\u000a in MEMS. Particular attention is paid

David P. Arnold; Monika Saumer; Yong-Kyu Yoon

445

Aluminium Foams Fabricated by the PM Route using Nickel-coated Titanium Hydride Powders of Controlled Particle Size  

NASA Astrophysics Data System (ADS)

To establish the effect of reducing the temperature mismatch between the TiH2 decomposition temperature and the aluminium melting point on the foams morphological features and their mechanical compression behavior, a nickel coating on TiH2 powders was used as a hydrogen diffusion barrier and the size of TiH2 powders was controlled to modify the hydrogen evolution temperature. The nickel diffusion barrier was produced by an electroless deposition technique and the hydrogen evolution behavior of coated powders was investigated by thermogravimetrical analysis. The effect of particle size was determined with powders of five particle size fractions along with powders of different particle size obtained from a supplier. Foamable precursors were obtained by hot pressing a mix of aluminium powders with 1 wt.% of TiH2 powders and foams were fabricated at 750 and 800 °C. The foams mechanical strength was investigated by uni-axial compression on foam cylinders with and without outer skin. Coating produced a continuous and homogeneous deposit of 96.5 wt.% nickel and reduced the initial temperature mismatch by approximately 70°C. Additionally, the coating adhesion proved to be good enough to withstand the mixing and compaction processes. Nickel-coated TiH2 powders generated foams with a more homogeneous and reproducible pore structure than foams produced with powders in the as-received and passivated condition. On the other hand, the hydrogen evolution onset of TiH2 shifted towards higher temperatures as the particle size increased. The particle size influenced the foam expansion and the porosity features. Powders of larger particle size produced foams with a more uniform pore distribution and size. Finally, compression tests on skinless foams containing nickel displayed quasi-horizontal energy regimes with longer stroke lengths than the rest, however the final energy absorption efficiencies (above 7.2 kJ·kg-1) were not remarkably increased.

Proa-Flores, Paula Mercedes

446

The role of VuMATE1 expression in aluminium-inducible citrate secretion in rice bean (Vigna umbellata) roots  

PubMed Central

Aluminium (Al)-activated citrate secretion plays an important role in Al resistance in a number of plant species, such as rice bean (Vigna umbellata). This study further characterized the regulation of VuMATE1, an aluminium-activated citrate transporter. Al stress induced VuMATE1 expression, followed by the secretion of citrate. Citrate secretion was specific to Al stress, whereas VuMATE1 expression was not, which could be explained by a combined regulation of VuMATE1 expression and Al-specific activation of VuMATE1 protein. Pre-treatment with a protein translation inhibitor suppressed VuMATE1 expression, indicating that de novo biosynthesis of proteins is required for gene expression. Furthermore, post-treatment with a protein translation inhibitor inhibited citrate secretion, indicating that post-transcriptional regulation of VuMATE1 is critical for citrate secretion. Protein kinase and phosphatase inhibitor studies showed that reversible phosphorylation was important not only for transcriptional regulation of VuMATE1 expression but also for post-translational regulation of VuMATE1 protein activity. These results suggest that citrate secretion is dependent on both transcriptional and post-transcriptional regulation of VuMATE1. Additionally, VuMATE1 promoter–?-glucuronidase fusion lines revealed that VuMATE1 expression was restricted to the root apex and was entirely Al induced, indicating the presence of cis-acting elements regulating root tip-specific and Al-inducible gene expression, which will be an important resource for genetic improvement of plant Al resistance.

Liu, Mei Ya; Chen, Wei Wei; Yang, Jian Li

2013-01-01

447

A comparison of the deformation of magnesium alloys with aluminium and steel in tension, bending and buckling  

Microsoft Academic Search

A comparison was made between high pressure die cast and wrought magnesium alloys and formed mild steel and aluminium in tensile, bending and buckling deformation. It was found that the energy absorption properties of magnesium alloys were particularly good in bending and buckling, absorbing up to 50% more energy than the aluminium and over 10 times more energy than the

Mark Easton; Wei Qian Song; Trevor Abbott

2006-01-01

448

Focused ion beam (FIB) etching to investigate aluminium-coated polymer laminates subjected to heat and moisture loads  

Microsoft Academic Search

Multilayered aluminium-coated polymer laminates are the common barrier envelopes of vacuum insulation panels used as high performance thermal insulation in building applications. These laminates are made of up to ten distinct layers including three aluminium barrier layers applied by vacuum web coating. During their expected lifetime, which is required to last longer than 20 years, they will be subjected to heat

S. Brunner; P. J. Tharian; H. Simmler; K. Ghazi Wakili

2008-01-01

449

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

Microsoft Academic Search

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

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

2009-01-01

450

Solution phase chemical synthesis of nano aluminium particles stabilized in poly(vinylpyrrolidone) and poly(methylmethacrylate) matrices  

NASA Astrophysics Data System (ADS)

The reduction of aluminium trichloride by lithium aluminium hydride in the presence of poly(vinylpyrrolidone) or poly(methylmethacrylate) in mesitylene yielded nano aluminium particles in the matrices of respective polymers. Solution phase synthesis methodology was used successfully to produce composites of various Al/polymer ratios. The composites were charecterized by powder XRD patterns and 27Al-NMR with MAS spectroscopic study. The method was useful to produce up to 10 g of nano aluminium that were pure and stable.The reduction of aluminium trichloride by lithium aluminium hydride in the presence of poly(vinylpyrrolidone) or poly(methylmethacrylate) in mesitylene yielded nano aluminium particles in the matrices of respective polymers. Solution phase synthesis methodology was used successfully to produce composites of various Al/polymer ratios. The composites were charecterized by powder XRD patterns and 27Al-NMR with MAS spectroscopic study. The method was useful to produce up to 10 g of nano aluminium that were pure and stable. Electronic supplementary information (ESI) available: Supplementary figures. See DOI: 10.1039/b9nr00337a

Ghanta, Sekher Reddy; Muralidharan, Krishnamurthi

2010-06-01

451

The friction and wear of Kevlar 49 sliding against aluminium at low velocity under high contact pressures  

Microsoft Academic Search

The friction and wear behaviour of Kevlar 49 sliding against aluminium under large contact pressures at low sliding velocities was examined. Kevlar 49 on aluminium friction is measured using yarns on capstans, and compared with literature results for Kevlar 49 on itself. A modified version of Howell's equation is presented in terms of stresses, ?=a??, to allow finite element modelling

I. F Brown; C. J Burgoyne

1999-01-01

452

Pearlite-like eutectic of ZL 108 aluminium-silicon alloy containing rare-earth elements rapidly solidified by laser  

Microsoft Academic Search

Cast aluminium alloys with eutectic composition have been frequently used in industry owing to their low cost, simple processing and light weight. Their mechanical properties strongly depend on their eutectic microstructure. Such methods as adding elements and rapid solidification have been widely used to refine the eutectic. A lot of work on the eutectic structure in cast aluminium alloys has

H. Jiandong; L. Yongbing; L. Zhang

1990-01-01

453

The application of polycrystalline diamond (PCD) tool materials when drilling and reaming aluminium based alloys including MMC  

Microsoft Academic Search

Following a review of metal matrix composite (MMC) materials and production methods, the paper outlines the development and application of PCD cutting tools. Experimental data are presented for the drilling and single blade reaming of aluminium-silicon alloys containing 7% and 13% silicon and aluminium 2618 MMC alloy reinforced with 15 vol% silicon carbide (SiC) particulate. Though initially aimed only at

R. T. Coelho; S. Yamada; D. K. Aspinwall; M. L. H. Wise

1995-01-01

454

Minimum quantity lubrication drilling of aluminium–silicon alloys in water using diamond-like carbon coated drills  

Microsoft Academic Search

The dry drilling of aluminium alloys (without using cutting fluids) is an environmentally friendly machining process but also an exceedingly difficult task due to aluminium's tendency to adhere to the drills made of conventional materials such as the high-speed steel (HSS). Diamond-like carbon (DLC) coatings improve the dry drilling performance due to their adhesion mitigating properties. In this work, improvements

Sukanta Bhowmick; Ahmet T. Alpas

2008-01-01

455

Quality assessment of gutted wild sea bass ( Dicentrarchus Labrax ) stored in ice, cling film and aluminium foil  

Microsoft Academic Search

The effects of aluminium foil and cling film on microbiological, chemical and sensory changes in wild sea bass (Dicentrarchus labrax) stored at chill temperature (4 °C) were studied. A quality assessment of wild sea bass stored in ice, in boxes without ice, wrapped in aluminium foil (WAF) and wrapped in cling film (WCF) at 4 °C was performed by monitoring sensory quality,

F. Özogul; C. Gökbulut; G. Özyurt; Y. Özogul; M. Dural

2005-01-01

456

The effect of cross-head velocity and length of tube on energy absorption of aluminium tube  

Microsoft Academic Search

The objective of this study is to investigate the effect of variation of the tube length and the crosshead velocity on the amount of energy absorption of aluminium tubes (Al 6061) towards the inversion collapsed mode. The tests were performed on the Aluminium tubes using compression test apparatus according to ASTM E8 standard procedures. Two parameters that are included in

Mohd Suhairil Meon; Hazran Husain; Muhamad Fauzi Othman; Muhammad Fairuz Remeli; Mohd Syahar Mohd Syawal

2011-01-01

457

The influence of nickel–aluminium bronze microstructure and crevice solution on the initiation of crevice corrosion  

Microsoft Academic Search

A new mechanistic model has been established for the chemical and electrochemical mechanisms controlling nickel–aluminium bronze crevice corrosion. The crevice corrosion was initially confined to eutectoid regions with slight attack of the copper rich ?-phase within the ?+?III eutectoid. In the presence of high chloride concentrations, copper and aluminium complexes form and the hydrolysis of these complexes leads to the

J. A. Wharton; K. R. Stokes

2008-01-01

458

Catalytic C-H bond activation at nanoscale Lewis acidic aluminium fluorides: H/D exchange reactions at aromatic and aliphatic hydrocarbons.  

PubMed

Nanoscopic amorphous Lewis acidic aluminium fluorides, such as aluminium chlorofluoride (ACF) and high-surface aluminium fluoride (HS-AlF(3)), are capable of activating C-H bonds of aliphatic hydrocarbons. H/D exchange reactions are catalysed under mild conditions (40?°C). PMID:22125129

Prechtl, Martin H G; Teltewskoi, Michael; Dimitrov, Anton; Kemnitz, Erhard; Braun, Thomas

2011-12-16

459

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

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

S. C. Mok

2011-01-01

460

Preparation and stabilization of aluminium trifluoroacetate fluoride sols for optical coatings.  

PubMed

For the first time, aluminium fluorides in liquid phase are available for optical applications. By modifying the conditions of the fluorolytic sol-gel synthesis of aluminium fluorides transparent sols with low viscosities were obtained. These sols consist mainly of small oligomeric or cluster units of aluminium fluoride which are not measurable by DLS, WAXS, SAXS and show unusual narrow signals in solid state NMR. Isolated particles with diameters up to five nanometers can be identified by TEM measurements and allow the use of their sols in optical and anti reflecting coatings. The sol particles were modified by trifluoroacetic acid to prevent agglomeration, and as a result, the obtained xerogels can be re-dispersed transparently in organic solvents. PMID:22885847

Fritz, C; Scholz, G; Feist, M; Kemnitz, E

2012-10-01

461

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

PubMed

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

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

2012-06-14

462

Evaluation Of Four Welding Arc Processes Applied To 6061 Aluminium Alloy  

NASA Astrophysics Data System (ADS)

At a time when greenhouse gas emissions must be reduced, the use of the aluminium alloys is expanding, in particular in the transportation industry. In order to extend the possibilities of aluminium assembly design, new Metal Inert Gas (MIG) welding processes have been conceived. They work at lower temperatures than usual arc processes (classic MIG or Tungsten Inert Gas). This study compares four arc welding processes, applied to the 6061 aluminium alloy. These four weld processes have been studied through the metallurgical analysis of the weld beads. Metallography, micro-hardness testings, X Ray radiography have been carried out on the produced weld beads. The processes are classified according to the quality of the beads like geometry of beads, size of the heat affected zone and presence of defects.

Benoit, A.; Paillard, P.; Baudin, T.; Jobez, S.; Castagné, J.-F.

2011-01-01

463

3.OA Addition Patterns  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Below is a table showing addition of numbers from $1$ through $5$. In each column and each row of the table, even and odd numbers alternate. Explain wh...

464

Oil additive process  

SciTech Connect

This patent describes a method of making an additive comprising: (a) adding 2 parts by volume of 3% sodium hypochlorite to 45 parts by volume of diesel oil fuel to form a sulphur free fuel, (b) removing all water and foreign matter formed by the sodium hypochlorite, (c) blending 30 parts by volume of 24% lead naphthanate with 15 parts by volume of the sulphur free fuel, 15 parts by volume of light-weight material oil to form a blended mixture, and (d) heating the blended mixture slowly and uniformly to 152F.

Bishop, H.

1988-10-18

465

Appendix: Additional Contributions  

NASA Astrophysics Data System (ADS)

The number of contributions to the Symposium was so high that only the review and invited talks have found place, in the form of articles, in this volume. This Appendix lists all these additional contributions (oral and posters) which are not present as articles. The abstracts of all contributions were published in a booklet produced by the Local Organizing Committee and are available at the SAO/NASA Astrophysics Data System (ADS). More information on these contributions (PowerPoint presentations and/or articles) have been made public in the Internet web site of the conference (http://cab.inta-csic.es/molecular_universe/).

2011-12-01

466

Aluminium induced oxidative stress results in decreased mitochondrial biogenesis via modulation of PGC-1? expression.  

PubMed

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 (10mg/kgb.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. PMID:24084166

Sharma, Deep Raj; Sunkaria, Aditya; Wani, Willayat Yousuf; Sharma, Reeta Kumari; Kandimalla, Ramesh J L; Bal, Amanjit; Gill, Kiran Dip

2013-12-01

467

Effects of combined additions of Sr and AlTiB grain refiners in hypoeutectic Al–Si foundry alloys  

Microsoft Academic Search

Strontium is the most widely used and a very effective element for modifying the morphology of eutectic silicon, while Ti and B are commonly present in the commercial grain refiners used for Al–Si alloys. Systematic studies on the effects of combined additions of Sr and different AlTiB grain refiners on the Al+Si eutectic and primary aluminium solidification have been performed.

L. Lu; A. K. Dahle

2006-01-01

468

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

NASA Astrophysics Data System (ADS)

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.

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

2012-04-01

469

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

Microsoft Academic Search

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-,

D. D. Macdonald; C. English

1990-01-01

470

A ToF-SIMS study of linseed oil bonded to mercapto silane treated aluminium  

NASA Astrophysics Data System (ADS)

ToF-SIMS has been used to analyse an aluminium surface treated with a vegetable oil using a mercapto silane as a coupling agent between the aluminium substrate and the vegetable oil. The coupling between the vegetable oil and the mercapto silane was obtained through a photoinduced thiol-ene reaction using UV-radiation. The ToF-SIMS results show that the desired thiol-ene reaction has taken place between the unsaturated parts of the vegetable oil and the thiol groups of the mercapto silane via the thiol-ene reaction forming a surface film.

Bexell, U.; Olsson, M.; Sundell, P.-E.; Johansson, M.; Carlsson, P.; Hellsing, M.

2004-06-01

471

Fibre-optic titrations-IV Direct complexometric titration of aluminium(III) with DCTA.  

PubMed

The end-point of the direct complexometric titration of Al(3+) in pH 4.6 solution can be determined by monitoring the fluorescence intensity of the aluminium-morin complex, by use of a bifurcated fibre-optic light guide. The method allows the determination of aluminium in the 1-800 ppm range with good precision. The procedure is applicable even when the solutions are strongly coloured or turbid, but because of the slow complexation kinetics requires a titration time of about 20 min. PMID:18964217

Wolfbeis, O S; Schaffar, B P; Chalmers, R A

1986-11-01

472

Fatigue behaviour of graphite and interpenetrating graphite–aluminium composite up to 10 9 load cycles  

Microsoft Academic Search

Fatigue behaviour of polycrystalline, isotropic graphite FU2590 (porosity 13vol%) and of FU2590 infiltrated with the aluminium alloy AlSi7Mg (FU2590\\/AlSi7Mg) is investigated. The interpenetrating graphite–aluminium composite is produced by squeeze casting infiltration, where the open porosity of FU2590 (10–11vol%) is infiltrated with AlSi7Mg. Fully reversed bending fatigue tests at cycling frequency 25Hz and fully reversed tension–compression experiments at 20kHz are performed.

H. Mayer; M. Papakyriacou

2006-01-01

473

An aluminium nitride light-emitting diode with a wavelength of 210 nanometres.  

PubMed

Compact high-efficiency ultraviolet solid-state light sources--such as light-emitting diodes (LEDs) and laser diodes--are of considerable technological interest as alternatives to large, toxic, low-efficiency gas lasers and mercury lamps. Microelectronic fabrication technologies and the environmental sciences both require light sources with shorter emission wavelengths: the former for improved resolution in photolithography and the latter for sensors that can detect minute hazardous particles. In addition, ultraviolet solid-state light sources are also attracting attention for potential applications in high-density optical data storage, biomedical research, water and air purification, and sterilization. Wide-bandgap materials, such as diamond and III-V nitride semiconductors (GaN, AlGaN and AlN; refs 3-10), are potential materials for ultraviolet LEDs and laser diodes, but suffer from difficulties in controlling electrical conduction. Here we report the successful control of both n-type and p-type doping in aluminium nitride (AlN), which has a very wide direct bandgap of 6 eV. This doping strategy allows us to develop an AlN PIN (p-type/intrinsic/n-type) homojunction LED with an emission wavelength of 210 nm, which is the shortest reported to date for any kind of LED. The emission is attributed to an exciton transition, and represents an important step towards achieving exciton-related light-emitting devices as well as replacing gas light sources with solid-state light sources. PMID:16710416

Taniyasu, Yoshitaka; Kasu, Makoto; Makimoto, Toshiki

2006-05-18

474

The genotoxic, hepatotoxic, nephrotoxic, haematotoxic and histopathological effects in rats after aluminium chronic intoxication.  

PubMed

Aluminium (Al) is used in water purification and is also present in several manufactured foods and medicines. Al is known to induce a broad range of physiological, biochemical and behavioural dysfunctions in laboratory animals and humans. This investigation was carried out to investigate the effects of subchronic exposure to Al (as AlCl?) in rats. Sprague-Dawley rats were randomly separated into two groups. Group 1 rats treated with sodium chloride served as the control, group 2 rats were treated with Al (as AlCl?, 5 mg/kg body weight) intraperitonally for 10 weeks. Animals were killed and blood samples were analyzed for blood serum alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) enzyme activities and creatinine, urea (U) and uric acid (UA) levels for evaluating hepatotoxicity and nephrotoxicity. Blood parameters including red blood cells (RBCs), haemoglobin (Hb) concentration, haematocrit (Ht), platelets (PLTs) and white blood cells (WBCs) were compared between control and experimental group to assess haematoxicity. In order to determine the genotoxicity, the number of micronucleated hepatocytes (MNHEPs) was counted in isolated hepatocytes. In addition, histological alterations in liver and kidney samples were investigated. After exposure with Al, the enzymatic activities of ALP, AST, ALT and LDH, and the levels of U and UA significantly increased. RBC, WBC, PLT, Hb and Ht revealed significant decreases in experimental group compared to the control. AlCl? caused a significant increase in MNHEPs. Furthermore, severe pathological damages were established in both liver and kidney samples. Subchronic exposure to low doses of Al can produce serious dysfunctions in rat blood, liver and kidney, and exposure to this metal can result in greater damages. PMID:22421584

Geyikoglu, Fatime; Türkez, Hasan; Bakir, Tülay Ozhan; Cicek, Mustafa

2013-10-01

475

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

SciTech Connect

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)

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

2013-07-31

476

Performance Boosting Additive  

NASA Technical Reports Server (NTRS)

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.

1999-01-01

477

New addition curing polyimides  

NASA Technical Reports Server (NTRS)

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.

Frimer, Aryeh A.; Cavano, Paul

1991-01-01

478

Sewage sludge additive  

NASA Technical Reports Server (NTRS)

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.

Kalvinskas, J. J.; Mueller, W. A.; Ingham, J. D. (inventors)

1980-01-01

479

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

Microsoft Academic Search

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)

T. Sasimurugan; K. Palanikumar

2011-01-01

480

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

Microsoft Academic Search

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

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

2012-01-01

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