Concentrations of polycyclic aromatic hydrocarbons in resuspendable fraction of settled bus dust and its implications for human exposure

International Nuclear Information System (INIS)

Gao, Peng; Liu, Sa; Feng, Yujie; Lin, Nan; Lu, Binyu; Zhang, Zhaohan; Cui, Fuyi; Xing, Baoshan; Hammond, S. Katharine

2015-01-01

This preliminary study measured Polycyclic Aromatic Hydrocarbons (PAHs) concentrations in the resuspendable fraction of settled dust on 39 bus lines, to evaluate the impact of engine type (gasoline and compressed natural gas) on exposure for commuters and drivers. Benzo(b)fluoranthene(BbF) was the predominant PAH in resuspendable fraction of settled bus dust. The concentration of total PAHs was 92.90 ± 116.00 μg/g (range: 0.57–410) in gasoline buses and 3.97 ± 1.81 (range: 2.01–9.47) in compressed natural gas (CNG) buses. Based on Benzo[a]pyrene (BaP) equivalent concentrations for the sum of 16 PAHs, the average daily dose (ADD) via dust ingestion and dermal contact was calculated. The ADD of PAHs was higher for commuters and drivers in gasoline-powered buses than in buses using CNG buses. For both short and long duration journeys, young commuters were exposed to higher levels of PAHs via dust ingestion and dermal contact than adult commuters. - Highlights: • Resuspendable fraction of settled dust from microenvironment of buses in Harbin monitored for PAHs exposure assessment. • Higher levels of PAHs pollutants at gasoline-powered buses than at compressed natural gas-powered buses. • Non-occupational and occupational exposures in the microenvironment of buses are assessed. - Occupational and non-occupational exposure to PAHs from the microenvironment of bus

Study of the presence of fluorine in the recycled fractions during carbothermal treatment of EAF dust.

Science.gov (United States)

Menad, N; Ayala, J N; Garcia-Carcedo, Fernando; Ruiz-Ayúcar, E; Hernández, A

2003-01-01

Carbothermal treatment tests of electric arc furnace dusts (EAFD) using the Waelz kiln process were carried out in pilot-scale for the production of zinc oxide. The association of halides in the EAFD, and the recycled products, such as zinc oxide fumes and high-grade iron contents fractions were examined by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM) analysis. XRD reveals the presence of chlorine and fluorine in the dusts in the form of KCl, NaCl and CaF2. An ultra-pure fraction of zinc was obtained after the Double Leaching Waelz Oxide (DLWO) process was performed on the zinc oxide fumes. The halide contents were reduced to approximately 100 ppm Cl and 700 ppm F. The rest of these elements are in the form of CaF2. About 65% F is volatilised as lead and zinc fluorides, 15% is expected in the magnetic fractions and 20% in non-magnetic fractions as CaF2 and MnF2, respectively.

Chemical mimicking of bio-assisted aluminium extraction by Aspergillus niger's exometabolites.

Science.gov (United States)

Boriová, Katarína; Urík, Martin; Bujdoš, Marek; Pifková, Ivana; Matúš, Peter

2016-11-01

Presence of microorganisms in soils strongly affects mobility of metals. This fact is often excluded when mobile metal fraction in soil is studied using extraction procedures. Thus, the first objective of this paper was to evaluate strain Aspergillus niger's exometabolites contribution on aluminium mobilization. Fungal exudates collected in various time intervals during cultivation were analyzed and used for two-step bio-assisted extraction of alumina and gibbsite. Oxalic, citric and gluconic acids were identified in collected culture media with concentrations up to 68.4, 2.0 and 16.5 mmol L -1 , respectively. These exometabolites proved to be the most efficient agents in mobile aluminium fraction extraction with aluminium extraction efficiency reaching almost 2.2%. However, fungal cultivation is time demanding process. Therefore, the second objective was to simplify acquisition of equally efficient extracting agent by chemically mimicking composition of main organic acid components of fungal exudates. This was successfully achieved with organic acids mixture prepared according to medium composition collected on the 12th day of Aspergillus niger cultivation. This mixture extracted similar amounts of aluminium from alumina compared to culture medium. The aluminium extraction efficiency from gibbsite by organic acids mixture was lesser than 0.09% which is most likely because of more rigid mineral structure of gibbsite compared to alumina. The prepared organic acid mixture was then successfully applied for aluminium extraction from soil samples and compared to standard single step extraction techniques. This showed there is at least 2.9 times higher content of mobile aluminium fraction in soils than it was previously considered, if contribution of microbial metabolites is considered in extraction procedures. Thus, our contribution highlights the significance of fungal metabolites in aluminium extraction from environmental samples, but it also simplifies the

Concentrations of polycyclic aromatic hydrocarbons in resuspendable fraction of settled bus dust and its implications for human exposure.

Science.gov (United States)

Gao, Peng; Liu, Sa; Feng, Yujie; Lin, Nan; Lu, Binyu; Zhang, Zhaohan; Cui, Fuyi; Xing, Baoshan; Hammond, S Katharine

2015-03-01

This preliminary study measured Polycyclic Aromatic Hydrocarbons (PAHs) concentrations in the resuspendable fraction of settled dust on 39 bus lines, to evaluate the impact of engine type (gasoline and compressed natural gas) on exposure for commuters and drivers. Benzo(b)fluoranthene(BbF) was the predominant PAH in resuspendable fraction of settled bus dust. The concentration of total PAHs was 92.90 ± 116.00 μg/g (range: 0.57-410) in gasoline buses and 3.97 ± 1.81 (range: 2.01-9.47) in compressed natural gas (CNG) buses. Based on Benzo[a]pyrene (BaP) equivalent concentrations for the sum of 16 PAHs, the average daily dose (ADD) via dust ingestion and dermal contact was calculated. The ADD of PAHs was higher for commuters and drivers in gasoline-powered buses than in buses using CNG buses. For both short and long duration journeys, young commuters were exposed to higher levels of PAHs via dust ingestion and dermal contact than adult commuters. Copyright © 2014 Elsevier Ltd. All rights reserved.

Toxicity of dissolved and precipitated aluminium to marine diatoms.

Science.gov (United States)

Gillmore, Megan L; Golding, Lisa A; Angel, Brad M; Adams, Merrin S; Jolley, Dianne F

2016-05-01

Localised aluminium contamination can lead to high concentrations in coastal waters, which have the potential for adverse effects on aquatic organisms. This research investigated the toxicity of 72-h exposures of aluminium to three marine diatoms (Ceratoneis closterium (formerly Nitzschia closterium), Minutocellus polymorphus and Phaeodactylum tricornutum) by measuring population growth rate inhibition and cell membrane damage (SYTOX Green) as endpoints. Toxicity was correlated to the time-averaged concentrations of different aluminium size-fractions, operationally defined as aluminium exposure varied between diatom species. C. closterium was the most sensitive species (10% inhibition of growth rate (72-h IC10) of 80 (55-100)μg Al/L (95% confidence limits)) while M. polymorphus (540 (460-600)μg Al/L) and P. tricornutum (2100 (2000-2200)μg Al/L) were less sensitive (based on measured total aluminium). Dissolved aluminium was the primary contributor to toxicity in C. closterium, while a combination of dissolved and precipitated aluminium forms contributed to toxicity in M. polymorphus. In contrast, aluminium toxicity to the most tolerant diatom P. tricornutum was due predominantly to precipitated aluminium. Preliminary investigations revealed the sensitivity of C. closterium and M. polymorphus to aluminium was influenced by initial cell density with aluminium toxicity significantly (paluminium toxicity to diatoms do not involve compromising the plasma membrane. These results indicate that marine diatoms have a broad range in sensitivity to aluminium with toxic mechanisms related to both dissolved and precipitated aluminium. Copyright © 2016 Elsevier B.V. All rights reserved.

Investigation of methods for physical characteristics of atmospheric aerosols and ground dust fractions on radioactive contaminated areas

International Nuclear Information System (INIS)

Artem'ev, O.I.; Osintsev, A.Yu.; Gaziev, Ya.I.; Gordeev, S.K.

2005-01-01

The paper presents data about current situation and trends to develop investigation methods for physical characteristics of atmospheric aerosols and ground dust fractions that are observed on the former Semipalatinsk Test Site area and adjacent regions. It was considered one of the options for comprehensive collection of radioactive aerosols as fallout within control area of atmospheric contamination and underlying surface with aerosol products of the man-caused dusting on the former STS area to determine rates of 'dry' deposition and ground-based activity concentration contained in these products of radionuclides at different distances from place of dusting. (author)

Aluminium/iron reinforced polyfurfuryl alcohol resin as advanced biocomposites

Directory of Open Access Journals (Sweden)

Rakesh Kumar

2016-07-01

Full Text Available Aluminium and iron are widely used in construction sectors for the preparation of advanced composites with epoxy resins as matrices. In recent times, there are several reports on the polymerization of polyfufuryl alcohol (PFA a thermoset bioresins from furfuryl alcohol (FA. FA is obtained from waste of sugarcane bagasse. In this work, first the possibility of curing PFA from FA in the presence of aluminium or iron has been explored. Absorbance results from colorimeter/spectrophotometerindicated that the curing of FA to PFA in presence of aluminium started easily while in presence of iron the curing of FA to PFA could not start. Based on the above results, aluminium wire reinforced composites were successfully prepared with three different weight fractions (0.13, 0.09 and 0.07 of aluminium wire. The mechanical properties of these composites were determined theoretically and reported.

The actual prevention of fibrogenic effect of mineral dust

Directory of Open Access Journals (Sweden)

Bobro Milan

2000-09-01

Full Text Available The dustiness occurs in the mining work environment during the process of disintegration of rocks by drilling, explosion and dislocation. The dust contains minerals forming the massif, under Slovak mining conditions, it was usually quartz and some other minerals. They usually accompanied utility minerals. The characteristic mining aerosol is created during disintegration process. It was inhaled by miners and due to the most dangerous fibrogenic mineral – quartz – it caused that employees suffered from the so far incurable industrial disease. From that reason a long-term research of reaction qualities of quartz dust was carried out and the possibility to decrease its fibrogenic properties was researched. The prevention vested in the elimination of these properties on the surface of quartz grain or other silicate before entering, i.e. being inhaled by lungs, using water soluble aluminium hydroxide compound. This water was used for flushing in drilling process and to decrease dustiness by spraying it directly in the mining workplace. The aluminium hydroxide agent reacted with mineral dust directly in aerosol before being inhaled. The principle vested in the reaction of one mole of agent with two moles of surface structures of quartz particle forming a thermostatic layer of a new mineral type, in this case aluminium silicate of kaolinite. The required concentration of aluminium hydroxide compound solution for pure quartz dust was determined by experimental works and calculation with a required reserve or even slight excess of agent. If the fibrogenity of quartz not influenced in this manner was considered as 100%, its cytostatic and consequently fibrogenic effect would be decreased by the influence of this agent minimally by 60%. The method has been tested directly in mines, but due to recession of mining industry, it was not introduced in practice, however, it is currently getting a certain significance in tunnelling of transport tunnels in

Assessment on the occupational exposure of urban public bus drivers to bioaccessible trace metals through resuspended fraction of settled bus dust

Energy Technology Data Exchange (ETDEWEB)

Gao, Peng [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No. 73 Huanghe Road, Nangang District, Harbin 150090 (China); Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003 (United States); Liu, Sa [Environmental Health Sciences Division, School of Public Health, University of California, Berkeley, CA, 94720-7360 (United States); Ye, Wenyuan [Department of Chemical Engineering, KU Leuven, Willem de Croylaan 46, B-3001 Heverlee (Belgium); Lin, Nan; Meng, Ping [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No. 73 Huanghe Road, Nangang District, Harbin 150090 (China); Feng, Yujie, E-mail: yujief@hit.edu.cn [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No. 73 Huanghe Road, Nangang District, Harbin 150090 (China); Zhang, Zhaohan; Cui, Fuyi; Lu, Binyu [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No. 73 Huanghe Road, Nangang District, Harbin 150090 (China); Xing, Baoshan [Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003 (United States)

2015-03-01

Limited information is available on the bioaccessible fraction of trace metals in the resuspended fraction of settled bus dust in order to estimate bus drivers ' occupational exposure. In this study, 45 resuspended fraction of settled dust samples were collected from gasoline and compressed natural gas (CNG) powered buses and analyzed for trace metals and their fraction concentrations using a three-step sequential extraction procedure. Experimental results showed that zinc (Zn) had the greatest bioaccessible fraction, recorded as an average of 608.53 mg/kg, followed in order of decreasing concentration by 129.80 mg/kg lead (Pb), 56.77 mg/kg copper (Cu), 34.03 mg/kg chromium (Cr), 22.05 mg/kg nickel (Ni), 13.17 mg/kg arsenic (As) and 2.77 mg/kg cadmium (Cd). Among the three settled bus dust exposure pathways, ingestion was the main route. Total exposure hazard index (HIt) for non-carcinogenic effect trace metals was lower than the safety level of 1. The incremental lifetime cancer risk (ILCR) for drivers was estimated for trace metal exposure. Pb and Ni presented relatively high potential risks in the non-carcinogenic and potentially carcinogenic health assessment for all drivers. ILCR was in the range of 1.84E − 05 to 7.37E − 05 and 1.74E − 05 to 6.95E − 05 for gasoline and CNG buses, respectively. - Highlights: • As, Cd and Ni had relatively higher bioaccessibility and mobility in the resuspended fraction of settled bus dust. • Bioaccessible metal concentrations were higher in gasoline-fueled buses than those in CNG-fueled buses. • The carcinogenic risk probabilities to drivers were around the acceptable level.

The heavy metal partition in size-fractions of the fine particles in agricultural soils contaminated by waste water and smelter dust

Energy Technology Data Exchange (ETDEWEB)

Zhang, Haibo, E-mail: hbzhang@yic.ac.cn [Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China); Luo, Yongming, E-mail: ymluo@yic.ac.cn [Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China); Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Makino, Tomoyuki [National Institute for Agro-Environmental Sciences, Tsukuba 3058604 (Japan); Wu, Longhua [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Nanzyo, Masami [Tohoku University, Sendai 9808576 (Japan)

2013-03-15

Highlights: ► A continuous flow ultra-centrifugation method has been developed to obtain fine particles from polluted agricultural soil. ► Pollution source affected the heavy metal fractionation in size-fractions by changing soil particle properties. ► The iron oxides affected the distribution of lead species more than other metals in the smelter dust polluted particles. -- Abstract: The partitioning of pollutant in the size-fractions of fine particles is particularly important to its migration and bioavailability in soil environment. However, the impact of pollution sources on the partitioning was seldom addressed in the previous studies. In this study, the method of continuous flow ultra-centrifugation was developed to separate three size fractions (<1 μm, <0.6 μm and <0.2 μm) of the submicron particles from the soil polluted by wastewater and smelter dust respectively. The mineralogy and physicochemical properties of each size-fraction were characterized by X-ray diffraction, transmission electron microscope etc. Total content of the polluted metals and their chemical speciation were measured. A higher enrichment factor of the metals in the fractions of <1 μm or less were observed in the soil contaminated by wastewater than by smelter dust. The organic substance in the wastewater and calcite from lime application were assumed to play an important role in the metal accumulation in the fine particles of the wastewater polluted soil. While the metal accumulation in the fine particles of the smelter dust polluted soil is mainly associated with Mn oxides. Cadmium speciation in both soils is dominated by dilute acid soluble form and lead speciation in the smelter dust polluted soil is dominated by reducible form in all particles. This implied that the polluted soils might be a high risk to human health and ecosystem due to the high bioaccessblity of the metals as well as the mobility of the fine particles in soil.

The heavy metal partition in size-fractions of the fine particles in agricultural soils contaminated by waste water and smelter dust

International Nuclear Information System (INIS)

Zhang, Haibo; Luo, Yongming; Makino, Tomoyuki; Wu, Longhua; Nanzyo, Masami

2013-01-01

Highlights: ► A continuous flow ultra-centrifugation method has been developed to obtain fine particles from polluted agricultural soil. ► Pollution source affected the heavy metal fractionation in size-fractions by changing soil particle properties. ► The iron oxides affected the distribution of lead species more than other metals in the smelter dust polluted particles. -- Abstract: The partitioning of pollutant in the size-fractions of fine particles is particularly important to its migration and bioavailability in soil environment. However, the impact of pollution sources on the partitioning was seldom addressed in the previous studies. In this study, the method of continuous flow ultra-centrifugation was developed to separate three size fractions (<1 μm, <0.6 μm and <0.2 μm) of the submicron particles from the soil polluted by wastewater and smelter dust respectively. The mineralogy and physicochemical properties of each size-fraction were characterized by X-ray diffraction, transmission electron microscope etc. Total content of the polluted metals and their chemical speciation were measured. A higher enrichment factor of the metals in the fractions of <1 μm or less were observed in the soil contaminated by wastewater than by smelter dust. The organic substance in the wastewater and calcite from lime application were assumed to play an important role in the metal accumulation in the fine particles of the wastewater polluted soil. While the metal accumulation in the fine particles of the smelter dust polluted soil is mainly associated with Mn oxides. Cadmium speciation in both soils is dominated by dilute acid soluble form and lead speciation in the smelter dust polluted soil is dominated by reducible form in all particles. This implied that the polluted soils might be a high risk to human health and ecosystem due to the high bioaccessblity of the metals as well as the mobility of the fine particles in soil

Aluminium production

International Nuclear Information System (INIS)

Winter, B.; Ayers, J.; Sammer, G.

2001-01-01

Aluminium is the most important non-ferrous metal by quantity. Aluminium is produced by electrolysis of aluminium oxide (also known as alumina). Alumina is produced by refining bauxite. The quantity of primary and secondary aluminium production in ECE-countries between 1992 and 1998 is shown. The European aluminium industry employs approximately 200 000 employees. The annual aluminium production in the European Union was 3.58 million tonnes in 1994, of which 44 % was secondary aluminium. In 1996 3.96 million tonnes of aluminium were produced in the EU, of which 44 % was secondary aluminium. (author)

Direct-reading inhalable dust monitoring--an assessment of current measurement methods.

Science.gov (United States)

Thorpe, Andrew; Walsh, Peter T

2013-08-01

Direct-reading dust monitors designed specifically to measure the inhalable fraction of airborne dust are not widely available. Current practice therefore often involves comparing the response of photometer-type dust monitors with the concentration measured with a reference gravimetric inhalable sampler, which is used to adjust the dust monitor measurement. However, changes in airborne particle size can result in significant errors in the estimation of inhalable concentration by this method. The main aim of this study was to assess how these dust monitors behave when challenged with airborne dust containing particles in the inhalable size range and also to investigate alternative dust monitors whose response might not be as prone to variations in particle size or that could be adapted to measure inhalable dust concentration. Several photometer-type dust monitors and a Respicon TM, tapered element oscillating microbalance (TEOM) personal dust monitor (PDM) 3600, TEOM 1400, and Dustrak DRX were assessed for the measurement of airborne inhalable dust during laboratory and field trials. The PDM was modified to allow it to sample and measure larger particles in the inhalable size range. During the laboratory tests, the dust monitors and reference gravimetric samplers were challenged inside a large dust tunnel with aerosols of industrial dusts known to present an inhalable hazard and aluminium oxide powders with a range of discrete particle sizes. A constant concentration of each dust type was generated and peak concentrations of larger particles were periodically introduced to investigate the effects of sudden changes in particle size on monitor calibration. The PDM, Respicon, and DataRam photometer were also assessed during field trials at a bakery, joinery, and a grain mill. Laboratory results showed that the Respicon, modified PDM, and TEOM 1400 observed good linearity for all types of dust when compared with measurements made with a reference IOM sampler; the

Air pollution assessment based on elemental concentration of leaves tissue and foliage dust along an urbanization gradient in Vienna.

Science.gov (United States)

Simon, Edina; Braun, Mihály; Vidic, Andreas; Bogyó, Dávid; Fábián, István; Tóthmérész, Béla

2011-05-01

Foliage dust contains heavy metal that may have harmful effects on human health. The elemental contents of tree leaves and foliage dust are especially useful to assess air environmental pollution. We studied the elemental concentrations in foliage dust and leaves of Acer pseudoplatanus along an urbanization gradient in Vienna, Austria. Samples were collected from urban, suburban and rural areas. We analysed 19 elements in both kind of samples: aluminium, barium, calcium, copper, iron, potassium, magnesium, sodium, phosphor, sulphur, strontium and zinc. We found that the elemental concentrations of foliage dust were significantly higher in the urban area than in the rural area for aluminium, barium, iron, lead, phosphor and selenium. Elemental concentrations of leaves were significantly higher in urban than in rural area for manganese and strontium. Urbanization changed significantly the elemental concentrations of foliage dust and leaves and the applied method can be useful for monitoring the environmental load. Copyright © 2011 Elsevier Ltd. All rights reserved.

Aluminium bridges, aluminium bridge decks

NARCIS (Netherlands)

Soetens, F.; Straalen, IJ.J. van

2003-01-01

Applications of aluminium have grown considerably in building and civil engineering the last decade. In building and civil engineering the increase of aluminium applications is due to various aspects like light weight, durability and maintenance, use of extrusions, and esthetics. The paper starts

Volatilisation and oxidation of aluminium scraps fed into incineration furnaces

International Nuclear Information System (INIS)

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

2012-01-01

Highlights: ► Aluminium packaging partitioning in MSW incineration residues is evaluated. ► The amount of aluminium packaging recoverable from the bottom ashes is evaluated. ► Aluminium packaging oxidation rate in the residues of MSW incineration is evaluated. ► 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.

Linear Alkylbenzenesulfonates in indoor Floor Dust

DEFF Research Database (Denmark)

Madsen, Jørgen Øgaard; Wolkoff, Peder; Madsen, Jørgen Øgaard

1999-01-01

The amount of Linear Alkylbenzenesulfonates (LAS) in the particle fraction of floor dust sampled from 7 selected public buildings varied between 34 and 1500 microgram per gram dust, while the contents of the fibre fractions generally were higher with up to 3500 microgram LAS/g dust. The use...... of a cleaning agent with LAS resulted in an increase of the amount of LAS in the floor dust after floor wash relative to just before floor wash. However, the most important source of LAS in the indoor floor dust appears to be residues of detergent in clothing. Thus, a newly washed shirt contained 2960 microgram...

Environment pollution with aluminium around a coalburning electric power plant

International Nuclear Information System (INIS)

Hermann, J.

1997-01-01

The experiments were carried out from November 1991 till November 1993 on the area surrounding an electric power plant within the circle of 20 km diameter and five geographical directions (N, S, SE, E, W). The results presented in this paper have indicated the threats caused by emissions of the power plant ashes and dusts. Mean aluminium content in soil has been multiply surpassed on the area studied. This must have as impact on fauna and flora. The distribution and intensity of pollution is determined first of all by the distance from the emitters and direction of prevailing winds. A part of aluminium contained in water soluble compounds can be distributed on large areas, what adds a lot to the threat to animals. That is why high chimneys do not solve the problem of pollution around big industrial plants. (author)

Exposure to dust and its particle size distribution in shoe manufacture and repair workplaces measured with GRIMM laser dust monitor.

Science.gov (United States)

Stroszejn-Mrowca, Grazyna; Szadkowska-Stańczyk, Irena

2003-01-01

Owing to a diversified technological process and a great variety of products and materials used in shoe manufacture, workers may be exposed to dusts that contain different chemicals and particles of various shapes and sizes. The aim of this study was to assess the dust exposure, taking account of concentration of particular size fractions according to the European Standard Norm, and to analyze particle size distribution in inhalable dust at selected workplaces in a modern shoe manufacture plant and in a small shoe repair workshop in comparison with other industrial branches. In these two workplaces, the concentrations of dust, representing the inhalable, thoracic, and respirable fractions, were measured with the GRIMM 1.105 laser dust monitor. The particle size distribution in inhaled dust in the most characteristic workposts was analyzed. In the shoe manufacture plant, the concentrations ranged from 124 microg/m3 (leather cutting out) to 724 microg/m3 (scouring and milling of soles); concentrations of the thoracic and respirable fractions in the same workposts ranged from 74 microg/m3 to 412 microg/m3 and from 24 microg/m3 to 120 microg/m3, respectively. In the shoe repair workshop, the recorded concentrations were higher: the values ranged from 521 microg/m3 (gluing of shoes and soles, zipper exchange and heel abrasion) to 916 microg/m3 (uppers sewing and heel scouring) for the inhaled fraction; from 335 microg/m3 to 499 microg/m3 for the thoracic fraction; and from 88 microg/m3 to 120 microg/m3 for the respirable fraction. The mass median aerodynamic diameters of inhalable dust particles fell within the limits of 6.2-25.0 mm. Dust with the smallest particles (MMAD = 6.2 mm) was observed in shoe brushing and polishing, and with the largest particles (MMAD = 25.0 mm) in uppers sewing. The modern process of shoe manufacture is characterized by very low concentrations of inhalable dust and its fractions, they are considerably lower than occupational exposure limits

Volatilisation and oxidation of aluminium scraps fed into incineration furnaces

Energy Technology Data Exchange (ETDEWEB)

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

2012-12-15

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

Alloys of uranium and aluminium with low aluminium content; Alliages uranium-aluminium a faible teneur en aluminium

Energy Technology Data Exchange (ETDEWEB)

Cabane, G; Englander, M; Lehmann, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1955-07-01

Uranium, as obtained after spinning in phase {gamma}, presents an heterogeneous structure with large size grains. The anisotropic structure of the metal leads to an important buckling and surface distortion of the fuel slug which is incompatible with its tubular cladding for nuclear fuel uses. Different treatments have been made to obtain an isotropic structure presenting high thermal stability (laminating, hammering and spinning in phase {alpha}) without success. Alloys of uranium and aluminium with low aluminium content present important advantage in respect of non allied uranium. The introduction of aluminium in the form of intermetallic compound (UAl{sub 2}) gives a better resistance to thermal fatigue. Alloys obtained from raw casting present an improved buckling and surface distortion in respect of pure uranium. This improvement is obtained with uranium containing between 0,15 and 0,5 % of aluminium. An even more improvement in thermal stability is obtained by thermal treatments of these alloys. These new characteristics are explained by the fine dispersion of the UAl{sub 2} particles in uranium. The results after treatments obtained from an alloy slug containing 0,4 % of aluminium show no buckling or surface distortion and no elongation. (M.P.)

Computer modelling of age hardening for cast aluminium alloys

International Nuclear Information System (INIS)

Wu, Linda; Ferguson, W George

2009-01-01

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

Rows of Dislocation Loops in Aluminium Irradiated by Aluminium Ions

DEFF Research Database (Denmark)

Henriksen, L.; Johansen, A.; Koch, J.

1967-01-01

Single-crystal aluminium specimens, irradiated with 50-keV aluminium ions, contain dislocation loops that are arranged in regular rows along <110 > directions. ©1967 The American Institute of Physics......Single-crystal aluminium specimens, irradiated with 50-keV aluminium ions, contain dislocation loops that are arranged in regular rows along directions. ©1967 The American Institute of Physics...

A reliability based stress-life evaluation of aluminium-graphite particulate composites

International Nuclear Information System (INIS)

Achutha, M.V.; Sridhara, B.K.; Abdul Budan, D.

2008-01-01

Fatigue tests were conducted on sand cast aluminium-graphite composite specimens on Rotating Beam Fatigue Testing Machine with three different stress levels. Aluminium-graphite (LM 25-5% graphite) composite was processed by closed mould sand casting method. Three-stress level fatigue test program was planned for carrying out fatigue experiments. Three different stress levels selected for fatigue experiments were a fraction of ultimate tensile strength. Statistical design of fatigue experiments was carried out to determine the sample size at each stress level. Experimental results are presented in the form of stress-life (S-N) curves and reliability-stress-life (R-S-N) curves, which are helpful for designers. The S-N curve of the aluminium-graphite composite was compared with its matrix alloy LM 25. Comparison revealed that the fatigue behaviour of the aluminium-graphite composite is superior to that of the matrix alloy

Efficacy and safety of Erbium-doped Yttrium Aluminium Garnet fractional resurfacing laser for treatment of facial acne scars

Directory of Open Access Journals (Sweden)

Balakrishnan Nirmal

2013-01-01

Full Text Available Background: Treatment of acne scars with ablative fractional laser resurfacing has given good improvement. But, data on Indian skin are limited. A study comparing qualitative, quantitative, and subjective assessments is also lacking. Aim: Our aim was to assess the improvement of facial acne scars with Erbium-doped Yttrium Aluminium Garnet (Er:YAG 2940 nm fractional laser resurfacing and its adverse effects in 25 patients at a tertiary care teaching hospital. Methods: All 25 patients received four treatment sessions with Er:YAG fractional laser at 1-month interval. The laser parameters were kept constant for each of the four sittings in all patients. Qualitative and quantitative assessments were done using Goodman and Barron grading. Subjective assessment in percentage of improvement was also documented 1 month after each session. Photographs were taken before each treatment session and 1 month after the final session. Two unbiased dermatologists performed independent clinical assessments by comparing the photographs. The kappa statistics was used to monitor the agreement between the dermatologists and patients. Results: Most patients (96% showed atleast fair improvement. Rolling and superficial box scars showed higher significant improvement when compared with ice pick and deep box scars. Patient′s satisfaction of improvement was higher when compared to physician′s observations. No serious adverse effects were noted with exacerbation of acne lesions forming the majority. Conclusion: Ablative fractional photothermolysis is both effective and safe treatment for atrophic acne scars in Indian skin.Precise evaluation of acne scar treatment can be done by taking consistent digital photographs.

Lattice site occupation of insoluble impurity atoms in aluminium after implantation and irradiation

International Nuclear Information System (INIS)

Kloska, M.K.

1987-03-01

Several elements, whose atoms are oversized and insoluble in aluminium, were implanted in aluminium single crystals at different temperatures. The substitutional fraction and the lattice site location were determined using the ion-channeling technique. The substitutional fractions obtained by in situ analyses are strongly dependent on the implantation temperature. At implantation and analysis temperatures below the temperature of stage III the substitutional fraction is significant larger than at temperatures above. With increasing heat of solution the substitutional fraction decreases for all implantation temperatures. The nonsubstitutional component consists of impurity atom-vacancy complexes. These complexes are formed in the cooling phase of the cascade. At temperatures above the temperature of stage III additional free mobile vacancies were captured by the impurity atoms. The capture radius is correlated with the heat of solution and the size mismatch energy. The results constitute for the first time an experimental confirmation of molecular dynamics calculations of cascade evolution. (orig./BHO)

Effect of trapped electron on the dust ion acoustic waves in dusty plasma using time fractional modified Korteweg-de Vries equation

International Nuclear Information System (INIS)

Nazari-Golshan, A.; Nourazar, S. S.

2013-01-01

The time fractional modified Korteweg-de Vries (TFMKdV) equation is solved to study the nonlinear propagation of small but finite amplitude dust ion-acoustic (DIA) solitary waves in un-magnetized dusty plasma with trapped electrons. The plasma is composed of a cold ion fluid, stationary dust grains, and hot electrons obeying a trapped electron distribution. The TFMKdV equation is derived by using the semi-inverse and Agrawal's methods and then solved by the Laplace Adomian decomposition method. Our results show that the amplitude of the DIA solitary waves increases with the increase of time fractional order β, the wave velocity v 0 , and the population of the background free electrons λ. However, it is vice-versa for the deviation from isothermality parameter b, which is in agreement with the result obtained previously

Investigation of aluminium-rich alloy system of aluminium-strontium-silicium

International Nuclear Information System (INIS)

Ganiev, I.N.; Vakhobov, A.B.; Dzhuraev, T.D.; Alidzhanov, F.N.

1976-01-01

An area of the solid solution based on aluminium was studied, and the surface was plotted of the liquidus adjoining the apex of the aluminium corner of the strontium-aluminium-silicon system. The investigation was carried out by microstructure and differential thermal analyses and by the measurement of the microhardness of the component phases. A combined solubility of silicon and strontium in aluminium was studied along three radial sections at Sr-to-Si ratios of 1/2, 1/1 and 2/1. The relationships of ''composition vs. Microhardness'', obtained in these sections, made it possible to define the boundaries of the phase regions in the aluminium corner of the strontium-aluminium-silicon system at 500 deg C. The greatest solubility is that along the Al-SrAl 2 Si 2 section at a Sr/Si ratio of 1/2. A further increase in the content of strontium brings about a drop in the solubility of silicon in solid aluminium. The projection of the liquidus surface of the strontium-aluminium-silicon system, rich in aluminium, includes four surfaces of primary crystallization: α-Al, SrAl 4 , SrAl 2 Si 2 and Si. The system comprises a section of Al-SrAl 2 Si 2 representing a quasibinary system of an eutectic type. The eutectic reaction takes place at a temperature of 640 deg C. The quasibinary Al-SrAl 2 Si 2 section divides the aluminium corner of the Sr-Al-Si system into two independent systems Al-SrAl 4 -SrAl 2 Si 2 and Al-Si-SrAl 2 Si 2 of an eutectic type

Characterisation of airborne dust in a gold mine

International Nuclear Information System (INIS)

Annegarn, H.J.; Symons, G.; Zucchiatti, A.; Booth-Jones, P.; Storms, H.

1984-01-01

Samples of airborne dust were collected from a gold mine using a single orifice cascade impactor. The size fractionated dust samples were analysed by Particle Induced X-ray Emission (PIXE) and Electron Probe X-ray Micro-Analysis (EPXMA). Results on chemical composition of the sub-micron, inhalable dust were obtained. In addition ot quartz dust, a large fraction consisted of chlorine containing particles. The filter grade efficiency of a spray cooling chamber was calculated as a function of particle size

Experimental determination of the unattached radon daughter fraction and dust size distribution in some Canadian uranium mines

International Nuclear Information System (INIS)

Bigu, J.; Kirk, J.

1982-01-01

The unattached radon daughter fraction has been experimentally determined in some Canadian uranium mines. Two experimental methods have been used, the wire screen method and a diffusion sampler based on Mercer's theory of diffusional deposition on parallel circular plates. Experiments were conducted in 'non-diesel' and 'diesel' areas of the mines, i.e. locations where mining was done with diesel machinery. Unattached fractions ranged from about 2-8 per cent for non-diesel area. For diesel areas the unattached fraction was substantially lower, less than about one per cent. The aerosol concentration in the range 0.0015 - 0.13 μm was measured with a condensation nuclei counter. Dust concentration was determined with conventional samplers. Particle size distribution in the respirable range was determined with a fine particle spectrometer in conjunction with eriometric techniques

Aluminium in human sweat.

Science.gov (United States)

Minshall, Clare; Nadal, Jodie; Exley, Christopher

2014-01-01

It is of burgeoning importance that the human body burden of aluminium is understood and is measured. There are surprisingly few data to describe human excretion of systemic aluminium and almost no reliable data which relate to aluminium in sweat. We have measured the aluminium content of sweat in 20 healthy volunteers following mild exercise. The concentration of aluminium ranged from 329 to 5329μg/L. These data equate to a daily excretion of between 234 and 7192μg aluminium and they strongly suggest that perspiration is the major route of excretion of systemic aluminium in humans. Copyright © 2013 Elsevier GmbH. All rights reserved.

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

International Nuclear Information System (INIS)

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

2008-01-01

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 (AlCl 3 ), Al 13 polynuclear cluster ([Al 13 O 4 (OH) 24 (H 2 O) 12 ] 7+ ), Al 30 polynuclear cluster ([Al 30 O 8 (OH) 56 (H 2 O) 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, NH 3 , NaHCO 3 , Na 2 CO 3 and KOH). The results of the potentiometric analysis have been cross-verified by quantitative 27 Al solution nuclear magnetic resonance ( 27 Al 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

Lyα Profile, Dust, and Prediction of Lyα Escape Fraction in Green Pea Galaxies

Science.gov (United States)

Yang, Huan; Malhotra, Sangeeta; Gronke, Max; Rhoads, James E.; Leitherer, Claus; Wofford, Aida; Jiang, Tianxing; Dijkstra, Mark; Tilvi, V.; Wang, Junxian

2017-08-01

We studied Lyman-α (Lyα) escape in a statistical sample of 43 Green Peas with HST/COS Lyα spectra. Green Peas are nearby star-forming galaxies with strong [O III]λ5007 emission lines. Our sample is four times larger than the previous sample and covers a much more complete range of Green Pea properties. We found that about two-thirds of Green Peas are strong Lyα line emitters with rest-frame Lyα equivalent width > 20 \\mathringA . The Lyα profiles of Green Peas are diverse. The Lyα escape fraction, defined as the ratio of observed Lyα flux to intrinsic Lyα flux, shows anti-correlations with a few Lyα kinematic features—both the blue peak and red peak velocities, the peak separations, and the FWHM of the red portion of the Lyα profile. Using properties measured from Sloan Digital Sky Survey optical spectra, we found many correlations—the Lyα escape fraction generally increases at lower dust reddening, lower metallicity, lower stellar mass, and higher [O III]/[O II] ratio. We fit their Lyα profiles with the H I shell radiative transfer model and found that the Lyα escape fraction is anti-correlated with the best-fit N H I . Finally, we fit an empirical linear relation to predict {f}{esc}{Lyα } from the dust extinction and Lyα red peak velocity. The standard deviation of this relation is about 0.3 dex. This relation can be used to isolate the effect of intergalactic medium (IGM) scatterings from Lyα escape and to probe the IGM optical depth along the line of sight of each z> 7 Lyα emission-line galaxy in the James Webb Space Telescope era.

The most luminous heavily obscured quasars have a high merger fraction: morphological study of wise -selected hot dust-obscured galaxies

Energy Technology Data Exchange (ETDEWEB)

Fan, Lulu; Gao, Ying; Zhang, Dandan; Jiang, Xiaoming; Wu, Qiaoqian; Yang, Jun; Li, Zhao [Shandong Provincial Key Lab of Optical Astronomy and Solar-Terrestrial Environment, Institute of Space Science, Shandong University, Weihai 264209 (China); Han, Yunkun [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China); Fang, Guanwen, E-mail: llfan@sdu.edu.cn, E-mail: hanyk@ynao.ac.cn [Institute for Astronomy and History of Science and Technology, Dali University, Dali 671003 (China)

2016-05-10

Previous studies have shown that Wide-field Infrared Survey Explorer -selected hyperluminous, hot dust-obscured galaxies (Hot DOGs) are powered by highly dust-obscured, possibly Compton-thick active galactic nuclei (AGNs). High obscuration provides us a good chance to study the host morphology of the most luminous AGNs directly. We analyze the host morphology of 18 Hot DOGs at z ∼ 3 using Hubble Space Telescope /WFC3 imaging. We find that Hot DOGs have a high merger fraction (62 ± 14%). By fitting the surface brightness profiles, we find that the distribution of Sérsic indices in our Hot DOG sample peaks around 2, which suggests that most Hot DOGs have transforming morphologies. We also derive the AGN bolometric luminosity (∼10{sup 14} L {sub ⊙}) of our Hot DOG sample by using IR spectral energy distributions decomposition. The derived merger fraction and AGN bolometric luminosity relation is well consistent with the variability-based model prediction. Both the high merger fraction in an IR-luminous AGN sample and relatively low merger fraction in a UV/optical-selected, unobscured AGN sample can be expected in the merger-driven evolutionary model. Finally, we conclude that Hot DOGs are merger-driven and may represent a transit phase during the evolution of massive galaxies, transforming from the dusty starburst-dominated phase to the unobscured QSO phase.

Preparation of Ti-aluminide reinforced in situ aluminium matrix composites by reactive hot pressing

International Nuclear Information System (INIS)

Roy, D.; Ghosh, S.; Basumallick, A.; Basu, B.

2007-01-01

Aluminium based metal matrix composites reinforced with in situ Ti-aluminide and alumina particles were prepared by reactive hot pressing a powder mix of aluminium and nanosized TiO 2 powders. The reinforcements were formed in situ by exothermal reaction between the TiO 2 nano crystalline powder and aluminium. The thermal characteristics of the in situ reaction were studied with the aid of Differential scanning calorimetry (DSC). X-ray diffraction (XRD), Energy dispersive spectroscopy (EDS) and Scanning electron microscopy (SEM) techniques were employed to study the microstructural architecture of the composites as a function of hot pressing temperature and volume percent reinforcement. Microhardness measurements on the as prepared in situ aluminium matrix composites exhibit significant increase in hardness with increase in hot pressing temperature and volume fraction of reinforcement

Respirable versus inhalable dust sampling

International Nuclear Information System (INIS)

Hondros, J.

1987-01-01

The ICRP uses a total inhalable dust figure as the basis of calculations on employee lung dose. This paper was written to look at one aspect of the Olympic Dam dust situation, namely, the inhalable versus respirable fraction of the dust cloud. The results of this study will determine whether it is possible to use respirable dust figures, as obtained during routine monitoring to help in the calculations of employee exposure to internal radioactive contaminants

Assessment of occupational exposure to wood dust in the Polish furniture industry

Directory of Open Access Journals (Sweden)

Małgorzata Szewczyńska

2017-02-01

Full Text Available Background: Occupational exposure to wood dust can be responsible for many different harmful health effects, especially in workers employed in the wood industry. The assessment of wood dust adverse effects to humans, as well as the interpretation of its concentration measurements carried out to assess potential occupational exposure are very difficult. First of all, it is due to possible occurrence of different kind of wood dust in the workplace air, namely wood dust from dozens of species of trees belonging to 2 kinds of botanical gymnosperms and angiosperms, as well as to its different chemical composition. Material and Methods: Total dust and respirable wood dust in the workplace air in the furniture industry was determined using the filtration-gravimetric method in accordance with Polish Standards PN-Z-04030-05:1991 and PN-Z-04030-06:1991. Air samples were collected based on the principles of individual dosimetry. Results: Total dust concentrations were 0.84–13.92 mg/m3 and inhalable fraction concentrations, obtained after the conversion of total dust by applying a conversion factor of 1.59, were 1.34–22.13 mg/m3. Respirable fraction concentrations were 0.38–4.04 mg/m3, which makes approx. 25% of the inhalable fraction on average. The highest concentrations occurred in grinding and the lowest during milling processes of materials used in the manufacture of furniture. Conclusions: The results indicate that the share of respirable fraction in the inhalable fraction of wood dust is considerable. Due to the determination of the threshold limit value (TLV for the inhalable fraction of wood dust, it is necessary to replace the previously used samplers for total dust with samplers that provide quantitative separation of wood dust inhalable fractions in accordance with the convention of this fraction as defined in PN-EN 481:1998. Med Pr 2017;68(1:45–60

[Assessment of occupational exposure to wood dust in the Polish furniture industry].

Science.gov (United States)

Szewczyńska, Małgorzata; Pośniak, Małgorzata

2017-02-28

Occupational exposure to wood dust can be responsible for many different harmful health effects, especially in workers employed in the wood industry. The assessment of wood dust adverse effects to humans, as well as the interpretation of its concentration measurements carried out to assess potential occupational exposure are very difficult. First of all, it is due to possible occurrence of different kind of wood dust in the workplace air, namely wood dust from dozens of species of trees belonging to 2 kinds of botanical gymnosperms and angiosperms, as well as to its different chemical composition. Total dust and respirable wood dust in the workplace air in the furniture industry was determined using the filtration-gravimetric method in accordance with Polish Standards PN-Z-04030-05:1991 and PN-Z-04030-06:1991. Air samples were collected based on the principles of individual dosimetry. Total dust concentrations were 0.84-13.92 mg/m3 and inhalable fraction concentrations, obtained after the conversion of total dust by applying a conversion factor of 1.59, were 1.34-22.13 mg/m3. Respirable fraction concentrations were 0.38-4.04 mg/m3, which makes approx. 25% of the inhalable fraction on average. The highest concentrations occurred in grinding and the lowest during milling processes of materials used in the manufacture of furniture. The results indicate that the share of respirable fraction in the inhalable fraction of wood dust is considerable. Due to the determination of the threshold limit value (TLV) for the inhalable fraction of wood dust, it is necessary to replace the previously used samplers for total dust with samplers that provide quantitative separation of wood dust inhalable fractions in accordance with the convention of this fraction as defined in PN-EN 481:1998. Med Pr 2017;68(1):45-60. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

Cometary Dust

Science.gov (United States)

Levasseur-Regourd, Anny-Chantal; Agarwal, Jessica; Cottin, Hervé; Engrand, Cécile; Flynn, George; Fulle, Marco; Gombosi, Tamas; Langevin, Yves; Lasue, Jérémie; Mannel, Thurid; Merouane, Sihane; Poch, Olivier; Thomas, Nicolas; Westphal, Andrew

2018-04-01

This review presents our understanding of cometary dust at the end of 2017. For decades, insight about the dust ejected by nuclei of comets had stemmed from remote observations from Earth or Earth's orbit, and from flybys, including the samples of dust returned to Earth for laboratory studies by the Stardust return capsule. The long-duration Rosetta mission has recently provided a huge and unique amount of data, obtained using numerous instruments, including innovative dust instruments, over a wide range of distances from the Sun and from the nucleus. The diverse approaches available to study dust in comets, together with the related theoretical and experimental studies, provide evidence of the composition and physical properties of dust particles, e.g., the presence of a large fraction of carbon in macromolecules, and of aggregates on a wide range of scales. The results have opened vivid discussions on the variety of dust-release processes and on the diversity of dust properties in comets, as well as on the formation of cometary dust, and on its presence in the near-Earth interplanetary medium. These discussions stress the significance of future explorations as a way to decipher the formation and evolution of our Solar System.

Occurrence of polycyclic aromatic hydrocarbons in dust emitted from circulating fluidized bed boilers.

Science.gov (United States)

Kozielska, B; Konieczyńiski, J

2008-11-01

Occurrence of polycyclic aromatic hydrocarbons (PAHs) in granulometric fractions of dust emitted from a hard coal fired circulating fluidized bed (CFB) boiler was investigated. The dust was sampled with the use of a Mark III impactor. In each fraction of dust, by using gas chromatography (GC), 16 selected PAHs and total PAHs were determined and the toxic equivalent B(a)P (TE B(a)P) was computed. The results, recalculated for the standard granulometric fractions, are presented as concentrations and content of the determined PAHs in dust. Distributions of PAHs and their profiles in the granulometric dust fractions were studied also. The PAHs in dust emitted from the CFB boiler were compared with those emitted from mechanical grate boilers; a distinctly lower content of PAHs was found in dust emitted from the former.

Effect of Lubrication on Sliding Wear of Red Mud Particulate Reinforced Aluminium Alloy 6061

Directory of Open Access Journals (Sweden)

N. Panwar

2017-09-01

Full Text Available In present study, Red mud, an industrial waste, has been utilized as a reinforcement material to fabricate Aluminium 6061 matrix based metal matrix composite. Taguchi L18 orthogonal array has been employed for fabrication of composite castings and for conducting the tribological experimentation. ANOVA analysis has been applied to examine the effect of individual parameters such as sliding condition: dry and wet, reinforcement weight fraction, load, speed, and sliding distance on specific wear rate obtained experimentally. It has been found that tensile strength and impact energy increases while elongation decreases, with increasing weight fraction and decrease in particle size of red mud. The percentage contribution of the effect of factors on SWR is Sliding condition (73.17, speed (7.84, percentage reinforcement (7.35, load (5.75, sliding distance (2.24, and particle size (1.25. It has also been observed that specific wear rate is very low in wet condition. However, it decreases with increase in weight fraction of reinforcement, decrease in load and sliding speed. Al6061/red mud metal matrix composites have shown reasonable strength and wear resistance. The use of red mud in Aluminium composite provides the solution for disposal of red mud and can possibly become an economic replacement of Aluminium and its alloys.

Grain size effect on Sr and Nd isotopic compositions in eolian dust. Implications for tracing dust provenance and Nd model age

International Nuclear Information System (INIS)

Feng Jinliang; Zhu Liping; Zhen Xiaolin; Hu Zhaoguo

2009-01-01

Strontium (Sr) and neodymium (Nd) isotopic compositions enable identification of dust sources and reconstruction of atmospheric dispersal pathways. The Sr and Nd isotopic compositions in eolian dust change systematically with grain size in ways not yet fully understood. This study demonstrates the grain size effect on the Sr and Nd isotopic compositions in loess and 2006 dust fall, based on analyses of seven separated grain size fractions. The analytical results indicate that Sr isotopic ratios strongly depend on the grain size fractions in samples from all types of eolian dust. In contrast, the Nd isotopic ratios exhibit little variation in loess, although they vary significantly with grain size in samples from a 2006 dust fall. Furthermore, Nd model ages tend to increase with increasing grain size in samples from all types of eolian dust. Comparatively, Sr isotopic compositions exhibit high sensitively to wind sorting, while Nd isotopic compositions show greater sensitively to dust origin. The principal cause for the different patterns of Sr and Nd isotopic composition variability with grain size appears related to the different geochemical behaviors between rubidium (Rb) and Sr, and the similar geochemical behaviors between samarium (Sm) and Nd. The Nd isotope data indicate that the various grain size fractions in loess have similar origins for each sample. In contrast, various provenance components may separate into different grain size fractions for the studied 2006 dust fall. The Sr and Nd isotope compositions further confirm that the 2006 dust fall and Pleistocene loess in Beijing have different sources. The loess deposits found in Beijing and those found on the Chinese Loess Plateau also derive from different sources. Variations between Sr and Nd isotopic compositions and Nd model ages with grain size need to be considered when directly comparing analyses of eolian dust of different grain size. (author)

Human exposure to aluminium.

Science.gov (United States)

Exley, Christopher

2013-10-01

Human activities have circumvented the efficient geochemical cycling of aluminium within the lithosphere and therewith opened a door, which was previously only ajar, onto the biotic cycle to instigate and promote the accumulation of aluminium in biota and especially humans. Neither these relatively recent activities nor the entry of aluminium into the living cycle are showing any signs of abating and it is thus now imperative that we understand as fully as possible how humans are exposed to aluminium and the future consequences of a burgeoning exposure and body burden. The aluminium age is upon us and there is now an urgent need to understand how to live safely and effectively with aluminium.

Determination of Aluminium Content in Aluminium Hydroxide Formulation by FT-NIR Transmittance Spectroscopy

DEFF Research Database (Denmark)

Lai, Xuxin; Zheng, Yiwu; Søndergaard, Ib

2007-01-01

A method for determining the aluminium content of an aluminium hydroxide suspension using near infrared (NIR) transmittance spectroscopy has been developed. Inductively coupled plasma-atomic emission spectroscopy (ICP-AES) was used as reference method. The factors influencing the NIR analysis...... aluminium content in aluminium hydroxide suspension. (c) 2007 Elsevier Ltd. All rights reserved....

Effect of Bio char on Plant Growth and Aluminium Form of Soil under Aluminium Stress

Science.gov (United States)

Qian, Lianwen; Li, Qingbiao; Sun, Jingwei; Feng, Ying

2018-01-01

Aluminium-enriched acid red soils in South China easily cause aluminium toxicity to plants, but biochip can improve soils and eliminate soil contaminations. In this project, biochip was used in potted plant control test to study the effect of biochip on plant growth in soil under acid aluminium stress and the migration and conversion of aluminium in plant-soil system. The fin dings show that the application of biochip increases the pH value of soil under aluminium stress significantly, changes the existing form of aluminium ion in soil, reduces the plants’ absorption of aluminium, and alleviates the aluminium toxicity to plants, but too much biochip may inhibit the growth of plants. In this case, further study should be carried out as regards the volume and way of biochip input in practical applications as well as the timeliness of aluminium toxicity removal.

Physical properties of five grain dust types.

OpenAIRE

Parnell, C B; Jones, D D; Rutherford, R D; Goforth, K J

1986-01-01

Physical properties of grain dust derived from five grain types (soybean, rice, corn, wheat, and sorghum) were measured and reported. The grain dusts were obtained from dust collection systems of terminal grain handling facilities and were assumed to be representative of grain dust generated during the handling process. The physical properties reported were as follows: particle size distributions and surface area measurements using a Coulter Counter Model TAII; percent dust fractions less tha...

Confined recrystallization of high-purity aluminium during accumulative roll bonding of aluminium laminates

International Nuclear Information System (INIS)

Chekhonin, Paul; Beausir, Benoît; Scharnweber, Juliane; Oertel, Carl-Georg; Hausöl, Tina; Höppel, Heinz Werner; Brokmeier, Heinz-Günter; Skrotzki, Werner

2012-01-01

Aluminium laminates consisting of high-purity aluminium and commercially pure aluminium have been produced by accumulative roll bonding (ARB) at ambient temperature for up to 10 cycles. To study the microstructure and texture development of the high-purity aluminium layers with regard to the shrinking layer thickness during ARB, microstructure and texture investigations were carried out by electron backscatter diffraction and neutron and X-ray diffraction, respectively. While the commercially pure aluminium layers develop an ultrafine-grained microstructure, partial discontinuous recrystallization occurs in the high-purity layers. The texture of the high-purity layers mainly consists of Cube and “Tilted Cube” (tilted with respect to the transverse direction) components. The experimental results are discussed with respect to confined recrystallization in the ARB aluminium laminates.

Alloys of uranium and aluminium with low aluminium content

International Nuclear Information System (INIS)

Cabane, G.; Englander, M.; Lehmann, J.

1955-01-01

Uranium, as obtained after spinning in phase γ, presents an heterogeneous structure with large size grains. The anisotropic structure of the metal leads to an important buckling and surface distortion of the fuel slug which is incompatible with its tubular cladding for nuclear fuel uses. Different treatments have been made to obtain an isotropic structure presenting high thermal stability (laminating, hammering and spinning in phase α) without success. Alloys of uranium and aluminium with low aluminium content present important advantage in respect of non allied uranium. The introduction of aluminium in the form of intermetallic compound (UAl 2 ) gives a better resistance to thermal fatigue. Alloys obtained from raw casting present an improved buckling and surface distortion in respect of pure uranium. This improvement is obtained with uranium containing between 0,15 and 0,5 % of aluminium. An even more improvement in thermal stability is obtained by thermal treatments of these alloys. These new characteristics are explained by the fine dispersion of the UAl 2 particles in uranium. The results after treatments obtained from an alloy slug containing 0,4 % of aluminium show no buckling or surface distortion and no elongation. (M.P.)

Phase transformation of aluminium hydroxide to aα- alumina prepared from different aluminium salts

International Nuclear Information System (INIS)

Masliana Muslimin; Meor Yusoff Meor Sulaiman

2006-01-01

The study intends to look at the most suitable aluminium salt to produce a single-phase a-alumina by the hydrothermal method. In the process to produce alumina from the calcination of aluminium hydroxide (Al(OH) 3 ), three different aluminium salts namely aluminium sulfate (Al 2 (SO 4) 2), aluminium nitrate (A(NO 3 ) 3 ) and aluminium chloride (AlCl 3 ) were tried. The process involved the used of NH 4 OH as the precipitating medium. Aluminium hydroxide produced from each of these salts were characterised by x-ray diffraction (XRD) technique to identity the crystalline phase. Aluminium hydroxide produced by all the different aluminium salts is present as boehmite or pseudo-boehmite phase. Aluminium hydroxide produced from Al 2 (SO) 2 , Al(NO) 3 and AlCl 3 shows the transformation of the boehmite phase to a α-alumina phase at 500 0 C. On further heating, the α-alumina continuously formed at 800 o C followed soon at 1000 o C. But for the Al(NO3) 3 salts a different phase transitions occurs on heating especially at 1000 o C. Here it was observed not a single alumina phase is presence but the presence of both α and γ--alumina phases. At 1300 o C, the single α-alumina phase was formed. The study concluded that aluminium sulphate is recommended in order to obtain a single-phase α-alumina with the required characteristics. (Author)

Physical properties of five grain dust types.

Science.gov (United States)

Parnell, C B; Jones, D D; Rutherford, R D; Goforth, K J

1986-01-01

Physical properties of grain dust derived from five grain types (soybean, rice, corn, wheat, and sorghum) were measured and reported. The grain dusts were obtained from dust collection systems of terminal grain handling facilities and were assumed to be representative of grain dust generated during the handling process. The physical properties reported were as follows: particle size distributions and surface area measurements using a Coulter Counter Model TAII; percent dust fractions less than 100 micron of whole dust; bulk density; particle density; and ash content. PMID:3709482

Recycling of steelmaking dusts: The Radust concept

Directory of Open Access Journals (Sweden)

Jalkanen H.

2005-01-01

Full Text Available Recycling of dusts and other wastes of steelmaking is becoming to a necessity of two reasons: due to high contents of iron oxides dusts are valuable raw material for steelmaking and tightening environmental legislation makes the landfill disposal of wastes more expensive. Fine dust fractions from various stages of steelmaking route contain besides iron and carbon heavy metals especially zinc and lead and heavy hydrocarbons that are acceptable neither for landfill disposal nor for recycling back to processes without any spe4cial treatments. Some theoretical and practical aspects concerning high temperature treatments of steelmaking dusts for removal of hazardous components and production of clean high iron raw material for recycling is discussed in this paper. The Radust technology developed at Koverhar steelwork in Finland for treatment of the most problematic fine fractions of blast furnace and oxygen converter dusts is shortly presented and discussed.

Coprecipitation of yttrium and aluminium hydroxide for preparation of yttrium aluminium garnet

NARCIS (Netherlands)

Vrolijk, J.W.G.A.; Willems, J.W.M.M.; Metselaar, R.

1990-01-01

Coprecipitation of yttrium and aluminium hydroxide for the preparation of pure yttrium aluminium garnet (YAG) powder with small grain size is the subject of this study. Starting materials are sulphates and chlorides of yttrium and aluminium. To obtain pure YAG (Y3Al5O12), the pH during flocculation

Wear Behavior of Aluminium Metal Matrix Composite Prepared from Industrial Waste

Directory of Open Access Journals (Sweden)

L. Francis Xavier

2016-01-01

Full Text Available With an increase in the population and industrialization, a lot of valuable natural resources are depleted to prepare and manufacture products. However industrialization on the other hand has waste disposal issues, causing dust and environmental pollution. In this work, Aluminium Metal Matrix Composite is prepared by reinforcing 10 wt% and 20 wt% of wet grinder stone dust particles an industrial waste obtained during processing of quarry rocks which are available in nature. In the composite materials design wear is a very important criterion requiring consideration which ensures the materials reliability in applications where they come in contact with the environment and other surfaces. Dry sliding wear test was carried out using pin-on-disc apparatus on the prepared composites. The results reveal that increasing the reinforcement content from 10 wt% to 20 wt% increases the resistance to wear rate.

A fractionally cointegrated VAR analysis of price discovery in commodity futures markets

DEFF Research Database (Denmark)

Dolatabadi, Sepideh; Nielsen, Morten Ørregaard; Xu, Ke

straightforward examination of the adjustment coefficients. In our empirical analysis we use the data from Figuerola-Ferretti and Gonzalo (2010), who conduct a similar analysis using the usual (non-fractional) CVAR model. Our first finding is that, for all markets except copper, the fractional integration......In this paper we apply the recently developed fractionally cointegrated vector autoregressive (FCVAR) model to analyze price discovery in the spot and futures markets for five non-ferrous metals (aluminium, copper, lead, nickel, and zinc). The FCVAR model allows for long memory (fractional...... to the results from the non-fractional model, we find slightly more evidence of price discovery in the spot market. Specifically, using standard likelihood ratio tests, we do not reject the hypothesis that price discovery takes place exclusively in the spot (futures) market for copper, lead, and zinc (aluminium...

Toxicity of aluminium on five aquatic invertebrates; Aluminiums toksisitet paa 5 akvatiske invertebrater

Energy Technology Data Exchange (ETDEWEB)

Moe, J [Oslo Univ. (Norway)

1996-01-01

The conference paper deals with the experiments done by investigating the effects from the toxicity of aluminium on aquatic invertebrates. The aim of the experiments was to compare the toxicity of unstable aluminium compounds with stable forms of aluminium. 8 refs., 2 figs., 2 tabs.

Air pollution assessment based on elemental concentration of leaves tissue and foliage dust along an urbanization gradient in Vienna

International Nuclear Information System (INIS)

Simon, Edina; Braun, Mihaly; Vidic, Andreas; Bogyo, David; Fabian, Istvan; Tothmeresz, Bela

2011-01-01

Foliage dust contains heavy metal that may have harmful effects on human health. The elemental contents of tree leaves and foliage dust are especially useful to assess air environmental pollution. We studied the elemental concentrations in foliage dust and leaves of Acer pseudoplatanus along an urbanization gradient in Vienna, Austria. Samples were collected from urban, suburban and rural areas. We analysed 19 elements in both kind of samples: aluminium, barium, calcium, copper, iron, potassium, magnesium, sodium, phosphor, sulphur, strontium and zinc. We found that the elemental concentrations of foliage dust were significantly higher in the urban area than in the rural area for aluminium, barium, iron, lead, phosphor and selenium. Elemental concentrations of leaves were significantly higher in urban than in rural area for manganese and strontium. Urbanization changed significantly the elemental concentrations of foliage dust and leaves and the applied method can be useful for monitoring the environmental load. - Highlights: → We studied the elements in dust and leaves along an urbanization gradient, Austria. → We analysed 19 elements: Al, Ba, Ca, Cd, Cu, Fe, K, Mg, Na, P, Pb, S, Sr and Zn. → Elemental concentrations were higher in urban area than in the rural area. → Studied areas were separated by CDA based on the elemental concentrations. → Dust and leaves can be useful for monitoring the environmental load. - Studying the elements (Al, Ba, Ca, Cu, Fe, K, Mg, Na, P, S, Sr, Zn) in dust and leaves along an urbanization gradient in Wien, Austria we found that the elemental concentrations of foliage dust were significantly higher in the urban area than in the rural area for Al, Ba, Fe, Pb, P and Se, and concentrations of leaves were significantly higher in urban than in rural area for Mn and Sr.

Air pollution assessment based on elemental concentration of leaves tissue and foliage dust along an urbanization gradient in Vienna

Energy Technology Data Exchange (ETDEWEB)

Simon, Edina, E-mail: edina.simon@gmail.com [Department of Ecology, University of Debrecen, H-4010 Debrecen, P.O. Box 71 (Hungary); Braun, Mihaly [Department of Inorganic and Analytical Chemistry, University of Debrecen, H-4010 Debrecen, P.O. Box 21 (Hungary); Vidic, Andreas [Department fuer Naturschutzbiologie, Vegetations- und Landschaftsoekologie, Universitat Wien, Althanstrasse 14, 1090 Wien (Austria); Bogyo, David [Department of Ecology, University of Debrecen, H-4010 Debrecen, P.O. Box 71 (Hungary); Fabian, Istvan [Department of Inorganic and Analytical Chemistry, University of Debrecen, H-4010 Debrecen, P.O. Box 21 (Hungary); Tothmeresz, Bela [Department of Ecology, University of Debrecen, H-4010 Debrecen, P.O. Box 71 (Hungary)

2011-05-15

Foliage dust contains heavy metal that may have harmful effects on human health. The elemental contents of tree leaves and foliage dust are especially useful to assess air environmental pollution. We studied the elemental concentrations in foliage dust and leaves of Acer pseudoplatanus along an urbanization gradient in Vienna, Austria. Samples were collected from urban, suburban and rural areas. We analysed 19 elements in both kind of samples: aluminium, barium, calcium, copper, iron, potassium, magnesium, sodium, phosphor, sulphur, strontium and zinc. We found that the elemental concentrations of foliage dust were significantly higher in the urban area than in the rural area for aluminium, barium, iron, lead, phosphor and selenium. Elemental concentrations of leaves were significantly higher in urban than in rural area for manganese and strontium. Urbanization changed significantly the elemental concentrations of foliage dust and leaves and the applied method can be useful for monitoring the environmental load. - Highlights: > We studied the elements in dust and leaves along an urbanization gradient, Austria. > We analysed 19 elements: Al, Ba, Ca, Cd, Cu, Fe, K, Mg, Na, P, Pb, S, Sr and Zn. > Elemental concentrations were higher in urban area than in the rural area. > Studied areas were separated by CDA based on the elemental concentrations. > Dust and leaves can be useful for monitoring the environmental load. - Studying the elements (Al, Ba, Ca, Cu, Fe, K, Mg, Na, P, S, Sr, Zn) in dust and leaves along an urbanization gradient in Wien, Austria we found that the elemental concentrations of foliage dust were significantly higher in the urban area than in the rural area for Al, Ba, Fe, Pb, P and Se, and concentrations of leaves were significantly higher in urban than in rural area for Mn and Sr.

The prophylactic reduction of aluminium intake.

Science.gov (United States)

Lione, A

1983-02-01

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.

Influence of Saharan dust outbreaks and carbon content on oxidative potential of water-soluble fractions of PM2.5 and PM10

Science.gov (United States)

Chirizzi, Daniela; Cesari, Daniela; Guascito, Maria Rachele; Dinoi, Adelaide; Giotta, Livia; Donateo, Antonio; Contini, Daniele

2017-08-01

Exposure to atmospheric particulate matter (PM) leads to adverse health effects although the exact mechanisms of toxicity are still poorly understood. Several studies suggested that a large number of PM health effects could be due to the oxidative potential (OP) of ambient particles leading to high concentrations of reactive oxygen species (ROS). The contribution to OP of specific anthropogenic sources like road traffic, biomass burning, and industrial emissions has been investigated in several sites. However, information about the OP of natural sources are scarce and no data is available regarding the OP during Saharan dust outbreaks (SDO) in Mediterranean regions. This work uses the a-cellular DTT (dithiothreitol) assay to evaluate OP of the water-soluble fraction of PM2.5 and PM10 collected at an urban background site in Southern Italy. OP values in three groups of samples were compared: standard characterised by concentrations similar to the yearly averages; high carbon samples associated to combustion sources (mainly road traffic and biomass burning) and SDO events. DTT activity normalised by sampled air volume (DTTV), representative of personal exposure, and normalised by collected aerosol mass (DTTM), representing source-specific characteristics, were investigated. The DTTV is larger for high PM concentrations. DTTV is well correlated with secondary organic carbon concentration. An increased DTTV response was found for PM2.5 compared to the coarse fraction PM2.5-10. DTTV is larger for high carbon content samples but during SDO events is statistically comparable with that of standard samples. DTTM is larger for PM2.5 compared to PM10 and the relative difference between the two size fractions is maximised during SDO events. This indicates that Saharan dust advection is a natural source of particles having a lower specific OP with respect to the other sources acting on the area (for water-soluble fraction). OP should be taken into account in epidemiological

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

Science.gov (United States)

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

1972-01-01

Thin foils of high purity aluminium and an Al-Al2O3 SAP type of alloy were oxidised in a specially designed hot stage specimen chamber in an electron microscope. Below 450 C, amorphous aluminium oxide formed on the foil surface and was first detectable at foil edges, holes, and pits. Islands of aluminium then nucleated in this amorphous oxide. The aluminium islands displayed either a lateral growth with eventual coalescence with other islands, or a reoxidation process which caused the islands to disappear. The aluminium island formation was determined to be related to the presence of the electron beam. A mechanism based upon electron charging due to the electron beam was proposed to explain the nucleation, growth, coalescence, disappearance, and geometry of the aluminium islands.

TEM investigation of aluminium containing precipitates in high aluminium doped silicon carbide

International Nuclear Information System (INIS)

Wong-Leung, J.; FitzGerald, J.D.

2002-01-01

Full text: Silicon carbide is a promising semiconductor material for applications in high temperature and high power devices. The successful growth of good quality epilayers in this material has enhanced its potential for device applications. As a novel semiconductor material, there is a need for studying its basic physical properties and the role of dopants in this material. In this study, silicon carbide epilayers were grown on 4H-SiC wafers of (0001) orientation with a miscut angle of 8 deg at a temperature of 1550 deg C. The epilayers contained regions of high aluminium doping well above the solubility of aluminium in silicon carbide. High temperature annealing of this material resulted in the precipitation of aluminium in the wafers. The samples were analysed by secondary ion mass spectrometry and transmission electron microscopy. Selected area diffraction studies show the presence of aluminium carbide and aluminium silicon carbide phases. Copyright (2002) Australian Society for Electron Microscopy Inc

Respirable quartz hazard associated with coal mine roof bolter dust

International Nuclear Information System (INIS)

Joy, G.J.; Beck, T.W.; Listak, J.M.

2010-01-01

Pneumoconiosis has been reported to be increasing among underground coal miners in the Southern Appalachian Region. The National Institute for Occupational Safety and Health conducted a study to examine the particle size distribution and quartz content of dust generated by the installation of roof bolts in mines. Forty-six bulk samples of roof bolting machine pre-cleaner cyclone dump dust and collector box dust were collected from 26 underground coal mines. Real-time and integrated airborne respirable dust concentrations were measured on 3 mining sections in 2 mines. The real-time airborne dust concentrations profiles were examined to identify any concentration changes that might be associated with pre-cleaner cyclone dust discharge events. The study showed that bolter dust is a potential inhalation hazard due to the fraction of dust less than 10 μm in size, and the quartz content of the dust. The pre-cleaner cyclone dust was significantly larger than the collector box dust, indicating that the pre-cleaner functioned properly in removing the larger dust size fraction from the airstream. However, the pre-cleaner dust still contained a substantial amount of respirable dust. It was concluded that in order to maintain the effectiveness of a roof bolter dust collector, periodic removal of dust is required. Appropriate work procedures and equipment are necessary to minimize exposure during this cleaning task. 13 refs., 3 tabs., 2 figs.

Regularities of dust formation during stone cutting for construction works

Directory of Open Access Journals (Sweden)

V.G. Lebedev

2016-09-01

Full Text Available When cutting stone, a large amount of dust release, which is a mixture of small, mostly sharp, mineral particles. Shallow dry dust with inhalation causes the pathological changes in organs that are a consequence of infiltration of acute and solids particles. Despite the importance of this problem, the questions of dust generation during the various working processes and its fractions distribution are practically not considered. This determines the time of dust standing in the air and its negative impact on a person. Aim: The aim of this research is to study the process of dusting during stones cutting and dust distribution on fractions regularities and quantification of dust formation process in order to improve the production equipment, staff individual and collective safety equipment. Materials and Methods: Many types of cutting can be divided into two types - a “dry” cutting and cutting with fluid. During “dry” cutting a dust represents a set of micro-chips which are cut off by the abrasive grains. The size of such chips very small: from a micrometer to a few micrometers fraction. Thus, the size of chips causes the possibility of creating dust slurry with low fall velocity, and which is located in the working space in large concentrations. Results: The following characteristic dependences were obtained as a result of research: dependence of the dust fall from the size of the dust particles, size of dust particles from minute feeding and grain range wheel, the specific amount of dust from the number of grit abrasive wheel and the temperature of the dust particles from the feeding at wheel turnover. It was shown that the distribution of chips (dust by size will request of a normal distribution low. Dimensions of chips during cut are in the range of 0.4...6 μm. Thus, dust slurry is formed with time of particles fall of several hours. This creates considerable minute dust concentration - within 0.28∙10^8...1.68∙10^8 units/m3.

Update on Automated Classification of Interplanetary Dust Particles

Science.gov (United States)

Maroger, I.; Lasue, J.; Zolensky, M.

2018-01-01

Every year, the Earth accretes about 40,000 tons of extraterrestrial material less than 1 mm in size on its surface. These dust particles originate from active comets, from impacts between asteroids and may also be coming from interstellar space for the very small particles. Since 1981, NASA Jonhson Space Center (JSC) has been systematically collecting the dust from Earth's strastosphere by airborne collectors and gathered them into "Cosmic Dust Catalogs". In those catalogs, a preliminary analysis of the dust particles based on SEM images, some geological characteristics and X-ray energy-dispersive spectrometry (EDS) composition is compiled. Based on those properties, the IDPs are classified into four main groups: C (Cosmic), TCN (Natural Terrestrial Contaminant), TCA (Artificial Terrestrial Contaminant) and AOS (Aluminium Oxide Sphere). Nevertheless, 20% of those particles remain ambiguously classified. Lasue et al. presented a methodology to help automatically classify the particles published in the catalog 15 based on their EDS spectra and nonlinear multivariate projections (as shown in Fig. 1). This work allowed to relabel 155 particles out of the 467 particles in catalog 15 and reclassify some contaminants as potential cosmic dusts. Further analyses of three such particles indicated their probable cosmic origin. The current work aims to bring complementary information to the automatic classification of IDPs to improve identification criteria.

'Nuisance Dust' - a Case for Recalibration?

Science.gov (United States)

Datson, Hugh; Marker, Brian

2013-04-01

This paper considers the case for a review and recalibration of limit values and acceptability criteria for 'nuisance dust', a widely encountered but poorly defined and regulated aspect of particulate matter pollution. Specific dust fractions such as PM10 and asbestiforms are well characterised and have limit values enshrined in legislation. National, and international, limit values for acceptable concentrations of PM10 and other fractions of particulate matter have been defined and agreed. In the United Kingdom (UK), these apply to both public and workplace exposures. By contrast, there is no standard definition or universal criteria against which acceptable levels for 'nuisance dust' can be assessed. This has implications for land-use planning and resource utilisation. Without meaningful limit values, inappropriate development might take place too near to residential dwellings or land containing economically important mineral resources may be effectively sterilised. Furthermore, the expression 'nuisance dust' is unhelpful in that 'nuisance' has a specific meaning in environmental law whilst 'nuisance dust' is often taken to mean 'generally visible particulate matter'. As such, it is associated with the social and broader environmental impacts of particulate matter. PM10 concentrations are usually expressed as a mass concentration over time. These can be determined using a range of techniques. While results from different instruments are generally comparable, data obtained from alternative methods for measuring 'nuisance dust' are rarely interchangeable. In the UK, many of the methods typically used are derived from approaches developed under the HMIP (Her Majesty's Inspectorate of Pollution) regime in the 1960s onwards. Typical methods for 'nuisance dust' sampling focus on measurement of dust mass (from the weight of dust collected in an open container over time) or dust soiling (from loss of reflectance and or obscuration of a surface discoloured by dust over

Analysis of aluminium in rat following administration of allergen immunotherapy using either aluminium or microcrystalline-tyrosine-based adjuvants.

Science.gov (United States)

McDougall, Stuart A; Heath, Matthew D; Kramer, Matthias F; Skinner, Murray A

2016-03-01

Investigation into the absorption, distribution and elimination of aluminium in rat after subcutaneous aluminium adjuvant formulation administration using ICP-MS is described. Assays were verified under the principles of a tiered approach. There was no evidence of systemic exposure of aluminium, in brain or in kidney. Extensive and persistent retention of aluminium at the dose site was observed for at least 180 days after administration. This is the first published work that has quantified aluminium adjuvant retention based on the quantity of aluminium delivered in a typical allergy immunotherapy course. The results indicate that the repeated administration of aluminium-containing adjuvants will likely contribute directly and significantly to an individual's body burden of aluminium.

TITANIUM CARBON ALUMINIUM : A NOVEL GRAIN REFINER FOR ALUMINIUM-LITHIUM ALLOYS

OpenAIRE

Birch , M.; Cowell , A.

1987-01-01

This work explores the possibility of achieving grain size control in aluminium-lithium alloys with the titanium carbon aluminium (TiCAl) master alloys invented at the Technical University of Berlin and developed by London and Scandinavian Metallurgical Co Ltd (LSM). Grain refining tests were conducted on a single batch of 8090 alloy using addition rates of 0.2wt% and 0.4wt% of TiCAl and 3/1 titanium boron aluminium (TiBAl). Other tests using 0.4wt% of binary TiAl gave poor results, showing t...

Reconciling PM10 analyses by different sampling methods for Iron King Mine tailings dust.

Science.gov (United States)

Li, Xu; Félix, Omar I; Gonzales, Patricia; Sáez, Avelino Eduardo; Ela, Wendell P

2016-03-01

The overall project objective at the Iron King Mine Superfund site is to determine the level and potential risk associated with heavy metal exposure of the proximate population emanating from the site's tailings pile. To provide sufficient size-fractioned dust for multi-discipline research studies, a dust generator was built and is now being used to generate size-fractioned dust samples for toxicity investigations using in vitro cell culture and animal exposure experiments as well as studies on geochemical characterization and bioassay solubilization with simulated lung and gastric fluid extractants. The objective of this study is to provide a robust method for source identification by comparing the tailing sample produced by dust generator and that collected by MOUDI sampler. As and Pb concentrations of the PM10 fraction in the MOUDI sample were much lower than in tailing samples produced by the dust generator, indicating a dilution of Iron King tailing dust by dust from other sources. For source apportionment purposes, single element concentration method was used based on the assumption that the PM10 fraction comes from a background source plus the Iron King tailing source. The method's conclusion that nearly all arsenic and lead in the PM10 dust fraction originated from the tailings substantiates our previous Pb and Sr isotope study conclusion. As and Pb showed a similar mass fraction from Iron King for all sites suggesting that As and Pb have the same major emission source. Further validation of this simple source apportionment method is needed based on other elements and sites.

Aluminium in Infrastructures

NARCIS (Netherlands)

Maljaars, J.

2016-01-01

Aluminium alloys are used in infrastructures such as pedestrian bridges or parts of it such as handrail. This paper demonstrates that aluminium alloys are in principle also suited for heavy loaded structures, such as decks of traffic bridges and helicopter landing platforms. Recent developments in

Comet 81p/Wild 2: The Updated Stardust Coma Dust Fluence Measurement for Smaller (Sub 10-Micrometre) Particles

Science.gov (United States)

Price, M. C.; Kearsley, A. T.; Burchell, M. J.; Horz, Friedrich; Cole, M. J.

2009-01-01

Micrometre and smaller scale dust within cometary comae can be observed by telescopic remote sensing spectroscopy [1] and the particle size and abundance can be measured by in situ spacecraft impact detectors [2]. Initial interpretation of the samples returned from comet 81P/Wild 2 by the Stardust spacecraft [3] appears to show that very fine dust contributes not only a small fraction of the solid mass, but is also relatively sparse [4], with a low negative power function describing grain size distribution, contrasting with an apparent abundance indicated by the on-board Dust Flux Monitor Instrument (DFMI) [5] operational during the encounter. For particles above 10 m diameter there is good correspondence between results from the DFMI and the particle size inferred from experimental calibration [6] of measured aerogel track and aluminium foil crater dimensions (as seen in Figure 4 of [4]). However, divergence between data-sets becomes apparent at smaller sizes, especially submicrometre, where the returned sample data are based upon location and measurement of tiny craters found by electron microscopy of Al foils. Here effects of detection efficiency tail-off at each search magnification can be seen in the down-scale flattening of each scale component, but are reliably compensated by sensible extrapolation between segments. There is also no evidence of malfunction in the operation of DFMI during passage through the coma (S. Green, personal comm.), so can the two data sets be reconciled?

Formation of aluminium nitride and segregation of Cu impurity atoms in aluminium implanted by high dose nitrogen ions

International Nuclear Information System (INIS)

Lin Chenglu; Hemment, P.L.F.; Li Jinhua; Zou Shichang

1994-01-01

Aluminium films with a thickness of 7000 A (containing 0.85% copper) were deposited on silicon substrates. 400 keV N 2 + or 350 keV N + ions were implanted into the aluminium films or at the interface between the aluminium and silicon, respectively. Automatic spreading resistance (ASR), Fourier transform infrared spectroscopy (FTIR) and Rutherford backscattering (RBS) and channelling were used to characterize the formation of aluminium nitride and the depth distribution of the Cu impurity in the aluminium films after ion implantation and post-annealing. The formation of a stoichiometric AlN layer with high resistance was evident from ASR, RBS analysis and FTIR measurements by the presence of the absorption band at 650 cm -1 . When the implanted nitrogen is near the interface between the aluminium and silicon, a multilayer structure can be obtained, which consists of aluminium, aluminium nitride and the silicon substrate. Cu, which is a background impurity in the deposited aluminium films, segregated into the synthesised aluminium nitride during high dose nitrogen ion implantation. This is due to irradiation-induced segregation during ion implantation. (orig.)

Cometary dust: the diversity of primitive refractory grains.

Science.gov (United States)

Wooden, D H; Ishii, H A; Zolensky, M E

2017-07-13

Comet dust is primitive and shows significant diversity. Our knowledge of the properties of primitive cometary particles has expanded significantly through microscale investigations of cosmic dust samples (anhydrous interplanetary dust particles (IDPs), chondritic porous (CP) IDPs and UltraCarbonaceous Antarctic micrometeorites, Stardust and Rosetta ), as well as through remote sensing ( Spitzer IR spectroscopy). Comet dust are aggregate particles of materials unequilibrated at submicrometre scales. We discuss the properties and processes experienced by primitive matter in comets. Primitive particles exhibit a diverse range of: structure and typology; distribution of constituents; concentration and form of carbonaceous and refractory organic matter; Mg- and Fe-contents of the silicate minerals; sulfides; existence/abundance of type II chondrule fragments; high-temperature calcium-aluminium inclusions and ameboid-olivine aggregates; and rarely occurring Mg-carbonates and magnetite, whose explanation requires aqueous alteration on parent bodies. The properties of refractory materials imply there were disc processes that resulted in different comets having particular selections of primitive materials. The diversity of primitive particles has implications for the diversity of materials in the protoplanetary disc present at the time and in the region where the comets formed.This article is part of the themed issue 'Cometary science after Rosetta'. © 2017 The Authors.

Ion nitriding of aluminium

International Nuclear Information System (INIS)

Fitz, T.

2002-09-01

The present study is devoted to the investigation of the mechanism of aluminium nitriding by a technique that employs implantation of low-energy nitrogen ions and diffusional transport of atoms. The nitriding of aluminium is investigated, because this is a method for surface modification of aluminium and has a potential for application in a broad spectrum of fields such as automobile, marine, aviation, space technologies, etc. However, at present nitriding of aluminium does not find any large scale industrial application, due to problems in the formation of stoichiometric aluminium nitride layers with a sufficient thickness and good quality. For the purposes of this study, ion nitriding is chosen, as an ion beam method with the advantage of good and independent control over the process parameters, which thus can be related uniquely to the physical properties of the resulting layers. Moreover, ion nitriding has a close similarity to plasma nitriding and plasma immersion ion implantation, which are methods with a potential for industrial application. (orig.)

Enhanced Saharan dust input to the Levant during Heinrich stadials

Science.gov (United States)

Torfstein, Adi; Goldstein, Steven L.; Stein, Mordechai

2018-04-01

The history of dust transport to the Levant during the last glacial period is reconstructed using the isotope ratios of Pb, Sr, Nd, and Hf in sediments of Lake Lisan, the last glacial Dead Sea. Exposed marginal sections of the Lisan Formation were sampled near Masada, the Perazim Valley and from a core drilled at the deep floor of the modern lake. Bulk samples and size fractions display unique isotopic fingerprints: the finest detritus fraction (<5 μm) displays higher 87Sr/86Sr and lower εNd values (0.710-0.713 and -7.0 to -9.8, respectively) relative to the coarser fractions (5-20 μm and <20 μm; 0.708-0.710 and -3.4 to -8.3) and the bulk detritus samples (0.709-0.711 and -6 to -7.5). Similarly, the 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios (18.26-19.02, 15.634-15.68, and 38.25-38.82, respectively) are systematically higher in the finest detritus fraction relative to corresponding coarser fractions and bulk samples. The 87Sr/86Sr and εNd values of the finest fraction correspond with those of atmospheric dust originating from the Sahara Desert, while those of the coarse fractions are similar to loess deposits exposed in the Sinai and Negev Deserts. Pronounced excursions in the Sr-Nd-Pb isotope ratios toward more Sahara-like values coincide with the Heinrich (H) stadials 6, 5 and 1, reflecting significant increases in Saharan dust fluxes during regionally arid intervals, reflected by sharp lake level drops. Moreover, during H6 the dust came from different Saharan sources than during H1 and H5. While the relatively wet glacial climate in the Levant suppressed the transport of dust to the lake watershed, short-term hyper-arid spells during H-stadial intervals were accompanied by enhanced supply of fine Sahara dust to this region.

Optimisation of the coagulation process of surface water with high content of natural aluminium

Czech Academy of Sciences Publication Activity Database

Tomášková, Hana; Benešová, L.; Pivokonský, Martin

2007-01-01

Roč. 55, č. 3 (2007), s. 199-208 ISSN 0042-790X R&D Projects: GA ČR GA103/07/0295 Institutional research plan: CEZ:AV0Z20600510 Keywords : aluminium fractionation * coagulation * jar test * water treatment Subject RIV: DJ - Water Pollution ; Quality

Variation in aluminium patch test reactivity over time.

Science.gov (United States)

Siemund, Ingrid; Mowitz, Martin; Zimerson, Erik; Bruze, Magnus; Hindsén, Monica

2017-11-01

Contact allergy to aluminium has been reported more frequently in recent years. It has been pointed out that positive patch test reactions to aluminium may not be reproducible on retesting. To investigate possible variations in patch test reactivity to aluminium over time. Twenty-one adults, who had previously reacted positively to aluminium, were patch tested with equimolar dilution series in pet. of aluminium chloride hexahydrate and aluminium lactate, four times over a period of 8 months. Thirty-six of 84 (43%) serial dilution tests with aluminium chloride hexahydrate and 49 of 84 (58%) serial dilution tests with aluminium lactate gave negative results. The range of reactivity varied between a negative reaction to aluminium chloride hexahydrate at 10% and/or to aluminium lactate at 12%, and a positive reaction to aluminium chloride hexahydrate at 0.1% and/or to aluminium lactate at 0.12%. The highest individual difference in test reactivity noticed was 320-fold when the two most divergent minimal eliciting concentrations were compared. The patch test reactivity to aluminium varies over time. Aluminium-allergic individuals may have false-negative reactions. Therefore, retesting with aluminium should be considered when there is a strong suspicion of aluminium contact allergy. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

House dust in seven Danish offices

Science.gov (United States)

Mølhave, L.; Schneider, T.; Kjærgaard, S. K.; Larsen, L.; Norn, S.; Jørgensen, O.

Floor dust from Danish offices was collected and analyzed. The dust was to be used in an exposure experiment. The dust was analyzed to show the composition of the dust which can be a source of airborne dust indoors. About 11 kg of dust from vacuum cleaner bags from seven Danish office buildings with about 1047 occupants (12 751 m 2) was processed according to a standardized procedure yielding 5.5 kg of processed bulk dust. The bulk dust contained 130.000-160.000 CFU g -1 microorganisms and 71.000-90.000 CFU g -1 microfungi. The content of culturable microfungi was 65-123 CFU 30 g -1 dust. The content of endotoxins ranged from 5.06-7.24 EU g -1 (1.45 ng g -1 to 1.01 ng g -1). Allergens (ng g -1) were from 147-159 (Mite), 395-746 (dog) and 103-330 (cat). The macro molecular organic compounds (the MOD-content) varied from 7.8-9.8 mg g -1. The threshold of release of histamine from basophil leukocytes provoked by the bulk dust was between 0.3 and 1.0 mg ml -1. The water content was 2% (WGT) and the organic fraction 33%. 6.5-5.9% (dry) was water soluble. The fiber content was less than 0.2-1.5% (WGT) and the desorbable VOCs was 176-319 μg g -1. Most of the VOC were aldehydes. However, softeners for plastic (DBP and DEHP) were present. The chemical composition includes human and animal skin fragments, paper fibers, glass wool, wood and textilefibers and inorganic and metal particles. The sizes ranged from 0.001-1 mm and the average specific density was 1.0 g m -3. The bulk dust was resuspended and injected into an exposure chamber. The airborne dust was sampled and analyzed to illustrate the exposures that can result from sedimented dirt and dust. The airborne dust resulting from the bulk dust reached concentrations ranging from 0.26-0.75 mg m -3 in average contained 300-170 CFU m -3. The organic fraction was from 55-70% and the water content about 2.5% (WGT). The content of the dust was compared to the similar results reported in the literature and its toxic potency is

Recovery in aluminium

DEFF Research Database (Denmark)

Gundlach, Carsten

2006-01-01

In the present thesis the development of a unique experimental method for volume characterisation of individual embedded crystallites down to a radius of 150 nm is presented. This method is applied to in-situ studies of recovery in aluminium. The method is an extension of 3DXRD microscopy, an X...... are represented as strings. To identify the strings a combination of a 5D connected component type algorithm and multi-peak fitting was found to be superior. The first use of the method was a study of recovery of a deformed aluminium alloy (AA1050). The aluminium alloy was deformed by cold rolling to a thickness...

Ice nucleation properties of mineral dust particles: determination of onset RHi, IN active fraction, nucleation time-lag, and the effect of active sites on contact angles

Directory of Open Access Journals (Sweden)

S. Dobbie

2010-01-01

Full Text Available A newly developed ice nucleation experimental set up was used to investigate the heterogeneous ice nucleation properties of three Saharan and one Spanish dust particle samples. It was observed that the spread in the onset relative humidities with respect to ice (RHi for Saharan dust particles varied from 104% to 110%, whereas for the Spanish dust from 106% to 110%. The elemental composition analysis shows a prominent Ca feature in the Spanish dust sample which could potentially explain the differences in nucleation threshold. Although the spread in the onset RHi for the three Saharan dust samples were in agreement, the active fractions and nucleation time-lags calculated at various temperature and RHi conditions were found to differ. This could be due to the subtle variation in the elemental composition of the dust samples, and surface irregularities like steps, cracks, cavities etc. A combination of classical nucleation theory and active site theory is used to understand the importance of these surface irregularities on the nucleability parameter, contact angle that is widely used in ice cloud modeling. These calculations show that the surface irregularities can reduce the contact angle by approximately 10 degrees.

Internal friction in iron-aluminium alloys having a high aluminium content

International Nuclear Information System (INIS)

Hillairet, J.; Delaplace, J.; Silvent, A.

1966-01-01

By using a torsion pendulum to measure the internal friction of iron-aluminium alloys containing between 25 and 50 atom per cent of aluminium, it has been possible to show the existence of three damping peaks due to interstitial carbon. Their evolution is followed as a function of the carbon content, of the thermal treatment and of the aluminium content. A model based on the preferential occupation of tetrahedral sites is proposed as an interpretation of the results. A study of the Zener peak in these substitution alloys shows also that a part of the short distance disorder existing at high temperatures can be preserved by quenching. (author) [fr

Particle size: a missing factor in risk assessment of human exposure to toxic chemicals in settled indoor dust.

Science.gov (United States)

Cao, Zhi-Guo; Yu, Gang; Chen, Yong-Shan; Cao, Qi-Ming; Fiedler, Heidelore; Deng, Shu-Bo; Huang, Jun; Wang, Bin

2012-11-15

For researches on toxic chemicals in settled indoor dust, selection of dust fraction is a critical influencing factor to the accuracy of human exposure risk assessment results. However, analysis of the selection of dust fraction in recent studies revealed that there is no consensus. This study classified and presented researches on distribution of toxic chemicals according to dust particle size and on relationship between dust particle size and human exposure possibility. According to the literature, beyond the fact that there were no consistent conclusions on particle size distribution of adherent fraction, dust with particle size less than 100 μm should be paid more attention and that larger than 250 μm is neither adherent nor proper for human exposure risk assessment. Calculation results based on literature data show that with different selections of dust fractions, analytical results of toxic chemicals would vary up to 10-fold, which means that selecting dust fractions arbitrarily will lead to large errors in risk assessment of human exposure to toxic chemicals in settled dust. Taking into account the influence of dust particle size on risk assessment of human exposure to toxic chemicals, a new methodology for risk assessment of human exposure to toxic chemicals in settled indoor dust is proposed and human exposure parameter systems to settled indoor dust are advised to be established at national and regional scales all over the world. Copyright © 2012 Elsevier Ltd. All rights reserved.

Migration of Interplanetary Dust and Comets

Science.gov (United States)

Ipatov, S. I.; Mather, J. C.

Our studies of migration of interplanetary dust and comets were based on the results of integration of the orbital evolution of 15,000 dust particles and 30,000 Jupiter-family comets (JFCs) [1-3]. For asteroidal and cometary particles, the values of the ratio β between the radiation pressure force and the gravitational force varied from 1000 and 1 microns. The probability of a collision of a dust particle started from an asteroid or JFC with the Earth during a lifetime of the particle was maximum at diameter d ˜100 microns. For particles started from asteroids and comet 10P, this maximum probability was ˜0.01. Different studies of migration of dust particles and small bodies testify that the fraction of cometary dust particles of the overall dust population inside Saturn's orbit is considerable and can be dominant: (1) Cometary dust particles produced both inside and outside Jupiter's orbit are needed to explain the observed constant number density of dust particles at 3-18 AU. The number density of migrating trans-Neptunian particles near Jupiter's orbit is smaller by a factor of several than that beyond Saturn's orbit. Only a small fraction of asteroidal particles can get outside Jupiter's orbit. (2) Some (less than 0.1%) JFCs can reach typical near-Earth object orbits and remain there for millions of years. Dynamical lifetimes of most of the former JFCs that have typical near-Earth object orbits are about 106 -109 yr, so during most of these times they were extinct comets. Such former comets could disintegrate and produce a lot of mini-comets and dust. (3) Comparison of the velocities of zodiacal dust particles (velocities of MgI line) based on the distributions of particles over their orbital elements obtained in our runs [3-4] with the velocities obtained at the WHAM observations shows that only asteroidal dust particles cannot explain these observations, and particles produced by comets, including high-eccentricity comets, are needed for such explanation

Content and bioaccessibility of aluminium in duplicate diets from southern Spain.

Science.gov (United States)

Cabrera-Vique, Carmen; Mesías, Marta

2013-08-01

Aluminium is found naturally in foods and beverages, but levels increase notably during processing, packaging, storage, and cooking, as a consequence of its presence in food additives and the wide use of aluminium utensils and vessels. Dietary intake of Al was estimated in 2 population groups in southern Spain (families and university students) in a duplicate diet sampling study. Diets were sampled for 7 consecutive days, and Al was determined in acid-mineralized samples with electrothermal atomization-atomic absorption spectrometry (ETA-AAS). Mean values for Al intake were 2.93 and 1.01 mg/d in families and students, respectively, ranging from 0.12 to 10.00 mg/d. Assuming an average adult weight of 60 kg, the mean dietary exposures to aluminium were 0.34 and 0.12 mg/kg body weight/week in these groups, which amounted to 17% and 6% of the 2 mg/kg body weight estimated as the tolerable weekly intake by the Joint FAO/WHO Expert Committee on Food Additives. Bioaccessibility of dietary Al tested with in vitro studies ranged from 0.30 to 17.26% (absorbable fraction). The highest aluminium intakes were observed in subjects consuming diets with a low adherence to the Mediterranean diet, which were associated to high consumption of processed and canned food. On the contrary, subjects consuming diets with a high adherence to the Mediterranean diet patterns showed the lowest Al intakes. The present findings are useful for giving both a reliable estimate of total aluminium dietary intake and tolerable intake levels according to usual dietary habits. © 2013 Institute of Food Technologists®

The determination of trace oxygen in aluminium and aluminium-silicon alloy by helium-3 activation analysis

International Nuclear Information System (INIS)

Vandecasteele, C.; Goethals, P.; Kieffer, R.; Hoste, J.

1975-01-01

The determination of oxygen in aluminium and aluminium-silicon alloy by helium-3 activation is studied. The 18 F formed from oxygen is separated by distillation followed by precipitation of leadfluorochloride. The chemical yield is determined by activation in an isotopic neutron source. Concentrations of resp. 27 and 64 ng.g -1 with a precision for a single determination of resp. 30 and 13% are found in 99.5% aluminium and in aluminium-silicon (3%) alloy. (author)

Aluminium in foodstuffs and diets in Sweden.

Science.gov (United States)

Jorhem, L; Haegglund, G

1992-01-01

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

Short-term variability of mineral dust, metals and carbon emission from road dust resuspension

Science.gov (United States)

Amato, Fulvio; Schaap, Martijn; Denier van der Gon, Hugo A. C.; Pandolfi, Marco; Alastuey, Andrés; Keuken, Menno; Querol, Xavier

2013-08-01

Particulate matter (PM) pollution in cities has severe impact on morbidity and mortality of their population. In these cities, road dust resuspension contributes largely to PM and airborne heavy metals concentrations. However, the short-term variation of emission through resuspension is not well described in the air quality models, hampering a reliable description of air pollution and related health effects. In this study we experimentally show that the emission strength of resuspension varies widely among road dust components/sources. Our results offer the first experimental evidence of different emission rates for mineral dust, heavy metals and carbon fractions due to traffic-induced resuspension. Also, the same component (or source) recovers differently in a road in Barcelona (Spain) and a road in Utrecht (The Netherlands). This finding has important implications on atmospheric pollution modelling, mostly for mineral dust, heavy metals and carbon species. After rain events, recoveries were generally faster in Barcelona rather than in Utrecht. The largest difference was found for the mineral dust (Al, Si, Ca). Tyre wear particles (organic carbon and zinc) recovered faster than other road dust particles in both cities. The source apportionment of road dust mass provides useful information for air quality management.

Constructions of aluminium electrolytic cells

International Nuclear Information System (INIS)

Galushkin, N.V.

1995-01-01

This chapter of monograph is devoted to constructions of aluminium electrolytic cells. Therefore, the general characteristic and classification of aluminium electrolytic cells was considered. The anode and cathode structure was studied. The lining of cathode casing, the process of collection of anode gases, electrolytic cell cover, and electrical insulation was studied as well. The installation and dismantling of aluminium electrolytic cells was described.

The Marriage of Gas and Dust

Science.gov (United States)

Price, D. J.; Laibe, G.

2015-10-01

Dust-gas mixtures are the simplest example of a two fluid mixture. We show that when simulating such mixtures with particles or with particles coupled to grids a problem arises due to the need to resolve a very small length scale when the coupling is strong. Since this is occurs in the limit when the fluids are well coupled, we show how the dust-gas equations can be reformulated to describe a single fluid mixture. The equations are similar to the usual fluid equations supplemented by a diffusion equation for the dust-to-gas ratio or alternatively the dust fraction. This solves a number of numerical problems as well as making the physics clear.

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

Science.gov (United States)

Frankowski, Marcin; Zioła-Frankowska, Anetta; Kurzyca, Iwona; Novotný, Karel; Vaculovič, Tomas; Kanický, Viktor; Siepak, Marcin; Siepak, Jerzy

2011-11-01

The paper presents the results of aluminium determinations in ground water samples of the Miocene aquifer from the area of the city of Poznań (Poland). The determined aluminium content amounted from 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.

[Association between serum aluminium level and methylation of amyloid precursor protein gene in workers engaged in aluminium electrolysis].

Science.gov (United States)

Yang, X J; Yuan, Y Z; Niu, Q

2016-04-20

To investigate the association between serum aluminium level and methylation of the promoter region of amyloid precursor protein (APP)gene in workers engaged in aluminium electrolysis. In 2012, 366 electrolysis workers in an aluminium factory were enrolled as exposure group (working years >10 and age >40 years)and divided into low-exposure group and high-exposure group based on the median serum aluminium level. Meanwhile, 102 workers in a cement plant not exposed to aluminium were enrolled as control group. Graphite furnace atomic absorption spectrometry was used to measure serum aluminium level, methylation specific PCR was used to measure the methylation rate of the promoter region of APP gene, and ELI-SA was used to measure the protein expression of APP in lymphocytes in peripheral blood. The exposure group had a significantly higher serum aluminium level than the control group (45.07 μg/L vs 30.51 μg/L, P0.05). The multivariate logistic regression analysis showed that with reference to the control group, low aluminium exposure (OR=1.86, 95% CI 1.67~3.52)and high aluminium exposure (OR=2.98, 95% CI 1.97~4.15)were risk factors for a reduced methylation rate of the promoter region of APP gene. Reduced methylation of the promoter region of APP gene may be associated with increased serum aluminium level, and downregulated methylation of the promoter region of APP gene may accelerate APP gene transcription.

Parameterizing the interstellar dust temperature

Science.gov (United States)

Hocuk, S.; Szűcs, L.; Caselli, P.; Cazaux, S.; Spaans, M.; Esplugues, G. B.

2017-08-01

The temperature of interstellar dust particles is of great importance to astronomers. It plays a crucial role in the thermodynamics of interstellar clouds, because of the gas-dust collisional coupling. It is also a key parameter in astrochemical studies that governs the rate at which molecules form on dust. In 3D (magneto)hydrodynamic simulations often a simple expression for the dust temperature is adopted, because of computational constraints, while astrochemical modelers tend to keep the dust temperature constant over a large range of parameter space. Our aim is to provide an easy-to-use parametric expression for the dust temperature as a function of visual extinction (AV) and to shed light on the critical dependencies of the dust temperature on the grain composition. We obtain an expression for the dust temperature by semi-analytically solving the dust thermal balance for different types of grains and compare to a collection of recent observational measurements. We also explore the effect of ices on the dust temperature. Our results show that a mixed carbonaceous-silicate type dust with a high carbon volume fraction matches the observations best. We find that ice formation allows the dust to be warmer by up to 15% at high optical depths (AV> 20 mag) in the interstellar medium. Our parametric expression for the dust temperature is presented as Td = [ 11 + 5.7 × tanh(0.61 - log 10(AV) ]χuv1/5.9, where χuv is in units of the Draine (1978, ApJS, 36, 595) UV field.

Bumblebee pupae contain high levels of aluminium.

Science.gov (United States)

Exley, Christopher; Rotheray, Ellen; Goulson, David

2015-01-01

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

Soil or Dust for Health Risk Assessment Studies in Urban Environment.

Science.gov (United States)

Gabarrón, M; Faz, A; Acosta, J A

2017-10-01

To identify the best material (soil or dust) to be selected for health-risk assessment studies, road dust and urban soil from three cities with different population densities were collected, and size fractions were analysed for metal content (Pb, Zn, Cu, Cd, Cr, Co, and Ni). Results showed similar distribution of the size particles among cities, predominating fractions between 75 and 2000 μm in road dust and particles below 75 μm in soil. Metals were mainly bound to PM10 in both soil and road dust increasing the risk of adverse health effects, overall through inhalation exposure. The risk assessment showed that the most hazardous exposure pathway was the ingestion via, followed by dermal absorption and inhalation route. Values of hazard quotient showed that the risk for children due to the ingestion and dermal absorption was higher than adults, and slightly larger at PM10 comparing to <75-μm fraction for the inhalation route. Higher risk values were found for road dust, although any hazard index or cancer risk index value did not overreach the safe value of 10 -6 .

Dust from southern Africa: rates of emission and biogeochemical properties

Science.gov (United States)

Bhattachan, A.; D'Odorico, P.; Zobeck, T. M.; Okin, G. S.; Dintwe, K.

2012-12-01

The stabilized linear dunefields in the southern Kalahari show signs of reactivation due to reduced vegetation cover owing to drought and/or overgrazing. It has been demonstrated with a laboratory dust generator that the southern Kalahari soils are good emitters of dust and that large-scale dune reactivation can potentially make the region an important dust source in the relatively low-dust Southern Hemisphere. We show that emergence of the southern Kalahari as a new dust source may affect ocean biogeochemistry as the soils are rich in soluble iron and the dust from the southern Kalahari commonly reaches the Southern Ocean. We investigate the biogeochemical properties of the fine fraction of soil from the Kalahari dunes and compare them to those of currently active dust sources such as the Makgadikgadi and the Etosha pans as well as other smaller pans in the region. Using field measurements of sediment fluxes and satellite images, we calculate the rates of dust emission from the southern Kalahari under different land cover scenarios. To assess the reversibility of dune reactivation in the southern Kalahari, we investigate the resilience of dunefield vegetation by looking at changes in soil nutrients, fine soil fractions, and seed bank in areas affected by intense denudation.

Design and analysis of aluminium brdiges

NARCIS (Netherlands)

Soetens, F.; Straalen, IJ.J. van

2004-01-01

Applications of aluminium have grown considerably in building and civil engineering the last decade, which is due to various aspects: light weight, durability and maintenance, use of extrusions. The paper starts with a short history of aluminium bridges and then focuses on aluminium bridges in the

Recycling of aluminium swarf by direct incorporation in aluminium melts

OpenAIRE

Puga, Hélder; Barbosa, J.; Soares, Delfim; Silva, Filipe Samuel; Ribeiro, Carlos Silva

2009-01-01

The purpose of this work was to recover a standard AlSi12Cu1 alloy from machining chips inside the foundry plant, by using an environmentally friend technique to produce cast ingots with characteristics similar to those of the commercially available 2nd melt raw material. The recyclability of aluminium swarf using different melting techniques and the influence of chips preparation in the aluminium alloy recovery rate and dross production was experimentally studied and evaluated...

EXPERIMENTAL INVESTIGATION OF IRRADIATION-DRIVEN HYDROGEN ISOTOPE FRACTIONATION IN ANALOGS OF PROTOPLANETARY HYDROUS SILICATE DUST

Energy Technology Data Exchange (ETDEWEB)

Roskosz, Mathieu; Remusat, Laurent [IMPMC, CNRS UMR 7590, Sorbonne Universités, Université Pierre et Marie Curie, IRD, Muséum National d’Histoire Naturelle, CP 52, 57 rue Cuvier, Paris F-75231 (France); Laurent, Boris; Leroux, Hugues, E-mail: mathieu.roskosz@mnhn.fr [Unité Matériaux et Transformations, Université Lille 1, CNRS UMR 8207, Bâtiment C6, F-59655 Villeneuve d’Ascq (France)

2016-11-20

The origin of hydrogen in chondritic components is poorly understood. Their isotopic composition is heavier than the solar nebula gas. In addition, in most meteorites, hydrous silicates are found to be lighter than the coexisting organic matter. Ionizing irradiation recently emerged as an efficient hydrogen fractionating process in organics, but its effect on H-bearing silicates remains essentially unknown. We report the evolution of the D/H of hydrous silicates experimentally irradiated by electrons. Thin films of amorphous silica, amorphous “serpentine,” and pellets of crystalline muscovite were irradiated at 4 and 30 keV. For all samples, irradiation leads to a large hydrogen loss correlated with a moderate deuterium enrichment of the solid residue. The entire data set can be described by a Rayleigh distillation. The calculated fractionation factor is consistent with a kinetically controlled fractionation during the loss of hydrogen. Furthermore, for a given ionizing condition, the deuteration of the silicate residues is much lower than the deuteration measured on irradiated organic macromolecules. These results provide firm evidence of the limitations of ionizing irradiation as a driving mechanism for D-enrichment of silicate materials. The isotopic composition of the silicate dust cannot rise from a protosolar to a chondritic signature during solar irradiations. More importantly, these results imply that irradiation of the disk naturally induces a strong decoupling of the isotopic signatures of coexisting organics and silicates. This decoupling is consistent with the systematic difference observed between the heavy organic matter and the lighter water typically associated with minerals in the matrix of most carbonaceous chondrites.

Irradiation damage in aluminium single crystals produced by 50-keV aluminium and copper ions

DEFF Research Database (Denmark)

Henriksen, L.; Johansen, A.; Koch, J.

1968-01-01

Aluminium single crystals, thin enough to be examined by electron microscopy, have been irradiated with 50-keV aluminium and copper ions. The irradiation fluxes were in the range 1011–1014 cm−2 s−1 and the doses were from 6 × 1012 to 6 × 1014 cm−2. Irradiation along either a or a direction produces...... rows of dislocation loops all lying parallel to one particular direction. If the aluminium target is quenched from 600 °C and annealed at room temperature prior to irradiation with aluminium ions, the rows of loops are suppressed. The amount of damage observed is considerably less than would...

Creation of Wood Dust during Wood Processing: Size Analysis, Dust Separation, and Occupational Health

Directory of Open Access Journals (Sweden)

Eva Mračková

2015-11-01

Full Text Available Mechanical separators and fabric filters are being used to remove airborne fine particles generated during the processing and handling of wood. Such particles might have a harmful effect on employee health, not only in small- but also in large-scale wood processing facilities. The amount of wood dust and its dispersion conditions vary according to geometric boundary conditions. Thus, the dispersion conditions could be changed by changing the linear size of the particles. Moreover, the smaller the particles are, the more harmful they can be. It is necessary to become familiar with properties, from a health point of view, of wood dust generated from processing. Wood dust has to be sucked away from the processing area. The fractional separation efficiency of wood dust can be improved using exhaust and filtering devices. Filtration efficiency depends on moisture content, particle size, and device performance. Because of the carcinogenicity of wood dust, the concentration of wood dust in air has to be monitored regularly. Based on the results hereof, a conclusion can be made that both mechanical separators of types SEA and SEB as well as the fabric filters with FINET PES 1 textile are suitable for the separation of wet saw dust from all types of wooden waste produced within the process.

Laser welding of aluminium alloys

OpenAIRE

Forsman, Tomas

2000-01-01

This thesis treats laser welding of aluminium alloys from a practical perspective with elements of mathematical analysis. The theoretical work has in all cases been verified experimentally. The aluminium alloys studied are from the 5xxx and 6xxx groups which are common for example in the automotive industry. Aluminium has many unique physical properties. The properties which more than others have been shown to influence the welding process is its high reflection, high thermal conductivity, lo...

Ice Nucleating Particle Properties in the Saharan Air Layer Close to the Dust Source

Science.gov (United States)

Boose, Y.; Garcia, I. M.; Rodríguez, S.; Linke, C.; Schnaiter, M.; Nickovic, S.; Lohmann, U.; Kanji, Z. A.; Sierau, B.

2015-12-01

In August 2013 and 2014 measurements of ice nucleating particle (INP) concentrations, aerosol particle size distributions, chemistry and fluorescence were conducted at the Izaña Atmospheric Observatory located at 2373 m asl on Tenerife, west off the African shore. During summer, the observatory is frequently within the Saharan Air Layer and thus often exposed to dust. Absolute INP concentrations and activated fractions at T=-40 to -15°C and RHi=100-150 % were measured. In this study, we discuss the in-situ measured INP properties with respect to changes in the chemical composition, the biological content, the source regions as well as transport pathways and thus aging processes of the dust aerosol. For the first time, ice crystal residues were also analyzed with regard to biological content by means of their autofluorescence signal close to a major dust source region. Airborne dust samples were collected with a cyclone for additional offline analysis in the laboratory under similar conditions as in the field. Both, in-situ and offline dust samples were chemically characterized using single-particle mass spectrometry. The DREAM8 dust model extended with dust mineral fractions was run to simulate meteorological and dust aerosol conditions for ice nucleation. Results show that the background aerosol at Izaña was dominated by carbonaceous particles, which were hardly ice-active under the investigated conditions. When Saharan dust was present, INP concentrations increased by up to two orders of magnitude even at water subsaturated conditions at T≤-25°C. Differences in the ice-activated fraction were found between different dust periods which seem to be linked to variations in the aerosol chemical composition (dust mixed with changing fractions of sea salt and differences in the dust aerosol itself). Furthermore, two biomass burning events in 2014 were identified which led to very low INP concentrations under the investigated temperature and relative humidity

The Spatial Variation of Dust Particulate Matter Concentrations during Two Icelandic Dust Storms in 2015

Directory of Open Access Journals (Sweden)

Pavla Dagsson-Waldhauserova

2016-06-01

Full Text Available Particulate matter mass concentrations and size fractions of PM1, PM2.5, PM4, PM10, and PM15 measured in transversal horizontal profile of two dust storms in southwestern Iceland are presented. Images from a camera network were used to estimate the visibility and spatial extent of measured dust events. Numerical simulations were used to calculate the total dust flux from the sources as 180,000 and 280,000 tons for each storm. The mean PM15 concentrations inside of the dust plumes varied from 10 to 1600 µg·m−3 (PM10 = 7 to 583 µg·m−3. The mean PM1 concentrations were 97–241 µg·m−3 with a maximum of 261 µg·m−3 for the first storm. The PM1/PM2.5 ratios of >0.9 and PM1/PM10 ratios of 0.34–0.63 show that suspension of volcanic materials in Iceland causes air pollution with extremely high PM1 concentrations, similar to polluted urban areas in Europe or Asia. Icelandic volcanic dust consists of a higher proportion of submicron particles compared to crustal dust. Both dust storms occurred in relatively densely inhabited areas of Iceland. First results on size partitioning of Icelandic dust presented here should challenge health authorities to enhance research in relation to dust and shows the need for public dust warning systems.

Composite grains: Application to circumstellar dust

Directory of Open Access Journals (Sweden)

D. B. Vaidya

2011-09-01

Full Text Available Using the discrete dipole approximation (DDA we calculate the absorption efficiency of the composite grain, made up of a host silicate spheroid and inclusions of graphite, in the spectral region 5.0-25.0μm. We study the absorption as a function of the voulume fraction of the inclusions. In particular, we study the variation in the 10.0μm and 18.0μm emission features with the volume fraction of the inclusions. Using the extinction efficiencies, of the composite grains we calculate the infrared fluxes at several dust temperatures and compare the model curves with the observed infrared emission curves (IRAS-LRS, obtained for circumstellar dust shells around oxygen rich M-type stars.

Developments in the US aluminium recycling industry

Energy Technology Data Exchange (ETDEWEB)

Bolling, R N

1983-06-01

In the USA scrap recovery of aluminium has gained in importance since the war. Today its amounts to about 32% of total supply. On the other hand primary production in the US seems to have hardly any expansion possibilities. The development of the aluminium beverage can is the clearest example for recycling growth. The increased use of aluminium in passenger cars has led to very close technical and local relations of aluminium foundries and secondary smelters. The changing nature of the aluminium business caused by the growth of recycling should be recognized and made use of.

Process for the manufacture of plates containing neutron poison from aluminium and aluminium alloys

International Nuclear Information System (INIS)

Bauer, G.; Pollmann, E.; Srostlik, P.

1985-01-01

A process for guaranteeing sub-critical arrangements of nuclear fuel in tranport and/or storage containers is described, in which a homogeneous distribution of neutron poison in the aluminium matrix is guaranteed. A homogeneous mixture of aluminium powder and neutron poison powder is produced, this is pressed into plates in several stages, dried and made into hollow aluminium profiles of rectangular cross-section. The open ends of the hollow profile are then closed and this is rolled to the required dimension at 470-500 0 C. (orig./HP) [de

Chapter 1. Economic aspects of aluminium production

International Nuclear Information System (INIS)

Yanko, E.A.; Kabirov, Sh.O.; Safiev, Kh.; Azizov, B.S.; Mirpochaev, Kh.A.

2011-01-01

This article is devoted to economic aspects of aluminium production. Therefore, the perspectives of development of aluminium production, the base components of aluminium cost and economic security of enterprise are considered in this chapter.

Aluminium and nickel in human albumin solutions

DEFF Research Database (Denmark)

Gammelgaard, Bente; Sandberg, E

1989-01-01

Five different brands of commercially available human albumin solutions for infusion were analysed for their aluminium and nickel contents by atomic absorption spectrometry. The aluminium concentrations ranged from 12 micrograms/l to 1109 micrograms/l and the nickel concentrations ranged from 17...... micrograms/l to 77 micrograms/l. Examination of the aluminium and nickel contents of the constituents for the production of one brand showed too low levels to explain the final contamination of the product. By following the aluminium and nickel concentrations of the same brand during the production...... of a batch of albumin solution, filtration was shown to contribute to contamination, although the largest increase in aluminium as well as nickel concentrations appeared during the bulk concentrating process. To avoid health risks to certain patients, regulations should be established requiring aluminium...

ON THE REDSHIFT EVOLUTION OF THE Lyα ESCAPE FRACTION AND THE DUST CONTENT OF GALAXIES

International Nuclear Information System (INIS)

Hayes, Matthew; Schaerer, Daniel; Oestlin, Goeran; Mas-Hesse, J. Miguel; Atek, Hakim; Kunth, Daniel

2011-01-01

The Lyα emission line has been proven to be a powerful tool for studying evolving galaxies at the highest redshift. However, in order to use Lyα as a physical probe of galaxies, it becomes vital to know the Lyα escape fraction (f Lyα esc ). Unfortunately, due to the resonant nature of Lyα, f Lyα esc may vary unpredictably and requires empirical measurement. Here, we compile Lyα luminosity functions (LFs) between redshifts z = 0 and 8 and, combined with Hα and ultraviolet data, assess how f Lyα esc evolves with redshift. We find a strong upward evolution in f Lyα esc over the range z = 0.3-6, which is well fit by the power law f Lyα esc ∝(1 + z) ξ with ξ = (2.57 +0.19 -0.12 ). This predicts that f Lyα esc should reach unity at z = 11.1. By comparing f Lyα esc and E B-V in individual galaxies we derive an empirical relationship between f Lyα esc and E B-V , which includes resonance scattering and can explain the redshift evolution of f Lyα esc between z = 0 and 6 purely as a function of the evolution in the dust content of galaxies. Beyond z ∼ 6.5, f Lyα esc drops more substantially, an effect attributed to either ionizing photon leakage, or an increase in the neutral gas fraction of the intergalactic medium. While distinguishing between these two scenarios may be extremely challenging, by framing the problem this way we remove the uncertainty of the halo mass from Lyα-based tests of reionization. We finally derive a new method by which to estimate the dust content of galaxies, based purely upon the observed Lyα and UV LFs. These data are characterized by an exponential with an e-folding scale of z EBV ∼ 3.4.

Aluminium beverage can recycling

Energy Technology Data Exchange (ETDEWEB)

Lewinski, A von

1985-08-01

Canned beverages have become a controversial issue in this era of ecological sensitivity. METALL has already discussed the problem of can recycling. The present article discusses the technical aspects of aluminium can recycling. Two further articles will follow on aluminium can recycling in North America and on the results of European pilot projects.

Experimental investigations on a CRDI system assisted diesel engine fuelled with aluminium oxide nanoparticles blended biodiesel

Directory of Open Access Journals (Sweden)

C. Syed Aalam

2015-09-01

Full Text Available Experiments were conducted to determine engine performance, exhaust emissions and combustion characteristics of a single cylinder, common rail direct injection (CRDI system assisted diesel engine using diesel with 25 percentage of zizipus jujube methyl ester blended fuel (ZJME25. Along with this ZJME25 aluminium oxide nanoparticles were added as additive in mass fractions of 25 ppm (AONP 25 and 50 ppm (AONP 50 with the help of a mechanical Homogenizer and an ultrasonicator. It was observed that aluminium oxide nanoparticles blended fuel exhibits a significant reduction in specific fuel consumption and exhaust emissions at all operating loads. At the full load, the magnitude of HC and smoke emission for the ZJME25 before the addition of aluminium oxide nanoparticles was 13.459 g/kW h and 79 HSU, whereas it was 8.599 g/kW h and 49 HSU for the AONP 50 blended ZJME25 fuel respectively. The results also showed a considerable enhancement in brake thermal efficiency and heat release rate due to the influence of aluminium oxide nanoparticles addition in biodiesel–diesel blend.

Photochemical preparation of aluminium oxide layers via vacuum ultraviolet irradiation of a polymeric hexanoato aluminium complex

International Nuclear Information System (INIS)

Wennrich, L.; Khalil, H.; Bundesmann, C.; Decker, U.; Gerlach, J.W.; Helmstedt, U.; Manova, D.; Naumov, S.; Prager, L.

2013-01-01

By means of photochemical conversion of thin layers of a polymeric hexanoato aluminium complex as the precursor, thin aluminium oxide layers were prepared onto silicon wafers. The precursor compound was synthesized and characterized by several analytical techniques like NMR, FTIR, XPS, ICP, and found to be a polymeric aluminium-containing coordination compound which has been proposed to be a hydroxo-bridged aluminium chain with pendant hexanoyl side-chains ascertained as catena-poly[{di(κ-O,O-hexanoato)aluminium}(μ-hydroxo)] (PHAH). Thin layers deposited from a solution of PHAH in toluene onto silicon wafers were irradiated using VUV radiation from a xenon excimer lamp. The layers were characterized by XPS, XRD, XRR, and spectroscopic ellipsometry. VUV radiation with a radiant exposure of E = 36 J cm −2 led to almost carbon-free amorphous layers with a composition close to that of alumina having a density of about 2.1 g cm −3 . Thus, using the example of a polymeric aluminium complex, the potential of the photochemical conversion of metal complexes into oxides could be shown as an alternative method, in addition to sol–gel techniques, for the generation of thin plane metal-oxide layers at normal temperature and pressure. Highlights: ► A polymeric aluminium complex was synthesized and characterized by NMR, FTIR, XPS and ICP. ► Thin layers of the compound were irradiated using vacuum-UV radiation and converted to AlO x . ► Quantum-chemical calculations explain the conversion mechanism.

Aluminium-27 n.m.r. studies of aluminium fluoro complexes in dichloromethane solution: evidence for tetrafluoroaluminate anion

International Nuclear Information System (INIS)

Colton, R.; Eller, P.G.

1989-01-01

Mixed aluminium chloro/fluoro anions are formed in dichloromethane solution by the interaction of AlCl 3 and [Ph 3 PhCH 2 P] [H 2 F 3 ]. Aluminium-27 n.m.r. studies are restricted to the stoichiometric ranges F/Al from 1:1 to 3:1 and F/Al>8:1. Between these limits rapid precipitation reactions occur. In the fluoride-rich stoichiometric range there is rapid exchange on the n.m.r. time scale between the aluminium fluoro anion and free fluoride, so that a direct identification of the species by the multiplicity of the resonance is not possible. Indirect evidence strongly suggests that the aluminium species is [AlF 4 ] - . In the F/Al stoichiometry range from 1:1 to 3:1 aluminium-27 resonances were observed for all the other possible [AlCl χ F 4-χ ] - species. Studies on the aluminium iodo/fluoro system support the identification of [AlF 4 ] - , but the system is labile and the mixed iodo/fluoro species undergo rapid disproportionation. 12 refs., 1 fig

Effect of hydrogen on aluminium and aluminium alloys: A review

DEFF Research Database (Denmark)

Ambat, Rajan; Dwarakadasa, E.S.

1996-01-01

Susceptibility of aluminium and its alloys towards hydrogen embrittlement has been well established. Still a lot of confusion exists on the question of transport of hydrogen and its possible role in stress corrosion cracking. This paper reviews some of the fundamental properties of hydrogen...... in aluminium and its alloys and its effect on mechanical properties. The importance of hydrogen embrittlement over anodic dissolution to explain the stress corrosion cracking mechanism of these alloys is also examined in considerable detail. The various experimental findings concerning the link between...

Heavy metals in the finest size fractions of road-deposited sediments.

Science.gov (United States)

Lanzerstorfer, Christof

2018-08-01

The concentration of heavy metals in urban road-deposited sediments (RDS) can be used as an indicator for environmental pollution. Thus, their occurrence has been studied in whole road dust samples as well as in size fractions obtained by sieving. Because of the limitations of size separation by sieving little information is available about heavy metal concentrations in the road dust size fractions heavy metals concentrations and size distribution. According to the Geoaccumulation Index the pollution of the road dust samples deceased in the following order: Sb » As > Cu ≈ Zn > Cr > Cd ≈ Pb ≈ Mn > Ni > Co ≈ V. For all heavy metals the concentration was higher in the fine size fractions compared to the coarse size fractions, while the concentration of Sr was size-independent. The enrichment of the heavy metals in the finest size fraction compared to the whole RDS  Sb > (Cu) ≈ Zn ≈ Pb > As ≈ V » Mn. The approximation of the size dependence of the concentration as a function of the particle size by power functions worked very well. The correlation between particle size and concentration was high for all heavy metals. The increased heavy metals concentrations in the finest size fractions should be considered in the evaluation of the contribution of road dust re-suspension to the heavy metal contamination of atmospheric dust. Thereby, power functions can be used to describe the size dependence of the concentration. Copyright © 2018 Elsevier Ltd. All rights reserved.

Raw materials for aluminium production

International Nuclear Information System (INIS)

Galushkin, N.V.

1995-01-01

This chapter of monograph is devoted to to raw materials which used in aluminium production. Therefore, the using of alumina, and fluoride salts in aluminium production was considered. The physical properties of alumina were studied.

Concentration of the genera Aspergillus, Eurotium and Penicillium in 63-μm house dust fraction as a method to predict hidden moisture damage in homes

Directory of Open Access Journals (Sweden)

Assadian Ojan

2009-07-01

Full Text Available Abstract Background Quantitative measurements of mould enrichment of indoor air or house dust might be suitable surrogates to evaluate present but hidden moisture damage. Our intent was to develop a house-dust monitoring method to detect hidden moisture damage excluding the influence of outdoor air, accumulated old dust, and dust swirled up from room surfaces. Methods Based on standardized measurement of mould spores in the 63-μm fraction of house dust yielded by carpets, the background concentrations were determined and compared to simultaneously obtained colony numbers and total spore numbers of the indoor air in 80 non-mouldy living areas during summer and winter periods. Additionally, sampling with a vacuum-cleaner or manual sieve was compared to sampling with a filter holder or sieving machine, and the evaluative power of an established two-step assessment model (lower and upper limits was compared to that of a one-step model (one limit in order to derive concentration limits for mould load in house dust. Results Comparison with existing evaluation procedures proved the developed method to be the most reliable means of evaluating hidden moisture damage, yielding the lowest false-positive results (specificity 98.7%. Background measurements and measurements in 14 mouldy rooms show that even by evaluating just the indicator genera in summer and winter, a relatively certain assessment of mould infestation is possible. Conclusion A one-step evaluation is finally possible for house dust. The house-dust evaluation method is based on analysis of the indicator genera Aspergillus, Eurotium and Penicillium spp., which depend on the total fungal count. Inclusion of further moisture indicators currently appears questionable, because of outdoor air influence and the paucity of measurements.

Electron beam welding of aluminium components

International Nuclear Information System (INIS)

Maajid, Ali; Vadali, S.K.; Maury, D.K.

2015-01-01

Aluminium is one of the most widely used materials in industries like transportation, shipbuilding, manufacturing, aerospace, nuclear, etc. The challenges in joining of aluminium are distortion, cleanliness and quality. Main difficulties faced during fusion welding of aluminium components are removal of surface oxide layer, weld porosity, high heat input requirement, distortion, hot cracking, etc. Physical properties of aluminium such as its high thermal conductivity, high coefficient of thermal expansion, no change in colour at high temperature, large difference in the melting points of the metal and its oxide (∼ 1400 °C) compound the difficulties faced during welding. Gas Tungsten Arc Welding (GTAW), Gas Metal Arc Welding (GMAW), Plasma Arc Welding (PAW), etc are generally used in industries for fusion welding of aluminium alloys. However in case of thicker jobs the above processes are not suitable due to requirements of elaborate edge preparation, preheating of jobs, fixturing to prevent distortion, etc. Moreover, precise control over the heat input during welding and weld bead penetration is not possible with above processes. Further, if heat sensitive parts are located near the weld joint then high energy density beam welding process like Electron Beam Welding (EBW) is the best possible choice for aluminium welding.This paper discusses EB welding of aluminium components, typical geometry of components, selection/optimization of welding parameters, problems faced during standardization of welding and process parameters and their remedies etc.

Solar-Panel Dust Accumulation and Cleanings

Science.gov (United States)

2005-01-01

Air-fall dust accumulates on the solar panels of NASA's Mars Exploration Rovers, reducing the amount of sunlight reaching the solar arrays. Pre-launch models predicted steady dust accumulation. However, the rovers have been blessed with occasional wind events that clear significant amounts of dust from the solar panels. This graph shows the effects of those panel-cleaning events on the amount of electricity generated by Spirit's solar panels. The horizontal scale is the number of Martian days (sols) after Spirit's Jan. 4, 2005, (Universal Time) landing on Mars. The vertical scale indicates output from the rover's solar panels as a fraction of the amount produced when the clean panels first opened. Note that the gradual declines are interrupted by occasional sharp increases, such as a dust-cleaning event on sol 420.

Chapter 2. Theoretical aspects of aluminium production

International Nuclear Information System (INIS)

Yanko, E.A.; Kabirov, Sh.O.; Safiev, Kh.; Azizov, B.S.; Mirpochaev, Kh.A.

2011-01-01

This article is devoted to theoretical aspects of aluminium production. Thus, the electrochemistry of electrolysis process, calculation of base industrial indicators of aluminium electrolytic cell, and processes occurring on anode and cathode were considered. Factors, which increase the current output and electrolytic cell productivity were studied. The side effects, including anode effect, sodium extraction on cathode, aluminium dissolution in the electrolyte, aluminium carbide formation, and influence of admixtures in the electrolyte were studied as well.

Aluminium in brain tissue in familial Alzheimer's disease.

Science.gov (United States)

Mirza, Ambreen; King, Andrew; Troakes, Claire; Exley, Christopher

2017-03-01

The genetic predispositions which describe a diagnosis of familial Alzheimer's disease can be considered as cornerstones of the amyloid cascade hypothesis. Essentially they place the expression and metabolism of the amyloid precursor protein as the main tenet of disease aetiology. However, we do not know the cause of Alzheimer's disease and environmental factors may yet be shown to contribute towards its onset and progression. One such environmental factor is human exposure to aluminium and aluminium has been shown to be present in brain tissue in sporadic Alzheimer's disease. We have made the first ever measurements of aluminium in brain tissue from 12 donors diagnosed with familial Alzheimer's disease. The concentrations of aluminium were extremely high, for example, there were values in excess of 10μg/g tissue dry wt. in 5 of the 12 individuals. Overall, the concentrations were higher than all previous measurements of brain aluminium except cases of known aluminium-induced encephalopathy. We have supported our quantitative analyses using a novel method of aluminium-selective fluorescence microscopy to visualise aluminium in all lobes of every brain investigated. The unique quantitative data and the stunning images of aluminium in familial Alzheimer's disease brain tissue raise the spectre of aluminium's role in this devastating disease. Copyright © 2016 The Authors. Published by Elsevier GmbH.. All rights reserved.

Recent developments in advanced aircraft aluminium alloys

International Nuclear Information System (INIS)

Dursun, Tolga; Soutis, Costas

2014-01-01

Highlights: • To compete with composites, performance of aluminium alloys should be increased. • Al–Li alloys have higher strength, fracture and fatigue/corrosion resistance. • Improvements of aerospace Al alloys are due to optimised solute content and ratios. • In selecting new materials, there should be no reduction in the level of safety. • The use of hybrid materials could provide additional opportunities for Al alloys. - Abstract: Aluminium alloys have been the primary material for the structural parts of aircraft for more than 80 years because of their well known performance, well established design methods, manufacturing and reliable inspection techniques. Nearly for a decade composites have started to be used more widely in large commercial jet airliners for the fuselage, wing as well as other structural components in place of aluminium alloys due their high specific properties, reduced weight, fatigue performance and corrosion resistance. Although the increased use of composite materials reduced the role of aluminium up to some extent, high strength aluminium alloys remain important in airframe construction. Aluminium is a relatively low cost, light weight metal that can be heat treated and loaded to relatively high level of stresses, and it is one of the most easily produced of the high performance materials, which results in lower manufacturing and maintenance costs. There have been important recent advances in aluminium aircraft alloys that can effectively compete with modern composite materials. This study covers latest developments in enhanced mechanical properties of aluminium alloys, and high performance joining techniques. The mechanical properties on newly developed 2000, 7000 series aluminium alloys and new generation Al–Li alloys are compared with the traditional aluminium alloys. The advantages and disadvantages of the joining methods, laser beam welding and friction stir welding, are also discussed

Phthalate and PAH concentrations in dust collected from Danish homes and daycare centers

DEFF Research Database (Denmark)

Langer, Sarka; Weschler, Charles J.; Fischer, Andreas

2010-01-01

(diethyl phthalate (DEP), di(n-butyl) phthalate (DnBP), di(isobutyl) phthalate (DiBP), butyl benzyl phthalate (BBzP), di(2-ethylhexyl) phthalate (DEHP)) and three PAHs (pyrene, benz[a]anthracene (B[a]A) and benzo[a]pyrene (B[a]P)). The three PAHs and DEHP were detected in dust samples from all sites, while...... DEP. DnBP, DiBP and BBzP were detected in more than 75% of the bedrooms and more than 90% of the daycare centers. The dust mass-fractions of both phthalates and PAHs were log-normally distributed. With the exception of DEP, the mass-fractions of phthalates in dust were higher in daycare centers than...... homes: PAH mass-fractions in dust were similar in the two locations. There was no correlation among the different phthalates in either homes or daycare centers. In contrast, the PAH were correlated with one another more strongly so in homes (R-2 = 0.80-0.90) than in daycare centers (R-2 = 0...

THE DUST BUDGET OF THE SMALL MAGELLANIC CLOUD: ARE ASYMPTOTIC GIANT BRANCH STARS THE PRIMARY DUST SOURCE AT LOW METALLICITY?

International Nuclear Information System (INIS)

Boyer, M. L.; Gordon, K. D.; Meixner, M.; Sargent, B. A.; Srinivasan, S.; Riebel, D.; McDonald, I.; Van Loon, J. Th.; Clayton, G. C.; Sloan, G. C.

2012-01-01

We estimate the total dust input from the cool evolved stars in the Small Magellanic Cloud, using the 8 μm excess emission as a proxy for the dust-production rate (DPR). We find that asymptotic giant branch (AGB) and red supergiant (RSG) stars produce (8.6-9.5) × 10 –7 M ☉ yr –1 of dust, depending on the fraction of far-infrared sources that belong to the evolved star population (with 10%-50% uncertainty in individual DPRs). RSGs contribute the least ( –3 M ☉ of dust each, then the total SN dust input and AGB input are roughly equivalent. We consider several scenarios of SN dust production and destruction and find that the interstellar medium (ISM) dust can be accounted for solely by stellar sources if all SNe produce dust in the quantities seen around the dustiest examples and if most SNe explode in dense regions where much of the ISM dust is shielded from the shocks. We find that AGB stars contribute only 2.1% of the ISM dust. Without a net positive contribution from SNe to the dust budget, this suggests that dust must grow in the ISM or be formed by another unknown mechanism.

Lactobacillus plantarum CCFM639 alleviates aluminium toxicity.

Science.gov (United States)

Yu, Leilei; Zhai, Qixiao; Liu, Xiaoming; Wang, Gang; Zhang, Qiuxiang; Zhao, Jianxin; Narbad, Arjan; Zhang, Hao; Tian, Fengwei; Chen, Wei

2016-02-01

Aluminium (Al) is the most abundant metal in the earth's crust. Al exposure can cause a variety of adverse physiological effects in humans and animals. Our aim was to demonstrate that specific probiotic bacteria can play a special physiologically functional role in protection against Al toxicity in mice. Thirty strains of lactic acid bacteria (LAB) were tested for their aluminium-binding ability, aluminium tolerance, their antioxidative capacity, and their ability to survive the exposure to artificial gastrointestinal (GI) juices. Lactobacillus plantarum CCFM639 was selected for animal experiments because of its excellent performance in vitro. Forty mice were divided into four groups: control, Al only, Al plus CCFM639, and Al plus deferiprone (DFP). CCFM639 was administered at 10(9) CFU once daily for 10 days, followed by a single oral dose of aluminium chloride hexahydrate at 5.14 mg aluminium (LD50) for each mouse. The results showed that CCFM639 treatment led to a significant reduction in the mortality rates with corresponding decrease in intestinal aluminium absorption and in accumulation of aluminium in the tissues and amelioration of hepatic histopathological damage. This probiotic treatment also resulted in alleviation of hepatic, renal, and cerebral oxidative stress. The treatment of L. plantarum CCFM639 has potential as a therapeutic dietary strategy against acute aluminium toxicity.

Structural evolution in nanoporous anodic aluminium oxide

International Nuclear Information System (INIS)

Rocca, Emmanuel; Vantelon, Delphine; Reguer, Solenn; Mirambet, François

2012-01-01

Nanoporous and self-organized layers of aluminium alloys are used in many applications as membranes, templates for nanometric objects or corrosion protection for aluminium alloys. The use of this nanometric structure widely remains empirical, especially in the case of very small pores ( 4 into AlO 6 cluster and a partial release of sulphate ions are an important chemical transformation of the amorphous structure. This structural transformation defines the chemistry (pH and surface charge) inside the nanopores, the ageing behaviour and the possible incorporation or diffusion of chemical species in the nanostructure. Highlights: ► Investigations of local chemical environment of aluminium atoms in anodic aluminium oxide. ► The oxide structure is constituted by 2/3 of aluminium in tetrahedral coordination 1/3 in octahedral coordination. ► In contact with water, AlO 4 clusters are transformed into AlO 6 cluster and the aluminium sulphate bonds are hydrolysed. ► These transformations induce a pH decrease inside the nanostructure.

Aluminium, gallium, indium and thallium

International Nuclear Information System (INIS)

Brown, Paul L.; Ekberg, Christian

2016-01-01

Aluminium can exist in a number of oxyhydroxide mineral phases including corundum, diaspore, boehmite and gibbsite. The stability constants at zero ionic strength reported for Al(OH) 3 (aq) vary linearly with respect to the inverse of absolute temperature. A full suite of thermodynamic parameters is available for all aluminium phases and hydrolysis species. Gallium hydrolyses to a greater extent than aluminium, with the onset of hydrolysis reactions occurring just above a pHof 1. In fact, even though aluminium has the smallest ionic radius of this series of metals, it has the weakest hydrolysis species and oxide/hydroxide phases.This is due to the presence of stabilising d-orbitals in the heavier metals, gallium, indium and thallium(III). There are few available data for the stability constants of indium(III) hydrolysis species. Of those that are available, the range in the proposed stability constants covers many orders of magnitude.

Certification of an aluminium metal reference material for neutron dosimetry (EC nuclear reference material 523)

International Nuclear Information System (INIS)

Pauwels, J.; Ingelbrecht, C.

1990-01-01

Aluminium metal of > 99.999% nominal purity in the form of 0.1 mm and 1 mm thick foil and of 1 mm diameter wire has been certified for its sodium mass fraction. The certified value of the sodium mass fraction ( -1 ) is based on 21 results from three laboratories using two different methods, which are neutron activation analysis and atomic absorption spectrometry. The overall purity was estimated using spark source mass spectrometry and neutron activation analysis. The material is intended to be used as a reference material in neutron metrology

Boron carbide reinforced aluminium matrix composite: Physical, mechanical characterization and mathematical modelling

International Nuclear Information System (INIS)

Shirvanimoghaddam, K.; Khayyam, H.; Abdizadeh, H.; Karbalaei Akbari, M.; Pakseresht, A.H.; Ghasali, E.; Naebe, M.

2016-01-01

This paper investigates the manufacturing of aluminium–boron carbide composites using the stir casting method. Mechanical and physical properties tests to obtain hardness, ultimate tensile strength (UTS) and density are performed after solidification of specimens. The results show that hardness and tensile strength of aluminium based composite are higher than monolithic metal. Increasing the volume fraction of B_4C, enhances the tensile strength and hardness of the composite; however over-loading of B_4C caused particle agglomeration, rejection from molten metal and migration to slag. This phenomenon decreases the tensile strength and hardness of the aluminium based composite samples cast at 800 °C. For Al-15 vol% B_4C samples, the ultimate tensile strength and Vickers hardness of the samples that were cast at 1000 °C, are the highest among all composites. To predict the mechanical properties of aluminium matrix composites, two key prediction modelling methods including Neural Network learned by Levenberg–Marquardt Algorithm (NN-LMA) and Thin Plate Spline (TPS) models are constructed based on experimental data. Although the results revealed that both mathematical models of mechanical properties of Al–B_4C are reliable with a high level of accuracy, the TPS models predict the hardness and tensile strength values with less error compared to NN-LMA models.

Ocular toxicity of authentic lunar dust.

Science.gov (United States)

Meyers, Valerie E; Garcìa, Hector D; Monds, Kathryn; Cooper, Bonnie L; James, John T

2012-07-20

Dust exposure is a well-known occupational hazard for terrestrial workers and astronauts alike and will continue to be a concern as humankind pursues exploration and habitation of objects beyond Earth. Humankind's limited exploration experience with the Apollo Program indicates that exposure to dust will be unavoidable. Therefore, NASA must assess potential toxicity and recommend appropriate mitigation measures to ensure that explorers are adequately protected. Visual acuity is critical during exploration activities and operations aboard spacecraft. Therefore, the present research was performed to ascertain the ocular toxicity of authentic lunar dust. Small (mean particle diameter = 2.9 ± 1.0 μm), reactive lunar dust particles were produced by grinding bulk dust under ultrapure nitrogen conditions. Chemical reactivity and cytotoxicity testing were performed using the commercially available EpiOcularTM assay. Subsequent in vivo Draize testing utilized a larger size fraction of unground lunar dust that is more relevant to ocular exposures (particles lunar dust was minimally irritating. Minor irritation of the upper eyelids was noted at the 1-hour observation point, but these effects resolved within 24 hours. In addition, no corneal scratching was observed using fluorescein stain. Low-titanium mare lunar dust is minimally irritating to the eyes and is considered a nuisance dust for ocular exposure. No special precautions are recommended to protect against ocular exposures, but fully shielded goggles may be used if dust becomes a nuisance.

Challenges in LCA modelling of multiple loops for aluminium cans

DEFF Research Database (Denmark)

Niero, Monia; Olsen, Stig Irving

considered the case of closed-loop recycling for aluminium cans, where body and lid are different alloys, and discussed the abovementioned challenge. The Life Cycle Inventory (LCI) modelling of aluminium processes is traditionally based on a pure aluminium flow, therefore neglecting the presence of alloying...... elements. We included the effect of alloying elements on the LCA modelling of aluminium can recycling. First, we performed a mass balance of the main alloying elements (Mn, Fe, Si, Cu) in aluminium can recycling at increasing levels of recycling rate. The analysis distinguished between different aluminium...... packaging scrap sources (i.e. used beverage can and mixed aluminium packaging) to understand the limiting factors for multiple loop aluminium can recycling. Secondly, we performed a comparative LCA of aluminium can production and recycling in multiple loops considering the two aluminium packaging scrap...

Durability of bare and anodised aluminium in atmosphere of very different corrosivities I. Bare aluminium

International Nuclear Information System (INIS)

Gonzalez, J. A.; Escudero, E.; Lopez, V.; Simancas, J.; Morcillo, M.

2004-01-01

The behaviour of bare aluminium is studied in atmospheric exposure at 11 natural testing stations with salinity levels ranging between 2.1 and 684 mg Cl''- m''-2 d''-1. In atmospheres of low or moderate aggressivity aluminium behaves as a passive material, though the insignificant corrosion that is produced is sufficient to spoil its appearance. In contrast, at salinity levels of 50 mg Cl''- m''-2 ''-1 or above, aluminium is susceptible to pitting corrosion even in the first year of atmospheric exposure, or in the second year at salinities of ≤ 10 mg Cl''- m''-2 d''-1. For comparative purposes, results are included for aluminium protected with an anodic film of 28 μm thickness exposed at the same testing stations. A 28 μm anodic film, correctly sealed, prevents the risk of localised corrosion even in the most unfavourable situations. (Author) 23 refs

Fatigue test on aluminium bridges

NARCIS (Netherlands)

Maljaars, J.; Soetens, F.; Straalen, van IJ.J.

2005-01-01

Traffic bridges are subjected to variable loads and should therefore be checked on fatigue. Especially low weight materials, like aluminium, are sensitive to fatigue, because the variable load is a substantial part of the total load. This paper shows the structural design of an aluminium bridge

Production and characterization of aluminium oxide nanoshells on spray dried lactose.

Science.gov (United States)

Hellrup, Joel; Rooth, Mårten; Johansson, Anders; Mahlin, Denny

2017-08-30

Atomic layer deposition (ALD) enables deposition of dense nanometer thick metal oxide nanoshells on powder particles with precise thickness control. This leads to products with low weight fraction coating, also when depositing on nano- or micron sized powder particles. This study aimed at investigating the aluminium oxide nanoshell thickness required to prevent moisture sorption. The nanoshells were produced with ALD on spray-dried lactose, which is amorphous and extremely hygroscopic. The particles were studied with dynamic vapor sorption between 0 and 50% RH, light scattering, scanning electron microscopy, X-ray diffraction, differential scanning calorimetry, and polarized light microscopy. The ALD did not induce any recrystallization of the amorphous lactose. The dynamic vapor sorption indicated that the moisture sorption was almost completely inhibited by the nanoshell. Neat amorphous lactose rapidly recrystallized upon moisture exposure. However, only ca. 15% of the amorphous lactose particles recrystallized of a sample with 9% (by weight) aluminium oxide nanoshell at storage for six months upon 75% RH/40°C, which indicate that the moisture sorption was completely inhibited in the majority of the particles. In conclusion, the aluminium oxide nanoshells prevented moisture sorption and dramatically improved the long term physical stability of amorphous lactose. This shows the potential of the ALD-technique to protect drug microparticles. Copyright © 2017 Elsevier B.V. All rights reserved.

Fatal aluminium phosphide poisoning

Directory of Open Access Journals (Sweden)

Meena Mahesh Chand

2015-06-01

Full Text Available Aluminium phosphide (AlP is a cheap solid fumigant and a highly toxic pesticide which is commonly used for grain preservation. AlP has currently aroused interest with a rising number of cases in the past four decades due to increased use for agricultural and non-agricultural purposes. Its easy availability in the markets has increased also its misuse for committing suicide. Phosphine inhibits cellular oxygen utilization and can induce lipid peroxidation. Poisoning with AlP has often occurred in attempts to commit suicide, and that more often in adults than in teenagers. This is a case of suicidal consumption of aluminium phosphide by a 32-year-old young medical anesthetist. Toxicological analyses detected aluminium phosphide. We believe that free access of celphos tablets in grain markets should be prohibited by law.

Friction Welding of Aluminium and Aluminium Alloys with Steel

Directory of Open Access Journals (Sweden)

Andrzej Ambroziak

2014-01-01

Full Text Available The paper presents our actual knowledge and experience in joining dissimilar materials with the use of friction welding method. The joints of aluminium and aluminium alloys with the different types of steel were studied. The structural effects occurring during the welding process were described. The mechanical properties using, for example, (i microhardness measurements, (ii tensile tests, (iii bending tests, and (iv shearing tests were determined. In order to obtain high-quality joints the influence of different configurations of the process such as (i changing the geometry of bonding surface, (ii using the interlayer, or (iii heat treatment was analyzed. Finally, the issues related to the selection of optimal parameters of friction welding process were also investigated.

Vacuum brazing of aluminium metal matrix composite (55 vol.% SiC{sub p}/A356) using aluminium-based filler alloy

Energy Technology Data Exchange (ETDEWEB)

Niu, Jitai, E-mail: niujitai@163.com [Harbin Institute of Technology (China); Zhengzhou University (China); Luo, Xiangwei; Tian, Hao [Zhengzhou University (China); Brnic, Josip [University of Rijka (Croatia)

2012-11-20

Highlights: Black-Right-Pointing-Pointer The proper filler metal has been developed, especially for contents of Mg and Si. Black-Right-Pointing-Pointer The pressure device has been designed for specimen in vacuum brazing process. Black-Right-Pointing-Pointer The accurate measurement method for shear strength of lap joint has been found. Black-Right-Pointing-Pointer The brazing temperature of 560 Degree-Sign C has been optimised. Black-Right-Pointing-Pointer The micro-mechanism has been discussed for SiC{sub p}/Al composites' brazing joint. - Abstract: Aluminium matrix composites with high volume fractions of SiC particles, as the reinforcements, are potentially suitable materials for electronic packaging. These composites, due to their poor weldability, however, have very limited applications. The microstructure and shear strengths of the bonds made in 55 vol.% SiC{sub p}/A356 composite, using an aluminium based filler alloy containing Cu, Si, Mg and Ni, were investigated in this paper. The brazing temperature had a clear effect on the bond integrity, and the samples brazed at 560 Degree-Sign C demonstrated good bonding between the filler alloy and the SiC particles. The maximum shear strength achieved in this work was 102 MPa.

Aluminium cables in automotive applications : Prestudy of aluminium cable uses in Scania products&Failure analysis and evaluation

OpenAIRE

Man, Yu

2016-01-01

The increasing demand of light constructed vehicles as well as soaring price of copper metal owing to limited nature resources have been promoting the use of aluminium metal as an alternative conductor of automotive cables. This thesis work is to lay theoretical foundations for further research and development regarding the introduction of new automotive cables i.e. aluminium cables. Current application of automotive aluminium cables in automotive industry as well as failure analysis and eval...

Application of radioactivation analysis for determination of impurities in aluminium, raw materials and in samples from aluminium production process

International Nuclear Information System (INIS)

Vucina, L.J.

1977-01-01

Trace elements in aluminium, raw materials and in the samples from different stages of aluminium production were determined by nondestructive neutron radioactivation analysis. The samples were taken from the Bayer's process of alumina production (bauxite, red sludge and alumina), from the components of the reduction cell (anode, criolyte and AlF 3 ) and of the final product - aluminium (purity 99.5-99.7%). Under given set of conditions ten trace elements (V,La,Ga,Mn,Co,Cr,Sc,Sb,Zn and Fe) were determined in aluminium and followed through the production process. It was found that the main impurities in aluminium are iron (0.15%) and zinc (0.O6%). It has been concluded that the purity of produced aluminium depends mainly on the purity of used alumina. The second important source of contamination of aluminium is anode. The results obtained by radioactivation analysis for V, Mn, Cr and Fe fall within the ranges of concentrations of these elements determined by use of other methods (volumetry, spectrophotometry, atomic absorption). Higher values for zinc were obtained by radioactivation analysis, probably due to unsatisfactory irradiation and measuring conditions for this element. The possibilities of application of radioactivation analysis to these kinds of samples are also disscused

How the Assumed Size Distribution of Dust Minerals Affects the Predicted Ice Forming Nuclei

Science.gov (United States)

Perlwitz, Jan P.; Fridlind, Ann M.; Garcia-Pando, Carlos Perez; Miller, Ron L.; Knopf, Daniel A.

2015-01-01

The formation of ice in clouds depends on the availability of ice forming nuclei (IFN). Dust aerosol particles are considered the most important source of IFN at a global scale. Recent laboratory studies have demonstrated that the mineral feldspar provides the most efficient dust IFN for immersion freezing and together with kaolinite for deposition ice nucleation, and that the phyllosilicates illite and montmorillonite (a member of the smectite group) are of secondary importance.A few studies have applied global models that simulate mineral specific dust to predict the number and geographical distribution of IFN. These studies have been based on the simple assumption that the mineral composition of soil as provided in data sets from the literature translates directly into the mineral composition of the dust aerosols. However, these tables are based on measurements of wet-sieved soil where dust aggregates are destroyed to a large degree. In consequence, the size distribution of dust is shifted to smaller sizes, and phyllosilicates like illite, kaolinite, and smectite are only found in the size range 2 m. In contrast, in measurements of the mineral composition of dust aerosols, the largest mass fraction of these phyllosilicates is found in the size range 2 m as part of dust aggregates. Conversely, the mass fraction of feldspar is smaller in this size range, varying with the geographical location. This may have a significant effect on the predicted IFN number and its geographical distribution.An improved mineral specific dust aerosol module has been recently implemented in the NASA GISS Earth System ModelE2. The dust module takes into consideration the disaggregated state of wet-sieved soil, on which the tables of soil mineral fractions are based. To simulate the atmospheric cycle of the minerals, the mass size distribution of each mineral in aggregates that are emitted from undispersed parent soil is reconstructed. In the current study, we test the null

Study of dust re-suspension at low pressure in a dedicated wind-tunnel

Science.gov (United States)

Rondeau, Anthony; Sabroux, Jean-Christophe; Chassefière, Eric

2015-04-01

The atmosphere of several telluric planets or satellites are dusty. Such is the case of Earth, Venus, Mars and Titan, each bearing different aeolian processes linked principally to the kinematic viscosity of the near-surface atmosphere. Studies of the Martian atmosphere are particularly relevant for the understanding of the dust re-suspension phenomena at low pressure (7 mbar). It turns out that operation of fusion reactors of the tokamak design produces significant amount of dust through the erosion of plasma-facing components. Such dust is a key issue, both regarding the performance and the safety of a fusion reactor such as ITER, under construction in Cadarache, France. Indeed, to evaluate the explosion risk in the ITER fusion reactor, it is essential to quantify the re-suspended dust fraction as a function of the dust inventory that can be potentially mobilized during a loss of vacuum accident (LOVA), with air or water vapour ingress. A complete accident sequence will encompass dust re-suspension from near-vacuum up to atmospheric pressure. Here, we present experimental results of particles re-suspension fractions measured at 1000, 600 and 300 mbar in the IRSN BISE (BlowIng facility for airborne releaSE) wind tunnel. Both dust monolayer deposits and multilayer deposits were investigated. In order to obtain experimental re-suspension data of dust monolayer deposits, we used an optical microscope allowing to measure the re-suspended particles fraction by size intervals of 1 µm. The deposits were made up of tungsten particles on a tungsten surface (an ubiquitous plasma facing component) and alumina particles on a glass plate, as a surrogate. A comparison of the results with the so-called Rock'nRoll dust re-suspension model (Reeks and Hall, 2001) is presented and discussed. The multilayer deposits were made in a vacuum sedimentation chamber allowing to obtain uniform deposits in terms of thickness. The re-suspension experimental data of such deposits were obtained

Statistical method for the determination of the ignition energy of dust cloud - experimental validation

Energy Technology Data Exchange (ETDEWEB)

Bernard, S.; Lebecki, K.; Gillard, P.; Youinou, L.; Baudry, G. [University of Orleans, Bourges (France)

2010-05-15

Powdery materials such as metallic or polymer powders play a considerable role in many industrial processes. Their use requires the introduction of preventive safeguard to control the plants safety. The mitigation of an explosion hazard, according to the ATEX 137 Directive (1999/92/EU), requires the assessment of the dust ignition sensitivity. PRISME laboratory (University of Orleans) has developed an experimental set-up and methodology, using the Langlie test, for the quick determination of the explosion sensitivity of dusts. This method requires only 20 shots and ignition sensitivity is evaluated through the E{sub 50} (energy with an ignition probability of 0.5) A Hartmann tube, with a volume of 1.3l, was designed and built. Many results on the energy ignition thresholds of partially oxidised aluminium were obtained using this experimental device and compared to literature. E-50 evolution is the same as MIE but their respective values are different and MIE is lower than E{sub 50} however the link between E{sub 50} and MIE has not been elucidated In this paper, the Langlie method is explained in detail for the determination of the parameters (mean value E{sub 50} and standard deviation {sigma}) of the associated statistic law. The ignition probability versus applied energy is firstly measured for Lycopodium in order to validate the method A comparison between the normal and the lognormal law was achieved and the best fit was obtained with the lognormal law. In a second part, the Langlie test was performed on different dusts such as aluminium, cornstarch, lycopodium, coal, and PA12 in order to determine E-50 and {sigma} for each dust. The energies E{sub 05} and E{sub 10} corresponding respectively to an ignition probability of 0.05 and 0.1 are determined with the lognormal law and compared to MIE find in literature. E{sub 05} and E{sub 10} values of ignition energy were found to be very close and were in good agreement with MIE in the literature.

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

Science.gov (United States)

Kramer, Matthias F; Heath, Matthew D

2014-07-16

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

Spark counting technique with an aluminium oxide film

International Nuclear Information System (INIS)

Kawai, H.; Koga, T.; Morishima, H.; Niwa, T.; Nishiwaki, Y.

1980-01-01

Automatic spark counting of etch-pits on a polycarbonate film produced by nuclear fission fragments is now used for neutron monitoring in several countries. A method was developed using an aluminium oxide film instead of a polycarbonate as the neutron detector. Aluminium oxide films were prepared as follows: A cleaned aluminium plate as an anode and a nickel plate as a cathode were immersed in dilute sulfuric acid solution and electric current flowed between the electrodes at 12degC for 10-30 minutes. Electric current density was about 10 mA/cm 2 . The aluminium plate was then kept in boiling water for 10-30 minutes for sealing. The thickness of the aluminium oxide layer formed was about 1μm. The aluminium plate attached to a plate of suitable fissionable material, such as uranium or thorium, was irradiated with neutrons and set in a usual spark counter for fission track counting. One electrode was the aluminium plate and the other was an aluminized polyester sheet. Sparked pulses were counted with a usual scaler. The advantage of using spark counting with an aluminium oxide film for neutron monitoring is rapid measurement of neutron exposure, since chemical etching which is indispensable for spark counting with a polycarbonate detector film, is not needed. (H.K.)

Steam generated conversion coating on aluminium alloys

DEFF Research Database (Denmark)

Din, Rameez Ud; Jellesen, Morten Stendahl; Ambat, Rajan

Aluminium and its alloys are widely used in aerospace industry owing to their high strength to weight ratio. The surface of aluminium under normal conditions has a thin oxide film (2.5-10 nm) responsible for its inherent corrosion resistance. This oxide film can further be converted or transformed...... into functional conversion coatings in order to enhance corrosion resistance and adhesion to paint systems. Chromium based conversion coatings have been extensively used on aluminium alloys to improve adhesion of subsequent paint layers and corrosion resistance. However, the use of hexavalent chromium is strictly...... regulated due to its toxic nature and suspected carcinogenicity. So, it is highly imperative to develop other alternatives for chrome conversion coatings. Treatment of aluminium with natural water at elevated temperatures results in the formation of different forms of aluminium oxide (γ-AlO(OH) , Al(OH)3...

Magnetic studies of dusts in the urban environment

International Nuclear Information System (INIS)

Xie, S.

2000-12-01

Dusts are one of the major public health concerns in the urban environment. This study investigates the application of magnetic techniques in the studies of urban dust pollution. Measurements of magnetic properties, element concentrations, and the organic matter content were carried out on Liverpool (UK) street dust and/or Bootle (UK) deposited dust. Mixed dominant ferrimagnetic phases are found in Liverpool street dust although magnetite is probably a major one. The partial susceptibility technique is able to model the contributions of main magnetic components satisfactorily in Liverpool street dust. There are similar spatial distributions for some measurements, such as χLF and Pb, whilst there are different patterns for some measurements, such as χLF and the organic matter content. There are good linear correlations between the organic matter content and some magnetic mineral concentration-related parameters for < 1mm (bulk) samples. Among them, frequency dependent susceptibility (χFD) shows the highest correlation coefficient value. χFD percentage demonstrates a significant correlation with the organic matter content for size fraction and bulk samples. This suggests that re-entrainment of soil is probably a major source of the organic material present in street dust. The ratio χARM /SIRM shows a highly significant correlation with the organic matter content for <150μm fraction samples. The study demonstrates that the simple, rapid, and non-destructive magnetic measurements may be used as proxies for the organic matter content in street dust. Associations between magnetic properties and element concentrations are investigated by using correlation analysis and factor analysis, which may be a potential approach for source identification of magnetic material in the environment. The study suggests that ferrimagnetic minerals are the dominant magnetic component in Bootle dust samples. Both studied sites show similar magnetic properties, but they can be

Advances in development and application of aluminium batteries

DEFF Research Database (Denmark)

Qingfeng, Li; Zhuxian, Qiu

2001-01-01

Aluminium has long attracted attention as a potential battery anode because of its high theoretical voltage and specific energy. The protective oxide layer at aluminium surface is however detrimental to its performance to achieve its reversible potential, and also causing the delayed activation o...... aluminium batteres, especially aluminium-air batteries, and a wide range of their applications from emergency power supplies, reserve batteries field portable batteries, to batteries for electric vehicles and underwater propulsion....

Heavy metal levels and solid phase speciation in street dusts of Delhi, India

International Nuclear Information System (INIS)

Banerjee, Anju D.K.

2003-01-01

Although the street dusts of Delhi contain considerably high levels of Cr, Ni, Cu, Cd, Zn and Pb, solid phase speciation results indicate comparatively limited environmental mobility and bioavailability of Ni and Cr. - Street dust samples were collected from three different localities (industrial, heavy traffic and rural) situated in the greater Delhi area of India. The samples analyzed for Cd, Zn, Pb, Ni, Cu, and Cr indicated remarkably high levels of Cr, Ni, and Cu in the industrial area, whilst Pb and Cd did not show any discernible variations between the three localities. A multivariate statistical approach (Principal Component Analysis) was used to define the possible origin of metals in dusts. The street dusts were sequentially extracted so that the solid pools of Cd, Zn, Pb, Ni, Cu, Cr could be partitioned into five operationally defined fractions viz. exchangeable, bound to carbonates, bound to Fe-Mn oxides, bound to organic matter and residual. Metal recoveries in sequential extractions were ±10% of the independently measured total metal concentrations. Cd was the only metal present appreciably (27.16%) in the exchangeable fraction and Cu was the only metal predominantly associated (44.26%) with organic fraction. Zn (45.64%) and Pb (28.26%) were present mainly in the Fe-Mn oxide fraction and the residual fraction was the most dominant solid phase pool of Cr (88.12%) and Ni (70.94%). Assuming that the mobility and bioavailability are related to the solubility of geochemical forms of the metals and decrease in order of extraction, the apparent mobility and potential metal bioavailability for these highly contaminated street dust samples is: Cd>Zn congruent with Pb>Ni>Cu>Cr

Dust in protoplanetary disks: observations*

Directory of Open Access Journals (Sweden)

Waters L.B.F.M.

2015-01-01

Full Text Available Solid particles, usually referred to as dust, are a crucial component of interstellar matter and of planet forming disks surrounding young stars. Despite the relatively small mass fraction of ≈1% (in the solar neighborhood of our galaxy; this number may differ substantially in other galaxies that interstellar grains represent of the total mass budget of interstellar matter, dust grains play an important role in the physics and chemistry of interstellar matter. This is because of the opacity dust grains at short (optical, UV wavelengths, and the surface they provide for chemical reactions. In addition, dust grains play a pivotal role in the planet formation process: in the core accretion model of planet formation, the growth of dust grains from the microscopic size range to large, cm-sized or larger grains is the first step in planet formation. Not only the grain size distribution is affected by planet formation. Chemical and physical processes alter the structure and chemical composition of dust grains as they enter the protoplanetary disk and move closer to the forming star. Therefore, a lot can be learned about the way stars and planets are formed by observations of dust in protoplanetary disks. Ideally, one would like to measure the dust mass, the grain size distribution, grain structure (porosity, fluffiness, the chemical composition, and all of these as a function of position in the disk. Fortunately, several observational diagnostics are available to derive constrains on these quantities. In combination with rapidly increasing quality of the data (spatial and spectral resolution, a lot of progress has been made in our understanding of dust evolution in protoplanetary disks. An excellent review of dust evolution in protoplanetary disks can be found in Testi et al. (2014.

Infrared emission from isolated dust clouds in the presence of very small dust grains

Science.gov (United States)

Lis, Dariusz C.; Leung, Chun M.

1991-01-01

Models of the effects of small grain-generated temperature fluctuations on the IR spectrum and surface brightness of externally heated interstellar dust clouds are presently constructed on the basis of a continuum radiation transport computer code which encompasses the transient heating of small dust grains. The models assume a constant fractional abundance of large and small grains throughout the given cloud. A comparison of model results with IRAS observations indicates that the observed 12-25 micron band emissions are associated with about 10-A radius grains, while the 60-100 micron emission is primarily due to large grains which are heated under the equilibrium conditions.

Ion beam analysis of aluminium in thin layers

International Nuclear Information System (INIS)

Healy, M.J.F.; Pidduck, A.J.; Dollinger, G.; Gorgens, L.; Bergmaier, A.

2002-01-01

This work quantifies aluminium in thin surface and near surface layers. In one example, the layer overlies a thin gallium nitride layer on an aluminium oxide substrate and in a second example the aluminium exists just below the surface of an indium arsenide substrate. The technique of non-Rutherford elastic backscattering of protons was used for the samples where aluminum in the layer of interest needed to be resolved from aluminium in the sapphire substrate and the results were corroborated at the Technische Universitaet Muenchen using heavy ion elastic recoil detection analysis. In the second example, where it was unnecessary to isolate the signal of aluminium in the layer of interest (as the substrate contained no aluminium), then the 27 Al(d,p 01 ) 28 Al nuclear reaction was used. The elastic proton scattering cross section of aluminum was found to vary very rapidly over the energy range of interest

The aluminium content of infant formulas remains too high.

Science.gov (United States)

Chuchu, Nancy; Patel, Bhavini; Sebastian, Blaise; Exley, Christopher

2013-10-08

Recent research published in this journal highlighted the issue of the high content of aluminium in infant formulas. The expectation was that the findings would serve as a catalyst for manufacturers to address a significant problem of these, often necessary, components of infant nutrition. It is critically important that parents and other users have confidence in the safety of infant formulas and that they have reliable information to use in choosing a product with a lower content of aluminium. Herein, we have significantly extended the scope of the previous research and the aluminium content of 30 of the most widely available and often used infant formulas has been measured. Both ready-to-drink milks and milk powders were subjected to microwave digestion in the presence of 15.8 M HNO3 and 30% w/v H2O2 and the aluminium content of the digests was measured by TH GFAAS. Both ready-to-drink milks and milk powders were contaminated with aluminium. The concentration of aluminium across all milk products ranged from ca 100 to 430 μg/L. The concentration of aluminium in two soya-based milk products was 656 and 756 μg/L. The intake of aluminium from non-soya-based infant formulas varied from ca 100 to 300 μg per day. For soya-based milks it could be as high as 700 μg per day. All 30 infant formulas were contaminated with aluminium. There was no clear evidence that subsequent to the problem of aluminium being highlighted in a previous publication in this journal that contamination had been addressed and reduced. It is the opinion of the authors that regulatory and other non-voluntary methods are now required to reduce the aluminium content of infant formulas and thereby protect infants from chronic exposure to dietary aluminium.

Preparation of aluminium lakes by electrocoagulation

OpenAIRE

Prapai Pradabkham

2008-01-01

Aluminium lakes have been prepared by electrocoagulation employing aluminium as electrodes. The electrocoagulation is conducted in an aqueous alcoholic solution and is completed within one hour. The dye content in the lake ranges approximately between 4-32%.

In vitro release of arachidonic acid and in vivo responses to respirable fractions of cotton dust

International Nuclear Information System (INIS)

Thomson, T.A.; Edwards, J.H.; Al-Zubaidy, T.S.; Brown, R.C.; Poole, A.; Nicholls, P.J.

1986-01-01

It was considered that the fall in lung function seen after exposure to cotton dust may be attributable in part to the activity of arachidonic acid metabolites, such as leucotrienes as well as to the more established release of histamine by cotton dust. However, we found that cotton and barley dusts elicited poor release of arachidonic acid from an established macrophage like cell line compared with that observed with other organic dusts. In the experimental animal, pulmonary cellular responses to both cotton and barley dust were similar to those evoked by moldy hay and pigeon dropping dusts, although after multiple doses a more severe response was seen to cotton and barley. Since both moldy hay and pigeon droppings elicit a greater arachidonic acid release than cotton or barley, a role for arachidonic acid in inducing the cellular response is less likely than other factors. There are limitations to our conclusions using this system, i.e., the arachidonic acid may be released in a nonmetabolized form, although it is noted that the two dusts with the greatest arachidonic acid release produce their clinical responses in humans largely by hypersensitivity mechanisms

The Interaction between Particles and Low Angle Boundaries during Recovering of Aluminium-Alumina Alloys

DEFF Research Database (Denmark)

Jones, A.R.; Hansen, Niels

1981-01-01

Certain quantitative and qualitative aspects both of subgrain growth and of the interaction between particles and low angle grain boundaries during recovery have been investigated in two aluminium alloys containing low volume fractions of small alumina particles. Quantitative data have been...... pinning. The discrepancies between the experimental and theoretical results can be rationalised in terms of the limited nature of the physical effects modelled in the Zener analysis....

CV-Dust: Atmospheric aerosol in the Cape Verde region: carbon and soluble fractions of PM10

Science.gov (United States)

Pio, C.; Nunes, T.; Cardoso, J.; Caseiro, A.; Custódio, D.; Cerqueira, M.; Patoilo, D.; Almeida, S. M.; Freitas, M. C.

2012-04-01

Every year, billions of tons of eroded mineral soils from the Saharan Desert and the Sahel region, the largest dust source in the world, cross Mediterranean towards Europe, western Asia and the tropical North Atlantic Ocean as far as the Caribbean and South America. Many aspects of the direct and indirect effects of dust on climate are not well understood and the bulk and surface chemistry of the mineral dust particles determines interactions with gaseous and other particle species. The quantification of the magnitude of warming or cooling remains open because of the strong variability of the atmospheric dust burden and the lack of representative data for the spatial and temporal distribution of the dust composition. CV-Dust is a project that aims at provide a detailed data on the size distribution and the size-resolved chemical and mineralogical composition of dust emitted from North Africa using a natural laboratory like Cape Verde. This archipelago is located in an area of massive dust transport from land to ocean, and is thus ideal to set up sampling devices that are able to characterize and quantify dust transported from Africa. Moreover, Cape Verde's future economic prospects depend heavily on the encouragement of tourism, therefore it is essential to elucidate the role of Saharan dust may play in the degradation of Cape Verde air quality. The main objectives of CV-Dust project are: 1) to characterize the chemical and mineralogical composition of dust transported from Africa by setting up an orchestra of aerosol sampling devices in the strategic archipelago of Cape Verde; 2) to identify the sources of particles in Cape Verde by using receptor models; 3) to elucidate the role Saharan dust may play in the degradation of Cape Verde air quality; 4) to model processes governing dust production, transport, interaction with the radiation field and removal from the atmosphere. Here we present part of the data obtained throughout the last year, involving a set of more

Serum aluminium levels of workers in the bauxite mines.

Science.gov (United States)

de Kom, J F; Dissels, H M; van der Voet, G B; de Wolff, F A

1997-01-01

Aluminium is produced from the mineral bauxite. Occupational exposure is reported during the industrial processing of aluminium and is associated with pulmonary and neurotoxicity. However, data on exposure and toxicity of workers in the open bauxite mining industry do not exist. Therefore, a study was performed to explore aluminium exposure in employees involved in this bauxite mining process in a Surinam mine. A group of workers occupationally exposed to aluminium in an open bauxite mine were compared with a group of nonexposed wood processors. Serum aluminium was analyzed using atomic absorption spectrometry Data from the clinical chemistry of the blood and a questionnaire were used to explore determinants for aluminium exposure. No significant difference between serum aluminium in the exposed (4.4 +/- 2.0 micrograms/L, n = 27) and control group (5.1 +/- 1.5 micrograms/L, n = 27) was detected. For the serum concentration of the clinical chemical variables (calcium, citrate, and creatinine), a statistically significant difference was computed (p < or = 0.02) between the exposed and control group. All levels were slightly higher in the exposed group; no statistically significant correlations with serum aluminium were found. In this study, serum aluminium values were in the normal range, no significant difference between the groups could be detected despite long-term occupational exposure.

Argon-arc welding of heat resisting aluminium alloys

International Nuclear Information System (INIS)

Ryazantsev, V.I.; Fedoseev, V.A.

1997-01-01

Welding of aluminium heat resisting alloys of the Al-Cu-Mg system is studied. The hot-shortness of heat-resistant alloys M40, 1150 and 1151 are at the level of aluminium alloys 1201 and by 2-3 times lower as compared to the aluminium alloy AMg6. The M40, 1150 and 1151 alloys have unquestionable advantages against other know aluminium alloys only at temperatures of welded structures operation, beginning with 150-2000 deg C and especially at 250 deg C

Net shape powder processing of aluminium

International Nuclear Information System (INIS)

Schaffer, G.B.

2000-01-01

The increasing interest in light weight materials coupled to the need for cost-effective processing have combined to create a significant opportunity for aluminium powder metallurgy. Net shape processing of aluminium using the classical press-and-sinter powder metallurgy technique is a unique and important metal-forming method which is cost effective in producing complex parts at, or very close to, final dimensions. This paper provides an overview of the net shape powder processing of aluminium. Current research is critically reviewed and the future potential is briefly considered

Extended dust in dwarf galaxies - solving an energy-budget paradox?

Science.gov (United States)

Keel, William C.; Holwerda, Benne; Lintott, Chris; Schawinski, Kevin

2012-02-01

The role of dust in shaping the emerging spectral energy distributions of galaxies remains poorly understood; recent Herschel results suggest large amounts of cold dust coupled with only modest optical extinction for much of the galaxy population. Previous work has used the discovery of a silhouetted-galaxy pair of a backlit dwarf galaxy with dust features extending beyond the de Vaucouleurs radius to investigate this question. We propose to examine a larger set of galaxies of this type drawn from the Galaxy Zoo catalog of silhouetted-galaxy pairs, to see whether a significant fraction of dwarfs have such extensive dust distributions. The catalog contains ~ 150 candidate backlit dwarfs; if such dust distributions are common enough to account for the Herschel results, we would see many additional cases of silhouetted dust beyond their stellar disks.

Preparation of aluminium lakes by electrocoagulation

Directory of Open Access Journals (Sweden)

Prapai Pradabkham

2008-07-01

Full Text Available Aluminium lakes have been prepared by electrocoagulation employing aluminium as electrodes. The electrocoagulation is conducted in an aqueous alcoholic solution and is completed within one hour. The dye content in the lake ranges approximately between 4-32%.

Investigation of aluminium state in some popular food, which are cooked in aluminium vessels, using spectroscopic analysis methods

International Nuclear Information System (INIS)

Al-Shahneh, M.; Saheune, Kh.

2009-01-01

Aluminium and lead elements were determined in drinking water and salt solution from chick-pea and faba-bean cooked in aluminium vessels and others from teflon for comparison using atomic absorption spectroscopy by graphite furnace. The relationship between heating time and aluminium quantities transferred to these food solutions was investigated. The lead element was determined taking into consideration the fact that this element may enter in these vessels somehow during the manufacturing process. Results show that the highest value of aluminium quantities was recorded in salt solution ( 17.022 μg/ml) without heating , followed by chick-pea solution (9.95 μg/ml), then faba-bean solution (2.81 μg/ml) when the heated period was 120 minutes. (author)

Effect of tempering on corrosion resistance of cast aluminium bronzes

International Nuclear Information System (INIS)

Aaltonen, P.; Klemetti, K.; Haenninen, H.

1985-01-01

The subject of this study is corrosion resistance of aluminium bronzes, which are copper base alloys containing aluminium up to 12% with additions of nickel, iron and manganese. The main conclutions that can be drawn are: (1) The dealloying corrosion resistance of nickel-aluminium bronze is much better than that of aluminium bronze with iron and manganese additions, but it is not immune; (2) The dealloying corrosion resistance of aluminium bronzes can be improved by appropiate heat treatments. The best properties were obtained by temperering between 600 and 800 deg C, depending on the initial microstructure; (3) In crevice conditions, where local acidification can occur, dealloying of aluminium bronzes is a consequence of the preferential attack of aluminium-rich phases. By appropriate tempering, a uniform distribution of aluminium-rich phases is obtained and the continous path for selective corrosion is not formed

What is the risk of aluminium as a neurotoxin?

Science.gov (United States)

Exley, Christopher

2014-06-01

Aluminium is neurotoxic. Its free ion, Al(3+) (aq), is highly biologically reactive and uniquely equipped to do damage to essential cellular (neuronal) biochemistry. This unequivocal fact must be the starting point in examining the risk posed by aluminium as a neurotoxin in humans. Aluminium is present in the human brain and it accumulates with age. The most recent research demonstrates that a significant proportion of individuals older than 70 years of age have a potentially pathological accumulation of aluminium somewhere in their brain. What are the symptoms of chronic aluminium intoxication in humans? What if neurodegenerative diseases such as Alzheimer's disease are the manifestation of the risk of aluminium as a neurotoxin? How might such an (outrageous) hypothesis be tested?

Detection of aluminium in different culinary media using black ...

African Journals Online (AJOL)

Jacques Blessing

The interactions between food and aluminium local kitchen utensils can be a potential source of aluminium released which can ... need to be adopted to preserve consumers' health. ..... Corrosion behaviour of different ... Aluminium beverage.

There is (still too much aluminium in infant formulas

Directory of Open Access Journals (Sweden)

Burrell Shelle-Ann M

2010-08-01

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

Molybdenum solubility in aluminium nitrate solutions

Energy Technology Data Exchange (ETDEWEB)

Heres, X.; Sans, D.; Bertrand, M.; Eysseric, C. [CEA, Centre de Marcoule, Nuclear Energy Division, DRCP, BP 17171, 30207 Bagnols-sur-Ceze Cedex (France); Brackx, E.; Domenger, R.; Excoffier, E. [CEA, Centre de Marcoule, Nuclear Energy Division, DTEC, BP 17171, 30207 Bagnols-sur-Ceze Cedex (France); Valery, J.F. [AREVA-NC, DOR/RDP, Paris - La Defense (France)

2016-07-01

For over 60 years, research reactors (RR or RTR for research testing reactors) have been used as neutron sources for research, radioisotope production ({sup 99}Mo/{sup 99m}Tc), nuclear medicine, materials characterization, etc... Currently, over 240 of these reactors are in operation in 56 countries. They are simpler than power reactors and operate at lower temperature (cooled to below 100 C. degrees). The fuel assemblies are typically plates or cylinders of uranium alloy and aluminium (U-Al) coated with pure aluminium. These fuels can be processed in AREVA La Hague plant after batch dissolution in concentrated nitric acid and mixing with UOX fuel streams. The aim of this study is to accurately measure the solubility of molybdenum in nitric acid solution containing high concentrations of aluminium. The higher the molybdenum solubility is, the more flexible reprocessing operations are, especially when the spent fuels contain high amounts of molybdenum. To be most representative of the dissolution process, uranium-molybdenum alloy and molybdenum metal powder were dissolved in solutions of aluminium nitrate at the nominal dissolution temperature. The experiments showed complete dissolution of metallic elements after 30 minutes long stirring, even if molybdenum metal was added in excess. After an induction period, a slow precipitation of molybdic acid occurs for about 15 hours. The data obtained show the molybdenum solubility decreases with increasing aluminium concentration. The solubility law follows an exponential relation around 40 g/L of aluminium with a high determination coefficient. Molybdenum solubility is not impacted by the presence of gadolinium, or by an increasing concentration of uranium. (authors)

Measurement of the electronic absorption coefficient for 57Co 14.4 keV gamma photons in aluminium using the Moessbauer effect as a monochromator

International Nuclear Information System (INIS)

Rajan, N.; Nigam, A.K.

1984-01-01

The total electronic absorption coefficient for 14.4 keV gamma photons in aluminium, has been measured experimentally, for the first time, using the Moessbauer effect as a monochromator. This data is important for the determination of background in Moessbauer recoilless fraction measurements especially if the energy of X-rays of the source host lattice lie near the 14.4 keV photon energy (e.g. in Rh and Pd) in which case electronic absorption coefficients should be known precisely. The coefficient obtained by interpolation from available values at other energies differ from our experimental value by as much as 20%. It is shown that this can lead to errors, in recoilless fraction values, which are far from negligible. The above absorption coefficient for aluminium was measured to be 11+-1 cm 2 /g. (orig.)

Niobium-base grain refiner for aluminium

International Nuclear Information System (INIS)

Silva Pontes, P. da; Robert, M.H.; Cupini, N.L.

1980-01-01

A new chemical grain refiner for aluminium has been developed, using inoculation of a niobium-base compound. When a bath of molten aluminium is inoculated whith this refiner, an intermetallic aluminium-niobium compound is formed which acts as a powerful nucleant, producing extremely fine structure comparable to those obtained by means of the traditional grain refiner based on titanium and boron. It was found that the refinement of the structure depends upon the weight percentage of the new refiner inoculated as well as the time of holding the bath after inoculation and before pouring, but mainly on the inoculating temperature. (Author) [pt

IEC 61267: Feasibility of type 1100 aluminium and a copper/aluminium combination for RQA beam qualities.

Science.gov (United States)

Leong, David L; Rainford, Louise; Zhao, Wei; Brennan, Patrick C

2016-01-01

In the course of performance acceptance testing, benchmarking or quality control of X-ray imaging systems, it is sometimes necessary to harden the X-ray beam spectrum. IEC 61267 specifies materials and methods to accomplish beam hardening and, unfortunately, requires the use of 99.9% pure aluminium (Alloy 1190) for the RQA beam quality, which is expensive and difficult to obtain. Less expensive and more readily available filters, such as Alloy 1100 (99.0% pure) aluminium and copper/aluminium combinations, have been used clinically to produce RQA series without rigorous scientific investigation to support their use. In this paper, simulation and experimental methods are developed to determine the differences in beam quality using Alloy 1190 and Alloy 1100. Additional simulation investigated copper/aluminium combinations to produce RQA5 and outputs from this simulation are verified with laboratory tests using different filter samples. The results of the study demonstrate that although Alloy 1100 produces a harder beam spectrum compared to Alloy 1190, it is a reasonable substitute. A combination filter of 0.5 mm copper and 2 mm aluminium produced a spectrum closer to that of Alloy 1190 than Alloy 1100 with the added benefits of lower exposures and lower batch variability. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Remediation of phosphate-contaminated water by electrocoagulation with aluminium, aluminium alloy and mild steel anodes.

Science.gov (United States)

Vasudevan, Subramanyan; Lakshmi, Jothinathan; Jayaraj, Jeganathan; Sozhan, Ganapathy

2009-05-30

The present study provides an electrocoagulation process for the remediation of phosphate-contaminated water using aluminium, aluminium alloy and mild steel as the anodes and stainless steel as the cathode. The various parameters like effect of anode materials, effect of pH, concentration of phosphate, current density, temperature and co-existing ions, and so forth, and the adsorption capacity was evaluated using both Freundlich and Langmuir isotherm models. The adsorption of phosphate preferably fitting the Langmuir adsorption isotherm suggests monolayer coverage of adsorbed molecules. The results showed that the maximum removal efficiency of 99% was achieved with aluminium alloy anode at a current density of 0.2 A dm(-2), at a pH of 7.0. The adsorption process follows second-order kinetics.

Magnetic, geochemical characterization and health risk assessment of road dust in Xuanwei and Fuyuan, China.

Science.gov (United States)

Tan, Zhengying; Lu, Senlin; Zhao, Hui; Kai, Xiao; Jiaxian, Peng; Win, Myat Sandar; Yu, Shang; Yonemochi, Shinich; Wang, Qingyue

2018-01-19

As an accumulation of solid organic and inorganic pollutant particles on outdoor ground surfaces, road dust is an important carrier of heavy metal contaminants and can be a valuable medium for characterizing urban environmental quality. Because the dusts can be an important source of atmospheric particles and take impact on human health, the aim of this study described in detail the mineralogical characteristics, morphology, and heavy metal content of road dust from Xuanwei and Fuyuan, locations with high lung cancer incidence. Our results show that the average concentrations of heavy metals in road dust were higher than their background values. Higher concentrations of heavy metals were found in the magnetic fractions (MFs) than in the non-magnetic fractions (NMFs). Magnetic measurements revealed high magnetic susceptibility values in the road dust samples, and the dominant magnetic carrier was magnetite. The magnetic grains were predominantly pseudo-single domain, multi-domain, and coarse-grained stable single domains (coarse SSD) in size. SEM/XRD analysis identified two groups of magnetic particles: spherules and angular/aggregate particles. Hazard index (HI) values for adults exposure to road dust samples, including MF, Bulk, and NMF, in both areas were lower or close to safe levels, while HI values for childhood exposure to magnetic fractions in both areas were very close or higher than safe levels. Cancer risks from road dust exposure in both areas were in the acceptable value range.

Effect of Lubrication on Sliding Wear of Red Mud Particulate Reinforced Aluminium Alloy 6061

OpenAIRE

N. Panwar; R.P. Poonia; G. Singh; R. Dabral; A. Chauhan

2017-01-01

In present study, Red mud, an industrial waste, has been utilized as a reinforcement material to fabricate Aluminium 6061 matrix based metal matrix composite. Taguchi L18 orthogonal array has been employed for fabrication of composite castings and for conducting the tribological experimentation. ANOVA analysis has been applied to examine the effect of individual parameters such as sliding condition: dry and wet, reinforcement weight fraction, load, speed, and sliding distance on specific wear...

Optical and microphysical properties of natural mineral dust and anthropogenic soil dust near dust source regions over northwestern China

Science.gov (United States)

Wang, Xin; Wen, Hui; Shi, Jinsen; Bi, Jianrong; Huang, Zhongwei; Zhang, Beidou; Zhou, Tian; Fu, Kaiqi; Chen, Quanliang; Xin, Jinyuan

2018-02-01

Mineral dust aerosols (MDs) not only influence the climate by scattering and absorbing solar radiation but also modify cloud properties and change the ecosystem. From 3 April to 16 May 2014, a ground-based mobile laboratory was deployed to measure the optical and microphysical properties of MDs near dust source regions in Wuwei, Zhangye, and Dunhuang (in chronological order) along the Hexi Corridor over northwestern China. Throughout this dust campaign, the hourly averaged (±standard deviation) aerosol scattering coefficients (σsp, 550 nm) of the particulates with aerodynamic diameters less than 2.5 µm (PM2.5) at these three sites were sequentially 101.5 ± 36.8, 182.2 ± 433.1, and 54.0 ± 32.0 Mm-1. Correspondingly, the absorption coefficients (σap, 637 nm) were 9.7 ± 6.1, 6.0 ± 4.6, and 2.3 ± 0.9 Mm-1; single-scattering albedos (ω, 637 nm) were 0.902 ± 0.025, 0.931 ± 0.037, and 0.949 ± 0.020; and scattering Ångström exponents (Åsp, 450-700 nm) of PM2.5 were 1.28 ± 0.27, 0.77 ± 0.51, and 0.52 ± 0.31. During a severe dust storm in Zhangye (i.e., from 23 to 25 April), the highest values of σsp2.5 ( ˜ 5074 Mm-1), backscattering coefficient (σbsp2.5, ˜ 522 Mm-1), and ω637 ( ˜ 0.993) and the lowest values of backscattering fraction (b2.5, ˜ 0.101) at 550 nm and Åsp2.5 ( ˜ -0.046) at 450-700 nm, with peak values of aerosol number size distribution (appearing at the particle diameter range of 1-3 µm), exhibited that the atmospheric aerosols were dominated by coarse-mode dust aerosols. It is hypothesized that the relatively higher values of mass scattering efficiency during floating dust episodes in Wuwei and Zhangye are attributed to the anthropogenic soil dust produced by agricultural cultivations.

Multiply-negatively charged aluminium clusters and fullerenes

Energy Technology Data Exchange (ETDEWEB)

Walsh, Noelle

2008-07-15

Multiply negatively charged aluminium clusters and fullerenes were generated in a Penning trap using the 'electron-bath' technique. Aluminium monoanions were generated using a laser vaporisation source. After this, two-, three- and four-times negatively charged aluminium clusters were generated for the first time. This research marks the first observation of tetra-anionic metal clusters in the gas phase. Additionally, doubly-negatively charged fullerenes were generated. The smallest fullerene dianion observed contained 70 atoms. (orig.)

In-vessel dust and tritium control strategy in ITER

Energy Technology Data Exchange (ETDEWEB)

Shimada, M., E-mail: michiya.shimada@iter.org [ITER Organization, Route de Vinon-sur-Verdon, 13115 St. Paul-lez-Durance (France); Pitts, R.A.; Ciattaglia, S.; Carpentier, S.; Choi, C.H.; Dell Orco, G.; Hirai, T.; Kukushkin, A.; Lisgo, S.; Palmer, J.; Shu, W.; Veshchev, E. [ITER Organization, Route de Vinon-sur-Verdon, 13115 St. Paul-lez-Durance (France)

2013-07-15

A baseline strategy for dust and tritium-inventory control and recovery in ITER has been established and preparations are underway for its implementation. Limits on dust and tritium-inventory are an integral part of the ITER safety case and are fixed at 1 kg for tritium, 1000 kg for mobilisable dust and 11 kg (beryllium)/76 kg (tungsten) for dust on hot surfaces. Maximum average T-retention rates of ∼1 g/shot are estimated for baseline inductive operation at Q{sub DT} = 10, suggesting that the in-vessel T-retention could reach the administrative limit of 640 g in as little as ∼2 months of operation. Baking is expected to remove a significant fraction of the T co-deposited on the divertor targets. Despite large uncertainties, dust quantities are expected to remain well below safety limits over the divertor cassette lifetime. In situ aspiration during divertor cassette exchange is foreseen as the main dust removal technique.

Irradiation of aluminium alloy materials with electron beam

International Nuclear Information System (INIS)

Konno, Osamu; Masumoto, Kazuyoshi

1982-01-01

It is a theme with a room for discussion to employ the stainless steel composed of longer half-life materials for the vacuum system of accelerators, from the viewpoint of radiation exposure. Therefore, it is desirable to use aluminium of shorter half-life in place of stainless steel. As a result of investigation on the above theme in the 1.2 GeV electron linac project in Tohoku University, it has been concluded that aluminium alloy vacuum chambers can reduce exposure dose by about one or two figures as compared with stainless steel ones. Of course, aluminium alloy contains trace amounts of Mg, Si, Ti, Cr, Mn, Fe, Zn, Cu and others. Therefore, four kinds of aluminium alloy considered to be usable have been examined for induced radioactivity by electron beam irradiation. Stainless steel SUS 304 has been also irradiated for comparison. Radiation energy has been 30 MeV and 200 MeV. When stainless steel and aluminium alloy were compared, aluminium alloy was very effective for reducing surface dose in low energy irradiation. In 200 MeV irradiation, the dose ratio of aluminium alloy to stainless steel became 1/30 to 1/100 after one week, though the dose difference between these two materials became smaller in 100 days or more after irradiation. If practical inspection and repair are implemented during the period from a few days to one week after shutdown, the aluminium alloy is preferable for exposure dose reduction even in high energy irradiation. (Wakatsuki, Y.)

Introduction. Aluminium production on electrolytic cells with calcined anodes

International Nuclear Information System (INIS)

Galushkin, N.V.

1995-01-01

This chapter presents the monograph content, which includes the description of physicochemical processes in aluminium electrolytic cells, and mechanism of electrolytic aluminium obtaining. The short description of aluminium electrolytic cells construction is presented in this book as well.

Aluminium allergy and granulomas induced by vaccinations for children

DEFF Research Database (Denmark)

Andersen, Rosa Marie O; Zachariae, Claus; Johansen, Jeanne Duus

2014-01-01

Vaccination with aluminium-adsorbed vaccines can induce aluminium allergy with persistent itching subcutaneous nodules at the injection site - vaccination granulomas. In this article we give an overview of childhood aluminium-adsorbed vaccines available in Denmark. Through literature studies we...

Synthesis and properties of bimetallic aluminium alkoxides

International Nuclear Information System (INIS)

Vyshinskaya, K.I.; Vasil'ev, G.A.; Vishnyakova, T.A.

1997-01-01

A single stage method of aluminium bimetallic alkoxide synthesis, which consists in activated aluminium reaction with metal salts in the relevant alcohols, has been developed. Properties of the compounds prepared are described

Beryllium electrodeposition on aluminium cathode from chloride melts

International Nuclear Information System (INIS)

Nichkov, I.F.; Novikov, E.A.; Serebryakov, G.A.; Kanashin, Yu.P.; Sardyko, G.N.

1980-01-01

Cathodic processes during beryllium deposition on liquid and solid aluminium cathodes are investigated. Mixture of sodium, potassium and beryllium chloride melts served as an lectrolyte. Beryllium ion discharge at the expense of alloy formation takes place at more positive potentials than on an indifferent cathode at low current densities ( in the case of liquid aluminium cathode). Metallographic analysis and measurements of microhardness have shown, that the cathodic product includes two phases: beryllium solid solution in aluminium and metallic beryllium. It is concluded, that aluminium-beryllium alloys with high cathodic yield by current can be obtained by the electrolytic method

Investigation process of alcoholysis of hydride aluminium-adobe

International Nuclear Information System (INIS)

Numanov, M.I.; Normatov, I.Sh.; Mirsaidov, U.M.

2001-01-01

Considering of that process of acid treatment of aluminium-adobe hydride realizes in the ethyl alcohol media it was necessary study the process of alcoholysis of AlH 3 and aluminium additives. In the end of article authors became to conclusion that deficiency of spontaneous alcoholysis of AlH 3 in adobe caused by protective action of fiber; solvate ability of LiCl and alkoxy aluminium hydride of lithium-LiCl·CO 2 H 5 OH, Li Al(OC 2 H 5 ) 4 ·nC 2 H 5 OH decreasing the expectancy of responding of alcohol with aluminium hydride

Dynamic behavior of polydisperse dust system in cryogenic gas discharge complex plasmas

NARCIS (Netherlands)

Antipov, S.N.; Schepers, L.P.T.; Vasiliev, M.M.; Petrov, O.F.

2016-01-01

Complex (dusty) plasmas of micron-sized CeO2 polydisperse particles in dc glow discharges at 77 and ∼ 10 K were experimentally investigated. It was obtained that dust structure in cryogenic gas discharge plasma can be a mixture of two fractions (components) with completely different dust ordering

SVOC partitioning between the gas phase and settled dust indoors

Science.gov (United States)

Weschler, Charles J.; Nazaroff, William W.

2010-09-01

Semivolatile organic compounds (SVOCs) are a major class of indoor pollutants. Understanding SVOC partitioning between the gas phase and settled dust is important for characterizing the fate of these species indoors and the pathways by which humans are exposed to them. Such knowledge also helps in crafting measurement programs for epidemiological studies designed to probe potential associations between exposure to these compounds and adverse health effects. In this paper, we analyze published data from nineteen studies that cumulatively report measurements of dustborne and airborne SVOCs in more than a thousand buildings, mostly residences, in seven countries. In aggregate, measured median data are reported in these studies for 66 different SVOCs whose octanol-air partition coefficients ( Koa) span more than five orders of magnitude. We use these data to test a simple equilibrium model for estimating the partitioning of an SVOC between the gas phase and settled dust indoors. The results demonstrate, in central tendency, that a compound's octanol-air partition coefficient is a strong predictor of its abundance in settled dust relative to its gas phase concentration. Using median measured results for each SVOC in each study, dustborne mass fractions predicted using Koa and gas-phase concentrations correlate reasonably well with measured dustborne mass fractions ( R2 = 0.76). Combined with theoretical understanding of SVOC partitioning kinetics, the empirical evidence also suggests that for SVOCs with high Koa values, the mass fraction in settled dust may not have sufficient time to equilibrate with the gas phase concentration.

KS R41B. A high performance steel-aluminium composite material; KS R41B. Ein Stahl-Aluminium-Verbundwerkstoff fuer hohe Belastungen

Energy Technology Data Exchange (ETDEWEB)

Deicke, K. [KS Gleitlager GmbH (Germany). Bereich Metall; Matucha, H.; Schubert, W. [KS Gleitlager GmbH, St. Leon-Rot (Germany); Steffens, T. [KS Gleitlager GmbH, Neckarsulm (Germany)

2002-08-01

Aluminium-tin alloys have been well-known for a long time and have proved to be suitable bearing materials for crankshaft bearings for many years. The known alloy AlZn4,5SiCuPb is one of the aluminium materials capable of sustaining the highest mechanical loads. In order to achieve optimum sliding properties, it would be necessary to increase the share of the soft lead phase in the alloy. This article by KS Gleitlager GmbH shows a reasonably priced manufacturing technology for high-performance aluminium-zinc-silicon-copper alloys. (orig.) [German] Die Aluminium-Zinn-Lagerlegierungen sind seit langem bekannt und haben sich seit Jahren als Lagerwerkstoff fuer Kurbelwellenlager bewaehrt. Die Legierung AlZn4,5SiCuPb gehoert zu den mechanisch am hoechsten belastbaren Aluminium-Werkstoffen. Um optimale Gleiteigenschaften zu erzielen, muesste in der Legierung der Anteil des weichen Bleis noch weiter erhoeht werden. Dieser Beitrag der KS Gleitlager GmbH zeigt eine kostenguenstige Herstelltechnologie fuer hochbelastbare Aluminium-Zink-Silizium-Kupfer-Legierungen. (orig.)

Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders

NARCIS (Netherlands)

De Kanter, J.L.C.G.

2006-01-01

Summary accompanying the thesis: Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders by Jens de Kanter This thesis presents the investigation of the crush behaviour of both monolithic aluminium cylinders and externally fibre reinforced aluminium cylinders. The research is based

Corrosion of aluminium in copper-aluminium couples under a marine environment: Influence of polyaniline deposited onto copper

International Nuclear Information System (INIS)

Vera, Rosa; Verdugo, Patricia; Orellana, Marco; Munoz, Eduardo

2010-01-01

Research highlights: → The presence of Polyaniline in the Al-Cu system produces a decrease in the oxygen reduction reaction. → In the marine enviroment, aluminium in Al-Cu couples, suffers pitting and exfoliation. → The aluminium deterioration increases with chloride and enviromental sulphur dioxide presence, mainly when it is united to bare copper. - Abstract: In this study, we examined how aluminium corrosion in Al-Cu/PANI galvanic couples in a marine environment is influenced by deposition of polyaniline (PANI) on copper. Polarization curves and immersion assays in 0.1 M NaCl were performed. The morphologies of etched Al and corrosion products were observed by SEM, and the Al ions in solution were quantified by atomic absorption spectroscopy. A reduction in aluminium damage due to galvanic corrosion was observed as a result of decreased effective area for the oxygen reduction reaction on Cu/PANI electrode. Furthermore, an electrochemical reduction of PANI from leucoemeraldine to emeraldine base is proposed.

Aluminium hydroxide-the carrier for catalysts coating

International Nuclear Information System (INIS)

Normatov, I.Sh.; Mirsaidov, U.M.

2003-01-01

At present time several methods of receiving aluminium hydroxide are exist. But all they differ by much staging of process connected with preliminary receiving of intermediate compounds, with application of expensive metallic aluminium

Effects of aluminium surface morphology and chemical modification on wettability

DEFF Research Database (Denmark)

Rahimi, Maral; Fojan, Peter; Gurevich, Leonid

2014-01-01

-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...

Accumulation and distribution characteristics of platinum group elements in roadside dusts in Beijing, China.

Science.gov (United States)

Gao, Bo; Yu, Yanke; Zhou, Huaidong; Lu, Jin

2012-06-01

The concentrations, distribution, and accumulation of platinum group elements (PGEs) were investigated in roadside dusts collected in four different foundational areas in Beijing during February to May 2010. The results showed that PGE levels in all samples were above the average upper crust values, with mean concentrations of 57.5 ng · g(-1) Pd, 28.2 ng · g(-1) Pt, and 9.8 ng · g(-1) Rh, respectively. Palladium concentration has increased rapidly in recent years. The rank of PGE levels in four different functional regions for roadside dusts was: heavy density traffic area > residential area > educational area > tourism area. Palladium, Pt, and Rh concentrations in dusts showed strong positive correlations, indicating a common traffic-related source of these metals. Meanwhile, PGEs in these samples were not correlated with other traffic-related metals except for Cr. The average PGE ratios of road dusts from Beijing were consistent with those in Germany and Western Australia, but lower than those in the United States and Mexico, indicating that various catalyst productions were used in different countries. In addition, grain-size partitioning of PGEs in dusts indicated that concentrations of PGEs differed from one particle size to another. The coarse fraction had higher PGE concentrations than the fine fraction in roadside dusts. These results showed that autocatalyst PGE contamination estimates in the environment would be significantly underestimated if only a fine-grain size fraction (<0.063 mm) is analyzed. Copyright © 2012 SETAC.

Aluminium removal from water after defluoridation with the electrocoagulation process.

Science.gov (United States)

Sinha, Richa; Mathur, Sanjay; Brighu, Urmila

2015-01-01

Fluoride is the most electronegative element and has a strong affinity for aluminium. Owing to this fact, most of the techniques used for fluoride removal utilized aluminium compounds, which results in high concentrations of aluminium in treated water. In the present paper, a new approach is presented to meet the WHO guideline for residual aluminium concentration as 0.2 mg/L. In the present work, the electrocoagulation (EC) process was used for fluoride removal. It was found that aluminium content in water increases with an increase in the energy input. Therefore, experiments were optimized for a minimum energy input to achieve the target value (0.7 mg/L) of fluoride in resultant water. These optimized sets were used for further investigations of aluminium control. The experimental investigations revealed that use of bentonite clay as coagulant in clariflocculation brings down the aluminium concentration of water below the WHO guideline. Bentonite dose of 2 g/L was found to be the best for efficient removal of aluminium.

Irradiation effects in magnesium and aluminium alloys

International Nuclear Information System (INIS)

Sturcken, E.F.

1979-01-01

Effects of neutron irradiation on microstructure, mechanical properties and swelling of several magnesium and aluminium alloys were studied. The neutron fluences of 2-3 X 10 22 n/cm 2 , >0.2 MeV produced displacement doses of 20 to 45 displacements per atom (dpa). Ductility of the magnesium alloys was severely reduced by irradiation induced recrystallization and precipitation of various forms. Precipitation of transmuted silicon occurred in the aluminium alloys. However, the effect on ductility was much less than for the magnesium alloys. The magnesium and aluminium alloys had excellent resistance to swelling: The best magnesium alloy was Mg/3.0 wt% Al/0.19 wt% Ca; its density decreased by only 0.13%. The best aluminium alloy was 6063, with a density decrease of 0.22%. (Auth.)

Steam Initiated Surface Modification of Aluminium Alloys

DEFF Research Database (Denmark)

Din, Rameez Ud

The extensive demand of aluminium alloys in various industries such as in transportationis mainly due to the high strength to weight ratio, which could be translated into fuel economy and efficiency. Corrosion protection of aluminium alloys is an important aspect for all applications which includes...... the use of aluminium alloys in the painted form requiring a conversion coating to improve the adhesion. Chromate based conversion coating processes are extremely good for these purposes, however the carcinogenic and toxic nature of hexavalent chromium led to the search for more benign and eco......, crystalline nano-particles, role of steam-based treatment on adhesion of industrially applied powder coating, and investigations of a failed painted aluminium window profile due to defects in the extruded profile. Chapters 13 and 14 describe the overall discussion, conclusions and future work based...

Deformation features of aluminium in tensile tests

International Nuclear Information System (INIS)

Quadros, N.F. de.

1984-01-01

It is presented a method to analyse stress-strain curves. Plastic and elastic strains were studied. The strains were done by tensile tests in four types of materials: highly pure aluminium, pure aluminium, commercially pure aluminium and aluminium - uranium. The chemical compositions were obtained by spectroscopy analysis and neutron activation analysis. Tensile tests were carried out at three strain rates, at room temperature, 100,200, 300 and 400 0 C, with knives extensometer and strain-gages to studied the elastic strain region. A multiple spring model based on two springs model to analyse elastic strain caused by tests without extensometers, taking in account moduli of elasticity and, an interactive analysis system with graphic capability were developed. It was suggested a qualitative model to explain the quantized multielasticity of Bell. (M.C.K.) [pt

Particle size distribution of brominated flame retardants in house dust from Japan

Directory of Open Access Journals (Sweden)

Natsuko Kajiwara

2016-06-01

Full Text Available The present study was conducted to examine the concentrations, profiles, and mass distributions of polybrominated diphenyl ethers (PBDEs, hexabromocyclododecanes (HBCDs, and polybrominated dibenzo-p-dioxins/furans (PBDD/Fs based on the particle sizes of house dust samples from five homes in Japan. After removal of impurities from house dust from vacuum cleaner bags, selected indoor dust samples were size fractionated (>2 mm, 1–2 mm, 0.5–1 mm, 250–500 μm, 106–250 μm, 53–106 μm, and 250 μm in size and fluffy dust were included. The conclusion is that particulate dust <250 μm in size without fluffy dust should be used to analyze dust for brominated flame retardants.

Parameterizations for narrowband and broadband albedo of pure snow and snow containing mineral dust and black carbon

Science.gov (United States)

Dang, Cheng; Brandt, Richard E.; Warren, Stephen G.

2015-06-01

The reduction of snow spectral albedo by black carbon (BC) and mineral dust, both alone and in combination, is computed using radiative transfer modeling. Broadband albedo is shown for mass fractions covering the full range from pure snow to pure BC and pure dust, and for snow grain radii from 5 µm to 2500 µm, to cover the range of possible grain sizes on planetary surfaces. Parameterizations are developed for opaque homogeneous snowpacks for three broad bands used in general circulation models and several narrower bands. They are functions of snow grain radius and the mass fraction of BC and/or dust and are valid up to BC content of 10 ppm, needed for highly polluted snow. A change of solar zenith angle can be mimicked by changing grain radius. A given mass fraction of BC causes greater albedo reduction in coarse-grained snow; BC and grain radius can be combined into a single variable to compute the reduction of albedo relative to pure snow. The albedo reduction by BC is less if the snow contains dust, a common situation on mountain glaciers and in agricultural and grazing lands. Measured absorption spectra of mineral dust are critically reviewed as a basis for specifying dust properties for modeling. The effect of dust on snow albedo at visible wavelengths can be represented by an "equivalent BC" amount, scaled down by a factor of about 200. Dust has little effect on the near-IR albedo because the near-IR albedo of pure dust is similar to that of pure snow.

A SUBMILLIMETER CONTINUUM SURVEY OF LOCAL DUST-OBSCURED GALAXIES

International Nuclear Information System (INIS)

Lee, Jong Chul; Hwang, Ho Seong; Lee, Gwang-Ho

2016-01-01

We conduct a 350 μ m dust continuum emission survey of 17 dust-obscured galaxies (DOGs) at z = 0.05–0.08 with the Caltech Submillimeter Observatory (CSO). We detect 14 DOGs with S 350μm = 114–650 mJy and signal-to-noise > 3. By including two additional DOGs with submillimeter data in the literature, we are able to study dust content for a sample of 16 local DOGs, which consist of 12 bump and four power-law types. We determine their physical parameters with a two-component modified blackbody function model. The derived dust temperatures are in the range 57–122 K and 22–35 K for the warm and cold dust components, respectively. The total dust mass and the mass fraction of the warm dust component are 3–34 × 10 7 M ⊙ and 0.03%–2.52%, respectively. We compare these results with those of other submillimeter-detected infrared luminous galaxies. The bump DOGs, the majority of the DOG sample, show similar distributions of dust temperatures and total dust mass to the comparison sample. The power-law DOGs show a hint of smaller dust masses than other samples, but need to be tested with a larger sample. These findings support that the reason DOGs show heavy dust obscuration is not an overall amount of dust content, but probably the spatial distribution of dust therein.

A SUBMILLIMETER CONTINUUM SURVEY OF LOCAL DUST-OBSCURED GALAXIES

Energy Technology Data Exchange (ETDEWEB)

Lee, Jong Chul [Korea Astronomy and Space Science Institute, 776 Daedeokdae-ro, Yuseong-gu, Daejeon 34055 (Korea, Republic of); Hwang, Ho Seong [School of Physics, Korea Institute for Advanced Study, 85 Hoegiro, Dongdaemun-gu, Seoul 02455 (Korea, Republic of); Lee, Gwang-Ho, E-mail: jclee@kasi.re.kr [Department of Physics and Astronomy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742 (Korea, Republic of)

2016-12-20

We conduct a 350 μ m dust continuum emission survey of 17 dust-obscured galaxies (DOGs) at z = 0.05–0.08 with the Caltech Submillimeter Observatory (CSO). We detect 14 DOGs with S{sub 350μm} = 114–650 mJy and signal-to-noise > 3. By including two additional DOGs with submillimeter data in the literature, we are able to study dust content for a sample of 16 local DOGs, which consist of 12 bump and four power-law types. We determine their physical parameters with a two-component modified blackbody function model. The derived dust temperatures are in the range 57–122 K and 22–35 K for the warm and cold dust components, respectively. The total dust mass and the mass fraction of the warm dust component are 3–34 × 10{sup 7} M {sub ⊙} and 0.03%–2.52%, respectively. We compare these results with those of other submillimeter-detected infrared luminous galaxies. The bump DOGs, the majority of the DOG sample, show similar distributions of dust temperatures and total dust mass to the comparison sample. The power-law DOGs show a hint of smaller dust masses than other samples, but need to be tested with a larger sample. These findings support that the reason DOGs show heavy dust obscuration is not an overall amount of dust content, but probably the spatial distribution of dust therein.

Dielectric aluminium phosphate thin films. Couches minces dielectriques de phosphate d'aluminium

Energy Technology Data Exchange (ETDEWEB)

Daviero, S. (Lab. Physicochimie des Materiaux Solides, 34 - Montpellier (France)); Avinens, C. (Lab. Physicochimie des Materiaux Solides, 34 - Montpellier (France)); Ibanez, A. (Lab. Physicochimie des Materiaux Solides, 34 - Montpellier (France)); Giuntini, J.C. (Lab. Physicochimie des Materiaux Solides, 34 -Montpellier (France)); Philippot, E. (Lab. Physicochimie des Materiaux Solides, 34 - Montpellier (France))

1993-04-01

Aluminium phosphate thin films on silicium substrate have been carried out from tributylphosphate and aluminium acetylacetonate precursors in solution through the ''pyrosol'' process. It can be observed a large range of chemical analysis in terms of experimental conditions. These thin films have been characterized by X-ray diffraction and infrared spectrometry. Their electrical characteristics, defined from direct current and alternative current measurements, are quite different to those of the crystallized phosphate and can be explained by P-O and Al-O ''dangling bond'' existence. (orig.).

Intersampler field comparison of Respicon(R), IOM, and closed-face 25-mm personal aerosol samplers during primary production of aluminium.

Science.gov (United States)

Skaugset, Nils Petter; Ellingsen, Dag G; Notø, Hilde; Jordbekken, Lars; Thomassen, Yngvar

2013-10-01

Intersampler field comparison of Respicon(®), 25-mm closed-face 'total dust' cassette (CFC), and IOM inhalable aerosol sampler was conducted in pot rooms at seven aluminium smelters. The aerosol mass and water-soluble fluoride were selected as airborne contaminants for the comparisons. The aerosol masses of 889 sample pairs of IOM and Respicon(®) inhalable aerosol sub-fraction, 165 of IOM and 25-mm CFC, and 194 of CFC and Respicon(®) thoracic aerosol sub-fraction were compared. The number of sample pairs for the comparison of water-soluble fluoride was 906, 170, and 195, respectively. The geometric mean aerosol mass collected with the inhalable Respicon(®) was 2.91 mg m(-3) compared with 3.38 mg m(-3) with the IOM. The overall ratio between IOM and Respicon(®) inhalable sub-fraction was 1.16 [95% confidence interval (CI) = 1.11-1.21] for aerosol mass and 1.13 (95% CI = 1.08-1.18) for water-soluble fluoride. The results indicate that Respicon(®) undersampled the aerosol mass and water-soluble fluoride in the inhalable sub-fraction compared with the IOM. The results indicated undersampling of the Respicon(®) at mass concentrations higher than 1.35 mg m(-3) and oversampling at lower mass concentrations. The overall ratio between aerosol mass collected with IOM and CFC was 4.19 (95% CI = 3.79-4.64) and 1.61 (95% CI = 1.51-1.72) for water-soluble fluoride. Thus, for this industry, a correction factor of 4.2 is suggested for the conversion of CFC to inhalable aerosol masses and a conversion factor of 1.6 for water-soluble fluoride if wall deposits in the CFC are included. CFC and thoracic Respicon(®) collected similar aerosol masses (ratio = 1.04; 95% CI = 0.97-1.12), whereas the ratio was 1.19 (95% CI = 1.11-1.28) for water-soluble fluoride. The variability of the exposure is substantial; thus, large data sets are required in sampler performance field comparisons.

Severe Cardiomyopathy after Huffing Dust-Off™

Directory of Open Access Journals (Sweden)

Alexis L. Cates

2016-01-01

Full Text Available A 34-year-old man was found down in a parking lot after huffing fifteen cans of Dust-Off. Though lucid during the initial hospital evaluation, the patient experienced a generalized seizure followed by a torsades de pointes arrhythmia and was resuscitated. An echocardiogram revealed left and right ventricular dysfunction with an ejection fraction of 25%. This unique outcome of inhalant abuse has scarcely been reported in similar cases. The patient fully recovered and had a normal ejection fraction prior to discharge.

Rapidly solidified aluminium for optical applications

NARCIS (Netherlands)

Gubbels, G.P.H.; Venrooy, B.W.H. van; Bosch, A.J.; Senden, R.

2008-01-01

This paper present the results of a diamond turning study of a rapidly solidified aluminium 6061 alloy grade, known as RSA6061. It is shown that this small grain material can be diamond turned to smaller roughness values than standard AA6061 aluminium grades. Also, the results are nearly as good as

[Determination of aluminium in flour foods with photometric method].

Science.gov (United States)

Ma, Lan; Zhao, Xin; Zhou, Shuang; Yang, Dajin

2012-05-01

To establish a determination method for aluminium in flour foods with photometric method. After samples being treated with microwave digestion and wet digestion, aluminium in staple flour foods was determined by photometric method. There was a good linearity of the result in the range of 0.25 - 5.0 microg/ml aluminium, r = 0.9998; limit of detection (LOD) : 2.3 ng/ml; limit of quantitation (LOQ) : 7 ng/ml. This method of determining aluminium in flour foods is simple, rapid and reliable.

Optimization of the composition and structure of heat-resistant casting aluminium alloys with additions of cerium, iron, nickel and zirconium

International Nuclear Information System (INIS)

Belov, N.A.; Lavrishchev, Yu.V.

2000-01-01

A study is made of the effect of composition and structure on mechanical properties of cast alloys of the Al-Ce-Ni-Fe-Zr system in which binary and ternary eutectics with participation of low alloyed aluminium solid solution and Al 4 Ce, Al 3 Ni and Al 9 FeNi phases are crystallized. It is found that microhardness of eutectics is heavily dependent on the volume fraction of aluminides and their dispersivity. It was shown that essential hardening of aluminium matrix can be achieved at the cost of zirconium additive in quantity of 0.6 % when using two-stage manufacturing operation. Experimental compositions of Al-10 % Ce-5% Ni-0.6 % Zr and Al-1.5 % Fe-1.5 % Ni-0.6 % Zr on the basis of ternary and binary eutectics respectively as billets essentially exceed industrial heat-resistant cast aluminium alloys AK12MMgN and AM5 as to a set of room and high-temperature mechanical properties and hot brittleness index [ru

Comparison of reactivity to a metallic disc and 2% aluminium salt in 366 children, and reproducibility over time for 241 young adults with childhood vaccine-related aluminium contact allergy.

Science.gov (United States)

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

2018-07-01

An aluminium hydroxide-adsorbed pertussis toxoid vaccine was studied in 76 000 children in the 1990s in Gothenburg, Sweden. Long-lasting itchy subcutaneous nodules at the vaccination site were seen in 745 participants. Of 495 children with itchy nodules who were patch tested for aluminium allergy, 377 were positive. In 2007-2008, 241 of the positive children were retested. Only in one third were earlier positive results reproduced. To further describe patch test reactions to different aluminium compounds in children with vaccine-induced aluminium allergy. Positive patch test results for metallic aluminium (empty Finn Chamber) and aluminium chloride hexahydrate 2% petrolatum (pet.) were analysed in 366 children with vaccine-induced persistent itching nodules tested in 1998-2002. Of those, 241 were tested a second time (2007-2008), and the patch test results of the two aluminium preparations were analysed. Patch testing with aluminium chloride hexahydrate 2% pet. is a more sensitive way to diagnose aluminium contact allergy than patch testing with metallic aluminium. A general decrease in the strength of reactions to both aluminium preparations in 241 children tested twice was observed. Aluminium contact allergy can be diagnosed by patch testing without using metallic aluminium. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Airborne desert dust and aeromicrobiology over the Turkish Mediterranean coastline

Science.gov (United States)

Griffin, Dale W.; Kubilay, Nilgün; Kocak, Mustafa; Gray, Mike A.; Borden, Timothy C.; Shinn, Eugene A.

2007-01-01

Between 18 March and 27 October 2002, 220 air samples were collected on 209 of 224 calendar days, on top of a coastal atmospheric research tower in Erdemli, Turkey. The volume of air filtered for each sample was 340 liters. Two hundred fifty-seven bacterial and 2598 fungal colony forming units (CFU) were enumerated from the samples using a low-nutrient agar. Ground-based dust measurements demonstrated that the region is routinely impacted by dust generated regionally and from North Africa and that the highest combined percent recovery of total CFU and African dust deposition occurred in the month of April (93.4% of CFU recovery and 91.1% of dust deposition occurred during African dust days versus no African dust present, for that month). A statistically significant correlation was observed (peak regional African dust months of March, April and May; rs=0.576, P=0.000) between an increase in the prevalence of microorganisms recovered from atmospheric samples on dust days (regional and African as determined by ground-based dust measurements), versus that observed on non-dust days. Given the prevalence of atmospherically suspended desert dust and microorganisms observed in this study, and that culture-based studies typically only recover a small fraction (

Endotoxin and dust at respirable and nonrespirable particle sizes are not consistent between cage- and floor-housed poultry operations.

Science.gov (United States)

Kirychuk, Shelley P; Reynolds, Stephen J; Koehncke, Niels K; Lawson, Joshua; Willson, Philip; Senthilselvan, Ambikaipakan; Marciniuk, Darcy; Classen, Henry L; Crowe, Trever; Just, Natasha; Schneberger, David; Dosman, James A

2010-10-01

Individuals engaged in work in intensive animal houses experience some of the highest rates of occupationally related respiratory symptoms. Organic dust and in particular endotoxin has been most closely associated with respiratory symptoms and lung function changes in workers. It has previously been shown that for intensive poultry operations, type of poultry housing [cage-housed (CH) versus floor-housed (FH)] can influence the levels of environmental contaminants. The goal of the study was to determine the differences in endotoxin and dust levels at different size fractions between CH and FH poultry operations. Fifteen CH and 15 FH poultry operations were sampled for stationary measurements (area) of dust and associated endotoxin. Fractioned samples were collected utilizing Marple cascade impactors. Gravimetric and endotoxin analysis were conducted on each of the filters. When assessed by individual Marple stage, there was significantly greater airborne endotoxin concentration (endotoxin units per cubic meter) in the size fraction >9.8 μm for the FH operations whereas at the size fraction 1.6-3.5 μm, the CH operations had significantly greater airborne endotoxin concentration than the FH operations. Endotoxin concentration in the dust mass (endotoxin units per milligram) was significantly greater in the CH operations as compared to the FH operations for all size fractions >1.6 μm. As such, endotoxin in the respirable fraction accounted for 24% of the total endotoxin in the CH operations whereas it accounted for only 11% in the FH operations. There was significantly more dust in all size fractions in the FH operations as compared to the CH poultry operations. There is more endotoxin in the presence of significantly lower dust levels in the respirable particle size fractions in CH poultry operations as compared to the FH poultry operations. This difference in respirable endotoxin may be important in relation to the differential respiratory response experienced by

Effect of smelt aluminium on mechanical properties of steels

International Nuclear Information System (INIS)

Ryabov, V.R.; Dykhno, I.S.; Deev, G.F.; Karikh, V.V.

1987-01-01

Effect of smelt aluminium on mechanical properties of armco-iron and 12 Kh18N10T steel is studied. It is stated that in smelt aluminium and aluminium alloy contact with armco-iron the sample ductility is decreased. Corrosion effect of smelt alluminium on (18Kh15N5AM3) steel in the form of reinforced wire in aluminium-steel KAS-1A composite material is investigted. It is stated in experiment that during smelt alluminium-steel contact interaction of heterogeneous phases takes place

Study of corrosion in aluminium using neutron radiography technique

International Nuclear Information System (INIS)

Islam, M.N.; Alam, M.K.; Saklayen, M.A.; Ahsan, M.H.; Islam, S.M.A.; Zaman, M.A.

2000-01-01

Neutron radiography technique has been adopted for detection of corrosion in aluminium by filling artificially made holes on aluminium slab with Al(OH) 3 . The contrast between the optical densities of corrosion products and aluminium slab was assessed from the densitometric measurements. Variation of optical density difference with sample thickness has also been studied. The results confirm that approximately 0.039 mm thick corrosion products having diameter 10 mm can easily be detected in 2 cm thick aluminium slab. The linear attenuation coefficient of Al(OH) 3 has been obtained as 0.9447. From the present investigation it is confirmed that film neutron radiography (NR) technique is helpful for investigation of Al(OH) 3 type corrosion product in aluminium. (author)

Effects of aluminium surface morphology and chemical modification on wettability

Energy Technology Data Exchange (ETDEWEB)

Rahimi, M., E-mail: mar@sbi.aau.dk [Department of Energy and Environment, Danish Building Research Institute, Aalborg University, A.C. Meyers Vænge 15, 2450 København SV (Denmark); Fojan, P.; Gurevich, L. [Department of Physics and Nanotechnology, Aalborg University, Skjernvej 4, DK-9220 Aalborg East (Denmark); Afshari, A. [Department of Energy and Environment, Danish Building Research Institute, Aalborg University, A.C. Meyers Vænge 15, 2450 København SV (Denmark)

2014-03-01

Highlights: • Successful surface modification procedures on aluminium samples were performed involving formation of the layer of hydrophilic hyperbranched polyethyleneglycol (PEG) via in situ polymerization, molecular vapour deposition of a monolayer of fluorinated silane, and a combination of those. • The groups of surfaces with hydrophobic behavior were found to follow the Wenzel model. • A transition from Cassie–Baxter's to Wenzel's regime was observed due to changing of the surface roughness upon mechanical polishing in aluminium samples. - Abstract: 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

Spectrophotometric determination of aluminium in steel with xylenol orange

International Nuclear Information System (INIS)

Majeed, A.; Javed, N.; Khan, M.S.

1996-01-01

Spectrophotometric determination of Aluminium in steel based on colour reaction between Aluminium and xylenol orange has been carried out. Red coloured complex formed in weak acidic solution is measured for its absorbance at 550 nm. The various optimum experimental conditions for Aluminium xylenol orange (Al-Xo) complex have been studied. (author)

MULTIGRAIN: a smoothed particle hydrodynamic algorithm for multiple small dust grains and gas

Science.gov (United States)

Hutchison, Mark; Price, Daniel J.; Laibe, Guillaume

2018-05-01

We present a new algorithm, MULTIGRAIN, for modelling the dynamics of an entire population of small dust grains immersed in gas, typical of conditions that are found in molecular clouds and protoplanetary discs. The MULTIGRAIN method is more accurate than single-phase simulations because the gas experiences a backreaction from each dust phase and communicates this change to the other phases, thereby indirectly coupling the dust phases together. The MULTIGRAIN method is fast, explicit and low storage, requiring only an array of dust fractions and their derivatives defined for each resolution element.

Wear behavior of carbon fiber/aluminium-composites during abrasive loading; Verschleissverhalten von Kohlenstoffaser/Aluminium-Verbunden unter abrasiver Beanspruchung

Energy Technology Data Exchange (ETDEWEB)

Wielage, B.; Dorner, A. [Technische Univ. Chemnitz (Germany). Lehrstuhl fuer Verbundwerkstoffe

1998-07-01

Abrasive wear resistance of aluminium is significantly improved by the reinforcement with a high volume percentage of carbon fibres. The wear of unreinforced aluminium after scratching by a diamond indenter can be described as pure microgrooving without any micro-chipping. After integration of 70 vol.-% carbon fibers the damage mechanism is considerably altered and a great amount of micro-chipping occurs. The abrasive wear is strongly influenced by the fiber orientation. The best wear resistance is observed when the fibers are orientated perpendicular to the wear surface. (orig.) [Deutsch] Die Verstaerkung von Aluminium mit einem hohen Volumengehalt endloser Kohlenstoffasern verbessert erkennbar dessen Resistenz gegenueber Abrasionsverschleiss. Der Verschleiss von unverstaerktem Aluminium infolge des Ritzens mit einem Diamantindenter erfolgt in Form von reinem Mikrofurchen ohne Spanbildung. Aufgrund der Integration von 70 Vol.-% Kohlenstoffasern wird eine erhebliche Zunahme des Schaedigungsmechanismus Mikrospanen festgestellt. Die Faserorientierung hat merklichen Einfluss auf die Sensibilitaet gegenueber Abrasion. Orientierung der anisotropen Kohlenstoffasern senkrecht zur Verschleissoberflaeche bedingt den geringsten Abrasionsverschleiss. (orig.)

The effect of organic coating on the heterogeneous ice nucleation efficiency of mineral dust aerosols

Energy Technology Data Exchange (ETDEWEB)

Moehler, O; Benz, S; Saathoff, H; Schnaiter, M; Wagner, R [Forschungszentrum Karlsruhe, Institute for Meteorology and Climate Research, 76021 Karlsruhe (Germany); Schneider, J; Walter, S [Max Planck Institute for Chemistry, 55128 Mainz (Germany); Ebert, V; Wagner, S [University of Heidelberg, Institute for Physical Chemistry, 69120 Heidelberg (Germany)], E-mail: Ottmar.Moehler@imk.fzk.de

2008-04-15

The effect of organic coating on the heterogeneous ice nucleation (IN) efficiency of dust particles was investigated at simulated cirrus cloud conditions in the AIDA cloud chamber of Forschungszentrum Karlsruhe. Arizona test dust (ATD) and the clay mineral illite were used as surrogates for atmospheric dust aerosols. The dry dust samples were dispersed into a 3.7 m{sup 3} aerosol vessel and either directly transferred into the 84 m{sup 3} cloud simulation chamber or coated before with the semi-volatile products from the reaction of {alpha}-pinene with ozone in order to mimic the coating of atmospheric dust particles with secondary organic aerosol (SOA) substances. The ice-active fraction was measured in AIDA expansion cooling experiments as a function of the relative humidity with respect to ice, RHi, in the temperature range from 205 to 210 K. Almost all uncoated dust particles with diameters between 0.1 and 1.0 {mu}m acted as efficient deposition mode ice nuclei at RHi between 105 and 120%. This high ice nucleation efficiency was markedly suppressed by coating with SOA. About 20% of the ATD particles coated with a SOA mass fraction of 17 wt% were ice-active at RHi between 115 and 130%, and only 10% of the illite particles coated with an SOA mass fraction of 41 wt% were ice-active at RHi between 160 and 170%. Only a minor fraction of pure SOA particles were ice-active at RHi between 150 and 190%. Strong IN activation of SOA particles was observed only at RHi above 200%, which is clearly above water saturation at the given temperature. The IN suppression and the shift of the heterogeneous IN onset to higher RHi seem to depend on the coating thickness or the fractional surface coverage of the mineral particles. The results indicate that the heterogeneous ice nucleation potential of atmospheric mineral particles may also be suppressed if they are coated with secondary organics.

The effect of organic coating on the heterogeneous ice nucleation efficiency of mineral dust aerosols

International Nuclear Information System (INIS)

Moehler, O; Benz, S; Saathoff, H; Schnaiter, M; Wagner, R; Schneider, J; Walter, S; Ebert, V; Wagner, S

2008-01-01

The effect of organic coating on the heterogeneous ice nucleation (IN) efficiency of dust particles was investigated at simulated cirrus cloud conditions in the AIDA cloud chamber of Forschungszentrum Karlsruhe. Arizona test dust (ATD) and the clay mineral illite were used as surrogates for atmospheric dust aerosols. The dry dust samples were dispersed into a 3.7 m 3 aerosol vessel and either directly transferred into the 84 m 3 cloud simulation chamber or coated before with the semi-volatile products from the reaction of α-pinene with ozone in order to mimic the coating of atmospheric dust particles with secondary organic aerosol (SOA) substances. The ice-active fraction was measured in AIDA expansion cooling experiments as a function of the relative humidity with respect to ice, RHi, in the temperature range from 205 to 210 K. Almost all uncoated dust particles with diameters between 0.1 and 1.0 μm acted as efficient deposition mode ice nuclei at RHi between 105 and 120%. This high ice nucleation efficiency was markedly suppressed by coating with SOA. About 20% of the ATD particles coated with a SOA mass fraction of 17 wt% were ice-active at RHi between 115 and 130%, and only 10% of the illite particles coated with an SOA mass fraction of 41 wt% were ice-active at RHi between 160 and 170%. Only a minor fraction of pure SOA particles were ice-active at RHi between 150 and 190%. Strong IN activation of SOA particles was observed only at RHi above 200%, which is clearly above water saturation at the given temperature. The IN suppression and the shift of the heterogeneous IN onset to higher RHi seem to depend on the coating thickness or the fractional surface coverage of the mineral particles. The results indicate that the heterogeneous ice nucleation potential of atmospheric mineral particles may also be suppressed if they are coated with secondary organics

Control of dust production in ITER

International Nuclear Information System (INIS)

Rodriguez-Rodrigo, L.; Ciattaglia, S.; Elbez-Uzan, J.

2006-01-01

In the last years dust has been observed in a number of fusion devices and is being studied more in detail for understanding in particular the physical phenomena related to its formation, its composition, physical and chemical characteristics, and the amount of produced dust. The extrapolation of dust formation to ITER predicts (with large error bars), a large mass of dust production with a scattered size distribution. To evaluate the impact of dust on safety, assumptions have also been made on radionuclide inventory, and mobility in off-normal events, as well as any postulated contributions the dust may make to effluents or accidental releases. Solid activation products in structures are generally not readily mobilisable in incidental and accidental situations, so that activated dust, tritium and activated corrosions products are the important in-vessel source terms in postulated scenarios that assume a mobilisation and release of some fraction of this inventory. Such a release would require the simultaneous leak or bypass of several robust confinement barriers. Further concerns for dust may be the potential for chemical reactions between dust and coolant in the event of an in-vessel leak, and the theoretical possibility of a dust explosion, either of which could in principle cause a pressure rise that challenges one or more of the confinement barriers. Although these hazards can - and will - be controlled by other measures in the ITER design, application of the principle of Defence in Depth dictates that the dust inventory should also be minimised and controlled to prevent the potential hazard. A well-coordinated R-and-D programme is required to support this dust production control. This document provides from the safety point of view, an overview of existing data given in '' Dossier d'Options de Surete '', the first safety report presented in 2001 to the French Safety Authorities, and ITER documents; it also gathers information on status of studies on activated

Study of ionic movements during anodic oxidation of nitrogen-implanted aluminium

International Nuclear Information System (INIS)

Terwagne, G.; Lucas, S.; Bodart, F.; Sorensen, G.; Jensen, H.

1990-01-01

In recent years there has been a considerable interest in synthesizing aluminium nitrides by ion implantation in order to modify the tribological properties of aluminium. The growth of an oxide layer by anodic process on these synthesized aluminium nitrides gives an interesting oxide-on-semiconductor material with surprising dynamic and decorative properties. During the anodic oxidation, ionic movements are involved in the near-surface region of the aluminium material; these ionic movements have been studied by Rutherford backscattering spectrometry (RBS) and nuclear reaction analysis (NRA) on thin aluminium foils (7000 A) preimplanted with nitrogen and post-oxidized in an ammonium pentaborate solution. The growth of the oxide layer is reduced when the aluminium is preimplanted with nitrogen: the speed of oxidation depends on the implantation conditions (energy and fluence). Moreover, the aluminium nitride can be dissolved when all metallic aluminium staying between the surface and the AlN are consumed by the anodic process. (orig.)

The Physics of Protoplanetesimal Dust Agglomerates. IX. Mechanical Properties of Dust Aggregates Probed by a Solid-projectile Impact

Science.gov (United States)

Katsuragi, Hiroaki; Blum, Jürgen

2017-12-01

Dynamic characterization of mechanical properties of dust aggregates has been one of the most important problems to quantitatively discuss the dust growth in protoplanetary disks. We experimentally investigate the dynamic properties of dust aggregates by low-speed (≤slant 3.2 m s-1) impacts of solid projectiles. Spherical impactors made of glass, steel, or lead are dropped onto a dust aggregate with a packing fraction of ϕ = 0.35 under vacuum conditions. The impact results in cratering or fragmentation of the dust aggregate, depending on the impact energy. The crater shape can be approximated by a spherical segment and no ejecta are observed. To understand the underlying physics of impacts into dust aggregates, the motion of the solid projectile is acquired by a high-speed camera. Using the obtained position data of the impactor, we analyze the drag-force law and dynamic pressure induced by the impact. We find that there are two characteristic strengths. One is defined by the ratio between impact energy and crater volume and is ≃120 kPa. The other strength indicates the fragmentation threshold of dynamic pressure and is ≃10 kPa. The former characterizes the apparent plastic deformation and is consistent with the drag force responsible for impactor deceleration. The latter corresponds to the dynamic tensile strength to create cracks. Using these results, a simple model for the compaction and fragmentation threshold of dust aggregates is proposed. In addition, the comparison of drag-force laws for dust aggregates and loose granular matter reveals the similarities and differences between the two materials.

Technical note: Mineralogical, chemical, morphological, and optical interrelationships of mineral dust re-suspensions

Directory of Open Access Journals (Sweden)

J. P. Engelbrecht

2016-08-01

Full Text Available This paper promotes an understanding of the mineralogical, chemical, and physical interrelationships of re-suspended mineral dusts collected as grab samples from global dust sources. Surface soils were collected from arid regions, including the southwestern USA, Mali, Chad, Morocco, Canary Islands, Cabo Verde, Djibouti, Afghanistan, Iraq, Kuwait, Qatar, UAE, Serbia, China, Namibia, Botswana, Australia, and Chile. The  <  38 µm sieved fraction of each sample was re-suspended in a chamber, from which the airborne mineral dust could be extracted, sampled, and analyzed. Instruments integrated into the entrainment facility included two PM10 and two PM2.5 filter samplers, a beta attenuation gauge for the continuous measurement of PM10 and PM2.5 particulate mass fractions, an aerodynamic particle size analyzer, and a three-wavelength (405, 532, 781 nm photoacoustic instrument with integrating reciprocal nephelometer for monitoring absorption and scattering coefficients during the dust re-suspension process. Filter sampling media included Teflon® membrane and quartz fiber filters for chemical analysis and Nuclepore® filters for individual particle analysis by scanning electron microscopy (SEM. The  <  38 µm sieved fractions were also analyzed by X-ray diffraction for their mineral content while the  >  75,  <  125 µm soil fractions were mineralogically assessed by optical microscopy. Presented here are results of the optical measurements, showing the interdependency of single-scattering albedos (SSA at three different wavelengths and mineralogical content of the entrained dust samples. To explain the elevated concentrations of iron (Fe and Fe ∕ Al ratios in the soil re-suspensions, we propose that dust particles are to a large extent composed of nano-sized particles of micas, clays, metal oxides, and ions of potassium (K+, calcium (Ca2+, and sodium (Na+ evenly dispersed as a colloid or adsorbed in amorphous

Aluminium recovery from waste incineration bottom ash, and its oxidation level.

Science.gov (United States)

Biganzoli, Laura; Grosso, Mario

2013-09-01

The recovery of aluminium (Al) scraps from waste incineration bottom ash is becoming a common practice in waste management. However, during the incineration process, Al in the waste undergoes oxidation processes that reduce its recycling potential. This article investigates the behaviour of Al scraps in the furnace of two selected grate-fired waste-to-energy plants and the amount recoverable from the bottom ash. About 21-23% of the Al fed to the furnace with the residual waste was recovered and potentially recycled from the bottom ash. Out of this amount, 76-87% was found in the bottom ash fraction above 5 mm and thus can be recovered with standard eddy current separation technology. These values depend on the characteristics and the mechanical strength of the Al items in the residual waste. Considering Al packaging materials, about 81% of the Al in cans can be recovered from the bottom ash as an ingot, but this amount decreases to 51% for trays, 27% for a mix of aluminium and poly-laminated foils and 47% for paper-laminated foils. This shows that the recovery of Al from the incineration residues increases proportionally to the thickness of the packaging.

Steam Assisted Accelerated Growth of Oxide Layer on Aluminium Alloys

DEFF Research Database (Denmark)

Din, Rameez Ud; Yuksel, Serkan; Jellesen, Morten Stendahl

2013-01-01

Corrosion resistance of aluminium alloys is related to the composition and morphology of the oxide film on the surface of aluminium. In this paper we investigated the use of steam on the surface modification of aluminium to produce boehmite films. The study reveals a detailed investigation...... of the effect of vapour pressure, structure of intermetallic particles and thickness of boehmite films on the corrosion behaviour of aluminium alloys....

Sahara Dust Cloud

Science.gov (United States)

2005-01-01

[figure removed for brevity, see original site] Dust Particles Click on the image for Quicktime movie from 7/15-7/24 A continent-sized cloud of hot air and dust originating from the Sahara Desert crossed the Atlantic Ocean and headed towards Florida and the Caribbean. A Saharan Air Layer, or SAL, forms when dry air and dust rise from Africa's west coast and ride the trade winds above the Atlantic Ocean. These dust clouds are not uncommon, especially during the months of July and August. They start when weather patterns called tropical waves pick up dust from the desert in North Africa, carry it a couple of miles into the atmosphere and drift westward. In a sequence of images created by data acquired by the Earth-orbiting Atmospheric Infrared Sounder ranging from July 15 through July 24, we see the distribution of the cloud in the atmosphere as it swirls off of Africa and heads across the ocean to the west. Using the unique silicate spectral signatures of dust in the thermal infrared, AIRS can detect the presence of dust in the atmosphere day or night. This detection works best if there are no clouds present on top of the dust; when clouds are present, they can interfere with the signal, making it much harder to detect dust as in the case of July 24, 2005. In the Quicktime movie, the scale at the bottom of the images shows +1 for dust definitely detected, and ranges down to -1 for no dust detected. The plots are averaged over a number of AIRS observations falling within grid boxes, and so it is possible to obtain fractional numbers. [figure removed for brevity, see original site] Total Water Vapor in the Atmosphere Around the Dust Cloud Click on the image for Quicktime movie The dust cloud is contained within a dry adiabatic layer which originates over the Sahara Desert. This Saharan Air Layer (SAL) advances Westward over the Atlantic Ocean, overriding the cool, moist air nearer the surface. This burst of very dry air is visible in the AIRS retrieved total water

Corrosion behaviour of borated aluminium used as neutron absorber

Energy Technology Data Exchange (ETDEWEB)

Emmerich, R. [EaglePicher Technologies GmbH, Oehringen (Germany); Ensinger, W.; Enders, B. [Philipps-Univ. of Marburg, Dept. of Chemistry, Material Science Centre (Germany)

2004-07-01

The electrochemical behaviour of pure and borated aluminium was examined. Measurements were performed in two different electrolytes at 90 C containing different trace-amounts of chloride. For borated aluminium current transients, i.e. metastable depassivation events were found. It is suggested to attribute these transients to less stable passivation layers in comparison to pure aluminium.

Role of dust alkalinity in acid mobilization of iron

Directory of Open Access Journals (Sweden)

A. Ito

2010-10-01

Full Text Available Atmospheric processing of mineral aerosols by acid gases (e.g., SO₂, HNO₃, N₂O₅, and HCl may play a key role in the transformation of insoluble iron (Fe in the oxidized or ferric (III form to soluble forms (e.g., Fe(II, inorganic soluble species of Fe(III, and organic complexes of iron. On the other hand, mineral dust particles have a potential of neutralizing the acidic species due to the alkaline buffer ability of carbonate minerals (e.g., CaCO₃ and MgCO₃. Here we demonstrate the impact of dust alkalinity on the acid mobilization of iron in a three-dimensional aerosol chemistry transport model that includes a mineral dissolution scheme. In our model simulations, most of the alkaline dust minerals cannot be entirely consumed by inorganic acids during the transport across the North Pacific Ocean. As a result, the inclusion of alkaline compounds in aqueous chemistry substantially limits the iron dissolution during the long-range transport to the North Pacific Ocean: only a small fraction of iron (<0.2% dissolves from hematite in the coarse-mode dust aerosols with 0.45% soluble iron initially. On the other hand, a significant fraction of iron (1–2% dissolves in the fine-mode dust aerosols due to the acid mobilization of the iron-containing minerals externally mixed with carbonate minerals. Consequently, the model quantitatively reproduces higher iron solubility in smaller particles as suggested by measurements over the Pacific Ocean. It implies that the buffering effect of alkaline content in dust aerosols might help to explain the inverse relationship between aerosol iron solubility and particle size. We also demonstrate that the iron solubility is sensitive to the chemical specification of iron-containing minerals in dust. Compared with the dust sources, soluble iron from combustion sources contributes to a relatively marginal effect for deposition of soluble iron over the North

Effects of Aluminium Sulfate on Cadmium Accumulation in Rice

International Nuclear Information System (INIS)

Khamvarn, Vararas; Boontanon, Narin; Prapagdee, Benjaphorn; Kumsopa, Acharaporn; Boonsirichai, Kanokporn

2011-06-01

Full text: Cadmium accumulation in Pathum Thani 1 and Suphan Buri 60 rice cultivars was investigated upon treatment with aluminium sulfate as a precipitant. Rice was grown hydroponically in a medium containing 4 ppm cadmium nitrate with or without 4 ppm aluminium sulfate. Root, stem with leaves and grain samples were collected and analyzed for cadmium content using atomic absorption spectroscopy and inductively coupled plasma atomic emission spectroscopy. Without the addition of aluminium sulfate, Pathum Thani 1 and Suphan Buri 60 accumulated 24.71∫ 3.14 ppm and 34.43 ∫ 4.51 ppm (dry weight of whole plant) of cadmium, respectively. With aluminium sulfate, cadmium accumulation increased to 40.66 ∫ 2.47 ppm and 62.94 ∫ 10.69 ppm, respectively. The addition of aluminium sulfate to the planting medium did not reduce cadmium accumulation but caused the rice to accumulate more cadmium especially in the shoots and grains. This observation might serve as the basis for future research on the management of agricultural areas that are contaminated with cadmium and aluminium

Electron Conditioning of Technical Aluminium Surfaces

Energy Technology Data Exchange (ETDEWEB)

Le Pimpec, F

2004-09-02

The effect of electron conditioning on commercially aluminium alloys 1100 and 6063 were investigated. Contrary to the assumption that electron conditioning, if performed long enough, can reduce and stabilize the SEY to low values (= 1.3, value of many pure elements [1]), the SEY of aluminium did not go lower than 1.8. In fact, it reincreases with continued electron exposure dose.

Feasibility of fractionating MIBI cold kits for cost reduction

Energy Technology Data Exchange (ETDEWEB)

Penglis, S.; Tsopelas, C. [Royal Adelaide Hospital. SA (Australia)

1998-06-01

Full text: Recently {sup 99m}Tc-MIBI become the first 99mTc-labelled myocardial perfusion imaging agent commercially available in Australia. After labelling each vial is sufficient for three to four patient doses. However, it becomes very expensive when only a single patient dose is required (up to $350 per dose). Our goal in this study was to subdivide the MIBI kit into fractions to establish the stability of these split kits. If successful, this would reduce the expense and make the product more cost-effective. After dissolving the Iyophilised ingredients of a MIBI vial with 5 mL of N2-purged normal saline, 1 mL aliquots of the resultant solution were dispensed into N2-filled vials under aseptic conditions. The vials were then stored frozen at -70 deg C. 99mTc-MIBI was prepared by the addition of 2 GBq of {sup 99m}Tc-pertechnetate in I mL of normal saline to the fractionated kit, followed by heating at 100 deg C for 10 minutes at 0, 2, 4 and 8 weeks post-fractionation. The product was allowed to cool before testing for radiochemical purity (RCP) for up to six hours post-labelling. The RCP of each vial was determined using aluminium oxide coated aluminium TLC strips (Merck) run in 100% ethanol. Over the eight-week evaluation period RCP was maintained at 94.2 + 1.3% over six hours (n = 16), which is greater than the minimum recommended RCP (90%) for patient use. These results show that fractionation of MIBI cold kits and sub-frozen storage under an N{sub 2} atmosphere provides a stable and economical multidose product. Using this method the cost of a single patient dose can be reduced considerably from $350, even allowing for the labour involved in the fractionation

Feasibility of fractionating MIBI cold kits for cost reduction

International Nuclear Information System (INIS)

Penglis, S.; Tsopelas, C.

1998-01-01

Full text: Recently 99m Tc-MIBI become the first 99mTc-labelled myocardial perfusion imaging agent commercially available in Australia. After labelling each vial is sufficient for three to four patient doses. However, it becomes very expensive when only a single patient dose is required (up to $350 per dose). Our goal in this study was to subdivide the MIBI kit into fractions to establish the stability of these split kits. If successful, this would reduce the expense and make the product more cost-effective. After dissolving the Iyophilised ingredients of a MIBI vial with 5 mL of N2-purged normal saline, 1 mL aliquots of the resultant solution were dispensed into N2-filled vials under aseptic conditions. The vials were then stored frozen at -70 deg C. 99mTc-MIBI was prepared by the addition of 2 GBq of 99m Tc-pertechnetate in I mL of normal saline to the fractionated kit, followed by heating at 100 deg C for 10 minutes at 0, 2, 4 and 8 weeks post-fractionation. The product was allowed to cool before testing for radiochemical purity (RCP) for up to six hours post-labelling. The RCP of each vial was determined using aluminium oxide coated aluminium TLC strips (Merck) run in 100% ethanol. Over the eight-week evaluation period RCP was maintained at 94.2 + 1.3% over six hours (n = 16), which is greater than the minimum recommended RCP (90%) for patient use. These results show that fractionation of MIBI cold kits and sub-frozen storage under an N 2 atmosphere provides a stable and economical multidose product. Using this method the cost of a single patient dose can be reduced considerably from $350, even allowing for the labour involved in the fractionation

Integrated spatiotemporal characterization of dust sources and outbreaks in Central and East Asia

Science.gov (United States)

Darmenova, Kremena T.

The potential of atmospheric dust aerosols to modify the Earth's environment and climate has been recognized for some time. However, predicting the diverse impact of dust has several significant challenges. One is to quantify the complex spatial and temporal variability of dust burden in the atmosphere. Another is to quantify the fraction of dust originating from human-made sources. This thesis focuses on the spatiotemporal characterization of sources and dust outbreaks in Central and East Asia by integrating ground-based data, satellite multisensor observations, and modeling. A new regional dust modeling system capable of operating over a span of scales was developed. The modeling system consists of a dust module DuMo, which incorporates several dust emission schemes of different complexity, and the PSU/NCAR mesoscale model MM5, which offers a variety of physical parameterizations and flexible nesting capability. The modeling system was used to perform for the first time a comprehensive study of the timing, duration, and intensity of individual dust events in Central and East Asia. Determining the uncertainties caused by the choice of model physics, especially the boundary layer parameterization, and the dust production scheme was the focus of our study. Implications to assessments of the anthropogenic dust fraction in these regions were also addressed. Focusing on Spring 2001, an analysis of routine surface meteorological observations and satellite multi-sensor data was carried out in conjunction with modeling to determine the extent to which integrated data set can be used to characterize the spatiotemporal distribution of dust plumes at a range of temporal scales, addressing the active dust sources in China and Mongolia, mid-range transport and trans-Pacific, long-range transport of dust outbreaks on a case-by-case basis. This work demonstrates that adequate and consistent characterization of individual dust events is central to establishing a reliable

Aluminium leaching from red mud by filamentous fungi.

Science.gov (United States)

Urík, Martin; Bujdoš, Marek; Milová-Žiaková, Barbora; Mikušová, Petra; Slovák, Marek; Matúš, Peter

2015-11-01

This contribution investigates the efficient and environmentally friendly aluminium leaching from red mud (bauxite residue) by 17 species of filamentous fungi. Bioleaching experiments were examined in batch cultures with the red mud in static, 7-day cultivation. The most efficient fungal strains in aluminium bioleaching were Penicillium crustosum G-140 and Aspergillus niger G-10. The A. niger G-10 strain was capable to extract up to approximately 141 mg·L(-1) of aluminium from 0.2 g dry weight red mud. Chemical leaching with organic acids mixture, prepared according to A. niger G-10 strain's respective fungal excretion during cultivation, proved that organic acids significantly contribute to aluminium solubilization from red mud. Copyright © 2015 Elsevier Inc. All rights reserved.

Determination of ultratrace amounts of uranium and thorium in aluminium and aluminium alloys by electrothermal vaporization/ICP-MS

International Nuclear Information System (INIS)

Nakamura, Yasushi; Kobayashi, Yoshio; Kakurai, Yousuke

1993-01-01

A method has been developed for determining the 0.01 ng g -1 level of uranium and thorium in aluminium and aluminium alloys by electrothermal vaporization (ETV)/ICP-MS. This method was found to be significantly interfered with any matrices or other elements contained. An ion-exchange technique was therefore applied to separate uranium and thorium from aluminium and other elements. It was known that uranium are adsorbed on an anion-exchange resin and thorium are adsorbed on cation-exchange resin. However, aluminium and copper were eluted with 6 M hydrochloric acid. Dissolve the sample with hydrochloric acid containing copper which was added for analysis of pure aluminium, and oxidize with hydrogen peroxide. Concentration of hydrochloric acid in the solution was adjusted to 6 M, and then passed the solution through the mixed ion-exchange resin column. After the uranium and thorium were eluted with 1 M hydrofluoric acid-0.1 M hydrochloric acid, the solution was evaporated to dryness. It was then dissolved with 1 M hydrochloric acid. Uranium and thorium were analyzed by ETV/ICP-MS using tungsten and molybdenum boats, respectively, since the tungsten boat contained high-level thorium and the molybdenum boat contained uranium. The determination limit of uranium and thorium were 0.003 and 0.005 ng g -1 , respectively. (author)

Phosphorus speciation and solubility in aeolian dust deposited in the interior American West

Science.gov (United States)

Zhang, Zhuojun; Goldstein, Harland L.; Reynolds, Richard L.; Hu, Yongfeng; Wang, Xiaoming; Zhu, Mengqiang

2018-01-01

Aeolian dust is a significant source of phosphorus (P) to alpine oligotrophic lakes, but P speciation in dust and source sediments and its release kinetics to lake water remain unknown. Phosphorus K-edge XANES spectroscopy shows that calcium-bound P (Ca−P) is dominant in 10 of 12 dust samples (41−74%) deposited on snow in the central Rocky Mountains and all 42 source sediment samples (the fine fraction) (68−80%), with a lower proportion in dust probably because acidic snowmelt dissolves some Ca−P in dust before collection. Iron-bound P (Fe−P, ∼54%) dominates in the remaining two dust samples. Chemical extractions (SEDEX) on these samples provide inaccurate results because of unselective extraction of targeted species and

Investigations concerning the effect of aluminium toxicity on the physiology and fine structures of oat plants. Physiologische und feinstrukturelle Untersuchungen zur Aluminium-Toxizitaet an Haferpflanzen

Energy Technology Data Exchange (ETDEWEB)

Marienfeld, S.

1992-06-30

In order to test the toxicity of aluminium to plants, two-week-old oat seedlings were exposed to aluminium concentrations of 0-400 [mu]M in the culture broth. Already after 12-24 hours a decrease in longitudinal root growth is to be noted, resulting from impaired mitosis activity of the root tip. This, and the observed premature cell differentiation are not aluminium-specific but unspecific reactions to unfavourable conditions. Shoot growth is only reduced after 3-4 days, and less so. Magnesium and calcium fertilization did enhance the growth of aluminium-stressed plants, but not to the level of the control plants, although the mineral concentration in the leaves reached normal values. Phosphate concentration in the root increased because of aluminium phosphate precipitation in the cell walls, which has detoxifying effect along with aluminium fixation to negative charges in the cell walls. Aluminium remains almost quantitatively in the cell wall area of the roots and is not accumulated in the cell core. Aluminium stress causes transpiration and CO[sub 2] uptake to be impaired as a reaction to the growth depression in the root area, even before the mineral concentration in the shoots is lowered. Later there follow chlorophyll depletion, chloroplast degradation, and a reduction of the leaf area. (UWA)

Friction stir welding (FSW of aluminium foam sandwich panels

Directory of Open Access Journals (Sweden)

M. Bušić

2016-07-01

Full Text Available The article focuses on the influence of welding speed and tool tilt angle upon the mechanical properties at the friction stir welding of aluminium foam sandwich panels. Double side welding was used for producing butt welds of aluminium sandwich panels applying insertion of extruded aluminium profile. Such insertion provided lower pressure of the tool upon the aluminium panels, providing also sufficient volume of the material required for the weldment formation. Ultimate tensile strength and flexural strength for three-point bending test have been determined for samples taken from the welded joints. Results have confirmed anticipated effects of independent variables.

Surface treatments for aluminium alloys

Science.gov (United States)

Ardelean, M.; Lascău, S.; Ardelean, E.; Josan, A.

2018-01-01

Typically, in contact with the atmosphere, the aluminium surface is covered with an aluminium oxide layer, with a thickness of less than 1-2μm. Due to its low thickness, high porosity and low mechanical strength, this layer does not protect the metal from corrosion. Anodizing for protective and decorative purposes is the most common method of superficial oxidation processes and is carried out through anodic oxidation. The oxide films, resulted from anodizing, are porous, have a thickness of 20-50μm, and are heat-resistant, stable to water vapour and other corrosion agents. Hard anodizing complies with the same obtains principles as well as decorative and protective anodization. The difference is in that hard anodizing is achieved at low temperatures and high intensity of electric current. In the paper are presented the results of decorative and hard anodization for specimens made from several aluminium alloys in terms of the appearance of the specimens and of the thickness of the anodized.

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

Directory of Open Access Journals (Sweden)

E. D. Wannaz

2012-01-01

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

Aluminium allergy and granulomas induced by vaccinations for children

DEFF Research Database (Denmark)

Andersen, Rosa Marie O; Zachariae, Claus; Johansen, Jeanne Duus

2014-01-01

Vaccination with aluminium-adsorbed vaccines can induce aluminium allergy with persistent itching subcutaneous nodules at the injection site - vaccination granulomas. In this article we give an overview of childhood aluminium-adsorbed vaccines available in Denmark. Through literature studies we...... examine the incidence, the symptoms and the prognosis for the vaccination granulomas and the allergy. Finally we discuss the status in Denmark....

Hot workability of aluminium alloys

International Nuclear Information System (INIS)

Yoo, Yeon Chul; Oh, Kyung Jin

1986-01-01

Hot Workability of aluminium alloys, 2024, 6061 and 7075, has been studied by hot torsion tests at temperatures from 320 to 515 deg C and at strain rates from 1.26 x 10 -3 to 5.71 x 10 -3 sec -1 . Hot working condition of these aluminium alloys was determined quantitatively from the constitutive equations obtained from flow stress curves in torsion. Experimental data of the logarith of the Zener-Hollomonn parameter showed good linear relationships to the logarith of sinh(ασ-bar)

Sequential heavy metal extraction from dust precipitates and road sediments. Part 2. Sequential heavy metal extraction from urban dust; Sequentielle Schwermetallextraktion aus Staubniederschlaegen und Strassensedimenten. T. 2. Sequentielle Schwermetallextraktion von staedtischen Staeuben

Energy Technology Data Exchange (ETDEWEB)

Heiser, U.; Norra, S.; Stueben, D.; Wagner, M. von [Karlsruhe Univ. (T.H.) (Germany). Inst. fuer Petrographie und Geochemie

1999-03-01

For the application of our method for the sequential extraction of heavy metals from microsamples presented in part 1 (`Sequentielle Schwermetallextraktion von Mikroproben` - `Sequential Extraction of Heavy Metals from Micro Samples`) an investigation was carried out to evaluate airborne dust fallout and street sediments at two urban sites where different heavy metal immission rates occur due to traffic influence. In the street sediments the total concentrations of zinc, copper and lead was three to fivefold higher in the silt and clay fraction (<63 {mu}m) than in the particle size fraction (<1,12 mm), but showed nearly the same mobilisation behaviour. The dust samples showed equal mobilisation behaviour as the street sediments for copper and lead, while zinc was considerably more mobile in the dust samples: In extraction steps I-IV (I: mobile fraction; II: easily deliverable fraction; III: fraction bound to manganese oxides; IV: fraction bound organic to matter) zinc, copper and lead in street sediments, as well as copper and lead in dust samples, were dissolved to 40-70%, whereas about 80% of zinc in the dust samples was already dissolved in extraction step I. (orig.) [Deutsch] Mit Hilfe des in Teil 1 (`Sequentielle Schwermetallextraktion von Mikroproben`) vorgestellten Verfahrens zur sequentiellen Schwermetallextraktion von Mikroproben wurden die Mobilisierbarkeiten von Zink, Kupfer und Blei aus Staubniederschlaegen und aus der Schluff- und Tonfraktion von Strassensedimenten an zwei urbanen Standorten mit unterschiedlicher, verkehrsbedingter Schwermetallbelastung untersucht und miteinander verglichen. In Strassensedimenten wiesen Zink, Kupfer und Blei in der Schluff- und Tonfraktion drei- bis fuenffach hoehere Gesamtgehalte auf als die Korngroessenfraktion <1,12 mm, zeigten aber aehnliches Verhalten in der Mobilisierbarkeit. Bei den Staubproben war die Mobilisierbarkeit von Kupfer und Blei aehnlich wie in den Strassensedimenten, waehrend sich Zink als erheblich

Grain Size Distribution and Health Risk Assessment of Metals in Outdoor Dust in Chengdu, Southwestern China.

Science.gov (United States)

Chen, Mengqin; Pi, Lu; Luo, Yan; Geng, Meng; Hu, Wenli; Li, Zhi; Su, Shijun; Gan, Zhiwei; Ding, Sanglan

2016-04-01

A total of 27 outdoor dust samples from roads, parks, and high spots were collected and analyzed to investigate the contamination of 11 metals (Cr, Mn, Co, Ni, Cu, Zn, As, Sr, Cd, Sb, and Pb) in Chengdu, China. The results showed that the samples from the high spots exhibited the highest heavy metal level compared with those from the roads and the parks, except for Ni, Cu, and Pb. The dust was classified into five grain size fractions. The mean loads of each grain size fraction of 11 determined metals displayed similar distribution, and the contribution of median size (63-125, 125-250, 250-500 μm) fractions accounted for more than 70% of overall heavy metal loads. The health risk posed by the determined metals to human via dust ingestion, dermal contact, and inhalation was investigated. Oral and respiratory bioaccessible parts of the metals in dust were extracted using simulated stomach solution and composite lung serum. The mean bioaccessibilities of 11 investigated metals in the gastric solution were much higher than those in the composite lung serum, especially Zn, Cd, and Pb. Ingestion was the most important exposure pathway with percentage greater than 70% for both children and adults. Risk evaluation results illustrated that children in Chengdu might suffer noncarcinogenic risk when exposed to outdoor dust. Given that the cancer risk values of Pb and Cr larger than 1 × 10(-4), potential carcinogenic risk might occur for Chengdu residents through outdoor dust intake.

Aluminium toxicity tolerance in crop plants: Present status of research

African Journals Online (AJOL)

... tolerance of which genes of the Aluminium-activated malate transporter (ALMT) and multidrug and toxic compound extrusion (MATE) families are prominent. In this review, the progress of research in identifying aluminium toxicity tolerant genes is discussed. Keywords: Aluminium toxicity, soil acidity, hydroponic screening, ...

Global dust sources detection using MODIS Deep Blue Collection 6 aerosol products

Science.gov (United States)

Pérez García-Pando, C.; Ginoux, P. A.

2015-12-01

Our understanding of the global dust cycle is limited by a dearth of information about dust sources, especially small-scale features which could account for a large fraction of global emissions. Remote sensing sensors are the most useful tool to locate dust sources. These sensors include microwaves, visible channels, and lidar. On the global scale, major dust source regions have been identified using polar orbiting satellite instruments. The MODIS Deep Blue algorithm has been particularly useful to detect small-scale sources such as floodplains, alluvial fans, rivers, and wadis , as well as to identify anthropogenic sources from agriculture. The recent release of Collection 6 MODIS aerosol products allows to extend dust source detection to the entire land surfaces, which is quite useful to identify mid to high latitude dust sources and detect not only dust from agriculture but fugitive dust from transport and industrial activities. This presentation will overview the advantages and drawbacks of using MODIS Deep Blue for dust detection, compare to other instruments (polar orbiting and geostationary). The results of Collection 6 with a new dust screening will be compared against AERONET. Applications to long range transport of anthropogenic dust will be presented.

Compressive Behaviour and Energy Absorption of Aluminium Foam Sandwich

Science.gov (United States)

Endut, N. A.; Hazza, M. H. F. Al; Sidek, A. A.; Adesta, E. T. Y.; Ibrahim, N. A.

2018-01-01

Development of materials in automotive industries plays an important role in order to retain the safety, performance and cost. Metal foams are one of the idea to evolve new material in automotive industries since it can absorb energy when it deformed and good for crash management. Recently, new technology had been introduced to replace metallic foam by using aluminium foam sandwich (AFS) due to lightweight and high energy absorption behaviour. Therefore, this paper provides reliable data that can be used to analyze the energy absorption behaviour of aluminium foam sandwich by conducting experimental work which is compression test. Six experiments of the compression test were carried out to analyze the stress-strain relationship in terms of energy absorption behavior. The effects of input variables include varying the thickness of aluminium foam core and aluminium sheets on energy absorption behavior were evaluated comprehensively. Stress-strain relationship curves was used for energy absorption of aluminium foam sandwich calculation. The result highlights that the energy absorption of aluminium foam sandwich increases from 12.74 J to 64.42 J respectively with increasing the foam and skin thickness.

Investigation of different anode materials for aluminium rechargeable batteries

Science.gov (United States)

Muñoz-Torrero, David; Leung, Puiki; García-Quismondo, Enrique; Ventosa, Edgar; Anderson, Marc; Palma, Jesús; Marcilla, Rebeca

2018-01-01

In order to shed some light into the importance of the anodic reaction in reversible aluminium batteries, we investigate here the electrodeposition of aluminium in an ionic liquid electrolyte (BMImCl-AlCl3) using different substrates. We explore the influence of the type of anodic material (aluminium, stainless steel and carbon) and its 3D geometry on the reversibility of the anodic reaction by cyclic voltammetry (CV) and galvanostatic charge-discharge. The shape of the CVs confirms that electrodeposition of aluminium was feasible in the three materials but the highest peak currents and smallest peak separation in the CV of the aluminium anode suggested that this material was the most promising. Interestingly, carbon-based substrates appeared as an interesting alternative due to the high peak currents in CV, moderate overpotentials and dual role as anode and cathode. 3D substrates such as fiber-based carbon paper and aluminium mesh showed significantly smaller overpotentials and higher efficiencies for Al reaction suggesting that the use of 3D substrates in full batteries might result in enhanced power. This is corroborated by polarization testing of full Al-batteries.

Aluminium Electroplating on Steel from a Fused Bromide Electrolyte

Energy Technology Data Exchange (ETDEWEB)

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

2014-08-01

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

Assessment of ecological and human health risks of metals in urban road dust based on geochemical fractionation and potential bioavailability.

Science.gov (United States)

Jayarathne, Ayomi; Egodawatta, Prasanna; Ayoko, Godwin A; Goonetilleke, Ashantha

2018-09-01

Metals are one of the primary pollutants in the urban environment that pose adverse ecological and human health impacts. Therefore, the accurate quantification of the risk posed by metals is essential for developing effective risk management strategies to safeguard the urban environment. This study assessed the ecological and human health risks of six metals, commonly present in road dust by improving the original risk indices based on their potential bioavailability characteristics. The bioavailability of metals was determined by considering their distribution between the different geochemical phases of exchangeable, reducible, oxidisable and residual. The results of the modified risk analysis indicated that the road dust poses a low ecological risk in most of the study sites. According to the present situation, the non-cancer risk of individual metals for both, children and adults followed the decreasing trend of Pb > Cu > Cr > Zn > Ni > Cd. This study also found that depending on the particle size ranges, the potential of multiple metals being able to cause non-cancer health risk was low at most study sites. In terms of cancer health risk, Cr present at most of the study sites was found to be within the cancer threshold limit, even though the Cr content and the bioavailable fractions were relatively low. Copyright © 2018 Elsevier B.V. All rights reserved.

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

Science.gov (United States)

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

2015-08-01

Nowadays, despite improvements in safety rules and inspections in the metal industry, foundry workers are not free from burn accidents. Injuries caused by molten metals include burns secondary to molten iron, aluminium, zinc, copper, brass, bronze, manganese, lead and steel. Molten aluminium is one of the most common causative agents of burns (60%); however, only a few publications exist concerning injuries from molten aluminium. The main mechanisms of lesion from molten aluminium include direct contact of the molten metal with the skin or through safety apparel, or when the metal splash burns through the pants and rolls downward along the leg. Herein, we report three cases of deep dermal burns after 'soaking' the foot in liquid aluminium and its evolutive features. This paper aims to show our experience in the management of burns due to molten aluminium. We describe the current management principles and the key features of injury prevention. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

Numerical microstructure prediction for an aluminium casting and its experimental validation

Directory of Open Access Journals (Sweden)

Unterreiter Guenter

2011-08-01

Full Text Available Virtual manufacturing based on through-process modelling becomes an evolving research area which aims at integrating diverse simulation tools to realize computer-aided design, analysis, prototyping and manufacturing. Numerical prediction of the as-cast microstructure is an initial and critical step in the whole through-process modelling chain for engineering components. A commercial software package with the capability of calculating important microstructure features for aluminium alloys is used to simulate a G-AlSi7MgCu0.5 laboratory casting. The simulated microstructure, namely grain size, secondary dendrite arm spacing and diverse phase fractions are verified experimentally. Correspondence and discrepancies are reported and discussed.

Corrosion of Metal-Matrix Composites with Aluminium Alloy Substrate

Directory of Open Access Journals (Sweden)

B. Bobic

2010-03-01

Full Text Available The corrosion behaviour of MMCs with aluminium alloy matrix was presented. The corrosion characteristics of boron-, graphite-, silicon carbide-, alumina- and mica- reinforced aluminium MMCs were reviewed. The reinforcing phase influence on MMCs corrosion rate as well as on various corrosion forms (galvanic, pitting, stress corrosion cracking, corrosion fatique, tribocorrosion was discussed. Some corrosion protection methods of aluminium based MMCs were described

Cold forming of aluminium - State of the art

DEFF Research Database (Denmark)

Bay, Niels

1997-01-01

The ongoing development of cold forging technology has been manifested lately by the increasing application of components in cold forged aluminium alloys. Applying precipitation hardening alloys components with great strength/weight ratio can be produced with a strength comparable...... to that of unalloyed steel. After description of the different types of alloys and their individual properties and applications, the special requirements for tool design by cold forging in aluminium is discussed. Finally, a large number of industrial examples on cold forged aluminium components are presented. (C) 1997...

Effect of pressurized steam on AA1050 aluminium

DEFF Research Database (Denmark)

Jariyaboon, Manthana; Møller, Per; Ambat, Rajan

2012-01-01

Purpose - The purpose of this paper is to understand the effect of pressurized steam on surface changes, structures of intermetallic particles and corrosion behavior of AA1050 aluminium. Design/methodology/approach - Industrially pure aluminium (AA1050, 99.5 per cent) surfaces were exposed...... reactivities was observed due to the formation of the compact oxide layer. Originality/value - This paper reveals a detailed investigation of how pressurized steam can affect the corrosion behaviour of AA1050 aluminium and the structure of Fe-containing intermetallic particles....

Characterization of aluminium alloys rapidly solidified

International Nuclear Information System (INIS)

Monteiro, W.A.

1988-01-01

This paper discussed the investigation of the microstructural and mechanical properties of the aluminium alloys (3003; 7050; Al-9% Mg) rapidly solidified by melt spinning process (cooling rate 10 4 - 10 6 K/s). The rapidly solidification process of the studied aluminium alloys brought a microcrystallinity, a minimum presence of coarse precipitation and, also, better mechanical properties of them comparing to the same alloys using ingot process. (author) [pt

Sinter aluminium as cladding material for fuel elements; Aluminium fritte comme materiau de gainage pour les elements combustibles

Energy Technology Data Exchange (ETDEWEB)

Mann, K E; Boudouresques, M B [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Otto Fuchs, Meinerzhagen, Westfalen (Germany)

1961-07-01

1. Survey of the production process of sinter aluminium. 2. Description of the forming processes (extrusion, forging and rolling), whereby the production of tubing for atom piles will be explained in detail. 3. Production of ribbed tubes and tubes with close tolerances of sizes. 4. The different SAP-qualities and their properties under special consideration of the properties at elevated temperatures and the creep properties. 5. Diffusion behaviour of SAP with Be, Mg, Al, U and UO{sub 2}. 6. Corrosion behaviour in CO{sub 2} atmosphere at high temperature and in water. 7. Weldability. 8. Effect of irradiation on the mechanical properties. 9. Superiority of SAP compared with normal wrought alloys of the same composition. (author) [French] 1. Apercu des processus de production de l'aluminium fritte. 2. Expose des operations de transformation (filageries, forgeage et laminage), avec explication detaillee de la fabrication de gaine pour reacteurs. 3. Fabrication de tubes canneles et de tubes avec de faibles tolerances. 4. Diverses proprietes de l'aluminium fritte SAP, notamment proprietes aux temperatures elevees et proprietes de fluage. 5. Diffusion de l'aluminium fritte SAP en presence de Be, Mg, Al, U et UO{sub 2}. 6. Resistance a la corrosion dans une atmosphere de CO{sub 2} a temperature elevee et dans l'eau. 7. Possibilites de soudage. 8. Effet de l'irradiation sur les proprietes mecaniques. 9. Superiorite de l'aluminium fritte SAP sur les alliages forges normaux de meme composition. (auteur)

Sr-Nd-Hf Isotopic Analysis of <10 mg Dust Samples: Implications for Ice Core Dust Source Fingerprinting

DEFF Research Database (Denmark)

Ujvari, Gabor; Wegner, Wencke; Klötzli, Urs

2018-01-01

Combined Sr‐Nd‐Hf isotopic data of two reference materials (AGV‐1/BCR2) and 50, 10, and 5 mg aliquots of carbonate‐free fine grain (isotopic...... compositions (ICs) demonstrate that robust isotopic ratios can be obtained from 5 to 10 mg size rock samples using the ion exchange/mass spectrometry techniques applied. While 87Sr/86Sr ratios of dust aluminosilicate fractions are affected by even small changes in pretreatments, Nd isotopic ratios are found...... to be insensitive to acid leaching, grain‐size or weathering effects. However, the Nd isotopic tracer is sometimes inconclusive in dust source fingerprinting (BEI and NUS both close to ɛNd(0) –10). Hafnium isotopic values (

Low temperature oxidation of niobium alloy with silicon-aluminium coating

International Nuclear Information System (INIS)

Lazarev, Eh.M.; Sapozhnikova, L.V.; Shabanova, M.E.; Pod'yachev, V.N.; Kornilova, Z.I.

1987-01-01

Using the gravimetry methods heat resistance of niobium-titanium-aluminium alloy in the air and at 700 deg C in the initial state and when it is protected by silicide-aluminium coatings (with variable content of aluminium) is investigated. Using X-ray diffraction and micro X-ray diffraction analyses, mechanisms of the alloy oxidation and the coating protective effect are studied. The role of aluminium in the formation of coatings is analyzed and according to bend tests the plasticity of the coatings is evaluated

Dust generation in powders: Effect of particle size distribution

Directory of Open Access Journals (Sweden)

Chakravarty Somik

2017-01-01

Full Text Available This study explores the relationship between the bulk and grain-scale properties of powders and dust generation. A vortex shaker dustiness tester was used to evaluate 8 calcium carbonate test powders with median particle sizes ranging from 2μm to 136μm. Respirable aerosols released from the powder samples were characterised by their particle number and mass concentrations. All the powder samples were found to release respirable fractions of dust particles which end up decreasing with time. The variation of powder dustiness as a function of the particle size distribution was analysed for the powders, which were classified into three groups based on the fraction of particles within the respirable range. The trends we observe might be due to the interplay of several mechanisms like de-agglomeration and attrition and their relative importance.

SEM-EDS Analyses of Small Craters in Stardust Aluminum Foils: Implications for the Wild-2 Dust Distribution

Science.gov (United States)

Borg, J.; Horz, F.; Bridges, J. C.; Burchell, M. J.; Djouadi, Z.; Floss, C.; Graham, G. A.; Green, S. F.; Heck, P. R.; Hoppe, P.;

The structure of high-quality aluminium cast iron

Directory of Open Access Journals (Sweden)

D. Kopyciński

2012-01-01

Full Text Available In this study presents the analyse of aluminium iron cast structure (as-cast condition which are used in high temperature. While producing the casts of aluminium iron major influence has been preserve the structure of technological process parameters. The addition to Fe-C-Al alloy V, Ti, Cr leads to the improvement of functional and mechanical cast qualities. In this study, a method was investigated to eliminate the presence of undesirable Al4C3 phases in a aluminium cast iron structure and thus improve the production process. V and Ti additions in aluminium cast iron allows to development of FeAl - VC or TiC alloys. In particular, V or Ti contents above 5 wt.% were found to totally eliminate the presence of Al4C3. In addition, preliminary work indicates that the alloy with the FeAl - VC or TiC structure reveals high oxidation resistance. The introduction of 5 wt.% chromium to aluminium cast iron strengthened Al4C3 precipitate. Thus, the resultant alloy can be considered an intermetallic FeAl matrix strengthened by VC and TiC or modified Al4C3 reinforcements.

Method of preparing an Al-Ti-B grain refiner for aluminium-comprising products, and a method of casting aluminium products

NARCIS (Netherlands)

Brinkman, H.J.; Duszczyk, J.; Katgerman, L.

1999-01-01

The invention relates to a method of preparing an Al-Ti-B grain refiner for cast aluminium-comprising products. According to the invention the preparation is realized by mixing powders selected from the group comprising aluminium, titanium, boron, and alloys and intermetallic compounds thereof,

Recovery of tritium from lithium-sintered aluminium product (SAP) and lithium-aluminium alloys

International Nuclear Information System (INIS)

Talbot, J.B.; Wiffen, F.W.

1979-01-01

The tritium release rates of irradiated samples of lithium-containing aluminium (Li-Al) and sintered aluminium product (Li-SAP) were investigated to evaluate the potential application of both materials in fusion reactors. The observed release rates followed the pattern expected for bulk diffusion of tritium in a solid. Therefore, diffusion coefficients for tritium in Li-SAP were determined over a temperature range of 383 and 500 0 C and tritium in Li-Al at 450 0 C. At 450 0 C, the diffusion coefficients of tritium in Li-SAP and Li-Al are 2.988 x 10 -10 cm 2 sec -1 and 1.462 x 10 -6 cm 2 sec -1 , respectively. (author)

Evaluating Ice Nucleating Particle Concentrations From Prognostic Dust Minerals in an Earth System Model

Science.gov (United States)

Perlwitz, J. P.; Knopf, D. A.; Fridlind, A. M.; Miller, R. L.; Pérez García-Pando, C.; DeMott, P. J.

2016-12-01

The effect of aerosol particles on the radiative properties of clouds, the so-called, indirect effect of aerosols, is recognized as one of the largest sources of uncertainty in climate prediction. The distribution of water vapor, precipitation, and ice cloud formation are influenced by the atmospheric ice formation, thereby modulating cloud albedo and thus climate. It is well known that different particle types possess different ice formation propensities with mineral dust being a superior ice nucleating particle (INP) compared to soot particles. Furthermore, some dust mineral types are more proficient INP than others, depending on temperature and relative humidity.In recent work, we have presented an improved dust aerosol module in the NASA GISS Earth System ModelE2 with prognostic mineral composition of the dust aerosols. Thus, there are regional variations in dust composition. We evaluated the predicted mineral fractions of dust aerosols by comparing them to measurements from a compilation of about 60 published literature references. Additionally, the capability of the model to reproduce the elemental composition of the simulated dusthas been tested at Izana Observatory at Tenerife, Canary Islands, which is located off-shore of Africa and where frequent dust events are observed. We have been able to show that the new approach delivers a robust improvement of the predicted mineral fractions and elemental composition of dust.In the current study, we use three-dimensional dust mineral fields and thermodynamic conditions, which are simulated using GISS ModelE, to calculate offline the INP concentrations derived using different ice nucleation parameterizations that are currently discussed. We evaluate the calculated INP concentrations from the different parameterizations by comparing them to INP concentrations from field measurements.

Thermal formation of corundum from aluminium hydroxides ...

Indian Academy of Sciences (India)

Aluminium hydroxides have been precipitated from various aluminium salts and the differences in their thermal behaviour have been investigated. Pseudoboehmite derived from the nitrate, sulfate and chloride all form -Al2O3 at ∼ 400°C but the formation of -Al2O3 at 1200°C occurs more readily in the material derived ...

Thermal formation of corundum from aluminium hydroxides ...

Indian Academy of Sciences (India)

Abstract. Aluminium hydroxides have been precipitated from various aluminium salts and the differences in their thermal behaviour have been investigated. Pseudoboehmite derived from the nitrate, sulfate and chloride all form γ-Al2O3 at ~ 400°C but the formation of α-Al2O3 at 1200°C occurs more readily in the material ...

Influence of Alkali Treatment on the Surface Area of Aluminium Dross

Directory of Open Access Journals (Sweden)

N. S. Ahmad Zauzi

2016-01-01

Full Text Available Aluminium dross is an industrial waste from aluminium refining industry and classified as toxic substances. However, the disposal of dross as a waste is a burden to aluminium manufacturer industries due to its negative effects to the ecosystem, surface, and ground water. Therefore the purpose of this study is to evaluate the influence of sodium hydroxide (NaOH on the surface area and pore size of aluminium dross. There were 3 stages in the treatment activities, which were leaching, precipitation, and calcination process. The optimum result from this study was the surface area of aluminium dross increases from 10.1 m2/g up to 80.0 m2/g at 40°C, 1% NaOH, and 15-minute reaction time. Thus, aluminium dross has a potential to be converted into other useful material such as catalyst and absorbent. The benefit of this research is that the hazardous industrial waste can be turned into wealth to be used in other applications such as in catalytic activities and absorber in waste water treatment. Further investigation on the physicochemical of aluminium dross with different acid or alkali should be conducted to get deeper understanding on the aluminium dross as a catalyst-type material.

Elastic and plastic properties of iron-aluminium alloys. Special problems raised by the brittleness of alloys of high aluminium content; Proprietes elastiques et plastiques des alliages fer-aluminium. Problemes particuliers poses par la fragilite des alliages a forte teneur en aluminium

Energy Technology Data Exchange (ETDEWEB)

Mouturat, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1966-06-01

The present study embodies the results obtained with iron-aluminium alloys whose composition runs from 0 to nearly 50 atoms per cent aluminium. Conditions of elaboration and transformation have been studied successively, as well as the Young's modulus and the flow stress; the last chapter embodies, a study of the Portevin-le-Chatelier effect in alloys of 40 atoms per cent of aluminium. I) The principal difficulty to clear up consisted in the intergranular brittleness of ordered alloys; this brittleness has been considerably reduced with appropriate conditions of elaboration and transformation. II) The studies upon the Young's modulus are in connection with iron-aluminium alloys; transformation temperatures are well shown up. The formation of covalent bonds on and after 25 atoms per cent show the highest values of the modulus. III) The analysis of variations of the flow stress according to the temperature show some connection with ordered structures, the existence of antiphase domains and the existence of sur-structure dislocations. IV) In the ordered Fe Al domain the kinetics of the Portevin-le-Chatelier effect could be explained by a mechanism of diffusion of vacancies. The role they play has been specified by the influence they exert upon the dislocations; this has led us to the inhomogeneous Rudman order; this inhomogeneous order could explain the shape of the traction curves. (author) [French] Cette etude comporte les resultats obtenus avec des alliages fer-aluminium dont la composition s'etend de 0 a pres de 50 atomes pour cent d'aluminium. Nous avons etudie successivement les conditions d'elaboration et de transformation, le module elastique et la limite elastique; un dernier chapitre est consacre a l'etude du phenomene Portevin-le-Chatelier dans les alliages a 40 atomes pour cent d'aluminium. I) La principale difficulte a resoudre residait dans la fragilite intergranulaire des alliages ordonnes; celle-ci a ete considerablement reduite par des conditions

41 CFR 50-204.50 - Gases, vapors, fumes, dusts, and mists.

Science.gov (United States)

2010-07-01

... Soapstone 20 Talc 20 Portland cement 50 Graphite (natural) 15 Coat dust (respirable fraction less than 5% Si...-selector with the following characteristics: Aerodynamic diameter (unit density sphere) Percent passing...

The binding, transport and fate of aluminium in biological cells.

Science.gov (United States)

Exley, Christopher; Mold, Matthew J

2015-04-01

Aluminium is the most abundant metal in the Earth's crust and yet, paradoxically, it has no known biological function. Aluminium is biochemically reactive, it is simply that it is not required for any essential process in extant biota. There is evidence neither of element-specific nor evolutionarily conserved aluminium biochemistry. This means that there are no ligands or chaperones which are specific to its transport, there are no transporters or channels to selectively facilitate its passage across membranes, there are no intracellular storage proteins to aid its cellular homeostasis and there are no pathways which evolved to enable the metabolism and excretion of aluminium. Of course, aluminium is found in every compartment of every cell of every organism, from virus through to Man. Herein we have investigated each of the 'silent' pathways and metabolic events which together constitute a form of aluminium homeostasis in biota, identifying and evaluating as far as is possible what is known and, equally importantly, what is unknown about its uptake, transport, storage and excretion. Copyright © 2014 Elsevier GmbH. All rights reserved.

Speciation of aluminium, arsenic and molybdenum in excessively limed lakes

International Nuclear Information System (INIS)

Sjoestedt, Carin; Waellstedt, Teresia; Gustafsson, Jon Petter; Borg, Hans

2009-01-01

The possible existence of the potentially toxic oxyanions of Al (Al(OH) 4 - ), As (HAsO 4 2- ), and Mo (MoO 4 2- ) was examined in excessively limed lakes. In-situ dialysis (MWCO 1 kDa) was performed in the surface and bottom waters of two excessively limed lakes (pH 7.1-7.7) and one acidic lake (pH ∼ 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.

Optical and microphysical properties of natural mineral dust and anthropogenic soil dust near dust source regions over northwestern China

Directory of Open Access Journals (Sweden)

X. Wang

2018-02-01

Full Text Available Mineral dust aerosols (MDs not only influence the climate by scattering and absorbing solar radiation but also modify cloud properties and change the ecosystem. From 3 April to 16 May 2014, a ground-based mobile laboratory was deployed to measure the optical and microphysical properties of MDs near dust source regions in Wuwei, Zhangye, and Dunhuang (in chronological order along the Hexi Corridor over northwestern China. Throughout this dust campaign, the hourly averaged (±standard deviation aerosol scattering coefficients (σsp, 550 nm of the particulates with aerodynamic diameters less than 2.5 µm (PM2.5 at these three sites were sequentially 101.5 ± 36.8, 182.2 ± 433.1, and 54.0 ± 32.0 Mm−1. Correspondingly, the absorption coefficients (σap, 637 nm were 9.7 ± 6.1, 6.0 ± 4.6, and 2.3 ± 0.9 Mm−1; single-scattering albedos (ω, 637 nm were 0.902 ± 0.025, 0.931 ± 0.037, and 0.949 ± 0.020; and scattering Ångström exponents (Åsp, 450–700 nm of PM2.5 were 1.28 ± 0.27, 0.77 ± 0.51, and 0.52 ± 0.31. During a severe dust storm in Zhangye (i.e., from 23 to 25 April, the highest values of σsp2.5 ( ∼  5074 Mm−1, backscattering coefficient (σbsp2.5,  ∼  522 Mm−1, and ω637 ( ∼  0.993 and the lowest values of backscattering fraction (b2.5,  ∼  0.101 at 550 nm and Åsp2.5 ( ∼  −0.046 at 450–700 nm, with peak values of aerosol number size distribution (appearing at the particle diameter range of 1–3 µm, exhibited that the atmospheric aerosols were dominated by coarse-mode dust aerosols. It is hypothesized that the relatively higher values of mass scattering efficiency during floating dust episodes in Wuwei and Zhangye are attributed to the anthropogenic soil dust produced by agricultural cultivations.

Wear and chemistry of zirconium-silicate, aluminium-silicate and zirconium-aluminium-silicate glasses in alkaline medium

International Nuclear Information System (INIS)

Rouse, C.G.; Lemos Guenaga, C.M. de

1984-01-01

A study of the chemical durability, in alkaline solutions, of zirconium silicate, aluminium silicate, zirconium/aluminium silicate glasses as a function of glass composition is carried out. The glasses were tested using standard DIN-52322 method, where the glass samples are prepared in small polished pieces and attacked for 3 hours in a 800 ml solution of 1N (NaOH + NA 2 CO 3 ) at 97 0 C. The results show that the presence of ZrO 2 in the glass composition increases its chemical durability to alkaline attack. Glasses of the aluminium/zirconium silicate series were melted with and without TiO 2 . It was shown experimentally that for this series of glasses, the presence of both TiO 2 and ZrO 2 gave better chemical durability results. However, the best overall results were obtained from the simpler zirconium silicate glasses, where it was possible to make glasses with higher values of ZrO 2 . (Author) [pt

Aluminium effect on the physical properties of titanium

International Nuclear Information System (INIS)

Nazimov, O.P.; Il'in, A.A.; Zvonova, L.N.

1977-01-01

The effect of aluminium on the physical properties of titanium was investigated. Within the framework of the configuration model of matter it is shown that a change in physical properties with an aluminium content of up to 7.5 wt.% in alloys depends on the phase composition and electron structure. In interacting with titanium, aluminium exhibits acceptor properties, causing d→s electron transitions. The electrons which have shifted to the s-state are partly collectivized and partly localized into quasistable sp 3 configurations, with the resulting increase of the interatomic forces. An intensification of d→s transitions in alloying of titanium with aluminium stabilizes the α-phase. Predominance of d 1 configurations in the intermediate spectrum in the region of the α-solution increases the ratio of the axes of the HCP lattice and determines the electron type of conduction of alloys of the Ti-Al system

Aluminium and Aroma Compound Concentration in Beer During Storage at Different Temperatures

Directory of Open Access Journals (Sweden)

Marija Soldo Gjeldum

2006-01-01

Full Text Available Problem of aluminium in beer has been elaborated in several papers over the last decade. However, the effect of aluminium on organoleptic properties of beer has been observed in few papers where it has been stated that aluminium gives beer a »metallic« and bitter flavour without any observations on particular aroma compound changes. Also, the number of reports on precise changes of aroma components throughout different storage conditions is surprisingly scarce. In order to investigate the changes of aluminium concentration along with aroma compound changes, graphite furnace-atomic absorption spectrophotometry (GF-AAS with Zeeman background correction and gas chromatography with static headspace sampler (GC-HSS were used in this work. Analyses were conducted periodically throughout seven months of storage on three different brands of beer from name breweries. Samples were taken before and after filling in aluminium cans. One part of samples was stored in a refrigerator (4 °C and the other in a thermostatic chamber (22 °C. The effects of beer brand and storage conditions on aluminium concentration and level of aroma compounds were measured. To prove the effect of aluminium concentration on the changes of aroma compounds, the adequate level of aluminium sulphate was added to bottled beer samples stored at 28 °C. Although different beer types showed significantly different aluminium concentration, it could be the result of other factors (different batches of identical beer type showed significantly different aluminium concentration as well. Samples that were stored in the refrigerator were protected from aluminium migration from the can to the beer and showed increased aroma stability. Level of aroma constituents of analyzed beer brands was significantly different. Elevated aluminium concentration did not have any noticeable effect on the level of aroma compounds in beer samples stored at 28 °C.

Experimental Realisation of Elusive Multiple-bonded Aluminium Compounds: A New Horizon in the Aluminium Chemistry.

Science.gov (United States)

Inoue, Shigeyoshi; Bag, Prasenjit; Weetman, Catherine

2018-05-23

Synthesis and isolation of stable main group compounds featuring multiple bonds has been of keen interest for the last several decades. Multiply bonded complexes were obtained using sterically demanding substituents that provide kinetic and thermodynamic stability. Many of these compounds have unusual structural and electronic properties that challenges the classical concept of covalent multiple bonding. In contrast, analogous aluminium compounds are scarce in spite of its high natural abundance. The parent dialumene (Al2H2) has been calculated to be extremely weak, thus making Al multiple bonds a challenging synthetic target. This review provides an overview of these recent advances in the cutting edge synthetic approaches used to obtain aluminium homo- and heterodiatomic multiply bonded complexes. Additionally, the reactivity of these novel compounds towards various small molecules and reagents will be discussed herein. This review provides an overview on the current progress in aluminium multiple bond chemistry and the careful ligand design required to stabilise these reactive species. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sintered aluminium powders

International Nuclear Information System (INIS)

Stepanova, M.G.; Matveev, B.I.

1974-01-01

The mechanical and physical properties of aluminium powder alloys and the various methods employed to produce them are considered. Data are given on the hardening of the alloys SAP and SPAK-4, as well as the powder-alloy system Al-Cr-Zr. (L.M.)

Silane based coating of aluminium mold

DEFF Research Database (Denmark)

2013-01-01

having at least one closed cavity is provided, at least one surface of the at least one cavity being an aluminium surface coated with a silane based coating layer. The silane based anti-stiction coating improves the anti-stiction properties of the mold which may allow for molding and demolding...... of structures which would otherwise be difficult to mold. The resistance of the coated aluminium mold is significantly improved by applying a silane-based coating layer....

Chemical profiling of PM10 from urban road dust.

Science.gov (United States)

Alves, C A; Evtyugina, M; Vicente, A M P; Vicente, E D; Nunes, T V; Silva, P M A; Duarte, M A C; Pio, C A; Amato, F; Querol, X

2018-09-01

Road dust resuspension is one of the main sources of particulate matter with impacts on air quality, health and climate. With the aim of characterising the thoracic fraction, a portable resuspension chamber was used to collect road dust from five main roads in Oporto and an urban tunnel in Braga, north of Portugal. The PM 10 samples were analysed for: i) carbonates by acidification and quantification of the evolved CO 2 , ii) carbonaceous content (OC and EC) by a thermo-optical technique, iii) elemental composition by ICP-MS and ICP-AES after acid digestion, and iv) organic speciation by GC-MS. Dust loadings of 0.48±0.39mgPM 10 m -2 were obtained for asphalt paved roads. A much higher mean value was achieved in a cobbled pavement (50mgPM 10 m -2 ). In general, carbonates were not detected in PM 10 . OC and EC accounted for PM 10 mass fractions up to 11% and 5%, respectively. Metal oxides accounted for 29±7.5% of the PM 10 mass from the asphalt paved roads and 73% in samples from the cobbled street. Crustal and anthropogenic elements, associated with tyre and brake wear, dominated the inorganic fraction. PM 10 comprised hundreds of organic constituents, including hopanoids, n-alkanes and other aliphatics, polycyclic aromatic hydrocarbons (PAH), alcohols, sterols, various types of acids, glycerol derivatives, lactones, sugars and derivatives, phenolic compounds and plasticizers. In samples from the cobbled street, these organic classes represented only 439μgg -1 PM 10 , while for other pavements mass fractions up to 65mgg -1 PM 10 were obtained. Except for the cobbled street, on average, about 40% of the analysed organic fraction was composed of plasticizers. Although the risk via inhalation of PAH was found to be insignificant, the PM 10 from some roads can contribute to an estimated excess of 332 to 2183 per million new cancer cases in adults exposed via ingestion and dermal contact. Copyright © 2018 Elsevier B.V. All rights reserved.

Aluminium (Al) fractionation and speciation: getting closer to describing the factors influencing Al(sup3+) in water impacted by acid mine drainage

CSIR Research Space (South Africa)

Chamier, J

2015-07-01

Full Text Available Acid mine drainage (AMD) severely impacts the water chemistry of a receiving resource, changing the occurrence, speciation and toxicity of metals such as Aluminium (Al). The toxicity of Al is determined by its speciation represented by the labile...

Aluminium hydroxide-induced granulomas in pigs

DEFF Research Database (Denmark)

Valtulini, S; Macchi, C; Ballanti, P

2005-01-01

The effect of intramuscular injection of 40 mg/2 ml aluminium hydroxide in the neck of pigs was examined in a number of ways. The investigation followed repeated slaughterhouse reports, according to which 64.8% of pigs from one particular farm were found at slaughter to have one or more nodules...... in the muscles of the neck (group slaughtered). The pigs had been injected with a vaccine containing 40 mg/2 ml dose of aluminium hydroxide as adjuvant. Research consisted of two phases: first, an epidemiological study was carried out, aimed at determining the risk factors for the granulomas. The results...... and adjuvant) to pigs inoculated twice with apyrogenic bi-distilled water (group water) and to pigs inoculated once with the adjuvant and once with apyrogenic bi-distilled water (group adjuvant/water). Both studies agreed in their conclusions, which indicate that the high amount of aluminium hydroxide...

Finite size melting of spherical solid-liquid aluminium interfaces

DEFF Research Database (Denmark)

Chang, J.; Johnson, Erik; Sakai, T.

2009-01-01

We have investigated the melting of nano-sized cone shaped aluminium needles coated with amorphous carbon using transmission electron microscopy. The interface between solid and liquid aluminium was found to have spherical topology. For needles with fixed apex angle, the depressed melting tempera...... to the conclusion that the depressed melting temperature is not controlled solely by the inverse radius 1/R. Instead, we found a direct relation between the depressed melting temperature and the ratio between the solid-liquid interface area and the molten volume.......We have investigated the melting of nano-sized cone shaped aluminium needles coated with amorphous carbon using transmission electron microscopy. The interface between solid and liquid aluminium was found to have spherical topology. For needles with fixed apex angle, the depressed melting...

Structural perturbation of diphtheria toxoid upon adsorption to aluminium hydroxide adjuvant

NARCIS (Netherlands)

Regnier, M.; Metz, B.; Tilstra, W.; Hendriksen, C.; Jiskoot, W.; Norde, W.; Kersten, G.

2012-01-01

Aluminium-containing adjuvants are often used to enhance the potency of vaccines. In the present work we studied whether adsorption of diphtheria toxoid to colloidal aluminium hydroxide induces conformational changes of the antigen. Diphtheria toxoid has a high affinity for the aluminium hydroxide

Disruption of an Alumina Layer During Sintering of Aluminium in Nitrogen

Directory of Open Access Journals (Sweden)

Pieczonka T.

2017-06-01

Full Text Available Aluminium oxide layer on aluminium particles cannot be avoided. However, to make the metal-metal contacts possible, this sintering barrier has to be overcome in some way, necessarily to form sintering necks and their development. It is postulated that the disruption of alumina layer under sintering conditions may originate physically and chemically. Additionally, to sinter successfully non alloyed aluminium powder in nitrogen, the operation of both types mechanism is required. It is to be noted that metallic aluminium surface has to be available to initiate reactions between aluminium and the sintering atmosphere, i.e. mechanical disruption of alumina film precedes the chemical reactions, and only then chemically induced mechanisms may develop. Dilatometry, gravimetric and differential thermal analyses, and microstructure investigations were used to study the sintering response of aluminium at 620°C in nitrogen, which is the only sintering atmosphere producing shrinkage.

Influence of Matrix Composition on the Bioaccessibility of Copper, Zinc and Nickel in Urban Residential Dust and Soil

International Nuclear Information System (INIS)

Rasmussen, P.; Beauchemin, S.; Nugent, M.; Dugandzic, R.; Lanouette, M.; Chenier, M.

2008-01-01

This study examines factors affecting oral bioaccessibility of metals in household dust, in particular metal speciation, organic carbon content, and particle size, with the goal of addressing risk assessment information requirements. Investigation of copper (Cu) and zinc (Zn) speciation in two size fractions of dust (< 36 μ m and 80-150 μ m) using synchrotron X-ray absorption spectroscopy (XAS) indicates that the two metals are bound to different components of the dust: Cu is predominately associated with the organic phase of the dust, while Zn is predominately associated with the mineral fraction. Total and bioaccessible Cu, nickel (Ni), and Zn were determined (on dry weight basis) in the < 150 μ m size fraction of a set of archived indoor dust samples (n = 63) and corresponding garden soil samples (n = 66) from the City of Ottawa, Canada. The median bioaccessible Cu content is 66 μ g g-1 in dust compared to 5 μ g g-1 in soil; the median bioaccessible Ni content is 16 μ g g-1 in dust compared to 2 μ g g-1 in soil; and the median bioaccessible Zn content is 410 μ g g-1 in dust compared to 18 μ g g-1 in soil. For the same data set, the median total Cu content is 152 μ g g-1 in dust compared to 17 μ g g-1 in soil; the median total Ni content is 41 μ g g-1 in dust compared to 13 μ g g-1 in soil; and the median total Zn content is 626 μ g g-1 in dust compared to 84 μ g g-1 in soil. Organic carbon is elevated in indoor dust (median 28%) compared to soil (median 5%), and is a key factor controlling metal partitioning and therefore bioaccessibility. The results show that house dust and soil have distinct geochemical signatures and should not be treated as identical media in exposure and risk assessments. Separate measurements of the indoor and outdoor environment are essential to improve the accuracy of residential risk assessments.

Recycled Aluminium Cans/Eggshell Composites: Evaluation of Mechanical and Wear Resistance Properties

Directory of Open Access Journals (Sweden)

J.O. Agunsoye

2015-03-01

Full Text Available Aluminium based metal matrix composites have been produced from recycled aluminium cans and 150µm sized eggshell particles using a stir cast process. The mechanical properties of the control and aluminium can/eggshell composites produced have been investigated. The microstructures of the aluminium can/eggshell composites were examined with the aids of Scanning Electron Microscope (SEM after the sample surfaces have been carefully prepared and etched with aqueous solution of 0.5 cm3 nitric acid. Micrographs revealed that there was a homogenous distribution of eggshell particles within the aluminium can matrix. An indication of effective stirring action during the melting process. The wear resistance was also investigated under different applied loads (6 to 14 N on an abrasive surface emery paper of grade 220. The results revealed an increase in Young’s modulus of elasticity and yield stress from 1,206.45 and 50.23 Mpa respectively of the cast aluminium can with 0 % eggshell particle to the maximum of 3,258.87and 73.2 MPa of aluminium can/12 % eggshell composites. The hardness values increased from 66.23 to 75.13 VN. There was a gradual increase in wear rate of the tested samples as the applied load increased. However, the wear resistance of the aluminium can/6 % eggshell and aluminium can/12 % eggshell composites increased significantly. Hence, recycling of aluminium cans and eggshells can be harnessed into development of useful engineering metal matrix composite materials.

Spectral- and size-resolved mass absorption efficiency of mineral dust aerosols in the shortwave spectrum: a simulation chamber study

Science.gov (United States)

Caponi, Lorenzo; Formenti, Paola; Massabó, Dario; Di Biagio, Claudia; Cazaunau, Mathieu; Pangui, Edouard; Chevaillier, Servanne; Landrot, Gautier; Andreae, Meinrat O.; Kandler, Konrad; Piketh, Stuart; Saeed, Thuraya; Seibert, Dave; Williams, Earle; Balkanski, Yves; Prati, Paolo; Doussin, Jean-François

2017-06-01

This paper presents new laboratory measurements of the mass absorption efficiency (MAE) between 375 and 850 nm for 12 individual samples of mineral dust from different source areas worldwide and in two size classes: PM10. 6 (mass fraction of particles of aerodynamic diameter lower than 10.6 µm) and PM2. 5 (mass fraction of particles of aerodynamic diameter lower than 2.5 µm). The experiments were performed in the CESAM simulation chamber using mineral dust generated from natural parent soils and included optical and gravimetric analyses. The results show that the MAE values are lower for the PM10. 6 mass fraction (range 37-135 × 10-3 m2 g-1 at 375 nm) than for the PM2. 5 (range 95-711 × 10-3 m2 g-1 at 375 nm) and decrease with increasing wavelength as λ-AAE, where the Ångström absorption exponent (AAE) averages between 3.3 and 3.5, regardless of size. The size independence of AAE suggests that, for a given size distribution, the dust composition did not vary with size for this set of samples. Because of its high atmospheric concentration, light absorption by mineral dust can be competitive with black and brown carbon even during atmospheric transport over heavy polluted regions, when dust concentrations are significantly lower than at emission. The AAE values of mineral dust are higher than for black carbon (˜ 1) but in the same range as light-absorbing organic (brown) carbon. As a result, depending on the environment, there can be some ambiguity in apportioning the aerosol absorption optical depth (AAOD) based on spectral dependence, which is relevant to the development of remote sensing of light-absorbing aerosols and their assimilation in climate models. We suggest that the sample-to-sample variability in our dataset of MAE values is related to regional differences in the mineralogical composition of the parent soils. Particularly in the PM2. 5 fraction, we found a strong linear correlation between the dust light-absorption properties and elemental

Surface roughness when diamond turning RSA 905 optical aluminium

Science.gov (United States)

Otieno, T.; Abou-El-Hossein, K.; Hsu, W. Y.; Cheng, Y. C.; Mkoko, Z.

2015-08-01

Ultra-high precision machining is used intensively in the photonics industry for the production of various optical components. Aluminium alloys have proven to be advantageous and are most commonly used over other materials to make various optical components. Recently, the increasing demand from optical systems for optical aluminium with consistent material properties has led to the development of newly modified grades of aluminium alloys produced by rapid solidification in the foundry process. These new aluminium grades are characterised by their finer microstructures and refined mechanical and physical properties. However the machining database of these new optical aluminium grades is limited and more research is still required to investigate their machinability performance when they are diamond turned in ultrahigh precision manufacturing environment. This work investigates the machinability of rapidly solidified aluminium RSA 905 by varying a number of diamond-turning cutting parameters and measuring the surface roughness over a cutting distance of 4 km. The machining parameters varied in this study were the cutting speed, feed rate and depth of cut. The results showed a common trend of decrease in surface roughness with increasing cutting distance. The lowest surface roughness Ra result obtained after 4 km in this study was 3.2 nm. This roughness values was achieved using a cutting speed of 1750 rpm, feed rate of 5 mm/min and depth of cut equal to 25 μm.

Component, Disperse and Morphological Composition of Ambient Air Dust Contamination in the Zones of Mining-Processing Enterprises

Science.gov (United States)

Zagorodnov, S. Y.; Kokoulina, A. A.; Klein, S. V.

2017-07-01

The article presents the results of complex studies of dust emissions of the mining and processing complex. The main technological processes and the sources operation that produce intense dust emissions are determined. It has been proved that dust emissions of the investigated enterprise contain fine dust dangerous for human health. The results of the studies allowed us to detect precisely the dispersed composition of dust emissions, with the separation of PM10 and PM2.5 fractions, the chemical composition of the dust, and the shape of the particles. Thus, operating with obtained data on dispersed composition of the dust emissions and the specified sedimentation coefficient, we were able to calculate the dispersion of all solid particles and separately the PM10 and PM2.5 at the location of the enterprise. The dust exposure of the population at the targeted zones has been also determined. The obtained concentration values were used for assess health risk level to population living at the border of sanitary protection zone of the enterprise. Due to the obtained results, the enterprise was provided with recommendations on the inclusion of fine particles PM 10 and PM 2.5 in the production control program. In the case of increasing its production capacity was recommended to introduce the environmental measures for the reduction of emission of the finely dispersed fractions PM10 and PM 2.5.

MUTAGENIC AND CYTOTOXIC FACTORS IN PM10 AND PM2.5 FRACTIONS IN ATMOSPHERE IN SOSNOWIEC

Directory of Open Access Journals (Sweden)

Agnieszka Kozłowska

2011-12-01

Full Text Available Air dust pollution enters human body via respiratory system. Its cytotoxic effect is surveyed using cell lines of mononuclear or pulmonary epithelial cell origins. Mutagenic properties are assessed using short-term assay on Salmonella typhimurium bacterial strains. Mutagenic and cytotoxic properties of air dust pollution – fractions PM10 and PM2.5, which were collected in autumn and in winter, were assessed using Ames test with Salmonella typhimurium strains and MTT cytoxicity assay on mononuclear cell line RAW 264.7, respectively. Samples of dust were collected on glass fiber filters by (Harvard impactor with air flow ca. 9 l/min, splitting samples to the fraction PM10 and PM2.5. Extraction of pollution was carried out using dichlorometane. Extracted samples were dissolved in dimethylsulfoxide (DMSO before analyses. The highest value of mutagenicity ratio (MR was observed in YG1041 strain with metabolic activation by S9 extract in the PM10 sample of dust collected in winter. The lowest one was observed in TA98 strain without activation in the PM2.5 sample of dust collected in autumn. Winter dust samples, both the fractions PM10 and PM2,5, were toxic for TA98 strain in both test conditions (5S9. MTT cytotoxicity assay using mononuclear cell line RAW 264.7 showed that fractions PM10 and PM2.5 collected in winter were of highest toxic properties. The viability of cells, which were treated with samples of 0,312 m3 air, were 1,7% and 1,6%, respectively, while for autumn samples for PM2,5 the viability was 63%.

In vivo monitoring of skeletal aluminium burden in patients with renal failure

International Nuclear Information System (INIS)

Ellis, K.J.; Kelleher, S.; Raciti, A.; Savory, J.; Wills, M.

1988-01-01

In vivo neutron activation analysis was used to examine the total body and partial body (hand) aluminium levels in patients with end-stage renal failure. Patients maintained on chronic hemodialysis had higher mean body burdens of aluminium than did those clinically managed without dialysis. Approximately 70% of the patients examined indicated elevated levels of body or skeletal aluminium. A significant correlation was observed between the in vivo aluminium/calcium ratio obtained for the hand measurement and the increase in serum aluminium levels following a disferroxamine infusion test. The direct in vivo monitoring of hand Al/Ca values in patients may provide an alternate choice to bone biopsy for the detection of aluminium intoxication. (author) 15 refs.; 5 figs.; 2 tabs

Dietary exposure to aluminium in the popular Chinese fried bread youtiao.

Science.gov (United States)

Li, Ge; Zhao, Xue; Wu, Shimin; Hua, Hongying; Wang, Qiang; Zhang, Zhiheng

2017-06-01

Youtiao is a typical, traditional and widely consumed fried food in China. Fermentation of youtiao involves the use of aluminium potassium sulphate (alum). There are health concerns related to the levels of aluminium in food; therefore, we aimed to determine the aluminium concentrations of youtiao from various locations, and to estimate the dietary exposure by different age groups in southern and northern China. The aluminium content of youtiao samples varied considerably (range = 4.46-852.69 mg kg -1 ). Both the mean and median aluminium contents of youtiao exceeded 100 mg kg -1 , which is the China National Standard (GB) 2760-2014 National Food Safety for Standards for food additives. However, the median and 97.5th percentile of weekly dietary exposure to aluminium from youtiao, estimated using Monte Carlo simulation, did not exceed the provisional tolerable weekly intake (PTWI) set by the joint FAO/WHO Expert Committee on Food Additives (JECFA) for children, adolescents, adults and seniors. The weekly dietary exposure to aluminium would exceed the PTWI if children, adolescents, adults and seniors consumed 134.47, 260.98, 327.10 or 320.41 g of youtiao per week, respectively.

A Standard Characterization Methodology for Respirable Coal Mine Dust Using SEM-EDX

Directory of Open Access Journals (Sweden)

Rachel Sellaro

2015-12-01

Full Text Available A key consideration for responsible development of mineral and energy resources is the well-being of workers. Respirable dust in mining environments represents a serious concern for occupational health. In particular, coal miners can be exposed to a variety of dust characteristics depending on their work activities, and some exposures may pose risk for lung diseases like CWP and silicosis. As underscored by common regulatory frameworks, respirable dust exposures are generally characterized on the basis of total mass concentration, and also the silica mass fraction. However, relatively little emphasis has been placed on other dust characteristics that may be important in terms of identifying health risks. Comprehensive particle-level analysis to estimate chemistry, size, and shape distributions of particles is possible. This paper describes a standard methodology for characterization of respirable coal mine dust using scanning electron microscopy (SEM with energy dispersive X-ray (EDX. Preliminary verification of the method is shown based several dust samples collected from an underground mine in Central Appalachia.

Silicon Alloying On Aluminium Based Alloy Surface

International Nuclear Information System (INIS)

Suryanto

2002-01-01

Silicon alloying on surface of aluminium based alloy was carried out using electron beam. This is performed in order to enhance tribological properties of the alloy. Silicon is considered most important alloying element in aluminium alloy, particularly for tribological components. Prior to silicon alloying. aluminium substrate were painted with binder and silicon powder and dried in a furnace. Silicon alloying were carried out in a vacuum chamber. The Silicon alloyed materials were assessed using some techniques. The results show that silicon alloying formed a composite metal-non metal system in which silicon particles are dispersed in the alloyed layer. Silicon content in the alloyed layer is about 40% while in other place is only 10.5 %. The hardness of layer changes significantly. The wear properties of the alloying alloys increase. Silicon surface alloying also reduced the coefficient of friction for sliding against a hardened steel counter face, which could otherwise be higher because of the strong adhesion of aluminium to steel. The hardness of the silicon surface alloyed material dropped when it underwent a heating cycle similar to the ion coating process. Hence, silicon alloying is not a suitable choice for use as an intermediate layer for duplex treatment

The use of fractionated fly ash of thermal power plants as binder for production of briquettes of coke breeze and dust

Science.gov (United States)

Temnikova, E. Yu; Bogomolov, A. R.; Lapin, A. A.

2017-11-01

In this paper, we propose to use the slag and ash material of thermal power plants (TPP) operating on pulverized coal fuel. The elemental and chemical composition of fly ash of five Kuzbass thermal power plants differs insignificantly from the composition of the mineral part of coking coal because coke production uses a charge, whose composition defines the main task: obtaining coke with the required parameters for production of iron and steel. These indicators are as follows: CRI reactivity and strength of the coke residue after reaction with CO2 - CSR. The chemical composition of fly ash of thermal power plants and microsilica with bulk density of 0.3-0.6 t/m3 generated at production of ferroalloys was compared. Fly ash and microsilica are the valuable raw material for production of mineral binder in manufacturing coke breeze briquettes (fraction of 2-10 mm) and dust (0-200 μm), generated in large quantities during coking (up to 40wt%). It is shown that this binder is necessary for production of smokeless briquettes with low reactivity, high strength and cost, demanded for production of cupola iron and melting the silicate materials, basaltic rocks in low-shaft furnaces. It is determined that microsilica contains up to 90% of silicon oxide, and fly ash contains up to 60% of silicon oxide and aluminum oxide of up to 20%. On average, the rest of fly ash composition consists of basic oxides. According to calculation by the VUKHIN formula, the basicity index of briquette changes significantly, when fly ash is introduced into briquette raw material component as a binder. The technology of coke briquette production on the basis of the non-magnetic fraction of TPP fly ash in the ratio from 3.5:1 to 4.5:1 (coke breeze : coke dust) with the addition of the binder component to 10% is proposed. The produced briquettes meet the requirements by CRI and require further study on CSR requirements.

Dust Creation in CNC Drilling of Wood Composites

Directory of Open Access Journals (Sweden)

Tomasz Rogoziński

2015-04-01

Full Text Available This paper presents the particle-size distribution of dust created by the drilling of selected wood composites, which was carried out using a CNC machine. The particle-size distribution was studied through two methods. Two analyses were performed: the sieve analysis of samples from the whole mass of collected dust and the laser diffraction analysis of the finest fraction isolated by sieving. The results presented general information about the particle-size distribution of the dust, as well as detailed information on the content of the finest particles. This information revealed that the particles might pose a potential risk to the health of workers employed in the woodworking industry. This potential risk is due to the possibility of their dispersion in the atmosphere surrounding the workplace and their size, which allows them to be respirable. The relationship between the fineness of the dust and the type of wood composite was also tested. Most ultrafine particles are formed during the drilling of fibreboards and are especially produced in traditional wet technology.

Dietary exposure to aluminium of urban residents from cities in South China.

Science.gov (United States)

Jiang, Qi; Wang, Jing; Li, Min; Liang, Xuxia; Dai, Guangwei; Hu, Zhikun; Wen, Jian; Huang, Qiong; Zhang, Yonghui

2013-01-01

A dietary survey was conducted over three consecutive days by using 24-hour dietary recall in the Pearl River Delta of South China to investigate the dietary consumption status. A total of 1702 food samples, 22 food groups, were collected, and aluminium concentrations of foods were determined by using ICP-MS. Weekly dietary exposure to aluminium of the average urban residents of South China was estimated to be 1.5 mg kg⁻¹ body weight, which amounted to 76% of the provisional tolerable weekly intake. Wheat-made products (53.5%) contributed most to the dietary exposure, followed by vegetables (12.2%). The high-level consumers' weekly exposure to aluminium was 11.1 mg kg⁻¹ body weight, which amounted to 407% of the provisional tolerable weekly intake. The results indicated that the general urban residents in South China might be safe from aluminium exposure, but the high-level consumers might be at some risk of aluminium exposure. The foods contributing to aluminium exposure were processed food with aluminium-containing food additives. It is necessary to take effective measures to control the overuse of aluminium-containing food additives.

Usage of neural network to predict aluminium oxide layer thickness.

Science.gov (United States)

Michal, Peter; Vagaská, Alena; Gombár, Miroslav; Kmec, Ján; Spišák, Emil; Kučerka, Daniel

2015-01-01

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

Usage of Neural Network to Predict Aluminium Oxide Layer Thickness

Directory of Open Access Journals (Sweden)

Peter Michal

2015-01-01

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

Elastic and plastic properties of iron-aluminium alloys. Special problems raised by the brittleness of alloys of high aluminium content; Proprietes elastiques et plastiques des alliages fer-aluminium. Problemes particuliers poses par la fragilite des alliages a forte teneur en aluminium

Energy Technology Data Exchange (ETDEWEB)

Mouturat, P. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1966-06-01

The present study embodies the results obtained with iron-aluminium alloys whose composition runs from 0 to nearly 50 atoms per cent aluminium. Conditions of elaboration and transformation have been studied successively, as well as the Young's modulus and the flow stress; the last chapter embodies, a study of the Portevin-le-Chatelier effect in alloys of 40 atoms per cent of aluminium. I) The principal difficulty to clear up consisted in the intergranular brittleness of ordered alloys; this brittleness has been considerably reduced with appropriate conditions of elaboration and transformation. II) The studies upon the Young's modulus are in connection with iron-aluminium alloys; transformation temperatures are well shown up. The formation of covalent bonds on and after 25 atoms per cent show the highest values of the modulus. III) The analysis of variations of the flow stress according to the temperature show some connection with ordered structures, the existence of antiphase domains and the existence of sur-structure dislocations. IV) In the ordered Fe Al domain the kinetics of the Portevin-le-Chatelier effect could be explained by a mechanism of diffusion of vacancies. The role they play has been specified by the influence they exert upon the dislocations; this has led us to the inhomogeneous Rudman order; this inhomogeneous order could explain the shape of the traction curves. (author) [French] Cette etude comporte les resultats obtenus avec des alliages fer-aluminium dont la composition s'etend de 0 a pres de 50 atomes pour cent d'aluminium. Nous avons etudie successivement les conditions d'elaboration et de transformation, le module elastique et la limite elastique; un dernier chapitre est consacre a l'etude du phenomene Portevin-le-Chatelier dans les alliages a 40 atomes pour cent d'aluminium. I) La principale difficulte a resoudre residait dans la fragilite intergranulaire des alliages ordonnes; celle-ci a ete

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

Science.gov (United States)

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

2013-10-01

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 μg/L. Method blanks were used to estimate background levels of contamination of 14.80 μg/L. The mean concentration of aluminium across all tissues was 0.39 μg 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

Paleo-dust insights onto dust-climate interactions

Science.gov (United States)

Albani, S.; Mahowald, N. M.

2017-12-01

Mineral dust emissions are affected by changing climate conditions, and in turn dust impacts the atmospheric radiation budget, clouds and biogeochemical cycles. Climate and public health dust-related issues call for attention on the fate of the dust cycle in the future, and the representation of the dust cycle is now part of the strategy of the Paleoclimate Modelling Intercomparison Project phase 4 and the Coupled Model Intercomparison Project phase 6 (PMIP4-CMIP6). Since mineral aerosols are one of the most important natural aerosols, understanding past dust responses to climate in the paleoclimate will allow us to better understand mineral aerosol feedbacks with climate and biogeochemistry in the Anthropocene. Modern observations and paleoclimate records offer the possibility of multiple, complementary views on the global dust cycle, and allow to validate and/or constrain the numerical representation of dust in climate and Earth system models. We present our results from a set of simulations with the Community Earth System Model for different climate states, including present and past climates such as the pre-industrial, the mid-Holocene and the Last Glacial Maximum. A set of simulations including a prognostic dust cycle was thoroughly compared with a wide set of present day observations from different platforms and regions, in order to realistically constrain the magnitude of dust load, surface concentration, deposition, optical properties, and particle size distributions. The magnitude of emissions for past climate regimes was constrained based on compilations of paleodust mass accumulation rates and size distributions, as well as based on information on dust provenance. The comparison with a parallel set of simulations without dust allows estimating the impacts of dust on surface climate. We analyze impacts of dust on the mean and variability of surface temperature and precipitation in each climate state, as well as the impacts that changing dust emissions had

Laboratory dust generation and size-dependent characterization of metal and metalloid-contaminated mine tailings deposits

Energy Technology Data Exchange (ETDEWEB)

Gonzales, Patricia; Felix, Omar [Department of Chemical and Environmental Engineering, University of Arizona, 1133 E. James E. Rogers Way, Tucson, AZ 85721 (United States); Alexander, Caitlin; Lutz, Eric [Division of Community, Environment, and Policy, Mel and Enid Zuckerman College of Public Health, University of Arizona, 1656 E. Mabel St., Tucson, AZ 85724 (United States); Ela, Wendell [Department of Chemical and Environmental Engineering, University of Arizona, 1133 E. James E. Rogers Way, Tucson, AZ 85721 (United States); Eduardo Sáez, A., E-mail: esaez@arizona.edu [Department of Chemical and Environmental Engineering, University of Arizona, 1133 E. James E. Rogers Way, Tucson, AZ 85721 (United States)

2014-09-15

Highlights: • A laboratory dust fractionator was developed for the production of respirable dust. • The size-dependent distribution of arsenic and lead in mine tailings dust is reported. • Metal and metalloid contaminants are enriched in particles smaller than 10 μm. • Lead isotope signatures show spread of mine tailings particles onto surrounding soils. - Abstract: The particle size distribution of mine tailings material has a major impact on the atmospheric transport of metal and metalloid contaminants by dust. Implications to human health should be assessed through a holistic size-resolved characterization involving multidisciplinary research, which requires large uniform samples of dust that are difficult to collect using conventional atmospheric sampling instruments. To address this limitation, we designed a laboratory dust generation and fractionation system capable of producing several grams of dust from bulk materials. The equipment was utilized in the characterization of tailings deposits from the arsenic and lead-contaminated Iron King Superfund site in Dewey-Humboldt, Arizona. Results show that metal and metalloid contaminants are more concentrated in particles of <10 μm aerodynamic diameter, which are likely to affect surrounding communities and ecosystems. In addition, we traced the transport of contaminated particles from the tailings to surrounding soils by identifying Pb and Sr isotopic signatures in soil samples. The equipment and methods developed for this assessment ensure uniform samples for further multidisciplinary studies, thus providing a tool for comprehensive representation of emission sources and associated risks of exposure.

Laboratory dust generation and size-dependent characterization of metal and metalloid-contaminated mine tailings deposits

International Nuclear Information System (INIS)

Gonzales, Patricia; Felix, Omar; Alexander, Caitlin; Lutz, Eric; Ela, Wendell; Eduardo Sáez, A.

2014-01-01

Highlights: • A laboratory dust fractionator was developed for the production of respirable dust. • The size-dependent distribution of arsenic and lead in mine tailings dust is reported. • Metal and metalloid contaminants are enriched in particles smaller than 10 μm. • Lead isotope signatures show spread of mine tailings particles onto surrounding soils. - Abstract: The particle size distribution of mine tailings material has a major impact on the atmospheric transport of metal and metalloid contaminants by dust. Implications to human health should be assessed through a holistic size-resolved characterization involving multidisciplinary research, which requires large uniform samples of dust that are difficult to collect using conventional atmospheric sampling instruments. To address this limitation, we designed a laboratory dust generation and fractionation system capable of producing several grams of dust from bulk materials. The equipment was utilized in the characterization of tailings deposits from the arsenic and lead-contaminated Iron King Superfund site in Dewey-Humboldt, Arizona. Results show that metal and metalloid contaminants are more concentrated in particles of <10 μm aerodynamic diameter, which are likely to affect surrounding communities and ecosystems. In addition, we traced the transport of contaminated particles from the tailings to surrounding soils by identifying Pb and Sr isotopic signatures in soil samples. The equipment and methods developed for this assessment ensure uniform samples for further multidisciplinary studies, thus providing a tool for comprehensive representation of emission sources and associated risks of exposure

Respirable dust measured downwind during rock dust application.

Science.gov (United States)

Harris, M L; Organiscak, J; Klima, S; Perera, I E

2017-05-01

The Pittsburgh Mining Research Division of the U.S. National Institute for Occupational Safety and Health (NIOSH) conducted underground evaluations in an attempt to quantify respirable rock dust generation when using untreated rock dust and rock dust treated with an anticaking additive. Using personal dust monitors, these evaluations measured respirable rock dust levels arising from a flinger-type application of rock dust on rib and roof surfaces. Rock dust with a majority of the respirable component removed was also applied in NIOSH's Bruceton Experimental Mine using a bantam duster. The respirable dust measurements obtained downwind from both of these tests are presented and discussed. This testing did not measure miners' exposure to respirable coal mine dust under acceptable mining practices, but indicates the need for effective continuous administrative controls to be exercised when rock dusting to minimize the measured amount of rock dust in the sampling device.

Potentiometric titration curves of aluminium salt solutions and its ...

African Journals Online (AJOL)

Potentiometric titration curves of aluminium salt solutions and its species conversion ... of aluminium salt solutions under the moderate slow rate of base injection. ... silicate radical, and organic acid radical on the titration curves and its critical ...

Microstructural characterization of fly ash particulate reinforced AA6063 aluminium alloy for aerospace applications

Science.gov (United States)

Razzaq, A. M.; Majid, D. L. Abang Abdul; Ishak, M. R.; Uday, M. B.

2017-12-01

Aluminium-fly ash (FA) particulate reinforced composites (AA6063-FA) have been used in automotive and aerospace industries because of their low density and good mechanical properties. Three different weight fraction of FA: 2%, 4% and 6% are added to AA6063 alloy using compocasting method. The effect of FA particulates on microstructure, density and compression strength of AA6063- FA composites are investigated. Field Emission Scanning Electron Microscope (FESEM) micrographs reveal that the FA particulates are uniformly distributed in AA6063 alloy. The results also show that density, compression strength and microstructure of the AA6063-FA composites are significantly influenced by the FA amount. The increase in the weight fraction of FA will improve the microstructure and enhance the compression strength. The density of AA6063-FA composites decreases as the incorporation of FA increases.

Cytotoxicity, oxidative stress and expression of adhesion molecules in human umbilical vein endothelial cells exposed to dust from paints with or without nanoparticles

DEFF Research Database (Denmark)

Mikkelsen, Lone; Jensen, Keld A; Koponen, Ismo K

2013-01-01

Abstract Nanoparticles in primary form and nanoproducts might elicit different toxicological responses. We compared paint-related nanoparticles with respect to effects on endothelial oxidative stress, cytotoxicity and cell adhesion molecule expression. Primary human umbilical vein endothelial cells...... were exposed to primary nanoparticles (fine, photocatalytic or nanosized TiO(2), aluminium silicate, carbon black, nano-silicasol or axilate) and dust from sanding reference- or nanoparticle-containing paints. Most of the samples increased cell surface expressions of vascular cell adhesion molecule-1...... (VCAM-1) and intracellular adhesion molecule-1 (ICAM-1), but paint sanding dust samples generally generated less response than primary particles of TiO(2) and carbon black. We found no relationship between the expression of adhesion molecules, cytotoxicity and production of reactive oxygen species...

Bioaccumulation of Aluminium in Hydromacrophytes in Polish Coastal Lakes

Directory of Open Access Journals (Sweden)

Senze Magdalena

2015-03-01

Full Text Available The research on aluminium content was conducted in water and on aquatic flora of Polish lakes in the central part of the coast. The study included the lakes Sarbsko, Choczewskie, Bia.e, K.odno, D.brze and Salino investigated in the summer of 2013. The examined lakes belong mainly to the direct basin of the Baltic Sea. Samples of aquatic plants and lake waters were collected. In the water samples pH and electrolytic conductivity were measured. The aluminium content was determined both in water and aquatic plants. Submerged hydromacrophyte studies included Myriophyllum alterniflorum L., Potamogeton perfoliatus L. and Ceratophyllum demersum L. Emergent hydromacrophyte studies included Phragmites australis (Cav. Trin. ex Steud., Juncus bulbosus L., Iris pseudacorus L., Eleocharis palustris (L. Roem. % Schult., Phalaris arundinacea L., Carex riparia Curt., Mentha aquatic L., Stratiotes aloides L., Alisma plantago-aquatica L., Glyceria maxima (Hartman Holmb., Sagittaria sagittifolia L., Scirpus lacustris L. and Typha angustifolia L. The purpose of this investigation was the determination of the aluminium content in submerged and emergent hydromacrophytes and also the definition of their bioaccumulative abilities. The average concentration of aluminium in water was 2.68 fęg Al dm.3. The average content of aluminium in plants was 2.8015 mg Al kg.1. The bioaccumulation factor ranged from BCF=19.74 to BCF=16619. On the basis of the analysis of the aluminium content in water and aquatic plants results show that both water and plants were characterized by a moderate level of aluminium. The recorded concentrations indicate a mid-range value and are much lower than those which are quoted for a variety of surface waters in various parts of the world.

Lake restoration with aluminium, bentonite and Phoslock: the effect on sediment stability and light attenuation

DEFF Research Database (Denmark)

Egemose, Sara; Reitzel, Kasper; Flindt, Mogens

treatments on aluminium mobility, sediment stability or light climate. A laboratory flume experiment including three shallow Danish lakes was conducted. We measured the effects of aluminium, Phoslock (a commercial product), bentonite, and a combination of bentonite/aluminium. Each treatment caused a varying...... consolidation of the sediment. The largest consolidation occurred using Phoslock- and bentonite-addition followed by bentonite/aluminium-addition, whereas aluminium alone had no effect. Sediment stability thresholds were measured before and after addition. Especially Phoslock, but also bentonite and bentonite....../aluminium increased sediment erosion threshold, with respectively 200%, 43% and 57%. Aluminium, bentonite/aluminium, and Phoslock improved the light conditions in the water phase, with respectively 60%, 57% and 50%, whereas bentonite created higher turbidity. Conclusively aluminium improved the light conditions...

Anodization of Aluminium using a fast two-step process

Indian Academy of Sciences (India)

283.6 eV. Keywords. Anodization; phosphoric acid; anodization time; anodized aluminium oxide; aluminium. ... of anodization.5–7 The AAO layer has a large band gap, good ..... transmittance increases as the anodised membrane is heated to ...

An analysis of employee exposure to organic dust at large-scale composting facilities

Science.gov (United States)

Sykes, P.; Allen, J. A.; Wildsmith, J. D.; Jones, K. P.

2009-02-01

The occupational health implications from exposure to dust, endotoxin and 1-3 β Glucan at commercial composting sites are uncertain. This study aims to establish employee exposure levels to inhalable and respirable dust, endotoxin and 1-3 β Glucan during various operational practices in the composting process. Personal samples were collected and the inhalable and respirable dust fractions were determined by gravimetric analysis. Endotoxin concentrations were determined using a Limulus Amebocyte Lysate assay (LAL). 1-3 β Glucan levels were estimated using a specific blocking agent to establish the contribution that these compounds gave to the original endotoxin assay. Employees' exposure to dust was found to be generally lower than the levels stipulated in the Control of Substances Hazardous to Health Regulations (COSHH) 2002 (as amended), (median inhalable fraction 1.08 mg/m3, min 0.25 mg/m3 max 10.80 mg/m3, median respirable fraction 0.05 mg/m3, min 0.02 mg/m3, max 1.49 mg/m3). Determination of the biological component of the dust showed that employees' exposures to endotoxin were elevated (median 31.5 EU/m3, min 2.00 EU/m3, max 1741.78 EU/m3), particularly when waste was agitated (median 175.0 EU/m3, min 2.03 EU/m3, max 1741.78 EU/m3). Eight out of 32 (25%) of the personal exposure data for endotoxin exceeded the 200 EU/m3 temporary legal limit adopted in the Netherlands and thirteen out of 32 (40.6%) exceeded the suggested 50 EU/m3 guidance level suggested to protect workers from respiratory health effects. A significant correlation was observed between employee inhalable dust exposure and personal endotoxin concentration (r = 0.728, phealth risks associated with endotoxin exposure at composting sites. Employee exposure levels and dose-response disease mechanisms are not well understood at this present time. Consequently, in light of this uncertainty, it is recommended that a precautionary approach be adopted in managing the potential health risks associated

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

Science.gov (United States)

Akay, Cemal; Kalman, Süleyman; Dündaröz, Ruşen; Sayal, Ahmet; Aydin, Ahmet; Ozkan, Yalçin; Gül, Hüsamettin

2008-05-01

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

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

Science.gov (United States)

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

2015-01-01

Metal risk assessment of industrialized harbors and coastal marine waters requires the application of robust water quality guidelines to determine the likelihood of biological impacts. Currently there is no such guideline available for aluminium in marine waters. A water quality guideline of 24 µg total Al/L has been developed for aluminium in marine waters based on chronic 10% inhibition or effect concentrations (IC10 or EC10) and no-observed-effect concentrations (NOECs) from 11 species (2 literature values and 9 species tested including temperate and tropical species) representing 6 taxonomic groups. The 3 most sensitive species tested were a diatom Ceratoneis closterium (formerly Nitzschia closterium; IC10 = 18 µg Al/L, 72-h growth rate inhibition) 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. © 2014 SETAC.

Cancer risk among workers of a secondary aluminium smelter.

Science.gov (United States)

Maltseva, A; Serra, C; Kogevinas, M

2016-07-01

Cancer risk in secondary aluminium production is not well described. Workers in this industry are exposed to potentially carcinogenic agents from secondary smelters that reprocess aluminium scrap. To evaluate cancer risk in workers in a secondary aluminium plant in Spain. Retrospective cohort study of male workers employed at an aluminium secondary smelter (1960-92). Exposure histories and vital status through 2011 were obtained through personal interviews and hospital records, respectively. Standardized mortality (SMRs) and incidence ratios (SIRs) were calculated. The study group consisted of 98 workers. We found increased incidence and mortality from bladder cancer [SIR = 2.85, 95% confidence interval (CI) 1.23-5.62; SMR = 5.90, 95% CI 1.58-15.11]. Increased incidence was also observed for prostate cancer and all other cancers but neither were statistically significant. No increased risk was observed for lung cancer. Results of this study suggest that work at secondary aluminium smelters is associated with bladder cancer risk. Identification of occupational carcinogens in this industry is needed. © The Author 2016. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Deposition of aluminium nanoparticles using dense plasma focus device

International Nuclear Information System (INIS)

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

2010-01-01

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

Long-lived Dust Asymmetries at Dead Zone Edges in Protoplanetary Disks

Energy Technology Data Exchange (ETDEWEB)

Miranda, Ryan [Cornell Center for Astrophysics and Planetary Science, Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States); Li, Hui; Li, Shengtai; Jin, Sheng, E-mail: rjm456@cornell.edu [Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2017-02-01

A number of transition disks exhibit significant azimuthal asymmetries in thermal dust emission. One possible origin for these asymmetries is dust trapping in vortices formed at the edges of dead zones. We carry out high-resolution, two-dimensional hydrodynamic simulations of this scenario, including the effects of dust feedback. We find that, although feedback weakens the vortices and slows down the process of dust accumulation, the dust distribution in the disk can nonetheless remain asymmetric for many thousands of orbits. We show that even after 10{sup 4} orbits, or 2.5 Myr when scaled to the parameters of Oph IRS 48 (a significant fraction of its age), the dust is not dispersed into an axisymmetric ring, in contrast to the case of a vortex formed by a planet. This is because accumulation of mass at the dead zone edge constantly replenishes the vortex, preventing it from being fully destroyed. We produce synthetic dust emission images using our simulation results. We find that multiple small clumps of dust may be distributed azimuthally. These clumps, if not resolved from one another, appear as a single large feature. A defining characteristic of a disk with a dead zone edge is that an asymmetric feature is accompanied by a ring of dust located about twice as far from the central star.

Corrosion issues of powder coated AA6060 aluminium profiles

DEFF Research Database (Denmark)

Din, Rameez Ud; Valgarðsson, Smári; Jellesen, Morten Stendahl

2015-01-01

In this study detailed microstructural investigation of the reason for unexpected corrosion of powder coated aluminium alloy AA6060 windows profiles has been performed. The results from this study reveals that the failure of the window profiles was originated from the surface defects present...... on the extruded AA6060 aluminium profile after metallurgical process prior to powder coating. Surface defects are produced due to intermetallic particles in the alloy, which disturb the flow during the extrusion process. The corrosion mechanism leading to the failure of the powder coated AA6060 aluminium profiles...

Iron content and solubility in dust from high-alpine snow along a north-south transect of High Asia

Directory of Open Access Journals (Sweden)

Guangjian Wu

2012-04-01

Full Text Available This study describes the dissolved and insoluble iron fraction of dust (mineral aerosol in high-alpine snow samples collected along a north-south transect across High Asia (Eastern Tien Shan, Qilian Shan, and Southern Tibetan Plateau. This dust provides the basic chemical properties of mid- and high-level tropospheric Asian dust that can supply the limiting iron nutrient for phytoplankton growth in the North Pacific. The iron content in Asian dust averages 4.95% in Eastern Tien Shan, 3.38–5.41% along Qilian Shan and 3.85% in the Southern Tibetan Plateau. The iron fractional solubility averages about 0.25% in Eastern Tien Shan, 0.05–2% along Qilian Shan and 1.5% in the Southern Tibetan Plateau. Among the controlling factors that can affect iron solubility in Asian dust, such as dust composition and particle grain size, acidity seems to be the most significant and can increase the iron solubility by one or two orders of magnitude with acidification of pH=0.66. Our results reveal that iron solubility of dust in the remote downwind sites is higher than that in high-alpine snow, confirming the strong pH-dependence of iron solubility, and indicating that Asian dust shows a large variation in iron solubility on a regional scale.

Light scattering and absorption properties of dust particles retrieved from satellite measurements

International Nuclear Information System (INIS)

Hu, R.-M.; Sokhi, R.S.

2009-01-01

We use the radiative transfer model and chemistry transport model to improve our retrievals of dust optical properties from satellite measurements. The optical depth and absorbing optical depth of mineral dust can be obtained from our improved retrieval algorithm. We find the nonsphericity and absorption of dust particles strongly affect the scattering signatures such as phase function and polarization at the ultraviolet wavelengths. From our retrieval results, we find the high levels of dust concentration occurred over most desert regions such as Saharan and Gobi deserts. The dust absorption is found to be sensitive to mineral chemical composition, particularly the fraction of strongly absorbing dust particles. The enhancement of polarization at the scattering angles exceeding 120 0 is found for the nonspherical dust particles. If the polarization is neglected in the radiative transfer calculation, a maximum 50 percent error is introduced for the case of forward scattering and 25 percent error for the case of backscattering. We suggest that the application of polarimeter at the ultraviolet wavelengths has the great potential to improve the satellite retrievals of dust properties. Using refined optical model and radiative transfer model to calculate the solar radiative forcing of dust aerosols can reduce the uncertainties in aerosol radiative forcing assessment.

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

Science.gov (United States)

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

2013-01-01

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. 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. 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. 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.

Synthesis, properties, and assimilation methods of aluminium hydride

International Nuclear Information System (INIS)

Mirsaidov, U.M.

2013-01-01

We have discovered a new source of aluminium hydride-conversion of tetrahydrofurane under influence of halogenous alkyls. We have proposed the chlorbenzene method of synthesis of AlH 3 , which excludes adhesion and ensure high quality of the product with respect to its purity, thermal stability, habits of crystals (round shape), and granulometric composition. We determined capability of benzyl chloride to fix AlH 4 -groups by the way of complexes formation. This allows increasing efficient concentration of AlH 3 solutions and their productivity. We have carried out 'direct' crystallization of aluminium hydride in one stage using interaction of binary metal hydride with aluminium chloride in the medium of ether-toluene at 60-100 d ig C a nd using solvent distillation. In the reaction of Li H with AlCl 3 , we achieved output of pure crystal AlH 3 of hexagonal modification, which was close to quantitative. We have discovered the assimilation methods of aluminium hydride in carrying out of solid-phase chemical reactions. (author)

Indentation of aluminium foam at low velocity

Directory of Open Access Journals (Sweden)

Shi Xiaopeng

2015-01-01

Full Text Available The indentation behaviour of aluminium foams at low velocity (10 m/s ∼ 30 m/s was investigated both in experiments and numerical simulation in this paper. A flat-ended indenter was used and the force-displacement history was recorded. The Split Hopkinson Pressure bar was used to obtain the indentation velocity and forces in the dynamic experiments. Because of the low strength of the aluminium foam, PMMA bar was used, and the experimental data were corrected using Bacon's method. The energy absorption characteristics varying with impact velocity were then obtained. It was found that the energy absorption ability of aluminium foam gradually increases in the quasi-static regime and shows a significant increase at ∼10 m/s velocity. Numerical simulation was also conducted to investigate this process. A 3D Voronoi model was used and models with different relative densities were investigated as well as those with different failure strain. The indentation energy increases with both the relative density and failure strain. The analysis of the FE model implies that the significant change in energy absorption ability of aluminium foam in indentation at ∼10 m/s velocity may be caused by plastic wave effect.

Improvement of photodynamic activity of aluminium sulphophthalocyanine due to biotinylation

Science.gov (United States)

Meerovich, Irina G.; Jerdeva, Victoria V.; Derkacheva, Valentina M.; Meerovich, Gennadii A.; Lukyanets, Eugeny A.; Kogan, Eugenia A.; Savitsky, Alexander P.

2003-09-01

The photodynamic activity of dibiotinylated aluminium sulphophthalocyanine in vitro and in vivo were studied. It was obtained that in vitro dibiotinylated aluminium sulphophthalocyanine provides the effective damage of small cell lung carcinoma OAT-75. In vivo dibiotinylated aluminium sulphophthalocyanine causes destruction of tumor (Erlich carcinoma), results in total necrosis of tumor tissue and expresses vascular damage (trombosis and destruction of vascular walls) even in concentration 0.25 mg/kg of a body weight.

Iron content and solubility in dust from high-alpine snow along a north-south transect of High Asia

OpenAIRE

Wu, Guangjian; Zhang, Chenglong; Li, Zhongqin; Zhang, Xuelei; Gao, Shaopeng

2012-01-01

This study describes the dissolved and insoluble iron fraction of dust (mineral aerosol) in high-alpine snow samples collected along a north-south transect across High Asia (Eastern Tien Shan, Qilian Shan, and Southern Tibetan Plateau). This dust provides the basic chemical properties of mid- and high-level tropospheric Asian dust that can supply the limiting iron nutrient for phytoplankton growth in the North Pacific. The iron content in Asian dust averages 4.95% in Eastern Tien Shan, 3.38–5...

Aluminium supplier selection for the automotive parts manufacturer

Directory of Open Access Journals (Sweden)

M. Cieśla

2016-04-01

Full Text Available This paper presents a methodology for selection of the optimal sources of supply, which is also known as the problem of supplier selection. Theoretical considerations are expanded with research related to aluminium supplier selection for a hypothetical manufacturer of aluminium parts for transportation equipment located in Poland. Evaluation of five suppliers of aluminium from Poland, Germany and Slovenia has been conducted using a weighted scoring method, a strengths and weaknesses method and a graphical method. Choosing the best offer and prioritizing suppliers allows not only the most rational decision in the field of supply logistics to be taken but also the quality of service in the metallurgical industry to be improved.

PERSPECTIVE: Dust, fertilization and sources

Science.gov (United States)

Remer, Lorraine A.

2006-11-01

fraction that arrives at another continent [2]. At the deposition end of the chain, it is still unclear how the limited minerals in the dust such as iron are released for uptake by organisms either on land or in the ocean. Not all dust deposited into oceans results in a phytoplankton bloom. The process requires a chemical pathway that mobilizes a fraction of the iron into soluble form. Meskhidze et al [3] show that phytoplankton blooms following dust transport from the Gobi desert in Asia into the Pacific ocean result in a phytoplankton bloom only if the dust is accompanied by high initial SO2-to-dust ratios, suggesting that sulfuric acid coatings on the dust particle mobilize the embedded iron in the dust for phytoplankton uptake. Quantifying transport, deposition and nutrient availability are the latter ends of a puzzle that must begin by identifying and quantifying dust emission at the sources. The emission process is complex at the microscale requiring the right conditions for saltation and bombardment, which makes identification and inclusion of sources in global transport models very difficult. The result is that estimates of annual global dust emissions range from 1000 to 3000 Tg per year [4]. Even as global estimates of dust emissions are uncertain, localizing the sources brings even greater uncertainty. It has been recognized for several years that dust sources are not uniformly distributed over the arid regions of the Earth, but are regulated to topographic lows associated with dried lake deposits [5]. Using aerosol information from satellites, a comprehensive map of the world's source regions shows sources localized to specific areas of the Earth's arid regions [6]. Still these maps suggest broad emission sources covering several degrees of latitude and longitude. In the paper by Koren and co-authors [7] appearing in this issue, one particular dust source, the Bodélé depression in Chad, is analyzed in detail. They find that the specific topography of the

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

Science.gov (United States)

Mudge, David W; Johnson, David W; Hawley, Carmel M; Campbell, Scott B; Isbel, Nicole M; van Eps, Carolyn L; Petrie, James J B

2011-05-13

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. 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. 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

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

Directory of Open Access Journals (Sweden)

van Eps Carolyn L

2011-05-01

Full Text Available Abstract 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

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

Science.gov (United States)

2011-01-01

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

Dust Composition in Climate Models: Current Status and Prospects

Science.gov (United States)

Pérez García-Pando, C.; Miller, R. L.; Perlwitz, J. P.; Kok, J. F.; Scanza, R.; Mahowald, N. M.

2015-12-01

Mineral dust created by wind erosion of soil particles is the dominant aerosol by mass in the atmosphere. It exerts significant effects on radiative fluxes, clouds, ocean biogeochemistry, and human health. Models that predict the lifecycle of mineral dust aerosols generally assume a globally uniform mineral composition. However, this simplification limits our understanding of the role of dust in the Earth system, since the effects of dust strongly depend on the particles' physical and chemical properties, which vary with their mineral composition. Hence, not only a detailed understanding of the processes determining the dust emission flux is needed, but also information about its size dependent mineral composition. Determining the mineral composition of dust aerosols is complicated. The largest uncertainty derives from the current atlases of soil mineral composition. These atlases provide global estimates of soil mineral fractions, but they are based upon massive extrapolation of a limited number of soil samples assuming that mineral composition is related to soil type. This disregards the potentially large variability of soil properties within each defined soil type. In addition, the analysis of these soil samples is based on wet sieving, a technique that breaks the aggregates found in the undisturbed parent soil. During wind erosion, these aggregates are subject to partial fragmentation, which generates differences on the size distribution and composition between the undisturbed parent soil and the emitted dust aerosols. We review recent progress on the representation of the mineral and chemical composition of dust in climate models. We discuss extensions of brittle fragmentation theory to prescribe the emitted size-resolved dust composition, and we identify key processes and uncertainties based upon model simulations and an unprecedented compilation of observations.

Decomposition of pre calcined aluminium silicate ores of Afghanistan by hydrochloric acid

International Nuclear Information System (INIS)

Khomidi, A.K.; Mamatov, E.D.

2015-01-01

Present article is devoted to decomposition of pre calcined aluminium silicate ores of Afghanistan by hydrochloric acid. The physicochemical properties of initial aluminium silicate ores were studied by means of X-ray phase, differential thermal and silicate analysis. The chemical composition of aluminium containing ores was determined. The optimal conditions of interaction of initial and pre calcined siallites with hydrochloric acid were defined. The kinetics of acid decomposition of aluminium silicate ores was studied as well.

An interesting and efficient green corrosion inhibitor for aluminium ...

African Journals Online (AJOL)

An interesting and efficient green corrosion inhibitor for aluminium from extracts of ... Journal Home > Vol 13, No 1 (2014) > ... possible applications in metal surface anodizing and surface coating in industries. Keywords: Moringa oleifera, Aluminium, Hydrochloric acid, Langmuir isotherm, Plant extracts, Corrosion inhibition ...

Power distribution: conductors in aluminium

International Nuclear Information System (INIS)

Schmid, R.

2007-01-01

This article takes a look at the use of aluminium conductors in medium and low-voltage cables. The author discusses how the increasing price of copper has led to the increasing use of aluminium as a material for the production of the conductors used in medium and low-voltage power cables. Aid is provided that is to help purchasers make the correct decisions when buying medium and low-voltage cables. The current market situation is examined and the appropriate norms are looked at. Technical data and economic aspects are discussed, both for medium and low-voltage applications. The electrical characteristics of the type of cable to be used are examined and discussed

Spectrographic determination of trace impurities in reactor grade aluminium

International Nuclear Information System (INIS)

Chandola, L.C.; Machado, I.J.

1975-01-01

A spectrographic method enabling the determination of 21 trace impurities in aluminium oxide is described. The technique involves mixing the sample with graphite buffer in the ratio 1:1, loading it in a graphite electrode and arcing it for 30 sec. in a dc arc to 10 A current against a pointed graphite cathode. The spectra are photographed on Ilford N.30 emulsion employing a large quartz spectrograph. The aluminium line at 2669.2 A 0 serves as the internal standard. The impurities determined are Ag, B, Bi, Cd, Co, Cr, Cu, Fe, Ga, In, Mg, Mo, Ni, Pb, Sb, Si, Sn, Ti, V and Zn. The sensitivity varies from 5 to 100 ppm and the precision from +- 5 to +- 22% for different elements. A method for converting aluminium metal to aluminium oxide is described. It is found that boron is not lost during this conversion. (author)

COSMIC EVOLUTION OF DUST IN GALAXIES: METHODS AND PRELIMINARY RESULTS

International Nuclear Information System (INIS)

Bekki, Kenji

2015-01-01

We investigate the redshift (z) evolution of dust mass and abundance, their dependences on initial conditions of galaxy formation, and physical correlations between dust, gas, and stellar contents at different z based on our original chemodynamical simulations of galaxy formation with dust growth and destruction. In this preliminary investigation, we first determine the reasonable ranges of the most important two parameters for dust evolution, i.e., the timescales of dust growth and destruction, by comparing the observed and simulated dust mass and abundances and molecular hydrogen (H 2 ) content of the Galaxy. We then investigate the z-evolution of dust-to-gas ratios (D), H 2 gas fraction (f H 2 ), and gas-phase chemical abundances (e.g., A O = 12 + log (O/H)) in the simulated disk and dwarf galaxies. The principal results are as follows. Both D and f H 2 can rapidly increase during the early dissipative formation of galactic disks (z ∼ 2-3), and the z-evolution of these depends on initial mass densities, spin parameters, and masses of galaxies. The observed A O -D relation can be qualitatively reproduced, but the simulated dispersion of D at a given A O is smaller. The simulated galaxies with larger total dust masses show larger H 2 and stellar masses and higher f H 2 . Disk galaxies show negative radial gradients of D and the gradients are steeper for more massive galaxies. The observed evolution of dust masses and dust-to-stellar-mass ratios between z = 0 and 0.4 cannot be reproduced so well by the simulated disks. Very extended dusty gaseous halos can be formed during hierarchical buildup of disk galaxies. Dust-to-metal ratios (i.e., dust-depletion levels) are different within a single galaxy and between different galaxies at different z

COSMIC EVOLUTION OF DUST IN GALAXIES: METHODS AND PRELIMINARY RESULTS

Energy Technology Data Exchange (ETDEWEB)

Bekki, Kenji [ICRAR, M468, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009 (Australia)

2015-02-01

We investigate the redshift (z) evolution of dust mass and abundance, their dependences on initial conditions of galaxy formation, and physical correlations between dust, gas, and stellar contents at different z based on our original chemodynamical simulations of galaxy formation with dust growth and destruction. In this preliminary investigation, we first determine the reasonable ranges of the most important two parameters for dust evolution, i.e., the timescales of dust growth and destruction, by comparing the observed and simulated dust mass and abundances and molecular hydrogen (H{sub 2}) content of the Galaxy. We then investigate the z-evolution of dust-to-gas ratios (D), H{sub 2} gas fraction (f{sub H{sub 2}}), and gas-phase chemical abundances (e.g., A {sub O} = 12 + log (O/H)) in the simulated disk and dwarf galaxies. The principal results are as follows. Both D and f{sub H{sub 2}} can rapidly increase during the early dissipative formation of galactic disks (z ∼ 2-3), and the z-evolution of these depends on initial mass densities, spin parameters, and masses of galaxies. The observed A {sub O}-D relation can be qualitatively reproduced, but the simulated dispersion of D at a given A {sub O} is smaller. The simulated galaxies with larger total dust masses show larger H{sub 2} and stellar masses and higher f{sub H{sub 2}}. Disk galaxies show negative radial gradients of D and the gradients are steeper for more massive galaxies. The observed evolution of dust masses and dust-to-stellar-mass ratios between z = 0 and 0.4 cannot be reproduced so well by the simulated disks. Very extended dusty gaseous halos can be formed during hierarchical buildup of disk galaxies. Dust-to-metal ratios (i.e., dust-depletion levels) are different within a single galaxy and between different galaxies at different z.

Spectral- and size-resolved mass absorption efficiency of mineral dust aerosols in the shortwave spectrum: a simulation chamber study

Directory of Open Access Journals (Sweden)

L. Caponi

2017-06-01

Full Text Available This paper presents new laboratory measurements of the mass absorption efficiency (MAE between 375 and 850 nm for 12 individual samples of mineral dust from different source areas worldwide and in two size classes: PM10. 6 (mass fraction of particles of aerodynamic diameter lower than 10.6 µm and PM2. 5 (mass fraction of particles of aerodynamic diameter lower than 2.5 µm. The experiments were performed in the CESAM simulation chamber using mineral dust generated from natural parent soils and included optical and gravimetric analyses. The results show that the MAE values are lower for the PM10. 6 mass fraction (range 37–135  ×  10−3 m2 g−1 at 375 nm than for the PM2. 5 (range 95–711  ×  10−3 m2 g−1 at 375 nm and decrease with increasing wavelength as λ−AAE, where the Ångström absorption exponent (AAE averages between 3.3 and 3.5, regardless of size. The size independence of AAE suggests that, for a given size distribution, the dust composition did not vary with size for this set of samples. Because of its high atmospheric concentration, light absorption by mineral dust can be competitive with black and brown carbon even during atmospheric transport over heavy polluted regions, when dust concentrations are significantly lower than at emission. The AAE values of mineral dust are higher than for black carbon (∼ 1 but in the same range as light-absorbing organic (brown carbon. As a result, depending on the environment, there can be some ambiguity in apportioning the aerosol absorption optical depth (AAOD based on spectral dependence, which is relevant to the development of remote sensing of light-absorbing aerosols and their assimilation in climate models. We suggest that the sample-to-sample variability in our dataset of MAE values is related to regional differences in the mineralogical composition of the parent soils. Particularly in the PM2. 5 fraction, we found a strong

Friction and corrosion resistance of sputter deposited supersaturated metastable aluminium-molybdenum alloys

Energy Technology Data Exchange (ETDEWEB)

Abu-Zeid, O.A. [Univ. of the United Arab Emirates, Al-Ain (United Arab Emirates). Dept. of Mech. Eng.; Bates, R.I. [Design, Mfg. and Marketing Research Inst., Univ. of Salford (United Kingdom)

1996-12-15

Two closed field unbalanced magnetrons with targets of aluminium and molybdenum have been used for the co-deposition of aluminium-molybdenum coatings with different compositions. A pin on disk machine and a computer controlled potentiostat have been used to evaluate respectively, the tribological and corrosion properties of the deposited alloys. Results have shown that introducing molybdenum into aluminium coatings improves their poor tribological properties. Aluminium-molybdenum coatings with different compositions have shown low wear behaviour and for coatings with high molybdenum contents (> 80%) friction coefficients against steel, as low as 0.18 have been obtained. The addition of molybdenum into aluminium coatings has reduced their corrosion tendency and corrosion current density in a marine environment. (orig.)

Towards toxicokinetic modelling of aluminium exposure from adjuvants in medicinal products.

Science.gov (United States)

Weisser, Karin; Stübler, Sabine; Matheis, Walter; Huisinga, Wilhelm

2017-08-01

As a potentially toxic agent on nervous system and bone, the safety of aluminium exposure from adjuvants in vaccines and subcutaneous immune therapy (SCIT) products has to be continuously re-evaluated, especially regarding concomitant administrations. For this purpose, knowledge on absorption and disposition of aluminium in plasma and tissues is essential. Pharmacokinetic data after vaccination in humans, however, are not available, and for methodological and ethical reasons difficult to obtain. To overcome these limitations, we discuss the possibility of an in vitro-in silico approach combining a toxicokinetic model for aluminium disposition with biorelevant kinetic absorption parameters from adjuvants. We critically review available kinetic aluminium-26 data for model building and, on the basis of a reparameterized toxicokinetic model (Nolte et al., 2001), we identify main modelling gaps. The potential of in vitro dissolution experiments for the prediction of intramuscular absorption kinetics of aluminium after vaccination is explored. It becomes apparent that there is need for detailed in vitro dissolution and in vivo absorption data to establish an in vitro-in vivo correlation (IVIVC) for aluminium adjuvants. We conclude that a combination of new experimental data and further refinement of the Nolte model has the potential to fill a gap in aluminium risk assessment. Copyright © 2017 Elsevier Inc. All rights reserved.

RESPONSE OF PHENOLIC METABOLISM INDUCED BY ALUMINIUM TOXICITY IN FAGOPYRUM ESCULENTUM MOENCH. PLANTS.

Science.gov (United States)

Smirnov, O E; Kosyan, A M; Kosyk, O I; Taran, N Yu

2015-01-01

Buckwheat genus (Fagopyrum Mill.) is one of the aluminium tolerant taxonomic units of plants. The aim of the study was an evaluation of the aluminium (50 μM effect on phenolic accumulation in various parts of buckwheat plants (Fagopyrum esculentum Moench). Detection of increasing of total phenolic content, changes in flavonoid and anthocyanin content and phenylalanine ammonia-lyase activity (PAL) were revealed over a period of 10 days of exposure to aluminium. The most significant effects of aluminium treatment on phenolic compounds accumulation were total phenolic content increasing (by 27.2%) and PAL activity rising by 2.5 times observed in leaves tissues. Received data could be helpful to understand the aluminium tolerance principles and relationships of phenolic compounds to aluminium phytotoxicity.

Reducing dust and allergen exposure in bakeries

Directory of Open Access Journals (Sweden)

Howard J Mason

2017-12-01

Full Text Available Bakers have a continuing high incidence of occupational allergic asthma. In factory bakeries they are exposed not only to flour dust containing allergens, but also improvers whose ingredients enhance the strength and workability of the dough and its speed of rising. Improvers are flour-based but can contain added soya, fungal or bacterial enzymes that are also allergenic, as well as vegetable oil, calcium sulphate/silicate and organic esters. This study investigated the dustiness of the components used in factory bakeries and whether altering improver ingredients could reduce dust and allergen exposure. A standardised rotating drum test was employed on the individual components, as well as a representative improver and three practicable improver modifications by decreasing calcium sulphate, calcium silicate or increasing oil content. Levels of dust, the allergens wheat flour amylase inhibitor (WAAI and soya trypsin inhibitor (STI were measured in the generated inhalable, thoracic and respirable sized fractions. A “scooping and pouring” workplace simulation was also performed. Initial tests showed that dustiness of several wheat flours was relatively low, and even lower for soya flour, but increased in combination with some other improver components. All three improver modifications generally reduced levels of dust, STI and WAAI, but increasing oil content significantly decreased dust and STI in comparison to the standard improver and those improvers with reduced calcium silicate or sulphate. The simulation demonstrated that increased oil content reduced inhalable levels of gravimetric dust, STI and WAAI. Changing improver formulation, such as increasing oil content of flour by a small amount, may represent a simple, practical method of reducing bakery workers’ exposure to dust and allergens where improvers are used. It may be a useful adjunct to engineering control, changes to work practices and appropriate training in reducing the risk to

Modelling of heterogeneous clustering in aluminium

International Nuclear Information System (INIS)

Smith, A.E.; Bourgeois, L.; Nie, J.-F.; Muddle, B.C.

2003-01-01

Full text: Ab initio modelling of heterogeneous clustering in aluminium has been carried out in order to study the precipitation hardening of alloys. This process is based on the addition of small amounts of solute element to the pure metal. With increasing computational power, atomic scale effects can now be better simulated to determine the nature of the hardening mechanism. Comparisons are made between results obtained from two computational packages. These are the Linear Augmented Plane Wave WEEN2K and the plane wave pseudopotential density functional theory package fhi98md. The study of the optimal geometry of very small size clusters inside aluminium has begun with the testing of initial convergence conditions by determination of binding energies for a variety of super cell sizes of the aluminium host crystal. These are compared with total energy calculations for small size precipitates of copper and transition metals of fixed geometry. Such local optimal determinations are seen as precursors to full Monte Carlo calculations of the notional best local geometry for larger precipitates

Synthesis of aluminium nanoparticles by arc evaporation of an ...

Indian Academy of Sciences (India)

Administrator

Abstract. Aluminium nanoparticles (Al Nps) are synthesized using arc discharge method by applying direct current between aluminium electrodes in liquid environment without any use of vacuum equipment, heat exchangers, high temperatures furnaces and inert gases. After synthesis of Al Nps, in situ coating process on.

The varied functions of aluminium-activated malate transporters–much more than aluminium resistance

Science.gov (United States)

Palmer, Antony J.; Baker, Alison; Muench, Stephen P.

2016-01-01

The ALMT (aluminium-activated malate transporter) family comprises a functionally diverse but structurally similar group of ion channels. They are found ubiquitously in plant species, expressed throughout different tissues, and located in either the plasma membrane or tonoplast. The first family member identified was TaALMT1, discovered in wheat root tips, which was found to be involved in aluminium resistance by means of malate exudation into the soil. However, since this discovery other family members have been shown to have many other functions such as roles in stomatal opening, general anionic homoeostasis, and in economically valuable traits such as fruit flavour. Recent evidence has also shown that ALMT proteins can act as key molecular actors in GABA (γ-aminobutyric acid) signalling, the first evidence that GABA can act as a signal transducer in plants. PMID:27284052

DUST PRODUCTION AND PARTICLE ACCELERATION IN SUPERNOVA 1987A REVEALED WITH ALMA

Energy Technology Data Exchange (ETDEWEB)

Indebetouw, R.; Chevalier, R. [Department of Astronomy, University of Virginia, PO Box 400325, Charlottesville, VA 22904 (United States); Matsuura, M.; Barlow, M. J. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Dwek, E. [NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States); Zanardo, G. [International Centre for Radio Astronomy Research (ICRAR), University of Western Australia, Crawley, WA 6009 (Australia); Baes, M. [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent (Belgium); Bouchet, P. [CEA-Saclay, F-91191 Gif-sur-Yvette (France); Burrows, D. N. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Clayton, G. C. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Fransson, C.; Lundqvist, P. [Department of Astronomy and the Oskar Klein Centre, Stockholm University, AlbaNova, SE-106 91 Stockholm (Sweden); Gaensler, B. [Australian Research Council Centre of Excellence for All-sky Astrophysics (CAASTRO) (Australia); Kirshner, R. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Lakićević, M. [Lennard-Jones Laboratories, Keele University, ST5 5BG (United Kingdom); Long, K. S.; Meixner, M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Martí-Vidal, I. [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, SE-43992 Onsala (Sweden); Marcaide, J. [Universidad de Valencia, C/Dr. Moliner 50, E-46100 Burjassot (Spain); McCray, R., E-mail: remy@virginia.edu [Department of Astrophysical and Planetary Sciences, University of Colorado at Boulder, UCB 391, Boulder, CO 80309 (United States); and others

2014-02-10

Supernova (SN) explosions are crucial engines driving the evolution of galaxies by shock heating gas, increasing the metallicity, creating dust, and accelerating energetic particles. In 2012 we used the Atacama Large Millimeter/Submillimeter Array to observe SN 1987A, one of the best-observed supernovae since the invention of the telescope. We present spatially resolved images at 450 μm, 870 μm, 1.4 mm, and 2.8 mm, an important transition wavelength range. Longer wavelength emission is dominated by synchrotron radiation from shock-accelerated particles, shorter wavelengths by emission from the largest mass of dust measured in a supernova remnant (>0.2 M {sub ☉}). For the first time we show unambiguously that this dust has formed in the inner ejecta (the cold remnants of the exploded star's core). The dust emission is concentrated at the center of the remnant, so the dust has not yet been affected by the shocks. If a significant fraction survives, and if SN 1987A is typical, supernovae are important cosmological dust producers.

Measuring Dust Emission from the Mojave Desert (USA) by Daily Remote-Camera Observations and Wind-Erosion Measurements: Bearing on "Unseen" Sources and Global Dust Abundance

Science.gov (United States)

Reynolds, R. L.; Urban, F.; Goldstein, H. L.; Fulton, R.

2017-12-01

A large gap in understanding the effects of atmospheric dust at all spatial scales is uncertainty about how much and whence dust is emitted annually. Digital recording of dust emission at high spatial and temporal resolution would, together with periodic flux measurements, support improved estimates of local-scale dust flux where infrastructure could support remote internet enabled cameras. Such recording would also elucidate wind-erosion dynamics when combined with meteorological data. Remote camera recording of dust-emitting settings on and around Soda Lake (Mojave Desert) was conducted every 15 minutes during daylight between 10 Nov. 2010 and 31 Dec. 2016 and images uploaded to a web server. Examination of 135,000 images revealed frequent dust events, termed "dust days" when plumes obscured mountains beyond source areas. Such days averaged 68 (sd=10) per year (2011 through 2016). We examined satellite retrievals (MODIS, GOES) for dust events during six cloudless days of highest and longest duration dust emission but none were observed. From Apr. 2000 through May 2013, aeolian sediments collected at three sites were sampled and weighed. Estimates of the emitted mass of silt- and clay-size fractions were made on the basis of measured horizontal mass flux, particle sizes of sediment in collectors, and roughly determined areas of dust generation. Over this period, nearly 4 Tg yr-1 of dust (as particulate matter flood in the basin in late Dec. 2010 that deposited flood sediment across the lake basin. Increased emission was likely related to the availability of fresh, unanchored flood sediment. Within the Mojave and Great Basin deserts of North America, many settings akin to those at Soda Lake similarly emit dust that is rarely detected in satellite retrievals. These findings strongly imply that local and regional dust emissions from western North America are far underestimated and that, by extension to relatively small dust-source areas across all drylands, global

Improvement of cement plant dust emission by bag filter system

Science.gov (United States)

Wahyu Purnomo, Chandra; Budhijanto, Wiratni; Alfisyah, Muziibu; Triyono

2018-03-01

The limestone quarry in PT Indocement Tunggal Prakarsa (ITP) in Cirebon is considered as a complex quarry in terms of chemical composition and material hardness. From the beginning of the plant operation up to the end of 2015, the dust removal was rely on electrostatic precipitator (EP) system. Whenever limestone from specific quarry zones were incorporated into Raw Mill (RM) feed or there was an upset condition, the dust emission increased significantly. Beside higher demand of electricity, an EP system requires lower gas inlet temperature in order to remove the dust effectively which requires larger cooling water in the previous gas conditioning tower to cool down gas from 400 °C to about 100 °C. By considering the drawbacks, the EP system was replaced by a bag filter (BF) system. The BF allows higher temperature of gas inlet and it has higher dust removal efficiency. In this study, the efficiency of the two different dust removal systems is compared. The effect of process variables i.e. RM feed, kiln feed, inlet temperature and pressure, and small size particle fraction to the dust emission are studied by multivariate linier regression analysis. It is observed that the BF system can reduce significantly the dust emission from 30 to 6 mg/m3 and in the same time reducing CO2 emission by 0.24 ton/year from the electricity consumption saving.

Light-weight aluminium bridges and bridge decks. An overview of recent applications

NARCIS (Netherlands)

Maljaars, J.; Soetens, F.; Kluyver, D. de

2008-01-01

The last decades have shown a large increase in the application of aluminium alloys for light-weight bridges. For bridge construction, aluminium alloys have some specific advantages, but also some points of attention. This paper deals with some recent projects of aluminium bridges, and for these

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

Science.gov (United States)

Polini, W.; Sorrentino, L.

2003-05-01

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

Effect of iron and silicon in aluminium and its alloys

International Nuclear Information System (INIS)

Kovacs, I.

1990-01-01

The iron and silicon are the main impurities in aluminium, they are always present in alloys made from commercially pure base material. The solid solubility of iron in aluminium is very low, therefore its largest amount forms intermetallic compounds the kind of which depends strongly on the other impurities of alloying elements. Although the solid solubility of silicon is much larger than that of the iron, it is the constituent of both the primary and the secondary particles, the structure of which depends in general on the iron-silicon concentration ratio. These Fe and Si containing particles can cause various and basic changes in the macroscopic properties of the alloy. Since commercially pure aluminium has extensive consumer and industrial use, it is very important to know, not only from scientific but also from practical point of view, the effect of iron and silicon on the physical and mechanical properties of aluminium and its alloys. The aim of the ''International Workshop on the Effect of Iron and Silicon in Aluminium and its Alloys'' was to clarify the present knowledge on this subject. The thirty papers presented at the Workshop and collected in this Proceedings cover many important fields of the subject. I hope that they will contribute to both the deeper understanding of the related phenomena and the improvement of technologies for producing better aluminium alloys

Microstructure and properties of aluminium-aluminium oxide graded composite materials

Science.gov (United States)

Kamaruzaman, F. F.; Nuruzzaman, D. M.; Ismail, N. M.; Hamedon, Z.; Iqbal, A. K. M. A.; Azhari, A.

2018-03-01

In this research works, four-layered aluminium-aluminium oxide (Al-Al2O3) graded composite materials were fabricated using powder metallurgy (PM) method. In processing, metal-ceramic graded composite materials of 0%, 10%, 20% and 30% weight percentage of ceramic concentration were prepared under 30 ton compaction load using a cylindrical die-punch set made of steel. After that, two-step pressureless sintering was carried out at sintering temperature and time 600°C and 3 hours respectively. It was observed that the sintered cylindrical specimens of 30 mm diameter were prepared successfully. The graded composite specimens were analysed and the properties such as density, microstructure and hardness were measured. It was found that after sintering process, the diameter of the graded cylindrical structure was decreased. Using both Archimedes method and rule of mixture (ROM), he density of structure was measured. The obtained results revealed that the microvickers hardness was increased as the ceramic component increases in the graded layer. Moreover, it was observed that the interface of the graded structure is clearly distinguished within the multilayer stack and the ceramic particles are almost uniformly distributed in the Al matrix.

Development of an on-line electrochemical analyser for trace level aluminium

International Nuclear Information System (INIS)

Chow, Christopher W.K.; Thomas, Shaun D.; Davey, David E.; Mulcahy, Dennis E.; Drikas, Mary

2003-01-01

An in-house designed computerised flow injection (FI) system for low-level aluminium analysis is examined. A simple, low cost electrochemical detection system has been implemented with computerised control and data acquisition system. The system consists of a commercial electrochemical analyser, FI components (manifold, pumps and valves) and an in-house designed control system to perform automated analysis. This system was developed to study aluminium speciation in water, particularly for drinking water. The analytical technique was based upon the complexation reaction between aluminium and a ligand--DASA (1,2-dihydroxy-anthraquinone-3-sulphonic acid). 'Labile' and total aluminium concentrations, Al labile and Al total , respectively, were determined by measuring the sample before and after UV irradiation by amperometry at +0.6 V. The limit of detection for this technique was 10 μg/l (0.37 μM) and the linear calibration range was up to 1.6 mg/l (60 μM) with r 2 value of 0.999. The Al labile /Al total ratios of the water treated by 40, 80 and 100 mg/l of alum using a laboratory scale pilot plant to simulate conventional drinking water treatment processes were found to be 0.4, 0.5 and 0.8, respectively. These results indicated that when higher alum dose was employed, the residual aluminium was present mostly as the 'labile' species. Whereas, if the treatment process was not running at its optimum condition (underdosing), a large portion of aluminium was present as natural organic matter (NOM) - aluminium complexes in the treated water. The system offers a practical and effective means of providing extended knowledge of residual aluminium in drinking water

Aluminium Matrix Composites Reinforced with Co-continuous Interlaced Phases Aluminium-alumina Needles

Directory of Open Access Journals (Sweden)

Elvio de Napole Gregolin

2002-09-01

Full Text Available An Al-5SiO2 (5 wt% of SiO2 aluminium matrix fiber composite was produced where the reinforcement consists of fossil silica fibers needles. After being heat-treated at 600 °C, the original fiber morphology was retained but its microstructure changed from solid silica to an interconnected (Al-Si/Al2O3 interlaced structure named co-continuous composite. A technique of powder metallurgy, using commercial aluminium powder and the silica fibers as starting materials, followed by hot extrusion, was used to produce the composite. The co-continuous microstructure was obtained partially or totally on the fibers as a result of the reaction, which occurs during the heat treatment, first by solid diffusion and finally by the liquid Al-Si in local equilibrium, formed with the silicon released by reaction. The internal structure of the fibers was characterized using field emission electron microscope (FEG-SEM and optical microscopy on polished and fractured samples.

Dust grains from the heart of supernovae

Science.gov (United States)

Bocchio, M.; Marassi, S.; Schneider, R.; Bianchi, S.; Limongi, M.; Chieffi, A.

2016-03-01

Dust grains are classically thought to form in the winds of asymptotic giant branch (AGB) stars. However, there is increasing evidence today for dust formation in supernovae (SNe). To establish the relative importance of these two classes of stellar sources of dust, it is important to know the fraction of freshly formed dust in SN ejecta that is able to survive the passage of the reverse shock and be injected in the interstellar medium. With this aim, we have developed a new code, GRASH_Rev, that allows following the dynamics of dust grains in the shocked SN ejecta and computing the time evolution of the mass, composition, and size distribution of the grains. We considered four well-studied SNe in the Milky Way and Large Magellanic Cloud: SN 1987A, CasA, the Crab nebula, and N49. These sources have been observed with both Spitzer and Herschel, and the multiwavelength data allow a better assessment the mass of warm and cold dust associated with the ejecta. For each SN, we first identified the best explosion model, using the mass and metallicity of the progenitor star, the mass of 56Ni, the explosion energy, and the circumstellar medium density inferred from the data. We then ran a recently developed dust formation model to compute the properties of freshly formed dust. Starting from these input models, GRASH_Rev self-consistently follows the dynamics of the grains, considering the effects of the forward and reverse shock, and allows predicting the time evolution of the dust mass, composition, and size distribution in the shocked and unshocked regions of the ejecta. All the simulated models aagree well with observations. Our study suggests that SN 1987A is too young for the reverse shock to have affected the dust mass. Hence the observed dust mass of 0.7-0.9 M⊙ in this source can be safely considered as indicative of the mass of freshly formed dust in SN ejecta. Conversely, in the other three SNe, the reverse shock has already destroyed between 10-40% of the

Characterising dust in JET with the new ITER-like wall

International Nuclear Information System (INIS)

Flanagan, J C; Matthews, G F; Widdowson, A; Arnoux, G; Harting, D; Cackett, A; Sertoli, M; Sieglin, B; Marsen, S; Bacharis, M; De Vries, P C; Coffey, I H; Brezinsek, S; Coenen, J W; Craciunescu, T; Murari, A; Hodille, E

2015-01-01

Recent studies dedicated to the characterisation of in-vessel dust in JET with the new ITER-like wall (ILW) show that dust levels are orders of magnitude lower compared with the latter stages of the carbon-wall (CW) period and are decreasing with operational time. Less than 1 g of dust was recovered in a recent inspection, compared with more than 200 g of material recovered at the end of the JET-CW life. Recent inspection of the ILW shows low rates of re-deposition with only small areas of damage of a type likely to create particulate matter. Quantifiers from laser scattering techniques also indicate an order of magnitude reduction in dust relative to the JET-CW and show that the amount of dust mobilized after a disruption is proportional to the dynamic vessel forces. It is not possible to infer what fraction of dust (if any) might be created by disruptions. However, disruption mitigation is found to reduce the amount of dust seen after moderate disruptions by a factor of 4. Analysis of the transient impurity events (TIEs) associated with dust show that tungsten dominates. A significant contribution to TIEs is also seen from iron, nickel and chromium (probably from steel and Inconel components). The incidence of severe negative effects on operations from TIEs is found to be relatively rare, with <1% of ILW disruptions linked to TIEs. The evolution of the TIE rate closely follows changes in the laser scattering dust quantifiers; both trend downwards in time but peak during periods of higher disruption rate (thought to be primarily driven by the mobilization of existing dust). (paper)

Generation of urban road dust from anti-skid and asphalt concrete aggregates.

Science.gov (United States)

Tervahattu, Heikki; Kupiainen, Kaarle J; Räisänen, Mika; Mäkelä, Timo; Hillamo, Risto

2006-04-30

Road dust forms an important component of airborne particulate matter in urban areas. In many winter cities the use of anti-skid aggregates and studded tires enhance the generation of mineral particles. The abrasion particles dominate the PM10 during springtime when the material deposited in snow is resuspended. This paper summarizes the results from three test series performed in a test facility to assess the factors that affect the generation of abrasion components of road dust. Concentrations, mass size distribution and composition of the particles were studied. Over 90% of the particles were aluminosilicates from either anti-skid or asphalt concrete aggregates. Mineral particles were observed mainly in the PM10 fraction, the fine fraction being 12% and submicron size being 6% of PM10 mass. The PM10 concentrations increased as a function of the amount of anti-skid aggregate dispersed. The use of anti-skid aggregate increased substantially the amount of PM10 originated from the asphalt concrete. It was concluded that anti-skid aggregate grains contribute to pavement wear. The particle size distribution of the anti-skid aggregates had great impact on PM10 emissions which were additionally enhanced by studded tires, modal composition, and texture of anti-skid aggregates. The results emphasize the interaction of tires, anti-skid aggregate, and asphalt concrete pavement in the production of dust emissions. They all must be taken into account when measures to reduce road dust are considered. The winter maintenance and springtime cleaning must be performed properly with methods which are efficient in reducing PM10 dust.

Trace aluminium determination and sampling problems of archeological bone employing destructive neutron activation analysis

International Nuclear Information System (INIS)

Blotcky, A.J.; Rack, E.P.; Recker, R.R.; Leffler, J.A.; Teitelbaum, S.

1978-01-01

A destructive neutron activation analysis procedure was developed for determining trace aluminium content in bone. The method is based on a carefully planned sample preparation, irradiation at a neutron flux for 3.1x10 11 nxcm -2 xs -1 for 5 minutes, and chemical separation based on ion exchange. It was found that bone samples soaked in aluminium containing soil gave highly elevated aluminium values as a result of the aluminium adsorption into the bone matrix. The maximum aluminium content values for prehistoric bones are larger than those of modern bones and comparable to aluminium levels present in bone from renal patients. (T.G.)

Fire exposed aluminium structures

NARCIS (Netherlands)

Maljaars, J.; Fellinger, J.E.J.; Soetens, F.

2005-01-01

Material properties and mechanical response models for fire design of steel structures are based on extensive research and experience. Contrarily, the behaviour of aluminium load bearing structures exposed to fire is relatively unexplored. This article gives an overview of physical and mechanical

Dust in the small Magellanic Cloud. 2: Dust models from interstellar polarization and extinction data

Science.gov (United States)

Rodrigues, C. V.; Magalhaes, A. M.; Coyne, G. V.

1995-01-01

We study the dust in the Small Magellanic Cloud using our polarization and extinction data (Paper 1) and existing dust models. The data suggest that the monotonic SMC extinction curve is related to values of lambda(sub max), the wavelength of maximum polarization, which are on the average smaller than the mean for the Galaxy. On the other hand, AZV 456, a star with an extinction similar to that for the Galaxy, shows a value of lambda(sub max) similar to the mean for the Galaxy. We discuss simultaneous dust model fits to extinction and polarization. Fits to the wavelength dependent polarization data are possible for stars with small lambda(sub max). In general, they imply dust size distributions which are narrower and have smaller mean sizes compared to typical size distributions for the Galaxy. However, stars with lambda(sub max) close to the Galactic norm, which also have a narrower polarization curve, cannot be fit adequately. This holds true for all of the dust models considered. The best fits to the extinction curves are obtained with a power law size distribution by assuming that the cylindrical and spherical silicate grains have a volume distribution which is continuous from the smaller spheres to the larger cylinders. The size distribution for the cylinders is taken from the fit to the polarization. The 'typical', monotonic SMC extinction curve can be fit well with graphite and silicate grains if a small fraction of the SMC carbon is locked up in the grain. However, amorphous carbon and silicate grains also fit the data well. AZV456, which has an extinction curve similar to that for the Galaxy, has a UV bump which is too blue to be fit by spherical graphite grains.

Manufacturing and Machining Challenges of Hybrid Aluminium Metal Matix Composites

Science.gov (United States)

Baburaja, Kammuluri; Sainadh Teja, S.; Karthik Sri, D.; Kuldeep, J.; Gowtham, V.

2017-08-01

Manufacturing which involves material removal processes or material addition processes or material transformation processes. One or all the processes to obtain the final desired properties for a material with desired shape which meets the required precision and accuracy values for the expected service life of a material in working conditions. Researchers found the utility of aluminium to be the second largest after steel. Aluminium and its metal matrix composite possess wide applications in various applications in aerospace industry, automobile industry, Constructions and even in kitchen utensils. Hybrid Al-MMCconsist of two different materials, and one will be from organic origin along with the base material. In this paper an attempt is made to bring out the importance of utilization of aluminium and the challenges concerned in manufacturing and machining of hybrid aluminium MMC.

High Temperature Strength of Oxide Dispersion Strengthened Aluminium

DEFF Research Database (Denmark)

Clauer, A.H.; Hansen, Niels

1984-01-01

constant (except for the material with the lowest oxide content). The high temperature values of the modulus-corrected yield stresses are approximately two-thirds of the low temperature value. During high temperature creep, there is a definite indication of a threshold stress. This threshold stress......The tensile flow stress of coarse-grained dispersion strengthened Al-Al2O3 materials were measured as a function of temperature (77–873 K) and volume fraction (0.19-0.92 vol.%) of aluminium oxide. For the same material, the creep strength was determined as a function of temperature in the range 573......–873 K. The modulus-corrected yield stress (0.01 offset) is found to be temperature independent at low temperature (195–472 K). Between 473 and 573 K, the yield stress starts to decrease with increasing temperature. At high temperatures (573–873 K), the modulus-corrected yield stress is approximately...

Electrical connection for aluminium conductors in automotive applications : Prestudy of available solutions for electrical connection methods of aluminium cables

OpenAIRE

Hamedi, Emilia

2017-01-01

Due to increasing weight of electrical component and wiring harnesses in a vehicle contrary to the demand of light constructed vehicles as well as the constantly increasing and fluctuating price of copper compared to aluminium’s stable and far lower price, the use of aluminium conductors as an alternative have been promoted.  This thesis work lay theoretical research of the available methods used for electrical connection of aluminium conductors in order to increase the knowledge about the av...

Ductile damage in aluminium alloy thin sheets: Correlation between micro-tomography observations and mechanical modeling

International Nuclear Information System (INIS)

Thuillier, S.; Maire, E.; Brunet, M.

2012-01-01

This work deals with the characterization of ductile damage in an aluminium alloy AA6016-T4 by X-ray micro-tomography, as a function of anisotropy and triaxiality. Interrupted tensile tests on notched samples with three different geometries were performed and the void volume fraction was measured for different strain values, up to rupture. It was shown that void volume fraction evolution with the strain is rather similar at 0° and 90° to RD but at 45° to RD it shows a more rapid evolution. Moreover, for the same strain level, a higher void volume fraction was recorded for a higher triaxiality ratio. Whatever the orientation and the stress triaxiality ratio, void volume fraction values range from 5×10 −4 up to 0.04. A numerical model based on Gurson–Tvergaard–Needleman constitutive equations was used to simulate the different tests. Hardening of the material was identified from macroscopic tensile test nucleation material parameters were identified by a direct method from void volume fraction evolution. It can be seen that the influence of triaxiality on void volume fraction is underestimated, though void growth is nicely predicted for the highest triaxiality ratio, for strains below 0.5. The load level was correctly predicted, except for high strain, where coalescence seems necessary to be taken into account.

Study on an intense dust storm over Greece

Science.gov (United States)

Kaskaoutis, D. G.; Kambezidis, H. D.; Nastos, P. T.; Kosmopoulos, P. G.

Springtime constitutes the most favorable period for Sahara dust outbreaks and transport over Eastern Mediterranean. This study investigates the aerosol properties during April 2005 using remote-sensing and ground-based measurements. Three dust events with high aerosol optical depth (AOD) values have been observed during the measuring period, with duration of two days, i.e. 11-12, 16-17 and 25-26 April 2005. In this paper we mainly focus on the intense dust event of 16-17 April 2005, when a thick dust layer transported from Libya affected the whole Greek territory. Very high AOD values obtained from Aqua-MODIS sensor were observed over Greece (mean 2.42 ± 1.25) on 17 April, while the respective mean April value was 0.31 ± 0.09. The AOD at 550 nm (AOD 550) values over Crete were even larger, reaching ˜4.0. As a consequence, the PM 10 concentrations over Athens dramatically increased reaching up to 200 μg m -3. On the other hand, the fine-mode fraction values obtained from Terra-MODIS showed a substantial decrease in the whole Greek area on 17 April with values below 0.2 in the Southern regions. The intense dust layer showed a complex behavior concerning its spatial and temporal evolution and allowed us to study the changes in the optical properties of the desert dust particles along their transport routes due to the mixing processes with other aerosol types. The results from different measurements (ground-based and remote-sensing) did not contradict each other and, therefore, are adequate for monitoring of dust load over the Eastern Mediterranean.

Measurement of oxide-layer thickness of internal granules in high-purity aluminium

International Nuclear Information System (INIS)

Takacs, S.; Ditroi, F.; Mahunka, I.

1989-01-01

Charged-particle activation analysis was used for the determination of bulk oxygen concentration in aluminium. High-purity aluminium samples and mixtures containing different amounts of alumina were irradiated by 13 MeV 3 He particles. The aim of the investigation was to determine the oxide-layer thickness on the surface of internal aluminium granules. The measurement was carried out by determining the bulk oxygen concentration in the samples, and calculating the oxide-layer thickness, by using model conditions about the microstructure of the aluminium samples. (author) 5 refs

The varied functions of aluminium-activated malate transporters-much more than aluminium resistance.

Science.gov (United States)

Palmer, Antony J; Baker, Alison; Muench, Stephen P

2016-06-15

The ALMT (aluminium-activated malate transporter) family comprises a functionally diverse but structurally similar group of ion channels. They are found ubiquitously in plant species, expressed throughout different tissues, and located in either the plasma membrane or tonoplast. The first family member identified was TaALMT1, discovered in wheat root tips, which was found to be involved in aluminium resistance by means of malate exudation into the soil. However, since this discovery other family members have been shown to have many other functions such as roles in stomatal opening, general anionic homoeostasis, and in economically valuable traits such as fruit flavour. Recent evidence has also shown that ALMT proteins can act as key molecular actors in GABA (γ-aminobutyric acid) signalling, the first evidence that GABA can act as a signal transducer in plants. © 2016 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Corrosion of research reactor aluminium clad spent fuel in water

International Nuclear Information System (INIS)

2003-01-01

This report describes research performed in ten laboratories within the framework of the IAEA Co-ordinated Research Project on Corrosion of Research Reactor Aluminium Clad Spent Fuel in Water. The project consisted of exposure of standard racks of corrosion coupons in the spent fuel pools of the participating research reactor laboratories and the evaluation of the coupons after predetermined exposure times, along with periodic monitoring of the storage water. A group of experts in the field contributed a state of the art review and provided technical supervision of the project. Localized corrosion mechanisms are notoriously difficult to understand, and it was clear from the outset that obtaining consistency in the results and their interpretation from laboratory to laboratory would depend on the development of an excellent set of experimental protocols. These experimental protocols are described in the report together with guidelines for the maintenance of optimum water chemistry to minimize the corrosion of aluminium clad research reactor fuel in wet storage. A large database on corrosion of aluminium clad materials has been generated from the CRP and the SRS corrosion surveillance programme. An evaluation of these data indicates that the most important factors contributing to the corrosion of the aluminium are: (1) High water conductivity (100-200 μS/cm); (2) Aggressive impurity ion concentrations (Cl - ); (3) Deposition of cathodic particles on aluminium (Fe, etc.); (4) Sludge (containing Fe, Cl - and other ions in concentrations greater than ten times the concentrations in the water); (5) Galvanic couples between dissimilar metals (stainless steel-aluminium, aluminium-uranium, etc); (6) Scratches and imperfections (in protective oxide coating on cladding); (7) Poor water circulation. These factors operating both independently and synergistically may cause corrosion of the aluminium. The single most important key to preventing corrosion is maintaining good

Effect of exposure to an Asian dust storm on fractional exhaled nitric oxide in adult asthma patients in Western Japan.

Science.gov (United States)

Watanabe, Masanari; Kurai, Jun; Sano, Hiroyuki; Shimizu, Eiji

2015-01-01

Epidemiological investigations indicate that an Asian dust storm (ADS) can aggravate respiratory disorders. However, the effects of ADS on airway inflammation remain unclear. The aim of this study was to investigate the association of exposure to ADS with airway inflammation. The subjects were 33 adult patients with asthma who measured daily peak flow expiratory (PEF) from March to May 2012. Fractional exhaled nitric oxide (FeNO) was measured before and after ADS. The FeNO values were 13.8±13.7 ppb before the ADS and 20.3±19.0 ppb after the ADS, with no significant difference. There was also no significant association of PEF with ADS exposure. However, the increase of FeNO after ADS exposure was proportional to the decrease of PEF (R=-0.78, P<0.0001). These results suggest that airway inflammation aggravated by ADS exposure may induce a decrease in pulmonary function in some adult patients with asthma.

THE ROLE OF DUST IN THE EARLY UNIVERSE. I. PROTOGALAXY EVOLUTION

International Nuclear Information System (INIS)

Yamasawa, Daisuke; Habe, Asao; Kozasa, Takashi; Nozawa, Takaya; Nomoto, Ken'ichi; Hirashita, Hiroyuki; Umeda, Hideyuki

2011-01-01

We develop one-zone galaxy formation models in the early universe, taking into account dust formation and evolution by supernova (SN) explosions. We focus on the time evolution of dust size distribution, because H 2 formation on the dust surface plays a critical role in the star formation process in the early universe. In the model, we assume that star formation rate (SFR) is proportional to the total amount of H 2 . We consistently treat (1) the formation and size evolution of dust, (2) the chemical reaction networks including H 2 formation both on the surface of dust and in gas phase, and (3) the SFR in the model. First, we find that, because of dust destruction due to both reverse and forward shocks driven by SNe, H 2 formation is more suppressed than in situations without such dust destruction. At the galaxy age of ∼0.8 Gyr, for galaxy models with virial mass M vir = 10 9 M sun and formation redshift z vir = 10, the molecular fraction is 2.5 orders of magnitude less in the model with dust destruction by both shocks than that in the model without dust destruction. Second, we show that the H 2 formation rate strongly depends on the interstellar medium (ISM) density around SN progenitors. The SFR in higher ISM density is lower, since dust destruction by reverse shocks is more effective in higher ISM density. We conclude that not only the amount but also the size distribution of dust related to star formation activity strongly affects the evolution of galaxies in the early universe.

Electrotransport of hydrogen in aluminium at 20 and 800 deg C

International Nuclear Information System (INIS)

Byalik, O.M.; Volkotrub, N.P.; Pinchuk, V.M.; Golub, L.V.; Degtyarenko, G.E.; Ivanchuk, D.F.

1982-01-01

Electrotransport of hydrogen in the field of crystal lattice of aluminium is investigated at the special installation using the method of measurement of electric resistivity. Quantum-mechanical calculation of H + and H - ions interaction with aluminium atoms is made to clarify the mechanizm of electrotransport. It is shown, that probability of the H + and H - ions permeation in the field of aluminium crystal lattice can be judged by the ratio of δE 1 (the lattice potential barrier) and δ 2 (the local energy minium in the case of atom arrangement in the lattice plane). The value of potentials of hydrogen ions interaction with aluminium lattice is obtained in the result os solution of the Schroedinger equation

AE Monitoring of Diamond Turned Rapidly Soldified Aluminium 443

International Nuclear Information System (INIS)

Onwuka, G; Abou-El-Hossein, K; Mkoko, Z

2017-01-01

The fast replacement of conventional aluminium with rapidly solidified aluminium alloys has become a noticeable trend in the current manufacturing industries involved in the production of optics and optical molding inserts. This is as a result of the improved performance and durability of rapidly solidified aluminium alloys when compared to conventional aluminium. Melt spinning process is vital for manufacturing rapidly solidified aluminium alloys like RSA 905, RSA 6061 and RSA 443 which are common in the industries today. RSA 443 is a newly developed alloy with few research findings and huge research potential. There is no available literature focused on monitoring the machining of RSA 443 alloys. In this research, Acoustic Emission sensing technique was applied to monitor the single point diamond turning of RSA 443 on an ultrahigh precision lathe machine. The machining process was carried out after careful selection of feed, speed and depths of cut. The monitoring process was achieved with a high sampling data acquisition system using different tools while concurrent measurement of the surface roughness and tool wear were initiated after covering a total feed distance of 13km. An increasing trend of raw AE spikes and peak to peak signal were observed with an increase in the surface roughness and tool wear values. Hence, acoustic emission sensing technique proves to be an effective monitoring method for the machining of RSA 443 alloy. (paper)

Sol gel synthesis for preparation of yttrium aluminium garnet

NARCIS (Netherlands)

Vrolijk, J.W.G.A.; Willems, J.W.M.M.; Metselaar, R.; With, de G.; Terpstra, R.A.; Metselaar, R.

1989-01-01

Sol-gel—synthesis for preparation of pure yttrium aluminium garnet powder with small grain size is subject of this ongoing study. Starting materials were sulfates and chlorides of yttrium and aluminium. To obtain pure YAG (Y3A1SO1Z) pH during hydrolysis as well as temperature during calcination and

Spectroscopic Measurements of the Far-Ultraviolet Dust Attenuation Curve at z ˜ 3

Science.gov (United States)

Reddy, Naveen A.; Steidel, Charles C.; Pettini, Max; Bogosavljević, Milan

2016-09-01

We present the first spectroscopic measurements of the shape of the far-ultraviolet (far-UV; λ =950{--}1500 Å) dust attenuation curve at high redshift (z˜ 3). Our analysis employs rest-frame UV spectra of 933 galaxies at z˜ 3, 121 of which have very deep spectroscopic observations (≳ 7 hr) at λ =850{--}1300 \\mathring{{A}} , with the Low Resolution Imaging Spectrograph on the Keck Telescope. By using an iterative approach in which we calculate the ratios of composite spectra in different bins of continuum color excess, E(B-V), we derive a dust curve that implies a lower attenuation in the far-UV for a given E(B-V) than those obtained with standard attenuation curves. We demonstrate that the UV composite spectra of z˜ 3 galaxies can be modeled well by assuming our new attenuation curve, a high covering fraction of H I, and absorption from the Lyman-Werner bands of {{{H}}}2 with a small (≲ 20 % ) covering fraction. The low covering fraction of {{{H}}}2 relative to that of the {{H}} {{I}} and dust suggests that most of the dust in the ISM of typical galaxies at z˜ 3 is unrelated to the catalysis of {{{H}}}2, and is associated with other phases of the ISM (I.e., the ionized and neutral gas). The far-UV dust curve implies a factor of ≈ 2 lower dust attenuation of Lyman continuum (ionizing) photons relative to those inferred from the most commonly assumed attenuation curves for L* galaxies at z˜ 3. Our results may be utilized to assess the degree to which ionizing photons are attenuated in H II regions or, more generally, in the ionized or low column density (N({{H}} {{I}})≲ {10}17.2 cm-2) neutral ISM of high-redshift galaxies. Based on data obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA, and was made possible by the generous financial support of the W.M. Keck Foundation.

Defect generation during solidification of aluminium foams

International Nuclear Information System (INIS)

Mukherjee, M.; Garcia-Moreno, F.; Banhart, J.

2010-01-01

The reason for the frequent occurrence of cell wall defects in metal foams was investigated. Aluminium foams often expand during solidification, a process which is referred as solidification expansion (SE). The effect of SE on the structure of aluminium foams was studied in situ by X-ray radioscopy and ex situ by X-ray tomography. A direct correlation between the magnitude of SE and the number of cell wall ruptures during SE and finally the number of defects in the solidified foams was found.

Aluminium, extractable from soil samples by the acid ammonium acetate soil-testing method

Directory of Open Access Journals (Sweden)

Osmo Mäkitie

1968-05-01

Full Text Available The extractant, 0.5 M acetic acid –0.5 M ammonium acetate at pH 4.65, which is used in soil-testing, extracts relatively high amounts of aluminium from acid soils. The mean values of acetate-extractable aluminium at pH 4.65, 1.75 meq Al/100 g of soil, and of exchangeable aluminium (M KCI extraction, 0.41 meq Al were obtained from a material of 30 samples of acid soils (Table 2. Several other acetic acid ammonium acetate extractants, from M acetic acid to M ammonium acetate solution were also used for studying the extractability of soil aluminium. The soil-testing extractant can be used for the estimation of the soluble amounts of aluminium in acid soils, however, further studies are needed for a better interpretation of the ammonium acetate extractable (at pH 4.65 aluminium in our soils.

Real-time mass measurement of dust particles deposited on vessel wall in a divertor simulator using quartz crystal microbalances

International Nuclear Information System (INIS)

Tateishi, Mizuki; Koga, Kazunori; Katayama, Ryu; Yamashita, Daisuke; Kamataki, Kunihiro; Seo, Hyunwoong; Itagaki, Naho; Shiratani, Masaharu; Ashikawa, Naoko; Masuzaki, Suguru; Nishimura, Kiyohiko; Sagara, Akio

2015-01-01

We are developing a dust monitoring method using quartz crystal microbalances (QCMs) equipped with a dust eliminating filter. Here we report a dust eliminating ratio of the filter and first measurement results of the QCMs in a divertor simulator. The volume of spherical dust in unit area on the filter and QCM under the filter were 2.09 × 10 −9 and 1.22 × 10 −10 m 3 m −2 , respectively. Thus, the dust eliminating ratio of the filter is 94.2%. The QCM without the filter gives deposition rate due to radicals and dust particles, whereas the QCM with the filter gives deposition rate predominantly due to radicals. From the results, we deduce information of mass fraction of dust particles in deposits

Factors affecting the aluminium content of human femoral head and neck.

Science.gov (United States)

Zioła-Frankowska, Anetta; Dąbrowski, Mikołaj; Kubaszewski, Łukasz; Rogala, Piotr; Frankowski, Marcin

2015-11-01

Tissues for the study were obtained intraoperatively during hip replacement procedures from 96 patients. In all the cases, the indication for this treatment was primary or secondary degenerative changes in the hip joint. The subject of the study was the head and neck of the femur, resected in situ. Aluminium concentrations measured in femoral head and neck samples from patients aged between 25 and 91 were varied. Statistical methods were applied to determine the variations in relation to the parameters from the background survey. Significant differences in the aluminium content of femoral head samples were observed between patients under and over 60 years of age. Based on the results, it was confirmed that the aluminium accumulates in bones over a lifetime. The study showed that the content of aluminium in the head and neck of the femur depends on the factors such as: type of medicines taken, contact with chemicals at work, differences in body anatomy and sex. The study on the levels of aluminium in bones and the factors affecting its concentration is a valuable source of information for further research on the role of aluminium in bone diseases. Based on the investigations, it was found that the GF-AAS technique is the best analytical tool for routine analysis of aluminium in complex matrix samples. The use of femoral heads in the investigations was approved by the Bioethics Committee of the University of Medical Sciences in Poznań (Poland). Copyright © 2015 Elsevier Inc. All rights reserved.

Crystal structure and phase composition of aluminium thin films with holmium additions

International Nuclear Information System (INIS)

Koleshko, V.M.; Belitskij, V.F.; Obukhov, V.E.; Rumak, N.V.; Urban, T.P.

1984-01-01

The effect of holmium additions on the crystal structure and phase composition of thin aluminium films has been studied. A regularity in grain size changes in aluminium thin films versus the holmium content in them is established. The holmium introduction is shown to result in the appearance of axial texture in the aluminium films, the texture axis being determined by the quantity of the addition. During heat treatment of the aluminium films, containing holmium additions, in the range of low ( approximately 100-200 deg C) annealing temperatures holmium monohydroxide is formed, and at annealing temperatures 300 deg C 0 3 is formed

Chemical characterization of atmospheric dust from a weekly time series in the north Red Sea between 2006 and 2010

Science.gov (United States)

Torfstein, Adi; Teutsch, Nadya; Tirosh, Ofir; Shaked, Yeala; Rivlin, Tanya; Zipori, Assaf; Stein, Mordechai; Lazar, Boaz; Erel, Yigal

2017-08-01

Atmospheric dust loads and chemical compositions serve as a key link between global climate patterns and marine biogeochemical cycles. The primary source of atmospheric dust in the world today is the Sahara-Arabian desert belt. Although this source was also active during the Quaternary, the interpretation of paleo-dust records and their effects on marine ecosystems is complicated by the scarcely reported atmospheric load patterns of bioavailable phases (i.e., water and acid leachable phases) and present-day contamination of anthropogenic components. This study reports a multi-annual time series of atmospheric dust loads (2006-2016) and their chemical compositions (2006-2010) collected in the north Gulf of Aqaba (north Red Sea) at a weekly to bi-weekly resolution. Major and trace element abundances in each sample are reported for three fractions: water-soluble salts, carbonates and oxides (weak acid leach), and Al-silicates. Dust loads vary seasonally from low values in late summer (∼20-30 μg m-3) to higher values in the fall, and highest values in late winter and early spring (∼150-250 μg m-3). Major and trace element abundances allow to distinguish between the sources and chemical compositions that dominate high and low dust loads in each season. The water leachable fraction (L0) is relatively enriched in Na, Ca, K and Mg, the acid-leachable fraction (L1) is enriched in Ca as well as Na, Al, Mg, Zn, Cd and Pb, and the silicate residue (L2) in Al and Fe. High dust loads occurring mainly during winter and spring months are characterized by low Mg/Ca (L1, L2), low K/Al and Na/Al (L1) and high Ca/Al (L1), high Mg/Al (L2) and relatively un-weathered (L2) contents. High dust load intervals during winter months are characterized by low passing air masses originating from the Sahara, while the ambient winter dust (low dust load) is associated with proximal source regions from the East Sahara and Arabian Peninsula. During late winter and spring months, high dust

The effects of aluminium and selenium supplementation on brain ...

African Journals Online (AJOL)

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

Can we detect Galactic spiral arms? 3D dust distribution in the Milky Way

Science.gov (United States)

Rezaei Kh., Sara; Bailer-Jones, Coryn A. L.; Fouesneau, Morgan; Hanson, Richard

2018-04-01

We present a model to map the 3D distribution of dust in the Milky Way. Although dust is just a tiny fraction of what comprises the Galaxy, it plays an important role in various processes. In recent years various maps of dust extinction have been produced, but we still lack a good knowledge of the dust distribution. Our presented approach leverages line-of-sight extinctions towards stars in the Galaxy at measured distances. Since extinction is proportional to the integral of the dust density towards a given star, it is possible to reconstruct the 3D distribution of dust by combining many lines-of-sight in a model accounting for the spatial correlation of the dust. Such a technique can be used to infer the most probable 3D distribution of dust in the Galaxy even in regions which have not been observed. This contribution provides one of the first maps which does not show the ``fingers of God'' effect. Furthermore, we show that expected high precision measurements of distances and extinctions offer the possibility of mapping the spiral arms in the Galaxy.

Evaluation of errors and limits of the 63-μm house-dust-fraction method, a surrogate to predict hidden moisture damage

Directory of Open Access Journals (Sweden)

Assadian Ojan

2009-10-01

Full Text Available Abstract Background The aim of this study is to analyze possible random and systematic measurement errors and to detect methodological limits of the previously established method. Findings To examine the distribution of random errors (repeatability standard deviation of the detection procedure, collective samples were taken from two uncontaminated rooms using a sampling vacuum cleaner, and 10 sub-samples each were examined with 3 parallel cultivation plates (DG18. In this two collective samples of new dust, the total counts of Aspergillus spp. varied moderately by 25 and 29% (both 9 cfu per plate. At an average of 28 cfu/plate, the total number varied only by 13%. For the evaluation of the influence of old dust, old and fresh dust samples were examined. In both cases with old dust, the old dust influenced the results indicating false positive results, where hidden moist was indicated but was not present. To quantify the influence of sand and sieving, 13 sites were sampled in parallel using the 63-μm- and total dust collection approaches. Sieving to 63-μm resulted in a more then 10-fold enrichment, due to the different quantity of inert sand in each total dust sample. Conclusion The major errors during the quantitative evaluation from house dust samples for mould fungi as reference values for assessment resulted from missing filtration, contamination with old dust and the massive influence of soil. If the assessment is guided by indicator genera, the percentage standard deviation lies in a moderate range.

Aluminium concentration versus the base cation to aluminium ratio as predictors for aluminium toxicity in Pinus sylvestris and Picea abies seedlings

NARCIS (Netherlands)

Schöll, van L.; Keltjens, W.G.; Hoffland, E.; Breemen, van N.

2004-01-01

Aluminium (Al) toxicity is considered an important factor in forest deterioration caused by soil acidification. A ratio of base cations (BC) to Al in the soil solution lower than 1 is widely used as an indicator for potentially adverse effects on tree health. In our view, the validity of the

Effect of microcrystallization on pitting corrosion of pure aluminium

International Nuclear Information System (INIS)

Meng Guozhe; Wei Liyan; Zhang Tao; Shao Yawei; Wang Fuhui; Dong Chaofang; Li Xiaogang

2009-01-01

A microcrystalline aluminium film with grain size of about 400 nm was prepared by magnetron sputtering technique. Its corrosion behaviour was investigated in NaCl containing acidic solution by means of potentiodynamic polarization curves and electrochemical noise (EN). The polarization results indicated that the corrosion potential of the sample shifted towards more positive direction, while its corrosion current density decreased compared with that of pure coarse-grain Al. The EN analysis based on stochastic model demonstrated that there existed two kinds of effect of microcrystallization on the pitting behaviour of pure aluminium: (1) the rate of pit initiation is accelerated, (2) the pit growth process was impeded. This leads to the enhancement of pitting resistance for the microcrystallized aluminium.

Three body abrasion of laser surface alloyed aluminium AA1200

CSIR Research Space (South Africa)

Mabhali, Luyolo AB

2012-06-01

Full Text Available Laser surface alloying of aluminium AA1200 was performed with a 4 kW Nd:YAG laser to improve the abrasion wear resistance. Aluminium surfaces reinforced with metal matrix composites and intermetallic phases were achieved. The phases present depended...

Neutron activation analysis of baths forming conversion layer on aluminium

International Nuclear Information System (INIS)

Szilagyi, Istvan; Maleczki, Emil; Bodizs, Denes

1988-01-01

Chromate layers were formed on the surface of aluminium using yellow and green chromating solutions. For the determination of the aluminium content neutron activation method was used. Nuclear effects disturbing the determination were eliminated by double irradiation technique. (author) 8 refs.; 4 figs

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

Science.gov (United States)

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

2014-01-01

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

Decomposition of oxidezed lead and aluminium thin films on molybdenum substrates

International Nuclear Information System (INIS)

Makarovskij, N.A.

1981-01-01

The decomposition of oxidized solid phase lead and aluminium thin films on molybdenum substrates in the process of diffusion annealing in the 5x10 -5 mm Hg vacuum at temperatures from 280 to 320 deg C and from 500 to 560 deg C, respectively, is investigated. The conclusion is made that failure of oxidized lead and aluminium thin film coatings is carried out by the mechanism of volumetric self-diffusion. Experimentally established values of activation energies of the process of lead (Qsub(Mo)sup(Pb)=29 kcal/mol) and aluminium (Qsub(Mo)sup(Al)=35 kcal/mol) film failure are close to corresponding activation energies of lead and aluminium volumetric self-diffusion, which agrees with the conclusions made [ru

Corrosion Inhibition of Aluminium in Acid Media By Citrullus Colocynthis Extract

Directory of Open Access Journals (Sweden)

Rajkiran Chauhan

2011-01-01

Full Text Available Inhibition of corrosion of aluminium in acid solution by methanol extract of Citrullus colocynthis plant has been studied using mass loss and thermometric measurements. It has been found that the plant extract act as a good corrosion inhibitor for aluminium in all concentrations of sulphuric and hydrochloric acid solution. The inhibition action depends on the concentration of acid and inhibitor. Results for mass loss and thermometric measurement indicate that inhibition efficiency increase with increasing inhibitor concentration. The inhibition action of the plant extract is discussed in view of Langmuir adsorption isotherm. It has been observed that the adsorption of the extract on aluminium surface is a spontaneous process. The plant extract provides a good protection to aluminium against corrosion.

Method of preparing an Al-Ti-B grain refiner for aluminium-comprising products, and a method of casting aluminium products

OpenAIRE

Brinkman, H.J.; Duszczyk, J.; Katgerman, L.

1999-01-01

The invention relates to a method of preparing an Al-Ti-B grain refiner for cast aluminium-comprising products. According to the invention the preparation is realized by mixing powders selected from the group comprising aluminium, titanium, boron, and alloys and intermetallic compounds thereof, compressing, heating in an inert environment until an exothermic reaction is initiated and cooling. It has been shown that when the grain refiner thus prepared is applied, the quality of cast products ...

DustEM: Dust extinction and emission modelling

Science.gov (United States)

Compiègne, M.; Verstraete, L.; Jones, A.; Bernard, J.-P.; Boulanger, F.; Flagey, N.; Le Bourlot, J.; Paradis, D.; Ysard, N.

2013-07-01

DustEM computes the extinction and the emission of interstellar dust grains heated by photons. It is written in Fortran 95 and is jointly developed by IAS and CESR. The dust emission is calculated in the optically thin limit (no radiative transfer) and the default spectral range is 40 to 108 nm. The code is designed so dust properties can easily be changed and mixed and to allow for the inclusion of new grain physics.

Elemental analysis of various biomass solid fractions in biorefineries by X-ray fluorescence spectrometry

DEFF Research Database (Denmark)

Le, Duy Michael; Sorensen, Hanne R.; Meyer, Anne S.

2017-01-01

, poplar) followed by enzymatic hydrolysis and fermentation. For all the different biomasses, the biorefinery process concentrated silicon, aluminium, and calcium in the solid fraction, while potassium and magnesium were solubilised in the process and removed from the solid fraction. Sodium concentrations....... Based on ultimate elemental analysis of all biomasses, the formula for biomass was C6H8.4O3.5, which was used for all types of samples (raw biomass, pretreated biomass, and lignin residue) and can be used in future XRF analysis of samples of similar process and biomass feedstock as those used...

An aluminium evaporation source for ion plating

International Nuclear Information System (INIS)

Walley, P.A.; Cross, K.B.

1977-01-01

Ion plating with aluminium is becoming increasingly accepted as a method of anti-corrosion surface passivation, the usual requirements being for a layer between 12 and 50 microns in thickness, (0.0005 to 0.002). The evaporation system described here offers a number of advantages over high power electron beam sources when used for aluminium ion plating. The source consists of a resistively heated, specially shaped, boron nitride-titanium diboride boat and a metering feed system. Its main features are small physical size, soft vacuum compatibility, low power consumption and metered evaporation output. (author)

Bioactive type glass-ceramics within incorporated aluminium

International Nuclear Information System (INIS)

Volzone, C.; Stabile, F.M.; Ortiga, J.

2012-01-01

Bioactive glass-ceramics are used as biomaterials for the reparation of bone tissue. They are prepared, generally, by bioglass of specific composition for each particular use. The aluminium addition in the formulation at very small quantities influences on the structural properties. Two glass-ceramics obtained by P 2 O 5 -Na 2 O-CaO-SiO 2 formulation within aluminium (0.5 % in Al 2 O 3 base) added through a reactive alumina and purified feldspar were analyzed. The results showed structural differences between both glass-ceramics. (author)

Efficiency of the deposition mode ice nucleation on mineral dust particles

Directory of Open Access Journals (Sweden)

O. Möhler

2006-01-01

Full Text Available The deposition mode ice nucleation efficiency of various dust aerosols was investigated at cirrus cloud temperatures between 196 and 223 K using the aerosol and cloud chamber facility AIDA (Aerosol Interaction and Dynamics in the Atmosphere. Arizona test dust (ATD as a reference material and two dust samples from the Takla Makan desert in Asia (AD1 and the Sahara (SD2 were used for the experiments at simulated cloud conditions. The dust particle sizes were almost lognormally distributed with mode diameters between 0.3 and 0.5 μm and geometric standard deviations between 1.6 and 1.9. Deposition ice nucleation was most efficient on ATD particles with ice-active particle fractions of about 0.6 and 0.8 at an ice saturation ratio SiSiSi. This indicates that deposition ice nucleation on mineral particles may not be treated in the same stochastic sense as homogeneous freezing. The suggested formulation of ice activation spectra may be used to calculate the formation rate of ice crystals in models, if the number concentration of dust particles is known. More experimental work is needed to quantify the variability of the ice activation spectra as function of the temperature and dust particle properties.

Assessment of heavy metal contamination of dust at some selected fuel filling stations in Accra

International Nuclear Information System (INIS)

Afrifa, C. G.

2011-07-01

Heavy metal contaminated dust particles of fuel filling stations can be re-suspended into the ambient air and serve as a source of atmospheric pollution since the fine particles are aerodynamic and have longer life time in ambient air. This can cause ill-health effect on the fuel attendants and residents within the neighbourhood especially infants and the aged who are more vulnerable. In spite of this, not much research has been done on heavy metal contamination of dust at fuel filling stations. In this study, 55 dust samples were collected from six fuel filling stations in the Ga-East district and Accra Metropolitan assembly, both in Accra, in order to assess the levels of contamination of heavy metals; their possible sources and the human health risk associated with them. The dust samples were divided into two parts with one part sieved into four fractions using metric mesh sizes 500 µm, 200µm, 100µm and 45 µm, and pulverised. Total concentrations of heavy metals (Si, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Br, Rb, Sr, Y, Zr and Pb) were determined in the dust samples using energy dispersive X-ray fluorescence analysis. The pollution indices; enrichment factors (EF), index of geoaccumulation (Igeo), contamination factor (CF) and pollution load index (PLI) were used to identify possible levels of pollution from anthropogenic sources. The possible sources of metals were also identified with principal component analysis. Noncancer effect of children and adults due to exposure to dust from these fuel filling stations were also estimated. For the three fuelling areas, the average concentrations of V, Cr, Ni and Cu exceeded the acceptable values in common soil in the <45 µm fraction. The average concentration of Zn however exceeded the acceptable value only at the mixed-fuel fuelling area whereas the average concentration of Pb was within the acceptable value for all three fuelling areas. The dust samples showed moderate to significant enrichments for V, Cu, Br

Aluminium-rich corner in Al-Cu-La system

International Nuclear Information System (INIS)

Yunusov, I.; Ganiev, I.N.

1990-01-01

Aluminium corner of Al-Cu-La system are investigated by means of microstructural and differential thermal analysis. Existence of LaCu 2 Al 10 and LaCu 0.5 Al 3.5 ternary compounds in the system is confirmed and it is shown, as well, both compounds are in two-phase equilibrium with aluminium solid solution and form with it and between each other eutectic type state diagrams. State diagrams for quasibinary sections are plotted

Elastic and plastic properties of iron-aluminium alloys. Special problems raised by the brittleness of alloys of high aluminium content

International Nuclear Information System (INIS)

Mouturat, P.

1966-06-01

The present study embodies the results obtained with iron-aluminium alloys whose composition runs from 0 to nearly 50 atoms per cent aluminium. Conditions of elaboration and transformation have been studied successively, as well as the Young's modulus and the flow stress; the last chapter embodies, a study of the Portevin-le-Chatelier effect in alloys of 40 atoms per cent of aluminium. I) The principal difficulty to clear up consisted in the intergranular brittleness of ordered alloys; this brittleness has been considerably reduced with appropriate conditions of elaboration and transformation. II) The studies upon the Young's modulus are in connection with iron-aluminium alloys; transformation temperatures are well shown up. The formation of covalent bonds on and after 25 atoms per cent show the highest values of the modulus. III) The analysis of variations of the flow stress according to the temperature show some connection with ordered structures, the existence of antiphase domains and the existence of sur-structure dislocations. IV) In the ordered Fe Al domain the kinetics of the Portevin-le-Chatelier effect could be explained by a mechanism of diffusion of vacancies. The role they play has been specified by the influence they exert upon the dislocations; this has led us to the inhomogeneous Rudman order; this inhomogeneous order could explain the shape of the traction curves. (author) [fr

Pulmonary function, respiratory symptoms, and dust exposures among workers engaged in early manufacturing processes of tea: a cohort study.

Science.gov (United States)

Shieh, Tzong-Shiun; Chung, Jui-Jung; Wang, Chung-Jing; Tsai, Perng-Jy; Kuo, Yau-Chang; Guo, How-Ran

2012-02-13

To evaluate pulmonary function and respiratory symptoms in workers engaged in the early manufacturing processes of tea and to identify the associated factors, we conducted a study in a tea production area in Taiwan. We recruited tea workers who engaged in the early manufacturing process in the Mountain Ali area in Taiwan and a comparison group of local office workers who were matched for age, gender, and smoking habits. We performed questionnaire interviews, pulmonary function tests, skin prick tests, and measurement of specific IgE for tea on the participants and assessed tea dust exposures in the tea factories. The 91 participating tea workers had higher prevalence of respiratory symptoms than the comparison group (32 participants). Among tea workers, ball-rolling workers had the highest prevalence of symptoms and the highest exposures of inhalable dusts. At baseline, tea workers had similar pulmonary functions as the comparison group, but compared to the other tea workers ball-rolling workers had a lower ratio of the 1-second forced expiratory volume to forced vital capacity (FEV1/FVC) and a lower maximal mid-expiratory flow rate expressed as% of the predicted value--MMF (%pred). A total of 58 tea workers participated in the on-site investigation and the cross-shift lung function measurements. We found ball-rolling yielded the highest inhalable dust level, panning yielded the highest respirable dust level, and withering yielded the lowest levels of both dusts. Ball-rolling also yielded the highest coarse fraction (defined as inhalable dusts minus respirable dusts), which represented exposures from nose to tracheobronchial tract. During the shift, we observed significant declines in pulmonary function, especially in ball-rolling workers. Multiple regressions showed that age, height, work tasks, coarse fraction, and number of months working in tea manufacturing each year were independent predictors of certain pulmonary function parameters in tea workers. Tea

Photodynamic effect of aluminium and zinc tetrasulfophthalocyanines on melanoma cancer cells

CSIR Research Space (South Africa)

Maduray, K

2010-06-01

Full Text Available Aluminium and zinc tetrasulfophthalocyanines were activated with a 672nm wavelength laser to investigate the photodynamic effects on melanoma cancer, dermal fibroblast and epidermal keratinocyte cells. Aluminium tetrasulfophthalocyanine was more...

Comparison of Powder Dusting and Cyanoacrylate Fuming Techniques in Retrieving Latent Fingerprint Exposed to Environment Conditions

International Nuclear Information System (INIS)

Mayalvanan, Y.; Sri Pawita Albakri Amir Hamzah; Chuan, L.L.; Muhamad Hilmi Baba; Amidon Anan

2014-01-01

Latent fingerprints are one of the best evidence to prove the presence of an individuals presence at the crime scene. There are many techniques available for a successful fingerprint lifting. Two of the most common ones are fingerprint powder dusting and cyanoacrylate fuming. This research aims to compare both techniques and determine which has a higher success rate in retrieving fingerprints exposed to local environmental conditions for three days. Fingerprint samples were collected from 18 subjects on glass, perspex and aluminium slides. These samples were then exposed to local environmental conditions for three days. The fingerprints were then developed using the aforementioned techniques. Based on the results, it can be safely said that, fuming results in clearer fingerprints and more minutiae can be found from the retrieved fingerprints even with exposure to less than optimum local conditions. This proves that fuming is a better fingerprint lifting method to resolve latent fingerprint compared to powder dusting. Surface on which the fingerprint is retrieved from influences the quality of clarity of a latent fingerprint. (author)

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

Science.gov (United States)

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

2013-11-01

Aluminium oxyhydroxide, Al(OH)3 is one of few compounds approved as an adjuvant in human vaccines. However, the mechanism behind its immune stimulating properties is still poorly understood. In vitro co-culture of an aluminium adjuvant and the human monocytic cell line THP-1 resulted in reduced cell proliferation. Inhibition occurred at concentrations of adjuvant several times lower than would be found at the injection site using a vaccine formulation containing an aluminium adjuvant. Based on evaluation of the mitochondrial membrane potential, THP-1 cells showed no mitochondrial rupture after co-culture with the aluminium adjuvant, instead an increase in mitochondrial activity was seen. The THP-1 cells are phagocytosing cells and after co-culture with the aluminium adjuvant the phagosomal pathway was obstructed. Primary or early phagosomes mature into phagolysosomes with an internal pH of 4.5 - 5 and carry a wide variety of hydrolysing enzymes. Co-culture with the aluminium adjuvant yielded a reduced level of acidic vesicles and cathepsin L activity, a proteolytic enzyme of the phagolysosomes, was almost completely inhibited. THP-1 cells are an appropriate in vitro model in order to investigate the mechanism behind the induction of a phagocytosing antigen presenting cell into an inflammatory cell by aluminium adjuvants. Much information will be gained by investigating the phagosomal pathway and what occurs inside the phagosomes and to elucidate the ultimate fate of phagocytosed aluminium particles. © 2013.

Numerical/experimental research on welded joints in aluminium truss girders

NARCIS (Netherlands)

van Hove, B.W.E.M.; Soetens, F.; Mazzolani, F.M.; Bellucci, F.; Faggiano, B.; Squillace, A.

2016-01-01

Welded joints in a 30 meter span aluminium truss girder were investigated numerically and experimentally. Since aluminium design rules for welded K-and N-joints in CHS truss girders were lacking the joints were checked using steel design rules. Calculations showed that the N-joints were governing