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1

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

2

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

3

Phase composition of aluminium oxides promoted by Cr, Cu and Ni additives  

Microsoft Academic Search

X-ray diffraction analysis of aluminium oxides promoted by Cr3+, Cu2+ and Ni2+ additives has been carried out in a high-temperature X-ray chamber. It has been revealed that at T=823–1473 K in inert media, solid solutions are formed and transformation to ?-Al2O3 takes place differently. Mineralizing action of Cu cations is suggested to be due to the decomposition of Cu2+-containing aluminate

E. M. Moroz; O. A. Kirichenko; A. V. Ushakov; E. A. Levitskii

1985-01-01

4

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

E-print Network

and vanadium solubility. Alizée P. Lehoux1# , Cindy L. Lockwood1 , William M. Mayes2 , Douglas I. Stewart3, contaminated soils, gypsum, toxic trace elements, arsenic, vanadium, aluminium, organic matter leaching, p

Burke, Ian

5

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

6

Aluminium levels in Italian diets and in selected foods from aluminium utensils.  

PubMed

In Italy, data on aluminium concentration in food items are scarce although aluminium containers are widely used to cook, to freeze or to wrap foods (foil) and it is known that aluminium can migrate from containers to foods. Therefore, an experimental study was carried out to quantify aluminium exposure from ingestion of actual total diets and from migration from containers to foods in conditions representative of the actual use. Samples of 24 h diets were collected, homogenized, lyophilized and the amount of aluminium was determined by atomic absorption spectrometry. The aluminium concentrations ranged from 1.0 to 2.1 mg/kg of food; the intake of aluminium ranged from 2.5 to 6.3 mg/day. The amount of aluminium migrating from aluminium cookware was determined by cooking various representative foods in aluminium and in glass or stainless steel containers. From comparison of the results, the increase in aluminium because of migration from cookware was relatively low, with the highest release into acidic and salty foods. The daily intake of aluminium even if all the foods were prepared and stored in aluminium containers would be approximately 6 mg/day, a very low value compared with the Provisional Tolerable Weekly Intake of 7 mg/kg body weight (equivalent to 60 mg/day for an adult man) established by the Joint FAO/WHO Expert Committee on Food Additives. PMID:8885317

Gramiccioni, L; Ingrao, G; Milana, M R; Santaroni, P; Tomassi, G

1996-10-01

7

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

8

A preliminary study of dietary aluminium intake and risk of Alzheimer's disease  

Microsoft Academic Search

Background: epidemiological studies of Alzheimer's disease and aluminium intake have focused on aluminium in drinking water. There have been no studies investigating the relation between the disease and the consumption of foods containing large amounts of aluminium additives. Objectives: to conduct a pilot study to determine whether dietary intake of aluminium additives differs in individuals with and without Alzheimer's disease.

MARY A. M. ROGERS; D AVID G. SIMON

1999-01-01

9

Microbial interactions with aluminium  

Microsoft Academic Search

Although aluminium is the most abundant metal in the Earth's crust, it lacks biological functions and shows a low bioavailability. Acid rain, however, solubilizes aluminium to toxic levels. Most research on the biological effects of aluminium has been centred on the analysis of aluminium-tolerant plants as well as its possible relationship with neurological disorders in humans. Also, several studies have

Rogelio Garciduefias Pifia; Carlos Cervantes

1996-01-01

10

Flocculation of slaughterhouse effluents with aluminium salts  

Microsoft Academic Search

The use of aluminium salts to remove suspended solids and a proportion of the soluble material from slaughterhouse effluents was examined. Acidification prior to the addition of 40 mg\\/1 aluminium is recommended so that the final pH is approximately 5.0. Removal efficiency is greatest at a pH just above the average isoelectric point of the effluent proteins.

J. M. Russell; R. N. Cooper

1981-01-01

11

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. PMID:1954151

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

1991-01-01

12

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

13

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 ...

Mrs. Hoffmann

2011-08-09

14

Effect of aluminium additions on wettability and intermetallic compound (IMC) growth of lead free Sn (2 wt. % Ag, 5 wt. % Bi) soldered joints  

NASA Astrophysics Data System (ADS)

The effect of a trace Al addition (0, 0.01, 0.05 and 0.1 wt. %) in the Sn-2Ag-5Bi solder alloy on wettability and intermetallic compound (IMC) formation of the alloy was investigated. The interface between the solder and a Cu(17 ?m)/Ni(4 ?m)/Au (0.02 ?m) under bump metallized (UBM) substrate was studied. The microstructure of the bulk solder and the interface of the soldered joints was observed in a scanning electron microscope (SEM), and the thickness of the interface reaction layers was estimated. Various IMC phases were identified by energy dispersive spectroscopy (EDS) and by the electron probe micro analyzer (EPMA). The experimental results indicated that the addition of 0.01 wt. % Al in the Sn-2Ag-5Bi solder alloy significantly improved the wettability of the solder more than the other Al additions did. The IMC layer between the bulk Sn-2Ag5Bi-0.01Al solder and the Cu/Ni/Au UBM substrate was almost uniform and thinner than those between the solders containing 0, 0.05, and 0.1 wt. % Al and their respective Cu/Ni/Au UBM substrates. Furthermore, the growth rate of the IMC layer between the Sn-2Ag-5Bi-0.01Al solder and Cu/Ni/Au UBM after 1 to 10 reflow times was lower than that of the IMC layer between the Sn-2Ag-5Bi solder and Cu/Ni/Au UBM. The IMCs in the solder joint interface (e.g., Ni3Sn4) of the Sn-2Ag-5Bi-0.01Al solder were well distributed near the Bi and fine Ag3Sn. The addition of 0.01 wt. % Al in the Sn-2Ag-5Bi solder yielded the best wetting properties for the solder and the minimum growth rate of the IMCs because it increased the nucleation rate of Ag3Sn and uniformly segregated the Bi phase.

Lee, Hee Yul; Sharma, Ashutosh; Kee, Se Ho; Lee, Young Woo; Moon, Jung Tak; Jung, Jae Pil

2014-09-01

15

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

Microsoft Academic Search

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

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

2000-01-01

16

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

17

Grain refinement of AA333 aluminium cast alloy by Al–Ti granulated flux  

Microsoft Academic Search

Addition of grain refiner is an option to obtain higher mechanical properties of aluminium cast alloy. Grain refiner will react with molten aluminium and will form nucleant particles that initiate solidification. Therefore, the grain refiner will also be useful to control the solidification processes to reduce shrinkage formation. This study evaluated grain refinement in AA333 aluminium alloys by using Al–Ti

Bondan T. Sofyan; Daniel J. Kharistal; Lukfawan Trijati; Kaspar Purba; Ragil E. Susanto

2010-01-01

18

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.

2013-07-17

19

Aluminium phosphide poisoning.  

PubMed

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

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

2006-01-01

20

Aluminium in Commercial Vehicles  

NSDL National Science Digital Library

This manual created by the European Aluminium Association is a comprehensive compilation of aluminum use in commercial applications. Discussed are application, design, joining, treatment, cleaning, repair, and various methods of processing aluminum. Although this report is of particular interest to design engineers, process engineers, repair managers and maintenance managers, it’s also very useful to anyone interested in aluminum development and use in transportation.

2013-07-10

21

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

22

Lotus: aluminium extrusions and adhesives  

Microsoft Academic Search

Spotlights the design and development of an aluminium chassis for the new Lotus Elise. Highlights the benefits of using aluminium extrusions and the reasons for choosing bonding as opposed to welding. Describes the assembly process and how the maintenance and repair drawback of a bonded design can be overcome. Notes that the largest proportion of Lotus’ sales actually come from

Anna Kochan

1996-01-01

23

Aluminium at terapascal pressures.  

PubMed

Studying materials at terapascal (TPa) pressures will provide insights into the deep interiors of large planets and chemistry under extreme conditions. The equation of state of aluminium is of interest because it is used as a standard material in shock-wave experiments and because it is a typical sp-bonded metal. Here we use density-functional-theory methods and a random-searching approach to predict stable structures of aluminium at multiterapascal pressures, finding that the low-pressure close-packed structures transform to more open structures above 3.2 TPa (nearly ten times the pressure at the centre of the Earth), with an incommensurate host-guest structure being stable over a wide range of pressures and temperatures. We show that the high-pressure phases may be described by a two-component model consisting of positive ions and interstitial electron 'blobs', and propose that such structures are common in sp-bonded materials up to multiterapascal pressures. PMID:20622863

Pickard, Chris J; Needs, R J

2010-08-01

24

Bending of square aluminium extrusions with aluminium foam filler  

Microsoft Academic Search

Summary An experimental programme consisting of 24 tests was carried out to study the three-point-bending behavior of square AA6060 aluminium extrusions filled with aluminium foam under quasi-static loading conditions. The outer cross section width and span of the beams were kept constant at 80 mm and 800 mm, respectively. The main parameters investigated were the foam density, the extrusion wall

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

2000-01-01

25

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

26

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

27

Aluminium Involvement in Neurotoxicity  

PubMed Central

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

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

2014-01-01

28

Aluminium concentrations in the brain and bone of rats fed citric acid, aluminium citrate or aluminium hydroxide.  

PubMed

Male Sprague-Dawley rats were treated daily by gastric intubation (6 days/wk) with 100 mg aluminium/kg body weight in the form of aluminium hydroxide (9 wk) or aluminium citrate (4 wk), with citric acid (4 wk) or with tap-water (control, 9 wk). Young adult and aged Wistar rats were treated with 100 mg aluminium/kg body weight as aluminium hydroxide or with carboxymethylcellulose (vehicle controls). The cerebral cortex, hippocampus, cerebellum and samples of bone from each rat were analysed for aluminium, after digestion with nitric acid, using graphite furnace atomic absorption spectroscopy. The mean aluminium concentrations detected in the control Sprague-Dawley rats were 0.013-0.022 microgram/g wet weight in the various brain regions and 0.355 microgram/g in the bone. No significant increase in tissue aluminium concentrations was observed in Sprague-Dawley or Wistar rats after treatment with aluminium hydroxide. However the rats treated with aluminium citrate showed significantly increased concentrations of aluminium in all the brain regions studied (0.057-0.121 microgram A1/g) and in the bone (12.9 micrograms A1/g). Elevated aluminium concentrations in the cerebral cortex and bone were also observed in the animals fed citric acid suggesting possible absorption of the citrate chelate presumably formed with the traces of aluminium present in the diet. PMID:6539288

Slanina, P; Falkeborn, Y; Frech, W; Cedergren, A

1984-05-01

29

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

30

Modelling of plastic anisotropy in heat-treated aluminium extrusions  

Microsoft Academic Search

Uniaxial tensile tests have been conducted for the commercial aluminium alloy AA7108 in different tempers. In addition, pure bending tests were performed for temper W (20min). The influence of heat-treatment on plastic anisotropy in strength, plastic flow and strain hardening has been investigated by performing tests with three loading directions with respect to the extrusion axis. The experimental data have

O.-G. Lademo; O. S. Hopperstad; K. A. Malo; K. O. Pedersen

2002-01-01

31

Heat treatments in aluminium-lithium composites extrusion  

Microsoft Academic Search

Aluminium-matrix composites have attracted considerable academic and industrial attention in recent years where modulus increases of 100% and strength increases of 60% have been reported. The addition of lithium further enhances most of these properties through the precipition of the coherent phase, ??. Their widespread usage is limited by the low room temperature ductility, although there remains scope for superplasticity

M. J. Tan; L. H. Koh; K. A. Khor; Y. Murakoshi; T. Sano

1995-01-01

32

Reuse of steel and aluminium without melting  

E-print Network

...................................................................................... 30  2.3.1   Theories  of  bond  formation.............................................................................................. 31  2.3.2   Aluminium  chip  extrusion... between the substrate aluminium e Micro-extrusion channel width pex Pressure required to micro-extrude aluminium through oxide layer cracks Diffusion parameters X (t) Diffusion distance (process time) D Diffusion coefficient ! " ! ? " ...

Cooper, Daniel

2014-01-07

33

Aluminium phosphide-induced leukopenia.  

PubMed

Acute intoxication from the pesticide aluminium phosphide is a relatively rare, life-threatening condition in which cardiovascular decompensation is the most feared problem. We report the case of a patient exposed to aluminium phosphide-liberated phosphine gas. It resulted in the development of a gastroenteritis-like syndrome accompanied by severe reduction in white blood cell numbers as an early and prominent manifestation. By affecting important physiological processes such as mitochondrial function and reactive oxygen species homeostasis, phosphine could cause severe toxicity. After presenting the characteristics of certain leucocyte subpopulations we provide the current molecular understanding of the observed leukopenia which in part seems paradoxical. PMID:24172776

Ntelios, Dimitrios; Mandros, Charalampos; Potolidis, Evangelos; Fanourgiakis, Panagiotis

2013-01-01

34

Controlled Bending of Aluminium Extrusions  

Microsoft Academic Search

This paper presents a control circuit for a stretch bending process of aluminium extrusions. The control strategy is derived from an analytical model which accounts for the process parameters allows the calculation of springback. The first component of the control circuit is the definition of suitable target and control values, for the later of which tensile stresses have been qualified.

M. Geiger; A. Sprenger

1998-01-01

35

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

36

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

37

Thermal stability of octadecyltrichlorosilane self-assembled on a polycrystalline aluminium surface  

Microsoft Academic Search

In search for a good boundary lubricant additive for aluminium substrates we investigate the molecular disorder retained in a monolayer self-assembled on an aluminium surface subjected to thermal cycling. Our target molecule is octadecyltrichlorosilane (C18H37SiCl3, OTS) but we also study octadecanoic acid (C17H35COOH) to explore the effect of changing the molecular head group. The two molecules have the same alkyl

Om Prakash Khatri; S. K. Biswas

2004-01-01

38

Synthesis of yttrium aluminium garnet by the gel entrapment technique using hexamine  

Microsoft Academic Search

A novel technique has been developed for the preparation of yttrium aluminium garnet (YAG), represented by the chemical formula Y3Al5O12, by achieving the homogeneous precipitation of the constituent metal hydroxides from the stoichiometric mixture of the metal nitrate solution by the addition of hexamethylene tetramine solution. Aluminium ions form a gel at pH 4, entrapping all the liquid, followed by

R. V. Kamat; K. T. Pillai; V. N. Vaidya; D. D. Sood

1996-01-01

39

Aluminium in Allergies and Allergen immunotherapy.  

PubMed

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

Jensen-Jarolim, Erika

2015-01-01

40

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

Microsoft Academic Search

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

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

1972-01-01

41

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

42

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

43

Melt spun aluminium alloys for moulding optics  

NASA Astrophysics Data System (ADS)

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

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

2013-09-01

44

Mould filling analysis of aluminium extrusion dies  

Microsoft Academic Search

During trial pressings of an aluminium extrusion the shape of the first extrudate (nose piece) tells the correctors how to change the die geometry to obtain an acceptable product. In this paper the initial filling of an aluminium extrusion die is analyzed with the objective to predict the shape of the nose piece. The calculation domain is discretized using P1+P1

A. J. Koopman; H. J. M. Geijselaers; J. Huétink; F. Barlat; Y. H. Moon; M. G. Lee

2010-01-01

45

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

46

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

47

Neuroprotective effect of carvedilol against aluminium induced toxicity: possible behavioral and biochemical alterations in rats.  

PubMed

Aluminium, is a trace element available in the Earth's crust naturally and has a toxic potential for humans. It has been suggested as a contributing factor in the pathogenesis of Alzheimer's disease. ?-Adrenoceptor blocking agents (?-blockers) have been established as therapeutics for the treatment of patients with hypertension, ischemic heart diseases, chronic heart failure, arrhythmias and glaucoma. Over the years, however, ?-blockers have been associated with an incidence, albeit low, of central nervous system (CNS) side effects. In addition, noradrenergic receptors play a modulatory role in many nerve functions, including vigilance, attention, reward, learning and memory. Therefore, the present study has been designed to explore the possible role of carvedilol, an adrenergic antagonist against aluminium chloride-induced neurotoxicity in rats. Aluminium chloride (100 mg/kg) was administered daily for six weeks that significantly increased cognitive dysfunction in the Morris water maze and oxidative damage as indicated by a rise in lipid peroxidation and nitrite concentration and depleted reduced glutathione, superoxide dismutase, catalase and glutathione S-transferase activity compared to sham treatment. Chronic aluminium chloride treatment also significantly increased acetylcholinesterase activity and the aluminium concentration in brain compared to sham. Chronic administration of carvedilol (2.5 and 5 mg/kg, po) daily to rats for a period of 6 weeks significantly improved the memory performance tasks of rats in the Morris water maze test, attenuated oxidative stress (reduced lipid peroxidation, nitrite concentration and restored reduced glutathione, superoxide dismutase, catalase and glutathione S-transferase activity), decreased acetylcholinesterase activity and aluminium concentration in aluminium-treated rats compared to control rats (p < 0.05). Results of this study demonstrated the neuroprotective potential of carvedilol in aluminium chloride-induced cognitive dysfunction and oxidative damage. PMID:22001979

Kumar, Anil; Prakash, Atish; Dogra, Samrita

2011-01-01

48

Effects of aluminium on electrical and mechanical properties of frog atrial muscle.  

PubMed Central

1. The effects of aluminium on membrane ionic currents were studied in single cardiac myocytes. Most of the work was done on frog atrial cells, but some experiments were also carried out on single cells isolated from rabbit ventricles and atria. 2. The effects of aluminium on the force of contraction of frog atrial trabeculae were also investigated. 3. Aluminium was prepared from AlCl3 as a stock 0.5 M solution which has a pH of 3.5. Before each experiment, this solution was added to the control solution, to give a final concentration of 20-100 micrograms ml-1 aluminium (0.75-3.75 mM AlCl3). The solutions were brought to a pH of 7.4 or 7.6. at which they consist of a mixture of amorphous aluminium hydroxides and a very small amount of soluble ionic aluminium complexes: free aluminium cations (less than 10 pM), aluminohydroxide anions (less than 8 microM). The addition of this suspension reduced the peak inward calcium currents in single rabbit atrial and ventricular cells and in frog atrial cells. In the latter, the peak current was reduced (at + 10 mV) to 45% of control (mean of 9 cells). This effect was reversible upon washout, and was obtained at all membrane potentials, with no shift of the calcium current voltage relationship along the voltage axis. 4. Aluminium also reduced the time-dependent potassium current IK. This reduction was observed at all membrane potentials. For example, at + 10 mV, the mean reduction of IK (n = 9) was to 69% of the control amplitude. This effect, which was very difficult to reverse, was not due to IK rundown.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2015425

Meiri, H.; Shimoni, Y.

1991-01-01

49

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. PMID:24757505

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

2014-01-01

50

Aluminium in biological environments: a computational approach.  

PubMed

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

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

2014-01-01

51

Blood and urine concentrations of aluminium among workers exposed to aluminium flake powders.  

PubMed Central

In a group of workers exposed to aluminium flake powders, blood and urine concentrations of aluminium were assessed before and after vacation. Another group was investigated after retirement. Workers currently exposed to aluminium flake powders had urinary concentrations of the metal 80-90 times higher than those in occupationally non-exposed referents. The calculated half life for concentrations of aluminium in urine was five to six weeks based on four to five weeks of non-exposure. Among the retired workers the half lives varied from less than one up to eight years and were related to the number of years since retirement. These results indicate that aluminium is retained and stored in several compartments of the body and eliminated from these compartments at different rates. PMID:1998604

Ljunggren, K G; Lidums, V; Sjögren, B

1991-01-01

52

Microstructure and superplasticity in a stir-cast SiCp/2024 aluminium composite  

SciTech Connect

Aluminium matrix composites reinforced with ceramic whiskers or particles have a high specific strength and modulus in addition to good wear resistance and heat resistance. They have shown considerable promise in structural applications, but one of the main drawbacks of the composite is the ductility, which leads to the poor formability, and thus limits their applications. Superplastic forming is a viable technique that is used to solve this problem. A number of aluminium base composites can exhibit superplasticity. Until now, almost all of the composites in superplastic studies were prepared by the powder metallurgy (PM) method. This method causes the composites to have very fine grains (about 1 [mu]m) and fewer microstructural defects; as a result, they exhibited high strain rate superplasticity. Studies on the superplasticity in ingot metallurgy (IM) aluminium matrix composites are rare, but are equally important. Because IM is a low cost method of preparing aluminium matrix composites, it will play an increasingly more important role in the future applications of the composites. In this work the authors investigated the microstructure and superplasticity of a IM 2024 aluminium matrix composite, reinforced with silicon carbide particles (SiCp/2024). They thermomechanically treated the composite by hot forging and extrusion, obtained a superplastic elongation of 685% at an initial strain rate of 5 [times] 10[sup [minus]4]s[sup [minus]1], with a 788K temperature. They also observed and analyzed the microstructure of this composite.

Wei Zheng; Zhang Baoliang; Wang Yanwen (Beijing Research Inst. of Mechanical and Electrical Technology (China))

1994-06-01

53

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

54

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

PubMed

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

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

2006-10-01

55

Aluminium-induced imbalance in oxidant and antioxidant determinants in brain regions of female rats: protection by centrophenoxine.  

PubMed

The present study was carried out to investigate the potential of centrophenoxine in modulating aluminium-induced neurotoxicity. Female Sprague Dawley rats were administered aluminium chloride orally (40 mg/kg b.w./day) for a period of 8 weeks. At the end of respective treatment, various markers of oxidative stress were determined in four different regions of brain: cerebrum cerebellum, medulla oblongata, and hypothalamus. Lipid peroxidation assay was also carried out using standard techniques. Simultaneously, the centrophenoxine group (100 mg/kg b.w./day) for 6 weeks was also run long to understand the role in ameliorating oxidative damage. A significant decrease in the activities of superoxide dismutase and catalase was noticed in all the four regions, the most significant being in the hypothalamus (0.603 +/- .06) and cerebrum (0.038 +/- .01). Due to aluminium toxicity, peroxidation of lipids was also found to be elevated in cerebrum (0.424 +/- .03), cerebellum (0.341 +/- .03), hypothalamus (1.018 +/- .007), and medulla oblongata (0.304 +/- .05). However, posttreatment with centrophenoxine significantly elevated the superoxide and catalase activities in different regions. In addition, lipid peroxidation status of membranes was significantly reduced after centrophenoxine posttreatment to aluminium-exposed animals. Centrophenoxine has proved to be beneficial in combating the damage caused by aluminium toxicity. However, further research is needed to have a better understanding of the molecular basis of aluminium-induced oxidative damage. In addition, the different aspects of centrophenoxine need to be unmasked. PMID:20021037

Nehru, Bimla; Bhalla, Punita

2006-01-01

56

Zinc sulphate and vitamin E alleviate reproductive toxicity caused by aluminium sulphate in male albino rats.  

PubMed

This study was designed to investigate the reproductive toxicity of aluminium sulphate and the therapeutic effects of administration of zinc sulphate and vitamin E individually or in combination against the toxic effect caused by aluminium (Al) in male albino rats. The animals were divided into five groups: group 1 received distilled water and served as control; group 2 received only aluminium sulphate (50 mg/kg body weight (b.w.)); group 3 received aluminium sulphate (50 mg/kg b.w.) plus zinc sulphate (50 mg/kg b.w.); group 4 received aluminium sulphate (50 mg/kg b.w.) and vitamin E (15 mg/kg b.w.); group 5 received aluminium sulphate plus a combination of zinc sulphate and vitamin E in similar doses as above. Doses were administered orally once daily for 45 consecutive days. The results revealed that aluminium sulphate induced significant decrease in body weight gain and testis weight and significant increase in Al level in both serum and testes of male rats. Biochemical analysis showed significant decrease in serum total protein and phospholipids levels, while serum total lipid was significantly elevated post Al treatment. In addition, significant decrease in total protein, phospholipids and cholesterol levels in the testes of Al-treated rats was recorded. The data also showed significant decrease in the levels of serum testosterone, leutinizing hormone and follicle stimulating hormone and significant increase in the level of serum prolactin in Al-intoxicated rats. Moreover, histological examination showed that aluminium sulphate caused apparent alterations in the testicular structure of the treated animals. Treatment with zinc sulphate and vitamin E individually or in combination ameliorated the harmful effects of Al, which was proved histopathologically by the noticeable improvement in the testicular tissues. We can conclude that the tested dose of aluminium sulphate induced toxic effect on the reproductive system of male albino rats and the treatment with zinc sulphate and/or vitamin E alleviated these toxic effects. In some cases, vitamin E exerted a more potent effect, while in other cases, the more potent effect is related to zinc sulphate and the combination of both at most of the recorded data. PMID:23282999

Rawi, Sayed M; Seif Al Nassr, Fatma M

2015-03-01

57

Crash behaviour of thin-walled aluminium members  

Microsoft Academic Search

In order to assess the crashworthiness of aluminium extrusions, a research programme was carried out in co-operation with the aluminium industry in Norway. The main objective was to study the behaviour of aluminium extrusions under axial loading conditions and to give experimental data for validation of a numerical model in the computer code LS-DYNA. In order to increase the energy

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

1998-01-01

58

CAD implementation of design rules for aluminium extrusion dies  

Microsoft Academic Search

Aluminium extrusion is an industrial forming process that is used to produce long profiles of a constant cross-section. This cross-section is shaped by the opening in a steel tool known as the die. The understanding of the mechanics of the aluminium extrusion process is still limited. The flow of aluminium within the die is governed by tribomechanical and rate- and

Ouwerkerk van Gijs

2009-01-01

59

The Microstructure of Mechanically Alloyed Nanocrystalline Aluminium-Magnesium  

E-print Network

The Microstructure of Mechanically Alloyed Nanocrystalline Aluminium-Magnesium Jen Gubicza1 analysis. Magnesium gradually goes into solid solution during ball milling and after 3 h almost all. Experimental A series of aluminium-magnesium samples were prepared from high purity aluminium (99.9%) powder

Gubicza, Jenõ

60

Hard coatings produced by PACVD applied to aluminium die casting  

Microsoft Academic Search

The advantages of using different types of hard coatings in the field of aluminium die casting have been demonstrated in several publications. Hard coatings can protect the steel surface of casting tools from erosion of liquid aluminium and improve the resistance against thermal cracking. The coatings are also expected to prevent the aluminium from soldering onto the tool surface. Lifetime

D. Heim; F. Holler; C. Mitterer

1999-01-01

61

Characterization of anodized and sealed aluminium by EIS  

Microsoft Academic Search

Anodized and sealed aluminium samples exposed to different atmospheres for up to three years have been studied by means of electrochemical impedance spectroscopy (EIS). EIS was used to obtain detailed information concerning the electrochemical properties of the porous and barrier layer of anodized aluminium. An equivalent circuit that reproduces the a.c. impedance results of porous aluminium oxide films is proposed.

J. J Suay; E Giménez; T Rodr??guez; K Habbib; J. J Saura

2003-01-01

62

Factors which Affect the Gelling Characteristics of Aluminium Soaps  

Microsoft Academic Search

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

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

1950-01-01

63

Production of aluminium matrix composite components using conventional PM technology  

Microsoft Academic Search

The machining difficulties and processing costs related to particle reinforced aluminium matrix composites have limited the application range of these advanced materials. The present investigation deals with the production of net shape SiC particle reinforced AA6061 aluminium alloy components by a conventional powder metallurgical processing technique, involving the uniaxial cold pressing and sintering of composite powders. Three aluminium alloy powder

G. O'Donnell; L. Looney

2001-01-01

64

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

65

Aluminium Sheet Metal Forming at Low Temperatures  

NASA Astrophysics Data System (ADS)

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

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

2015-02-01

66

Aluminium, carbonyls and cytokines in human nipple aspirate fluids: Possible relationship between inflammation, oxidative stress and breast cancer microenvironment.  

PubMed

The human breast is likely exposed to Al (aluminium) from many sources including diet and personal care products. Underarm applications of aluminium salt-based antiperspirant provide a possible long-term source of exposure, especially after underarm applications to shaved and abraded skin. Al research in breast fluids likely reflects the intraductal microenvironment. We found increased levels of aluminium in noninvasively collected nipple aspirate fluids (NAF) from 19 breast cancer patients compared with 16 healthy control subjects (268 vs 131 ?g/l, respectively; p < 0.0001). In the same NAF samples we found significantly increased levels of protein oxidative carbonyls in cancer patients compared to healthy women (2.35 vs 0.41 nmol/mg prot, respectively; p < 0.0001). Aluminium content and carbonyl levels showed a significant positive linear correlation (r(2) 0.6628, p < 0.0001). In cancer NAF samples (containing higher amounts of aluminium salts) we also found a significantly increased levels of pro-inflammatory cytokines (IL-1?, IL-6, IL-12 p70, and TNF-?) and chemoattractant CC and CXC chemokines (IL-8, MIP-1? and MCP-1). In 12 invasive cancer NAF samples we found a significant positive linear correlation among aluminium, carbonyls and pro-inflammatory IL-6 cytokine (Y = 64.79x-39.63, r(2) 0.8192, p < 0.0005), as well as pro-inflammatory monocyte chemoattractant MCP-1 cytokine (Y = 2026x-866, r(2) 0.9495, p < 0.0001). In addition to emerging evidence, our results support the possible involvement of aluminium ions in oxidative and inflammatory status perturbations of breast cancer microenvironment, suggesting aluminium accumulation in breast microenvironment as a possible risk factor for oxidative/inflammatory phenotype of breast cells. PMID:23916117

Mannello, F; Ligi, D; Canale, M

2013-11-01

67

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

68

Electrogeneration of aluminium to remove silica in water.  

PubMed

This paper presents the results of a study on electrogeneration of aluminium, as a coagulant to remove silica in make-up water for cooling towers. Three electrochemical systems were tested, two with aluminium electrodes (one with polarity change and another without it), and a third one with aluminium anodes and cathodes of stainless steel. From the obtained results it was concluded that under the studied conditions, the most advantageous system to produce aluminium and remove silica is the one with both electrodes of aluminium working with direct current. Due to chemical production of aluminium at the cathode, the concentration of aluminium in the water at the outlet of the electrochemical reactor is much higher than the one calculated according to Faraday's law. Under the tested conditions it was possible to remove up to 66% of silica from water containing around 50 mg L(-1). PMID:22258672

Gelover-Santiago, S L; Pérez-Castrejón, S; Martín-Domínguez, A; Villegas-Mendoza, I E

2012-01-01

69

Tribological simulation of aluminium hot extrusion  

Microsoft Academic Search

Hot extrusion is a very cost efficient method of aluminium forming. One limitation for further improvement of cost reduction is wear of the bearing surface on the die which deteriorates the dimensional tolerance and surface quality of the profile. Nitrided hot work tool steels are commonly used as die material but new surface treatments are being introduced. This paper describes

Thomas Björk; Jens Bergström; Sture Hogmark

1999-01-01

70

Effect of aluminium chloride on human spermatozoa  

SciTech Connect

Aluminium (Al), which is the most prevalent metal in the earth's crust, has been implicated as an etiological factor in a variety of clinical disorders. Only recently Al has been discussed in the pathogenesis of the parenteral nutrition - associated liver disease. Included in this report are the preliminary findings on its effects on the reproductive functions of human beings.

Kaur, S.

1988-03-01

71

Ultraprecision diamond turning of aluminium single crystals  

Microsoft Academic Search

Ultraprecision diamond turning is an important technology to generate a high surface finish in precision components and optics. In this paper, the diamond turning of aluminium single crystal rods with crystallographic axes normal to , and is analysed. The effect of the crystallographic anisotropy on the machining of these single crystals is investigated in the light of the mechanics of

S. To; W. B. Lee; C. Y. Chan

1997-01-01

72

Friction stir welding of aluminium casting alloys  

Microsoft Academic Search

It has been presented the results of testing of friction stir welding quality in relation to EN AC-43200 (AK9) and EN AC-45000 (AK64) aluminium casting alloys. The test joints were made with the use of the welding machine constructed on the basis of numerically controlled milling machines. The assessment of the joints quality was made basing oneself on the visual

Damian Miara; Adam Pietras

2012-01-01

73

Adhesive bonding between aluminium and polytetrafluoroethylene  

Microsoft Academic Search

Requirements to join dissimilar materials are more and more frequent in new technologies. The paper deals with a study of a joint between aluminium pieces and polytetrafluoroethylene (PTFE) pieces. The way of their joining is described. The joint was performed through soldering with adhesive that covered on joining surfaces of the pieces, processed at a certain roughness, in a well-established

Elena David; A Lazar

2003-01-01

74

Visual detection and sequential injection determination of aluminium using a cinnamoyl derivative.  

PubMed

A cinnamoyl derivative, 3-[4-(dimethylamino)cinnamoyl]-4-hydroxy-6-methyl-3,4-2H-pyran-2-one, was used as a ligand for the determination of aluminium. Upon the addition of an acetonitrile solution of the ligand to an aqueous solution containing Al(III) and a buffer solution at pH 8, a marked change in colour from yellow to orange is observed. The colour intensity is proportional to the concentration of Al(III); thus, the 'naked-eye' detection of aluminium is possible. The reaction is also applied for sequential injection determination of aluminium. Beer?s law is obeyed in the range from 0.055 to 0.66 mg L(-1) of Al(III). The limit of detection, calculated as three times the standard deviation of the blank test (n=10), was found to be 4 ?g L(-1) for Al(III). The method was applied for the determination of aluminium in spiked water samples and pharmaceutical preparations. PMID:25435222

Ele?ková, Lenka; Alexovi?, Michal; Kuchár, Juraj; Balogh, Ioseph S; Andruch, Vasil

2015-02-01

75

Synthesis of Zeolite from Aluminium Etching By-Product: The Effect of Reaction Temperature on Crystallinity and Its CO2 Adsorption Property  

Microsoft Academic Search

The synthesis of zeolite from the by-product of aluminium etching process was investigated. The starting by-product reactant had high aluminium content, 92.17% wt. as Al2O3. Si and Na compositions were adjusted by the addition of sodium metasilicate, in the hydrogel process.The reaction time was fixed at 1 h., while the stirring speed was controlled at 200 rpm. and the temperature

Supaporn Douglas

2008-01-01

76

Friction and wear of ion implanted aluminium  

NASA Astrophysics Data System (ADS)

Pure commercial aluminium was implanted with boron, nitrogen oxygen and tin ions to doses of between 10 10 and 10 17 ions/cm 2 and at energies of 340 keV or 400 keV. Lubricated sliding-wear experiments using a pin-on-disc machine have shown a significant improvement in wear and friction. No direct correlations between friction and wear variations have been observed, indicating the complicated nature of both processes. The observed change in friction and wear is considered to be due to an alteration in the surface oxidation properties of aluminium brought about by the ion implantation, the interaction of implanted ions with dislocations, the precipitation of hard phase particles, and the overall effect of these processes on the initiation and propagation of wear cracks. The analytical techniques used included Rutherford backscattering, optical microscopy and topography.

Madakson, Peter B.; Smith, Anthony A.

1983-05-01

77

Mechanical Properties of Particulate Reinforced Aluminium Alloy Matrix Composite  

SciTech Connect

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

2011-01-17

78

Sustainability of the European Aluminium Industry 2010  

NSDL National Science Digital Library

This report by the European Aluminium Association (EAA) was created to analyze and document the efforts of Europe’s aluminum industry to remain competitive, grow, and become more environmentally friendly. Recommendations and reviews are formed based on 34 “Sustainable Development Indicators.” New in the 2010 report is the use sustainability indicators to address the use of aluminum in key applications. Highlighted improvements for 2010 are emissions, natural resource use, worker safety, training, and recycling.

2013-07-29

79

Aluminium phosphide poisoning: a case report.  

PubMed

This paper reports the case of a family in which three children were presented at Emergency Room (ER) with poisoning after the use of a pesticide at home. Initially, the cases were managed as routine cases of organophosphorus poisoning; however, the death of two children made the health team members realise that the poison's effects were delayed and devastating. Later, the compound was identified as Aluminium Phosphide (ALP), and the life of the last surviving child in the family was saved. PMID:22455303

Hirani, Shela Akbar Ali; Rahman, Arshalooz

2010-01-01

80

An ultrafast rechargeable aluminium-ion battery.  

PubMed

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

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

2015-04-16

81

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

82

Improving the Crashworthiness of Aluminium Rail Vehicles  

NASA Astrophysics Data System (ADS)

An experimental and modelling programme of work have been undertaken to predict the performance of aluminium welds in rail vehicles under highly dynamic loading conditions and provide design guidelines to reduce the likelihood of the occurrence of weld unzipping. Modelling of weld unzipping in large rail structures is a challenging task since it requires to deal with material instability, to take into account the uncertainties in material parameters and to address the problem of mesh resolution which together pose severe challenges to computability. The proposed methodology to the prediction of weld failure is based on the validation of the numerical models through correlation with laboratory scale tearing tests. The tearing tests were conducted on samples taken from real rail extrusions with the purpose of obtaining the failure parameters under dynamic loading and understanding the effect of weld material composition on joint behaviour. The validated material models were used to construct a FEA simulation of the collision of an aluminium rail car and investigate the effect of both joint geometry and welding techniques on the failure mechanism. Comparisons of the model with the failures observed in an aluminium rail vehicle that was involved in a high speed collision, have shown that it is possible to model the phenomenon of weld unzipping with good accuracy. The numerical models have also been used as a tool for the optimisation of joint design to improve crashworthiness.

Zangani, Donato; Robinson, Mark; Kotsikos, George

83

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

84

Short report: plasma aluminium concentration and 24-hour urinary aluminium excretion before, during and after treatment with sucralfate.  

PubMed

Ten dyspeptic patients were treated with 1 g sucralfate q.d.s. for six weeks. The plasma aluminium concentration and 24-h urinary aluminium excretion were measured at 3-weekly intervals before, during and after treatment with sucralfate. Compared with before treatment, there were significant rises in the median plasma aluminium concentration at 3 and 6 weeks during treatment with sucralfate (6 micrograms/L to 13 and 12 micrograms/L). The median 24-h urinary aluminium excretion rose significantly from a pretreatment level of 20 micrograms to 71 and 78 micrograms after 3 and 6 weeks of treatment; the significant increase of urinary aluminium excretion persisted for three weeks after cessation of treatment (52 micrograms/24 hours), but thereafter urinary excretion was not significantly different from pretreatment. The results are consistent with significant absorption and tissue accumulation of aluminium during standard treatment with sucralfate in individuals with normal renal function. PMID:1793786

Mistry, P; Varghese, Z; Pounder, R E

1991-10-01

85

Spectrophotometric determination of aluminium with bromopyrogallol red and a quaternary ammonium salt: Determination of aluminium in river water  

Microsoft Academic Search

Summary In the presence ofn-tetradecyltrimethylammonium bromide aluminium reacts with Bromopyrogallol Red (BPR) to form a ternary complex, in which the molar ratio of aluminium ot BPR is 1:2. The method is suitable for the determination of traces of aluminium in natural waters. The ternary complex has an absorbance maximum at 623 mm with molar absorptivity 5.05×104 l · mole-1 ·

Czes?aw Wyganowski; Shoji Motomizu; Kyoji Tôei

1983-01-01

86

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. PMID:20610489

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

2010-01-01

87

Addition Fun!  

NSDL National Science Digital Library

Students will have the opportunity to practice their additions skills through a variety of addition games. To practice addition, click Memory Addition! Race the clock while learning your addition facts. Click on Flashcard Races. For this last game, come and get me so I can watch and check you addition skills! Click Last Game! ...

Mrs. Bingham

2007-11-27

88

Speciation analysis of aluminium and aluminium fluoride complexes by HPIC-UVVIS.  

PubMed

The study presents a new analytical method for speciation analysis in fractionation of aluminium fluoride complexes and free Al(3+) in soil samples. Aluminium speciation was studied in model solutions and soil extract samples by means of high performance ion chromatography (HPIC) with UV-VIS detection using post-column reaction with tiron for the separation and detection of aluminium fluoride complex and Al(3+) forms during one analysis. The paper presents particular stages of the chromatographic process optimization involving selecting the appropriate eluent strength, type of elution or concentration and quantity of derivatization reagent. HPIC was performed on a bifunctional analytical column Dionex IonPac CS5A. The use of gradient elution and the eluents A: 1M NH(4)Cl and B: water acidified to pH of eluent phase, enabled full separation of fluoride aluminium forms as AlF(2)(+), AlF(3)(0), AlF(4)(-) (first signal), AlF(2+) (second signal) and form Al(3+) in a single analytical procedure. The proposed new method HPIC-UVVIS was applied successfully in the quantitative and qualitative analysis of soil samples. PMID:20875574

Frankowski, Marcin; Zio?a-Frankowska, Anetta

2010-10-15

89

Addition Facts  

NSDL National Science Digital Library

Play these addition games to review your addition facts. 1. First, to review of your addition facts you will practice them by using these flashcards. Flashcards After you review your addition facts by using the flashcards, you get to play some addition games! Try your hardest and have fun! 2. Play this addition fishing game Addition Fishing Game 3. Next you get to practice your ...

Ms. Felsted

2010-04-12

90

Diffusion Bonding Aluminium Alloys and Composites: New Approaches and Modelling  

E-print Network

is entirely my own and includes nothing which is the outcome of work done in collaboration, except where. This work was financially supported by the Ministry of Higher Education of Iran, the Committee of Vice of the research, two new methods for TLP diffusion bonding of aluminium-based composites (aluminium alloys

Cambridge, University of

91

Aluminium–related osteomalacia: response to reverse osmosis water treatment  

Microsoft Academic Search

Aluminium–related osteomalacia: response to reverse osmosis water treatment. It is generally accepted that aluminium induces osteomalacia in chronic hemodialysis patients by binding to the calcification front, thereby inhibiting mineralization of osteoid. Because this form of osteomalacia is vitamin D resistant, the condition has often been assumed to be irreversible, although promising results have been achieved recently by using a chelating

George D Smith; Robin J Winney; Alexander McLean; James S Robson

1987-01-01

92

Developments in finite element simulations of aluminium extrusion  

Microsoft Academic Search

Aluminium extrusion is a forming process used to produce profiles. A large variety of profiles can be made by pressing a billet of hot aluminium through a hole that closely resembles the required cross-section of the profie. At the present time, design of extrusion dies and operation in extrusion companies is primarily based on trial and error. The experience of

Joeri Lof

2000-01-01

93

FEM analysis of aluminium extrusion through square and round dies  

Microsoft Academic Search

Understanding the state of stress, strain and the temperature of an aluminium alloy going through a die during extrusion is of great importance for running the aluminium extrusion process, because they are closely related to the surface quality of the extruded products, throughput and scrap rate. It has been made clear that surface tearing is mainly caused by excessive local

T. Chanda; J. Zhou; J. Duszczyk

2000-01-01

94

Electron microscopy and diffraction of aluminium oxide whiskers  

Microsoft Academic Search

Whiskers of ?-Al2O3 have been grown by the condensation and oxidation of aluminium on an alumina substrate, and examined by transmission electron microscopy and diffraction. Unbroken whiskers invariably terminate in a small globule of aluminium and have a ‘drumstick’ form. The most perfect whiskers are ribbons with their principal surfaces parallel to the (0001) planes; the majority of these have

D. J. Barber

1964-01-01

95

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

96

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

97

Galvanised steel to aluminium joining by laser and GTAW processes  

SciTech Connect

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. The interfaces generated during the interaction were mainly composed of a 2-40 {mu}m thick intermetallic reaction layers. The linear strength of the assemblies can be as high as 250 N/mm and 190 N/mm for the assemblies produced respectively by laser and GTAW processes. The corresponding failures were located in the fusion zone of aluminium (laser assemblies), or in the reaction layer (GTAW assemblies)

Sierra, G. [CEA/DRT/DTEN/LITEN/UTIAC, Groupement d'Etudes et de Recherche pour l'Application Industrielle des Lasers de Puissance (GERAILP), Arcueil, 94114 (France); Universite Montpellier 2, Laboratoire de Mecanique et Genie Civil, UMR 5508 CNRS, Montpellier, 34095 (France); Peyre, P. [GIP-GERAILP, Laboratoire pour l'Application des Lasers de Puissance, UPR 1578 CNRS, Arcueil, 94114 (France); Deschaux Beaume, F. [Universite Montpellier 2, Laboratoire de Mecanique et Genie Civil, UMR 5508 CNRS, Montpellier, 34095 (France)], E-mail: deschaux@iut-nimes.fr; Stuart, D. [GIP-GERAILP, Laboratoire pour l'Application des Lasers de Puissance, UPR 1578 CNRS, Arcueil, 94114 (France); Fras, G. [Universite Montpellier 2, Laboratoire de Mecanique et Genie Civil, UMR 5508 CNRS, Montpellier, 34095 (France)

2008-12-15

98

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

99

Volatilisation and oxidation of aluminium scraps fed into incineration furnaces  

SciTech Connect

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

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

2012-12-15

100

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 ...

Ms. Staggs

2008-04-01

101

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 ...

Ms. Bolton

2009-04-22

102

Urinary excretion of aluminium after ingestion of sucralfate and an aluminium-containing antacid in man.  

PubMed

Eleven subjects with normal renal function were given, on 2 separate days, at least 1 week apart, four tablets of sucralfate or an aluminium (Al)-containing antacid. The total Al load was approximately 976 mg with the antacid and approximately 828 mg with sucralfate. The daily urinary excretion of Al was measured the day before and during 3 days after drug administration. Al excretion increased significantly after both drugs. There was no significant difference between the two products. The median absorption calculated as percentage of Al dose was 0.005% (range, 0.001-0.017%) for sucralfate and 0.006% (range, 0.002-0.060%) for the antacid. Thus, measurable quantities of aluminium is absorbed after administration of sucralfate, and the drug should, like Al-containing antacids, be given with caution to patients with renal failure. PMID:3629187

Haram, E M; Weberg, R; Berstad, A

1987-06-01

103

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

Microsoft Academic Search

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

Moshe Ish-Shalom; Wright-Patterson AFB

1982-01-01

104

Aluminium and iron air pollution near an iron casting and aluminium foundry in Turin district (Italy).  

PubMed

This work reports the results of an environmental survey carried out in an industrial area in the Province of Turin: its main aim is to assess the levels of iron and aluminium in the outside air during the period from July to September to assess the influence of industrial activity (a cast-iron and aluminium foundry) which is interrupted during the month of August, on the level of metals present in the air. Conducting the analysis during this period of time made it possible to avoid the confounding effect of pollution due to domestic central heating. The measurements were taken from nine areas at different distances from the foundry in the area and according to the direction of the prevailing winds, as deduced from the historical data. The results of this survey show a statistically significant difference in iron and aluminium levels in the outside air in the geographic areas between the two main periods examined: during August (no foundry activity) v/s July-September (foundry activity). The values recorded are: Aluminium 0.4+/-0.45 microg/m(3) v/s 1.12+/-1.29 microg/m(3) (p<0.0001); Iron 0.95+/-0.56 microg/m(3) v/s 1.6+/-1.0 microg/m(3) (p<0.0001). There were no statistically significant differences between the nine sampling points from the point of view of the sampling sites, climate conditions and wind directions. We found no correlation with car traffic, in terms of the number of vehicles, and metals. The values of iron tended to be higher in the areas farther away from the foundry site in the areas located along the path of the prevailing winds. PMID:17637476

Polizzi, Salvatore; Ferrara, Mauro; Bugiani, Massimiliano; Barbero, Domenico; Baccolo, Tiziana

2007-09-01

105

A micro heat exchanger microfabricated from bulk aluminium  

NASA Astrophysics Data System (ADS)

We report a micro heat exchanger microfabricated from a bulk aluminium alloy substrate. The device is comprised of two 18 cm long microchannels, one on each side of an aluminium chip, capped on both sides with a thin self-adhesive polymer film. In spite of a cheap and facile fabrication method, initial experiments with the device show promising results. Area densities from 25000 m?1 to 45000 m?1 have been achieved. Compared to our previous work on aluminium microfluidic devices produced with a similar technology but from a different, less pure alloy, in this study the etched surfaces are significantly smoother, and present less photoresist delamination.

Scotti, G.; Franssila, S.

2014-11-01

106

A quest for super dense aluminium  

NASA Astrophysics Data System (ADS)

The extreme pressure phase diagram of materials is important not only for understanding the interiors of planets or stars, but also for the fundamental understanding of the relation between crystal structure and electronic structure. Structural transitions induced by extreme pressure are governed by the deformation of valence electron charge density which bears the brunt of increasing compression while the relative volume occupied by the nearly incompressible ionic core electrons increases. At extreme pressures common materials are expected to transform into new dense phases with extremely compact atomic arrangements that may also have unusual physical properties. In this report, we present new experiments carried out on aluminium. A simple system like Al is not only important as a benchmark for theory, but can also be used as a standard for pressures in the TPa range and beyond which are targeted at new dynamic compression facilities such as the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory in the US or Laser Mégajoule (LMJ) in Bordeaux in France. For aluminium, first principle calculations have consistently predicted a phase transition sequence from fcc to hcp and hcp to bcc in a pressure range below 0.5 TPa [Tambe et al., Phys. Rev. B 77, 172102, 2008]. The hcp phase was identified at 217 GPa in a recent experiment [Akahama et al., Phys. Rev. Lett. 96, 45505, 2006] but the detection of the predicted bcc phase has been hampered by the difficulty of routine static high pressure experiments beyond 350 GPa. Here, we report on the overcoming of this obstacle and the detection of all the structural phase transitions predicted in Al by achieving a pressure in excess of 500 GPa in the static regime in a diamond-anvil cell. In particular, using X-ray diffraction at the high-pressure beamline ID27 at the European Synchrotron Radiation Facility (ESRF), we find a bcc super-dense phase of aluminium at a pressure of 380 GPa. In this report, we provide detailed information on this phase transition as well as details on how to achieve controlled static experiments in the range 3 to 5 Mbar.

Fiquet, G.; Narayana, C.; Bellin, C.; Shukla, A.; Esteve, I.; Mezouar, N.

2013-12-01

107

Food additives  

MedlinePLUS

Food additives are substances that become part of a food product when they are added during the processing or making of that food. "Direct" food additives are often added during processing to: Add nutrients ...

108

[Determination of beryllium in atmospheric particulate by graphite furnace atomic absorption spectrophotometer using aluminium as a matrix modifier agent sampling with micropore filter membrane].  

PubMed

Beryllium in the atmospheric particulates is collected with 0.22 micron pore diameter micropore filter membrane, which is determined by graphite furnace atomic absorption spectrophotometer using aluminium as a matrix modifier agent. This sampling method shown several advantages: easy, complete and fast digestion; low membrane blank; high elution recovery, standard addition recovery, precision and accuracy. The addition of 800 mg.L-1 aluminium to beryllium solution allows ashing temperature of 2,000 degrees C. The detection limit of 13.5 ng was obtained. PMID:12945289

Wang, Z; Zhu, W; Lu, Y

2001-08-01

109

Food additives  

PubMed Central

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

Spencer, Michael

1974-01-01

110

Crystalline silicon core fibres from aluminium core preforms.  

PubMed

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

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

2015-01-01

111

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.

2013-07-17

112

Sulfone-based electrolytes for aluminium rechargeable batteries.  

PubMed

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

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

2015-02-10

113

Crystalline silicon core fibres from aluminium core preforms  

NASA Astrophysics Data System (ADS)

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

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

2015-02-01

114

Aluminium alloys in municipal solid waste incineration bottom ash.  

PubMed

With the increasing growth of incineration of household waste, more and more aluminium is retained in municipal solid waste incinerator bottom ash. Therefore recycling of aluminium from bottom ash becomes increasingly important. Previous research suggests that aluminium from different sources is found in different size fractions resulting in different recycling rates. The purpose of this study was to develop analytical and sampling techniques to measure the particle size distribution of individual alloys in bottom ash. In particular, cast aluminium alloys were investigated. Based on the particle size distribution it was computed how well these alloys were recovered in a typical state-of-the-art treatment plant. Assessment of the cast alloy distribution was carried out by wet physical separation processes, as well as chemical methods, X-ray fluorescence analysis and electron microprobe analysis. The results from laboratory analyses showed that cast alloys tend to concentrate in the coarser fractions and therefore are better recovered in bottom ash treatment plants. PMID:19423581

Hu, Yanjun; Rem, Peter

2009-05-01

115

Raman spectroscopy of aromatic acids adsorbed on oxidised aluminium foil  

Microsoft Academic Search

Adsorption of ortho- and para-phthalic acids on oxidised aluminium foil was investigated by Raman and surface-enhanced Raman spectroscopy (SERS). Without any treatment of the foil only a modified method of SERS provided spectroscopic evidence of the adsorption. However, by dissolving the metal aluminium from the Al2O3?Al?Al2O3 structure of the foil, the adsorption could be investigated by Raman spectroscopy without surface-enhanced

O. Klug; Gy. Parlagh; W. Forsling

1997-01-01

116

Reduction of turbidity by a coal-aluminium filter  

SciTech Connect

Coal-aluminium granular filters successfully reduce turbidity in low-alkalinity raw waters to less than 1.0 ntu, without a coagulation step or external coagulant aids. Data from experiments conducted with control and pilot-plant filters show the viability of the process and indicate the turbidity and retention mechanisms. Operational characteristics of the process are similar to those of a conventional filter. The costs of the coal-aluminium process compare favourably with those of traditional treatment.

Collins, A.G.; Johnson, R.L.

1985-06-01

117

Reactively sputtered aluminium nitride films for spectral emission control  

Microsoft Academic Search

Aluminium nitride films, 0.8-1.8 mum thick, have been deposited by reactive, magnetron sputtring of aluminium in an argon-nitrogen atmosphere. The sputtered films exhibit a Reststrahlen band in the wavelength range 11-16 mum. We have investigated the possibilities to use different substrate materials and dielectric coatings to extend this interval to the entire upper thermal window 8-13 mum and a secondary

S. Zhao; C.-G. Ribbing

2008-01-01

118

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

119

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

120

Modelling of Local Necking and Fracture in Aluminium Alloys  

SciTech Connect

Non-linear Finite Element simulations are extensively used in forming and crashworthiness studies of automotive components and structures in which fracture need to be controlled. For thin-walled ductile materials, the fracture-related phenomena that must be properly represented are thinning instability, ductile fracture and through-thickness shear instability. Proper representation of the fracture process relies on the accuracy of constitutive and fracture models and their parameters that need to be calibrated through well defined experiments. The present study focuses on local necking and fracture which is of high industrial importance, and uses a phenomenological criterion for modelling fracture in aluminium alloys. As an accurate description of plastic anisotropy is important, advanced phenomenological constitutive equations based on the yield criterion YLD2000/YLD2003 are used. Uniaxial tensile tests and disc compression tests are performed for identification of the constitutive model parameters. Ductile fracture is described by the Cockcroft-Latham fracture criterion and an in-plane shear tests is performed to identify the fracture parameter. The reason is that in a well designed in-plane shear test no thinning instability should occur and it thus gives more direct information about the phenomenon of ductile fracture. Numerical simulations have been performed using a user-defined material model implemented in the general-purpose non-linear FE code LS-DYNA. The applicability of the model is demonstrated by correlating the predicted and experimental response in the in-plane shear tests and additional plane strain tension tests.

Achani, D. [Structural Design, Offshore Construction Engineering, SUBSEA7, NO-4056 Tananger (Norway); Eriksson, M. [SINTEF Materials and chemistry, Applied mechanics and corrosion, NO-7465 Trondheim (Norway); Hopperstad, O. S. [SIMLab, Department of Structural Engineering, Norwegian University of Science and Technology, NO-7491 Trondheim (Norway); Lademo, O.-G. [SINTEF Materials and chemistry, Applied mechanics and corrosion, NO-7465 Trondheim (Norway); SIMLab, Department of Structural Engineering, Norwegian University of Science and Technology, NO-7491 Trondheim (Norway)

2007-05-17

121

Modelling of Local Necking and Fracture in Aluminium Alloys  

NASA Astrophysics Data System (ADS)

Non-linear Finite Element simulations are extensively used in forming and crashworthiness studies of automotive components and structures in which fracture need to be controlled. For thin-walled ductile materials, the fracture-related phenomena that must be properly represented are thinning instability, ductile fracture and through-thickness shear instability. Proper representation of the fracture process relies on the accuracy of constitutive and fracture models and their parameters that need to be calibrated through well defined experiments. The present study focuses on local necking and fracture which is of high industrial importance, and uses a phenomenological criterion for modelling fracture in aluminium alloys. As an accurate description of plastic anisotropy is important, advanced phenomenological constitutive equations based on the yield criterion YLD2000/YLD2003 are used. Uniaxial tensile tests and disc compression tests are performed for identification of the constitutive model parameters. Ductile fracture is described by the Cockcroft-Latham fracture criterion and an in-plane shear tests is performed to identify the fracture parameter. The reason is that in a well designed in-plane shear test no thinning instability should occur and it thus gives more direct information about the phenomenon of ductile fracture. Numerical simulations have been performed using a user-defined material model implemented in the general-purpose non-linear FE code LS-DYNA. The applicability of the model is demonstrated by correlating the predicted and experimental response in the in-plane shear tests and additional plane strain tension tests.

Achani, D.; Eriksson, M.; Hopperstad, O. S.; Lademo, O.-G.

2007-05-01

122

New aluminium-rich alkali slag matrix with clay minerals for immobilizing simulated radioactive Sr and Cs waste  

Microsoft Academic Search

A new aluminium-rich alkali-activated slag matrix (M-AAS) with clay absorbents has been developed for immobilization of simulated radioactive Sr or Cs waste by introducing metakaolin, natural zeolite and NaOH-treated attapulgite clay minerals into alkali-activated slag matrix (AAS). The results revealed that the additions of metakaolin and clay absorbents into the cementitious matrixes would greatly enhance the distribution ratio, Rd, of

Guangren Qian; Darren Delai Sun; Joo Hwa Tay

2001-01-01

123

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

PubMed

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

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

2011-10-01

124

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

125

A systematic review of aluminium phosphide poisoning.  

PubMed

Every year, about 300,000 people die because of pesticide poisoning worldwide. The most common pesticide agents are organophosphates and phosphides, aluminium phosphide (AlP) in particular. AlP is known as a suicide poison that can easily be bought and has no effective antidote. Its toxicity results from the release of phosphine gas as the tablet gets into contact with moisture. Phosphine gas primarily affects the heart, lungs, gastrointestinal tract, and kidneys. Poisoning signs and symptoms include nausea, vomiting, restlessness, abdominal pain, palpitation, refractory shock, cardiac arrhythmias, pulmonary oedema, dyspnoea, cyanosis, and sensory alterations. Diagnosis is based on clinical suspicion, positive silver nitrate paper test to phosphine, and gastric aspirate and viscera biochemistry. Treatment includes early gastric lavage with potassium permanganate or a combination with coconut oil and sodium bicarbonate, administration of charcoal, and palliative care. Specific therapy includes intravenous magnesium sulphate and oral coconut oil. Moreover, acidosis can be treated with early intravenous administration of sodium bicarbonate, cardiogenic shock with fluid, vasopresor, and refractory cardiogenic shock with intra-aortic baloon pump or digoxin. Trimetazidine may also have a useful role in the treatment, because it can stop ventricular ectopic beats and bigeminy and preserve oxidative metabolism. This article reviews the epidemiological, toxicological, and clinical/pathological aspects of AlP poisoning and its management. PMID:22450207

Mehrpour, Omid; Jafarzadeh, Mostafa; Abdollahi, Mohammad

2012-03-01

126

Macronutrients, aluminium from drinking water and foods, and other metals in cognitive decline and dementia.  

PubMed

A possible role of the macronutrients and the basic elements of carbohydrates (glucose administration or depletion), proteins (amino acids such as tryptophan and tyrosine), and fat (unsaturated fatty acids) was recently proposed for age-related changes of cognitive function, and the cognitive decline of degenerative (AD) or vascular origin. The availability and utilization of glucose has been implicated in cognitive function not only as a result of nutritional and systemic metabolic conditions, but also, although speculatively, as a crucial phase of the mechanism of action of molecules used as cognitive-enhancers. Furthermore, many lines of evidence have focused on the importance of oxidative stress mechanisms and free radical damage in AD pathogenesis. In addition, epidemiological studies have recently reported an association between alcohol and the incidence of AD and predementia syndromes. Foods with large amounts of aluminium-containing additives or aluminium from drinking water may affect the risk of developing AD, aluminium more likely acting as a cofactor somewhere in the cascade of events leading to the demented brain. A role for other metals in dementia have been speculated, given the encouraging results reported from studies on peripheral zinc concentrations, zinc supplementation, serum copper, either bound with ceruloplasmin or not, and iron metabolism in AD. Nonetheless, more data are needed to support a possible role of these metals in dementing diseases. Healthy diets, antioxidant supplements, and the prevention of nutritional deficiencies or exposure to foods and water with high content of metals could be considered the first line of defence against the development and progression of cognitive decline. PMID:17119295

Solfrizzi, Vincenzo; Colacicco, Anna Maria; D'Introno, Alessia; Capurso, Cristiano; Parigi, Angelo Del; Capurso, Sabrina A; Torres, Francesco; Capurso, Antonio; Panza, Francesco

2006-11-01

127

Color Addition  

NSDL National Science Digital Library

This activity is inquiry in that students do not know how colors are combined. They likely think that the primary colors are red, yellow, and blue. In fact, there are two sets of primary colors: red, green, and blue for additive colors of light, and cyan,

Michael Horton

2009-05-30

128

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

129

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

130

Acute epidemic aluminium osteomalacia secondary to water supply contamination.  

PubMed

When the aluminium content of the water supply to our Haemodialysis Unit rose from less than 0.5 mumol/l to 6 mumol/l over a two month period, we carried out bone biopsies and desferrioxamine infusion tests on twelve (12) patients who had been on haemodialysis for less than one year (mean 8 months) and had normal serum aluminium levels. The patients had no bone symptoms. Eight patients had positive aluminium bone stains. The aluminium osteomalacia group (n = 8) had a mean PTH of 1.4 ng/ml s.e. 0.3 whereas the non-ALO group had a mean PTH of 2.9 ng/ml s.e. 0.7. The difference in mean PTH is significant (p less than 0.05). There was no evidence of encephalopathy, fractures or microcytic anaemia in the ALO positive group. The aluminium contamination of the water supply occurred because of a change in the reservoir purification system from sand-filtration to alum. PMID:2361822

O'Brien, A A; Moore, D P; Keogh, J A

1990-03-01

131

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

132

Phosphazene additives  

DOEpatents

An additive comprising a phosphazene compound that has at least two reactive functional groups and at least one capping functional group bonded to phosphorus atoms of the phosphazene compound. One of the at least two reactive functional groups is configured to react with cellulose and the other of the at least two reactive functional groups is configured to react with a resin, such as an amine resin of a polycarboxylic acid resin. The at least one capping functional group is selected from the group consisting of a short chain ether group, an alkoxy group, or an aryloxy group. Also disclosed are an additive-resin admixture, a method of treating a wood product, and a wood product.

Harrup, Mason K; Rollins, Harry W

2013-11-26

133

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

PubMed Central

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

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

2001-01-01

134

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

Microsoft Academic Search

In mice the oral LD50 values of aluminium chloride and aluminium sulphate were 0·77 ± 0·12 and 0·98 ± 0·09 g. Al\\/kg. (± S.E.) respectively.Mice and rats were fed on a normal diet containing about 170 p.p.m. of aluminium. Doubling this concentration caused a decrease in growth in the second and third generations of mice. A high intake of aluminium

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

1966-01-01

135

Absolutely Addition  

NSDL National Science Digital Library

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

Mrs. Korth

2005-03-23

136

Determination of aluminium in groundwater samples by GF-AAS, ICP-AES, ICP-MS and modelling of inorganic aluminium complexes.  

PubMed

The paper presents the results of aluminium determinations in ground water samples of the Miocene aquifer from the area of the city of Pozna? (Poland). The determined aluminium content amounted from <0.0001 to 752.7 ?g L(-1). The aluminium determinations were performed using three analytical techniques: graphite furnace atomic absorption spectrometry (GF-AAS), inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS). The results of aluminium determinations in groundwater samples for particular analytical techniques were compared. The results were used to identify the ascent of ground water from the Mesozoic aquifer to the Miocene aquifer in the area of the fault graben. Using the Mineql+ program, the modelling of the occurrence of aluminium and the following aluminium complexes: hydroxy, with fluorides and sulphates was performed. The paper presents the results of aluminium determinations in ground water using different analytical techniques as well as the chemical modelling in the Mineql+ program, which was performed for the first time and which enabled the identification of aluminium complexes in the investigated samples. The study confirms the occurrence of aluminium hydroxy complexes and aluminium fluoride complexes in the analysed groundwater samples. Despite the dominance of sulphates and organic matter in the sample, major participation of the complexes with these ligands was not stated based on the modelling. PMID:21274747

Frankowski, Marcin; Zio?a-Frankowska, Anetta; Kurzyca, Iwona; Novotný, Karel; Vaculovi?, Tomas; Kanický, Viktor; Siepak, Marcin; Siepak, Jerzy

2011-11-01

137

Stability constants of aluminium fluoride complexes.  

PubMed

Pointwise titrations of aluminium nitrate solutions with sodium fluoride were made at ionic strengths of 0.5, 0.2, 0.1 and 0.05M and at temperatures of 25 degrees and 37 degrees . The total Al(3+) concentration was kept constant at 5 x 10(-4)M and the total F(-) concentration covered the range 5-20 x 10(-4)M with a minimum of 20 points per titration. It is shown that only mononuclear complexes were present with these solution compositions. Determinations of H(+) and F(-) in solution were made by the use of quinhydrone and lanthanum fluoride electrodes, respectively. Formation constants were calculated by three different procedures. Best results were obtained by a non-linear generalized least-squares method that (a) permits calculation of the formation constants with the simultaneous presence of all the complexes being taken into account, (b) does not require segregation of data according to the values of the formation function (n), and (c) yields standard errors that reflect the errors in all the experimental measurements. Values for the formation constants at infinite dilution were obtained by a linear least-squares adjustment of the values obtained for the four finite ionic strengths. The formation constants thus obtained for the reaction AlF(n-1) + F <==> AlF(n) (charges omitted) at 25 degrees have logarithmic values of 6.69 +/- 0.02, 5.35 +/- 0.03, 3.68 +/- 0.01 and 2.75 +/- 0.04 for n = 1, 2, 3 and 4, respectively. The corresponding values at 37 degrees are 6.68 +/- 0.10,5.34 +/- 0.02,3.94 +/- 0.04, and 3.29 +/- 0.05. PMID:18960958

Agarwal, R P; Moreno, E C

1971-09-01

138

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

139

Aluminium in drinking water and cognitive decline in elderly subjects: the Paquid  

E-print Network

1 Aluminium in drinking water and cognitive decline in elderly subjects: the Paquid cohort.Rondeau@isped.u-bordeaux2.fr Key words: Cognitive decline, aluminium, silica, drinking water Word count : 954 inserm recently reported a significant association between the concentration of aluminium in drinking water

Paris-Sud XI, Université de

140

Different Approach to the Aluminium Oxide Topography Characterisation  

SciTech Connect

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

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

2007-04-07

141

Characterisation of Ga-coated and Ga-brazed aluminium  

SciTech Connect

This work is devoted to the brazing of aluminium using liquid gallium. Gallium was deposited on aluminium samples at {approx} 50 Degree-Sign C using a liquid gallium 'polishing' technique. Brazing was undertaken for 30 min at 500 Degree-Sign C in air. EDS (Energy Dispersive X-ray Spectroscopy) and AES (Auger Electron Spectroscopy) characterisation of Ga-coated samples has shown that the Ga surface layer thickness is of ten (or a few tens of) nanometres. Furthermore, aluminium oxide layer (Al{sub 2}O{sub 3}) was shown to be 'descaled' during Ga deposition, which ensures good conditions for further brazing. Cross-section examination of Ga-coated samples shows that liquid gallium penetrates into the aluminium grain boundaries during deposition. The thickness of the grain boundary gallium film was measured using an original EDS technique and is found to be of a few tens of nanometres. The depth of gallium grain boundary penetration is about 300 {mu}m at the deposition temperature. The fracture stress of the brazed joints was measured from tensile tests and was determined to be 33 MPa. Cross-section examination of brazed joints shows that gallium has fully dissolved into the bulk and that the joint is really autogenous. - Highlights: Black-Right-Pointing-Pointer Aluminium can be brazed using liquid gallium deposited by a 'polishing' technique. Black-Right-Pointing-Pointer The aluminium oxide layer is 'descaled' during liquid Ga 'polishing' deposition. Black-Right-Pointing-Pointer EDS can be used for determination of surface and grain boundary Ga film thickness. Black-Right-Pointing-Pointer The surface and grain boundary Ga film thickness is of a few tens of nm. Black-Right-Pointing-Pointer Surface and grain boundary gallium dissolves in the bulk during brazing.

Ferchaud, E. [Universite de Nantes, Polytech'Nantes, Laboratoire Genie des Materiaux et Procedes Associes, Rue Christian Pauc, 44306 Nantes Cedex 3 (France); Christien, F., E-mail: frederic.christien@univ-nantes.fr [Universite de Nantes, Polytech'Nantes, Laboratoire Genie des Materiaux et Procedes Associes, Rue Christian Pauc, 44306 Nantes Cedex 3 (France); Barnier, V. [Ecole Nationale Superieure des Mines, MPI, CNRS UMR5146, Centre SMS, 158 Cours Fauriel, 42023 Saint Etienne (France); Paillard, P. [Universite de Nantes, Polytech'Nantes, Laboratoire Genie des Materiaux et Procedes Associes, Rue Christian Pauc, 44306 Nantes Cedex 3 (France)

2012-05-15

142

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

143

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

144

A Numerical Analysis of the Resistance and Stiffness of the Aluminium and Concrete Composite Beam  

NASA Astrophysics Data System (ADS)

In this paper a numerical analysis of the resistance and stiffness of the aluminium and concrete composite beam is presented. Composite aluminium and concrete structures are quite new and they have not been thoroughly tested. Composite structures have a lot of advantages. The composite aluminium and concrete beam is more corrosion-resistant, fire-resistant and stiff than the aluminium beam. The contemporary idea of sustainable buildings relies on new solutions which are more environmentally friendly. Aluminium is lighter and more resistant to corrosion than steel, which is often used in composite structures.

Polus, ?ukasz; Szumiga?a, Maciej

2015-03-01

145

Titrimetric determination of aluminium in zinc-aluminium alloys, with edta and a cu(II)-selective electrode.  

PubMed

The end-point for the titration of EDTA with Cu(II), as measured by a Cu(II)-selective electrode, varies with pH and temperature. Moreover, the effect of pH and temperature on the behaviour of this electrode differs according to whether fluoride is present. As a consequence, the determination of aluminium in zinc-aluminium alloys by the Freegarde and Allen method with use of a Cu(II)-selective electrode must be performed with close control of pH and temperature to maximize accuracy and repeatability. PMID:18963452

Steger, H F

1983-09-01

146

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

147

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

PubMed

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

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

1990-04-01

148

The formation of precipitate phases in aluminium by ion implantation  

Microsoft Academic Search

The formation of precipitates of second phases during the ion implantation of thin metallic films is discussed in general terms. Observations from an electron microscope investigation of precipitation behaviour during the implantation of aluminium specimens with 70-80 kev Cu, Sb and Pb ions are described in detail. Special reference is made to the effects of radiation-enhanced diffusion and surface sputtering

P. A. Thackery; R. S. Nelson

1969-01-01

149

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

150

Development of an aluminium stabilized reinforced superconducting conductor  

SciTech Connect

For high performance superconducting magnets as used in large detectors for the High Energy Physics or for magnets of magnetic storage devices (SMES) the mechanical stresses on the conductor go beyond the yield stress level of the high purity matrix stabilizer, specially if aluminium is used. Therefore, a novel method is proposed to join high strength aluminium strips to high purity aluminium stabilizer by using the electron beam (EB) welding. The proposed EB-welding, combined with roll-pressing under vacuum, provides the minimum heat input on the conductor in comparison with other welding techniques. This method provides the advantage to allow the production of very long conductor lengths and includes the potentiality of repairing without losing expensive material. As this process has to be adapted to the high purity aluminium on the one side and to the high strength material on the other, the authors started in a first step with investigation and development of the process, using standard laboratory machines together with laboratory-size tooling. In this report the development program is described and first results of the quality control measurements are presented.

Fritz, D. [PTR Praezisionstechnik GmbH Maintal (Germany)] [PTR Praezisionstechnik GmbH Maintal (Germany); Horvath, I.L. [Swiss Federal Inst. of Tech., Zuerich (Switzerland)] [Swiss Federal Inst. of Tech., Zuerich (Switzerland); Harzenmoser, M.; Neuenschwander, J. [Swiss Federal Labs. for Materials Testing and Research, Duebendorf (Switzerland)] [Swiss Federal Labs. for Materials Testing and Research, Duebendorf (Switzerland); Wittgenstein, F. [CERN, Geneva (Switzerland)] [CERN, Geneva (Switzerland)

1996-07-01

151

Characteristics of electric parameters in aluminium alloy MAO coating process  

Microsoft Academic Search

Characteristics of electric parameters in the microarc oxidation (MAO) process of aluminium alloy at constant voltage were studied by a homemade data collecting system. The experimental results show that (1) the variations of the cathodic and anodic current amplitudes and the effective working current reflect obviously five different stages in the course of treatment and (2) variations of the dynamic

B H Long; H H Wu; B Y Long; J B Wang; N D Wang; X Y Lü; Z S Jin; Y Z Bai

2005-01-01

152

Recent development in aluminium alloys for the automotive industry  

Microsoft Academic Search

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

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

2000-01-01

153

Thermal dissociation of basic aluminium ammonium sulfate in vacuum  

Microsoft Academic Search

The course of thermal decomposition of basic aluminium ammonium sulfate was investigated. Temperature ranges were established in which dehydration of the compound and liberation of ammonia and sulfur oxides take place. The presented scheme of thermal dissociation of the basic salt was based on the determination of the solid and gaseous products of the reaction.

J. Pysiak; Barbara Pacewska

1980-01-01

154

Modelling of contact and friction in aluminium extrusion  

Microsoft Academic Search

A physical model capable of predicting the friction and sticking\\/slipping lengths in the bearing channel during unlubricated aluminium extrusion processes is presented. The model takes into account the pressure build up in the extrusion direction in relation with the bearing–extrudate friction and how it will be influenced by die geometry such as die angle and bearing length. The results show

X. Ma; M. B. De Rooij; D. J. Schipper

2010-01-01

155

Stretch bending of aluminium extrusions for car bumpers  

Microsoft Academic Search

Stretch bending of two generic aluminium bumper sections are investigated experimentally and numerically. Six different stretch bending procedures, herein denoted tensile sequences, are studied. Laboratory tests are performed for one of these sequences, finding that the numerical model represents the observed behaviour satisfactorily. A sequence with constant tensile force during bending seems to be favourable with respect of cross-section deformations.

Arild H Clausen; Odd S Hopperstad; Magnus Langseth

2000-01-01

156

Local buckling of square thin-walled Aluminium extrusions  

Microsoft Academic Search

An experimental investigation has been carried out to study the local buckling behaviour of square thin-walled aluminium extrusions in alloy AA6060. The primary variables have been the temper and wall thickness of the extrusions. Furthermore, the classical Stowell theory for plates has been modified to take postbuckling strength into account. Good correlation between theory and the present test results and

M. Langseth; O. S. Hopperstad

1997-01-01

157

PERCOLATION AND SUPERCONDUCTIVITY IN ION-IMPLANTED ALUMINIUM FILMS (*)  

E-print Network

L-435 PERCOLATION AND SUPERCONDUCTIVITY IN ION-IMPLANTED ALUMINIUM FILMS (*) F. MEUNIER and P of Si and Ge in Al thin films at 8 K produces alloys exhibiting enhanced superconducting transition in the superconducting transition temperature Tc of several such alloys [2], [5], [6] : Josephson tunnelling

Boyer, Edmond

158

High strain rate compressive behaviour of aluminium alloy foams  

Microsoft Academic Search

The high strain rate compressive behaviour of two cellular aluminium alloys (Alulight and Duocel) has been investigated using the split Hopkinson pressure bar and direct impact tests. It is found that the dynamic behaviour of these foams is very similar to their quasi-static behaviour. The plateau stress is almost insensitive to strain rate, for strain rates ?? up to 5000s?1.

V. S. Deshpande; N. A. Fleck

2000-01-01

159

Review article Aluminium toxicity in plants: a review  

E-print Network

Review article Aluminium toxicity in plants: a review G.R. ROUTa, S. SAMANTARAYb, P. DASb* a Plant Biotechnology Division, Regional Plant Resource Centre, Bhubaneswar- 751 015, Orissa, India b Plant Physiology and Biochemistry Laboratory, Regional Plant Resource Centre, Bhubaneswar- 751 015, Orissa, India (Received 31 May

Paris-Sud XI, Université de

160

Deformation behaviour of aluminium single crystals in ultraprecision diamond turning  

Microsoft Academic Search

The physical properties of the machined layer of single crystal aluminium after diamond turning were assessed by X-ray diffraction (XRD) to demonstrate the nature and extent of the plastic deformation process that had occurred in the workpiece. In the range of depth of cut investigated, the microstrain was found to vary with the crystallography of the machined surface, whereas the

S. To; W. B. Lee

2001-01-01

161

Cathodic dissolution in the electrocoagulation process using aluminium electrodes.  

PubMed

All the authors working with aluminium electrodes in the electrocoagulation process have shown that a dissolution occurs at the cathode. This result cannot be explained by the electrochemical process in which only the anodes should be dissolved. The most probable reaction is a chemical attack by hydroxyl ions (generated during water reduction) on the aluminium cathode but nobody has proved it in the framework of the electrocoagulation process. So we are interested in determining what kind of reactions occurs at the cathode. For that, we have elaborated a batch pilot apparatus divided into two compartments, allowing measurement of gas formation taking place only in one compartment. The gases measurements were performed by mass spectrometry with helium as carrier gas. To validate our experimental protocol, the first experiments have been done with a stainless steel cathode: in this case, the results have indicated that the amount of created hydrogen is in good agreement with the values calculated using the second Faraday's law. The experiments realised with an aluminium cathode have shown that the hydrogen formation, in these conditions, was higher than those observed with the stainless steel cathode. All our investigations enable us to propose that with an aluminium cathode, hydrogen formation can be separated into two phenomena. The first one is due to an electrochemical reaction (water reduction), and the second one arises from a chemical reaction explaining the dissolution observed at the cathode. PMID:11256647

Picard, T; Cathalifaud-Feuillade, G; Mazet, M; Vandensteendam, C

2000-02-01

162

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

163

A First Principles Study of Substitutional Copper in Aluminium  

Microsoft Academic Search

This study aims to gain insight into the early stages of precipitation hardening by determining the energetics of atom replacement by first principles computations. Density functional theory calculations using the ABINIT code were performed to determine cohesive energies and the equilibrium lattice constants of aluminium and copper for the conventional face centred cubic structure of 4 atoms. These were extended

A. E. Smith; S. Homolya

2004-01-01

164

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

165

Internal friction in hydrogen-charged aluminium alloys  

Microsoft Academic Search

Measurements of the internal friction of aluminium alloys containing hydrogen have been made from 77 to 300 K at 35 kHz using a composite resonator technique. Perfection of a metallic bonding technique for the transducer-specimen composite produced background dampings which were typically of the order Q ? 10. Criteria which relied on measurements at harmonic frequencies were used to distinguish

M. Leger; G. R. Piercy

1981-01-01

166

Laser Ablation of Aluminium: Drops and Voids Johannes Roth1  

E-print Network

Laser Ablation of Aluminium: Drops and Voids Johannes Roth1 , Johannes Karlin1 , Christian Ulrich2 introduction to the process of laser ablation, its simulation by the molecular dynamics method, and results be simulated which form during laser ablation. Laser ablation is a process where material is removed from

Roth, Johannes

167

Roles of Organic Acid Anion Secretion in Aluminium Tolerance of Higher Plants  

PubMed Central

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

168

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.

169

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

170

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

171

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

PubMed Central

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

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

2013-01-01

172

A histological study of toxic effects of aluminium sulfate on rat hippocampus.  

PubMed

Aluminium has toxic effects on many organ systems of the human body. Aluminium toxicity also is a factor in many neurodegenerative diseases. We investigated changes in numbers of hippocampal neurons in rats exposed to aluminium using an optical fractionator and we investigated aluminium-induced apoptosis using the transferase mediated dUTP nick end labeling (TUNEL) assay. Twenty-four female rats were divided equally into control, sham and aluminium-exposed groups. The control group received no treatment. The two treatment groups were injected intraperitoneally with 1 ml 0.9% saline without (sham) and with 3 mg/ml aluminium sulfate every day for two weeks. Following the treatments, the brains were removed, the left hemisphere was used for hippocampal neuron counting using an optical fractionator and the right hemisphere was investigated using hippocampal TUNEL assay to determine the apoptotic index. The number of neurons in the stratum pyramidale of the hippocampus was significantly less in the aluminium group than in the control and sham groups; there was no significant difference between the control and sham groups. The apoptotic index also was significantly higher in the aluminium group than in the other two groups. We quantified the toxic effects of aluminium on the rat hippocampus and determined that apoptosis was the mechanism of aluminium-induced neuron death in the hippocampus. PMID:25314162

Çabu?, N; O?uz, E O; Tufan, A Ç; Ad?güzel, E

2015-02-01

173

Advanced generation of green conversion coatings for aluminium alloys  

NASA Astrophysics Data System (ADS)

Anticorrosive cerium based treatments have been proved as efficient green alternatives to those based on environmentally undesirable Cr(VI) compounds. Thus, full immersion in cerium salt solutions allows reaching similar protection level against aluminium alloys corrosion that chromates treatments. However, treatment time is too high for being considered in industrial applications. In this work, accelerated methods for obtaining cerium-rich conversion coatings on aluminium-magnesium alloys are proposed. The films developed have been characterised by SEM and EDS. These studies have revealed that the coatings have a mixed or heterogeneous nature, being composed of a layer of alumina covering the matrix, together with islands of cerium formed over the cathodic intermetallics that are present on the surface of the alloy. Furthermore, studies conducted employing electrochemical techniques indicate that the degree of protection provided by these coatings is several orders of magnitude superior to that achieved with other treatments.

Bethencourt, M.; Botana, F. J.; Cano, M. J.; Marcos, M.

2004-11-01

174

Longitudinal study of workers of an aluminium die casting factory.  

PubMed

We conducted a 5-year longitudinal study on 76 workers of a high and medium aluminium alloy die-casting factory. As in a previous cross-sectional study conducted in 1986 and in accordance with the data in the literature, the 1990 follow-up study showed: a low prevalence of chronic bronchitis (as defined by the ECSC questionnaire on respiratory symptoms); normal mean functional values of FVC, FEV1, FEV1/FVC%. We did not find any significant difference in the levels of lung function over the period of 1986-90. These results show that workers in the secondary aluminium industry are not exposed to a significant risk of chronic pulmonary disease. PMID:1297059

Discalzi, G L; Capellaro, F; Baracco, A

1992-01-01

175

Patterned anodic aluminium oxide fabricated with a Ta mask  

NASA Astrophysics Data System (ADS)

Electrochemical anodization was applied to an aluminium (Al) sheet patterned with a metallic tantalum (Ta) mask, which gave rise to the formation of patterned anodic aluminium oxide (AAO). The morphological evolution of the AAO porous structure with anodizing time was characterized by scanning electron microscopy. Lateral anodizing of the Al sheet gradually developed underneath the metallic Ta mask with the increase of anodizing time. This has given us further understanding of the Al anodizing behaviour compared with our previous work with a SiO2 masked Al sheet. By controlling the anodizing time and the size of the metal mask, deep lithography of the Al substrate can be realized, and a mushroom-like Ta-Al microstructure with a high aspect ratio was created on the Al surface after removal of the AAO film. This Ta-Al microstructure has been studied in detail, and it was found to exhibit pronounced hydrophobic properties.

Zhao, Xiaowei; Jiang, Peng; Xie, Sishen; Feng, Jiafeng; Gao, Yan; Wang, Jianxiong; Liu, Dongfang; Song, Li; Liu, Lifeng; Dou, Xinyuan; Luo, Shudong; Zhang, Zengxing; Xiang, Yanjuan; Zhou, Weiya; Wang, Gang

2006-01-01

176

Aluminium in continuous ambulatory peritoneal dialysis and post dilutional hemofiltration.  

PubMed

Aluminium (Al) has been shown to be a constant contaminant of sterile apyrogenic solutions used in continuous ambulatory peritoneal dialysis (CAPD) or post dilutional hemofiltration (HF). The Al content of these solutions varied widely from 1 to 50 micrograms/l. The clinical significance of such an Al contamination was difficult to ascertain. However, the available information suggests little clinical toxicity from these low Al levels, except in those patients who ingest large amounts of aluminium hydroxide as a phosphate binder. In view of the well-known consequences of long-term Al exposure of dialysis patients, it is suggested that Al concentration in CAPD solutions and HF substitution fluids should not exceed 10 micrograms/l. PMID:3915962

Mion, C

1985-01-01

177

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

178

The research of properties of Eu3+-doped cadmium aluminium silicate glass  

NASA Astrophysics Data System (ADS)

We have prepared (40SiO2-14Al2O3-(40-x) CdO-2Li2O-2K2O-2Na2O -x Eu2O3) cadmium aluminium silicate glasses doped with europium by high temperature solid-state reaction method. The absorption spectra, excitation spectra, emission spectra are obtained. With the increase of Eu2O3, the absorption peaks are founded increasing to the best doped concentration and then reducing, which is nonlinear relationship. The charge-transfer band is moved to 320 nm due to the addition of Cd2+. We can see that the ratio of peak in 591 nm and 615 nm is 0.6-0.75 in general, and is unrelated to doped concentration. By changing concentration of Eu3+.We can adjust and mix different intensity of light according to the demand.

Chen, Yue-e.; Hou, Lan-tian; Song, Zhao-yuan

2008-11-01

179

Carbon-fibre-reinforced plastic (CFRP) strengthening of aluminium extrusions  

Microsoft Academic Search

The flexural behaviour of compound beams in which unidirectional carbon-fibre-reinforced plastic (CFRP) is externally bonded to extruded aluminium box-sections, is discussed. Simple transformed-section analysis and elastic buckling theory have been adapted to predict improvements in stiffness and strength with single-layer reinforcement. Close correlation between theory and experiment is observed and maximum gains in stiffness and ultimate strengths of 75% and

J. G. Broughton; A. Beevers; A. R. Hutchinson

1997-01-01

180

Anomalous creep behaviour of aluminium high current joint materials  

Microsoft Academic Search

During creep deformation the technical aluminium alloys EN AW-1350 (Al99.5) and EN AW-6060 (AlMgSi0.5) under certain conditions of stress and temperature show deformation thrusts of several millimetres, indicating discontinuous dynamic recrystallization. To study this anomalous creep behaviour in more detail the alloys were characterized by global and local texture measurements using neutron and electron backscatter diffraction (EBSD), respectively. In the

C.-G. Oertel; R. Tamm; W. Skrotzki; H.-G. Brokmeier

2005-01-01

181

Pin and bolt bearing strength of fibreglass\\/aluminium laminates  

Microsoft Academic Search

An experimental investigation was carried out on a fibreglass\\/aluminium (FGA) laminate in order to characterise its behaviour under pin- and bolt-bearing conditions. In pin bearing, the limit width-to-diameter and edge distance-to-diameter ratios necessary to avoid unsafe failure modes were lower than those usually quoted for classical laminates. A simple model to design safe pin-bearing joints, previously proposed for fibre-reinforced plastics,

G. Caprino; A. Squillace; G. Giorleo; L. Nele; L. Rossi

2005-01-01

182

Intermetallic compound layer growth between solid iron and molten aluminium  

Microsoft Academic Search

The interaction between solid iron and liquid aluminium is studied by immersion tests. At first, the intermetallic layers formed at the solid–liquid interface and their growth mechanisms are characterized. The Fe2Al5 and FeAl3 phases are identified in the temperature range from 700 to 900°C, and their growth is found to be mainly controlled by a diffusion regime. Then, a theoretical

K. Bouché; F. Barbier; A. Coulet

1998-01-01

183

The chemical transformation of copper in aluminium oxide during heating  

Microsoft Academic Search

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

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

2004-01-01

184

Adhesion between LDPE and hydrated aluminium in extrusion-coated laminates  

Microsoft Academic Search

Untreated aluminium and aluminium hydrated for 60 s in boiling water have been extrusion-coated with low-density polyethylene (LDPE). The hydration transforms the oxide surface into a porous oxyhydroxide, known as pseudoboehmite. LDPE samples with different melt indices (4.5, 7.5, and 15) were used, which influence the ability to penetrate into the pores. Compared with untreated aluminium, a superior peel strength

Anders Strålin; Thomas Hjertberg

1993-01-01

185

Effects of aluminium exposure on brain glutamate and GABA systems: an experimental study in rats  

Microsoft Academic Search

It has been postulated that the neurotoxic effects of aluminium could be mediated through glutamate, an excitatory amino acid. Hence the effects of aluminium administration (at a dose of 4.2mg\\/kg body weight daily as aluminium chloride, hexahydrate, intraperitoneally, for 4 weeks) on glutamate and ?-amino butyrate (GABA), an inhibitory amino acid, and related enzyme activities in different regions of the

P Nayak; A. K Chatterjee

2001-01-01

186

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.

2014-08-01

187

Spectroscopic diagnostics of plasma during laser processing of aluminium  

NASA Astrophysics Data System (ADS)

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

Lober, R.; Mazumder, J.

2007-10-01

188

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

189

Do aluminium-based phosphate binders continue to have a role in contemporary nephrology practice?  

PubMed Central

Background Aluminium-containing phosphate binders have long been used for treatment of hyperphosphatemia in dialysis patients. Their safety became controversial in the early 1980's after reports of aluminium related neurological and bone disease began to appear. Available historical evidence however, suggests that neurological toxicity may have primarily been caused by excessive exposure to aluminium in dialysis fluid, rather than aluminium-containing oral phosphate binders. Limited evidence suggests that aluminium bone disease may also be on the decline in the era of aluminium removal from dialysis fluid, even with continued use of aluminium binders. Discussion The K/DOQI and KDIGO guidelines both suggest avoiding aluminium-containing binders. These guidelines will tend to promote the use of the newer, more expensive binders (lanthanum, sevelamer), which have limited evidence for benefit and, like aluminium, limited long-term safety data. Treating hyperphosphatemia in dialysis patients continues to represent a major challenge, and there is a large body of evidence linking serum phosphate concentrations with mortality. Most nephrologists agree that phosphate binders have the potential to meaningfully reduce mortality in dialysis patients. Aluminium is one of the cheapest, most effective and well tolerated of the class, however there are no prospective or randomised trials examining the efficacy and safety of aluminium as a binder. Aluminium continues to be used as a binder in Australia as well as some other countries, despite concern about the potential for toxicity. There are some data from selected case series that aluminium bone disease may be declining in the era of reduced aluminium content in dialysis fluid, due to rigorous water testing. Summary This paper seeks to revisit the contemporary evidence for the safety record of aluminium-containing binders in dialysis patients. It puts their use into the context of the newer, more expensive binders and increasing concerns about the risks of calcium binders, which continue to be widely used. The paper seeks to answer whether the continued use of aluminium is justifiable in the absence of prospective data establishing its safety, and we call for prospective trials to be conducted comparing the available binders both in terms of efficacy and safety. PMID:21569446

2011-01-01

190

Dietary Exposure to Aluminium and Health Risk Assessment in the Residents of Shenzhen, China  

PubMed Central

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

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

2014-01-01

191

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

PubMed

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

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

2014-01-01

192

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

193

Effects of surface modification on the interfacial chemical stability and strength of continuous SiC fibres after exposure to molten aluminium  

Microsoft Academic Search

High strength and chemically compatible bilayer TiC\\/C-coated SiC fibers have been successfully developed. These high strength coated fibers improve the fiber wettability and protect the reinforcement against degradation when in contact with molten Al. In addition, the adhesion of TiC\\/C coatings to both SiC fibers and aluminium matrix appears to be good. Therefore the coating system can provide effective load

K. L. Choy

1995-01-01

194

Adsorption of ammonia on graphite oxide/aluminium polycation and graphite oxide/zirconium-aluminium polyoxycation composites.  

PubMed

Graphite oxide (GO) synthesized from commercial graphite was modified with aluminium or zirconium-aluminium polyoxycations and then calcined at 350 degrees C. On the samples obtained adsorption of ammonia from moist air was investigated. The surface of materials before and after exposure to ammonia was characterized using adsorption of nitrogen, XRD, SEM, FTIR, TA, CHN analysis, and potentiometric titration. The results showed that in spite of the fact that graphite composites/pillared graphites (PG) have Keggin-like ions located between the layers, that space blocked for nitrogen molecules used to determine the specific surface area. During calcinations, the deflagration of layers occurred as a result of decomposition of epoxy groups. This results in formation of disordered graphitic carbons with some mesoporosity. Even though these materials were not porous, the significant amount of ammonia was retained on the surface. Since ammonia molecule is able to specifically interact with oxygen groups of graphite oxide and Brønsted centers of inorganic pillars, it is likely intercalated between the composite layers. While the best performance was found for GO modified with aluminium-zirconium species, after calcinations the samples containing Keggin Al(13) like cations revealed the high capacity which is linked to the high acidity of incorporated inorganic compounds. PMID:18501918

Seredych, Mykola; Bandosz, Teresa J

2008-08-01

195

The influences of gypsum water-proofing additive on gypsum crystal growth  

Microsoft Academic Search

The gypsum water-proofing additives were composed of organic emulsion that were emulsified by polyvinyl alcohol and stearic acid and saline water-proofing additive made of alunite, carboxylic acid sodium, aluminium sulfate, etc. Using modern testing instrument, such as SEM, EPS, the influences of gypsum water-proofing additives on the crystal growth of gypsum products and its water-proof mechanism were analyzed from the

Jianquan Li; Guozhong Li; Yanzhen Yu

2007-01-01

196

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

NASA Astrophysics Data System (ADS)

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

Poková, M.; Cieslar, M.

2014-08-01

197

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

NASA Astrophysics Data System (ADS)

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

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

2002-01-01

198

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.

199

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

200

Measurement and modelling of the thermal conductivity of dispersed aluminium composites  

Microsoft Academic Search

Measurements of the thermal conductivity of a model system (squat aluminium cylinders suspended in an aqueous carbohydrate polymer gel) have been performed for a range of compositions up to the packing factor limit of the aluminium (approximately 0.6). Of a variety of models considered, the Cheng–Vachon model provided the most accurate predictions of thermal conductivity, and it was argued that

James K. Carson

2011-01-01

201

A cluster of equine granulomatous enteritis cases: the link with aluminium.  

PubMed

A cluster of 6 cases of equine granulomatous enteritis is described. Aluminium was demonstrated in the tissues and lesions of these horses and in the intimal bodies of intestinal vessels. The relationship between granulomatous lesions, aluminium, acidity and invading microorganisms, particularly parasites, is presented and discussed. PMID:9778770

Fogarty, U; Perl, D; Good, P; Ensley, S; Seawright, A; Noonan, J

1998-10-01

202

LA MESURE DU COD DES ALLIAGES D'ALUMINIUM ; DIFFICULTS RENCONTRES POUR SA DTERMINATION  

E-print Network

661 LA MESURE DU COD DES ALLIAGES D'ALUMINIUM ; DIFFICULTÉS RENCONTRÉES POUR SA DÉTERMINATION P vue de mesurer le COD d'alliages d'aluminium ont d'abord montré que les recommandations britanniques à balayage des surfaces de rupture ; elles ont montré que le COD est très différent suivant que l

Paris-Sud XI, Université de

203

FEM simulation of aluminium extrusion through two-hole multi-step pocket dies  

Microsoft Academic Search

Multi-hole pocket dies are a type of extrusion tooling setup commonly used across the aluminium extrusion industry for efficient production of solid aluminium profiles. Such dies are designed on the basis of experience and corrected after a number of trial extrusion runs before becoming usable. Computer simulation based on the finite element method (FEM) is in principle capable of predicting

Gang Fang; Jie Zhou; Jurek Duszczyk

2009-01-01

204

Wear of Inconel 718 die during aluminium extrusion—a case study  

Microsoft Academic Search

The wear analysis of an aluminium extrusion die made of Inconel 718 alloy has been performed. The highest degree of wear was observed in the middle of the contact surface with no or little wear in the adjoining regions. The wear mechanism was similar to that for steel dies and consisted in adhesive and abrasive modes. Strong adhesion of aluminium

Julia Gutovskaya; Jan Ketil Solberg; Hans Iver Lange; Lars Helge Andersen

2004-01-01

205

Local flange buckling and its relation to elastic springback in forming of aluminium extrusions  

Microsoft Academic Search

This paper presents a numerical and experimental investigation of interactions between local buckling and elastic springback in forming of thin-walled aluminium extrusions. The cross sectional distortions that are present in typical aluminium sections prior to elastic unloading cannot be disregarded. This is the case even when these beams are bent with relative large radii. The numerical analyses presented herein have

T. Welo; F. Paulsen

1996-01-01

206

Static and dynamic characteristics of a hybrid aluminium\\/composite drive shaft  

Microsoft Academic Search

A static torque and power transmission capacities of a hybrid aluminium\\/composite drive shaft, fabricated by a wetted filament winding method, were investigated. Special mechanisms for static torsion and power transmission test setups were designed and fabricated. The following different fibre types were used: carbon, glass, one epoxy, and hardener. The static and dynamic characteristic of the hybrid aluminium\\/composite drive shaft

S A Mutasher; B B Sahari; A M S Hamouda; S M Sapuan

2007-01-01

207

Anodization of evaporated aluminium on Ti6 wt% Al4 wt% V  

Microsoft Academic Search

Evaporated aluminium on Ti-6 wt% Al-4 wt% V alloy was anodized in phosphoric acid and other electrolytes. The anodic oxide formed was characterized by various techniques and it was found that a duplex oxide forms in which titanium has diffused through the aluminium oxide film and appears at the surface and throughout the film.

W. L. Baun; Wright-Patterson AFB

1980-01-01

208

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

209

Potentiometric determination of the 'formal' hydrolysis ratio of aluminium species in aqueous solutions.  

PubMed

The 'formal' hydrolysis ratio (h = C(OH-)added/C(Al)total) of hydrolysed aluminium-ions is an important parameter required for the exhaustive and quantitative speciation-fractionation of aluminium in aqueous solutions. This paper describes a potentiometric method for determination of the formal hydrolysis ratio based on an automated alkaline titration procedure. The method uses the point of precipitation of aluminium hydroxide as a reference (h = 3.0) in order to calculate the initial formal hydrolysis ratio of hydrolysed aluminium-ion solutions. Several solutions of pure hydrolytic species including aluminium monomers (AlCl3), Al13 polynuclear cluster ([Al13O4(OH)24(H2O)12]7+), Al30 polynuclear cluster ([Al30O8(OH)56(H2O)26]18+) and a suspension of nanoparticulate aluminium hydroxide have been used as 'reference standards' to validate the proposed potentiometric method. Other important variables in the potentiometric determination of the hydrolysis ratio have also been optimised including the concentration of aluminium and the type and strength of alkali (Trizma-base, NH3, NaHCO3, Na2CO3 and KOH). The results of the potentiometric analysis have been cross-verified by quantitative 27Al solution nuclear magnetic resonance (27Al NMR) measurements. The 'formal' hydrolysis ratio of a commercial basic aluminium chloride has been measured as an example of a practical application of the developed technique. PMID:18155411

Fournier, Agathe C; Shafran, Kirill L; Perry, Carole C

2008-01-21

210

Spot welding between aluminium alloy and low-carbon steel by friction stirring  

Microsoft Academic Search

The application of aluminium alloy, which is a typical lightweight material, has been expected in the construction of transportation vehicles to achieve energy saving by reduction of weight. However, structures made of whole aluminium alloy have problems with low strength and high cost. Thus, hybrid structures made of Al alloy and steel are useful because of light weight and higher

Katashi Miyagawa; Masami Tsubaki; Toshiaki Yasui; Masahiro Fukumoto

2009-01-01

211

Effect of aluminium doping on structural and gas sensing properties of zinc oxide thin films deposited by spray pyrolysis  

Microsoft Academic Search

A facile spray pyrolysis route is used to deposit aluminium doped ZnO (AZO) thin films on to the glass substrates. It is observed that on aluminium doping the particle size of ZnO reduces significantly; moreover, uniformity of particle also gets enhanced. Their XRD study reveals that intensity ratio of crystal planes depend on the aluminium doping concentration. The gas response

Satish S. Badadhe; I. S. Mulla

2011-01-01

212

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. PMID:9166127

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

1997-01-01

213

Aluminium control of argon solubility in silicate melts under pressure.  

PubMed

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

Bouhifd, M Ali; Jephcoat, Andrew P

2006-02-23

214

Wear behaviour of cast hypereutectic aluminium silicon alloys  

Microsoft Academic Search

In the present paper, influence of alloying elements on wear behaviour of binary (Al–17%Si) and multi-component (Al–17Si–0.8Ni–0.6Mg–1.2Cu–0.6Fe) cast hypereutectic aluminium alloys has been reported. Experimental alloys were prepared via foundry technique. Wear behaviour of Al–17Si and Al–17Si–X {X=Ni, Cu, Mg, Fe} alloys was studied using pin on disc (ASTM: G99) type of friction and wear testing machine. Dry sliding wear

Dheerendra Kumar Dwivedi

2006-01-01

215

Aluminium in Cars – 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 70’s 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.

2013-07-29

216

Foaming of aluminium-silicon alloy using concentrated solar energy  

SciTech Connect

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

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

2010-06-15

217

Absorbed aluminium is found with two cytosolic protein fractions, other than ferritin, in the rat duodenum.  

PubMed Central

After in vivo perfusion of the upper intestine of the rat with a range of concentrations of aluminium chloride, entry of the metal into the portal system was only detected when the perfusate exceeded 400 mumol/l, suggesting a mucosal block. Using gel filtration of a mucosal cytosol extract, two consistently appearing aluminium peaks were identified which may represent aluminium binding proteins. Both were heat stable at 60 degrees C and had molecular sizes of about 700 (kilo daltons) (kD) and 17 kD respectively. The larger molecule was distinct from ferritin. Neither molecule associated with 59Fe nor 45Ca. It is suggested that the aluminium peaks are relatively specific aluminium binding proteins that have a scavenging role, reducing entry of the metal from the intestinal contents into the portal blood. PMID:8504964

Cochran, M; Goddard, G; Ramm, G; Ludwigson, N; Marshall, J; Halliday, J

1993-01-01

218

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

219

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 a number of food contaminants, with the aim of 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 and assessments of intake of food additives (in particular, flavouring agents) and contaminants. A summary follows of the Committee's evaluations of technical, toxicological and intake data for certain food additives (annatto extracts, natamycin, propyl paraben, synthetic lycopene and lycopene from Blakeslea trispora and food contaminants (aluminium, 3-chloro-1,2-propanediol, 1,3-dichloro-2-propanol and methylmercury). Specifications for the following food additives were revised: carob bean gum, guar gum, titanium dioxide and zeaxanthin. Annexed to the report are tables summarizing the Committee's recommendations for intakes and toxicological evaluations of the food additives and contaminants considered. PMID:17687927

2007-01-01

220

Curcumin attenuates aluminium-induced functional neurotoxicity in rats.  

PubMed

Curcumin is a polyphenol extracted from the rhizome of Curcuma longa and well known as a multi-functional drug with antioxidative, anti-cancerous and anti-inflammatory activities. Curcumin's antiaging and neuroprotective potential is widely reported. In the present study, effect of curcumin treatment dose 30 mg kg(-1) day(-1) was investigated against aluminium neurotoxicity in young and old animals. Direct and indirect intakes of aluminium have been reported to be involved in the etiology of several neurodegenerative disorders like Alzheimer's and Parkinson's diseases. Long term Al was administered through drinking water at a dose of 50 mg/kg/day for 6 months in both young (4 months) and old (18 months) male Wistar rats. Result obtained demonstrates that curcumin treatment attenuates the Al-induced alterations at biochemical, behavioral and ultrastructural levels which was well reflected in the electrophysiological recordings. Our results indicate that curcumin's ability to bind redox active metals and cross the blood-brain barrier could be playing crucial role in preventing against Al-induced neurotoxicity. PMID:19376155

Sethi, Pallavi; Jyoti, Amar; Hussain, Ejaz; Sharma, Deepak

2009-07-01

221

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. PMID:22280884

2012-01-01

222

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

223

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. PMID:8563855

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

1996-01-01

224

Bacopa monniera prevents from aluminium neurotoxicity in the cerebral cortex of rat brain.  

PubMed

Bacopa monniera is a perennial herb, and is used as a nerve tonic in äyurveda, a traditional medicinal system in India. Aluminium-induced neurotoxicity is well known and different salts of aluminium have been reported to accelerate oxidative damage to biomolecules like lipids, proteins and nucleic acids. The objective of the present study was to investigate whether Bacopa monniera could potentially inhibit aluminium toxicity in the cerebral cortex. Male Wister rats (8 months old) were administered with AlCl(3) orally at a dose of 50mg/kg/day in drinking water for 1 month. Experimental rats were given AlCl(3) along with Bacopa monniera extract at a dose of 40 mg/kg/day. One group of rats was treated with l-deprenyl at a dose of 1mg/kg/day along with AlCl(3) treatment. We have observed that Bacopa monniera prevented accumulation of lipid and protein damage significantly, which resulted from aluminium intake. Decline in the activity of endogenous antioxidant enzymes associated with aluminium administration was also inhibited by Bacopa monniera extract. The potential of Bacopa monniera to inhibit Al-induced oxidative stress was observed to be similar to that of l-deprenyl, which was taken as standard. The potential of Bacopa monniera extract to prevent aluminium neurotoxicity was reflected at the microscopic level as well, indicative of its neuroprotective effects. These findings strongly implicate that Bacopa monniera has potential to protect brain from oxidative damage resulting from aluminium toxicity. PMID:17189676

Jyoti, Amar; Sethi, Pallavi; Sharma, Deepak

2007-04-20

225

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

PubMed

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

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

2015-01-01

226

Identification and estimation of extra-framework aluminium in acidic mazzite by diffuse reflectance spectroscopy.  

PubMed

Diffuse reflectance spectroscopy has been used to investigate structural modification of mazzite zeolite subjected to calcination, acid leaching and acetylacetone treatments. Extra-framework aluminium species, formed upon expulsion of aluminium from the framework, are detected by DRS because they are involved in aluminium-oxygen charge transfer transitions. Impregnation of the calcined ammonium-exchanged and acid leached samples with ethanolic acetylacetone will convert the broadened 260-280 nm band of extra-framework aluminium with distorted symmetry to a distinct well-defined 285 nm band. The appearance of this band is due to the transformation of the aluminium atoms with a different coordination number to structures with highly ordered octahedral symmetry. Washing the acetylacetone treated samples with hot ethanol leads to extraction of some of the complexed aluminium. The presence of an extracted aluminium triacetylacetonate complex in the eluant is verified by the same spectrophotometer used in its conventional mode. This suggests that a dual DR and UV-VIS spectrophotometry is an appropriate approach to study such topics. PMID:11209853

Zanjanchi, M A; Razavi, A

2001-01-01

227

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

228

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

NASA Astrophysics Data System (ADS)

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

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

2010-07-01

229

Aluminium adjuvants and adverse events in sub-cutaneous allergy immunotherapy  

PubMed Central

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

2014-01-01

230

Deformation mechanisms in ARB processed aluminium alloy AA6016 at low temperatures  

NASA Astrophysics Data System (ADS)

The deformation behaviour of the aluminium alloy AA6016 at low temperatures was investigated in the initial state and after 4 and 8 cycles of accumulative roll bonding (ARB). Tensile tests at 25 K, 77 K, 180 K and 296 K were performed at constant strain rate 10-4 s-1. Stress relaxation experiments performed during the tensile tests were used to determine the experimental rate sensitivity ? as a function of the flow stress ?. In all cases ? (?) is found to be linear revealing that the Cottrell-Stokes law holds. The effect of grain size on ? can be adequately described through an additive athermal stress contribution ?d, which is the higher the higher the degree of pre-deformation is. Moreover, the temperature dependence of the strain rate sensitivity m(T) indicates that the rate controlling mechanism in the initial state is local single slip. The ARB states deviate from the single slip behaviour already at 25 K. The reason probably is the occurrence of additional thermally activated slip processes in the ARB states.

Hollang, L.; Scharnweber, J.; Reuther, K.; Skrotzki, W.

2010-07-01

231

Cobalt and Nickel Nanopillars on Aluminium Substrates by Direct Current Electrodeposition Process  

PubMed Central

A fast and cost-effective technique is applied for fabricating cobalt and nickel nanopillars on aluminium substrates. By applying an electrochemical process, the aluminium oxide barrier layer is removed from the pore bottom tips of nanoporous anodic alumina templates. So, cobalt and nickel nanopillars are fabricated into these templates by DC electrodeposition. The resulting nanostructure remains on the aluminium substrate. In this way, this method could be used to fabricate a wide range of nanostructures which could be integrated in new nanodevices. PMID:20596338

2009-01-01

232

The aluminium content of breast tissue taken from women with breast cancer.  

PubMed

The aetiology of breast cancer is multifactorial. While there are known genetic predispositions to the disease it is probable that environmental factors are also involved. Recent research has demonstrated a regionally specific distribution of aluminium in breast tissue mastectomies while other work has suggested mechanisms whereby breast tissue aluminium might contribute towards the aetiology of breast cancer. We have looked to develop microwave digestion combined with a new form of graphite furnace atomic absorption spectrometry as a precise, accurate and reproducible method for the measurement of aluminium in breast tissue biopsies. We have used this method to test the thesis that there is a regional distribution of aluminium across the breast in women with breast cancer. Microwave digestion of whole breast tissue samples resulted in clear homogenous digests perfectly suitable for the determination of aluminium by graphite furnace atomic absorption spectrometry. The instrument detection limit for the method was 0.48 ?g/L. Method blanks were used to estimate background levels of contamination of 14.80 ?g/L. The mean concentration of aluminium across all tissues was 0.39 ?g Al/g tissue dry wt. There were no statistically significant regionally specific differences in the content of aluminium. We have developed a robust method for the precise and accurate measurement of aluminium in human breast tissue. There are very few such data currently available in the scientific literature and they will add substantially to our understanding of any putative role of aluminium in breast cancer. While we did not observe any statistically significant differences in aluminium content across the breast it has to be emphasised that herein we measured whole breast tissue and not defatted tissue where such a distribution was previously noted. We are very confident that the method developed herein could now be used to provide accurate and reproducible data on the aluminium content in defatted tissue and oil from such tissues and thereby contribute towards our knowledge on aluminium and any role in breast cancer. PMID:23870171

House, Emily; Polwart, Anthony; Darbre, Philippa; Barr, Lester; Metaxas, George; Exley, Christopher

2013-10-01

233

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

234

Anisotropic behaviour law for sheets used in stamping: A comparative study of steel and aluminium  

E-print Network

For a car manufacturer, reducing the weight of vehicles is an obvious aim. Replacing steel by aluminium moves towards that goal. Unfortunately, aluminium's stamping numerical simulation results are not yet as reliable as those of steel. Punch-strength and spring-back phenomena are not correctly described. This study on aluminium validates the behaviour law Hill 48 quadratic yield criterion with both isotropic and kinematic hardening. It is based on the yield surface and on associated experimental tests (uniaxial test, plane tensile test, plane compression and tensile shearing).

Jean-Jacques Sinou; Bruno Macquaire

2008-01-19

235

Aluminium coated carbon nanotube film for wavelength-selective surface  

NASA Astrophysics Data System (ADS)

We report selective optical reflectance in an aluminium (Al) coated flexible carbon nanotube (CNT) thin film over a wide range of wavelengths (500-2500 nm). Selective-wavelength surface is achieved by coating CNT surfaces with Al thin film that presented a maximum optical reflectivity of ˜65% in the infrared region. However, CNT film alone showed a reflectance of 15-20% over a larger range of wavelengths without any structural modification, which has not been realized so far. Moreover, a tailorable reflectance in CNT is shown to be achieved by tuning various parameters, namely, the porosity of the material, angle of an incident light, and refractive index of the materials. Owing to higher infrared reflectivity and thermal diffusivity, Al coated CNT presents a potential for a high efficiency solar collector.

Mukherjee, S.; Suri, A.; Vani, V. K.; Misra, A.

2013-09-01

236

Frictional conditions between alloy AA6060 aluminium and tool steel  

NASA Astrophysics Data System (ADS)

The frictional conditions in the new process of screw extrusion of aluminium have been investigated. The contact behaviour between the aluminum alloy and the tool steel in the extruder is vital for understanding the extrusion process. Using a compressive-rotational method for frictional measurements the conditions for unlubricated sticking friction between aluminum alloy AA6060 and tool steel at different combinations of temperatures and pressures have been investigated. In this method the samples in the form of disks are put under hydrostatic pressure while simultaneously being rotated at one end. Pins made from contrast material have been inserted into the samples to measure the deformation introduced. This approach along with 3D simulations form a method for determining the frictional conditions. The paper describes the test method and the results. It was found that the necessary pressure for sticking to occur between the aluminum AA6060 and the different parts of the extruder is heavily influenced by the temperature.

Widerøe, Fredrik; Welo, Torgeir

2011-05-01

237

Optimization of Aluminium-to-Magnesium Ultrasonic Spot Welding  

NASA Astrophysics Data System (ADS)

The ability to join dissimilar materials in the automotive industry will result in more efficient multimaterial structures. However, welding of aluminium (Al) to magnesium (Mg) alloys is problematic because of the rapid formation of brittle intermetallic phases at the weld interface. Ultrasonic welding (USW) is a solid-state joining technology that may offer a potential solution, but USW of Al to Mg is currently not well understood. Here, we have investigated the effect of process variables and energy input on joint formation between Al-6111 and Mg-AZ31 alloys, and we report on the optimum welding conditions, heat generation, and the formation of a significant intermetallic reaction layer. Furthermore, the factors influencing the interface reaction rate and the advantages of precoating the Mg with Al are discussed.

Panteli, A.; Chen, Y.-C.; Strong, D.; Zhang, Xiaoyun; Prangnell, P. B.

2012-03-01

238

Thermodynamic modelling of growth-restriction effects in aluminium alloys  

SciTech Connect

The amount and type of alloying elements in aluminium affect the as-cast microstructure through the dependence of solidified fraction on undercooling. This can be quantified by the growth-restriction parameter Q. Phase-diagram calculations using the CALPHAD method show the effects of thermodynamic parameters on Q. In binary systems, the deviation from linear dependence of Q on solute concentration is assessed. In ternary alloys, model systems elucidate the role of solute interaction in the liquid and solid, and can be used to interpret the behaviour in actual systems. Growth restriction is discussed in relation to solidification modelling and the attainment of a fine, equiaxed microstructure in wrought and shape-casting alloys.

Quested, T.E. [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ (United Kingdom)]. E-mail: teq20@cam.ac.uk; Dinsdale, A.T. [National Physical Laboratory, Queens Road, Teddington, Middlesex TW11 0LW (United Kingdom); Greer, A.L. [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ (United Kingdom)

2005-03-01

239

Frictional conditions between alloy AA6060 aluminium and tool steel  

SciTech Connect

The frictional conditions in the new process of screw extrusion of aluminium have been investigated. The contact behaviour between the aluminum alloy and the tool steel in the extruder is vital for understanding the extrusion process. Using a compressive-rotational method for frictional measurements the conditions for unlubricated sticking friction between aluminum alloy AA6060 and tool steel at different combinations of temperatures and pressures have been investigated. In this method the samples in the form of disks are put under hydrostatic pressure while simultaneously being rotated at one end. Pins made from contrast material have been inserted into the samples to measure the deformation introduced. This approach along with 3D simulations form a method for determining the frictional conditions. The paper describes the test method and the results. It was found that the necessary pressure for sticking to occur between the aluminum AA6060 and the different parts of the extruder is heavily influenced by the temperature.

Wideroee, Fredrik; Welo, Torgeir [Norwegian University of Science and Technology-Dept. of Engineering Design and Materials-Norway (Norway)

2011-05-04

240

Ultrafine particles at workplaces of a primary aluminium smelter.  

PubMed

The number concentration and size distribution of ultrafine particles in a Søderberg and a prebake potroom of an aluminium primary smelter have been measured using a scanning mobility particle spectrometer. The particle morphology was studied by transmission electron microscopy (TEM). The study shows the existence of elevated number concentrations of ultrafine particles in both potrooms. The main source of these particles is likely to be the process of anode changing. The ultrafine particles were measured directly at the source but could also be identified as episodes of high number concentrations in the general background air. Unlike the larger particles belonging to the 50-100 nm mode, the nanoparticle mode could not be detected in the TEM indicating that they may not be stable under the applied sampling conditions and/or the high vacuum in the instrument. PMID:16395469

Thomassen, Yngvar; Koch, Wolfgang; Dunkhorst, Wilhelm; Ellingsen, Dag G; Skaugset, Nils-Petter; Jordbekken, Lars; Arne Drabløs, Per; Weinbruch, Stephan

2006-01-01

241

Pico- and nanosecond laser ablation of mixed tungsten / aluminium films  

E-print Network

In order to extend the investigation of laser-assisted cleaning of ITER-relevant first mirror materials to the picosecond regime, a commercial laser system delivering 10 picosecond pulses at 355 nm at a frequency of up to 1 MHz has been used to investigate the ablation of mixed aluminium (oxide) / tungsten (oxide) layers deposited on poly- and nanocrystalline molybdenum as well as nanocrystalline rhodium mirrors. Characterization before and after cleaning using scanning electron microscopy (SEM) and spectrophotometry shows heavy dust formation, resulting in a degradation of the reflectivity. Cleaning using a 5 nanosecond pulses at 350 and 532 nm, on the other hand, proved very promising. The structure of the film remnants suggests that in this case buckling was the underlying removal mechanism rather than ablation. Repeated coating and cleaning using nanosecond pulses is demonstrated.

Wisse, M; Steiner, R; Mathys, D; Stumpp, A; Joanny, M; Travere, J M; Meyer, E

2014-01-01

242

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

PubMed

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

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

2005-03-01

243

AlVis An AluminiumFoam Visualization and Investigation Tool  

E-print Network

interesting properties for the application of aluminium foam (e.g. car manufacturing). Material scientists the complex structure of the metal foam. Keywords: aluminum foam investigation, surface extraction #12; 1

244

Selection of aluminium alloys for extrusion profiles: methodology and development of a specialised software  

Microsoft Academic Search

Material selection methods are applied to the selection of extruded aluminium alloys components. The competition between materials cost and processing cost in relation to materials extrudability and shape complexity is investigated. A tailored software for industrial purposes has been developed.

G Heiberg; Y Brechet; O Jensrud; H. J Roven

2002-01-01

245

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

NASA Astrophysics Data System (ADS)

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

Revel, Renaud; Audichon, Thomas; Gonzalez, Serge

2014-12-01

246

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

PubMed

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 (TiCl(4), BiCl(3), InCl(3) or PbCl(2)) 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. PMID:21124514

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

2010-04-01

247

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

248

X-ray analysis of Pt?Sn catalysts supported on zinc-aluminium spinel  

Microsoft Academic Search

An x-ray diffraction analysis of Pt?Sn catalysts supported on zinc-aluminium spinel has shown that, after testing in paraffin dehydrogenation, they contain a tin-platinum solid solution with a face-centered cubic cell.

E. M. Moroz; N. A. Pakhomov; G. R. Kotelnikov; R. A. Buyanov; V. A. Patanov

1977-01-01

249

Degradation of unglazed rough graphite-aluminium solar absorber surfaces in simulated acid and neutral rain  

Microsoft Academic Search

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

P. Konttinen; T. Salo; P. D. Lund

2005-01-01

250

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

Microsoft Academic Search

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

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

251

Simulation and Characterization of Aluminium Three-Dimensional Resonator for Quantum Computation  

NASA Astrophysics Data System (ADS)

We present the simulation and characterization of several aluminium three-dimensional (3D) resonators, which can be used for superconducting quantum computation. By changing the conductivity of the aluminium in a high frequency structure simulator, the loaded quality factor at room temperature and base temperature (20mK) can be simulated. From S21 measurement, we can characterize the properties of the resonators. The simulated and experimental results can be fitted well by exponential equations.

Zhao, Hu; Li, Tie-Fu; Liu, Qi-Chun; Liu, Jian-She; Chen, Wei

2014-10-01

252

Fatigue properties of friction stir welded particulate reinforced aluminium matrix composites  

Microsoft Academic Search

Few papers have discussed the friction stir welding (FSW) of particulate reinforced aluminium matrix composites and most of them focused on the set-up of the welding process parameters and their effect on microstructure, hardness and tensile behaviour. The aim of this study was to investigate the fatigue resistance of FSW joints on an as-cast particulate reinforced aluminium based composite (AA6061\\/22vol.%\\/Al2O3p).

G. Minak; L. Ceschini; I. Boromei; M. Ponte

2010-01-01

253

Fatigue and fatigue crack growth of aluminium alloys at very high numbers of cycles  

Microsoft Academic Search

The application of ultrasonic frequency (20kHz) loading to test fatigue and fracture mechanical properties of materials is briefly reviewed and recent investigations on high strength aluminium alloys are reported. Very high cycle endurance tests and near threshold crack growth experiments were performed with the 2024-T351 aluminium alloy. Lifetimes are approximately 10–100 times lower, if cycled in distilled water instead of

S. E. Stanzl-Tschegg; H. Mayer

2001-01-01

254

Pulmonary disease from occupational exposure to an artificial aluminium silicate used for cat litter  

Microsoft Academic Search

All available workers engaged in bagging an artificial crystalline aluminium silicate--the kiln-dried residue from the calcining and water extraction of alunite (a hydrated sulphate of aluminium and potassium) that is currently classified as a nuisance dust--were studied after a complaint of respiratory and systemic symptoms, including arthritis, by an employee of the factory, who showed physiological and radiographic evidence of

A W Musk; H W Greville; A E Tribe

1980-01-01

255

Aluminium speciation in natural water by sorption on a complexing resin.  

PubMed

Very stable aluminium complexes may be present in natural waters, which can be detected only using appropriate methods. One of them is the resin titration based on the sorption of aluminium on a strongly sorbing resin, Chelex 100. It was here used to detect strong aluminium complexes, and to characterize them by determining their concentration, and the corresponding stability constant. High and low salinity waters were sampled in different sites in the North of Italy. In all the samples aluminium complexes with high stability constant, up to 10(17.4) M(-1) in the less acidic solution, were detected. The stability constant depends mainly on the solution acidity, increasing with increasing pH up to 7. The concentration of the ligands responsible for the strong complexation is similar to that of aluminium (from 0.5 to 1.5 microM), or somewhat lower in the case of estuarine and sea waters. A small fraction of aluminium (from 0% to 2%) in freshwaters, higher in estuarine and sea waters (14% and 10%, respectively), is present in weakly bound forms which could also be the hydrolysis products. The conditional constants of the strong complexes were determined for the different samples examined. They were found to be slightly lower in the case of the high salinity waters, in which a value of 10(16.1) M(-1) at pH 7.5 was obtained. This is probably due to the higher ionic strength in marine water, which strongly influences the complexation of trivalent metal ions, as seen for example also in the hydrolysis. It could be deduced that similar substances, but at different concentration, would be responsible for the aluminium complexation in the sea and freshwaters here examined. They could be natural organics like fulvic substances, or better some particular complexing sites in this substances with very high affinity for aluminium. PMID:16055193

Alberti, G; D'Agostino, G; Palazzo, G; Biesuz, R; Pesavento, M

2005-09-01

256

Welding of aluminium alloys with high-power Nd:YAG lasers  

Microsoft Academic Search

The use of aluminium and its alloys is increasing, particularly in the transport industry. However, weldability is poorer than in other materials and their properties are reduced due to loss of alloying elements and\\/or heat treatment. A brief overview is given of the use of high-power Nd: YAG lasers in welding aluminium alloys and the results of combining high-power beams

J. A. Ga-Orza

1999-01-01

257

Naturally occurring radioactive material from the aluminium industry--a case study: the Egyptian Aluminium Company, Nag Hammady, Egypt.  

PubMed

The activity concentrations and the gamma-absorbed dose rates of the terrestrial naturally occurring radionuclides (226)Ra and (232)Th were determined in samples of bauxite, alumina and aluminium dross tailings industrial waste (used to produce two types of alums) using high purity germanium (HPGe) gamma ray spectrometry. The bauxite and alumina are imported by Egyptalum (The Egyptian Aluminium Company, Nag Hammady, Egypt) from Guinea and India. The activity concentrations in the bauxite range from 29 +/- 1 to 112 +/- 6 Bq kg(-1) for (226)Ra, and 151 +/- 8 to 525 +/- 12 Bq kg(-1) for (232)Th, with mean values of 62 +/- 8 and 378 +/- 50 Bq kg(-1), respectively. With respect to alumina and tail, the mean values are 5.7 +/- 1.1 and 8.4 +/- 0.8 Bq kg(-1) for (226)Ra and 7.2 +/- 1.6 and 10.7 +/- 1.2 Bq kg(-1) for (232)Th. Potassium-40 was not detected in any of the studied samples. The measured activity concentrations of (226)Ra and (232)Th in bauxite are higher than the world average while in alumina and tail they are lower. As a measure of radiation hazard to the occupational workers and members of the public, the Ra equivalent activities and external gamma dose rates due to natural radionuclides at 1 m above the ground surface were calculated. The external gamma-radiation doses received by the Egyptalum workers are 97, 409, 8.5 and 12.7 microSv y(-1) for the Guinean and Indian bauxite, the alumina and tail, respectively, which is well below the recommended allowed dose of 1 mSv y(-1) for non-exposed workers. PMID:17146126

Abbady, Adel G E; El-Arabi, A M

2006-12-01

258

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

259

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

260

The role of arbuscular mycorrhizas in decreasing aluminium phytotoxicity in acidic soils: a review.  

PubMed

Soil acidity is an impediment to agricultural production on a significant portion of arable land worldwide. Low productivity of these soils is mainly due to nutrient limitation and the presence of high levels of aluminium (Al), which causes deleterious effects on plant physiology and growth. In response to acidic soil stress, plants have evolved various mechanisms to tolerate high concentrations of Al in the soil solution. These strategies for Al detoxification include mechanisms that reduce the activity of Al3+ and its toxicity, either externally through exudation of Al-chelating compounds such as organic acids into the rhizosphere or internally through the accumulation of Al-organic acid complexes sequestered within plant cells. Additionally, root colonization by symbiotic arbuscular mycorrhizal (AM) fungi increases plant resistance to acidity and phytotoxic levels of Al in the soil environment. In this review, the role of the AM symbiosis in increasing the Al resistance of plants in natural and agricultural ecosystems under phytotoxic conditions of Al is discussed. Mechanisms of Al resistance induced by AM fungi in host plants and variation in resistance among AM fungi that contribute to detoxifying Al in the rhizosphere environment are considered with respect to altering Al bioavailability. PMID:23328806

Seguel, Alex; Cumming, Jonathan R; Klugh-Stewart, Katrina; Cornejo, Pablo; Borie, Fernando

2013-04-01

261

Aluminium in the South Atlantic: Steady state distribution of a short residence time element  

SciTech Connect

The aluminium concentrations of water samples from 18 hydrographic profiles and 35 surface samples in the South Atlantic were determined on board ship during leg III of the South Atlantic Ventilation Experiment (SAVE). The observed surface water distributions (range 0.5 to 57 nM) are though to arise from the partial dissolution of eolian-transported continental dusts coupled with limited lateral transport by prevailing surface currents. In the deep water the greatest enrichments are observed coincident with the depth of the lower North Atlantic Deep Water. The similarity between the Al:Si ratios in this water mass in both the south and north Atlantic is taken as evidence that no significant Al additions are being made to this water during its transit. The lower Al concentrations observed in the water masses of Antarctic origin ({approximately} 3 nM) are consistent with their formation in areas of limited dust input. The somewhat higher values observed in the Antarctic Bottom Water suggest that the shelf component of this water mass may have elevated Al concentrations.

Measures, C.I.; Edmond, J.M. (Massachusetts Inst. of Tech., Cambridge (United States))

1990-04-15

262

Determining the aluminium occupancy on the active T-sites in zeolites using X-ray standing waves  

NASA Astrophysics Data System (ADS)

Zeolites are microporous crystalline materials that find wide application in industry, for example, as catalysts and gas separators, and in our daily life, for example, as adsorbents or as ion exchangers in laundry detergents. The tetrahedrally coordinated silicon and aluminium atoms in the zeolite unit cell occupy the so-called crystallographic T-sites. Besides their pore size, the occupation of specific T-sites by the aluminium atoms determines the performance of the zeolites. Despite its importance, the distribution of aluminium over the crystallographic T-sites remains one of the most challenging, unresolved issues in zeolite science. Here, we report how to determine unambiguously and directly the distribution of aluminium in zeolites by means of the X-ray standing wave technique using brilliant, focused X-rays from a third-generation synchrotron source. We report in detail the analysis of the aluminium distribution in scolecite, which demonstrates how the aluminium occupancy in zeolites can systematically be determined.

van Bokhoven, Jeroen A.; Lee, Tien-Lin; Drakopoulos, Michael; Lamberti, Carlo; Thieß, Sebastian; Zegenhagen, Jörg

2008-07-01

263

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

NASA Astrophysics Data System (ADS)

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

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

2011-01-01

264

Alternative Addition Strategies  

NSDL National Science Digital Library

This lesson explores recall of multiple alternative addition strategies of two-digit numbers. The lesson focus is to encourage students to use more than one strategy to solve addition problems. By reinforcing the multiple alternative addition strategies students will develop a strong understanding of addition structures and mechanics before moving on to three-digit addition. The lesson includes making an Addition Strategies Mini Booklet, which students can keep and use as a reference tool.

Judith Scapecchi

2012-07-31

265

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

266

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

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

267

Esophageal complications following aluminium phosphide ingestion: an emerging issue among survivors of poisoning.  

PubMed

Aluminium phosphide ingestion is the most common agricultural poisoning in suburban and rural India and with a high mortality rate. Among survivors of acute poisoning there are recent sporadic reports of esophageal complications such as esophageal strictures and tracheo-esophageal fistula. The present study was carried out to determine the incidence, natural history, and treatment outcome of local esophageal complications in survivors of aluminium phosphide poisoning with complaints of dysphagia. All confirmed cases of poisoning with aluminium phosphide ingestion were admitted in Hamidia Hospital, Gandhi Medical College, Bhopal, Madhya Pradesh, India, from October 2007 to October 2008. Survivors with complaints of dysphagia underwent a barium study and upper gastrointestinal endoscopy to determine site and nature of esophageal complications. All cases of strictures were treated with fluoroscopy-guided Savary-Gilliard bougie dilation, and patients with tracheo-esophageal fistula underwent surgery. Of 104 confirmed cases, 31 survived. Ten survivors with dysphagia were found to have single short-segment esophageal stricture and two patients with odynophagia and swallow-cough sequence had tracheo-esophageal fistula. All cases of esophageal strictures responded successfully to Savary-Gilliard dilation in six to ten sessions without any major complications. Patients with tracheo-esophageal fistula were treated successfully via surgery. Nearly one-third of survivors of aluminium phosphide ingestion developed esophageal complications. Hence, we conclude that all survivors of aluminium phosphide poisoning must undergo barium swallow and endoscopic examination for early detection of esophageal complications. Prevention of esophageal complications after aluminium phosphide ingestion needs to be given adequate attention because tracheo-esophageal fistula and esophageal stricture are associated with high morbidity. When one finds esophageal stricture or fistula, the possibility of aluminium phosphide ingestion should always be considered. PMID:19727954

Jain, Rajendra K; Gouda, Narendra B; Sharma, Virendra K; Dubey, Tribhuvan N; Shende, Atul; Malik, Rajesh; Tiwari, Gurudutt

2010-12-01

268

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

269

Evidence of superdense aluminium synthesized by ultrafast microexplosion.  

PubMed

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(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 (?-Al(2)O(3)). Confined microexplosions offer a strategy to create and recover high-density polymorphs, and a simple method for tabletop study of warm dense matter. PMID:21863012

Vailionis, Arturas; Gamaly, Eugene G; Mizeikis, Vygantas; Yang, Wenge; Rode, Andrei V; Juodkazis, Saulius

2011-01-01

270

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

271

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

272

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

273

Thorium sorption in seawater suspensions of aluminium oxide particles  

NASA Astrophysics Data System (ADS)

The partitioning of thorium between solid and solution phases in seawater suspensions of aluminium oxide particles was studied in controlled laboratory experiments to determine whether partitioning is consistent with current models of trace-metal adsorption (surface complexation models). Experimental conditions (i.e., thorium and particle concentrations, pH, temperature, salinity) were chosen to be as realistic as possible for coastal seawater while minimizing nonadsorptive processes; 234Th was used as a tracer of thorium, and filtration/ultrafiltration techniques were used to prepare suspensions with minimal colloidal material, as well as to define and to separate solid and solution phases. A comparison of the experimental results with relationships predicted by surface complexation models shows that thorium sorption in the alumina suspensions was consistent with surface complexation theory: Sorption kinetics were consistent with a (pseudo-) first-order reversible reaction at constant particle concentration, the pseudo-first-order forward rate constants had a first-order dependence on particle concentration, and Kd values were independent of particle concentration. Thorium sorption consisted of two distinct reversible reactions, both of which were consistent with surface complexation theory. Second order rate constants were within the range of rate constants reported for the adsorption of divalent metal ions onto?-Al 2O 3 surfaces.

Niven, Sherry E. H.; Moore, Robert M.

1993-05-01

274

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. PMID:24282332

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

2013-01-01

275

Free radical scavengers & lipid peroxidation in acute aluminium phosphide poisoning.  

PubMed

Free radicals scavengers superoxide dismuatase (SOD) and catalase and lipid peroxidation were studied in 45 patients of aluminium phosphide poisoning irrespective of age and sex admitted to a hospital in north India during the January 1992 to December 1993. Serial serum superoxide dismutase (SOD), catalase and MDA (malonyldialdehyde) were estimated on days 1, 2 and 5 post-admission depending on the survival of the patients. Serum SOD levels were significantly higher (P < 0.001) but serum catalase was significantly lower (P < 0.001) in patients than controls (patients of peripheral circulatory failure and normals) on days 1 and 2 which suggested stimulation of SOD and inhibition of catalase by phosphine resulting in excessive hydrogen peroxide (H2O2) load. Significantly higher levels of MDA (P < 0.001) in patients than controls on days 1 and 2 indicated enhanced lipid peroxidation in this poisoning. Twenty four patients died constituting a mortality rate of 53.3 per cent. The significantly high levels of SOD and MDA in non-survivors suggested their direct relation to mortality while catalase levels had an inverse relationship. Return of SOD and catalase and MDA to normal or near normal levels in survivors by day 5 suggested abolition of an oxidative stress due to elimination of phosphine. PMID:8840658

Chugh, S N; Arora, V; Sharma, A; Chugh, K

1996-08-01

276

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. PMID:22534883

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

2013-01-01

277

Heterometallic aluminates: alkali metals trapped by an aluminium aryloxide claw.  

PubMed

A series of heterometallic aluminium-alkali metal species [AlMMe2{2,6-(MeO)2C6H3O}2]n have been isolated for lithium, sodium and potassium. These compounds can be generated by the reaction of [AlMe2{2,6-(MeO)2C6H3O}]2 with the metallated phenol [M{2,6-(MeO)2C6H3O}]n or through the reaction of the mixture of AlMe3 and the appropriate alkali metal alkyl base with two equivalents of 2,6-dimethoxyphenol. In the heterometallic species obtained, the {AlMe2{2,6-(MeO)2C6H3O}2}(-) moiety is observed and could be described as a claw which fixes the alkali ion by the phenoxide oxygen atoms while the methoxy groups help to stabilize their coordination sphere. All compounds have been characterized by NMR spectroscopy and X-ray diffraction methods. Catalytic studies reveal that these compounds are active in ring-opening polymerization of L-lactide. PMID:24965205

Muñoz, M Teresa; Cuenca, Tomás; Mosquera, Marta E G

2014-10-14

278

Evidence of superdense aluminium synthesized by ultrafast microexplosion  

PubMed Central

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 104 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 (?-Al2O3). Confined microexplosions offer a strategy to create and recover high-density polymorphs, and a simple method for tabletop study of warm dense matter. PMID:21863012

Vailionis, Arturas; Gamaly, Eugene G.; Mizeikis, Vygantas; Yang, Wenge; Rode, Andrei V.; Juodkazis, Saulius

2011-01-01

279

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

PubMed

The combined and individual effects of aluminium and sulphate at concentrations of 1,000 mg/l as Al(OH)3, and 150 mgSO4(2-)/L as K2SO4, respectively, on the anaerobic digestion of sludge from enhanced primary treatment (EPT) were evaluated in 1 L capacity semi continuous reactors. It was found that at 59 days, aluminium inhibits the specific methanogenic activity (SMA) of methanogenic and acetogenic bacteria resulting in a 50% to 72% decrease. Sulphate also inhibits (48% to 65%) the SMA of the same type of bacteria. Methanogenic and acetogenic bacteria were able to adapt, to a different extent, to the assayed concentrations of aluminium and sulphate. However, the combination of aluminium and sulphate resulted in a higher inhibition, especially of the hydrogenophilic methanogenic bacteria. Indeed, this effect remained during the time of the experiment, maintaining an inhibition of 44% at 114 days. Feeding with EPT sludge led to a bigger decrease in SMA of each bacterial group, with respect to the other treatments with time. It is concluded that the acidification of anaerobic reactors fed with EPT sludge is due, among other causes, to the concurrent presence of aluminium and sulphate. PMID:14640223

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

2003-01-01

280

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

281

Tensile Strength and Hardness Correlations with Microscopy in Friction welded Aluminium to Copper  

NASA Astrophysics Data System (ADS)

Aluminium and copper are good conductors of heat and electricity, copper being the better conductor, is a costly metal indeed. On the other hand, aluminium is cheap, easily available and also has a lower density than copper. Hence, worldwide efforts are being made to partially replace copper wire. Solid state welding should be used to join aluminium to copper. This is because the use of fusion welding results in brittle phases formed in the weld interface. One of the solid state welding techniques used for joining aluminium to copper is friction welding. In this paper, an attempt has been made to join aluminium to copper by friction welding by varying the friction welding parameters, namely friction pressure, upset pressure, burn-off length and speed of rotation of the workpiece. Nine different friction welding parameter combinations were used during welding in accordance with ASTM standards and results have been reported. Tensile strength and hardness tests were carried out for each parameter combination. Optimum friction welding parameter combination was identified with respect to tensile strength. Scanning Electron Microscopy and Electron dispersive spectroanalysis were obtained to identify modes of fracture and presence of intermetallic phases for each friction welding combination with the aim to narrow down friction welding parameters that give good properties on the whole.

Satish, Rengarajan; Seshagiri Rao, Vaddi; Ananthapadmanaban, Dattaguru; Ravi, Balappa

2015-03-01

282

Modulatory Role of Simvastatin against Aluminium Chloride-Induced Behavioural and Biochemical Changes in Rats  

PubMed Central

Objectives. Aluminium, a neurotoxic agent in humans, has been implicated in the pathogenesis of neurodegenerative disorders. In this study, we examined the behavioral and biochemical effects of aluminium in rats with special emphasis on memory centres, namely, hippocampus and frontal cortex. Further, the effect of simvastatin treatment on aluminium intoxication was evaluated. Methods. Rats were exposed to aluminium chloride (AlCl3) for 60 days. Simvastatin (10?mg/kg/p.o.) and rivastigmine (1?mg/kg/p.o.) were administered daily prior to AlCl3. Behavioral parameters were assessed using Morris water maze test and actophotometer followed by biochemical investigations, namely, acetylcholinesterase (AChE) activity, TNF-? level, antioxidant enzymes (GSH, catalase), lipid peroxidation, and nitrite level in hippocampus and frontal cortex. Triglycerides, total cholesterol, LDL, and HDL levels in serum were also determined. Key Findings. Simvastatin treatment improved cognitive function and locomotor activity in rats. Simvastatin reversed hyperlipidemia and significantly rectified the deleterious effect of AlCl3 on AChE activity. Further, in hippocampus and frontal cortex, aluminium-induced elevation in nitrite and TNF-? and reduction in antioxidant enzymes were inhibited by simvastatin. Conclusion. To conclude, the present study suggests that simvastatin per se protects the neurons in hippocampus and frontal cortex from AlCl3, an environmental toxin. PMID:25802481

Nampoothiri, Madhavan; John, Jessy; Kumar, Nitesh; Mudgal, Jayesh; Nampurath, Gopalan Kutty; Chamallamudi, Mallikarjuna Rao

2015-01-01

283

Going Loopy for Addition  

NSDL National Science Digital Library

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

Tracey DeCloedt

2012-07-30

284

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

285

[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

286

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

287

Identification of AFLP and microsatellite markers linked with an aluminium tolerance gene in barley ( Hordeum vulgare L.)  

Microsoft Academic Search

Barley is the most sensitive among the cereals to aluminium (Al) stress and breeding for more tolerant cultivars is a priority. To enhance selection efficiency for Al tolerance in barley, PCR-based AFLP and microsatellite markers linked to a locus conferring tolerance to aluminium were identified. The study used F2 progeny derived from a single cross between Yambla (moderately tolerant of

H. Raman; J. S. Moroni; K. Sato; B. Read; B. Scott

2002-01-01

288

Potential for preventing spread of fungi in air-conditioning systems constructed using copper instead of aluminium  

Microsoft Academic Search

Aims: As copper has been previously suggested as an antimicrobial surface, we tested the effectiveness of copper as an antifungal surface which could be used in air-conditioning systems as an alternative to aluminium. Methods and Results: Coupons of copper (C11000) and aluminium were inoc- ulated with fungal isolates (Aspergillus spp., Fusarium spp., Penicillium chryso- genum and Candida albicans) for various

L. Weaver; H. T. Michels; C. W. Keevil

289

Formation of nano-sized alumina by in-flight oxidation of aluminium powder in a thermal plasma reactor  

Microsoft Academic Search

Nano-sized aluminium oxide powder has been synthesized in a thermal plasma reactor by in-flight oxidation of aluminium metal. The particle size of alumina formed ranges from a few nanometers to 30 nm. Experimental studies have been complemented by numerical process simulation using a one-dimensional model.

P. V. Ananthapadmanabhan; T. K. Thiyagarajan; K. P. Sreekumar; N. Venkatramani

2004-01-01

290

Formulation of anisotropic Hill criteria for the description of an aluminium alloy behaviour during the channel die compression test  

Microsoft Academic Search

During the last years the study of the plastic deformation modes and the anisotropic mechanical behaviour of aluminium alloys have been the subject of many investigations. This paper deals with a phenomenological identification of an anisotropic Hill constitutive equation of aluminium AU4G samples using a channel die compression device at room temperature. By considering the different possible orientations of the

A. Gavrus; H. Francillette

2007-01-01

291

Protective role of lithium during aluminium-induced neurotoxicity.  

PubMed

The present study was designed to examine the protective potential of lithium if any in ameliorating the alterations induced by aluminium (Al) on behavioral and neurochemical indices. Al was given orally (100mg/kg b.wt./day) whereas lithium was administered through diet (1.1g/kg diet) to rats for a total duration of 2 months. Active and passive avoidance tests revealed significant alterations in the short-term memory and cognitive behavior in rats treated with Al. Further, locomotor as well as muscular activities were also found to be significantly affected. Co-administration of lithium with Al caused significant improvement in the short-term memory, cognition, anxiety, locomotion and muscular activity. Further, Al exposure led to a significant decrease in the acetylcholinesterase activity in both the cerebrum and cerebellum. Monoamine oxidase enzyme activity was significantly increased in cerebrum whereas a decrease was observed in cerebellum after Al treatment. Dopamine and serotonin levels were also found to be significantly decreased but the levels of reactive oxygen species were significantly increased in both the regions following Al treatment. Lithium supplementation to Al treated animals caused a significant improvement in the activities of enzymes acetylcholinesterase and monoamine oxidase which were altered by Al. Further, lithium when given along with Al was also able to regulate the levels of dopamine, serotonin and reactive oxygen species in both the regions and the values were found close to the normal controls. Ultrastructural studies revealed alteration in the structure of synapse after Al treatment. Therefore, the study strengthens the hypothesis that lithium can be used as a neuroprotectant during Al induced neurotoxicity. PMID:19895864

Bhalla, Punita; Garg, M L; Dhawan, D K

2010-01-01

292

Dermal exposure to polycyclic aromatic hydrocarbons among primary aluminium workers.  

PubMed

Large amounts of PAH's are released in the electrode production departments of pre-bake cell aluminium reduction plants. Emission sources are mixing, shaping and baking of the anode (paste plant and bake oven) and pot relining operations. A study was performed to quantify the importance of dermal uptake of PAH's among exposed workers. Twenty workers in the anode production departments (paste plant (N = 8) and bake oven (N = 5)) and the pot relining department (N = 7) volunteered for the study. Monitoring was performed over a period of 5 consecutive days using personal air sampling, dermal contamination sampling and biological monitoring. Pyrene concentrations measured in the respirable air samples, ranged up to 320 micrograms/m3. Dermal contamination of pyrene was monitored at three skin sites (wrist, jaw/neck and groin) using exposure pads as pseudo-skin. The skin contamination with pyrene ranged up to 375 ng/cm2. Contamination of the groin skin site, although covered by work clothes ranged up to 106 ng/cm2. The concentration of 1-hydroxypyrene in pre and post-shift urine ranged up to 27 mumol/mol creatinine and showed an increase during the day and a decrease during the night. Pyrene in air and pyrene on the skin were tested for significance of correlation with urinary 1-hydroxypyrene in samples taken at several moments: end-of-shift, pre-shift next morning and weekly increase. The correlation coefficients between dermal contamination and urinary 1-hydroxypyrene were equal or higher than the correlation coefficient between pyrene air concentration and urinary 1-hydroxypyrene. The total skin contamination in exposed workers is estimated to be more than three times higher than the intake via the respiratory tract. The contribution of dermal exposure to the total PAH body burden of exposed workers therefore appears to be significant. PMID:1297067

Vanrooij, J G; Bodelier-Bade, M M; De Looff, A J; Dijkmans, A P; Jongeneelen, F J

1992-01-01

293

Peak exposures in aluminium potrooms: instrument development and field calibration.  

PubMed

Aluminium smelter potrooms are unique in that workplace exposures to hydrogen fluoride (HF), sulfur dioxide (SO2), and particulate matter occur simultaneously for some tasks. The peak exposures to these contaminants are of increasing interest in discovering the etiology of respiratory health effects. While a variety of direct-reading instruments are available for sulfur dioxide and particulate matter, only a few exist for hydrogen fluoride. The sensors in these HF instruments have a cross-sensitivity to sulfur dioxide making it difficult to monitor HF in an environment that also contains SO2. To overcome this problem, we assessed the simultaneous use of two electrochemical instruments: one with a SO2 sensor that does not respond to HF and the second with a hydrogen fluoride sensor that responds to both HF and SO2 in a 1 : 1 ratio, termed 'total acid gas'. The difference in the response between the two instruments should indicate the HF concentration: [HF + SO2] minus SO2 equals HF. The performance characteristics of this sampling train were evaluated in the laboratory through the generation of both HF and SO2 with permeation tubes. The response and recovery times for the SO2 only instrument were acceptable (6 and 15 s, respectively), but the "total acid gas" instrument exhibited both slow response and slow recovery approaching three and six min. The association between the traditional integrated filter sampling method and the direct-reading instrument for SO2 is 0.80 (Spearman's rho). The use of the digital filter strengthens the association between the HF direct-reading instrument and the integrated samples from 0.41 to 0.68. PMID:15536509

Carter, Stephanie R; Seixas, Noah S; Thompson, Mary Lou; Yost, Michael G

2004-11-01

294

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

295

Etude de la complexation des ions aluminium par des molécules organiques: Constantes et stoechiométrie des complexes. Application au traitement de potabilisation des eaux  

Microsoft Academic Search

Aluminium salts are commonly used as reactants for coagulation-flocculation in the treatment of drinking water supplies. Powdered activated carbon (PAC) is also sometimes used to decrease accidental or chronic organic pollution. If organic matter has to be removed, powdered activated carbon and aluminium salts can be used simultaneously. The aluminium salts and natural organic matter such as fulvic acids will

G Cathalifaud; J Ayele; M Mazet

1997-01-01

296

Thermoluminescent response of aluminium oxide thin films subject to gamma irradiation  

NASA Astrophysics Data System (ADS)

The thermoluminescent (TL) properties of amorphous aluminium oxide thin films (thickness of the order of 0.3 ?m) subjected to gamma (Co-60) irradiation are reported. Aluminium oxide thin films were prepared by laser ablation from an Al2O3 target using a Nd:YAG laser with emission at the fundamental line. The films were exposed to gamma radiation (Co-60) in order to study their TL response. Thermoluminescence glow curves exhibited two peaks, one at 110 °C and another at 176 °C. The high temperature peak shows a reasonable stability and ˜30% fading in the first five days after irradiation. A linear relationship between the absorbed dose and the thermoluminescent response for doses from 150 mGy to 100 Gy was observed. These results suggest that aluminium oxide thin films are suitable for detection and monitoring of gamma radiation.

Arrieta, A.; Escobar-Alarcón, L.; Camps, E.; Gonz&Ález, P. R.

297

Evaluation Of Four Welding Arc Processes Applied To 6061 Aluminium Alloy  

SciTech Connect

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. [Univ Paris-Sud, Laboratoire de Physico-Chimie de l'Etat Solide, UMR 8182, 91405 Orsay, F-91405 (France); Laboratoire de Genie des Materiaux et Procedes Associes (LGMPA), Ecole Polytechnique de l'Universite de Nantes, Nantes Atlantique Universites, rue Christian Pauc, BP 50609, 44306 Nantes Cedex 3 (France); Paillard, P. [Laboratoire de Genie des Materiaux et Procedes Associes (LGMPA), Ecole Polytechnique de l'Universite de Nantes, Nantes Atlantique Universites, rue Christian Pauc, BP 50609, 44306 Nantes Cedex 3 (France); Baudin, T. [Univ Paris-Sud, Laboratoire de Physico-Chimie de l'Etat Solide, UMR 8182, 91405 Orsay, F-91405 (France); CNRS, Orsay, F-91405 (France); Jobez, S.; Castagne, J.-F. [SNECMA-Usine d'Evry-Corbeil Snecma Evry-Corbeil-Route Henri Auguste Desbrueres-91000 Evry (France)

2011-01-17

298

Towards the structure of rare earth luminescence centres - terbium doped aluminium nitride as an example system  

NASA Astrophysics Data System (ADS)

Sputter deposited terbium doped aluminium nitride layers were investigated with respect to the distribution and surroundings of the terbium luminescence ions. Semi-empirical calculations indicate that terbium forms complexes consisting of one aluminium vacancy surrounded by three oxygen ions on nitrogen lattice positions and one nitrogen ion that is bound to a terbium ion on a distorted aluminium lattice position. The crystal field splitting of the terbium ions indicate their surroundings to be not tetrahedral but, as anticipated from the determined complex, C3v. Complementary electron microscopic investigations show a random distribution of these complexes within the layer volume. The terbium ions cause a shape of the Tb M5,4 edge similar to the shapes in other ionic compounds like Tb2O3.

Benz, Felix; Walther, Thomas; Strunk, Horst P.

2013-11-01

299

Aluminium phosphide (tank pill) poisoning in the Transkei region of South Africa: a case report.  

PubMed

About half a million people die each year as a result of various kinds of poisoning. The incidence of pesticide poisoning, which is high in developing countries, has doubled over the past 10 years. Aluminium phosphide is a deadly fumigant pesticide. A 21-year-old man committed suicide by ingesting aluminium phosphide, which he had available in his home. He had been charged with rape, and was to appear in court. Soon after ingestion, he told his grandmother about the suicide attempt. He was taken to a nearby hospital, where he was dead within an hour of arriving. The mechanism of action, symptoms and signs will be discussed in this report. The purpose of this case report is to highlight the problem of aluminium phosphide poisoning in the Transkei region of South Africa. PMID:21793477

Meel, B L

2011-04-01

300

In situ nanoindentation study on plasticity and work hardening in aluminium with incoherent twin boundaries.  

PubMed

Nanotwinned metals have been the focus of intense research recently, as twin boundaries may greatly enhance mechanical strength, while maintaining good ductility, electrical conductivity and thermal stability. Most prior studies have focused on low stacking-fault energy nanotwinned metals with coherent twin boundaries. In contrast, the plasticity of twinned high stacking-fault energy metals, such as aluminium with incoherent twin boundaries, has not been investigated. Here we report high work hardening capacity and plasticity in highly twinned aluminium containing abundant ?3{112} incoherent twin boundaries based on in situ nanoindentation studies in a transmission electron microscope and corresponding molecular dynamics simulations. The simulations also reveal drastic differences in deformation mechanisms between nanotwinned copper and twinned aluminium ascribed to stacking-fault energy controlled dislocation-incoherent twin boundary interactions. This study provides new insight into incoherent twin boundary-dominated plasticity in high stacking-fault energy twinned metals. PMID:25204688

Bufford, D; Liu, Y; Wang, J; Wang, H; Zhang, X

2014-01-01

301

Effect of aluminium metal on glutathione (GSH) level in plasma and cytosolic fraction of human blood.  

PubMed

Aluminium is being used in the medicines in the form of antacids. The Aluminium metal can be leached from our utensils and can harm the body for its side effects, if become available to the systemic circulation. So it is important to check the effect of Aluminum on the Glutathione in vivo condition. Ellman method was used to determine the effect of Aluminum on GSH level in whole blood spectrophotometerically. 5,5-Dithiobis, 2-Nitrobenzoic Acid, Glutathione, Aluminium sulphate, phosphate buffer, HCl (Hydrochloric acid) and other laboratory instruments were used to conduct the research work. Time dependent effect of Aluminum on Glutathione level in whole blood was also checked and decrease was observed. This study also shows the effect of Aluminum as helping agent for the Glutathione to enhance the antioxidant system of the body or a cause for depletion of reduced Glutathione. PMID:21190912

Khan, Haroon; Khan, M Farid; Jan, Syed Umer; Ullah, Naseem

2011-01-01

302

Aluminium-induced electrophysiological, biochemical and cognitive modifications in the hippocampus of aging rats.  

PubMed

Aluminium (Al) is the most abundant metal known for its neurotoxicity in humans. It gains easy access to the central nervous system under normal physiological conditions and accumulates in different brain regions. It has been reported to be involved in the etiology of several neurodegenerative diseases. In this study, we have investigated the effects of long-term intake of aluminium chloride (AlCl(3)) on the electrophysiological, behavioral, biochemical and histochemical functions of hippocampus. Wistar rats were fed with AlCl(3) at a dose of 50mg/(kgday) for 6 months in the drinking water. Effect of long-term intake of Al was studied on the electrical activity of hippocampal CA1 and CA3 regions in brain of young and old rats. Morris water maze and open field tests were performed to investigate the cognitive and anxiety status of aging rats intoxicated with aluminium. Our studies indicate that aluminium intake results in increased multiple unit activity and adversely affect the spatial learning and memory abilities of both young and old rats. Aluminium intake also inflicts oxidative stress-related damage to lipids, membrane associated proteins (Na-K ATPase and PKC) and endogenous antioxidant enzyme activity (SOD, GPx and GST). The compromised antioxidant system might be playing a crucial role in the observed Al-induced alterations. We have observed that the magnitude of AlCl(3)-induced alteration was considerably higher in younger group of rats compared to older group. In conclusion, the results of the present study implicates that aluminium treatment exerts its neurotoxic effects by altering the overall physiology of brain, and the induced changes were strongly correlated with each other. PMID:18817812

Sethi, Pallavi; Jyoti, Amar; Singh, Rameshwar; Hussain, Ejaz; Sharma, Deepak

2008-11-01

303

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

304

Zinc modulates aluminium-induced oxidative stress and cellular injury in rat brain.  

PubMed

Dysregulation of metal homeostasis has been perceived as one of the key factors in the progression of neurodegeneration. Aluminium (Al) has been considered as a major risk factor, which is linked to several neurodegenerative diseases, especially Alzheimer's disease, whereas zinc (Zn) has been reported as a vital dietary element, which regulates a number of physiological processes in central nervous system. The present study was conducted to explore the protective potential of zinc, if any, in ameliorating neurotoxicity induced by aluminium. Male Sprague Dawley rats received either aluminium chloride (AlCl3) orally (100 mg kg(-1) b.wt. per day), zinc sulphate (ZnSO4) at a dose level of 227 mg L(-1) in drinking water or combined treatment of aluminium and zinc for 8 weeks. Aluminium treatment significantly elevated the levels of lipid peroxidation and reactive oxygen species as well as the activities of catalase, superoxide dismutase and glutathione reductase, which however were decreased following Zn co-treatment of Al-treated rats. In contrast, Al treatment decreased the activities of glutathione-S-transferase as well as the levels of reduced glutathione, oxidised glutathione and total glutathione, but co-administration of Zn to Al-treated animals increased these levels. Furthermore, Al treatment caused a significant increase in the levels of Fe and Mn as well as of Al but decreased the Zn and metallothionein levels. In the Zn-supplemented animals, the levels of Al, Fe, Mn were found to be significantly decreased, whereas the levels of metallothionein as well as Zn were increased. Moreover, histopathological alterations such as vacuolization and loss of Purkinje cells were also evident following Al treatment, which showed improvement upon Zn supplementation. Therefore, zinc has the potential to alleviate aluminium-induced neurodegeneration. PMID:25141099

Singla, Neha; Dhawan, D K

2014-10-01

305

Protective role of Cynodon dactylon in ameliorating the aluminium-induced neurotoxicity in rat brain regions.  

PubMed

Cynodon dactylon (Poaceae) is a creeping grass used as a traditional ayurvedic medicine in India. Aluminium-induced neurotoxicity is well known and different salts of aluminium have been reported to accelerate damage to biomolecules like lipids, proteins and nucleic acids. The objective of the present study was to investigate whether the aqueous extract of C. dactylon (AECD) could potentially prevent aluminium-induced neurotoxicity in the cerebral cortex, hippocampus and cerebellum of the rat brain. Male albino rats were administered with AlCl(3) at a dose of 4.2 mg/kg/day i.p. for 4 weeks. Experimental rats were given C. dactylon extract in two different doses of 300 mg and 750 mg/keg/day orally 1 h prior to the AlCl(3) administration for 4 weeks. At the end of the experiments, antioxidant status and activities of ATPases in cerebral cortex, hippocampus and cerebellum of rat brain were measured. Aluminium administration significantly decreased the level of GSH and the activities of SOD, GPx, GST, Na(+)/K(+) ATPase, and Mg(2+) ATPase and increased the level of lipid peroxidation (LPO) in all the brain regions when compared with control rats. Pre-treatment with AECD at a dose of 750 mg/kg b.w increased the antioxidant status and activities of membrane-bound enzymes (Na(+)/K(+) ATPase and Mg(2+) ATPase) and also decreased the level of LPO significantly, when compared with aluminium-induced rats. The results of this study indicated that AECD has potential to protect the various brain regions from aluminium-induced neurotoxicity. PMID:21448563

Sumathi, Thangarajan; Shobana, Chandrasekar; Kumari, Balasubramanian Rathina; Nandhini, Devarajulu Nisha

2011-12-01

306

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

307

Hemi(piperazinediium) hexaaquaaluminium(III) bis(sulfate) tetrahydrate: a new double aluminium sulfate salt.  

PubMed

Piperazinium aluminium sulfate decahydrate, (C(4)H(12)N(2))(0.5)[Al(H(2)O)(6)](SO(4))(2).4H(2)O, exhibits a crystal structure built from isolated [Al(H(2)O)(6)](3+), SO(4)(2-), C(4)H(12)N(2)(2+) and H(2)O units connected by a complex hydrogen-bond network. The title compound shows strong similarities to many double aluminium sulfates, such as alums and Tutton's salts. However, since its structure is not derived directly from that of these compounds, it is assumed to be a new structure type. PMID:14605390

Bataille, Thierry

2003-11-01

308

Band gap and conductivity variations of ZnO thin films by doping with Aluminium  

NASA Astrophysics Data System (ADS)

Zinc Oxide thin films were prepared by Successive Ionic layer adsorption and reaction technique(SILAR). Aluminium was doped for different doping concentrations from 3 at.% to 12 at.% in steps of 3 at.%. Conductivity of the samples were taken at different temperatures. UV Spectrograph of the samples were taken and the band gap of each sample was found from the data. It was observed that as the doping concentration of Aluminium increases, the band gap of the samples decreases and concequently conductivity of the samples increases.

Vattappalam, Sunil C.; Thomas, Deepu; T, Raju Mathew; Augustine, Simon; Mathew, Sunny

2015-02-01

309

Severe reversible myocardial injury associated with aluminium phosphide toxicity: A case report and review of literature  

PubMed Central

Aluminium phosphide is commonly used as an insecticide and can be toxic to humans at the cellular level by interfering with mitochondrial energy metabolism. We report on three cases of severe aluminium phosphide cardio-toxicity, resulting in severe decrease in both ventricular heart functions. The first case succumbed to intractable ventricular arrhythmias complicated by multi-organ failure before she died; while the other two cases required invasive hemodynamic support and eventually improved over the course of 10–14 days. We describe our experience and the challenges faced while managing one of them. PMID:25278724

Elabbassi, Wael; Chowdhury, Mohammed Andaleeb; Fachtartz, Arif Al Nooryani

2013-01-01

310

Severe reversible myocardial injury associated with aluminium phosphide toxicity: A case report and review of literature.  

PubMed

Aluminium phosphide is commonly used as an insecticide and can be toxic to humans at the cellular level by interfering with mitochondrial energy metabolism. We report on three cases of severe aluminium phosphide cardio-toxicity, resulting in severe decrease in both ventricular heart functions. The first case succumbed to intractable ventricular arrhythmias complicated by multi-organ failure before she died; while the other two cases required invasive hemodynamic support and eventually improved over the course of 10-14 days. We describe our experience and the challenges faced while managing one of them. PMID:25278724

Elabbassi, Wael; Chowdhury, Mohammed Andaleeb; Fachtartz, Arif Al Nooryani

2014-10-01

311

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

NASA Astrophysics Data System (ADS)

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, ? = 0.66 ?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 EL = 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-?m thick base aluminium layer was equal to 35+/-1.6 km s-1, and in simulations to 36 km s-1. In the experiment with four laser beams (for EL = 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-1, and in simulations to 30 km s-1.

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

2013-07-01

312

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

313

Addition and Subtraction  

NSDL National Science Digital Library

Welcome students, Using this website, you can play fun and interactive games and print out fun worksheets that will help you practice addition and subtraction. Please explore the website and print out as many worksheets as you would like. Print out and answer the problems on this worksheet. Addition and Subtraction Worksheet This game is for more advanced students in addition and subtraction. Figure out what sign to put in between the numbers to make the combination on the right. Advanced Add and Subtract Game This fun animal game will help you practice your addition and subtraction. Farm Animal Game Print ...

Ms. Roberts

2011-04-20

314

Yet another additivity conjecture  

E-print Network

It is known that the additivity conjecture of Holevo capacity, output minimum entoropy, and the entanglement of formation (EoF), are equivalent with each other. Among them, the output minimum entropy is simplest, and hence many researchers are focusing on this quantity. Here, we suggest yet another entanglement measure, whose strong superadditivity and additivity are equivalent to the additivity of the quantities mentioned above. This quantity is as simple as the output minimum entropy, and in existing proofs of additivity conjecture of the output minimum entropy for the specific examples, they are essentially proving the strong superadditivity of this quantity.

Keiji Matsumoto

2005-09-15

315

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

316

Well servicing fluid additive  

Microsoft Academic Search

Disclosed is a fluid, pourable well servicing fluid additive comprising a water-soluble polymer, an alkaline earth metal base, and a fibrous material suspended in an oleaginous liquid with a gellant and, optionally, a dispersant therefor. The additive is useful in preparing spud muds, lost circulation pills, and spacer fluids during well servicing operations.

Moity

1984-01-01

317

Identification of aluminium-regulated genes by cDNA AFLP in rice (Oryza sativa L.): aluminium-regulated genes for the metabolism of cell wall components  

Microsoft Academic Search

Aluminium (Al) toxicity is the major factor limiting crop productivity in acid soils. To investigate the molecular mechanisms of Al toxicity and Al tolerance of rice, cDNA-amplified fragment length polymorph- ism (cDNA-AFLP) was used for identifying Al-regu- lated genes in roots of an Al-tolerant tropical upland rice, Azucena, and an Al-sensitive lowland rice, IR1552. Nineteen function-known genes were found among

Chuanzao Mao; Keke Yi; Ling Yang; Bingsong Zheng; Yunrong Wu; Feiyan Liu; Ping Wu

2004-01-01

318

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

319

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

320

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 ...

Ms. Smith

2010-10-14

321

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.

Utah State University

2011-06-28

322

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.

323

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

324

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

325

Additions to LAP  

E-print Network

In addition to the description on page 13 of AI Memo 116A LAP has the following features: Current Assembly Location Reference, Assembly Time Arithmetic, Constants, Multiple Entry Routines, and Defined Machine Operations ...

White, John L.

1967-07-01

326

Preparation of glass-ceramics from red mud in the aluminium industries  

Microsoft Academic Search

The feasibility of recycling red mud and fly ash in the aluminium industries by producing glasses and glass-ceramics has been investigated. The crystallization behavior of glass-ceramics mostly produced from red mud and fly ash was studied by DTA, XRD, optical microscopy techniques. According to DTA curve, nucleation experiments were carried out at various nucleation temperatures at the same crystallization temperature

Jiakuan Yang; Dudu Zhang; Jian Hou; Baoping He; Bo Xiao

2008-01-01

327

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

Microsoft Academic Search

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

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

2006-01-01

328

Mechanical response of 2024-7075 aluminium alloys joined by Friction Stir Welding  

Microsoft Academic Search

The mechanical and microstructural properties of 2024 and 7075 aluminium alloys joined together by friction stir welding were analysed in the present study. The two materials were welded with perpendicular rolling direction and after were tested in tension at room temperature in order to analyse the mechanical response and to observe the differences with the parent materials, the tensile response

P. Cavaliere; E. Cerri; A. Squillace

2005-01-01

329

Effet d'un renforcement d'aluminium sur la fragmentation dynamique du SiC  

E-print Network

of a hard material and a backing made of a ductile material. These solutions are among the most interesting in terms of mass efficiency. A new material made of porous silicon carbide infiltrated with aluminium is considered. The presence of an aluminum skeleton may improve the residual strength after impact. The present

330

Image analysis of atmospheric corrosion of field exposure high strength aluminium alloys  

Microsoft Academic Search

The corrosion morphology image acquisition system which can be used in the field was established. In Beijing atmospheric corrosion exposure station, the image acquisition system was used to capture the early stage corrosion morphology of five types of high strength aluminium alloy specimens. After the denoise treatment, wavelet-based image analysis method was applied to decompose the improved images and energies

Lei Tao; Shizhe Song; Xiaoyun Zhang; Zheng Zhang; Feng Lu

2008-01-01

331

Numerical modelling of an innovative induction heating technique for aluminium extrusion process  

Microsoft Academic Search

The paper describes numerical models developed to simulate induction heating process for aluminium billet heating by rotation in a DC magnetic field. 2D and 3D numerical approach to coupled electromagnetic and thermal process modelling and the results of investigation are presented. Influence of rotation speed on temperature distribution in cross-section of the billet is investigated. Influence of electromagnetic effects on

M. Zlobina; B. Nacke; A. Nikanorov; S. Galunin

2008-01-01

332

ON THE INFLUENCE OF HUMAN FACTOR ON MECHANICAL PROPERTIES IN ALUMINIUM HOT EXTRUSION PROCESS  

Microsoft Academic Search

A non-parametric model was proposed for modelling the influence of different technological and chemical pa- rameters on the mechanical properties of the 6082 aluminium alloys during the hot extrusion process with a special consideration of human factor. It was shown that human factor (influence of process engineers) was important and that it could be efficiently modelled and taken into account

I. PERU; M. FAZARINC; G. KUGLER; P. FAJFAR

333

Validation of the simplified super folding element theory applied for axial crushing of complex aluminium extrusions  

Microsoft Academic Search

The Simplified Super Folding Element theory (SSFE) has been applied to predict the mean axial crush force of a wide range of aluminium extrusions with rather complex cross sections. The results from the SSFE theory have been compared with finite element (FE) simulations and experimental tests. It was found that in most cases the SSFE theory was able to predict

A G Hanssen; A Artelius; M Langseth

2007-01-01

334

Effect of primary intermetallic particles on surface microstructure and appearance of aluminium extrusions  

Microsoft Academic Search

Different amounts of coarse intermetallic particles were produced in an aluminium alloy by variations of the iron content. Microstructural examination of the extrusion surface shows that Fe-rich intermetallic particles reduce the grain size, randomize the texture, retard the recrystallization process and decrease the difference in the fraction of high-angle grain boundaries. After alkaline etching, the primary intermetallic particles decrease the

Hanliang Zhu; Xinquan Zhang; Malcolm J. Couper; Arne K. Dahle

2009-01-01

335

Lifetime evaluation of two different hot work tool steels in aluminium extrusion  

Microsoft Academic Search

During aluminium extrusion, the die experience cyclic thermo-mechanical loads that can lead to materials degradation and failure. For a process optimization and a comparison of different hot work tool steels, the finite element method is an appropriate means. Local inelastic strains result from the interaction of the applied temperature and stress loading and can be computed by suitable inelastic constitutive

C. Sommitsch; R. Sievert; T. Wlanis; C. Redl

2008-01-01

336

Static and dynamic axial crushing of square thin-walled aluminium extrusions  

Microsoft Academic Search

An experimental investigation was carried out to study the behaviour of square thin-walled aluminium extrusions in alloy AA6060 subjected to axial loading. Both static and dynamic tests were performed and the primary variables were the wall thickness and temper of the square tubes and the impact velocity of the projectile. The mass of the projectile in the dynamic tests was

M. Langseth; O. S. Hopperstad

1996-01-01

337

An investigation of material properties and geometrical dimensions of aluminium extrusions  

Microsoft Academic Search

The increasing demand for aluminium extrusions calls for relevant statistical data to establish objective measures of uncertainties associated with the material description and cross-sectional geometry. A total of 392 tensile test specimens are machined from 49 rectangular hollow section extrusions in order to investigate how the material properties are distributed. The Kolmogorov–Smirnov hypothesis test indicates that the normal as well

Arild H Clausen; Tore Tryland; Svein Remseth

2001-01-01

338

Modelling of creep-fatigue in containers during aluminium and copper extrusion  

Microsoft Academic Search

During hot extrusion of aluminium alloys, extrusion dies experience cyclic temperature changes as well as multiaxial loadings. To improve the service life of the dies, cleaner and high hot strength materials are designed as well as an optimised process control is performed. For the improvement of the process guiding and a comparison of lifetime behaviour of different hot work tool

C. Sommitsch; R. Sievert; T. Wlanis; B. Günther; V. Wieser

2007-01-01

339

Reliability-based analysis of a stretch-bending process for aluminium extrusions  

Microsoft Academic Search

The paper presents reliability analyses of a plastic forming process. Stretch-bending of extruded aluminium square hollow sections was studied through finite element analysis. The profiles were axially fixed and given a specified curvature by means of a bending die. Important response parameters in stretch-bending of extruded profiles are flange sagging and elastic springback. The sensitivity of the predicted response parameters

O. S. Hopperstad; B. J. Leira; S. Remseth; E. Trømborg

1999-01-01

340

An effective split of flow and die deformation calculations of aluminium extrusion  

Microsoft Academic Search

The purpose of the research project of which this paper is a result is to gain insight in design and control parameters of aluminium extrusion by FE simulations. This is done by means of a thermal FE code based on an ALE algorithm (Dieka). A short overview is given of the material models as well as the FE methods that

H. G. Mooi; P. T. G. Koenis; J. Huétink

1999-01-01

341

Wear of surface treated dies for aluminium extrusion — a case study  

Microsoft Academic Search

Dies for extrusion of aluminium alloys are exposed to severe thermal, chemical and mechanical conditions. Extrusion dies are usually made from hot work tool steels such as AISI H13. In order to reduce wear they are almost always surface treated by various forms of nitriding. Surface-coating by physical vapour deposition (PVD) or chemical vapour deposition (CVD) is currently being introduced

Thomas Björk; Richard Westergård; Sture Hogmark

2001-01-01

342

METHOD FOR POCKET DIE DESIGN ON THE BASIS OF NUMERICAL INVESTIGATIONS OF ALUMINIUM EXTRUSION PROCESS  

Microsoft Academic Search

The paper considers dependences of metal forming characteristics on dimensionless geometrical parameters of flat pocket die design at direct extrusion of aluminium thin-walled solid profiles. The theoretical analysis of plastic metal flow is carried out by means of the 2-D FEM model. The new method for flat pocket die design is proposed in the paper. The die design example is

O. Golovko; O. Grydin

2006-01-01

343

Three-dimensional simulation of aluminium extrusion by the ?-shape based natural element method  

Microsoft Academic Search

In this work we study the possible advantages of an updated Lagrangian perspective in the numerical simulation of aluminium extrusion. For this purpose, we have employed a well established meshless technique known as Natural Element Method (NEM). This technique presents some advantages over finite element simulations, such as no remeshing requirements and the accuracy of the approximation even with highly

I. Alfaro; D. Bel; E. Cueto; M. Doblare; F. Chinesta

2006-01-01

344

Finite element modelling simulation of transverse welding phenomenon in aluminium extrusion process  

Microsoft Academic Search

Transverse welds occur in the billet-to-billet extrusion process, which is often used in modern aluminium extrusion plants for the purpose of continuous production. The transverse weld introduces a discontinuity at the weld interface in the extruded product and in many structural applications. This is not acceptable because it can severely reduce the strength and is detrimental to the quality of

Qiang Li; Chris Harris; Mark R. Jolly

2003-01-01

345

Individual influence of forming parameters on surface recrystallization during aluminium extrusion  

Microsoft Academic Search

It is well-known that during extrusion of aluminium alloys, the operating parameters (extrusion ratio, ram speed, billet temperature and extrusion mode) influence subsequent surface recrystallization. Research has been made on the influence of some parameters but the individual influence of each parameter is not clear. In this study, the respective influence of the major parameters is studied using the Taguchi

Z. Peng; T. Sheppard

2004-01-01

346

Transition from progressive to global buckling of aluminium extrusions – a numerical study  

Microsoft Academic Search

Numerical simulations using LS-DYNA were carried out in order to study the transition between progressive and global buckling of axially loaded aluminium extrusions in alloy AA6060 temper T6. A numerical model was validated against experimental tests and good agreement was found between the progressive buckling pattern in the numerical simulations and experimental tests. The numerical simulations were capable of giving

Ø Jensen; O. S. Hopperstad; M. Langseth

2005-01-01

347

Temperature measurement of aluminium on an extrusion press using the new BACO radiation pyrometer  

Microsoft Academic Search

A new sensitive lead sulphide cell pyrometer has been developed which enables the temperatures of aluminium extrusions to be continuously monitored or controlled during processing to about ± 10 degC. The narrow field of view (¾ in width at 7 ft viewing distance) enables the pyrometer to be mounted on the guillotine of the press to view the extrusion down

D. D. Beattie

1968-01-01

348

Plasma electrolytic fabrication of oxide ceramic surface layers for tribotechnical purposes on aluminium alloys  

Microsoft Academic Search

The problem of technical and economical optimization of the process of micro-arc discharge oxidation of high-strength aluminium for the fabrication of oxide ceramic layers for tribotechnical purposes is considered in terms of experimental design. To estimate the effectiveness of the process, a generalized parameter is used which accounts for oxide mass yield as a principal parameter, and mechanical and geometrical

A. L. Yerokhin; A. A. Voevodin; V. V. Lyubimov; J. Zabinski; M. Donley

1998-01-01

349

Dynamic fracture toughness of aluminium 6063 with multilayer composite patching at lower temperatures  

Microsoft Academic Search

Aluminium alloys provide many benefits and challenges for use in marine environment. Attention on lightweight hulls leads to power saving, better handling and easy transportation. The stiffness and mass of the structure or member is responsible for its natural vibration. The hull panels and stiffeners vibrate at different frequencies when their stiffness is reduced by formation of a crack or

G. L. Manjunath; S. Surendran

2012-01-01

350

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

E-print Network

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

Boyer, Edmond

351

SHALLOW WATER MODEL FOR ALUMINIUM ELECTROLYSIS CELLS WITH VARIABLE TOP AND BOTTOM  

Microsoft Academic Search

The MHD wave instability in commercial cells for electrolytic aluminium production is often described using 'shallow water' models. The model (1) is extended for a variable height cathode bottom and anode top to account for realistic cell features. The variable depth of the two fluid layers affects the horizontal current density, the wave development and the stability threshold. Instructive examples

Valdis Bojarevics; Koulis Pericleous

2008-01-01

352

Modelling the environmental impact of an aluminium pressure die casting plant and options for control  

Microsoft Academic Search

This study describes a model (MIKADO) to analyse options to reduce the environmental impact of aluminium die casting. This model will take a company perspective, so that it can be used as a decision-support tool for the environmental management of a plant. MIKADO can be used to perform scenario analyses to analyse the impact on the environment of different strategies,

Belmira Neto; Carolien Kroeze; Leen Hordijk; Carlos Costa

2008-01-01

353

Diffusion kinetics in aluminium–gold bond contacts from first-principles density functional calculations  

Microsoft Academic Search

A common joining method in microelectronics is thermosonic bonding of gold wires to aluminium pads deposited on the integrated circuit. In the interface between the wire and the pad a number of intermetallic compounds AlxAuy can develop, which significantly affect the mechanical properties and corrosion resistance of the bonds. Based on Onsager’s extremal principle of irreversible thermodynamics, the present paper

Christian M. Ulrich; Adham Hashibon; Ji??´ Svoboda; Christian Elsässer; Dirk Helm; Hermann Riedel

2011-01-01

354

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

E-print Network

ABSTRCT Fibre Bragg Grating (FBG) array sensors have been successfully embedded in aluminium alloy matrix Bragg Grating, Optical Fibre Sensor, Smart Structure, Ultrasonic Consolidation 1. INTRODUCTION In-fibre 2.1 Fabrication of Fibre Bragg Gratings The FBG array sensors were UV-inscribed in single mode

Neirotti, Juan Pablo

355

Enhancement of thermoelectric figure-of-merit by resonant states of aluminium doping in lead selenide  

E-print Network

By adding aluminium (Al) into lead selenide (PbSe), we successfully prepared n-type PbSe thermoelectric materials with a figure-of-merit (ZT) of 1.3 at 850 K. Such a high ZT is achieved by a combination of high Seebeck ...

Zhang, Qinyong

356

Numerical simulation study of laser-driven shock wave propagation in planar aluminium foils  

Microsoft Academic Search

A comprehensive numerical simulation study of laser-driven shock wave propagation in planar aluminium foils, 20– 50? m, is performed using the one-dimensional radiation hydrodynamic code MULTI. The effect of the spatial mesh size on the shock velocity and peak shock pressure is found to be significant and the optimum mesh size is obtained. Shock velocities and maximum pressure are calculated

V K Senecha; Jie Zhang; Wie Wang; H C Pant

2002-01-01

357

Process Simulation of Aluminium Sheet Metal Deep Drawing at Elevated Temperatures  

NASA Astrophysics Data System (ADS)

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

Winklhofer, Johannes; Trattnig, Gernot; Lind, Christoph; Sommitsch, Christof; Feuerhuber, Hannes

2010-06-01

358

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

NASA Astrophysics Data System (ADS)

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

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

2015-04-01

359

Observation of surface plasmons by transition radiation from smooth aluminium films  

E-print Network

, in suitable configuration. It is known that charged particles can excite surface plasmons, but in general media. Non radiative surface plasmons excited by electrons on rough surfaces can however radiate lightL-167 Observation of surface plasmons by transition radiation from smooth aluminium films A

Boyer, Edmond

360

Application of wear-resistant PACVD coatings in aluminium diecasting: economical and ecological aspects  

Microsoft Academic Search

One of the major manufacturing techniques for aluminium precision parts is the pressure diecasting process. However, nowadays the state of the art involves the application of large amounts of lubricants. Their side effects include a decrease in the surface quality of the cast as well as ecological risks. The deposition of wear-resistant coatings provides a means of minimising the use

C. Pfohl; A. Gebauer-Teichmann; K.-T. Rie

1999-01-01

361

Characterization of integrated circuit aluminium bonding pads by nanoindentation and scanning force microscopy  

Microsoft Academic Search

The mechanical properties of thin films and surface modified layers can be measured by a variety of different techniques, with nanoindentation being one of the most recent developments in this growing field. It is particularly suited to the characterization of bonding pads used to connect individual microcircuits and chips. Such pads are commonly made of aluminium and have a thickness

N. X. Randall; Egon Holländer; C. Julia-Schmutz

1998-01-01

362

Scatter bands summarizing the fatigue strength of aluminium alloy bolted joints  

Microsoft Academic Search

A large number of geometrical, technological and environmental factors theoretically influence the fatigue behaviour and the failure modes of the bolted joints. In order to make clear the influence of some of such variables, in this work over one hundred aluminium symmetric double butt joints were tested, subdivided into eight series, with the purpose to compare their fatigue properties and

P. Lazzarin; V. Milani; M. Quaresimin

1997-01-01

363

Pretreatments and filiform corrosion resistance of cataphoretic painted aluminium characterization by EIS and spectroscopic ellipsometry  

Microsoft Academic Search

Aluminium alloys are widely used in architectural, aeronautic and car industries. They are usually protected by the formation of a thick oxide layer (anodization) or by applying an organic coating. In the latter case, a particular type of corrosion called filiform corrosion can occur. This corrosion is characterized by a paint adhesion loss and the occurrence of threads at the

V. Poulain; J.-P. Petitjean; E. Dumont; B. Dugnoille

1996-01-01

364

Singapore Welding Society Newsletter, September 1999 Problems in Welding of High Strength Aluminium Alloys  

E-print Network

) Hydrogen within the filler metal and parent metal; (2) Hydrogen-containing contamination (e.g., oil is hydrogen contamination. Solubility of hydrogen in superheated liquid aluminium is very high) Moisture in the shielding gas. #12;3 The greatest single source of porosity is the surface contamination

Zhou, Wei

365

Inhibition effects of some plant extracts on the acid corrosion of aluminium alloy  

Microsoft Academic Search

Corrosion inhibition of aluminium alloy (AA3003) in 0.5 M HCl by extracts of selected plants was investigated using gravimetric technique at 30 and 60°C. The studied plant materials include extracts of Euphorbia hirta and Dialum guineense. The results indicate that all the extracts inhibited the corrosion process in the medium by virtue of adsorption and inhibition efficiency improved with concentration.

L. A. Nnanna; B. N. Onwuagba; I. M. Mejeha; K. B. Okeoma

2010-01-01

366

Piezoelectric Behaviour of Sputtered Aluminium Nitride Thin Film for High Frequency Ultrasonic Sensors  

NASA Astrophysics Data System (ADS)

Many new materials and processes require non destructive evaluation in higher resolutions by phased array ultrasonic techniques in a frequency range up to 250 MHz. This paper presents aluminium nitride, a promising material for the use as a piezoelectric sensor material in the considered frequency range, which contains the potential for high frequency phased array application in the future. This work represents the fundamental development of piezoelectric aluminium nitride films with a thickness of up to 10 ?m. We have investigated and optimized the deposition process of the aluminium nitride thin film layers regarding their piezoelectric behavior. Therefore a specific test setup and a measuring station were created to determine the piezoelectric charge constant (d33) and the electro acoustic behavior of the sensor. Single element transducers were deposited on silicon substrates with aluminium electrodes for top and bottom, using different parameters for the magnetron sputter process, like pressure and bias voltage. Afterwards acoustical measurements up to 500 MHz in pulse echo mode have been carried out and the electrical and electromechanical properties were qualified. In two different parameter sets for the sputtering process excellent piezoelectric charge constant of about 8.0 pC/N maximum were obtained.

Herzog, T.; Walter, S.; Bartzsch, H.; Gittner, M.; Gloess, D.; Heuer, H.

2011-06-01

367

Aluminium and strontium in calcium supplements and antacids: a concern to haemodialysis patients?  

Microsoft Academic Search

Trace elements, most notably aluminium and strontium, have been noted for their role in the development of secondary bone disorders in haemodialysis patients. Due to the large dosages of calcium required for the maintenance of dialysis patients, this study investigated whether the source of calcium chosen for supplementation, including the form of administration (i.e. chewable forms or capsules), has an

Eric Da Silva; R. Jakubovic; A. Pejovi?-Mili?; D. V. Heyd

2010-01-01

368

Interaction of aluminium with hydrogen in twinning-induced plasticity steel  

E-print Network

in reducing the shear modulus of the austenite contributes to embrittlement via the HELP mechanism; the presence of aluminium re- duces the effect of hydrogen on the modulus and hence on the degree Simulation Pack- age [14­16] within the generalised gradient approximation of the Perdew- Burke

Cambridge, University of

369

The thermal conductivity of plasma electrolytic oxide coatings on aluminium and magnesium  

Microsoft Academic Search

Plasma electrolytic oxide coatings have been produced on both aluminium and magnesium substrates. Their microstructures have been studied and deductions made about formation conditions. The thermal conductivities of the coatings have been measured using a simple steady state method. The values obtained are relatively low (?1 W m?1 K?1). This is explained in terms of the microstructure, which exhibits an

J. A. Curran; T. W. Clyne

2005-01-01

370

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

Microsoft Academic Search

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

Simranpreet Singh Gill; Munish Kaplas

2009-01-01

371

Effect of aluminium on membrane properties of soybean ( Glycine max ) cells in suspension culture  

Microsoft Academic Search

Short-term responses of soybean (Glycine max) cells to aluminium (Al) were studied in suspension culture. Formation of callose was the most sensitive indicator of Al effects. As low as 5 µM Al induced callose formation and an increase in callose concentration could be measured as early as 15 min after beginning the Al treatment. Also membrane permeability was rapidly affected

A. Staß; W. J. Horst

1995-01-01

372

High cycle fatigue damage mechanisms in cast aluminium subject to complex loads  

E-print Network

High cycle fatigue damage mechanisms in cast aluminium subject to complex loads Imade Koutiria to the high cycle fatigue behaviour of cast hypo-eutectic Al­Si alloys. In particular, the AlSi7Cu05Mg03 alloy is investigated. It presents the results of a vast experimental campaign undertaken to investigate the fatigue

Paris-Sud XI, Université de

373

Defluoridation of septentrional Sahara water of north Africa by electrocoagulation process using bipolar aluminium electrodes  

Microsoft Academic Search

The purpose of this paper is to suggest an efficient defluorination process which does not require a big investment. For this, the electrocoagulation process with aluminium bipolar electrodes was used. In the first step, the influence of parameters such as inter-electrode distance, fluoride concentration, temperature and the pH of the solution, were investigated and optimized with synthetic water in batch

N. Mameri; A. R. Yeddou; H. Lounici; D. Belhocine; H. Grib; B. Bariou

1998-01-01

374

Effect of aluminium doping on zinc oxide thin films grown by spray pyrolysis  

Microsoft Academic Search

We report the structural, optical, and electrical characterization of aluminium-doped zinc oxide thin films grown by the spray pyrolysis method. We report the effect of Al concentration on the resistivity and on the X-ray diffraction, transmittance, photoluminescence and Raman scattering spectra of the films. The minimum resistivity is obtained for the sample with nominal Al concentration of 1%. An increase

A. El Manouni; F. J. Manjón; M. Mollar; B. Marí; R. Gómez; M. C. López; J. R. Ramos-Barrado

2006-01-01

375

The alkaline aluminium hydrogen peroxide semi-fuel cell for the HUGIN 3000 autonomous underwater vehicle  

Microsoft Academic Search

This semi-fuel cell uses a circulating alkaline electrolyte, aluminium (Al) anodes and maintain the oxidant concentration in the electrolyte by continuously adding hydrogen peroxide (HP) to the electrolyte. This concept resulted in a safe battery that works at ambient pressure (balanced) and with sufficient power and energy density to allow the AUV HUGIN 3000 underwater surveys of up to 50

O. Hasvold; Kjell Håvard Johansen

2002-01-01

376

Investigation of the formability limit of aluminium tubes drawn with variable wall thickness  

Microsoft Academic Search

Structural aluminium tubes have very important industrial applications, particularly in automobile industry. Tube drawing process is widely used to reduce the outer and inner diameters of tubes. An important issue in the tube drawing process to obtain variable wall thickness is how to determinate and predict its formability limits. Previously published works generally deal with the formability limit of conventional

Q. H. Bui; R. Bihamta; M. Guillot; G. D’Amours; A. Rahem; M. Fafard

2011-01-01

377

6111 Aluminium alloy strip casting using an unequal diameter twin roll caster  

Microsoft Academic Search

An unequal diameter twin roll caster with a long solidification length was devised to cast aluminium alloy strip with a thickness of about 5mm at speed higher than 20m\\/min. The characteristics of the unequal diameter twin roll caster with a long solidification length are as follows. The diameter of the lower roll is four times larger than that of the

Toshio Haga; Masaaki Ikawa; Hisaki Wtari; Shinji Kumai

2006-01-01

378

Aluminium substitution in iron(II III)-layered double hydroxides: Formation and cationic order  

NASA Astrophysics Data System (ADS)

The formation and the modifications of the structural properties of an aluminium-substituted iron(II-III)-layered double hydroxide (LDH) of formula Fe4IIFe(2-6y)IIIAl6yIII (OH) 12 SO 4, 8H 2O are followed by pH titration curves, Mössbauer spectroscopy and high-resolution X-ray powder diffraction using synchrotron radiation. Rietveld refinements allow to build a structural model for hydroxysulphate green rust, GR(SO 42-), i.e. y=0, in which a bilayer of sulphate anions points to the Fe 3+ species. A cationic order is proposed to occur in both GR(SO 42-) and aluminium-substituted hydroxysulphate green rust when y<0.08. Variation of the cell parameters and a sharp decrease in average crystal size and anisotropy are detected for an aluminium content as low as y=0.01. The formation of Al-GR(SO 42-) is preceded by the successive precipitation of Fe III and Al III (oxy)hydroxides. Adsorption of more soluble Al III species onto the initially formed ferric oxyhydroxide may be responsible for this slowdown of crystal growth. Therefore, the insertion of low aluminium amount ( y˜0.01) could be an interesting way for increasing the surface reactivity of iron(II-III) LDH that maintains constant the quantity of the reactive Fe II species of the material.

Ruby, Christian; Abdelmoula, Mustapha; Aissa, Rabha; Medjahdi, Ghouti; Brunelli, Michela; François, Michel

2008-09-01

379

A systematic investigation of aluminium ion speciation at high temperature. Part 1. Solution studies.  

PubMed

Speciation diagrams of aluminium ions in aqueous solution (0.2 M) at high temperature (90 degrees C) have been obtained from 48 h time-resolved multi-batch titration experiments monitored by 27Al NMR spectroscopy, potentiometry and dynamic light scattering. The quantitative speciation patterns and kinetic data obtained offer a dynamic picture of the distribution of soluble and insoluble Al species as a function of hydrolysis ratio h(h=[OH-]/[Al3+]) over a very broad range of conditions (-1.0 < or =h < or = 4.0). Monomeric, small oligomeric, tridecameric (the 'Al13-mer') and the recently characterised 30-meric aluminium species (the 'Al30-mer') as well as aluminium hydroxide have been identified and quantified. The Al13-mer species dominates over a relatively broad range of hydrolysis ratios (1.5 < or =h< or = 2.7) during the first 6 h of experiment, but are gradually replaced by Al30-mers at longer reaction times. Kinetic profiles indicate that the formation of the Al30-mer is limited by the disappearance of the Al13 species at mildly acidic conditions. The estimated rate constants of both hydrolytic processes show good internal correlation at h> or = 1.5. The effect of local perturbations leading to the formation of aluminium hydroxide below the electroneutrality point (h= 3.0) has been estimated quantitatively. PMID:15957049

Shafran, Kirill L; Perry, Carole C

2005-06-21

380

Machining of 6061 aluminium alloy with MQL, dry and flooded lubricant conditions  

Microsoft Academic Search

This paper reports on the effect of different lubricant environments when 6061 aluminium alloy is machined with diamond-coated carbide tools. The effect of dry machining, minimum quantity of lubricant (MQL), and flooded coolant conditions was analyzed with respect to the cutting forces, surface roughness of the machined work-piece and tool wear. The three types of coolant environments are compared. It

P. S. Sreejith

2008-01-01

381

Experimental synovitis induced by aluminium phosphate in rabbits. Comparison of the changes produced in synovial tissue and in articular cartilage by aluminium phosphate, carrageenin, calcium hydrogen phosphate dihydrate, and natural diamond powder.  

PubMed

The goal of this experimental study was to examine the effect on articular tissue of tribasic aluminium phosphate (crystalline and amorphous forms) after intraarticular injection in rabbit and to compare it with that of various phlogistic compounds such as carrageenin, calcium hydrogen phosphate dihydrate and diamond powder, as a control. Synovium and cartilage were studied with light microscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive micro-analysis (EDM). Crystalline and amorphous aluminium phosphate could induce a synovitis with articular effusion in rabbits. With TEM, lysosomal inclusions of phagocytosed material were observed. Through SEM coupled with EDM, aluminium associated with phosphate was found in cellular elements. PMID:6087947

Delongeas, J L; Netter, P; Boz, P; Faure, G; Royer, R J; Gaucher, A

1984-01-01

382

Aluminium induced oxidative stress results in decreased mitochondrial biogenesis via modulation of PGC-1? expression  

SciTech Connect

The present investigation was carried out to elucidate a possible molecular mechanism related to the effects of aluminium-induced oxidative stress on various mitochondrial respiratory complex subunits with special emphasis on the role of Peroxisome proliferator activated receptor gamma co-activator 1? (PGC-1?) and its downstream targets i.e. Nuclear respiratory factor-1(NRF-1), Nuclear respiratory factor-2(NRF-2) and Mitochondrial transcription factor A (Tfam) in mitochondrial biogenesis. Aluminium lactate (10 mg/kg b.wt./day) was administered intragastrically to rats for 12 weeks. After 12 weeks of exposure, we found an increase in ROS levels, mitochondrial DNA oxidation and decrease in citrate synthase activity in the Hippocampus (HC) and Corpus striatum (CS) regions of rat brain. On the other hand, there was a decrease in the mRNA levels of the mitochondrial encoded subunits–NADH dehydrogenase (ND) subunits i.e. ND1, ND2, ND3, Cytochrome b (Cytb), Cytochrome oxidase (COX) subunits i.e. COX1, COX3, ATP synthase (ATPase) subunit 6 along with reduced expression of nuclear encoded subunits COX4, COX5A, COX5B of Electron transport chain (ETC). Besides, a decrease in mitochondrial DNA copy number and mitochondrial content in both regions of rat brain was observed. The PGC-1? was down-regulated in aluminium treated rats along with NRF-1, NRF-2 and Tfam, which act downstream from PGC-1? in aluminium treated rats. Electron microscopy results revealed a significant increase in the mitochondrial swelling, loss of cristae, chromatin condensation and decreases in mitochondrial number in case of aluminium treated rats as compared to control. So, PGC-1? seems to be a potent target for aluminium neurotoxicity, which makes it an almost ideal target to control or limit the damage that has been associated with the defective mitochondrial function seen in neurodegenerative diseases. - Highlights: • Aluminium decreases the mRNA levels of mitochondrial and nuclear encoded subunits. • It decreases the mtDNA copy number and mitochondrial content in rat brain. • It down-regulates the mRNA and protein levels of PGC-1?, NRF-1, NRF-2 and Tfam. • It also disturbs the mitochondrial or nuclear architecture of neurons. • Finally it also decreases mitochondrial number in HC and CS regions of rat brain.

Sharma, Deep Raj; Sunkaria, Aditya; Wani, Willayat Yousuf; Sharma, Reeta Kumari; Kandimalla, Ramesh J.L. [Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh 160012 (India); Bal, Amanjit [Department of Histopathology, Postgraduate Institute of Medical Education and Research, Chandigarh (India); Gill, Kiran Dip, E-mail: kdgill2002@yahoo.co.in [Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh 160012 (India)

2013-12-01

383

Additive Manufacturing Infrared Inspection  

NASA Technical Reports Server (NTRS)

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

Gaddy, Darrell

2014-01-01

384

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

385

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

386

Fuel oil additives  

SciTech Connect

This patent describes a fuel oil composition comprising fuel oil and an additive wherein the additive comprises an AB or ABA block copolymer. It comprises: the A block(s) consist essentially of polymerized monomers selected from the group consisting of acrylate and methacrylate monomers without amine groups wherein the ester is made from an alcohol having 4-60 carbon atoms, and the B block consists essentially of polymerized monomers selected from the group consisting of acrylate and methacrylate monomers containing primary, secondary or tertiary amine groups, with other acrylate and methacrylate monomers, wherein the copolymer contains at least 2 monomer units in each A block and from 2 to 500 amine monomers units in the B block with a concentration in the additive of 10-70% by weight copolymer in solvent, and a concentration of at least 0.5-500 mg/liter of the copolymer in the fuel oil.

Henry, C.P.; West, M.W.J.

1991-04-30

387

What are additives?  

PubMed

Historical development of the concern exercised by the public institutions of a country for the food taken by their citizens, through care for its safety and proper testing by authorized governmental institutions, is presented. In the USA, FDA was established for this purpose, whereas European Union agencies are in charge in Europe. Additives are listed and classified according to E-number groups introduced in the European Union in 1990. Difference between the additives and supplements is explained. Special reference is given to an anonymous leaflet that appeared in Zagreb in the autumn 2000, in which some additives were described as harmful, detrimental, carcinogenic and highly hazardous, providing no valid arguments for such a statement. The author considers it merely an unargumented propaganda attack on particular European food manufactures. PMID:12398024

Zivkovi?, R

2001-01-01

388

Fluid loss additive  

SciTech Connect

A fluid loss additive and method are shown for use in cementing oil and gas well bores which comprises the reaction product of a polyamine compound and a high molecular weight sulfonated polymer. The polyamine and high molecular weight sulfonated polymer are prereacted in solution and dried to form a dry product which can be added to the dry cement blend on the shelf or added to the mixing water during the formation of the cement slurry at the well site. The prereacted additive is effective to control fluid loss in cement slurries at 350/sup 0/ F. and higher.

McKenzie, L.F.

1984-09-04

389

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. PMID:1175566

Deanin, R D

1975-01-01

390

Additional information: Anthropology  

E-print Network

Additional information: Anthropology: Dr. De Ann Pendry dpendry@utk.edu 865.974.4408 Department of Anthropology 250 South Stadium Hall Spanish: Dr. Óscar Rivera-Rodas oriverar@utk.edu 865.974.7005 Department academic tracks: Latin American Anthropology (taught in English), and Language and Latin American

Tennessee, University of

391

Diesel fuel additive  

SciTech Connect

This patent describes a diesel fuel additive composition. It comprises about 6.0 weight percent di-tertiary butyl peroxide, about 1.0 weight percent tall oil fatty imidazoline, about 0.5 weight percent neo decanoic acid, the balance being a hydrocarbon solvent carrier.

Vataru, M.; Filowitz, M.S.

1989-08-15

392

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.

393

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

394

Additional Sources of Information  

Cancer.gov

Additional Sources of Information Developing Medical Imaging Drug and Biological Products Part 1: Conducting Safety Assessments [PDF] (Issued 6/17/2004, Posted 6/17/2004) Part 2: Clinical Indications [PDF] (Issued 6/17/2004, Posted 6/17/2004) Content

395

High Speed Decimal Addition  

Microsoft Academic Search

Parallel decimal arithmetic capability is becoming increasingly attractive with new applications of computers in a multi-programming environment. The direct production of decimal sums offers a significant improvement in addition over methods requiring decimal correction. These techniques are illustrated in the eight-digit adder which appears in the System\\/360 Model 195.

M. S. Schmookler; A. Weinberger

1971-01-01

396

The partial space qualification of a vertically aligned carbon nanotube coating on aluminium substrates for EO applications.  

PubMed

The fabrication of NanoTube Black, a Vertically Aligned carbon NanoTube Array (VANTA) on aluminium substrates is reported for the first time. The coating on aluminium was realised using a process that employs top down thermal radiation to assist growth, enabling deposition at temperatures below the substrate's melting point. The NanoTube Black coatings were shown to exhibit directional hemispherical reflectance values of typically less than 1% across wavelengths in the 2.5 µm to 15 µm range. VANTA-coated aluminium substrates were subjected to space qualification testing (mass loss, outgassing, shock, vibration and temperature cycling) before their optical properties were re-assessed. Within measurement uncertainty, no changes to hemispherical reflectance were detected, confirming that NanoTube Black coatings on aluminium are good candidates for Earth Observation (EO) applications. PMID:24664077

Theocharous, Evangelos; Chunnilall, Christopher J; Mole, Ryan; Gibbs, David; Fox, Nigel; Shang, Naigui; Howlett, Guy; Jensen, Ben; Taylor, Rosie; Reveles, Juan R; Harris, Oliver B; Ahmed, Naseer

2014-03-24

397

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

398

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

399

Functional Generalized Additive Models.  

PubMed

We introduce the functional generalized additive model (FGAM), a novel regression model for association studies between a scalar response and a functional predictor. We model the link-transformed mean response as the integral with respect to t of F{X(t), t} where F(·,·) is an unknown regression function and X(t) is a functional covariate. Rather than having an additive model in a finite number of principal components as in Müller and Yao (2008), our model incorporates the functional predictor directly and thus our model can be viewed as the natural functional extension of generalized additive models. We estimate F(·,·) using tensor-product B-splines with roughness penalties. A pointwise quantile transformation of the functional predictor is also considered to ensure each tensor-product B-spline has observed data on its support. The methods are evaluated using simulated data and their predictive performance is compared with other competing scalar-on-function regression alternatives. We illustrate the usefulness of our approach through an application to brain tractography, where X(t) is a signal from diffusion tensor imaging at position, t, along a tract in the brain. In one example, the response is disease-status (case or control) and in a second example, it is the score on a cognitive test. R code for performing the simulations and fitting the FGAM can be found in supplemental materials available online. PMID:24729671

McLean, Mathew W; Hooker, Giles; Staicu, Ana-Maria; Scheipl, Fabian; Ruppert, David

2014-01-01

400

Functional Generalized Additive Models  

PubMed Central

We introduce the functional generalized additive model (FGAM), a novel regression model for association studies between a scalar response and a functional predictor. We model the link-transformed mean response as the integral with respect to t of F{X(t), t} where F(·,·) is an unknown regression function and X(t) is a functional covariate. Rather than having an additive model in a finite number of principal components as in Müller and Yao (2008), our model incorporates the functional predictor directly and thus our model can be viewed as the natural functional extension of generalized additive models. We estimate F(·,·) using tensor-product B-splines with roughness penalties. A pointwise quantile transformation of the functional predictor is also considered to ensure each tensor-product B-spline has observed data on its support. The methods are evaluated using simulated data and their predictive performance is compared with other competing scalar-on-function regression alternatives. We illustrate the usefulness of our approach through an application to brain tractography, where X(t) is a signal from diffusion tensor imaging at position, t, along a tract in the brain. In one example, the response is disease-status (case or control) and in a second example, it is the score on a cognitive test. R code for performing the simulations and fitting the FGAM can be found in supplemental materials available online. PMID:24729671

McLean, Mathew W.; Hooker, Giles; Staicu, Ana-Maria; Scheipl, Fabian; Ruppert, David

2014-01-01

401

Protective Role of Lithium in Ameliorating the Aluminium-induced Oxidative Stress and Histological Changes in Rat Brain  

Microsoft Academic Search

This study was carried out to investigate the effects of lithium (Li) supplementation on aluminium (Al) induced changes in\\u000a antioxidant defence system and histoarchitecture of cerebrum and cerebellum in rats. Al was administered in the form of aluminium\\u000a chloride (100 mg\\/kg b.wt.\\/day, orally) and Li was given in the form of Li carbonate through diet (1.1 g\\/kg diet, daily) for\\u000a a period

Punita Bhalla; D. K. Dhawan

2009-01-01

402

Reversal of an aluminium induced alteration in redox status in different regions of rat brain by administration of centrophenoxine.  

PubMed

Aluminium is one of the most studied neurotoxin, and its effects on nervous system are both structural and functional, involving various regions of brain. Aluminium toxicity is known to have multiple mechanisms of action in the central nervous system. Affinity of aluminium for thiol substrates is considered a possible molecular mechanism involved in aluminium neurotoxicity. The reduced glutathione (GSH) is especially important for cellular defence against aluminium toxicity. This study pertains to the modulatory action of centrophenoxine on GSH status in aluminium exposed different brain regions of the female rats. Aluminium was administered orally at a dose of 40 mg/Kg x b x wt x /day for a period of eight weeks whereas, centrophenoxine was administered intraperitoneally at a dose of 100 mg/Kg x b x wt x /day for a period of six weeks. The study was carried out in different regions of brain namely cerebrum, cerebellum, medulla oblongata and hypothalamus. Animals exposed to aluminum, registered a significant decrease in the levels of reduced glutathione, and oxidized glutathione as well as in the activity of glutathione reductase in all the different regions studied when compared to normal control animals. Post-treatment with centrophenoxine, showed a significant improvement in the thiol levels in different regions. Centrophenoxine when administered alone also had a profound effect on the levels of reduced glutathione as well as on the activity of glutathione reductase. From the present results, it can be stated that centrophenoxine administration, as a thiol-antioxidant, arrests the aluminium induced cellular damage by improving the thiol status in brain regions. PMID:16969688

Nehru, Bimla; Bhalla, Punita

2006-10-01

403

A study of enhanced diffusion during high dose high flux pulsed metal ion implantation into steel and aluminium  

Microsoft Academic Search

The depth profiles of metal ions implanted into steel and aluminium were measured by Rutherford backscattering (RBS). The ions of Mo, W and Y, produced by a metal vapour vacuum arc ion source (MEVVA) were implanted at an energy range from 25 to 50 keV for doses of (2-5)×1017 cm-2 into H13 steel and aluminium. Beam currents were from 0.5

Zhang Tonghe; Ji Chengzhou; Shen Jinghua; Chen Jun

1992-01-01

404

New aluminium-rich alkali slag matrix with clay minerals for immobilizing simulated radioactive Sr and Cs waste  

NASA Astrophysics Data System (ADS)

A new aluminium-rich alkali-activated slag matrix (M-AAS) with clay absorbents has been developed for immobilization of simulated radioactive Sr or Cs waste by introducing metakaolin, natural zeolite and NaOH-treated attapulgite clay minerals into alkali-activated slag matrix (AAS). The results revealed that the additions of metakaolin and clay absorbents into the cementitious matrixes would greatly enhance the distribution ratio, Rd, of selective adsorption whether the matrix was OPC matrix or AAS matrix. The new immobilizing matrix M-AAS not only exhibited the strongest selective adsorption for both Sr and Cs ions, but also was characterized by lower porosity and small pore diameter so that it exhibited the lowest leaching rate. Hydration product analyses also demonstrated that (Na+Al)-substituted C-S-H(I) and self-generated zeolite were major hydration products in the M-AAS matrix, which provided this new immobilizing matrix with better selective adsorption on Sr and Cs and lower leaching rate.

Qian, Guangren; Sun, Darren Delai; Tay, Joo Hwa

2001-12-01

405

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...

2012-08-15

406

Color Chips-Addition  

NSDL National Science Digital Library

This interactive Java applet helps the learner conceptualize the addition of signed numbers. The user clicks and drags red and black colored chips to a circle to represent a problem and then simplifies by placing a red negative chip on top of a positive black chip. The student actually sees the opposite pair disappear. Users may practice problems generated by the computer, themselves or free play with the chips. There are separate tabs to access information for the learner, the instructor and to seek help.

2005-01-01

407

Investigation of femtosecond collisional ionization rates in a solid-density aluminium plasma  

NASA Astrophysics Data System (ADS)

The rate at which atoms and ions within a plasma are further ionized by collisions with the free electrons is a fundamental parameter that dictates the dynamics of plasma systems at intermediate and high densities. While collision rates are well known experimentally in a few dilute systems, similar measurements for nonideal plasmas at densities approaching or exceeding those of solids remain elusive. Here we describe a spectroscopic method to study collision rates in solid-density aluminium plasmas created and diagnosed using the Linac Coherent light Source free-electron X-ray laser, tuned to specific interaction pathways around the absorption edges of ionic charge states. We estimate the rate of collisional ionization in solid-density aluminium plasmas at temperatures ~30?eV to be several times higher than that predicted by standard semiempirical models.

Vinko, S. M.; Ciricosta, O.; Preston, T. R.; Rackstraw, D. S.; Brown, C. R. D.; Burian, T.; Chalupský, J.; Cho, B. I.; Chung, H.-K.; Engelhorn, K.; Falcone, R. W.; Fiokovinini, R.; Hájková, V.; Heimann, P. A.; Juha, L.; Lee, H. J.; Lee, R. W.; Messerschmidt, M.; Nagler, B.; Schlotter, W.; Turner, J. J.; Vysin, L.; Zastrau, U.; Wark, J. S.

2015-03-01

408

Laser Surface Pre-treatment of Aluminium for Hybrid Joints with Glass Fibre Reinforced Thermoplastics  

NASA Astrophysics Data System (ADS)

Lightweight construction is a major trend in the automotive industry. Theconnection of fibre reinforced plastics with aluminium is consequently seen as promising prospect. In this regard, thermal joining can be applied for bonding of such hybrid joints. But in order to create a load bearing metal plastic joint, the surface of the metal has to be pre-treated. Recent research has shown that with laser surface pre-treatment high joint strengths are obtained. Yet there are a variety of laser sources and manufacturable surface topographies with structure sizes ranging from macroscopic to nanoscopic profiles. Within this work,macroscopic, microscopic and nanoscopic laser processed structures are created on aluminium and consequently joined to glass fibre reinforced thermoplastics of different fibre length and fibre content. High shear tensile strengths of up to 42 N/mm2 were obtained depending on the allocated material and the surface pre-treatment.

Heckert, André; Zaeh, Michael F.

409

Unequivocal identification of intracellular aluminium adjuvant in a monocytic THP-1 cell line  

PubMed Central

Aluminium-based adjuvants (ABA) are the predominant adjuvants used in human vaccinations. While a consensus is yet to be reached on the aetiology of the biological activities of ABA several studies have identified shape, crystallinity and size as critical factors affecting their adjuvanticity. In spite of recent advances, the fate of ABA following their administration remains unclear. Few if any studies have demonstrated the unequivocal presence of intracellular ABA. Herein we demonstrate for the first time the unequivocal identification of ABA within a monocytic T helper 1 (THP-1) cell line, using lumogallion as a fluorescent molecular probe for aluminium. Use of these new methods revealed that particulate ABA was only found in the cell cytoplasm. Transmission electron microscopy revealed that ABA were contained within vesicle-like structures of approximately 0.5–1??m in diameter. PMID:25190321

Mold, Matthew; Eriksson, Håkan; Siesjö, Peter; Darabi, Anna; Shardlow, Emma; Exley, Christopher

2014-01-01

410

Comparison of nickel silicide and aluminium ohmic contact metallizations for low-temperature quantum transport measurements.  

PubMed

We examine nickel silicide as a viable ohmic contact metallization for low-temperature, low-magnetic-field transport measurements of atomic-scale devices in silicon. In particular, we compare a nickel silicide metallization with aluminium, a common ohmic contact for silicon devices. Nickel silicide can be formed at the low temperatures (<400°C) required for maintaining atomic precision placement in donor-based devices, and it avoids the complications found with aluminium contacts which become superconducting at cryogenic measurement temperatures. Importantly, we show that the use of nickel silicide as an ohmic contact at low temperatures does not affect the thermal equilibration of carriers nor contribute to hysteresis in a magnetic field. PMID:21968083

Polley, Craig M; Clarke, Warrick R; Simmons, Michelle Y

2011-01-01

411

Modification of anodised aluminium surfaces using a picosecond fibre laser for printing applications.  

PubMed

The use of an ultrafast fibre laser at a wavelength of 1064 nm has allowed the surface modification of anodised aluminium plates coated with a 2 micron thick anodised layer for potential industrial applications. The micro- and nano-scale structuring of the anodised aluminium using picosecond pulses of approximately 25 ps duration at 200 kHz repetition rate was investigated. The interaction of the laser with the substrate created a hydrophilic surface, giving a contact angle of less than 10 degrees. On examination under a Scanning Electron Microscope (SEM), a morphology created due to laser induced spallation was observed. It has been found that these laser processed hydrophilic surfaces revert to a hydrophobic state with time. This has potential for application in the printing industry and offers reusability and sustainability of the process materials. This has been confirmed in initial trials. PMID:22905556

Ansari, I A; Watkins, K G; Sharp, M C; Hutchinson, R A; Potts, R M; Clowes, J

2012-06-01

412

Aluminium and hydrogen ions inhibit a mechanosensory calcium-selective cation channel  

NASA Technical Reports Server (NTRS)

The tension-dependent activity of mechanosensory calcium-selective cation channels in excised plasmalemmal patches from onion bulb scale epidermis is modulated by pH in the physiologically meaningful range between 4.5 and 7.2. It is rapidly lowered by lowering pH and rapidly raised by raising pH. Channel activity is effectively inhibited by low levels of aluminium ions and activity can be partially restored by washing for a few minutes. We suggest that under normal conditions the sensitivity of the mechanosensory channels to pH of the wall free space plays important roles in regulation of plant activities such as growth. We further suggest that, when levels of acid and aluminium ions in the soil solution are high, they might inhibit similar sensory channels in cells of the root tip, thus contributing critically to the acid soil syndrome.

Ding, J. P.; Pickard, B. G.

1993-01-01

413

Phosphate sensor based on immobilized aluminium-morin in poly (glycidyl methacrylate) microspheres  

NASA Astrophysics Data System (ADS)

This paper reports the development of dihydrogen phosphate ion (H2PO4-) sensor in free solution and immobilized aluminium-morin (Al-Mo) complex on poly(glycidyl methacrylate) (pGMA) microspheres. The immobilization was carried out by suspension photopolymerization technique. Based on Al-Mo solution work, phosphate can be detected from 0.1 - 15.0 ppm of dihydrogen phosphate at pH 5. Phosphate detection only takes about 5 minutes. Morphology analyses showed that the immobilization of Aluminium-Morin complex maintained the size of the microspheres and proved that entrapment involves in the formation of the microspheres. This result is further explained by Attenuated Total Reflectance (ATR) spectrum which does not show any formation of new bands. The microspheres were then used for further applications.

Ahmad, Amalina; Hanifah, Sharina Abu; Hasbullah, Siti Aishah; Suhud, Khairi; Zaini, Norhadisah Mohd; Heng, Lee Yook

2014-09-01

414

Microstructure heterogeneity after the ECAP process and its influence on recrystallization in aluminium  

SciTech Connect

The main purpose of the present work is to describe the qualitative and quantitative behaviours of aluminium during high strain plastic deformation and the effect of deformation on the subsequent recrystallization process. An Electron Backscatter Diffraction analysis of aluminium after the Equal channel angular pressing (ECAP) and recrystallization process is presented. In order to do this, several topological maps are measured for samples processed by 4 and 8 passes and recrystallized. The processing was conducted with route C. For all samples, distributions of grain size, misorientation, image quality factor (IQ) and texture were preceded and then analysed in some detail. - Highlights: ? Describe the microstructure fragmentation in aluminum. ? High strain plastic deformation and effect of deformation on recrystallization. ? The microstructure fragmentation and its influence on recrystallization. ? Image quality factor and misorientation characteristics are examined using EBSD.

Wronski, S., E-mail: wronski@fis.agh.edu.pl [Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Kraków (Poland); Tarasiuk, J., E-mail: tarasiuk@ftj.agh.edu.pl [Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Kraków (Poland); Bacroix, B., E-mail: brigitte.bacroix@univ-paris13.fr [LPMTM-CNRS, Université Paris XIII, 99, av. J.B. Clement, 93 430 Villetaneuse (France); Wierzbanowski, K., E-mail: wierzban@ftj.agh.edu.pl [Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Kraków (Poland); Paul, H., E-mail: nmpaul@imim-pan.krakow.pl [Institute of Metallurgy and Materials Science of Polish Academy of Sciences, Reymonta Street 25, 30-059 Kraków (Poland)

2013-04-15

415

Recovery of actinides from actinide-aluminium alloys by chlorination: Part II  

NASA Astrophysics Data System (ADS)

A chlorination route is being investigated for recovery of actinides from actinide-aluminium alloys, which originate from pyrochemical recovery of actinides from spent metallic nuclear fuel by electrochemical methods in molten LiCl-KCl. In the present work, the most important steps of this route were experimentally tested using U-Pu-Al alloy prepared by electrodeposition of U and Pu on solid aluminium plate electrodes. The investigated processes were vacuum distillation for removal of the salt adhered on the electrode, chlorination of the alloy by chlorine gas and sublimation of the AlCl3 formed. The processes parameters were set on the base of a previous thermochemical study and an experimental work using pure UAl3 alloy. The present experimental results indicated high efficiency of salt distillation and chlorination steps, while the sublimation step should be further optimised.

Sou?ek, P.; Cassayre, L.; Eloirdi, R.; Malmbeck, R.; Meier, R.; Nourry, C.; Claux, B.; Glatz, J.-P.

2014-04-01

416

Fabrication of Nano-Composite Surface Layers on Aluminium Employing Friction Stir Processing Technique  

SciTech Connect

Al/Al{sub 2}O{sub 3} nano-composite surface layer was fabricated via friction stir processing technique. Commercial AA6082 aluminium alloy extruded bar and nanometric Al{sub 2}O{sub 3} powder were subjected to friction stir processing at a substrate travel speed of 80 mm/min and a tool rotation speed of 1000 rpm using a hardened H-13 tool steel. The grain structure and reinforcement particles were investigated by using optical and scanning electron microscopy. Results show that Al{sub 2}O{sub 3} particles can be more uniformly dispread in aluminium substrate by increasing the number of processing passes. Also, hardness enhancement of the nano-composite surface layer was found. This is attributed to uniform dispersion of Al{sub 2}O{sub 3} particles.

Bozorg, S. F. K.; Zarghani, A. S.; Zarei-Hanzaki, A. [School of Metallurgy and Materials Engineering, Faculty of Engineering, University of Tehran, Tehran, P.O. Box: 14395-553 (Iran, Islamic Republic of)

2010-03-11

417

Numerical simulation of plasmonic effects in amorphous silicon induced by embedded aluminium nanoparticles  

NASA Astrophysics Data System (ADS)

This work reports a theoretical study aimed to identify the plasmonic resonance condition for a system formed by metallic nanoparticles embedded in an a-Si:H matrix. The study is based on a Tauc-Lorentz model for the electrical permittivity of a-Si:H and a Drude model for the metallic nanoparticles. It is calculated the The polarizability of an sphere and ellipsoidal shaped metal nanoparticles with radius of 20 nm. We also performed FDTD simulations of light propagation inside this structure reporting a comparison among the effects caused by a single nanoparticles of Aluminium, Silver and, as a comparison, an ideally perfectly conductor. The simulation results shows that is possible to obtain a plasmonic resonance in the red part of the spectrum (600-700 nm) when 20-30 nm radius Aluminium ellipsoids are embedded into a-Si:H.

Fantoni, A.; Leão, H.; Louro, P.; Fernandes, M.; Vygranenko, Y.; Vieira, M.

2015-02-01

418

Fabrication of self-healing super-hydrophobic surfaces on aluminium alloy substrates  

NASA Astrophysics Data System (ADS)

We present a method to fabricate a super-hydrophobic surface with a self-healing ability on an aluminium alloy substrate. The coatings are obtained by combining a two-step process (first, the substrate is immersed in a solution of HCl, HF and H2O, and then in boiling water) and succeeding surface fluorination with a solution of poly(vinylidene-fluoride-co-hexafluoropropylene) and a fluoroalkyl silane. The morphological features and chemical composition were studied by scanning electron micrometry and energy-dispersive X-ray spectroscopy. The prepared super-hydrophobic aluminium surfaces showed hierarchical structures forming pores, petals and particles with a contact angle of 161° and a sliding angle of 3°.

Wang, Yang; Wei Liu, Xiao; Zhang, Hai Feng; Zhou, Zhi Ping

2015-04-01

419

Investigation of femtosecond collisional ionization rates in a solid-density aluminium plasma.  

PubMed

The rate at which atoms and ions within a plasma are further ionized by collisions with the free electrons is a fundamental parameter that dictates the dynamics of plasma systems at intermediate and high densities. While collision rates are well known experimentally in a few dilute systems, similar measurements for nonideal plasmas at densities approaching or exceeding those of solids remain elusive. Here we describe a spectroscopic method to study collision rates in solid-density aluminium plasmas created and diagnosed using the Linac Coherent light Source free-electron X-ray laser, tuned to specific interaction pathways around the absorption edges of ionic charge states. We estimate the rate of collisional ionization in solid-density aluminium plasmas at temperatures ~30?eV to be several times higher than that predicted by standard semiempirical models. PMID:25731816

Vinko, S M; Ciricosta, O; Preston, T R; Rackstraw, D S; Brown, C R D; Burian, T; Chalupský, J; Cho, B I; Chung, H-K; Engelhorn, K; Falcone, R W; Fiokovinini, R; Hájková, V; Heimann, P A; Juha, L; Lee, H J; Lee, R W; Messerschmidt, M; Nagler, B; Schlotter, W; Turner, J J; Vysin, L; Zastrau, U; Wark, J S

2015-01-01

420

Fatigue damage rule of LY12CZ aluminium alloy under sequential biaxial loading  

NASA Astrophysics Data System (ADS)

A series of biaxial two-level variable amplitude loading tests are conducted on smooth tubular specimens of LY12CZ aluminium alloy. The loading paths of 90° out-of-phase, 45° out-of-phase and 45° in-phase are utilized. The fatigue damage cumulative rules under two-level step loading of three loading paths are analyzed. By introducing a parameter ? which is a function of the phase lag angle between the axial and the torsional loading, a new multiaxial nonlinear fatigue damage cumulative model is proposed. The proposed model is evaluated by the experimental data for two-level loading, multi-level loading of LY12CZ aluminium alloy, and multi-level loading of 45 steel. Fatigue lives predicted are within a factor of 2 scatter band.

Wang, YingYu; Zhang, DaChuan; Yao, WeiXing

2014-01-01

421

A sensitive, rapid and inexpensive method to assess aluminium(III) ions in technetium eluates.  

PubMed

The aim of the study was to validate a semiquantitative analytical method to identify the aluminium(III) [Al(III)] concentration in 99Mo/99mTc generator eluates to check the European Pharmacopoeia (Ph. Eur.) requirement (<5 ?g/ml). Three different solutions measuring 20 ml - 0.2% 1,10-phenanthroline, 0.05% chrome azurol S and 20% hexamethylenetetramine - were prepared. A cellulose filter paper was subsequently immersed in them, dried overnight at room temperature and cut into rectangles. A volume of 5 ?l of first eluates of various 99Mo/99mTc generators was placed onto a reagent paper and the spot colour was compared with a standard aluminium solutions scale (0-100 ?g/ml). A cyan/magenta/yellow/key (CMYK) model analysis was adapted to quantify the intensity of colour on the paper, and the presence of aluminium in the eluates was detected by a spectrophotometer. Small changes in standard solution pH (4.1-5.2) and chrome azurol S concentration did not affect the analysis. The cyan channel image analysis was proportional to the Al3+ solution concentration (y=25 019x+1489, R2=0.9554 within 2.5-8 ?g/ml). The detection limit for aluminium by the visual test method is about 1 ?g/ml, and fading is absent. The cyan channel image analysis method is independent of the observer and is applicable for the evaluation of the chemical purity of 99Mo/99mTc generator eluates. Our colorimetric 'spot test' is advantageous for the visual evaluation of Al pertechnetate concentrations as required by Ph. Eur. showing a sensitivity and a limit of detection superior to that of commercially available spot systems. PMID:24681768

Buroni, Federica E; Lodola, Lorenzo; Persico, Marco G; Aprile, Carlo

2014-07-01

422

Operational Use of the Environmental Accounting and Information Software TEAMS at Hydro Aluminium Sunndal, Norway  

Microsoft Academic Search

This paper presents findings of an intrinsic case study about how Hydro Aluminium Sunndal, Norway (HAS) implemented a environmental\\u000a management accounting tool (Total Environmental Accounting and Managements System, TEAMS) in 2003. The case study focussed\\u000a on how TEAMS could be implemented as an effective information and reporting tool at HAS.\\u000a \\u000a HAS is located in Møre and Romsdal, western Norway, and

John E. Hermansen; Anne Kristine Mølmen-Nertun; Grunde Pollestad

423

Corrosion behaviour of high aluminium steels in molten carbonate in an anode gas environment  

Microsoft Academic Search

The corrosion behaviour of five ferritic steels with high aluminium content was investigated in (Li0.60\\/Na0.40)CO3 melt in three different anode gas environments. The corrosion potentials were measured versus time, and the electrochemical techniques used for determination of the corrosion rates were linear polarisation resistance and Tafel extrapolation. The corrosion layer formed on the surface after electrochemical tests have been analysed

Göran Lindbergh; Baohua Zhu

2001-01-01

424

Wear of a spray-deposited hypereutectic aluminium-silicon alloy  

Microsoft Academic Search

This paper compares the wear characteristics of hypereutectic aluminium-silicon alloys processed using two different routes: the more recent spray-deposition technique and the conventional casting process. Unlubricated pin-on-disk wear tests revealed that the spray-deposited alloy has a better resistance to wear than its conventionally-cast counterpart. It is suggested that the increased hardness and the uniform distribution of the fine second phase

S. C. Lim; M. Gupta; Y. F. Leng; E. J. Lavernia

1997-01-01

425

Passivating oxide film and growing characteristics of anodic coatings on aluminium alloys  

NASA Astrophysics Data System (ADS)

The paper studies some aspects of the behaviour of four aluminium alloys under chemical etching by sodium hydroxide solution and during their subsequent anodizing in sulphuric acid solution. A correspondence is seen between etching rate, thickness of the passivating oxide film and porosity of the anodic layer. The possibility of an influence on these properties of precipitates and micro-heterogeneities in the metallic surface is suggested.

Feliu, S.; Bartolomé, M. a.. J.; González, J. A.; López, V.; Feliu, S.

2008-02-01

426

Bioavailability and Toxicity of Freshly Neutralized Aluminium to the Freshwater Crayfish Pacifastacus leniusculus  

Microsoft Academic Search

Freshly neutralized aluminium (Al) is toxic to a variety of freshwater organisms despite its insolubility at circumneutral pH. Insoluble Al acts exogenously—for example, on the fish gill—thereby impairing respiratory function, and endogenously in grazing and filter-feeding invertebrates following ingestion during drinking and feeding. This paper examines the bioavailability and behavioral toxicity of freshly neutralized Al to the freshwater crayfish Pacifastacus

E. Alexopoulos; C. R. McCrohan; J. J. Powell; R. Jugdaohsingh; K. N. White

2003-01-01

427

Aluminium triggers malate-independent potassium release via ion channels from the root apex in wheat  

Microsoft Academic Search

The regulatory mechanisms for the aluminium (Al)-induced efflux of K+ and malate from the root apex of Al-resistant wheat (Triticum aestivum L. cv. Atlas) were characterized. Treatment with 20 mM tetraethylammonium (TEA) chloride, a K+-channel inhibitor, blocked the Al-induced K+ efflux by 65%, but blocked the Al-induced malate efflux only slightly. Lanthanum (La3+) or ytterbium (Yb3+) strongly inhibited the K+

Hiroki Osawa; Hideaki Matsumoto

2002-01-01

428

Finite element analysis of plastic failure in heat-affected zone of welded aluminium connections  

Microsoft Academic Search

Finite element analyses of plastic failure in the heat-affected zone of a generic welded aluminium connection are presented. The analyses include process history through multi-scale modelling. The heterogeneous material properties of the heat-affected zone are calculated using welding simulations to obtain the temperature history as input to coupled precipitation, yield strength and work-hardening models. Thermal history-dependent material parameters are mapped

Cato Dørum; Odd-Geir Lademo; Ole Runar Myhr; Torodd Berstad; Odd Sture Hopperstad

2010-01-01

429

Surface modification of steel and cast iron to improve corrosion resistance in molten aluminium  

Microsoft Academic Search

In the present investigation, molten aluminium corrosion tests have been performed on boronised samples of duplex 22Cr–5Ni stainless steel, hot work steel (AISI H13) and nodular cast iron, and on a non-boronised ?-TiAl sample as a reference. The experimental results show that the corrosion rate, as expressed in terms of volume loss per square centimetre of the specimen per hour,

D. C. Lou; O. M. Akselsen; M. I. Onsøien; J. K. Solberg; J. Berget

2006-01-01

430

Quasi-brittle fracture during structural impact of AA7075-T651 aluminium plates  

Microsoft Academic Search

The stress–strain behaviour of the aluminium alloy 7075 in T651 temper is characterized by tension and compression tests. The material was delivered as rolled plates of thickness 20 mm. Quasi-static tension tests are carried out in three in-plane directions to characterize the plastic anisotropy of the material, while the quasi-static compression tests are done in the through-thickness direction. Dynamic tensile tests

Tore Børvik; Odd Sture Hopperstad; Ketill O. Pedersen

2010-01-01

431

Characterisation of organic–inorganic hybrid coatings deposited on aluminium substrates  

Microsoft Academic Search

Optically transparent silica-based single amorphous phase organic–inorganic hybrid coating materials with differing organic\\/inorganic ratios have been prepared by a novel patented sol–gel process and deposited using a simple angled flow coating method on commercially pure aluminium substrates. Transmission electron microscopy and scanning electron microscopy were used to characterise the microstructures of the hybrid materials and the quality of the interfaces

Yung-Hoe Han; Alan Taylor; Kevin M. Knowles

2008-01-01

432

Analysis of natural convective heat transfer of nano coated aluminium fins using Taguchi method  

NASA Astrophysics Data System (ADS)

Rectangular aluminium fins were preferred for analysis and coated by carbon nano tubes using PVD to enhance the heat transfer rate of fins. Convective heat transfer rates for coated and non-coated surfaces were calculated and compared. The temperature and heat transfer characteristics were investigated using Nusselt, Grashof, Prandtl and Rayleigh numbers and also optimized by Taguchi method and ANOVA analysis. The average percentage of increase in fin efficiency is 5 %.

Senthilkumar, R.; Nandhakumar, A. J. D.; Prabhu, S.

2013-01-01

433

Simulation of distortion due to non-uniform cooling in aluminium extrusion process  

Microsoft Academic Search

Cooling subsequent to extrusion process is a crucial operation in aluminium extrusion value chain. Nonuniform cooling induced\\u000a shape distortion, such as deflection, twisting and etc., is a challenge for manufacturers. Temperature management is therefore\\u000a a key to this process. Appropriate modelling, using both physical and numerical methods, can help us achieve a better temperature\\u000a control in extrusion plants. In this

S. Bikass; B. Andersson; A. Pilipenko

2010-01-01

434

The role of PVD TiN coating in wear behaviour of aluminium extrusion die  

Microsoft Academic Search

In this study, the wear behaviour and surface properties of a PVD TiN coated extrusion die were investigated. Both an extrusion die for aluminium profiles and the samples manufacturing from AISI H13 steel were hardened, tempered, nitrided and TiN coated by PVD method. The microhardnesses on the coated surface and cross-section of both nitrided and coated samples were determined. The

M. B. Karami?; H. Sert

1998-01-01

435

Crashworthiness of aluminium extrusions: validation of numerical simulation, effect of mass ratio and impact velocity  

Microsoft Academic Search

Based on an experimental database obtained from static and dynamic tests on square aluminium extrusions in alloy AA6060 tempers T4 and T6, a numerical model using the LS-DYNA computer code was validated. Excellent predictions of the response of the tubes were found by using isotropic elasticity, the von Mises yield criterion, the associated flow rule and non-linear isotropic strain hardening.

M. Langseth; O. S. Hopperstad; T. Berstad

1999-01-01

436

Retrogression and re-aging treatment on short transverse tensile properties of 7010 aluminium alloy extrusions  

Microsoft Academic Search

The influence of retrogression and re-aging treatment (RRA) on short transverse tensile properties of 7010 aluminium alloy extrusions was studied. The short transverse ductility of extrusions, which was much lower in the T6 condition, was improved to the optimum level after retrogression and re-aging treatment. It is found that short transverse ductility is influenced by the nature of precipitate particles

M. Angappan; V. Sampath; B. Ashok; V. P. Deepkumar

2011-01-01

437

Some studies on stresses and strains of aluminium alloy during extrusion-forging at room temperature  

Microsoft Academic Search

The present investigation has been undertaken to evaluate some aspects on extrusion-forging during cold upsetting using a suitable die using aluminium alloy (H9-6063) solid cylinders subjected to different geometrical conditions such as approaching angles namely, 35°, 45°, 50° and 60°, with two different initial protrusion heights namely 8mm and 10mm. During the experiments, three geometries such as barreled cylinder, truncated

R. Narayanasamy; K. Baskaran; D. Muralikrishna

2008-01-01

438

A process model for on-line quenching of aluminium extrusions  

Microsoft Academic Search

A complete process model for the cooling of aluminium extrusions is presented. It is capable of predicting both thermally\\u000a induced distortions and possible strength reductions. The model consists of three parts: a thermal part, a metallurgical part,\\u000a and a mechanical part. The thermal part includes heat-transfer and heat-conduction models and generates the temperature history\\u000a needed as input to the other

Niklas Järvstråt; Stig Tjøtta

1996-01-01

439

Fatigue strength of welded joints in 6N01 aluminium alloy extrusions  

Microsoft Academic Search

In this paper, the fatigue strength of welded joints in 6N01 aluminium alloy extrusions is discussed. Low copper content (?0.02%) alloys were chosen, considering corrosion resistance in sea water. Two series of specimens were prepared. One had two longitudinal stiffeners welded on both sides of the main plate (L?TYPE), and the other a non?load carrying fillet welded cruciform joint (T?TYPE).

K. Matsuoka; S. Chiaki; T. Uemura; K. Kamata

1994-01-01

440

The Relationship of Aluminium and Silver to Neural Tube Defects; a Case Control  

PubMed Central

Objective The purpose of this study was to identify the relationship of neurotoxic inorganic elements in the hair of patients with the diagnosis of Neural Tube Defects. Our initial hypothesis was that neurotoxic inorganic elements were associated with Neural Tube Defects. Methods Twenty-three samples of hair from newborns were obtained from the General Hospital, “Aurelio Valdivieso” in the city of Oaxaca, Mexico. The study group included 8 newborn infants with neural tube pathology. The control group was composed of 15 newborns without this pathology. The presence of inorganic elements in the hair samples was determined by inductively-coupled plasma spectroscopy (spectroscopic emission of the plasma). Findings The population of newborns with Neural Tube Defects showed significantly higher values of the following elements than the control group: Aluminium, Neural Tube Defects 152.77±51.06 µg/g, control group 76.24±27.89 µg/g; Silver, Neural Tube Defects 1.45±0.76, control group 0.25±0.53 µg/g; Potassium, Neural Tube Defects 553.87±77.91 µg/g, control group 341.13±205.90 µg/g. Association was found at 75 percentile between aluminium plus silver, aluminium plus potassium, silver plus potassium, and potassium plus sodium. Conclusion In the hair of newborns with Neural Tube Defects, the following metals were increased: aluminium, silver. Given the neurotoxicity of the same, and association of Neural Tube Defects with aluminum and silver, one may infer that they may be participating as factors in the development of Neural Tube Defects. PMID:23400307

Ramírez-Altamirano, María de Jesús; Fenton-Navarro, Patricia; Sivet-Chiñas, Elvira; Harp-Iturribarria, Flor de María; Martínez-Cruz, Ruth; Cruz, Pedro Hernández; Cruz, Margarito Martínez; Pérez-Campos, Eduardo

2012-01-01

441

Numerical simulation study of laser-driven shock wave propagation in planar aluminium foils  

Microsoft Academic Search

A comprehensive numerical simulation study of laser-driven shock wave propagation in planar aluminium foils, 20- 50mu m, is performed using the one-dimensional radiation hydrodynamic code MULTI. The effect of the spatial mesh size on the shock velocity and peak shock pressure is found to be significant and the optimum mesh size is obtained. Shock velocities and maximum pressure are calculated

V. K. Senecha; Jie Zhang; Wie Wang; H. C. Pant

2002-01-01

442

Simulation of hollow shaped charge jet impacts onto aluminium whipple bumpers at 11 km\\/s  

Microsoft Academic Search

The computational technique of Smoothed Particle Hydrodynamics (as implemented in the hydrocodes AUTODYN-2D and AUTODYN-3D) has been used to simulate the impact of hollow shaped charge jet projectiles onto stuffed Whipple bumper shielding. Due to limited availability of material models, the interim Nextel\\/Kevlar-Epoxy bumper was modelled as an equivalent thickness of aluminium. Stuffed Whipple bumper shields are used for meteoroid

Emma A. Taylor

2001-01-01

443

Solar thermal performance of a nickel-pigmented aluminium oxide selective absorber  

Microsoft Academic Search

The solar thermal performance of a nickel-pigmented aluminium oxide selective absorber was determined by using an experimental model (prototype model). The constructed models were tested outdoors during daylight under a clear sky. Different volumes of prototypes were used. The flat-plate collector used was of the glazed type. The thermodynamic characteristics of each flat-plate collector were determined. The maximum calculated collective

A Wazwaz; J Salmi; H Hallak; R Bes

2002-01-01

444

A study on ultra–high-speed cutting of aluminium alloy  

Microsoft Academic Search

To investigate the mechanism of ultra–high-speed cutting for aluminium alloy, cutting experiments by using a machine tool equipped with an active magnetic bearing spindle were performed over a range of cutting speeds from 20 to 260 m\\/s. On the whole, the finished surface tends to improve with an increase in cutting speed. However, the formation of welded metal on the

Reza Yousefi; Yoshio Ichida

2000-01-01

445

Mortality for Pancreatic Cancer Among Aluminium Smelter Workers in Sardinia, Italy  

Microsoft Academic Search

www.gimle.fsm.it To investigate the relationship between exposure to polycyclic aromatic hydrocarbons (PAHs) and mortality for specific cancer sites, 1152 men, employed for at least 1 year at a prebake aluminium smelter, were followed-up from 1972 until 31 December 2001. Exposure to PAHs was estimated from a detailed reconstruction of the working history experienced in the plant by each cohort member

P. Carta; G. Aru; C. Cadeddu; G. Gigli; G. Papi; F. Carta; P. Nurchis

2004-01-01

446

A mortality study among workers in a French aluminium reduction plant  

Microsoft Academic Search

Objective: A mortality study on the association between lung cancer and occupational exposure to polycyclic aromatic hydrocarbons (PAHs)\\u000a was carried out in a French aluminium reduction plant. This study updated a previous mortality study. Method: The historical cohort included every male worker who had been employed in the plant for at least 1?year between 1950 and\\u000a 1994. Workers were followed-up

J. J. Moulin; T. Clavel; B. Buclez; G. Laffitte-Rigaud

2000-01-01

447

A new testing machine to determine the behaviour of aluminium granulate under combined pressure and shear  

Microsoft Academic Search

To reduce the environmental impact and increase the yield from conventional aluminium recycling processes, a direct continuous\\u000a extrusion method of shredded scrap is being developed. The innovative method is a process where a rotating screw generates\\u000a the extrusion pressure, introducing rotation to the scrap compacting and extruding in one single operation. The objective\\u000a of this paper is to present a

Fredrik Widerøe; Torgeir Welo; Harald Vestøl

448

Numerical and experimental study of dry cutting for an aeronautic aluminium alloy (A2024-T351)  

Microsoft Academic Search

In the present contribution, numerical and experimental methodologies concerning orthogonal cutting are proposed in order to study the dry cutting of an aeronautic aluminium alloy (A2024-T351). The global aim concerns the comprehension of physical phenomena accompanying chip formation according to cutting velocity variation.For the numerical model, material behaviour and its failure criterion are based on the Johnson–Cook law. The model

Tarek Mabrouki; François Girardin; Muhammad Asad; Jean-François Rigal

2008-01-01

449

Aluminium-induced bone disease in uremic Rats: Effect of deferoxamine  

Microsoft Academic Search

We have previously established a rat model of chronic uremia, which is suitable to investigate the effect of various treatment modalities on renal osteodystrophy [1]. After four months subsequent to 5\\/6 nephrectomy, some animals were treated by gavage for 9 weeks with tap water (controls), or with aluminium (Al-citrate) 3 × 25 mg\\/week\\/kg b.wt ± subsequent deferoxamine (DFO) 3 ×

Greg Jablonski; Knut H. Klem; Carl Ch. Danielsen; Lis Mosekilde; Jan O. Gordeladze

1996-01-01

450

Synthesis and photophysical properties of aluminium tris-(4-morpholine-8-hydroxyquinoline)  

PubMed Central

Aluminium tris(4-morpholinyl-8-hydroxyquinoline) has been synthesized and characterized. The photoluminescence measurements showed that the new derivative is blue shifted and has relative photoluminescence quantum yield two times higher compared to the pristine Al tris(8-hydroxyquinoline). Deferential scanning colorimetric studies revealed that the newly synthesized Alq3 derivative in this work is amorphous material with the highest transition glass temperature value among the reported amorphous Alq3 derivatives. PMID:25685461

Omar, Walaa A.E.

2012-01-01

451

Synthesis and photophysical properties of aluminium tris-(4-morpholine-8-hydroxyquinoline).  

PubMed

Aluminium tris(4-morpholinyl-8-hydroxyquinoline) has been synthesized and characterized. The photoluminescence measurements showed that the new derivative is blue shifted and has relative photoluminescence quantum yield two times higher compared to the pristine Al tris(8-hydroxyquinoline). Deferential scanning colorimetric studies revealed that the newly synthesized Alq3 derivative in this work is amorphous material with the highest transition glass temperature value among the reported amorphous Alq3 derivatives. PMID:25685461

Omar, Walaa A E

2013-11-01

452

Infiltration-processed, functionally graded aluminium titanate\\/zirconia–alumina compositePart II Mechanical properties  

Microsoft Academic Search

The nature and degree of deformation-microfracture damage around Vickers indentations in a layered and graded aluminium titanate (AT)\\/(alumina–zirconia (AZ)) composite is studied. Samples with a homogeneous layer of AZ and a graded layer of heterogeneous AT\\/AZ are fabricated by an infiltration route. Depth profiling of the Vickers hardness shows that the hardness of the material is depth dependent with a

S. Pratapa; I. M Low

1998-01-01

453

Arsenic removal during conventional aluminium-based drinking-water treatment  

Microsoft Academic Search

The changing forms and concentrations of arsenic through aluminium-based coagulation treatment processes were tracked for three drinking-water treatment plants. This has provided direct evidence of where and how arsenic is removed. In general, soluble As(V) is converted to particulate As(V) by adsorption during rapid mixing, and is removed along with naturally occurring particulate arsenic predominantly by clarification. Soluble As(III) tracks

Jan Gregor

2001-01-01

454

Preparation of aluminium-fly ash particulate composite by powder metallurgy technique  

Microsoft Academic Search

Aluminium-fly ash mixtures containing different weight percentages of fly ash were prepared and compacted at pressures from\\u000a 138–414 MPa. The compacts prepared at 414 MPa were sintered in nitrogen atmosphere at 600, 625 and 645C, respectively. The\\u000a time of sintering ranged from 0.5–6 h. The densification parameter and the green densities of the compacts were determined\\u000a as a function of

R. Q Guo; P. K Rohatgi; D Nath

1997-01-01

455

Bond strength of pressure sensitive adhesives for CFRP aluminium-alloy hybrid beams under impact loading  

Microsoft Academic Search

This paper discusses the impact absorbing capabilities of CFRP aluminium-alloy hybrid beams bonded with double-coated pressure sensitive adhesive tapes. Two sorts of double-coated adhesive tapes (VHB and SBT, 3M) were used in experiments. The strength and absorbed energy of the beams under impact loading were measured using an instrumented Charpy tester. Using the beams having the different adhesive tapes and

C. Sato

2003-01-01

456

A microplasticity analysis of shear band cracks in rolled 2024 aluminium alloy  

Microsoft Academic Search

Flow localization in the form of shear bands is an important part of the ductile fracture process. The propagation of shear-band cracks has been followed in the rolling of an annealed and an aged-hardened 2024 aluminium alloy respectively. Shear bands occurred in the alloy that had been aged-hardened prior to rolling but not in the one that had been annealed.

W. B. Lee; K. C. Chan

1991-01-01

457

Effects of chelators on the acute toxicity and bioavailability of aluminium to Tetrahymena pyriformis  

Microsoft Academic Search

The acute toxic effects of aluminium (Al) to the ciliated protozoa Tetrahymena pyriformis GL (TP) were investigated after a short exposure of 9 h, a time which normally allowed three generations of T. pyriformis in control culture to be obtained. Al was administered under the soluble forms of three salts (AlCl3, Al(NO3)3, Al2(SO4)3) and the fine particles of an insoluble

M. P Sauvant; D Pepin; J Bohatier; C. A Groliere

2000-01-01

458

Aluminium ultrahigh vacuum system for the 3 GeV TPS synchrotron light source  

NASA Astrophysics Data System (ADS)

The 3-GeV Taiwan Photon Source (TPS) is a large accelerator and synchrotron light source of circumference 518.4 m. The electron storage ring of TPS requires an ultrahigh-vacuum pressure per beam current less than 2×10-10 Pa/mA in the beam duct to maintain a long life of the circulating beam without scattering of ions by residual gases. Aluminium alloys used for the beam ducts have a benefit of greater thermal conductivity that simplifies the structure of vacuum vessels built with the cooling components. Machining completely free of oil applied to the aluminium chambers followed by cleaning with ozonized water and welding in house provide a precise dimensional control within 0.3 mm and a clean surface with a small rate ~ 6.4×10-12 Pa m/s of thermal outgassing after baking at 150 °C for 24 h. The assembled ion pump with non-evaporable getter pump is capable of evacuating the chamber to a pressure < 1×10-9 Pa. The average pressure inside the duct is expected to be sufficiently small. The clean process to manufacture the aluminium ultrahigh vacuum system is described.

Hsiung, G. Y.; Chang, C. C.; Chen, C. L.; Wu, L. H.; Cheng, C. M.; Chan, C. K.; Yang, Y. C.; Hsueh, H. P.; Hsu, S. N.; Chen, J. R.

2013-06-01

459

Aluminium in an ocean general circulation model compared with the West Atlantic Geotraces cruises  

E-print Network

A model of aluminium has been developed and implemented in an Ocean General Circulation Model (NEMO-PISCES). In the model, aluminium enters the ocean by means of dust deposition. The internal oceanic processes are described by advection, mixing and reversible scavenging. The model has been evaluated against a number of selected high-quality datasets covering much of the world ocean, especially those from the West Atlantic Geotraces cruises of 2010 and 2011. Generally, the model results are in fair agreement with the observations. However, the model does not describe well the vertical distribution of dissolved Al in the North Atlantic Ocean. The model may require changes in the physical forcing and the vertical dependency of the sinking velocity of biogenic silica to account for other discrepancies. To explore the model behaviour, sensitivity experiments have been performed, in which we changed the key parameters of the scavenging process as well as the input of aluminium into the ocean. This resulted in a bet...

van Hulten, Marco; Tagliabue, Alessandro; Dutay, Jean-Claude; Gehlen, Marion; de Baar, Hein J W; Middag, Rob

2012-01-01

460

Recovery of actinides from actinide-aluminium alloys by chlorination: Part I  

NASA Astrophysics Data System (ADS)

Pyrochemical processes in molten LiCl-KCl are being developed in ITU for recovery of actinides from spent nuclear fuel. The fuel is anodically dissolved to the molten salt electrolyte and actinides are electrochemically reduced on solid aluminium cathodes forming solid actinide-aluminium alloys. A chlorination route is being investigated for recovery of actinides from the alloys. This route consists in three steps: Vacuum distillation for removal of the salt adhered on the electrode, chlorination of the actinide-aluminium alloys by chlorine gas and sublimation of the formed AlCl 3. A thermochemical study showed thermodynamic feasibility of all three steps. On the basis of the conditions identified by the calculations, experiments using pure UAl 3 alloy were carried out to evaluate and optimise the chlorination step. The work was focused on determination of the optimal temperature and Cl 2/UAl 3 molar ratio, providing complete chlorination of the alloy without formation of volatile UCl 5 and UCl 6. The results showed high efficient chlorination at a temperature of 150 °C.

Cassayre, L.; Sou?ek, P.; Mendes, E.; Malmbeck, R.; Nourry, C.; Eloirdi, R.; Glatz, J.-P.

2011-07-01

461

Recovery of aluminium, nickel-copper alloys and salts from spent fluorescent lamps  

SciTech Connect

This study explores a combined pyro-hydrometallurgical method to recover pure aluminium, nickel-copper alloy(s), and some valuable salts from spent fluorescent lamps (SFLs). It also examines the safe recycling of clean glass tubes for the fluorescent lamp industry. Spent lamps were decapped under water containing 35% acetone to achieve safe capture of mercury vapour. Cleaned glass tubes, if broken, were cut using a rotating diamond disc to a standard shorter length. Aluminium and copper-nickel alloys in the separated metallic parts were recovered using suitable flux to decrease metal losses going to slag. Operation variables affecting the quality of the products and the extent of recovery with the suggested method were investigated. Results revealed that total loss in the glass tube recycling operation was 2% of the SFLs. Pure aluminium meeting standard specification DIN 1712 was recovered by melting at 800 deg. C under sodium chloride/carbon flux for 20 min. Standard nickel-copper alloys with less than 0.1% tin were prepared by melting at 1250 deg. C using a sodium borate/carbon flux. De-tinning of the molten nickel-copper alloy was carried out using oxygen gas. Tin in the slag as oxide was recovered by reduction using carbon or hydrogen gas at 650-700 deg. C. Different valuable chloride salts were also obtained in good quality. Further research is recommended on the thermodynamics of nickel-copper recovery, yttrium and europium recovery, and process economics.

Rabah, Mahmoud A

2004-07-01

462

Can hazardous waste become a raw material? The case study of an aluminium residue: a review.  

PubMed

The huge number of research studies carried out during recent decades focused on finding an effective solution for the waste treatment, have allowed some of these residues to become new raw materials for many industries. Achieving this ensures a reduction in energy and natural resources consumption, diminishing of the negative environmental impacts and creating secondary and tertiary industries. A good example is provided by the metallurgical industry, in general, and the aluminium industry in this particular case. The aluminium recycling industry is a beneficial activity for the environment, since it recovers resources from primary industry, manufacturing and post-consumer waste. Slag and scrap which were previously considered as waste, are nowadays the raw material for some highly profitable secondary and tertiary industries. The most recent European Directive on waste establishes that if waste is used as a common product and fulfils the existing legislation for this product, then this waste can be defined as 'end-of-waste'. The review presented here, attempts to show several proposals for making added-value materials using an aluminium residue which is still considered as a hazardous waste, and accordingly, disposed of in secure storage. The present proposal includes the use of this waste to manufacture glass, glass-ceramic, boehmite and calcium aluminate. Thus the waste might effectively be recovered as a secondary source material for various industries. PMID:22071175

López-Delgado, Aurora; Tayibi, Hanan

2012-05-01

463

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

NASA Astrophysics Data System (ADS)

The motivation to reduce overall vehicle weight within the automotive sector drives the substitution of lightweight materials such as aluminium alloys for structural components. Such a substitution requires a significant amount of development to manufacture structurally parts such that the energy absorption characteristics are not sacrificed in the event of crash. The effects of the manufacturing processes on the crash performance of automotive structural components must be better understood to ensure improved crashworthiness. This paper presents results of an experimental and numerical investigation of the crash response and energy absorption properties of impacted hydroformed aluminium alloy tubes. Crash experiments on hydroformed tubes were performed using a deceleration sled test at the General Motors Technical Center. Results from axial crush testing showed that an important parameter that influences the energy absorption characteristics during crash was the thickness reduction caused by circumferential expansion of the tube during hydroforming. It was found that that the energy absorption decreased as the corner radius decreased, which results because of increased thinning. Sensitivity studies of end feeding parameters, such as end feed level and profile, were carried out to evaluate their impact on the energy absorption of the aluminium tubes.

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

2007-05-01

464

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

SciTech Connect

The motivation to reduce overall vehicle weight within the automotive sector drives the substitution of lightweight materials such as aluminium alloys for structural components. Such a substitution requires a significant amount of development to manufacture structurally parts such that the energy absorption characteristics are not sacrificed in the event of crash. The effects of the manufacturing processes on the crash performance of automotive structural components must be better understood to ensure improved crashworthiness. This paper presents results of an experimental and numerical investigation of the crash response and energy absorption properties of impacted hydroformed aluminium alloy tubes. Crash experiments on hydroformed tubes were performed using a deceleration sled test at the General Motors Technical Center. Results from axial crush testing showed that an important parameter that influences the energy absorption characteristics during crash was the thickness reduction caused by circumferential expansion of the tube during hydroforming. It was found that that the energy absorption decreased as the corner radius decreased, which results because of increased thinning. Sensitivity studies of end feeding parameters, such as end feed level and profile, were carried out to evaluate their impact on the energy absorption of the aluminium tubes.

D'Amours, Guillaume; Rahem, Ahmed [National Research Council Canada, Aluminium Technology Centre, 501 University Blvd. East, Chicoutimi, Quebec, G7H 8C3 (Canada); Mayer, Robert [General Motors Technical Centre, 6250 Chicago Road, Warren, MI (United States); Williams, Bruce; Worswick, Michael [University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1 (Canada)

2007-05-17

465

Speciation study of aluminium in beverages by Competitive Ligand Exchange-Adsorptive Stripping Voltammetry.  

PubMed

Competitive Ligand Exchange-Adsorptive Stripping Voltammetry (CLE-AdSV) was used for determining the speciation of aluminium in commonly consumed beverages (water, tea, infusion, coffee, orange juice, tomato juice, beer and red wine). Aluminium determination involves the adsorption of Al-complexes with the ligand cupferron onto a hanging mercury drop electrode. All samples were studied at pH 6.5 with an accumulation step at -0.60 V (all potential values in the paper are given versus the Ag/AgCl, [KCl]=3 M reference electrode) during 60 s, and a final cupferron concentration of 4 × 10(-4)M. These conditions were used to establish (i) the concentration of electro-labile aluminium, (ii) the range of ligand concentrations and (iii) the conditional stability constants of beverage samples using titration procedures. The results based on Ruzic plots were compared to computer simulation with Visual MINTEQ. This comparison suggests that labile monomeric Al-forms and soluble organic complexes of low molecular weight can be quantified by the CLE-AdSV procedure. Overall the relative uncertainties on the determination of the electro-active Al fraction and the complexing parameters, i.e., concentration and conditional stability constant of natural ligands in the samples, are less than 15%. Thanks to these results, information on Al bioavailability in beverages was collected and discussed. This study also illustrates the value of computer simulations when complex, time-consuming voltammetric techniques are applied. PMID:24720958

Magnier, A; Fekete, V; Van Loco, J; Bolle, F; Elskens, M

2014-05-01

466

Reinforcement with fluoroplastic additives  

SciTech Connect

The use of high molecular weight polytetrafluoroethylene (PTFE) as a reinforcing additive to improve the tear strength of elastomers was studied in silicone rubber by the mid-1950s and in fluoroelastomers by the late-1960s. Although the PTFE is added as a powder, the shear developed during compounding into an elastomer fibrillates the power into a continuous network of nodes and fibers. This network structure effectively reinforces elastomers but it also leads to distortion of finished parts and unacceptably high hardness and modulus of vulcanizates. A new high molecular weight TFE/HFP fluoroplastic micropowder has recently been developed (Teflon MP1500, Du Pont) which forms short fibers, ribbons or platelets when compounded with sufficient shear into elastomers. The controlled structure developed during compounding allows high levels of incorporation of the micropowder into elastomers with uniform dispersion and results in significant improvements in tear strength and abrasion resistance, as well as reduced coefficients of friction.

Morgan, R.A.; Stewart, C.W.; Thomas, E.W.; Stahl, W.M.

1991-05-01

467

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

468

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

469

RGB Additive Color  

NSDL National Science Digital Library

Color is all around us. RGB is the color system that is used when mixing light. The RGB system is what we use in computers, televisions, stage lighting, displays and more. It is also called the additive color system because the colors are combined or added to each other to make the colors that we see. What wavelength goes with a color? Remember that a a nanometer is a unit of length in the metric system equal to one billionth of a meter. NASA What is a wave? NASA Color Why is the sky blue? What is RGB and how and where is it used? RGB World 21st Century Color Theory RGB colors are identified on computers by a color value that ranges for R, G, and B, ...

Mr. Engelman

2010-12-05

470

Ceramics with Different Additives  

NASA Astrophysics Data System (ADS)

Li2CO3, MgCO3, BaCO3, and Bi2O3 dopants were introduced into CaCu3Ti4O12 (CCTO) ceramics in order to improve the dielectric properties. The CCTO ceramics were prepared by conventional solid-state reaction method. The phase structure, microstructure, and dielectric behavior were carefully investigated. The pure structure without any impurity phases can be confirmed by the x-ray diffraction patterns. Scanning Electron Microscopy (SEM) analysis illuminated that the grains of Ca0.90Li0.20Cu3Ti4O12 ceramics were greater than that of pure CCTO. It was important for the properties of the CCTO ceramics to study the additives in complex impedance spectroscopy. It was found that the Ca0.90Li0.20Cu3Ti4O12 ceramics had the higher permittivity (>45000), the lower dielectric loss (<0.025) than those of CCTO at 1 kHz at room temperature and good temperature stability from -30 to 75 °C.

Wang, Juanjuan; Feng, Lajun; Lei, Ali; Zhao, Kang; Yan, Aijun

2014-09-01

471

Hepatic and cerebrospinal fluid accumulation of aluminium and bismuth in volunteers taking short course anti-ulcer therapy.  

PubMed

To investigate the possible absorption and deposition of bismuth or aluminium from agents used in the treatment of peptic ulcers, we have measured levels of bismuth and aluminium in the liver tissue of 15 patients undergoing elective liver biopsy and in the cerebrospinal fluid (CSF) of 15 patients undergoing elective myelography after administration of standard therapeutic doses of tripotassium dicitrato bismuthate (TBS), sucralfate or aluminium hydroxide for 1 month. Aliquots of liver or CSF were separated and levels of both aluminium and bismuth were assayed in each sample by atomic absorption spectrophotometry. The group who received TBS had significantly higher liver bismuth levels than the other two treatment groups, but there was no significant difference in CSF bismuth levels among the three groups. There was no significant difference in either liver or CSF aluminium levels among the three treatment groups. We conclude that tissue accumulation of bismuth may occur after short-course therapy with colloidal bismuth, although there is no evidence of CNS accumulation of bismuth in the present study. PMID:8912126

Gane, E; Sutton, M M; Pybus, J; Hamilton, I

1996-10-01

472

Nucleation of the diamond phase in aluminium-solid solutions  

NASA Technical Reports Server (NTRS)

Precipitation was studied from fcc solid solutions with silicon, germanium, copper and magnesium. Of all these elements only silicon and germanium form diamond cubic (DC) precipitates in fcc Al. Nucleation of the DC structure is enhanced if both types of atom are dissolved in the fcc lattice. This is interpreted as due to atomic size effects in the prenucleation stage. There are two modes of interference of fourth elements with nucleation of the DC phase in Al + Si, Ge. The formation of the DC phase is hardly affected if the atoms (for example, copper) are rejected from the (Si, Ge)-rich clusters. If additional types of atom are attracted by silicon and/or germanium, DC nuclei are replaced by intermetallic compounds (for example Mg2Si).

Hornbogen, E.; Mukhopadhyay, A. K.; Starke, E. A., Jr.

1993-01-01

473

Development of duplex nitrided and closed field unbalanced magnetron sputter ion plated CrTiAlN-based coatings for H13 aluminium extrusion dies  

Microsoft Academic Search

Extruded aluminium alloy is already a ubiquitous engineering material, but there is increasing demand for aluminium-based metal matrix composites (MMCs) with improved stiffness and wear resistance to further extend the material's range of application. The extrusion of MMCs containing significant quantities of hard, second-phase particulates places particular demands on the die, which must obviously maintain its critical mechanical and tribological

K. E. Cooke; S. Yang; C. Selcuk; A. Kennedy; D. G. Teer; D. Beale

2004-01-01

474

Structural study of Al2O3-Na2O-CaO-P2O5 bioactive glasses as a function of aluminium content  

NASA Astrophysics Data System (ADS)

Calcium phosphate based biomaterials are extensively used in the context of tissue engineering: small changes in composition can lead to significant changes in properties allowing their use in a wide range of applications. Samples of composition (Al2O3)x(Na2O)0.11-x(CaO)0.445(P2O5)0.445, where x = 0, 0.03, 0.05, and 0.08, were prepared by melt quenching. The atomic-scale structure has been studied using neutron diffraction and solid state 27Al MAS NMR, and these data have been rationalised with the determined density of the final glass product. With increasing aluminium concentration the density increases initially, but beyond about 3 mol. % Al2O3 the density starts to decrease. Neutron diffraction data show a concomitant change in the aluminium speciation, which is confirmed by 27Al MAS NMR studies. The NMR data reveal that aluminium is present in 4, 5, and 6-fold coordination and that the relative concentrations of these environments change with increasing aluminium concentration. Materials containing aluminium in 6-fold coordination tend to have higher densities than analogous materials with the aluminium found in 4-fold coordination. Thus, the density changes may readily be explained in terms of an increase in the relative concentration of 4-coordinated aluminium at the expense of 6-fold aluminium as the Al2O3 content is increased beyond 3 mol. %.

Smith, J. M.; King, S. P.; Barney, E. R.; Hanna, J. V.; Newport, R. J.; Pickup, D. M.

2013-01-01

475

Investigation of the particle size distribution of the ejected material generated during the single femtosecond laser pulse ablation of aluminium  

NASA Astrophysics Data System (ADS)

Single femtosecond laser pulses are employed to ablate an aluminium target in vacuum, and the particle size distribution of the ablated material deposited on a mica substrate is examined with atomic force microscopy (AFM). The recorded AFM images show that these particles have a mean radius of several tens of nanometres. It is also determined that the mean radius of these deposited nanoparticles increases when the laser fluence at the aluminium target increases from 0.44 J/cm2 to 0.63 J/cm2. The mechanism of the laser-induced nanoparticle generation is thought to be photomechanical tensile stress relaxation. Raman spectroscopy measurements confirm that the nanoparticles thus produced have the same structure as the bulk aluminium.

Wu, Han; Zhang, Nan; Zhu, Xiaonong

2014-10-01

476

Acoustic neuroma: potential risk factors and audiometric surveillance in the aluminium industry  

PubMed Central

Objectives To look for an association between acoustic neuroma (AN) and participation in a hearing conservation programme (HCP) and also for an association between AN and possible occupational risk factors in the aluminium industry. Methods We conducted a case–control analysis of a population of US aluminium production workers in 8 smelters and 43 other plants. Using insurance claims data, 97 cases of AN were identified between 1996 and 2009. Each was matched with four controls. Covariates included participation in a HCP, working in an aluminium smelter, working in an electrical job and hearing loss. Results In the bivariate analyses, covariates associated with AN were participation in the HCP (OR=1.72; 95% CI 1.09 to 2.69) and smelter work (OR=1.88; 95% CI 1.06 to 3.36). Electrical work was not significant (OR=1.60; 95% CI 0.65 to 3.94). Owing to high participation in the HCP in smelters, multivariate subanalyses were required. In the multivariate analyses, participation in the HCP was the only statistically significant risk factor for AN. In the multivariate analysis restricted to employees not working in a smelter, the OR was 1.81 (95% CI 1.04 to 3.17). Hearing loss, an indirect measure of in-ear noise dose, was not predictive of AN. Conclusions Our results suggest the incidental detection of previously undiagnosed tumours in workers who participated in the company-sponsored HCP. The increased medical surveillance among this population of workers most likely introduced detection bias, leading to the identification of AN cases that would have otherwise remained undetected. PMID:25015928

Taiwo, Oyebode; Galusha, Deron; Tessier-Sherman, Baylah; Kirsche, Sharon; Cantley, Linda; Slade, Martin D; Cullen, Mark R; Donoghue, A Michael

2014-01-01

477

Acute oral toxicity and biodistribution study of zinc-aluminium-levodopa nanocomposite.  

PubMed

Layered double hydroxide (LDH) is an inorganic-organic nano-layered material that harbours drug between its two-layered sheets, forming a sandwich-like structure. It is attracting a great deal of attention as an alternative drug delivery (nanodelivery) system in the field of pharmacology due to their relative low toxic potential. The production of these nanodelivery systems, aimed at improving human health through decrease toxicity, targeted delivery of the active compound to areas of interest with sustained release ability. In this study, we administered zinc-aluminium-LDH-levodopa nanocomposite (ZAL) and zinc-aluminium nanocomposite (ZA) to Sprague Dawley rats to evaluate for acute oral toxicity following OECD guidelines. The oral administration of ZAL and ZA at a limit dose of 2,000 mg/kg produced neither mortality nor acute toxic signs throughout 14 days of the observation. The percentage of body weight gain of the animals showed no significant difference between control and treatment groups. Animal from the two treated groups gained weight continuously over the study period, which was shown to be significantly higher than the weight at the beginning of the study (P?aluminium nanocomposite intercalated with and the un-intercalated were safe when administered orally in animal models for short periods of time. It also highlighted the potential distribution ability of Tween-80 coated nanocomposite after oral administration. PMID:25852400

Kura, Aminu Umar; Saifullah, Bullo; Cheah, Pike-See; Hussein, Mohd Zobir; Azmi, Norazrina; Fakurazi, Sharida

2015-01-01

478

Acute oral toxicity and biodistribution study of zinc-aluminium-levodopa nanocomposite  

NASA Astrophysics Data System (ADS)

Layered double hydroxide (LDH) is an inorganic-organic nano-layered material that harbours drug between its two-layered sheets, forming a sandwich-like structure. It is attracting a great deal of attention as an alternative drug delivery (nanodelivery) system in the field of pharmacology due to their relative low toxic potential. The production of these nanodelivery systems, aimed at improving human health through decrease toxicity, targeted delivery of the active compound to areas of interest with sustained release ability. In this study, we administered zinc-aluminium-LDH-levodopa nanocomposite (ZAL) and zinc-aluminium nanocomposite (ZA) to Sprague Dawley rats to evaluate for acute oral toxicity following OECD guidelines. The oral administration of ZAL and ZA at a limit dose of 2,000 mg/kg produced neither mortality nor acute toxic signs throughout 14 days of the observation. The percentage of body weight gain of the animals showed no significant difference between control and treatment groups. Animal from the two treated groups gained weight continuously over the study period, which was shown to be significantly higher than the weight at the beginning of the study ( P < 0.05). Biochemical analysis of animal serum showed no significant difference between rats treated with ZAL, ZA and controls. There was no gross lesion or histopathological changes observed in vital organs of the rats. The results suggested that ZAL and ZA at 2,000 mg/kg body weight in rats do not induce acute toxicity in the animals. Elemental analysis of tissues of treated animals demonstrated the wider distribution of the nanocomposite including the brain. In summary, findings of acute toxicity tests in this study suggest that zinc-aluminium nanocomposite intercalated with and the un-intercalated were safe when administered orally in animal models for short periods of time. It also highlighted the potential distribution ability of Tween-80 coated nanocomposite after oral administration.

Kura, Aminu Umar; Saifullah, Bullo; Cheah, Pike-See; Hussein, Mohd Zobir; Azmi, Norazrina; Fakurazi, Sharida