WorldWideScience

Sample records for aluminium plate oxidation

  1. Spark counting technique with an aluminium oxide film

    International Nuclear Information System (INIS)

    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/cm2. 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.)

  2. Thickness Evaluation of Aluminium Plate Using Pulsed Eddy Current Technique

    Science.gov (United States)

    Singh, Gurpartap; Bapat, Harsh Madhukar; Singh, Bhanu Pratap; Bandyopadhyay, Manojit; Puri, Rakesh Kumar; Badodkar, Deepak Narayanrao

    2013-10-01

    This paper describes a pulsed eddy current (PEC) based non-destructive testing system used for detection of thickness variation in aluminium plate. A giant magneto-resistive sensor has been used instead of pick up coil for detecting resultant magnetic field. The PEC response signals obtained from 1 to 5 mm thickness change in aluminium plate were investigated. Two time domain features, namely peak value and time to peak, of PEC response were used for extracting information about thickness variation in aluminium plate. The variation of peak value and time to peak with thickness was compared. A program was developed to display the thickness variation of the tested sample.

  3. Corrosion behaviour of aluminium plates in aqueous medium

    International Nuclear Information System (INIS)

    The process of corrosion concerning the aluminium 1050 plate was studied at room temperatures, 45 and 600C in deionized water, the same Argonauta Reactor Water. Beyond the temperature influence, it was verified the effect of chloride ion and oxygen. It ws found that the amount of oxyde formed at room temperatures is almost negligible; at 45 and 600C the samples were covered with bayerita, the quantity of oxide formed at 450C being higher than at 600C. It was observed that there will be risk of corrosion in the case of Reactor Water to undergo contamination with chloride ions. The results have shown that the material can be used since the medium don't be strongly oxidizing. At potentials higher than - 900M sup(V) ess (-280 m sup(V) sub(H)), the material will undergo pitting corrosion. (Author)

  4. Dispersion strengthening of aluminium-aluminium-oxide products

    DEFF Research Database (Denmark)

    Hansen, Niels

    1970-01-01

    temperature and at 400°C is in agreement with Orowan's theory. The increase in flow stress at room temperature for strain values below 3 per cent was related to the plastic strain by the equation σ-σoy=k1ε 1/2, where σoy is the initial flow stress and where k1 increases for increasing volume fraction......The true stress-true strain curves at room temperature and at 400°C were determined for various types of aluminium-aluminium-oxide products containing from 0.2 to 4.7 weight per cent of aluminium oxide. The effect of particles on the initial flow stress and the flow stress for 0.2% offset at room...

  5. Refractory oxides containing aluminium and barium

    OpenAIRE

    Davies T.J.; Biedermann M.; Q-G. Chen; Emblem H. G.; Al-Douri W. A.

    1998-01-01

    Oxides containing aluminium and barium, optionally with chromium, are refractory with several possible industrial uses. A gel precursor of an oxide having the formula BaO.n(Al2xCr2yO3), where 1aluminium salt or a solution of an aluminium salt and a chromium III salt, then forming a gel which was fired to obtain the desired oxide. Filaments may be drawn as the gel is forming or extr...

  6. Blast Loaded Aluminium Plates : Experiments and numerical simulations

    OpenAIRE

    Melby, Emil Arne; Eide, Hilde Olaug Stakvik

    2013-01-01

    Light and flexible protective constructions in aluminium could be subjected to a blast load. In this thesis the effect of blast loading on aluminium plates of the type 1050A ? H14 was studied through experiments and numerical simulations. The effect of fragmentation was idealized with predrilled holes. The thesis was written at the Structural Impact Laboratory (SIMLab) at NTNU in collaboration with the Norwegian Defence Estates Agency (NDEA).Tensile tests revealed a clearly anisotropic behavi...

  7. Oblique Impact of Projectile on Thin Aluminium Plates

    Directory of Open Access Journals (Sweden)

    W.U. Khan

    2003-04-01

    Full Text Available Experiments were performed, wherein cylindrical projectiles made of hardened steel were impacted on commercially available aluminium plates at different angles. Projectiles were of 12.8 mm diameter and plates were of 0.81 mm, 1.52mm and 1.91mm thicknesses. Based on the experimental results, an analytical model has been developed to predict the residual velocity of the projectile and the ballistic limit of the plate.

  8. Impact of Inert Metal Particles Flow on Aluminium Plate

    Institute of Scientific and Technical Information of China (English)

    WANG Zhongqi; LIU Yi; CHEN Yahong; BAI Chunhua

    2008-01-01

    Inert metal explosive, a new kind of explosive, is a mixture of high explosive and inert metal particle.When this kind of explosive is detonated, an inert metal particle flow will be formed by the explosive product driving.To determine the characteristics of the movement of the metal particle flow, a series of aluminium plates were designed to be the targets on which the metal particle flow impacted.The test result was presented and a numerical model was set up to analyze the impact of the high speed inert metal particles on aluminium plate.Based on the numerical analysis, the relationship between the characteristic of the mark on the target plate and the initial condition of the inert metal particles was proposed.From the analysis of the impact on target plates, more information about the movement of the metal particles could be reconstructed.

  9. Gating System Design for Casting thin Aluminium Alloy (Al-Si Plates

    Directory of Open Access Journals (Sweden)

    Victor ANJO

    2013-11-01

    Full Text Available The main problems caused by improper gating are entrained aluminium oxide films, cuts and washes, low casting yield and entrapped gas. This study describes the design of a gating system to produce thin Aluminium cast alloy plates of different sizes and thicknesses of 4mm, 6mm, 8mm, and 10mm using the non-pressurized gating with ratio of 1:4:4 and green sand moulding technique. The gating design was based on the laws of fluid mechanics and empirical rules of gating for non ferrous metals. The equipments used for this experiment includes; a coal fired crucible furnace and an X-Ray machine. Materials used include; silica sand, clay, wood, glue and Aluminium alloy scraps. The experimental procedure involved: the gating design calculations, construction of wooden pattern and gating; using the wooden pattern and gating to produce the mould cavities and gating; melting, melt treatment and pouring of melt in the sand mould to produce the casting. The plate castings after removal from mould were visually examined for surface defects and after fettling and cleaning X-Ray radiography was used to find the internal soundness of the castings. From the results obtained in the experiment, it was found that there were no internal defects and quality castings were produced.

  10. Oxidation effects during laser cladding of aluminium with SiC/Al powders

    NARCIS (Netherlands)

    Hegge, H.J.; Boetje, J.; Hosson, J.Th.M. De

    1990-01-01

    Aluminium substrates were covered with a layer of an Al-SiC powder mixture. The surface was scanned with a laser beam during which the surface was melted. The top layer of the laser tracks contained oxide plates apart from some large SiC particles. In the bottom layer a cellular network was found wi

  11. 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.

  12. Eu(III)-doped aluminium yttrium oxide

    International Nuclear Information System (INIS)

    In this work, we report the synthesis and the photoluminescence features of Eu(III)-doped yttrium-aluminium oxide obtained by non-hydrolytic sol-gel routes. After heating the powders above 600 deg C the XRD patterns show the presence of the Y4Al2O9 (YAM) and Y3Al5O12 (YAG) phases. At 800 and at 1500 deg C the PL spectra display the Eu(III) lines characteristic of the YAM monoclinic phase. The 5D0→7F2 transition is favored relatively to the 5D0→7F1 lines. However, at 1100 deg C the cubic YAG is the preferential phase and the 5D0→7F1 transition dominates the spectrum. The Eu(III) ions lie in a centro symmetrical site. The different solvents used in the sol-gel synthesis also change the relative proportion between these two phases. This is monitored analyzing the modifications in the relative intensity between the 5D0→7F2 and the 5D0→7F1 transitions. (author)

  13. Separation of 35S-sulfate on neutral aluminium oxide

    International Nuclear Information System (INIS)

    The results of 35S-sulfate chromatography on neutral aluminium oxide (γ-Al2O3) are presented. Possibility of quantitative adsorption of 35S-sulfate on Al2O3 from acidic or neutral potassium chloride solutions of high concentration is shown. Dynamic adsorption capacity of neutral aluminium oxide with respect to sulfate from weakly acidic potassium chloride solution equals near 10 μmol/ml of adsorbent. Optimal parameters for chromatographic isolation of 35S-sulfate without carrier from irradiated KCl target are determined. (author)

  14. Water defluoridation by aluminium oxide-manganese oxide composite material.

    Science.gov (United States)

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

    2014-08-01

    In this study, aluminium oxide-manganese oxide (AOMO) composite material was synthesized, characterized, and tested for fluoride removal in batch experiments. AOMO was prepared from manganese(II) chloride and aluminium hydroxide. The surface area of AOMO was found to be 30.7m2/g and its specific density was determined as 2.78 g/cm3. Detailed investigation of the adsorbent by inductively coupled plasma-optical emission spectrometry, inductively coupled plasma-mass spectrometry, and ion chromatography (for sulphate only) showed that it is composed of Al, Mn, SO4, and Na as major components and Fe, Si, Ca, and Mg as minor components. Thermogravimetric analysis was used to study the thermal behaviour of AOMO. X-ray diffraction analysis showed that the adsorbent is poorly crystalline. The point of zero charge was determined as 9.54. Batch experiments (by varying the proportion of MnO, adsorbent dose, contact time, initial F concentration, and raw water pH) showed that fluoride removal efficiency ofAOMO varied significantly with percentage of MnO with an optimum value of about I11% of manganese oxide in the adsorbent. The optimum dose of the adsorbent was 4 g/L which corresponds to the equilibrium adsorption capacity of 4.8 mg F-/g. Both the removal efficiency and adsorption capacity showed an increasing trend with an increase in initial fluoride concentration of the water. The pH for optimum fluoride removal was found to be in the range between 5 and 7. The adsorption data were analysed using the Freundlich, Langmuir, and Dubinirn-Radushkevich models. The minimum adsorption capacity obtained from the non-linear Freundlich isotherm model was 4.94 mg F-/g and the maximum capacity from the Langmuir isotherm method was 19.2mg F-/g. The experimental data of fluoride adsorption on AOMO fitted well to the Freundlich isotherm model. Kinetic studies showed that the adsorption is well described by a non-linear pseudo-second-order reaction model with an average rate constant of 3

  15. Properties of native ultrathin aluminium oxide tunnel barriers

    CERN Document Server

    Gloos, K; Pekola, J P

    2003-01-01

    We have investigated planar metal-insulator-metal tunnel junctions with aluminium oxide as the dielectricum. These oxide barriers were grown on an aluminium electrode in pure oxygen at room temperature till saturation. By applying the Simmons model we derived discrete widths of the tunnelling barrier, separated by DELTA s approx 0.38 nm. This corresponds to the addition of single layers of oxygen atoms. The minimum thickness of s sub 0 approx 0.54 nm is then due to a double layer of oxygen. We found a strong and systematic dependence of the barrier height on the barrier thickness. Breakdown fields up to 5 GV m sup - sup 1 were reached. They decreased strongly with increasing barrier thickness. Electrical breakdown could be described by a metal-insulator like transition of the dielectric barrier due to the large density of tunnelling electrons.

  16. Electrocoagulation of cutting oil emulsions using aluminium plate electrodes.

    Science.gov (United States)

    Bensadok, K; Benammar, S; Lapicque, F; Nezzal, G

    2008-03-21

    The treatment of very concentrated oil-water emulsions by electrocoagulation (EC) was experimentally investigated as a pre-treatment step prior to a membrane process. The oil-water emulsion was prepared from a cutting mineral oil B22 currently used for drilling and machining operations. The electrocoagulation progress was followed by the measurement of COD, turbidity and pH in a batch process with recirculation of the liquid. This study is mainly focused on the effects of operating parameters such as initial pH, current density, oil concentration and recirculation rate, on the de-emulsification efficiency. Kinetic curves showed that the EC process exhibits two phases: a "reactive phase" during which the COD and the turbidity removals increase with electrolysis, and a stationary phase for which further aluminium dissolution is useless in the pollution abatement. The results showed that the treatment efficiency increases with increasing current density, but decreases with oil concentration. It appears that treatment of the considered cutting oil is completed through dissolution of around 10mgAl/g oil, with a slight positive effect of the liquid flow rate. Best results are also obtained with initial pH near 7. PMID:17706345

  17. Determination of anisotropy in impact toughness of aluminium alloy 2024 T3 plate

    Science.gov (United States)

    Siddiqui, M. H.; Hashmi, F.; Junaid, A.

    The research was aimed to quantify the existence of anisotropy in fracture toughness of aluminium alloy 2024 T3 plate (used in aircraft structural members). It was further needed to establish the direction in which the fracture toughness of aluminium alloy 2024 T3 plate is maximum and minimum. This could help ascertain the structural integrity of aircraft structural components; also while designing new components, the knowledge of variation in toughness with respect to direction helps in economizing dead weight of the aircraft. In this research, pursued at the College of Aeronautical Engineering, the anisotropy in toughness of aluminium alloy 2024 T3 plate was analysed using the Charpy V-notch impact toughness test. The effect of specimen orientation on the impact toughness values of the alloy was investigated and compared with known results to verify the reliability of the work and to ascertain the extent of anisotropy in fracture toughness of the said alloy. Charpy impact tests were carried out on ASTM E 23 standard specimens machined at a reference laboratory at room temperature (23° C +/- 2° C). Four different specimen orientations analysed for the purpose of this study were L-S, L-T, T-S and T-L directions. Subsequently, the results obtained at the research centre were then analysed and correlated with morphology of microstructure of the material to establish the reliability of the experimental results. Moreover, an analysis was also done to cater for the possible errors that could affect the fracture toughness values obtained from experimental results. It was concluded that the T-S orientation of the plate had maximum toughness, whereas, minimum toughness was observed in L-T direction.

  18. Steam assisted oxide growth on aluminium alloys using oxidative chemistries: Part I Microstructural investigation

    Science.gov (United States)

    Din, Rameez Ud; Piotrowska, Kamila; Gudla, Visweswara Chakravarthy; Jellesen, Morten Stendahl; Ambat, Rajan

    2015-11-01

    The surface treatment of aluminium alloys under steam containing KMnO4 and HNO3 resulted in the formation of an oxide layer having a thickness of up to 825 nm. The use of KMnO4 and HNO3 in the steam resulted in incorporation of the respective chemical species into the oxide layer. Steam treatment with solution containing HNO3 caused dissolution of Cu and Si from the intermetallic particles in the aluminium substrate. The growth rate of oxide layer was observed to be a function of MnO4- and NO3- ions present in the aqueous solution. The NO3- ions exhibit higher affinity towards the intermetallic particles resulting in poor coverage by the steam generated oxide layer compared to the coating formed using MnO4- ions. Further, increase in the concentration of NO3- ions in the solution retards precipitation of the steam generated aluminium hydroxide layer.

  19. Steam assisted oxide growth on aluminium alloys using oxidative chemistries: Part I Microstructural investigation

    DEFF Research Database (Denmark)

    Din, Rameez Ud; Piotrowska, Kamila; Gudla, Visweswara Chakravarthy;

    2015-01-01

    The surface treatment of aluminium alloys under steam containing KMnO4 and HNO3resulted in the formation of an oxide layer having a thickness of up to 825 nm. The use of KMnO4 and HNO3 in the steam resulted in incorporation of the respective chemical species into the oxide layer. Steam treatment...

  20. 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...

  1. Behaviour of Thin Aluminium Plates Subjected to Impact by Ogive-nosed Projectiles

    Directory of Open Access Journals (Sweden)

    M.A. Iqbal

    2006-11-01

    Full Text Available A pneumatic gas gun has been used to fire ogive-nosed projectiles on aluminium plates(1mm at varying impact velocities above the ballistic limit. Impact and residual velocities havebeen measured. Deformation of the target plate was studied. Experimental results formed thebasis of a subsequent finite element analysis of the problem using the ABAQUS 6.3 code. TheJohnson-Cook plastic flow and fracture model available in the code were utilised. Explicit finiteelement analysis has been performed to model the perforation phenomenon. Numerical resultswere significantly improved by reducing the element size up to a certain level beyond which nosignificant variation in the results was observed. Adaptive meshing has been found to be usefulin obtaining the accurate results and avoiding the problem of premature termination of theprogram due to excessive element distortion. Experimental and numerical results are comparedand a good agreement between the two has been found.

  2. Low temperature oxidation of niobium alloy with silicon-aluminium coating

    International Nuclear Information System (INIS)

    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

  3. Characterization of steam generated anti-corrosive oxide films on Aluminium alloys

    DEFF Research Database (Denmark)

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

    2014-01-01

    Aluminium and its alloys are widely used in structural and transportation 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...... 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...

  4. Steam assisted oxide growth on aluminium alloys using oxidative chemistries: Part II corrosion performance

    Science.gov (United States)

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

    2015-11-01

    Surface treatment of aluminium alloys using steam with oxidative chemistries, namely KMnO4 and HNO3 resulted in accelerated growth of oxide on aluminium alloys. Detailed investigation of the corrosion performance of the treated surfaces was carried out using potentiodynamic polarisation and standard industrial test methods such as acetic acid salt spray (AASS) and filiform corrosion on commercial AA6060 alloy. Barrier properties of the film including adhesion were evaluated using tape test under wet and dry conditions. Electrochemical results showed reduced cathodic and anodic activity, while the protection provided by steam treatment with HNO3 was a function of the concentration of NO3- ions. The coating generated by inclusion of KMnO4 showed highest resistance to filiform corrosion. Overall, the performance of the steam treated surfaces under filiform corrosion and AASS test was a result of the local coverage of the alloy microstructure resulting from steam containing with KMnO4 and HNO3.

  5. Morphology of Platinum Nanowire Array Electrodeposited Within Anodic Aluminium Oxide Template Characterized by Atomic Force Microscopy

    Institute of Scientific and Technical Information of China (English)

    孔令斌; 陆梅; 李梦轲; 郭新勇; 力虎林

    2003-01-01

    Uniform platinum nanowires were synthesized by electrodepositing the platinum under a very low altering current frequency (20Hz) and increasing voltage (5-15 V) in the pores of anodic aluminium oxide (AAO) template.Atomic force microscopy observation indicates that the template membranes we obtained have hexagonally closepacked nanochannels. The platinum nanowires have highly ordered arrays after partially dissolving the aluminium oxide membrane. With the increasing dissolving time, the platinum nanowire array collapsed. A concave topography of the aluminium substrate was observed after the aluminium oxide membrane was dissolved completely and the platinum nanowires were released from the template. Platinum nanowires were also characterized by transmission electron microscopy and the phase structure of the Al/AAO/Pt composite was proven by x-ray diffraction.

  6. Metallographic characterisation of Al6061-T6 aluminium plates subjected to ballistic impact

    Energy Technology Data Exchange (ETDEWEB)

    Manes, A., E-mail: andrea.manes@polimi.it; Pagani, M.; Saponara, M.; Mombelli, D.; Mapelli, C.; Giglio, M.

    2014-07-01

    Al6061-T6 aluminium single layer plates, of different thickness, impacted by two different 7.62 mm Armour Piercing projectiles are studied from a metallographic point of view. The material behaviour after ballistic impact is investigated by optical and scanning electron microscopy as well as by micro-hardness tests. The study allows one to highlight the physical phenomena that happen during the impact: the formation of adiabatic shear bands (ASB), the evolution of softening and hardening phenomena, the creation of petalling, plugging and the formation of a melted film between the target and the penetrator as well as the localised failure mechanism. The thermo-mechanical effects on the target and the penetrator material have been examined in order to investigate in the physical phenomena ruling the ballistic damage; the differences between the two types of impactors are also highlighted. Among interesting findings, it has been noticed that a complete penetration is less detrimental and tungsten core projectile seems more damaging for the structural integrity of Al6061-T6 plates. A complete penetration allows the material to better dissipate the plastic deformation energy induced by bullet whereas the arrest increases localised material softening effect resulting in the formation of ASB. Although the creation of numerical models is not the aim of the present paper, the findings could be useful for the building of a modelling approach capable of replicating all the involved phenomena in details.

  7. Thermal Analysis on Butt Welded Aluminium Alloy AA7075 Plate Using FEM

    Directory of Open Access Journals (Sweden)

    M. Pal Pandi

    2014-03-01

    Full Text Available Thermo-mechanical finite element analysis has been performed to assess the residual stress in the butt weld joints of aluminium Alloy AA7075 plates by utilizing the commercial software package ABAQUS. This paper presents an efficient FE technique using equivalent load to precisely predict welding deformations and residual stresses in butt joints. The radial heat flux distribution is considered on the top surface of the weldment. Convective and radiative heat losses are taken into account through boundary conditions for the outward heat flux. Linear FE transient thermal analysis is performed using surface heat source model with Gaussian distribution to compute highest temperature in AA7075 plates. The objective of this project is to simulate the welding process by using the finite element method. After the model is built and verified, the main objective of this project is to study the effects of varying the welding process parameters on the thermo-mechanical responses. In addition to that, the aim of this research is also to find a relationship between welding parameters and the responses of single pass butt welding are evaluated through the finite element analysis. The study of this paper covers the effects of varying heat input, welding speed on the thermo-mechanical responses of the weldment after cooling down to room temperature.

  8. Metallographic characterisation of Al6061-T6 aluminium plates subjected to ballistic impact

    International Nuclear Information System (INIS)

    Al6061-T6 aluminium single layer plates, of different thickness, impacted by two different 7.62 mm Armour Piercing projectiles are studied from a metallographic point of view. The material behaviour after ballistic impact is investigated by optical and scanning electron microscopy as well as by micro-hardness tests. The study allows one to highlight the physical phenomena that happen during the impact: the formation of adiabatic shear bands (ASB), the evolution of softening and hardening phenomena, the creation of petalling, plugging and the formation of a melted film between the target and the penetrator as well as the localised failure mechanism. The thermo-mechanical effects on the target and the penetrator material have been examined in order to investigate in the physical phenomena ruling the ballistic damage; the differences between the two types of impactors are also highlighted. Among interesting findings, it has been noticed that a complete penetration is less detrimental and tungsten core projectile seems more damaging for the structural integrity of Al6061-T6 plates. A complete penetration allows the material to better dissipate the plastic deformation energy induced by bullet whereas the arrest increases localised material softening effect resulting in the formation of ASB. Although the creation of numerical models is not the aim of the present paper, the findings could be useful for the building of a modelling approach capable of replicating all the involved phenomena in details

  9. CNTs tuning and vertical alignment in anodic aluminium oxide membrane

    Institute of Scientific and Technical Information of China (English)

    Maria Sarno; Diana Sannino; Caterina Leone; Paolo Ciambelli

    2012-01-01

    Anodic aluminium oxide (AAOM) membranes were used for template growth of carbon nanotubes (CNT) inside their pores by chemical vapour deposition (CVD) of different hydrocarbons,in the absence of transition metal catalyst.A composite material,containing one nanotube for each channel,having the same length as the membrane thickness and the external diameter close to the diameter of the membrane holes,was obtained.Yield,selectivity,and quality of CNTs in terms of diameter (up to very thin CNT),carbon order,length,arrangement (i.e.number of tubes for each channel),purity,that are critical requisites for several applications were optimized by investigating the effect of changing the hydrocarbon feedstock gas,also in the presence of hydrogen.The samples produced using methane as a feedstock have a well ordered structure.The role of the alumina channels surface during the CNT growth has been investigated and its catalytic activity has been proved for the first time.

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

    CERN Document Server

    Schulte, Marius

    2012-01-01

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

  11. ENERGETIC VALORISATION OF SEMI-RIGID AND FLEXIBLE ALUMINIUM PACKAGING BY OXIDATION AT HIGH TEMPERATURE

    OpenAIRE

    López Gómez, Félix Antonio; Román, Carlos P.; García-Díaz, I.; Alguacil, Francisco José; Gómez-Paniagua, M.

    2013-01-01

    This work reports the energy recovered from semi-rigid and flexible aluminium packaging by oxidation at 850ºC in an air atmosphere enriched with 6% oxygen. The physical properties of the different packagings were determined, including their metallic aluminium contents. Their ash contents were determined according to standard ISO 1171:2000. The net calorific value, the required energy, and the calorific gain associated with each, were determined following standards BS EN 13431:2000 and UNE EN...

  12. Modified Layer-Removal Method for Measurement of Residual Stress in Pre-stretched Aluminium Alloy Plate

    Institute of Scientific and Technical Information of China (English)

    Liangbao Liu; Jianfei Sun; Wuyi Chen; Pengfei Sun

    2015-01-01

    Residual stress is one of the factors affecting the machining deformation of monolithic structure parts in the aviation industry. Thus, the studies on machining deformation rules induced by residual stresses largely depend on correctly and efficiently measuring the residual stresses of workpieces. A modified layer⁃removal method is proposed to measure residual stress by analysing the characteristics of a traditional layer⁃removal method. The coefficients of strain release are then deduced according to the simulation results using the finite element method ( FEM) . Moreover, the residual stress in a 7075T651 aluminium alloy plate is measured using the proposed method, and the results are then analyzed and compared with the data obtained by the traditional methods. The analysis indicates that the modified layer⁃removal method is effective and practical for measuring the residual stress distribution in pre⁃stretched aluminium alloy plates.

  13. Preparation of Aluminium Oxynitride by Carbothermal Reduction of Aluminium Oxide in a Flowing N2 Atmosphere

    Institute of Scientific and Technical Information of China (English)

    LIYa-wei; YUANRun-zhang; 等

    1996-01-01

    Carbothermal reduction of alumina into aluminium oxynitride(AlON) spinel in a flowing nitrogen atmosphere was studied.The effects of Al2O3/C ratio temperature,soaking time,heating rate molding pressure of samples,and nitrogen flow rate on reactions were investigated.Then the stability of AlON was elucidated and AlON wa confirmed as an intermediate compound in reduction of alumina.

  14. Oxidation and waste-to-energy output of aluminium waste packaging during incineration: A laboratory study.

    Science.gov (United States)

    López, Félix A; Román, Carlos Pérez; García-Díaz, Irene; Alguacil, Francisco J

    2015-09-01

    This work reports the oxidation behaviour and waste-to-energy output of different semi-rigid and flexible aluminium packagings when incinerated at 850°C in an air atmosphere enriched with 6% oxygen, in the laboratory setting. The physical properties of the different packagings were determined, including their metallic aluminium contents. The ash contents of their combustion products were determined according to standard BS ISO 1171:2010. The net calorific value, the required energy, and the calorific gain associated with each packaging type were determined following standard BS EN 13431:2004. Packagings with an aluminium lamina thickness of >50μm did not fully oxidise. During incineration, the weight-for-weight waste-to-energy output of the packagings with thick aluminium lamina was lower than that of packagings with thin lamina. The calorific gain depended on the degree of oxidation of the metallic aluminium, but was greater than zero for all the packagings studied. Waste aluminium may therefore be said to act as an energy source in municipal solid waste incineration systems.

  15. Thermoluminescent response of aluminium oxide thin films subject to gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Arrieta, A.; Escobar A, L.; Camps, E.; Villagran, E.; Gonzalez, P.R

    2006-07-01

    The thermoluminescent (TL) properties of amorphous aluminium oxide thin films (thicknesses as low as 0.3 {mu}m) subjected to gamma (Co-60) irradiation are reported. Aluminium oxide thin films were prepared by laser ablation from an Al{sub 2}O{sub 3} target using a Nd: YAG laser with emission at the fundamental line. The films were exposed to gamma radiation (Co-60) in order to study their TL response. Thermoluminescence glow curves exhibited two peaks at 110 and 176 C. The high temperature peak shows good stability and 30% fading in the first 5 days after irradiation. A linear relationship between absorbed dose and the thermoluminescent response for doses span from 150 mGy to 100 Gy was observed. These results suggest that aluminium oxide thin films are suitable for detection and monitoring of gamma radiation. (Author)

  16. Determination of oxide film thickness on aluminium using 14-MeV neutron activation and BET method

    International Nuclear Information System (INIS)

    A new method is described for the determination of the mean film thickness of aluminium oxides by 14-MeV neutron activation analysis of the oxygen and by BET measurement of the surface area. The mean film thickness obtained is independent of the surface roughness. Stable oxide films consisting of only a few atomic layers of oxygen are detected on aluminium. (author)

  17. TRANSPARENT CONDUCTING OXIDE SYNTHESIS OF ALUMINIUM DOPED ZINC OXIDES BY CHEMICAL COPRECIPITATION

    Directory of Open Access Journals (Sweden)

    Silvia Maioco

    2013-03-01

    Full Text Available Aluminium doped zinc oxides (AZO are promising replacements for tin doped indium oxides (ITO but thin films show a wide range of physical properties strongly dependent on deposition process conditions. Submicrometric 1% aluminum doped zinc oxide ceramics (AZO are examined, prepared by coprecipitation, from Zn(NO32 and Al(NO33 aqueous solutions, sintered at 1200°C and subsequently annealed in 10-16 atm controlled oxygen fugacity atmospheres, at 1000°C. Electrical resistivity diminishes by two orders of magnitude after two hours of annealing and the Seebeck coefficient gradually changes from -140 to -50 µV/K within 8 h. It is concluded that increased mobility is dominant over the increased carrier density, induced by changes in metal-oxygen stoichiometry

  18. Effects of Hard Surface Grinding and Activation on Electroless-Nickel Plating on Cast Aluminium Alloy Substrates

    Directory of Open Access Journals (Sweden)

    Olawale Olarewaju Ajibola

    2014-01-01

    Full Text Available This work examined effects of hard surface polishing grits and activation on electroless-nickel (EN plating on cast aluminium alloy substrates in sodium hypophosphite baths. As-received aluminium alloy sample sourced from automobile hydraulic brake master cylinder piston was melted in electric furnace and sand cast into rod. The cast samples were polished using different grits (60 μm–1200 μm before plating. The effects on adhesion, appearance, and quantity of EN deposits on substrates were studied. Observation shows that the quantity of EN deposit is partly dependent on the alloy type and roughness of the surface of the substrates, whereas the adhesion and brightness are not solely controlled by the degree of surface polishing. The best yield in terms of adhesion and appearance was obtained from the activation in zincate and palladium chloride solutions. Higher plating rates (g/mm2/min of 3.01E-05, 2.41E-05, and 2.90E-05 were obtained from chromate, zincate, and chloride than 8.49E-06, 8.86E-06, and 1.69E-05 as obtained from HCl etched, NaOH, and H2O activated surfaces, respectively.

  19. Transmittance and Refractive Index of the Lanthanum Strontium Aluminium Tantalum Oxide Crystal

    Institute of Scientific and Technical Information of China (English)

    HU Bo-Qing; WANG Xiao-Ming; ZHOU Tang; ZHAO Zong-Yuan; WU Xing; CHEN Xiao-Long

    2001-01-01

    The lanthanum strontium aluminium tantalum oxide (LSAT) crystal is grown by means of a floating or pulling method. Its optical transmittance, refractive indices in visible and near-infrared areas and its dispersion curve are reported. The transparence range of LSAT is from 0.45 to 4.2μm and its refractive index is 2.0244.

  20. High-speed deposition of protective films of aluminium oxide by the method of reactive magnetron sputtering

    International Nuclear Information System (INIS)

    The high optical characteristics of aluminium films made them attractive for different functional and decorative applications. It is well-known that the corrosion resistance of alloying is determined by the presence of the oxide film on its surface, but on the aluminium films, deposited by vacuum methods, the resistance is extremely low resulting in the relatively rapid failure of the coating. At present, there is a large number of methods of depositing the films of aluminium oxide. In most cases, it is recommended to use reactive magnetron sputtering of an aluminium target in a magnetron spraying system (MSS) using direct current, on dispersion of the target of aluminium oxide in a high-frequency MSS

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

    Science.gov (United States)

    Sharma, Deep Raj; Sunkaria, Aditya; Wani, Willayat Yousuf; Sharma, Reeta Kumari; Kandimalla, Ramesh J L; Bal, Amanjit; Gill, Kiran Dip

    2013-12-01

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

  2. Temperature and thermal stress fields during the pulse train of long-pulse laser irradiating aluminium alloy plate

    Science.gov (United States)

    Zhang, Wei; Jin, Guangyong; Gu, Xiu-ying

    2014-12-01

    Based on Von Mises yield criterion and elasto-plastic constitutive equations, an axisymmetric finite element model of a Gaussian laser beam irradiating a metal substrate was established. In the model of finite element, the finite difference hybrid algorithm is used to solve the problem of transient temperature field and stress field. Taking nonlinear thermal and mechanical properties into account, transient distributions of temperature field and stress fields generated by the pulse train of long-pulse laser in a piece of aluminium alloy plate were computed by the model. Moreover,distributions as well as histories of temperature and stress fields were obtained. Finite element analysis software COMSOL is used to simulate the Temperature and thermal stress fields during the pulse train of long-pulse laser irradiating 7A04 aluminium alloy plate. By the analysis of the results, it is found that Mises equivalent stress on the target surface distribute within the scope of the center of a certain radius. However, the stress is becoming smaller where far away from the center. Futhermore, the Mises equivalent stress almost does not effect on stress damage while the Mises equivalent stress is far less than the yield strength of aluminum alloy targets. Because of the good thermal conductivity of 7A04 aluminum alloy, thermal diffusion is extremely quick after laser irradiate. As a result, for the multi-pulsed laser, 7A04 aluminum alloy will not produce obvious temperature accumulation when the laser frequency is less than or equal to 10 Hz. The result of this paper provides theoretical foundation not only for research of theories of 7A04 aluminium alloy and its numerical simulation under laser radiation but also for long-pulse laser technology and widening its application scope.

  3. In situ study of the initiation of hydrogen bubbles at the aluminium metal/oxide interface

    Science.gov (United States)

    Xie, De-Gang; Wang, Zhang-Jie; Sun, Jun; Li, Ju; Ma, Evan; Shan, Zhi-Wei

    2015-09-01

    The presence of excess hydrogen at the interface between a metal substrate and a protective oxide can cause blistering and spallation of the scale. However, it remains unclear how nanoscale bubbles manage to reach the critical size in the first place. Here, we perform in situ environmental transmission electron microscopy experiments of the aluminium metal/oxide interface under hydrogen exposure. It is found that once the interface is weakened by hydrogen segregation, surface diffusion of Al atoms initiates the formation of faceted cavities on the metal side, driven by Wulff reconstruction. The morphology and growth rate of these cavities are highly sensitive to the crystallographic orientation of the aluminium substrate. Once the cavities grow to a critical size, the internal gas pressure can become great enough to blister the oxide layer. Our findings have implications for understanding hydrogen damage of interfaces.

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

    Science.gov (United States)

    Mannello, F; Ligi, D; Canale, M

    2013-11-01

    The human breast is likely exposed to Al (aluminium) from many sources including diet and personal care products. Underarm applications of aluminium salt-based antiperspirant provide a possible long-term source of exposure, especially after underarm applications to shaved and abraded skin. Al research in breast fluids likely reflects the intraductal microenvironment. We found increased levels of aluminium in noninvasively collected nipple aspirate fluids (NAF) from 19 breast cancer patients compared with 16 healthy control subjects (268 vs 131 μg/l, respectively; p Aluminium content and carbonyl levels showed a significant positive linear correlation (r(2) 0.6628, p aluminium salts) we also found a significantly increased levels of pro-inflammatory cytokines (IL-1β, IL-6, IL-12 p70, and TNF-α) and chemoattractant CC and CXC chemokines (IL-8, MIP-1α and MCP-1). In 12 invasive cancer NAF samples we found a significant positive linear correlation among aluminium, carbonyls and pro-inflammatory IL-6 cytokine (Y = 64.79x-39.63, r(2) 0.8192, p aluminium ions in oxidative and inflammatory status perturbations of breast cancer microenvironment, suggesting aluminium accumulation in breast microenvironment as a possible risk factor for oxidative/inflammatory phenotype of breast cells.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-12-01

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

  6. Porosity Study of Hybrid Silica Mesostructure in Aluminium Oxide Membrane Columnar by Cyclic Voltammetry Method

    Directory of Open Access Journals (Sweden)

    M.N. Jalil

    2011-12-01

    Full Text Available Silica mesostructure has been grown within with a porous aluminium oxide membrane columnar material (hybrid-AOM. This was prepared using a sol-gel technique with Pluronic P123 triblock copolymer as the structure-directing agent and tetraethyl orthosilicate as the inorganic source. The porosity of the hybrid-AOM after ethanol extraction was calculated from the cyclic voltammetry response of a neutral probe (FcMeOH, using Randles-Sevčik equation.

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

    CERN Document Server

    Xue Wen Bin; Deng Zhi Wei; Chen Ru Yi; Li Yong Liang; Zhang Ton Ghe

    2002-01-01

    A determination of the phase constituents of ceramic coatings produced on Al-Cu-Mg alloy by microarc discharge in alkaline solution was performed using x-ray diffraction. The profiles of the hardness, H, and elastic modulus, E, across the ceramic coating were determined by means of nanoindentation. In addition, a study of the influence of microarc oxidation coatings on the tensile properties of the aluminium alloy was also carried out. The results show that the H-and E-profiles are similar, and both of them exhibit a maximum value at the same depth of coating. The distribution of the alpha-Al sub 2 O sub 3 phase content determines the H- and E-profiles of the coatings. The tensile properties of 2024 aluminium alloy show less change after the alloy has undergone microarc discharge surface treatment.

  8. Ultraviolet sensing properties of polyvinyl alcohol-coated aluminium-doped zinc oxide nanorods

    Indian Academy of Sciences (India)

    Kanchan Saxena; Amit Kumar; Nishant Malik; Pramod Kumar; V K Jain

    2014-04-01

    Undoped and aluminium (Al)-doped zinc oxide (ZnO) nanorods have been synthesized by electrochemical route. The synthesized materials have been characterized by X-ray diffraction, UV–visible spectrometer and scanning electron microscope. The Al-doped ZnO nanorods have been coated with polyvinyl alcohol. Current–voltage characteristics have been investigated in dark and under UV-light illumination. Aluminium doping in ZnO increase its electrical conductivity and further polyvinyl alcohol coating on Al-doped ZnO increase UV sensitivity of the material. Response and recovery time of Al-doped ZnO and PVA-coated Al-doped ZnO nanorods have been recorded. PVA-coated Al-doped ZnO nanorods shows very fast response and recovery time of 10 s in comparison to uncoated ZnO (20 min) nanorods.

  9. Chemical composition and morphology of oxidic ceramics at filtration of steel deoxidised by aluminium

    Directory of Open Access Journals (Sweden)

    J. Bažan

    2009-10-01

    Full Text Available Composition and morphology of filter ceramics were investigated during filtration of steel deoxidised by aluminium. Filtration was realized with use of filters based on oxidic ceramics Cr2O3, TiO2, SiO2, ZrO2, Al2O3, 3Al2O3•2SiO2 and MgO•Al2O3. It was established that change of interphase (coating occurs during filtration of steel on the surface of capillaries of ceramics, where content of basic oxidic component decreases. Loss of oxidic component in the coating is replaced by increase of oxides of manganese and iron and it is great extent inversely proportional to the value of Gibbs’ energy of oxide, which forms this initial basis of ceramics.

  10. Development of a new aluminium matrix composite reinforced with iron oxide (Fe3O4

    Directory of Open Access Journals (Sweden)

    E. Bayraktar

    2010-01-01

    Full Text Available Purpose: of this paper is to develop new aluminium matrix (intermetallic composites reinforced with iron oxide (Fe3O4 that will be used in aeronautical engineering or in electronic industry. Different parameters such as sintering time and temperature, reinforcement, compact pressure were evaluated. The final purpose of this project is going on to improve conductivity and magnetic permeability of this new composite.Design/methodology/approach: In this paper, a new alternative materials “aluminium–iron oxide (Fe3O4, naturally as the mineral magnetite powder composite” has been developed by using a microwave (in the laboratory scale sintering programme with various aspect ratios, that iron oxide (Fe3O4 particle sizes and aluminium powders together were prepared. This paper contains partially preliminary results of our going-on research project.Findings: Green density increased regularly depending on the compact pressure and percentage of the iron oxide (Fe3O4. Micro and macro porosity was not found due to very clean microwave sintering. Density after microwave sintering was higher than that of traditional sintering in an electrical oven.Research limitations/implications: This project is going on and magnetic permeability and conductivity of this composite will be improved.Practical implications: This composite is new and clean and thanks to the new microwave sintering basically will be used in aeronautical engineering. Microwave heating results in lower energy costs and decreased processing times for many industrial processes.Originality/value: Originality of this paper is to use a new reinforcement in the aluminium matrix composite; Fe3O4-iron oxide. A new method - microwave sintering- has been carried out on this composite.

  11. Positive Biomechanical Effects of Titanium Oxide for Sandblasting Implant Surface as an Alternative to Aluminium Oxide.

    Science.gov (United States)

    Gehrke, Sergio Alexandre; Taschieri, Silvio; Del Fabbro, Massimo; Coelho, Paulo Guilherme

    2015-10-01

    The aim of this study was to evaluate the physico-chemical properties and the in vivo host response of a surface sandblasted with particles of titanium oxide (TiO2) followed by acid etching as an alternative to aluminium oxide. Thirty titanium disks manufactured in the same conditions as the implants and 24 conventional cylindrical implants were used. Half of the implants had a machined surface (Gcon) while in the other half; the surface was treated with particles of TiO2 followed by acid etching (Gexp). Surface characterization was assessed by scanning electron microscope (SEM), energy dispersive X-ray spectrometry (EDS), profilometry, and wettability. For the in vivo test, 12 implants of each group were implanted in the tibia of 6 rabbits, and were reverse torque tested after periods of 30 or 60 days after implantation. Following torque, SEM was utilized to assess residual bone-implant contact. The surface characterization by SEM showed a very homogeneous surface with uniform irregularities for Gexp and a small amount of residues of the blasting procedure, while Gcon presented a surface with minimal irregularities from the machining tools. Wettability test showed decreased contact angle for the Gcon relative to the Gexp. The Gexp removal torque at 30 and 60 days was 28.7%, and 33.2% higher relative to the Gcon, respectively. Blasting the surface with particles of TiO2 represents an adequate option for the surface treatment of dental implants, with minimal risk of contamination by the residual debris from the blasting procedure. PMID:24001048

  12. Deposition of Aluminium Oxide Films by Pulsed Reactive Sputtering

    Institute of Scientific and Technical Information of China (English)

    Xinhui MAO; Bingchu CAI; Maosong WU; Guoping CHEN

    2003-01-01

    Pulsed reactive sputtering is a novel process used to deposit some compound films, which are not deposited by traditional D.C. reactive sputtering easily. In this paper some experimental results about the deposition of Al oxide films by pulsed reactive sputtering are presented. The hysteresis phenomenon of the sputtering voltage and deposition rate with the change of oxygen flow during sputtering process are discussed.

  13. Attenuation of ultrasonic Rayleigh–Lamb waves by small horizontal defects in thin aluminium plates

    OpenAIRE

    Gilchrist, M. D.

    1999-01-01

    The present paper illustrates how horizontal symmetric crack-like defects can be detected rapidly in thin isotropic plates by using longitudinal ultrasonic waves. The use of such longitudinal waves offers the potential of being significantly faster for non-destructively detecting defects than conventional ultrasonic techniques, which rely on transverse waves propagating through the thickness of a plate. Computational and analytical methods are used to predict reflection coefficients due to th...

  14. Mechanical and Abrasive Wear Properties of Anodic Oxide Layers Formed on Aluminium

    Institute of Scientific and Technical Information of China (English)

    W.Bensalah; K.Elleuch; M.Feki; M.Wery; H.F.Ayedi

    2009-01-01

    Aluminium oxide coatings were formed on aluminium substrates in oxalic acid-sulphuric acid bath. Abrasion tests of the obtained anodic layers were carried out on a pin-on-disc machine in accordance with the ISO/DP 825 specifications. The Vickers microhardness, D (HV0.2). and the abrasion weight loss, Wa (mg) were measured. Influence of oxalic acid concentration (Cox), bath temperature (T) and anodic current density (J) on D and Wa has been examined, and the sulphuric acid concentration (Caul) was maintained at 160 g.L-1. It was found that high microhardness and abrasive wear resistance of oxide layers were produced under low temperatures and high current densities with the addition of oxalic acid. The morphology and the composition of the anodic oxide layer were examined by scanning electron microscopy (SEM), atomic force microscopy (AFM), optical microscopy and glow-discharge optical emission spectroscopy (GDOES). It was found that the chemistry of the anodizing electrolyte, temperature, and current density are the controlling factors of the mechanical properties of the anodic oxide layer.

  15. Surface oxide formation during corona discharge treatment of AA 1050 aluminium surfaces

    DEFF Research Database (Denmark)

    Minzari, Daniel; Møller, Per; Kingshott, Peter;

    2008-01-01

    Atmospheric plasmas have traditionally been used as a non-chemical etching process for polymers, but the characteristics of these plasmas could very well be exploited for metals for purposes more than surface cleaning that is presently employed. This paper focuses on how the corona discharge...... process modifies aluminium AA 1050 surface, the oxide growth and resulting corrosion properties. The corona treatment is carried out in atmospheric air. Treated surfaces are characterized using XPS, SEM/EDS, and FIB-FESEM and results suggest that an oxide layer is grown, consisting of mixture of oxide...... and hydroxide. The thickness of the oxide layer extends to 150–300 nm after prolonged treatment. Potentiodynamic polarization experiments show that the corona treatment reduces anodic reactivity of the surface significantly and a moderate reduction of the cathodic reactivity....

  16. EFFECTS OF HOUSING SYSTEMS ON PRODUCTIVE PERFORMANCE OF COMMERCIAL LAYERS FOLLOWING INDUCED MOLTING BY ALUMINIUM OXIDE SUPPLEMENTATION

    Directory of Open Access Journals (Sweden)

    M. YOUSAF AND N. AHMAD1

    2006-07-01

    Full Text Available The project was carried out to compare the performance of molted layers by aluminium oxide supplementation in cages and on litter floor system. Seventy two Single Comb White Leghorn commercial layers (60 weeks old were divided into six experimental units of 12 layers each. These experimental units were randomly divided into two groups, each consisting of three experimental units, one group was reared on litter floor and the other in cages. The layers were provided with 35 gm feed containing 4 gm aluminium oxide/kg of feed for first 14 days of molting period (66-67 weeks of age. The layers showed significant reduction in body weight following induced molting by aluminium oxide under both housing systems. Body weight loss was higher, while feed consumption was lower, in the cages as compared to litter floor system. The layers molted by aluminium oxide showed significantly higher egg production in the cages (P≤0.05 than in litter floor system (P≤0.05. The layers in the subsequent production cycle showed improvement in egg weight, egg shell thickness and Haugh Unit Score. The egg weight and egg shell thickness were higher in the birds kept on litter floor system than those kept in cages (P≥0.05. However, Haugh unit score was higher in the cage system. It was concluded that aluminium oxide can be effectively supplemented for better production performance and improved egg quality in the second production cycle preferably in the cages.

  17. Comparative Evaluation of Antifungal Effect of Titanium, Zirconium and Aluminium Nanoparticles Coated Titanium Plates Against C. albicans

    Science.gov (United States)

    Mohandoss, Karthikeyan; Balasubramaniam, Muthu Kumar

    2016-01-01

    Introduction The topographical modifications may vary from millimeter wide grooves to nano size structures. Recently growing nano technology is rapidly advancing surface engineering in implant dentistry. This advancement has resulted in difference in surface properties including the morphology, chemistry, crystal structure and mechanical properties of the implant. Aim To evaluate the anticandidal effect of titanium, zirconium and aluminium nanoparticles against C. albicans at 24 hours, 72 hours and one week time interval. Materials and Methods According to ISO/TR 11175:1993, the samples were prepared with the dimension of 20mm diameter and 1mm thickness in grade IV titanium. A total of 40 samples were made and the samples were divided into four groups. The samples without coating were Group-A (control), samples coated with titanium nano particles were Group-B, samples coated with zirconium nano particles were Group-C and samples coated with aluminium nano particles were Group-D. The samples were cleaned by sonicating in acetone and subsequently in water three times for 15 min. Then they were treated with TiO2, ZrO2 and Al2O3 nanoparticles. The discs were sterilized under uv radiation and placed in SDA for C.albicans. The colonies were counted in 24, 72 hours and one week intervals. Results The values were statistically analyzed using one-way ANOVA and Tukey HSD Test. Significance p-value was < .001, which showed that significant difference in C.F.U among the groups in titanium coated samples at 24 hours, 72 hours and one week time intervals. Conclusion TiO2 nanoparticles coated titanium plates showed significant anticandidal effect compared to ZrO2 and Al2O3 nanoparticles at 24, 72 hours and one week time interval. PMID:26894177

  18. Development and characterization of ultra-thin dosemeters of aluminium oxide

    International Nuclear Information System (INIS)

    The aim of the present thesis work has been to investigate the thermoluminescent (Tl) response of aluminium oxide thin films with thicknesses of the order of 300 nm prepared by laser ablation. Aluminium oxide thin films show Tl response after they are subject to ultraviolet, beta and gamma radiation. The Tl curves exhibit peaks around 75 C and 169 C for UV radiation, 112 C and 180 C for beta particles and 110 C and 176 C for gamma radiation. In order to improve the Tl response some growth parameters such as power density and distance target-substrate were varied. The relation dose-response shows a non-linear behavior for UV irradiation; a linear behavior for beta-particles dose from 150 mGy to 50 Gy, and a linear behavior for gamma radiation dose from 5 Gy to 100 Gy. The kinetic Tl parameters were determined by Computerized Glow Curve Deconvolution (CGCD) method as well as using analytical methods. The CGCD results show that the high temperature peak is composed by four peaks with maximums in 165.7, 188.1, 215.3, 246.5 C. These obey a second order kinetics. The trap depth (E) values are 1.4, 1.6, 1.8 and 2.0 eV respectively. The different analytical results show a trap depth values of 0.914, 0.82 and 0.656 eV respectively. Oxide aluminium thin films obtained would be a suitable tool owing to their potential applications in clinical dosimetry, in the dose distributions due to weekly penetrating radiation determination, and in interfaces dosimetry. (Author)

  19. Cavitation erosion resistance of microarc oxidation coating on aluminium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Feng [School of Mechanical Engineering, Southeast University, Nanjing, 211189 (China); Jiang, Shuyun, E-mail: jiangshy@seu.edu.cn [School of Mechanical Engineering, Southeast University, Nanjing, 211189 (China); Liang, Jun [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000 (China)

    2013-09-01

    Two ceramic coatings are prepared on 2124 aluminum alloy by microarc oxidation (MAO) technology. To explore the cavitation erosion resistance of the MAO coating, cavitation tests were performed by using a rotating-disk test rig. The mass losses, surface morphologies, chemical compositions and the phase constituents of the samples after cavitation tests were examined by using digital balance, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD), respectively. The results indicate that the MAO coatings can extend the incubation period of aluminum alloy, and thus enhance the cavitation erosion resistance as compared to the untreated aluminum alloy samples. After duration of 63 h cavitation test, a lot of erosion pits and the particles in various shapes can be observed on the surfaces of the aluminum alloy samples, while only a few erosion pits are observed on the MAO coatings. Moreover, the mean depths of erosion on the MAO coatings are lower in the first 30 h and are independent on erosion time. The results show that the cavitation erosion of MAO coating is governed by water mechanical impaction, resulting from the effects of brittle fracture of the MAO coating.

  20. Nuclear analysis of a rare earth containing protective oxide on aluminium

    Energy Technology Data Exchange (ETDEWEB)

    Gorman, J.D.; Paterson, P.J.K. [Royal Melbourne Inst. of Tech., VIC (Australia); Hughes, A.E. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), Melbourne, VIC (Australia). Div. of Materials Science

    1996-12-31

    The aim is study was to examine the thickness of the conversion coating as well as the elemental depth distribution of cerium and molybdenum using Rutherford Backscattering Spectroscopy (RBS), Scanning Electron Microscopy (SEM), Scanning Auger Electron Spectroscopy and Forward Recoil Spectroscopy (FRS). In addition, RBS has been used to examine how changes in processing conditions, particularly the treatment temperatures, influences the coating thickness and Ce distribution at each process step. SEM established that a crazed oxide structure was developed over the matrix of the alloy using the above process steps. RBS was chosen to provide elemental concentration versus depth information on these samples since it is largely insensitive to surface topography when the detector is set to high scattering angles. A other advantage of using RBS for this particular system is that the heavy elements incorporated into the coating such as Ce and Mo because of their high atomic number compared to the aluminium oxide, are well separated from aluminium and oxygen at their higher recoil energies. Forward Recoil Spectroscopy is capable of detecting hydrogen and it has been used to confirm that the coating is hydrated and to establish the hydrogen distribution within the final oxide coating on each alloy. 7 refs., 1 tab., 4 figs.

  1. China’s Aluminium Plate and Strip Companies Suffered a Slump in Profit and Order Amounts

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>The profit and order amounts of China’s alu- minium plate and strip companies dropped in August,according to a survey on basic condi- tions such as the production and operation of these companies conducted by a relevant insti- tution.

  2. Installation of the light tight cover for the SSD modules (the modules are behind the aluminium plate). The silicon sensors are sensitive to light tight, so ambient light will increase the noise and may even damage them.

    CERN Multimedia

    Nooren, G.

    2004-01-01

    Installation of the light tight cover for the SSD modules (the modules are behind the aluminium plate). The silicon sensors are sensitive to light tight , so ambient light will increase the noise and may even damage them.

  3. Experimental Investigation and Prediction of Mechanical Properties of Friction Stir Welded Aluminium Metal Matrix Composite Plates

    Directory of Open Access Journals (Sweden)

    Yahya BOZKURT

    2012-12-01

    Full Text Available Friction stir welding (FSW is a relatively contemporary solid state welding process and has been employed in aerospace, railway, automotive and marine industries for joining of aluminum, magnesium, zinc, titanium, copper alloys, dissimilar metals and thermoplastics. The FSW process parameters such as tool rotation speed, tool traverse speed and tilt angle play an important role in deciding the joining quality. The present study defines the effect of FSW process on the tensile properties of the AA2124/SiC/25p metal matrix composite (MMC plates. Obtained results showed that the joint efficiency decreases by increasing the tool traverse speed while tool rotation speed was kept constant. Second contribution of this study is the application of decision tree technique to predict the tensile properties of friction stir welded MMC plates. It is seen that methodology can be applied with great accuracy.DOI: http://dx.doi.org/10.5755/j01.ms.18.4.3092

  4. Thermal Conductivity Measurement of Submicron-Thick Aluminium Oxide Thin Films by a Transient Thermo-Reflectance Technique

    Institute of Scientific and Technical Information of China (English)

    BAI Su-Yuan; TANG Zhen-An; HUANG Zheng-Xing; YU Jun; WANG Jia-Qi

    2008-01-01

    Thermal conductivity of submicron-thick aluminium oxide thin films prepared by middle frequency magnetron sputtering is measured using a transient thermo-reflectance technique.A three-layer model based on transmission line theory and the gentic algorithm optimization method are employed to obtain the thermal conductivity of thin films and the interfacial thermal resistance.The results show that the average thermal conductivity of 3301000nm aluminium oxide thin films is 3.3Wm-1 K-1 at room temperature.No significant thickness dependence is found.The uncertainty of the measurement is less than 10%.

  5. Aluminium oxide ultrathin-film growth on the Mo(110) surface: a work-function study

    Energy Technology Data Exchange (ETDEWEB)

    Magkoev, T.T. [Department of Physics, State University of North Ossetia, Vladikavkaz (Russian Federation)]. E-mail: magkoev@osetia.ru; Vladimirov, G.G. [Department of Physics, St. Petersburg State University, St. Petersburg (Russian Federation)

    2001-07-16

    Submonolayer-to-multilayer films deposited onto the surface of Mo(110) crystal by thermal evaporation of bulk aluminium oxide in ultrahigh vacuum have been studied by Auger electron spectroscopy, low-energy electron diffraction and work-function measurements (the Anderson method). The Auger spectra of the films at all coverages studied are composed of the lines characteristic for the bulk oxide; no evidence of a metallic Al signal is found. The layer-by-layer growth mode occurs up to two monolayers. Increase of the reflectivity of the low-energy electrons (1 to 4 eV) as the film grows indicates that the film has a reduced density of states, which probably resembles the band gap of the bulk alumina. The films deposited on a substrate held at room temperature are amorphous, whereas deposition at 1300 K results in a hexagonal superstructure. (author). Letter-to-the-editor.

  6. Titanium oxide layers on aluminium substrates produced by the anodic spark deposition process

    International Nuclear Information System (INIS)

    Titanium oxide layers were prepared on pure aluminium substrates by the anodic spark deposition method. The formed crystalline titania (TiO2) phases rutile and anatase and the sodium titanium oxide (Na0.23TiO2) were identified. The corresponding crystallite size values were obtained from X-ray diffraction data by means of the Rietveld method. The crystallite size of each of these phases continuously increases with rising current density. Furthermore, the two-dimensional distribution of the titania phases on the sample surface was determined by Raman spectroscopy. It was found that the rutile/anatase ratio is inhomogeneous distributed on an observed area of 400 x 400 μm2.

  7. Analysis of the effect of transverse power distribution in an involute fuel plate with and without oxide film formation

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R.S.; Hanan, N.A. [Argonne National Lab., IL (United States)

    1998-07-01

    Existing thermal hydraulics computer codes can account for variations in power and temperature in the axial and thickness directions but variations across the width of the plate cannot be accounted for. In the case of fuel plates in an annular core this can lead to significant errors which are accentuated by the presence of an oxide layer that builds up on the aluminium cladding with burnup. This paper uses a three dimensional SINDA model to account for the transverse variations in power. The effect of oxide thickness on these differences is studied in detail. Power distribution and fuel conductivity are also considered. The lower temperatures predicted with the SNDA model result in a greater margin to clad and fuel damage. (author)

  8. Analysis of the effect of transverse power distribution in an involute fuel plate with and without oxide film formation

    International Nuclear Information System (INIS)

    Existing thermal hydraulics computer codes can account for variations in power and temperature in the axial and thickness directions but variations across the width of the plate cannot be accounted for. In the case of fuel plates in an annular core this can lead to significant errors which are accentuated by the presence of an oxide layer that builds up on the aluminium cladding with burnup. This paper uses a three dimensional SINDA model to account for the transverse variations in power. The effect of oxide thickness on these differences is studied in detail. Power distribution and fuel conductivity are also considered. The lower temperatures predicted with the SNDA model result in a greater margin to clad and fuel damage. (author)

  9. Use of aluminium plates to simulate the dosimetry of gems during e-beam irradiation

    International Nuclear Information System (INIS)

    The e-beam technology is used in the industrial irradiation of several products like turf, sterilization of medical products, cosmetics, polymers, food, and gems. More than 70% of the gems commercialized in the world receive treatments similar to those present in nature, including heat, and irradiation, in order to improve their value. Since aluminum has a density similar to that of several commercial gems, this paper presents a study of the penetration of electrons in calibrated aluminum plates simulating several different thicknesses ranging from 5 to 30 mm, and comparing with the one obtained in gems. This allows the monitoring of the dose received by gems during irradiation with e-beam systems measuring the delivered surface dose. This procedure is very important for industrial processing of stones due to the irregularities present on most gems, what makes dosimetry a very complex task. The determination of the thicknesses of the gems for which the surface dose is the lowest dose on the whole product assures the precise determination of the minimum dose received by the gems during industrial processing. (author)

  10. Use of aluminium plates to simulate the dosimetry of gems during e-beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Fortes, Marcio Z.; Sousa, Fernando N.C. de; Boente, Otavio C., E-mail: mzamboti@aceletron.com.b, E-mail: fernando.nuno@aceletron.com.b, E-mail: otavio@aceletron.com.b [Aceletron Irradiacao Industrial, Rio de Janeiro, RJ (Brazil); Sousa, Nuno R.A., E-mail: engenheiro.nuno.sousa@gmail.co [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Dept. de Engenharia Mecanica

    2009-07-01

    The e-beam technology is used in the industrial irradiation of several products like turf, sterilization of medical products, cosmetics, polymers, food, and gems. More than 70% of the gems commercialized in the world receive treatments similar to those present in nature, including heat, and irradiation, in order to improve their value. Since aluminum has a density similar to that of several commercial gems, this paper presents a study of the penetration of electrons in calibrated aluminum plates simulating several different thicknesses ranging from 5 to 30 mm, and comparing with the one obtained in gems. This allows the monitoring of the dose received by gems during irradiation with e-beam systems measuring the delivered surface dose. This procedure is very important for industrial processing of stones due to the irregularities present on most gems, what makes dosimetry a very complex task. The determination of the thicknesses of the gems for which the surface dose is the lowest dose on the whole product assures the precise determination of the minimum dose received by the gems during industrial processing. (author)

  11. Gas-Phase Deposition of Ultrathin Aluminium Oxide Films on Nanoparticles at Ambient Conditions

    Directory of Open Access Journals (Sweden)

    David Valdesueiro

    2015-03-01

    Full Text Available We have deposited aluminium oxide films by atomic layer deposition on titanium oxide nanoparticles in a fluidized bed reactor at 27 ± 3 °C and atmospheric pressure. Working at room temperature allows coating heat-sensitive materials, while working at atmospheric pressure would simplify the scale-up of this process. We performed 4, 7 and 15 cycles by dosing a predefined amount of precursors, i.e., trimethyl aluminium and water. We obtained a growth per cycle of 0.14–0.15 nm determined by transmission electron microscopy (TEM, similar to atomic layer deposition (ALD experiments at a few millibars and ~180 °C. We also increased the amount of precursors dosed by a factor of 2, 4 and 6 compared to the base case, maintaining the same purging time. The growth per cycle (GPC increased, although not linearly, with the dosing time. In addition, we performed an experiment at 170 °C and 1 bar using the dosing times increased by factor 6, and obtained a growth per cycle of 0.16 nm. These results were verified with elemental analysis, which showed a good agreement with the results from TEM pictures. Thermal gravimetric analysis (TGA showed a negligible amount of unreacted molecules inside the alumina films. Overall, the dosage of the precursors is crucial to control precisely the growth of the alumina films at atmospheric pressure and room temperature. Dosing excess of precursor provokes a chemical vapour deposition type of growth due to the physisorption of molecules on the particles, but this can be avoided by working at high temperatures.

  12. Spectroscopic study of plasma during electrolytic oxidation of magnesium-aluminium alloys

    Science.gov (United States)

    Jovović, J.

    2014-12-01

    Plasma during Electrolytic Oxidation (PEO) of magnesium-aluminium alloys is studied in this work by means of Optical Emission Spectroscopy (OES). Spectral line shapes of the Hβ, Al II 704.21 nm and Mg II 448.11 nm line are analyzed to measure plasma electron number density Ne. From the Hβ line profile, two PEO processes characterized by relatively low electron number densities Ne ≈ 1015 cm-3 and Ne ≈ 2 × 1016 cm-3 were discovered while the shape and shift of Al II and Mg II lines revealed the third process characterized by large electron density Ne = (1-2) × 1017 cm-3. Low Ne processes, related with breakdown in gas bubbles and on oxide surface, are not influenced by anode material or electrolyte composition. The ejection of evaporated anode material through oxide layer is designated here as third PEO process. Using the Boltzmann plot technique, electron temperature of 4000 K and 33000 K is determined from relative intensities of Mg I and O II lines, respectively. Several difficulties in the analysis of spectral line shapes are met during this study and the ways to overcome some of the obstacles are demonstrated.

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

    Science.gov (United States)

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

    2012-07-01

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

  14. Application of INAA for investigation of magnesium and aluminium oxide materials

    International Nuclear Information System (INIS)

    The paper presents investigations of changes in optical absorption and photo luminescence spectra of magnesium oxide, and natural and synthetic magnesium aluminium spinel related with the content of transition metal ions (Cr, Fe, Mn) and the irradiation with fast neutrons. Six synthetic single magnesium aluminium spinel crystals with different stoichiometry (MgO·nAl2O3), five natural crystals from Ural and Pamir deposits, and seven MgO crystals were studied. Micro impurities (Cr, Fe, and Mn) and macro component (Mg, Al) quantities have been determined using the instrumental neutron activation analysis technique. Concentrations of impurities in different spinels were found in following ranges: for Cr-1 × 10-4 to 8 × 10-2 %, for Mn-2 × 10-5 to 23 %, for Fe-1 × 10-4 to 1.2 %. Three ranges of luminescence: 380-460, 650-850 and 850-1,050 nm, were established in the most part of the investigated MgO samples. Analysis shows that the intensity of emission in each of these regions is strongly dependent on the concentration of transition metal ions. Great deviation from the stoichiometry of the irradiated MgO·2.8Al2O3 crystal leads to the local structure of α-Al2O3 formation around Cr3+ ions. The orange emission is attributed to Mn2+ in octahedral coordination, it can be assumed that the band at 570 nm is belonging to the complex centre 'Mn2+-F+ (or F centre)'. (author)

  15. Accelerated growth of oxide film on aluminium alloys under steam: Part I: Effects of alloy chemistry and steam vapour pressure on microstructure

    DEFF Research Database (Denmark)

    Din, Rameez Ud; Gudla, Visweswara C.; Jellesen, Morten S.;

    2015-01-01

    at the top. The kinetics of formation of film understeamwas rapid; approx. 350nm thick layers were generated within 5 s of steam treatment, however increase in thickness of the oxide retarded further growth. The enrichment or depletion of different alloying elements at the surface of aluminium as a result...... of alkaline etching pre-treatment influenced the thickness and growth of theoxide. Moreover the steam treatment resulted in the partial oxidation of second phase intermetallic particles present in the aluminium alloy microstructure....

  16. A novel technique for the deposition of aluminium-doped zinc oxide films

    International Nuclear Information System (INIS)

    Aluminium-doped zinc oxide is used in many applications as a transparent conductive oxide coating. Such coatings are often deposited by DC reactive sputtering of metallic targets, or RF sputtering of ceramic targets. Both of these techniques have their limitations. In the DC case, alloy targets are expensive and only allow a single composition per target. Additionally, in the RF case, targets produced by hot-pressing, or sintering may have a tendency to crack unless sputtered at low powers, thus restricting the deposition rate. However, sputtering from blended powder targets offers a potential solution to all of these problems. In this project, therefore, a series of Al-doped ZnO films have been produced by the pulsed DC magnetron sputtering of blended ZnO/Al2O3 powder targets. Initial results, presented here, indicate that high quality, defect-free films can be produced with suitable electrical and optical properties. The crystallinity of the films has been examined by X-ray diffraction, before and after annealing in controlled atmospheres. A thorough investigation of glass substrate cleaning techniques has also been carried out, with the effectiveness of each technique being assessed in terms of the coating-to-substrate adhesion, as measured by the scratch testing method

  17. On adsorption of aluminium and methyl groups on silica for TMA/H2O process in atomic layer deposition of aluminium oxide nano layers

    Indian Academy of Sciences (India)

    Anu Philip; K Rajeev Kumar

    2010-04-01

    A detailed chemisorption mechanism is proposed for the atomic layer deposition (ALD) of aluminium oxide nano layers using trimethyl aluminum (TMA) and water as precursors. Six possible chemisorption mechanisms, complete ligand exchange, partial ligand exchange, simple dissociation, complete dissociation via ligand exchange, complete dissociation and association, are proposed and related parameters like ligand to metal ratio (L/M), concentrations of metal atoms and methyl groups adsorbed are calculated and compared against reported values. The maximum number of methyl groups that can get attached on the surface is calculated in a different way which yields a more realistic value of 6.25 per nm2 substrate area. The dependence of the number of metal atoms adsorbed on OH concentration is explained clearly. It is proposed that a combination of complete ligand exchange and complete dissociation is the most probable chemisorption mechanism taking place at various OH concentrations.

  18. Marker behaviour of implanted xenon during the anodic oxidation of aluminium: evidence and interpretation of dose dependant splitting effect

    International Nuclear Information System (INIS)

    Using 2 MeV lithium ions backscattering and transmission electron microscopy techniques, a part of xenon atoms introduced by implantation in aluminium metal under the initial oxide layer is shown to be tranported by the moving metal-oxide interface during anodic oxidation. From specific anodization conditions (V sup(ct), T = 900C) this splitting of the initial xenon distribution is interpreted in terms of bubble formation and growth above a given local concentration threshold. A schematic model for this behaviour evolution is proposed. This dose dependance is of practical interest in the determination of transport numbers. Although unambiguously measured they may be subject to significant systematic uncertainties which are discussed

  19. Fabrication and optical properties of platinum nanowire arrays on anodic aluminium oxide templates

    Institute of Scientific and Technical Information of China (English)

    高铁仁; 陈子瑜; 彭勇; 李发伸

    2002-01-01

    Arrays of Pt nanowires, fabricated by electrodepositing Pt metal into nanoporous anodic aluminium oxide (AAO)templates, exhibit a preferable optical absorption band in the ultraviolet-visible (UV-VIS) spectra and present a blueshift as the wire aspect ratio increases or its radius decreases. This type of optical property of Pt nanowire/porous alumina composites has been theoretically explored using Maxwell-Garnett (MG) effective medium theory. The MG theory,however, is only applicable to nanowires with an infinitesimally small radius relative to the wavelength of an incident light. The nanowire radius is controlled by the pore radius of the host alumina, which depends on anodizing conditions such as the selected electrolyte, anodizing time, temperature and voltage. The nanowire aspect ratios depend on the amount of Pt deposited into the nanopores of AAO films. The optical absorption properties of the arrays of Pt nanowires with diameters of 24, 55 and 90nm have been investigated by the UV-VIS spectra, which show that the extinction maximum (λmax) shifts to shorter wavelength side as the wire aspect ratio increases or its radius decreases.The results are qualitatively consistent with those calculated based on the MG theory.

  20. Aluminium-doped zinc oxide films prepared by an inorganic sol-gel route

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Rodrigo F.; Zaniquelli, Maria E.D

    2004-02-02

    Thin films of aluminium-doped zinc oxide have been formed on glass using an inorganic sol-gel route and the dip-coating process. The films were formed by the thermal decomposition of a stable precursor colloidal sol prepared by an ethanolic reflux of Zn(CH{sub 3}COO){sub 2}{center_dot}2H{sub 2}O and Al(NO{sub 3}){sub 3}{center_dot}9H{sub 2}O. Lactic acid was used as hydrolysis catalyst and acetylacetone and diethanolamine were added to improve film homogeneity. Thermal analysis was used to investigate the chemical processes during firing of the sols. Atomic force microscopy data revealed morphological changes in the temperature range 200-500 deg. C. The importance of sample firing after each transfer step was evidenced by the quartz crystal microbalance technique. A red shift of the absorption edge was observed for thicker films and the transmittance of the samples decreased with increasing film thickness.

  1. The potential of nanoporous anodic aluminium oxide membranes to influence skin wound repair.

    Science.gov (United States)

    Parkinson, Leigh G; Giles, Natalie L; Adcroft, Katharine F; Fear, Mark W; Wood, Fiona M; Poinern, Gerard E

    2009-12-01

    Cells respond to changes in the environment by altering their phenotype. The ability to influence cell behavior by modifying their environment provides an opportunity for therapeutic application, for example, to promote faster wound healing in response to skin injury. Here, we have modified the preparation of an aluminium oxide template to generate large uniform membranes with differing nano-pore sizes. Epidermal cells (keratinocytes) and dermal cells (fibroblasts) readily adhere to these nanoporous membranes. The pore size appears to influence the rate of cell proliferation and migration, important aspects of cell behavior during wound healing. The suitability of the membrane to act as a dressing after a burn injury was assessed in vivo; application of the membrane demonstrated adherence and conformability to the skin surface of a pig, with no observed degradation or detrimental effect on the repair. Our results suggest that keratinocytes are sensitive to changes in topography at the nanoscale level and that this property may be exploited to improve wound repair after tissue injury.

  2. Indium-doped aluminium oxide as a non-radioactive test aerosol for aerosol experiments

    International Nuclear Information System (INIS)

    For testing inhalation facilities it is advantageous to use a non-radioactive, low toxicity test aerosol which can be detected at low concentrations. These criteria are met by a mechanically generated aerosol of indium-doped alumina. Although some cases of lung fibroses have been associated with the inhalation of aluminium compounds in industry, aluminum oxide aerosols are generally considered to be non-toxic. Indium was chosen as a dopant material because (a) it is not normally present in the lung in detectable amounts, (b) it is chemically similar to aluminum and (c) it can be detected in trace amounts by neutron activation analysis (Friberg et al., 1979). Indium aerosols have the same advantages as radioactive tracers for ease of detection, but they are non-toxic during use. This combination of properties offers advantages that could be of use in a wider range of applications than hitherto used, e.g. in inhalation experiments. This paper describes nose-only inhalation experiments on rats using an aerosol of alumina doped with indium. (author)

  3. Surface decoration of anodic aluminium oxide in synthesis of Nafion (registered) -115 nanowire arrays

    International Nuclear Information System (INIS)

    An extrusion method, using anodic aluminium oxide (AAO) membranes as templates, has been developed to fabricate Nafion[reg] -115 nanowire arrays. Surface decoration of the templates plays an important role in the synthesis of the Nafion[reg] -115 nanowire arrays. By using sodium dodecyl sulfate (SDS) as a surfactant in the surface decoration, the filling rate of the Nafion[reg] -115 nanowires in the corresponding template exceeds 95%, compared with the filling rate of 42% in an undecorated template, while on using cetyltrimethylammonium bromide (CTAB) as a surfactant, the filling rate is only about 20%. Systematical investigations show that the effect of surface decoration is induced by the combination of surface tension and electrostatic force (radial component), of which the radial component of the electrostatic force is more important. This effect is significant in organic nanowire fabrication; furthermore, the as-synthesized organic nanowires would have potential application such as in organic electronics, optoelectronic devices, and nanoscale proton exchange membrane fuel cells

  4. Gold-Catalyzed Growth of Aluminium-Doped Zinc Oxide Nanorods by Sputtering Method

    Directory of Open Access Journals (Sweden)

    A. B. Rosli

    2014-01-01

    Full Text Available Aluminium-doped zinc oxide (AZO nanorods thin films were grown by RF magnetron sputtering on gold (Au metal catalyst. The Au catalyst layers with 5, 10, and 15 nm thickness were deposited on glass substrates by sputtering method followed by annealing for 15 min at 500°C to form Au nanostructures on the glass substrate. The AZO thin films were then deposited on the Au catalyst at different deposition temperature varying from 200 to 500°C. Postdeposition annealing processes of the Au catalyst resulted in different morphologies of the Au catalyst layers depending on their thicknesses. This in turn gave different AZO morphologies which suggest that the Au catalyst layer thickness and the deposition temperature contribute to the growth mechanism of the AZO nanostructures. AZO nanorods thin films having hexagonal wurtzite structure with individual nanorods on the film surface were obtained from the samples deposited on 5 and 10 nm thick Au catalyst with the deposition temperature of 300°C.

  5. Nanowires: properties, applications and synthesis via porous anodic aluminium oxide template

    Indian Academy of Sciences (India)

    Jaya Sarkar; Gobinda Gopal Khan; A Basumallick

    2007-06-01

    Quasi one-dimensional nanowires possess unique electrical, electronic, thermoelectrical, optical, magnetic and chemical properties, which are different from that of their parent counterpart. The physical properties of nanowires are influenced by the morphology of the nanowires, diameter dependent band gap, carrier density of states etc. Nanowires hold lot of promises for different applications. Basic electronic devices like junction diodes, transistors, FETs and logic gates can be fabricated by using semiconductor and superlattice nanowires. Thermoelectric cooling system can be fabricated by using metallic nanowires. Semiconductor nanowire junctions can be used for different opto-electronic applications. Moreover, periodic arrays of magnetic nanowires hold high potential for recording media application. Nanowires are also potential candidates for sensor and bio-medical applications. In the present article, the physical and chemical properties of nanowires along with their probable applications in different fields have been reviewed in detail. The review also includes highlights of the synthesis of nanowires via porous anodic aluminium oxide template since the technique is simple, cost-effective and a low temperature technique.

  6. Oxide growth on aluminium alloys in the presence of ammonium fluoborate

    Energy Technology Data Exchange (ETDEWEB)

    Oliver, J.; Paterson, P.; Flavell, T. [Royal Melbourne Inst. of Tech., VIC (Australia); Biddle, G. [Alcoa Rolled Products (Australia)

    1996-12-31

    The aim of this study as to determine the mechanisms involved in using ammonium fluoborate as a reducing atmosphere when preheating a high magnesium content aluminium alloy. Rutherford Backscattering (RBS) has been the major technique used in the analysis of samples, it revealed significant reduction in both the diffusion of magnesium to the surface and the calculated oxide thickness in the presence of NH{sub 4}BF{sub 4}. At temperatures above 500 deg C in air, SEM images revealed depressions and voids due to incipient melting at various stages, around the grain boundaries. Grain boundaries effectively acted as pipes aiding the diffusion of magnesium to the surface. These results have been verified through compositional analysis with both RBS and auger electron spectroscopy (AES). Results from NH{sub 4}BF{sub 4} atmosphere preheat conditions showed significant improvements. It was verified experimentally that above 500 deg C , AA5182 alloys undergo incipient melting at the grain boundaries with magnesium diffusing through to the surface. 5 refs., 1 fig.

  7. Quercetin protects against aluminium induced oxidative stress and promotes mitochondrial biogenesis via activation of the PGC-1α signaling pathway.

    Science.gov (United States)

    Sharma, Deep Raj; Sunkaria, Aditya; Wani, Willayat Yousuf; Sharma, Reeta Kumari; Verma, Deepika; Priyanka, Kumari; Bal, Amanjit; Gill, Kiran Dip

    2015-12-01

    The present investigation was carried out to elucidate a possible molecular mechanism related to the protective effect of quercetin administration against aluminium-induced oxidative stress on various mitochondrial respiratory complex subunits with special emphasis on the role of PGC-1α and its downstream targets, i.e. NRF-1, NRF-2 and Tfam in mitochondrial biogenesis. Aluminium lactate (10mg/kg b.wt./day) was administered intragastrically to rats, which were pre-treated with quercetin 6h before aluminium (10mg/kg b.wt./day, intragastrically) for 12 weeks. We found a decrease in ROS levels, mitochondrial DNA oxidation and citrate synthase activity in the hippocampus (HC) and corpus striatum (CS) regions of rat brain treated with quercetin. Besides this an increase in the mRNA levels of the mitochondrial encoded subunits - ND1, ND2, ND3, Cyt b, COX1, COX3 and ATPase6 along with increased expression of nuclear encoded subunits COX4, COX5A and COX5B of electron transport chain (ETC). In quercetin treated group an increase in the mitochondrial DNA copy number and mitochondrial content in both the regions of rat brain was observed. The PGC-1α was up regulated in quercetin treated rats along with NRF-1, NRF-2 and Tfam, which act downstream from PGC-1α. Electron microscopy results revealed a significant decrease in the mitochondrial cross-section area, mitochondrial perimeter length and increase in mitochondrial number in case of quercetin treated rats as compared to aluminium treated ones. Therefore it seems quercetin increases mitochondrial biogenesis and makes it an almost ideal flavanoid to control or limit the damage that has been associated with the defective mitochondrial function seen in many neurodegenerative diseases.

  8. Oxidation of an aluminium-magnesium alloy in liquid state. Methodology of determination of mechanisms from not necessarily repeatable experiments

    International Nuclear Information System (INIS)

    This research thesis reports the study of the oxidation of an aluminium-5 pc magnesium alloy in its liquid state in an oxygen environment, using thermogravimetric analysis and that of magnesium in its solid state. In a first part, the author reports a thermodynamic and bibliographical study on magnesium transformation in its solid state (Mg/O2 and Mg/H2O systems, transformation with dry and humid synthetic air, oxidation inhibitors) and on Al-Mg alloy transformation in presence of oxygen (thermodynamic properties of aluminium-rich Al-Mg alloys, Al-Mg/O2/N2 and Al-Mg/O2/N2/H2O systems). The next parts address the selection of reaction systems for the different cases (oxidation of solid magnesium in oxygen, oxidation of the Al-Mg alloy in oxygen), the modelling of the formation of magnesia from solid magnesium and from the Al-Mg alloy, and the modelling of the liquid Al-Mg A5182 alloy oxidation in oxygen

  9. Electrochemical Characterization of Al2 O3 -Ni Thin Film Selective Surface on Aluminium

    OpenAIRE

    KADIRGAN, Figen

    1999-01-01

    Solar thermal collectors represent a widely used type of system for the conversion of solar energy. In order to produce selective coatings on aluminium substrates to be used as absorber plates in high efficiency solar collectors, nickel pigmentation was applied to anodically oxidised surfaces. Electrochemical dc methods are used to study the oxidation of aluminium as functions of the following electrolysis conditions: applied current, pH, temperature and concentration of electrolyte....

  10. Atomic structure and oxygen deficiency of the ultrathin aluminium oxide barrier in Al/AlOx/Al Josephson junctions.

    Science.gov (United States)

    Zeng, Lunjie; Tran, Dung Trung; Tai, Cheuk-Wai; Svensson, Gunnar; Olsson, Eva

    2016-01-01

    Al/AlOx/Al Josephson junctions are the building blocks of a wide range of superconducting quantum devices that are key elements for quantum computers, extremely sensitive magnetometers and radiation detectors. The properties of the junctions and the superconducting quantum devices are determined by the atomic structure of the tunnel barrier. The nanoscale dimension and disordered nature of the barrier oxide have been challenges for the direct experimental investigation of the atomic structure of the tunnel barrier. Here we show that the miniaturized dimension of the barrier and the interfacial interaction between crystalline Al and amorphous AlOx give rise to oxygen deficiency at the metal/oxide interfaces. In the interior of the barrier, the oxide resembles the atomic structure of bulk aluminium oxide. Atomic defects such as oxygen vacancies at the interfaces can be the origin of the two-level systems and contribute to decoherence and noise in superconducting quantum circuits. PMID:27403611

  11. Atomic structure and oxygen deficiency of the ultrathin aluminium oxide barrier in Al/AlOx/Al Josephson junctions

    Science.gov (United States)

    Zeng, Lunjie; Tran, Dung Trung; Tai, Cheuk-Wai; Svensson, Gunnar; Olsson, Eva

    2016-07-01

    Al/AlOx/Al Josephson junctions are the building blocks of a wide range of superconducting quantum devices that are key elements for quantum computers, extremely sensitive magnetometers and radiation detectors. The properties of the junctions and the superconducting quantum devices are determined by the atomic structure of the tunnel barrier. The nanoscale dimension and disordered nature of the barrier oxide have been challenges for the direct experimental investigation of the atomic structure of the tunnel barrier. Here we show that the miniaturized dimension of the barrier and the interfacial interaction between crystalline Al and amorphous AlOx give rise to oxygen deficiency at the metal/oxide interfaces. In the interior of the barrier, the oxide resembles the atomic structure of bulk aluminium oxide. Atomic defects such as oxygen vacancies at the interfaces can be the origin of the two-level systems and contribute to decoherence and noise in superconducting quantum circuits.

  12. Influence of Nanowire Diameter on Structural and Optical Properties of cu Nanowire Synthesized in Anodic Aluminium Oxide Film

    Science.gov (United States)

    Cetinel, A.; Özcelik, Z.

    2016-11-01

    Copper (Cu) nanowire arrays embedded in anodic aluminium oxide films (AAO) on aluminium substrate have been synthesized by alternating current electrochemical deposition. Two-step anodization process has been performed to get the through-hole AAO with ordered nanochannels in 0.3M oxalic acids at DC voltages 30, 40, 50 and 60V, respectively. Structural characterization of the Cu nanowires has been analyzed by scanning electron microscopy (SEM) and X-ray diffraction (or) X-ray diffractometer (XRD). Our SEM analysis has revealed that the diameters of vertically oriented Cu nanowires are 15, 25, 45 and 60nm and the length of Cu nanowires having high packing density is about 15μm. XRD measurement has indicated that polycrystalline Cu nanowires prefer growth orientation along the (111) direction. Optical measurements show that reflection of the Cu nanowires/AAO on aluminium reduces with decreasing diameter of the Cu nanowires. This effect can be associated with increased light scattering from metal nanoparticles near their localized plasmon resonance frequency depending on the size and shape of the nanoparticles.

  13. Investigation of structural, morphological, luminescent and thermal properties of combusted aluminium-based iron oxide

    Science.gov (United States)

    Shinde, S. S.; Rajpure, K. Y.

    2010-12-01

    Nanocomposites of aluminium integrated hematite α-Fe 2O 3 are synthesized by combustion route using aqueous solutions of AR grade ferric trichloride and aluminium nitrate as precursors. The influence of aluminium incorporation on to the morphology, XPS, photoluminescence and thermal properties has been investigated. The FESEM and AFM micrographs depict that the samples are compact and have homogeneously distributed grains of varying sizes (˜20-60 nm). Chemical composition and valence states of constituent elements in hematite are analyzed by XPS. In room temperature photoluminescence (PL) study, we observed strong violet emission around 436 nm without any deep-level emission and a small PL FWHM indicating that the concentrations of defects are responsible for deep-level emissions. The specific heat and thermal conductivity study shows the phonon conduction behavior is dominant. We studied interparticle interactions using complex impedance spectroscopy. We report a new potential candidate for its possible applications in optoelectronics and magnetic devices.

  14. Nanoscale carbon tubules deposited in anodic aluminium oxide template:a study of soft x-ray transmission

    Institute of Scientific and Technical Information of China (English)

    Liu Li-Feng; Zhou Zhen-Ping; Yuan Hua-Jun; Ci Li-Jie; Liu Dong-Fang; Gao Yan; Wang Jian-Xiong; Wang Gang; Zhou Wei-Ya; Zhu Pei-Ping; Cui Ming-Qi; Zheng Lei; Zhu Jie; Zhao Yi-Dong; Song Li; Yan Xiao-Qin

    2004-01-01

    Well-aligned, catalyst-free nanoscale carbon tubules array was prepared by organic compound vapour deposition method using anodic aluminium oxide (AAO) as a template. The experiment of soft x-ray channelling in such carbon tubules array deposited in AAO template was performed at Beijing Synchrotron Radiation Facility. The transmission of x-rays in carbon tubules array with AAO template support was found even higher than that in bare AAO template at high-energy part of energy spectrum though the porous area of the former was smaller than that of the latter. A qualitative explanation is presented to interpret our results.

  15. Mechanism of Nickel-Aluminium Alloy Electroplating

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The effect of operating conditions on the aluminium content of Ni-Al alloy deposit and the catalytic function of NaF on electrodeposition in the nonaqueous solution containing aluminium are investigated.The results indicate that the plated aluminuim content will be increased with the rise of current density in a given range.When the current density is 2.5A/dm2,nickle-aluminium alloy containing 13.1 wt% aluminium will be deposited.The plated aluminium content will be increased by 2wt% as 0.1mol/L NaF is added to the bath.

  16. Autocatalytic silver-plating of aluminium radio frequency waveguides with autocatalytic nickel as the undercoat for space applications

    International Nuclear Information System (INIS)

    Autocatalytic plating, a technique used for evenly coating contoured items with deep cavities, such as microwave components, irrespective of shape and size of the item to be plated, was used in this work to coat a radio frequency waveguide. In this work, a process sequence was developed for autocatalytic silver plating on aluminum base material with autocatalytic nickel as the undercoat. The thickness of the deposited silver depends on variables like temperature, concentration of silver ions in the electrolyte, and the pH of the solution. The influence of these variables was studied under different process conditions. Silver-coated rectangular plates were subjected to various tests, including a bend test, a heat resistance test, a thermal cycling test, a thermo vacuum test, a solderability test, and a humidity resistance test. Autocatalytic silver-coated RF waveguide WR28 was tested for insertion loss and return loss. Autocatalytic silver-plated rectangular plates and waveguides were found to withstand a simulated space environment. (paper)

  17. A corrosion resistant cerium oxide based coating on aluminum alloy 2024 prepared by brush plating

    Energy Technology Data Exchange (ETDEWEB)

    Tang Junlei; Han Zhongzhi [School of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Zuo Yu, E-mail: zuoy@mail.buct.edu.cn [School of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Tang Yuming [School of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China)

    2011-01-15

    Cerium oxide based coatings were prepared on AA2024 Al alloy by brush plating. The characteristic of this technology is that hydrogen peroxide, which usually causes the plating solution to be unstable, is not necessary in the plating electrolyte. The coating showed laminated structures and good adhesive strength with the substrate. X-ray diffraction and X-ray photoelectron spectroscopy analysis showed that the coatings were composed of Ce(III) and Ce(IV) oxides. The brush plated coatings on Al alloys improved corrosion resistance. The influence of plating parameters on structure and corrosion resistance of the cerium oxide based coating was studied.

  18. Welding Stress and Welding Distortion of 6061 Aluminium Alloy Thin Plate%6061铝合金薄板焊接应力与焊接变形

    Institute of Scientific and Technical Information of China (English)

    陈丽华; 封艳

    2013-01-01

    the relationship between the plate size, welding current, welding voltage and welding stress, the welding distortion for 6061 aluminum alloy sheet TIG welding is studied. With the increase of welding current, welding voltage,aluminium alloy of the longitudinal and lateral contraction deformation increase; With the increase of the length of the plate, due to the much more constraint, the plate of the longitudinal residual deformation decrease,for the bending stress in thickness direction increases,the transverse deformation increases. Residual stress of welding is tensile, and the parent metal close to weld is compressive stress, and the rest of the parent metal is tensile stress, the more the welding energy is, the greater the residual stress.%研究了6061铝合金薄板TIG焊焊接应力、焊接变形与焊接电流、焊接电压和板材尺寸的关系.随着焊接线能量的增加,铝合金的纵向和横向收缩变形增加;随着板的长度的增加,由于约束增加,板的纵向残余变形减少,厚度方向的抗弯增大,横向变形增大.板焊后,焊缝处受拉应力,而紧靠焊缝的母材处却受压应力,其余部分受拉应力且焊接线能量越大,残余应力越大.

  19. Morphology, thermal, electrical and electrochemical stability of nano aluminium-oxide-filled polyvinyl alcohol composite gel electrolyte

    Indian Academy of Sciences (India)

    Navin Chand; Neelesh Rai; S L Agrawal; S K Patel

    2011-12-01

    In the present work, an attempt has been made to develop nano aluminium oxide (Al2O3)-filled polyvinyl alcohol (PVA) composite gel electrolytes. Surface morphological studies, thermal behaviour, electrochemical stability and electrical characterization of these composite gel electrolytes have been performed. An increase in the concentration of Al2O3 in composite gel electrolytes increases the amorphous characteristics of pure PVA. Bulk conductivity of composite gel electrolytes increases by an order of magnitude on addition of a nano filler. Maximum conductivity of 5.81 × 10-2 S/cm is observed for 6 wt% Al2O3-filled polymer gel composite electrolytes. Temperature dependence of electrical conductivity shows a combination of Arrhenius and Vogel–Tamman–Fulcher (VTF) nature. Maximum current stability during oxidation and reduction cycle is noticed for 6 wt% Al2O3-filled PVA composite electrolyte, viz. ±1.65 V.

  20. LETTER TO THE EDITOR: Aluminium oxide ultrathin-film growth on the Mo(110) surface: a work-function study

    Science.gov (United States)

    Magkoev, T. T.; Vladimirov, G. G.

    2001-07-01

    Submonolayer-to-multilayer films deposited onto the surface of Mo(110) crystal by thermal evaporation of bulk aluminium oxide in ultrahigh vacuum have been studied by Auger electron spectroscopy, low-energy electron diffraction and work-function measurements (the Anderson method). The Auger spectra of the films at all coverages studied are composed of the lines characteristic for the bulk oxide; no evidence of a metallic Al signal is found. The layer-by-layer growth mode occurs up to two monolayers. Increase of the reflectivity of the low-energy electrons (1 to 4 eV) as the film grows indicates that the film has a reduced density of states, which probably resembles the band gap of the bulk alumina. The films deposited on a substrate held at room temperature are amorphous, whereas deposition at 1300 K results in a hexagonal superstructure.

  1. Preparation and investigations of thermal properties of copper oxide, aluminium oxide and graphite based on new organic phase change material for thermal energy storage

    Indian Academy of Sciences (India)

    Murat Genc; Betul Inci; Zuhal Karagoz Genc; Canan Aksu Canbay; Memet Sekercı

    2015-04-01

    The effects of copper oxide, aluminium oxide and graphite on the thermal and structural properties of the organic phase change material (PCM) were investigated. Ethyl 2-(1H-benzotriazole-1-yl)acetate was selected as the pure PCM. Fourier transform infrared (FT-IR) spectroscopy, X-ray, energy dispersive X-ray (EDX) and scanning electron microscope (SEM) were used to determine the chemical structure, crystalloid phase, chemical composition and microstructure of the composites, respectively. The thermal properties were investigated by differential scanning calorimetry and thermogravimetric analyzer. The FT-IR analyses indicated that there was no chemical interaction between the pure PCM and the supporting materials such as copper oxide, aluminium oxide and graphite. The X-ray diffractograms of the samples were nearly the same, but the peak intensities changed according to the supporting materials. The SEM results showed that the C, N and O elements were well adsorbed into the porous network of the graphite, Al2O3 and CuO. According to the supporting materials, the graphite had the minimum porosity and the maximum crystallite size.

  2. A Reaction Coating on Aluminium Alloys by Laser Processing

    NARCIS (Netherlands)

    Zhou, X.B.; Hosson, J.Th.M. De

    1993-01-01

    An aluminium oxide layer of 100 µm in thickness has been successfully coated on aluminium alloy 6061 and pure aluminium using a powder mixture of silicon oxide and aluminium by laser processing. A strong Al/Al2O3 interface was formed. The exothermic chemical reaction between SiO2 and Al may promote

  3. Electrical behaviour, characteristics and properties of anodic aluminium oxide films coloured by nickel electrodeposition

    OpenAIRE

    Arurault, Laurent; Zamora, Gaël; Vilar, Virginie; Winterton, Peter; Bes, René

    2010-01-01

    Porous anodic films on 1050 aluminium substrate were coloured by AC electrodeposition of nickel. Several experiments were performed at different deposition voltages and nickel concentrations in the electrolyte in order to correlate the applied electrical power to the electrical behaviour, as well as the characteristics and properties of the coatings. The content of nickel inside the coatings reached 1.67 g/m2, depending on the experimental conditions. According to the applied AC voltage in...

  4. Method of aluminium fluoride manufacture

    International Nuclear Information System (INIS)

    The manufacture of aluminium fluoride is based on waste processing in uranium hexafluoride conversion to uranium oxides within the fuel cycle. The conversion is the stoichiometric conversion of uranium hexafluoride with aluminium nitrate to uranyl nitrate. This is extracted from the water phase by phosphoric acid trialkyl ester to an organic solvent and further processed. The discharge water phase is solidified by evaporation to solid aluminium fluoride and nitric acid. (M.S.)

  5. Manipulation of stored charge in anodic aluminium oxide/SiO2 dielectric stacks by the use of pulsed anodisation

    Science.gov (United States)

    Lu, Zhong; Ouyang, Zi; Grant, Nicholas; Wan, Yimao; Yan, Di; Lennon, Alison

    2016-02-01

    A method of fabricating anodic aluminium oxide (AAO) with the capability of manipulating its stored charge is reported. This method involves the use of a pulsed current source to anodise aluminium layers instead of the typically used constant current/voltage source, with the test structures experiencing positive and negative cycles periodically. By tuning the positive cycle percentage, it is demonstrated that the effective stored charge density can be manipulated in a range from -5.2 × 1011 to 2.5 × 1012 q/cm2 when the AAO is formed over a 12 nm SiO2 layer. An investigation of the stored charge distribution in the dielectric stacks indicates a positive fixed charge at the SiO2/Si interface, a negative fixed charge at the AAO/SiO2 interface and a positive bulk charge within the AAO layer. The effective stored charge density and interface states were found to be affected by annealing conditions and it is suggested that oxygen annealing can reduce the bulk positive charge while post-metallisation anneal is most effective in reducing silicon interface defects. Charge manipulation using pulsed anodisation is shown to reduce carrier recombination on boron-diffused silicon surfaces highlighting the potential of the process to be used to tune the electrical properties of dielectric layers so that they can reduce surface recombination on silicon surfaces having different dopant polarity and concentrations.

  6. Accelerated growth of oxide film on aluminium alloys under steam: Part II: Effects of alloy chemistry and steam vapour pressure on corrosion and adhesion performance

    DEFF Research Database (Denmark)

    Din, Rameez Ud; Bordo, Kirill; Jellesen, Morten Stendahl;

    2015-01-01

    The steam treatment of aluminium alloys with varying vapour pressure of steamresulted in the growth of aluminium oxyhydroxide films of thickness range between 450 - 825nm. The surface composition, corrosion resistance, and adhesion of the produced films was characterised by XPS, potentiodynamic...... polarization, acetic acid salt spray, filiform corrosion test, and tape test. The oxide films formed by steam treatment showed good corrosion resistance in NaCl solution by significantly reducing anodic and cathodic activities. The pitting potential of the surface treated with steam was a function...

  7. Self-sealing of unsealed aluminium anodic oxide films in very different atmospheres

    Directory of Open Access Journals (Sweden)

    González, J. A.

    2003-12-01

    Full Text Available It is widely believed that the corrosion resistance behaviour of bare aluminium in natural environments is superior to that of unsealed anodised aluminium. However, results obtained in the exposure of unsealed anodised aluminium specimens with three different film thicknesses, in 9 atmospheres of Ibero-America with salinity levels between 3.9 and 517 mg.m-2.d-1 chloride, clearly shows the reverse to be true. After a sufficient time, which is shorter the higher the precipitation rate and the environmental relative humidity, a self-sealing process takes place, leading to coatings that surpass the quality standards demanded in industrial practice. Anodic films, sealed and unsealed, are protective coatings whose quality improves with ageing in most natural environments.

    Está muy difundida la idea de que el comportamiento del aluminio es superior al del aluminio anodizado y sin sellar, desde el punto de vista de la resistencia a la corrosión, en los ambientes naturales. Sin embargo, los resultados obtenidos en la exposición de anodizados sin sellar, de tres espesores diferentes, a 9 atmósferas de Iberoamérica, con salinidades comprendidas entre 3,9 y 517 mg.m-2.d-1 de cloruros, muestran, sin lugar a dudas, lo contrario. Con tiempo suficiente, tanto más rápidamente cuanto mayor sean las precipitaciones y la humedad relativa ambiental, tiene lugar un proceso de autosellado que conduce a recubrimientos que superan las normas de calidad exigidas en la práctica industrial. Los anodizados, sellados y sin sellar, son recubrimientos protectores que mejoran su calidad, en la mayoría de los ambientes naturales, con el envejecimiento.

  8. FIB-SEM investigation of trapped intermetallic particles in anodic oxide films on AA1050 aluminium

    DEFF Research Database (Denmark)

    Jariyaboon, Manthana; Møller, Per; Dunin-Borkowski, Rafal E.;

    2011-01-01

    using focused ion beam-scanning electron microscopy (FIB-SEM), SEM, and EDX. Findings - The intermetallic particles in the substrate material consisted of Fe or both Fe and Si with two different structures: irregular and round shaped. FIB-SEM cross-sectioned images revealed that the irregular....../Si ratio of the intermetallic particles decreased after anodizing. Originality/value - This paper shows that dual beam FIB-SEM seems to be an easy, less time consuming and useful method to characterize the cross-sectioned intermetallic particles incorporated in anodic film on aluminium....

  9. Nano structured porous anodized aluminium oxide by using C2H2O4 for electronic applications: Study of the cell potential effects on formation of porous alumina

    International Nuclear Information System (INIS)

    In this research, a nano porous anodized aluminium oxide AAO thin film was successfully grown onto oxide layer on silicon substrate. The anodization of Si/ SiO2/ Al substrate was conducted in a vigorous stirring oxalic acid bath solution. The rate of growth, morphology and also the kinetic study of the AAO thin film were investigated. The resulting array, pores structure and pores density of AAO strongly depends on an applied voltage of the anodizing process. (author)

  10. Trophic transfer potential of aluminium oxide nanoparticles using representative primary producer (Chlorella ellipsoides) and a primary consumer (Ceriodaphnia dubia)

    International Nuclear Information System (INIS)

    Highlights: • Trophic transfer of alumina nanoparticles using Chlorella ellipsoides and Ceriodaphnia dubia. • Subtle alterations in the feeding behaviour of the daphnids. • Disruption the energy flow through the food chain. • Transmission electron microscopy validated the disrupted feeding behaviour. - Abstract: The transfer of nanoparticles through the food chain can lead to bioaccumulation and biomagnification resulting in a long term negative impact on the ecosystem functions. The primary objective of this study was evaluation of aluminium oxide nanoparticles transfer from primary producers to primary consumers. A simple set up consisting of a primary producer (Chlorella ellipsoides) and a primary consumer (Ceriodaphnia dubia) was used. Here, C. ellipsoides were exposed to the varying concentrations of the nanoparticles ranging from 20 to 120 μg/mL (196 to 1176 μM) for 48 h and the infested algal cells were used as the feed to C. dubia. The bioaccumulation of the nanoparticles into the daphnids was noted and the biomagnification factors were computed. The exposure was noted to cause subtle alterations in the feeding behaviour of the daphnids. This might have long term consequences in the energy flow through the food chain. The reproductive behaviour of the daphnids remained unaffected upon exposure to nanoparticle infested algal feed. Distinct observations at ultra-structural scale using transmission electron microscopy provided visual evidences for the disrupted feeding behaviour upon exposure to nanoparticle treated algae. Internalization of nanoparticle like inclusion bodies in the intracellular space of algae was also detected. The findings were further substantiated by a detailed analysis of hydrodynamic stability, bioavailability and dissolution of ions from the nanoparticles over the exposure period. Altogether, the study brings out the first of its kind of observation of trophic transfer potential/behaviour of aluminium oxide nanoparticles and

  11. Trophic transfer potential of aluminium oxide nanoparticles using representative primary producer (Chlorella ellipsoides) and a primary consumer (Ceriodaphnia dubia)

    Energy Technology Data Exchange (ETDEWEB)

    Pakrashi, Sunandan; Dalai, Swayamprava; Chandrasekaran, Natarajan; Mukherjee, Amitava, E-mail: amit.mookerjea@gmail.com

    2014-07-01

    Highlights: • Trophic transfer of alumina nanoparticles using Chlorella ellipsoides and Ceriodaphnia dubia. • Subtle alterations in the feeding behaviour of the daphnids. • Disruption the energy flow through the food chain. • Transmission electron microscopy validated the disrupted feeding behaviour. - Abstract: The transfer of nanoparticles through the food chain can lead to bioaccumulation and biomagnification resulting in a long term negative impact on the ecosystem functions. The primary objective of this study was evaluation of aluminium oxide nanoparticles transfer from primary producers to primary consumers. A simple set up consisting of a primary producer (Chlorella ellipsoides) and a primary consumer (Ceriodaphnia dubia) was used. Here, C. ellipsoides were exposed to the varying concentrations of the nanoparticles ranging from 20 to 120 μg/mL (196 to 1176 μM) for 48 h and the infested algal cells were used as the feed to C. dubia. The bioaccumulation of the nanoparticles into the daphnids was noted and the biomagnification factors were computed. The exposure was noted to cause subtle alterations in the feeding behaviour of the daphnids. This might have long term consequences in the energy flow through the food chain. The reproductive behaviour of the daphnids remained unaffected upon exposure to nanoparticle infested algal feed. Distinct observations at ultra-structural scale using transmission electron microscopy provided visual evidences for the disrupted feeding behaviour upon exposure to nanoparticle treated algae. Internalization of nanoparticle like inclusion bodies in the intracellular space of algae was also detected. The findings were further substantiated by a detailed analysis of hydrodynamic stability, bioavailability and dissolution of ions from the nanoparticles over the exposure period. Altogether, the study brings out the first of its kind of observation of trophic transfer potential/behaviour of aluminium oxide nanoparticles and

  12. Application of phosphating techniques to aluminium and carbon steel surfaces using nitro guanidine as oxidizing agent

    International Nuclear Information System (INIS)

    Phosphate coatings are inorganic crystalline deposits laid down uniformly on properly prepared surfaces by a chemical reaction with the treated base metal. The reaction consists in dissolving some surface metal by acid attack and then causing surface neutralization of the phosphate solution with consequent precipitation of the phosphate coating. Phosphate coatings do not provide appreciable corrosion protection in themselves. They are useful mainly as a base for paints, ensuring good adherence of paint to steel and decreasing the tendency for corrosion to under cut the paint film at scratches or other defects. In this work firstly were realized phosphate on standard carbon steel, employing technical of cold phosphate (at 40 Centigrade degrees and with a treatment time of 30 minutes) and hot phosphate (at 88 Centigrade degrees and with a treatment time of 15 minutes), where with this last were obtained the best results. Both methods used phosphate solutions of Zn/Mn and using as catalyst Nitro guanidine. Aluminium surfaces were phosphate used solutions of Cr and as catalyst Sodium bi fluoride. The phosphating on this surface were realized at temperature of 50 Centigrade degrees and with a treatment time of 10 minutes. In this work were obtained a new phosphate coatings on steel surfaces, these coatings were realized with a phosphate solution manufactured with the precipitates gathered during the hot phosphating on carbon steel. These coatings show excellent physical characteristics and of corrosion resistance. Were determined the physical testings of the coatings phosphate obtained on carbon steel and aluminium surfaces. These testing were: roughness, thickness, microhardness and adhesion. The best results were showed in carbon steel phosphate with precipitated solutions. The technical of analysis for activation with thermic neutrons was used to determine the phosphate coatings composition. Finally, corrosion testings were realized by means of two methods

  13. Enhanced electrical and optical properties of room temperature deposited Aluminium doped Zinc Oxide (AZO) thin films by excimer laser annealing

    Science.gov (United States)

    El hamali, S. O.; Cranton, W. M.; Kalfagiannis, N.; Hou, X.; Ranson, R.; Koutsogeorgis, D. C.

    2016-05-01

    High quality transparent conductive oxides (TCOs) often require a high thermal budget fabrication process. In this study, Excimer Laser Annealing (ELA) at a wavelength of 248 nm has been explored as a processing mechanism to facilitate low thermal budget fabrication of high quality aluminium doped zinc oxide (AZO) thin films. 180 nm thick AZO films were prepared by radio frequency magnetron sputtering at room temperature on fused silica substrates. The effects of the applied RF power and the sputtering pressure on the outcome of ELA at different laser energy densities and number of pulses have been investigated. AZO films deposited with no intentional heating at 180 W, and at 2 mTorr of 0.2% oxygen in argon were selected as the optimum as-deposited films in this work, with a resistivity of 1×10-3 Ω.cm, and an average visible transmission of 85%. ELA was found to result in noticeably reduced resistivity of 5×10-4 Ω.cm, and enhancing the average visible transmission to 90% when AZO is processed with 5 pulses at 125 mJ/cm2. Therefore, the combination of RF magnetron sputtering and ELA, both low thermal budget and scalable techniques, can provide a viable fabrication route of high quality AZO films for use as transparent electrodes.

  14. PREPARATION OF ALUMINIUM OXIDE CERAMIC-CURVED PIPE BY SLIP CASTING%注浆成型法制备氧化铝陶瓷弯管

    Institute of Scientific and Technical Information of China (English)

    伍协; 陈振华; 李富营

    2011-01-01

    以氧化铝为主要原料,采用注浆成型法制备氧化铝陶瓷弯管。论文比较详细地研究了pH值、颗粒级配和有机粘结剂对产品性能的影响。结果表明:当pH值为1,粘结剂为2wt%获得的泥浆粘度最小;用颗粒大小4μm的100%α-Al2O3细粉制备的氧化铝陶瓷弯管气孔率最小、表观密度最大、显微结构最理想。%Based on aluminium oxide as main raw material, aluminium oxide ceramic-curved pipe was prepared by slip casting, pH, particle grading and binder were reshearched on the performance of aluminium oxide ceramic-curved pipe in detail.The results showed that. When the pH is 1 and binder is 2wt%, the viscosity of mud is smallest. The particle grading is 4 μ m 100% a-Al2O3 powder which porosity is the smallest, apparent density is the biggest, the microstructure is the most ideal.

  15. Computational prediction of the refinement of oxide agglomerates in a physical conditioning process for molten aluminium alloy

    Science.gov (United States)

    Tong, M.; Jagarlapudi, S. C.; Patel, J. B.; Stone, I. C.; Fan, Z.; Browne, D. J.

    2015-06-01

    Physically conditioning molten scrap aluminium alloys using high shear processing (HSP) was recently found to be a promising technology for purification of contaminated alloys. HSP refines the solid oxide agglomerates in molten alloys, so that they can act as sites for the nucleation of Fe-rich intermetallic phases which can subsequently be removed by the downstream de-drossing process. In this paper, a computational modelling for predicting the evolution of size of oxide clusters during HSP is presented. We used CFD to predict the macroscopic flow features of the melt, and the resultant field predictions of temperature and melt shear rate were transferred to a population balance model (PBM) as its key inputs. The PBM is a macroscopic model that formulates the microscopic agglomeration and breakage of a population of a dispersed phase. Although it has been widely used to study conventional deoxidation of liquid metal, this is the first time that PBM has been used to simulate the melt conditioning process within a rotor/stator HSP device. We employed a method which discretizes the continuous profile of size of the dispersed phase into a collection of discrete bins of size, to solve the governing population balance equation for the size of agglomerates. A finite volume method was used to solve the continuity equation, the energy equation and the momentum equation. The overall computation was implemented mainly using the FLUENT module of ANSYS. The simulations showed that there is a relatively high melt shear rate between the stator and sweeping tips of the rotor blades. This high shear rate leads directly to significant fragmentation of the initially large oxide aggregates. Because the process of agglomeration is significantly slower than the breakage processes at the beginning of HSP, the mean size of oxide clusters decreases very rapidly. As the process of agglomeration gradually balances the process of breakage, the mean size of oxide clusters converges to a

  16. Structure and tensile/wear properties of microarc oxidation ceramic coatings on aluminium alloy

    Institute of Scientific and Technical Information of China (English)

    魏同波; 阎逢元; 刘维民; 田军

    2004-01-01

    Thick and hard ceramic coatings were prepared on the Al-Cu-Mg alloy by microarc oxidation in alkali-silicate electrolytic solution. The thickness and microhardness of the oxide coatings were measured. The influence of current density on the growth rate of the coating was examined. The microstructure and phase composition of the coatings were investigated by means of scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. Moreover, the tensile strength of the Al alloy before and after microarc oxidation treatment were tested,and the fractography and morphology of the oxide coatings were observed using scanning electron microscope. It is found that the current density considerably influences the growth rate of the microarc oxidation coatings. The oxide coating is mainly composed of α-Al2 O3 and γ-Al2 O3, while high content of Si is observed in the superficial layer of the coating. The cross-section microhardness of 120 μm thick coating reaches the maximum at distance of 35 μm from the substrate/coating interface. The tensile strength and elongation of the coated Al alloy significantly decrease with increasing coating thickness. The microarc oxidation coatings greatly improve the wear resistance of Al alloy,but have high friction coefficient which changes in the range of 0.7 - 0.8. Under grease lubricating, friction coefficient is only 0.15 and wear loss is less than 1/10 of the loss under dry friction.

  17. Comparative study of highly dense aluminium- and gallium-doped zinc oxide transparent conducting sol–gel thin films

    Indian Academy of Sciences (India)

    Naji Al Dahoudi

    2014-10-01

    Transparent conducting aluminium- and gallium-doped zinc oxide (AZO and GZO) layers have been deposited by spin coating on glass substrates. The coatings have been sintered in air at 450 °C for 30 min and then post-annealed at 350 °C in a reducing atmosphere for 30 min. The electrical, optical and morphological properties of both coatings have been studied and compared. The conventional sols lead to very thin coating, typically 24 nm for a single layer of AZO and 32 nm of GZO with electrical resistivity of 0.72 and 0.35 cm, respectively. The value however, drastically decreases down to a minimum of 2.6 × 10-2 cm for AZO and 1.76 × 10-2 cm for GZO, when five multilayer coatings are made. The origin of these differences is due to the different morphology of the coatings showing different electron scattering process. The GZO sol leads to denser smoother structure (porosity of 5%) layers with an average roughness of 2.76 Å, while the AZO coating is formed by a more porous assembly (porosity of 20%) with an average roughness of 3.46 Å. Both coatings exhibit high transparency ( > 85%) in the visible spectrum range with a slight shift of the absorption energy gap.

  18. A Macroporous TiO2 Oxygen Sensor Fabricated Using Anodic Aluminium Oxide as an Etching Mask

    Directory of Open Access Journals (Sweden)

    Sheng-Po Wu

    2010-01-01

    Full Text Available An innovative fabrication method to produce a macroporous Si surface by employing an anodic aluminium oxide (AAO nanopore array layer as an etching template is presented. Combining AAO with a reactive ion etching (RIE processes, a homogeneous and macroporous silicon surface can be effectively configured by modulating AAO process parameters and alumina film thickness, thus hopefully replacing conventional photolithography and electrochemical etch methods. The hybrid process integration is considered fully CMOS compatible thanks to the low-temperature AAO and CMOS processes. The gas-sensing characteristics of 50 nm TiO2 nanofilms deposited on the macroporous surface are compared with those of conventional plain (or non-porous nanofilms to verify reduced response noise and improved sensitivity as a result of their macroporosity. Our experimental results reveal that macroporous geometry of the TiO2 chemoresistive gas sensor demonstrates 2-fold higher (~33% improved sensitivity than a non-porous sensor at different levels of oxygen exposure. In addition, the macroporous device exhibits excellent discrimination capability and significantly lessened response noise at 500 °C. Experimental results indicate that the hybrid process of such miniature and macroporous devices are compatible as well as applicable to integrated next generation bio-chemical sensors.

  19. Development of electrostatic supercapacitors by atomic layer deposition on nanoporous anodic aluminium oxides for energy harvesting applications

    Directory of Open Access Journals (Sweden)

    Lucia eIglesias

    2015-03-01

    Full Text Available Nanomaterials can provide innovative solutions for solving the usual energy harvesting and storage drawbacks that take place in conventional energy storage devices based on batteries or electrolytic capacitors, because they are not fully capable for attending the fast energy demands and high power densities required in many of present applications. Here, we report on the development and characterization of novel electrostatic supercapacitors made by conformal Atomic Layer Deposition on the high open surface of nanoporous anodic alumina membranes employed as templates. The structure of the designed electrostatic supercapacitor prototype consists of successive layers of Aluminium doped Zinc Oxide, as the bottom and top electrodes, together Al2O3 as the intermediate dielectric layer. The conformality of the deposited conductive and dielectric layers, together with their composition and crystalline structure have been checked by XRD and electron microscopy techniques. Impedance measurements performed for the optimized electrostatic supercapacitor device give a high capacitance value of 200 µF/cm2 at the frequency of 40 Hz, which confirms the theoretical estimations for such kind of prototypes, and the leakage current reaches values around of 1.8 mA/cm2 at 1 V. The high capacitance value achieved by the supercapacitor prototype together its small size turns these devices in outstanding candidates for using in energy harvesting and storage applications.

  20. 表面处理对5083铝合金板胶接性能的影响%Effects of Surface Treatment on Adhesion Strength of 5083 Aluminium Alloy Plates

    Institute of Scientific and Technical Information of China (English)

    刘晓静; 陈春焕; 赵志强

    2013-01-01

    以α-氰基丙烯酸酯类瞬干胶为胶粘剂,采用剪切试验、接触角试验和扫描电镜观察系统研究了丙酮简单清洗、喷砂处理、阳极氧化处理以及偶联剂处理对5083铝合金板胶接接头剪切强度的影响.结果表明:经简单清洗后,所得胶接接头的剪切强度最低;在附着力和机械啮合的共同作用下,喷砂处理和阳极氧化处理胶接接头的强度得到了提高,其中阳极氧化处理的效果最为明显,与简单清洗胶接接头相比,剪切强度提高了223.1%;胶接前适当使用偶联剂可以使简单清洗和喷砂处理胶接接头的剪切强度提高,在该试验条件下,KH-550偶联剂体积分数为5%时,胶接接头的剪切强度均达到了最大值;但偶联剂使阳极氧化处理形成的纳米小孔不能发挥机械啮合作用,所得胶接接头的剪切强度相比未使用偶联剂的反而降低.%Using crcyanoaerylate as adhesive, the effect of surface treatments such as simple cleaning, sand blasting, anodic oxidation and coupling agent treatment on adhesion strength of 5083 aluminium alloy plates was studied by shearing test, contact angle test and SEM observation. The results indicate that through simple cleaning, the shear strength of the adhesive joints was the lowest. With the combined function of adhesive force and mechanical meshing, the shear strength of the adhesive joints which pretreated by sand blasting and anodic oxidation was increased, the effect of anodic oxidation treatment was the most obvious, and the shear strength of joints pretreated by anodic oxidation increased 223. 1% than that of joints pretreated by simple cleaning. Proper using of coupling agent before adhesion resulted in the improvement of shear strength of joints pretreated by simple cleaning and sand blasting. Under this test condition, the proper volume fraction of KH-550 coupling agent was 5%, and bonding with which the shear strength of the joints got to the highest

  1. Hysteretic Process of Aluminium Oxide Films Deposited by Reactive Sputtering Method%磁控溅射沉积氧化铝薄膜的迟滞效应

    Institute of Scientific and Technical Information of China (English)

    徐化冰; 徐香坤

    2013-01-01

    The hysteretic behaviour of aluminium oxide films in reactive sputtering was investigated by plasma optical emission spectroscopy technology. The evolutions of aluminium( 396 nm) and aluminium oxide(484 nm) emission lines as functions of oxygen flow rates were measured. The crystal structure, a-tomic ratio and light transmission of aluminium oxide films were analyzed by X-ray diffraction (XRD) , energy dispersive spectrometer (EDS) and ultraviolet - visible spectroscopy (UV-VIS). The results show that because the aluminium oxide deposited on the magnetron target impacts the alumina sputtering, the Al (39 6 nm) line intensity affects the crystal structure, atomic ratio and light transmission of aluminium oxide films. Meanwhile, the hysteresis curves show that an optimum deposition zone exists in the transition region where the oxygen flow rates is 1. 5~2. 0 mL/min. The sample obtains in this deposition zone' and its composition has the best chemical atomic weight ratio of 0. 689. This indicates that the deposited aluminium oxide films have excellent qualities.%利用光发射谱(OES)技术,对反应磁控溅射过程的氧化铝薄膜的迟滞效应进行了研究.对等离子体中的铝(396 nm)谱线和氧化铝(484 nm)谱线随氧气流量的变化进行了实时测量,获得了其迟滞曲线.在迟滞曲线的不同位置分别进行了氧化铝薄膜的沉积试验.采用X射线衍射仪(XRD)、能谱仪(EDS)和紫外可见吸收光谱仪(UV-VIS)对薄膜的晶体结构、成分和透光性进行了分析.结果表明:由于磁控靶表面的氧化铝沉积影响了铝靶材的溅射,导致Al(396 nm)谱线的强度对氧化铝薄膜的晶体结构、原子比以及样品的透光性有明显的影响.同时,由迟滞曲线可知在氧气流量为1.5~2.0 mL/min的过渡区内存在着一个最优沉积带.在这个沉积带获得的样品,其成分具有最佳的化学原子量配比,为0.689.这说明沉积出了高质量的氧化铝薄膜.

  2. Effect of Oxide Inclusions on Electrochemical Properties of Aluminium Sacrificial Anodes

    Institute of Scientific and Technical Information of China (English)

    M. Emamy; A. Keyvani; M. Mahta; J. Campbell

    2009-01-01

    Oxide films are incorporated into melts by an entrainment process, and are expected to be present in most metals, but particularly cast Al alloys. The oxides are necessarily present as folded-over double films (bifilms) that are effectively cracks. Their effect on the electrochemical behaviour of cast Al-5Zn-0.02ln sacrificial anodes was studied in 3 wt pct sodium chloride solution using the NACE efficiency evaluation. Three methods were employed to entrain progressive amounts of oxide in the alloy, including the addition of Al-Zn-ln maching chips to the charge, increasing the pouring height, and agitating the melt. The introduction of oxide bifilms in the cast alloy resulted in the deterioration of the electrochemical properties of the sacrificial anodes, such as current capacity and anode efficiency, and introduced increasing variability in these properties. The results suggest that corrosion behaviour is strongly related to the presence of bifilms suspended in the liquid alloy because bifilms provide crack paths allowing the corrodant to penetrate deeply into the metal matrix, and simultaneously provide localized galvanic cells because of the precipitation of Fe rich intermetallic compounds on their outer surfaces.

  3. Comparative study of the cytotoxic and genotoxic effects of titanium oxide and aluminium oxide nanoparticles in Chinese hamster ovary (CHO-K1) cells

    International Nuclear Information System (INIS)

    The aim of this study was to analyze the cytotoxicity and genotoxicity of titanium oxide (TiO2) and aluminium oxide (Al2O3) nanoparticles (NPs) on Chinese hamster ovary (CHO-K1) cells using neutral red (NR), mitochondrial activity (by MTT assay), sister chromatid exchange (SCE), micronucleus (MN) formation, and cell cycle kinetics techniques. Results showed a dose-related cytotoxic effect evidenced after 24 h by changes in lysosomal and mitochondrial dehydrogenase activity. Interestingly, transmission electronic microscopy (TEM) showed the formation of perinuclear vesicles in CHO-K1 cells after treatment with both NPs during 24 h but no NP was detected in the nuclei. Genotoxic effects were shown by MN frequencies which significantly increased at 0.5 and 1 μg/mL TiO2 and 0.5-10 μg/mL Al2O3. SCE frequencies were higher for cells treated with 1-5 μg/mL TiO2. The absence of metaphases evidenced cytotoxicity for higher concentrations of TiO2. No SCE induction was achieved after treatment with 1-25 μg/mL Al2O3. In conclusion, findings showed cytotoxic and genotoxic effects of TiO2 and Al2O3 NPs on CHO-K1 cells. Possible causes of controversial reports are discussed further on.

  4. Effect of electrolyte temperature on the thickness of anodic aluminium oxide (AAO layer

    Directory of Open Access Journals (Sweden)

    P. Michal

    2016-07-01

    Full Text Available Effect of electrolyte temperature on the thickness of resulting oxide layer has been studied. Unlike previous published studies this article was aimed to monitor the relationship between electrolyte temperature and resulting AAO layer thickness in interaction with other input factors affecting during anodizing process under special process condition, i.e. lower concentration of sulphuric acid, oxalic acid, boric acid and sodium chloride. According to Design of Experiments (DOE 80 individual test runs of experiment were carried out. Using statistical analysis and artificial intelligence for evaluation, the computational model predicting the thickness of oxide layer in the range from 5 / μm to 15 / μm with tolerance ± 0,5 / μm was developed.

  5. Assessment of the biological effects of welding fumes emitted from metal inert gas welding processes of aluminium and zinc-plated materials in humans.

    Science.gov (United States)

    Hartmann, L; Bauer, M; Bertram, J; Gube, M; Lenz, K; Reisgen, U; Schettgen, T; Kraus, T; Brand, P

    2014-03-01

    The aim of this study was to investigate biological effects and potential health risks due to two different metal-inert-gas (MIG) welding fumes (MIG welding of aluminium and MIG soldering of zinc coated steel) in healthy humans. In a threefold cross-over design study 12 male subjects were exposed to three different exposure scenarios. Exposures were performed under controlled conditions in the Aachener Workplace Simulation Laboratory (AWSL). On three different days the subjects were either exposed to filtered ambient air, to welding fumes from MIG welding of aluminium, or to fumes from MIG soldering of zinc coated materials. Exposure was performed for 6 h and the average fume concentration was 2.5 mg m(-3). Before, directly after, 1 day after, and 7 days after exposure spirometric and impulse oscillometric measurements were performed, exhaled breath condensate (EBC) was collected and blood samples were taken and analyzed for inflammatory markers. During MIG welding of aluminium high ozone concentrations (up to 250 μg m(-3)) were observed, whereas ozone was negligible for MIG soldering. For MIG soldering, concentrations of high-sensitivity CRP (hsCRP) and factor VIII were significantly increased but remained mostly within the normal range. The concentration of neutrophils increased in tendency. For MIG welding of aluminium, the lung function showed significant decreases in Peak Expiratory Flow (PEF) and Mean Expiratory Flow at 75% vital capacity (MEF 75) 7 days after exposure. The concentration of ristocetin cofactor was increased. The observed increase of hsCRP during MIG-soldering can be understood as an indicator for asymptomatic systemic inflammation probably due to zinc (zinc concentration 1.5 mg m(-3)). The change in lung function observed after MIG welding of aluminium may be attributed to ozone inhalation, although the late response (7 days after exposure) is surprising.

  6. Anticorrosion properties of tin oxide coatings for carbonaceous bipolar plates of proton exchange membrane fuel cells

    Science.gov (United States)

    Kinumoto, Taro; Nagano, Keita; Yamamoto, Yuji; Tsumura, Tomoki; Toyoda, Masahiro

    2014-03-01

    An anticorrosive surface treatment of a carbonaceous bipolar plate used in proton exchange membrane fuel cells (PEMFCs) was demonstrated by addition of a tin oxide surface coating by liquid phase deposition (LPD), and its effectiveness toward corrosion prevention was determined. The tin oxide coating was deposited by immersion in tin fluoride and boric acid solutions, without any observable decrease in the bipolar plate electrical conductivity. Anticorrosion properties of a flat carbonaceous bipolar plate were investigated in an aqueous HClO4 electrolyte solution (10 μmol dm-3) at 80 °C. CO2 release due to corrosion was significant for the bare specimen above 1.3 V, whereas no CO2 release was noted for the tin-oxide-coated specimen, even approaching 1.5 V. Moreover, minimal changes in contact angle against a water droplet before and after treatment indicated suppressed corrosion of the surface-coated specimen. Anticorrosion properties were also confirmed for a model bipolar plate having four gas flow channels. The tin oxide layer remained on the channel surfaces (inner walls, corners and intersections) after durability tests. Based on these results, tin-oxide-based surface coatings fabricated by LPD show promise as an anticorrosion technique for carbonaceous bipolar plates for PEMFCs.

  7. The stability of aluminium oxide monolayer and its interface with two-dimensional materials.

    Science.gov (United States)

    Song, Ting Ting; Yang, Ming; Chai, Jian Wei; Callsen, Martin; Zhou, Jun; Yang, Tong; Zhang, Zheng; Pan, Ji Sheng; Chi, Dong Zhi; Feng, Yuan Ping; Wang, Shi Jie

    2016-01-01

    The miniaturization of future electronic devices requires the knowledge of interfacial properties between two-dimensional channel materials and high-κ dielectrics in the limit of one atomic layer thickness. In this report, by combining particle-swarm optimization method with first-principles calculations, we present a detailed study of structural, electronic, mechanical, and dielectric properties of Al2O3 monolayer. We predict that planar Al2O3 monolayer is globally stable with a direct band gap of 5.99 eV and thermal stability up to 1100 K. The stability of this high-κ oxide monolayer can be enhanced by substrates such as graphene, for which the interfacial interaction is found to be weak. The band offsets between the Al2O3 monolayer and graphene are large enough for electronic applications. Our results not only predict a stable high-κ oxide monolayer, but also improve the understanding of interfacial properties between a high-κ dielectric monolayer and two-dimensional material. PMID:27381580

  8. Preliminary results on TL and OSL aluminium oxide dosimeters developed at IPEN

    Energy Technology Data Exchange (ETDEWEB)

    Fukumori, David T.; Yoshito, Walter K.; Ussui, Valter; Lazar, Dolores R.R.; Campos, Leticia L., E-mail: fukumori@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The aluminum oxide composes the modern TL and OSL radiation dosimeters. TL and OSL phenomena are related to chemical elements in the crystalline structure of {alpha}-Al{sub 2}O{sub 3}. The aim of this work was to develop materials based on aluminum oxide for use in TL and OSL dosimetry. The studies included the dosimetric properties of alumina samples obtained by electro fusion, adsorption and coprecipitation. Electro fused alumina commercially available as abrasive particles was used to produce the pellets by glass sintering. Adsorption and coprecipitation were the methods used to insert metal ions to alumina. The best results were achieved with electro fused alumina and Tm{sup 3+} doped Al{sub 2}O{sub 3} pellets. The electro fused alumina-glass pellets show TL and OSL signals and the TL curve has two peaks. Its minimum detectable radiation dose is 7.2 mGy and the linearity of TL response as function of dose is up to about 800 mGy. The {alpha}-Al{sub 2}O{sub 3}:Tm pellets produced by sintering at 1550 deg C presented a meaningful TL glow curve so that it is worth studying their properties and viability of use in dosimetry. (author)

  9. The stability of aluminium oxide monolayer and its interface with two-dimensional materials

    Science.gov (United States)

    Song, Ting Ting; Yang, Ming; Chai, Jian Wei; Callsen, Martin; Zhou, Jun; Yang, Tong; Zhang, Zheng; Pan, Ji Sheng; Chi, Dong Zhi; Feng, Yuan Ping; Wang, Shi Jie

    2016-07-01

    The miniaturization of future electronic devices requires the knowledge of interfacial properties between two-dimensional channel materials and high-κ dielectrics in the limit of one atomic layer thickness. In this report, by combining particle-swarm optimization method with first-principles calculations, we present a detailed study of structural, electronic, mechanical, and dielectric properties of Al2O3 monolayer. We predict that planar Al2O3 monolayer is globally stable with a direct band gap of 5.99 eV and thermal stability up to 1100 K. The stability of this high-κ oxide monolayer can be enhanced by substrates such as graphene, for which the interfacial interaction is found to be weak. The band offsets between the Al2O3 monolayer and graphene are large enough for electronic applications. Our results not only predict a stable high-κ oxide monolayer, but also improve the understanding of interfacial properties between a high-κ dielectric monolayer and two-dimensional material.

  10. Development and characterization of ultra-thin dosemeters of aluminium oxide; Desarrollo y caracterizacion de dosimetros ultra-delgados de oxido de aluminio

    Energy Technology Data Exchange (ETDEWEB)

    Villagran V, E

    2003-07-01

    The aim of the present thesis work has been to investigate the thermoluminescent (Tl) response of aluminium oxide thin films with thicknesses of the order of 300 nm prepared by laser ablation. Aluminium oxide thin films show Tl response after they are subject to ultraviolet, beta and gamma radiation. The Tl curves exhibit peaks around 75 C and 169 C for UV radiation, 112 C and 180 C for beta particles and 110 C and 176 C for gamma radiation. In order to improve the Tl response some growth parameters such as power density and distance target-substrate were varied. The relation dose-response shows a non-linear behavior for UV irradiation; a linear behavior for beta-particles dose from 150 mGy to 50 Gy, and a linear behavior for gamma radiation dose from 5 Gy to 100 Gy. The kinetic Tl parameters were determined by Computerized Glow Curve Deconvolution (CGCD) method as well as using analytical methods. The CGCD results show that the high temperature peak is composed by four peaks with maximums in 165.7, 188.1, 215.3, 246.5 C. These obey a second order kinetics. The trap depth (E) values are 1.4, 1.6, 1.8 and 2.0 eV respectively. The different analytical results show a trap depth values of 0.914, 0.82 and 0.656 eV respectively. Oxide aluminium thin films obtained would be a suitable tool owing to their potential applications in clinical dosimetry, in the dose distributions due to weekly penetrating radiation determination, and in interfaces dosimetry. (Author)

  11. Potentiostatic Electrochemical Preparation and Characterisation of Aluminium Containing Nickel Selenide

    Directory of Open Access Journals (Sweden)

    Sandeep Gohar

    2014-01-01

    Full Text Available The wide range of properties exhibited by Al based alloy makes them suitable for different applications. Aluminium containing nickel Selenide ternary alloy possess considerable corrosion resistance as compared to their pure metal counterparts. The objective of the present work has been focused on the preparation and characterisation of its thin film. Alloying with Aluminium improve the oxidation resistance and increases the heat conductivity of the alloy. There is always a high demand for plating Al and its alloys in automotive and aerospace products, house-hold goods, and artificial jewellery etc,. The morphological and the structural studies of the electrodeposited thin film were determined by Scanning Electron Microscope (SEM images and X-Ray Diffraction Pattern (XRD while elemental composition has been done by Energy Dispersive X-Ray Spectroscopy (EDAX analysis.

  12. PLATE

    DEFF Research Database (Denmark)

    Kling, Joyce; Hjulmand, Lise-Lotte

    2008-01-01

    Project in Language Assessment for Teaching in English (PLATE) language professionals from CBS’s Language Center observe teachers and provide feedback using evaluation criteria from the Common European Framework for Reference (CEFR) supplemented by some additional criteria which take the LSP nature of......Copenhagen Business School (CBS) finds itself needing to address the issue of English-medium instruction for its increasing number of foreign exchange and full degree students. With internationalisation as a main pillar of the institution’s agenda, there are concerns whether the teaching faculty......’s level of English is sufficient for the increasing number of courses offered in English each semester. This paper addresses these concerns and describes a pilot project initiated in 2003 at CBS to gauge the overall English language proficiency of those teaching content courses in English. Through the...

  13. Spectroscopic study of plasma during electrolytic oxidation of magnesium- and aluminium-alloy

    Science.gov (United States)

    Jovović, J.; Stojadinović, S.; Šišović, N. M.; Konjević, N.

    2012-10-01

    We present the results of an optical emission spectroscopy study of Plasma during Electrolytic Oxidation (PEO) of magnesium- and aluminum-alloy. Plasma electron number density Ne diagnostics is performed either from the Hβ line shape or from the width or shift of non-hydrogenic ion lines of aluminum and magnesium. The line profile analysis of the Hβ suggests presence of two PEO processes characterized by relatively low electron number densities Ne≈1.2×1015 cm-3 and Ne≈2.3×1016 cm-3. Apart from these two low Ne processes, there is the third one related to the ejection of evaporated anode material through micro-discharge channels. This process is characterized by larger electron density Ne=(1.2-1.6)1017 cm-3, which is detected from the shape and shift of aluminum and magnesium singly charged ion lines. Two low Ne values detected from the Hβ and large Ne measured from the widths and shift of ion lines suggest presence of three types of discharges during PEO with aluminum- and magnesium-alloy anode. On the basis of present and earlier results one can conclude that low Ne processes do not depend upon anode material or electrolyte composition.The electron temperature of 4000 K and 33,000 K are determined from relative intensities of Mg I and O II lines, respectively. The attention is drawn to the possibility of Ne application for Te evaluation using Saha equation what is of importance for PEO metal plasma characterization. During the course of this study, difficulties in the analysis of spectral line shapes are encountered and the ways to overcome some of the obstacles are demonstrated.

  14. INTEROGATION OF THE MANUFACTURING ROUTE OF ALUMINIUM AA 1050 USED IN LITHOGRAPHIC APPLICATION

    OpenAIRE

    Witkowska, Malgorzata Danuta

    2013-01-01

    The aluminium AA1050 alloy, known as commercially pure aluminium, contains 99.5% Al, together with Fe and Si as major alloying elements. During fabrication of aluminium substrates for lithographic printing plates in Bridgnorth Aluminium Ltd, the AA 1050 aluminium alloy proceeds through various stages of thermomechanical processing, with the conditions at each processing stage influencing the microstructure of the final coil. Because of its specific gravity, tensile strength, surface performa...

  15. Comparative study of the cytotoxic and genotoxic effects of titanium oxide and aluminium oxide nanoparticles in Chinese hamster ovary (CHO-K1) cells

    Energy Technology Data Exchange (ETDEWEB)

    Di Virgilio, A.L. [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA), Diag. 113 y 64, Correo 16, Suc. 4, La Plata (1900) (Argentina); Reigosa, M. [Instituto Multidisciplinario de Biologia Celular (IMBICE), Calle 526 y Camino Gral. Belgrano (entre 10 y 11), La Plata 1900 (Argentina); Arnal, P.M. [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA), Diag. 113 y 64, Correo 16, Suc. 4, La Plata 1900 (Argentina); Fernandez Lorenzo de Mele, M., E-mail: mmele@inifta.unlp.edu.ar [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA), Diag. 113 y 64, Correo 16, Suc. 4, La Plata 1900 (Argentina)

    2010-05-15

    The aim of this study was to analyze the cytotoxicity and genotoxicity of titanium oxide (TiO{sub 2}) and aluminium oxide (Al{sub 2}O{sub 3}) nanoparticles (NPs) on Chinese hamster ovary (CHO-K1) cells using neutral red (NR), mitochondrial activity (by MTT assay), sister chromatid exchange (SCE), micronucleus (MN) formation, and cell cycle kinetics techniques. Results showed a dose-related cytotoxic effect evidenced after 24 h by changes in lysosomal and mitochondrial dehydrogenase activity. Interestingly, transmission electronic microscopy (TEM) showed the formation of perinuclear vesicles in CHO-K1 cells after treatment with both NPs during 24 h but no NP was detected in the nuclei. Genotoxic effects were shown by MN frequencies which significantly increased at 0.5 and 1 {mu}g/mL TiO{sub 2} and 0.5-10 {mu}g/mL Al{sub 2}O{sub 3}. SCE frequencies were higher for cells treated with 1-5 {mu}g/mL TiO{sub 2}. The absence of metaphases evidenced cytotoxicity for higher concentrations of TiO{sub 2}. No SCE induction was achieved after treatment with 1-25 {mu}g/mL Al{sub 2}O{sub 3}. In conclusion, findings showed cytotoxic and genotoxic effects of TiO{sub 2} and Al{sub 2}O{sub 3} NPs on CHO-K1 cells. Possible causes of controversial reports are discussed further on.

  16. Automotive Aluminium Recycling

    Energy Technology Data Exchange (ETDEWEB)

    Gelas, B. des

    2000-07-01

    This paper aims at providing an overview on the contribution of aluminium recycling in the supply of new aluminium for automotive applications. Based on a presentation on how the global European automotive aluminium supply requirements are met, an analysis of the present and future contribution of automotive aluminium recycling is first presented. Current situation and future developments for automotive aluminium recycling practices are then commented, together with an outline on design principles for easier aluminium recycling. (orig.)

  17. 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....

  18. Steam generated conversion coating on aluminium alloys

    DEFF Research Database (Denmark)

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

    and growth of oxide film on different intermetallic particles and corrosion behaviour of such alloys.Surface morphology was observed by using FEG-SEM, EDX and FIB-SEM. Metal oxide surface characterization and compositional depth profiling were investigated by using XPS and GD-OES respectively......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......) depending on the preparation parameters/conditions. Moreover, with the knowledge of factors controlling film growth, composition and morphology, such oxide layers carry huge potential for practical applications. Pure aluminium (AA1090, 99.94 wt. %) and other aluminium alloy surfaces were exposed to high...

  19. Aluminium as heating fuel. Tests with aluminium powder prove suitability in principle. Aluminium als Heizungs-Brennstoff. Versuche mit Aluminiumpulver beweisen prinzipielle Eignung

    Energy Technology Data Exchange (ETDEWEB)

    Weber, R.

    1990-12-01

    Tests prove that aluminium powder is perfectly suited as fuel and storage material for solar energy. The combustion product itself is again the base material for aluminium production, i.e. aluminium can be recycled. There are three problematic areas: 1. flame stability, 2. combustion duration and 3. environmental compatibility. Further development projects will aim at the construction of practice-orientated plants in which combustion, heat extraction and recovery of aluminium oxide is combined. A further aim is the melting burner to which aluminium is supplied in form of wires, cuttings or rods. (BWI).

  20. Olive mill wastewater treatment by anodic oxidation with parallel plate electrodes.

    Science.gov (United States)

    Panizza, Marco; Cerisola, Giacomo

    2006-03-01

    Olive mill wastewater is characterized by very high chemical oxygen demand (COD) values and contains high concentrations of polyphenols that inhibit the activity of micro-organisms during biological oxidations. In this paper, the applicability of electrochemical oxidation of a real olive-mill wastewater was studied by performing galvanostatic electrolysis using parallel plate electrodes. A mixed titanium and ruthenium oxide (Ti/TiRuO2) was used as anode and stainless steel as cathode. The effect of chloride concentration and applied current on the removal of COD, aromatic content and colour was investigated. The experimental results showed that an effective electrochemical oxidation was achieved in which the wastewater was decolourised and the COD and aromatic content completely eliminated. In particular, the mineralisation took place by indirect oxidation, mediated by active chlorine, and the COD removal rate was enhanced by the addition of 5 g L(-1) of NaCl to the wastewater and by increasing the applied current. PMID:16510168

  1. 化学镀Ni-P合金在铝合金表面强化上的应用%Application of Electroless Plating Ni-P Alloy on Aluminium Alloy

    Institute of Scientific and Technical Information of China (English)

    朱晓云; 郭忠诚; 翟大成

    2001-01-01

    研究了化学镀镍-磷合金的性能,结果表明,热处理温度对镍-磷合金镀层硬度和耐磨性有较大的影响,二者经400℃×1 h热处理后达到峰值;镍-磷合金在酸、碱、盐介质中的耐蚀性优于1Cr18Ni9Ti不锈钢。应用结果证明,化学镀Ni-P合金在铝合金零部件上具有广泛的应用前景。%Properties of electroless plating Ni-Palloy have been studied, the results show that heattreatment temperature has a considerable effect onthe hardness and wear resistance of Ni-P alloy, andthey reach peak value after heat treatment at 400 ℃X 1h. Corrosion resistance of Ni-P alloy in acid,alkaline and salt media is superior to that of1Cr18Ni9Ti stainless steel. The electroless platingNi-P alloy has a wide application for the componentof aluminium alloy.

  2. 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.

  3. Aluminium structural elements

    OpenAIRE

    Švent, Nejc

    2016-01-01

    This thesis focuses on the structural analysis of aluminium structural members in accordance with the SIST EN 1999-1-1 standard. In the introduction, historical development of aluminium is summarized, as well as the processes of structural aluminium production and manufacture. Predominantly, resistance control checks of aluminium structural members are covered, with special attention to the major contrasts between aluminium and steel structural analyses. Finally, fundamental examples of resis...

  4. Enhancing low-field magnetoresistance of La0.67Ca0.33MnO3 films deposited on anodized aluminium-oxide membranes

    Institute of Scientific and Technical Information of China (English)

    Tang Wei-Hua; Li Pei-Gang; Lei Ming; Guo Yan-Feng; Chen Lei-Ming; Li Ling-Hong; Song Peng-Yun; Chen ChinPing

    2006-01-01

    In this paper we report a new method to fabricate nanostructured films.La0.67Ca0.33MnO3(LCMO)nanostructured films have been fabricated by using pulsed electron beam deposition (PED) on anodized aluminium oxide (AAO)membranes.The magnetic and electronic transport properties are investigated by using the Quantum Design physics properties measurement system (PPMS) and magnetic properties measurement system (MPMS).The resistance peak temperature (Tp) is about 85 K and the Curie temperature(Tc) is about 250 K for the LCMO film on an AAO membrane with a pore diameter of 20 nm.Large magnetoresistance ratio (MR) is observed near Tp.The MR is as high as 85 %under 1T magnetic field.The great enhancement of MR at low magnetic fields could be attributed to the lattice distortion and the grain boundary that are induced by the nanopores on the AAO membrane.

  5. The Cracking Induced by Oxidation-Hydriding in Welding Joints of Zircaloy-4 Plates

    Institute of Scientific and Technical Information of China (English)

    周邦新; 姚美意; 苗志; 李强; 刘文庆

    2003-01-01

    The welding joints of Zircaloy-4 plates obtained by diffusion welding at 800℃ under pressure in vacuum were cracked during autoclave tests at 400℃ superheated steam after exposure longer than 150 days. The section of specimens was examined by optical microscopy and the composition at the tips of cracking was analyzed by electron microprobe. The result shows that the combination of oxidation and hydriding induced cracking is responsible for this failure of the welding joints.

  6. Design and performance of tubular flat-plate solid oxide fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Matsushima, T.; Ikeda, D.; Kanagawa, H. [NTT Integrated Information & Energy Systems Labs., Tokyo (Japan)] [and others

    1996-12-31

    With the growing interest in conserving the environmental conditions, much attention is being paid to Solid Oxide Fuel Cell (SOFC), which has high energy-conversion efficiency. Many organizations have conducted studies on tubular and flat type SOFCs. Nippon Telegraph and Telephone Corporation (NTT) has studied a combined tubular flat-plate SOFC, and already presented the I-V characteristics of a single cell. Here, we report the construction of a stack of this SOFC cell and successful generation tests results.

  7. Remelting of Aluminium by Continuous Submersion of Rolled Scrap

    Energy Technology Data Exchange (ETDEWEB)

    Farner, Snorre

    2000-12-01

    When remelting aluminium scrap, metal losses due to dross generation is a common problem. Reduction of these losses will give substantial economic and environmental benefits. Dross is generated when aluminium metal oxidizes and films of oxide envelope molten metal. When a cold metal object is immersed in a melt, the heat of the melt around this is transferred so rapidly into the object that a shell of melt often solidifies to the surface of the object. When scrap with low bulk density is charged to a melt, solidification of melt on the cold scrap prevents melt from entering the cavities in the bulk of the scrap, and the bulk density remains low. Thus the scrap tends to float on the melt surface. Submersion of this scrap is important to avoid oxidation and subsequent dross generation. One solution to this is to roll scrap to a strip and feed it into the melt. This system has been examined by studying feeding of a continuous, thin aluminium plate into molten aluminium. Also, the effect of lacquer was considered, as well as feeding the plate into a launder with melt flowing along the surface of the plate. An analytical, one-dimensional, steady-state model has been developed to describe the melting and the melting mechanisms. It is based on a shell solidifying on the plate surface and a gap introducing a thermal resistance 1/h{sub g} between the shell and the plate. The thermal resistance 1/h{sub l} of the boundary layer of the melt is included. Depending on these resistances, the initial temperature of the plate and the melt temperature, a shell will form, and the plate will penetrate a distance P into the melt before it melts away. An experimental apparatus was designed and constructed to feed aluminium plate from a coil into a melt bath at a specified velocity. The plate could be withdrawn rapidly to ''freeze'' the situation like it was below the melt surface. The penetration depth P of the plate could be measured and shell formation observed

  8. Optimization of friction welding by taguchi and ANOVA method on commercial aluminium tube to Al 2025 tube plate with backing block using an external tool

    Energy Technology Data Exchange (ETDEWEB)

    Kanna, S.; Kumaraswamidhs, L. A. [Indian Institute of Technology, Dhanbad (India); Kumaran, S. Senthil [RVS School of Engineering and Technology, Dindigul (India)

    2016-05-15

    The aim of the present work is to optimize the Friction welding of tube to tube plate using an external tool (FWTPET) with clearance fit of commercial aluminum tube to Al 2025 tube plate using an external tool. Conventional frictional welding is suitable to weld only symmetrical joints either tube to tube or rod to rod but in this research with the help of external tool, the welding has been done by unsymmetrical shape of tube to tube plate also. In this investigation, the various welding parameters such as tool rotating speed (rpm), projection of tube (mm) and depth of cut (mm) are determined according to the Taguchi L9 orthogonal array. The two conditions were considered in this process to examine this experiment; where condition 1 is flat plate with plain tube Without holes [WOH] on the circumference of the surface and condition 2 is flat plate with plane tube has holes on its circumference of the surface With holes [WH]. Taguchi L9 orthogonal array was utilized to find the most significant control factors which will yield better joint strength. Besides, the most influential process parameter has been determined using statistical Analysis of variance (ANOVA). Finally, the comparison of each result has been done for conditions by means percentage of contribution and regression analysis. The general regression equation is formulated and better strength is obtained and it is validated by means of confirmation test. It was observed that value of optimal welded joint strength for both tube without holes and tube with holes are to be 319.485 MPa and 264.825 MPa, respectively.

  9. 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.

  10. Nano-oxide thin films deposited via atomic layer deposition on microchannel plates.

    Science.gov (United States)

    Yan, Baojun; Liu, Shulin; Heng, Yuekun

    2015-01-01

    Microchannel plate (MCP) as a key part is a kind of electron multiplied device applied in many scientific fields. Oxide thin films such as zinc oxide doped with aluminum oxide (ZnO:Al2O3) as conductive layer and pure aluminum oxide (Al2O3) as secondary electron emission (SEE) layer were prepared in the pores of MCP via atomic layer deposition (ALD) which is a method that can precisely control thin film thickness on a substrate with a high aspect ratio structure. In this paper, nano-oxide thin films ZnO:Al2O3 and Al2O3 were prepared onto varied kinds of substrates by ALD technique, and the morphology, element distribution, structure, and surface chemical states of samples were systematically investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoemission spectroscopy (XPS), respectively. Finally, electrical properties of an MCP device as a function of nano-oxide thin film thickness were firstly studied, and the electrical measurement results showed that the average gain of MCP was greater than 2,000 at DC 800 V with nano-oxide thin film thickness approximately 122 nm. During electrical measurement, current jitter was observed, and possible reasons were preliminarily proposed to explain the observed experimental phenomenon.

  11. A 200 V silicon-on-sapphire LDMOS structure with a step oxide extended field plate

    Science.gov (United States)

    Roig, J.; Flores, D.; Rebollo, J.; Hidalgo, S.; Millan, J.

    2004-02-01

    Fabrication of power integrated circuits on silicon-on-sapphire (SOS) substrates has rarely been considered before. Hence, there is a lack of research in lateral power devices integrated on SOS. Self-heating effects in existing silicon-on-insulator (SOI) lateral power devices degrade the device performance and their reliability. Use of SOS substrates could alleviate these problems though they would require a different approach in lateral power device engineering. This paper purposes a new power SOS LDMOS structure with reduced transient self-heating effects and enhanced current capability compared to the conventional SOI counterpart. The proposed lateral power structure integrated on SOS substrates is analyzed by electro-thermal simulations. The field plate is enlarged (extended field plate (EFP)) along the drift region, reaching the drain region. The EFP includes an oxide step which improves the "on-state resistance-breakdown voltage" trade-off ( RONxS- Vbr).

  12. Study on kinetics of hydrogen dissolution and hydrogen solubility in oxides using imaging plate technique

    Energy Technology Data Exchange (ETDEWEB)

    Hashizume, K., E-mail: hashi@nucl.kyushu-u.ac.jp [Interdisciplinary Graduate School of Engineering Science, Kyushu Univ., Fukuoka (Japan); Ogata, K.; Nishikawa, M.; Tanabe, T. [Interdisciplinary Graduate School of Engineering Science, Kyushu Univ., Fukuoka (Japan); Abe, S.; Akamaru, S.; Hatano, Y. [Hydrogen Isotope Research Center, Univ. of Toyama, Toyama (Japan)

    2013-11-15

    Using a tritium imaging plate technique, kinetics of tritium dissolution and its solubility in several oxides were examined. Mirror-polished single crystals of alumina, spinel and zirconia were used as specimens, which were exposed to 133 Pa of a tritium(T)–deuterium(D) gas mixture (T/(T + D) ∼ 0.17) at temperatures ranging from 673 to 973 K for 1–5 h. The T surface activity on the specimens increased with increasing temperature and exposure time, it almost saturated at 873 K and reached 2 × 10{sup 5} Bq/cm{sup 2} (1 × 10{sup 14} T/cm{sup 2}), and no clear difference appeared among the types of specimens. The T activity in the oxide bulk also increased with temperature, in which there was a trend for the oxides: spinel ≧ zirconia ≧ alumina. In the T dissolution process for all oxides, the concentration gradient due to its diffusion was not observed even for short exposure times: the T density was almost uniform over the specimens in transition states and increased with exposure time up to the saturated value. These experimental results suggested that the rate-controlling process of T dissolution in the temperature region should be not its diffusion in the oxides but dissociation of hydrogen molecules (T–D mixture in this case) into atoms, its adsorption on the surface and/or T penetration from the surface into the bulk.

  13. Inhibitive effect of Ce(III) and La(III) cations for AA2219 aluminium alloy corrosion in sodium chloride medium

    Energy Technology Data Exchange (ETDEWEB)

    Venkatasubramanian, G., E-mail: venkatguru_1966@yahoo.co.in [Department of Chemistry, Sathyabama University, Jeppiaar Nagar, Chennai 600119 (India); Sheik Mideen, A. [Department of Chemistry, Sathyabama University, Jeppiaar Nagar, Chennai 600119 (India); Jha, Abhay K. [Materials Processing Division, Vikram Sarabhai Space Centre, Indian Space Research Organisation, Thiruvananthapuram 695022 (India); Kulandainathan, M. Anbu [Electro Organic Chemistry Division, Central Electrochemical Research Institute, Karaikudi 630006 (India)

    2014-11-14

    In this paper, the rare earth chlorides were used to mitigate the dealloying of Al{sub 2}Cu intermetallic particles in aluminium alloy 2219-T87 plate exposed to 0.6 M NaCl solution. The negative shift of cathodic branches of potentiodynamic polarisation curves revealed the cathodic inhibition towards intermetallic dealloying. The low and high frequency time constants obtained from electrochemical impedance spectra revealed an increase in the corrosion resistance due to precipitation of rare earth oxides/hydroxides on the porous surface of native oxide film of aluminium alloy. Scanning electron microscopy coupled with energy dispersive X-ray analysis and atomic force microscopy revealed that intermetallic inclusions are the sites for the formation of cerium and lanthanum deposits which suppress copper redeposition and minimise galvanic interactions between the matrix and Al{sub 2}Cu particles. - Graphical abstract: Scanning electron microscopy and atomic force microscopy reveal the intermetallic inclusions, the sites for the formation of cerium and lanthanum oxide/hydroxide precipitates which prevent intermetallic de-alloying, suppress copper redeposition and minimise galvanic interactions in aluminium alloy 2219-T87 plate. - Highlights: • Ce{sup 3+} and La{sup 3+} act as cathodic inhibitors for AA2219-T87 aluminium alloy in 0.6 M NaCl. • Al{sub 2}Cu intermetallic particles are the sites for the formation of Ce and La precipitates. • The decrease in surface potential by rare earth chlorides confirms their inhibition.

  14. Inhibitive effect of Ce(III) and La(III) cations for AA2219 aluminium alloy corrosion in sodium chloride medium

    International Nuclear Information System (INIS)

    In this paper, the rare earth chlorides were used to mitigate the dealloying of Al2Cu intermetallic particles in aluminium alloy 2219-T87 plate exposed to 0.6 M NaCl solution. The negative shift of cathodic branches of potentiodynamic polarisation curves revealed the cathodic inhibition towards intermetallic dealloying. The low and high frequency time constants obtained from electrochemical impedance spectra revealed an increase in the corrosion resistance due to precipitation of rare earth oxides/hydroxides on the porous surface of native oxide film of aluminium alloy. Scanning electron microscopy coupled with energy dispersive X-ray analysis and atomic force microscopy revealed that intermetallic inclusions are the sites for the formation of cerium and lanthanum deposits which suppress copper redeposition and minimise galvanic interactions between the matrix and Al2Cu particles. - Graphical abstract: Scanning electron microscopy and atomic force microscopy reveal the intermetallic inclusions, the sites for the formation of cerium and lanthanum oxide/hydroxide precipitates which prevent intermetallic de-alloying, suppress copper redeposition and minimise galvanic interactions in aluminium alloy 2219-T87 plate. - Highlights: • Ce3+ and La3+ act as cathodic inhibitors for AA2219-T87 aluminium alloy in 0.6 M NaCl. • Al2Cu intermetallic particles are the sites for the formation of Ce and La precipitates. • The decrease in surface potential by rare earth chlorides confirms their inhibition

  15. The effect orientation of features in reconstructed atom probe data on the resolution and measured composition of T1 plates in an A2198 aluminium alloy.

    Science.gov (United States)

    Mullin, Maria A; Araullo-Peters, Vicente J; Gault, Baptiste; Cairney, Julie M

    2015-12-01

    Artefacts in atom probe tomography can impact the compositional analysis of microstructure in atom probe studies. To determine the integrity of information obtained, it is essential to understand how the positioning of features influences compositional analysis. By investigating the influence of feature orientation within atom probe data on measured composition in microstructural features within an AA2198 Al alloy, this study shows differences in the composition of T1 (Al2CuLi) plates that indicates imperfections in atom probe reconstructions. The data fits a model of an exponentially-modified Gaussian that scales with the difference in evaporation field between solutes and matrix. This information provides a guide for obtaining the most accurate information possible.

  16. Effect of Aluminium and Silicon on High Temperature Oxidation Resistance of Fe-Cr-Ni Heat Resistant Steel

    Institute of Scientific and Technical Information of China (English)

    WANG Haitao; ZHAO Qi; YU Huashun; ZHANG Zhenya; CUI Hongwei; MIN Guanghui

    2009-01-01

    Fe-Cr-Ni heat resistant steels with different contents of Al and Si were cast in intermediate frequency induction furnace with non-oxidation method. With oxidation weight gain method, the oxidation resistance of test alloys was examined at 1 200℃ for 500 h. The effects of Al and Si on oxidation resistance were studied through analyses of X-ray diffraction (XRD) and scanning electron microscope (SEM). It is shown that the composition of oxide scales is a decisive factor for the oxidation resistance of heat resistant steels. The compounded scale composed of Cr2O3, ar-Al2O3, SiO2 and Fe(Ni)Cr2O4, with flat and compact structure, fine and even grains, exhibits complete oxidation resistance at 1 200℃ Its oxidation weight gain rate is only 0.081 g/(m2·h). By the criterion of standard Gibbs formation free energy, a model of nucleation and growth of the compounded scale was established. The formation of the compounded scale was the result of the competition of being oxidated and reduction among Al, Si, and the matrix metal elements of Fe, Cr and Ni. The protection of the compounded scale was analyzed from the perspectives of electrical conductivity and strength properties.

  17. Fiber remote and real time optoelectronic dosimetry based on the optically stimulated luminescence phenomenon: Development of sensors based on aluminium oxide doped with carbon for applications in personal dosimetry

    International Nuclear Information System (INIS)

    An optical fiber sensor based on the use of classical technologies (optoelectronic, laser, optical fibers,...) can be connected to the Optically Stimulated Luminescence properties (or OSL) of the aluminium oxide doped with carbon in order to provide several new capabilities compared to usual dosimeters: remote dose measurements, quasi 'real time' dose measurements, applied to personal dosimetry thanks to a low fading level at room temperature. This thesis work shows the studies about: 1)the state of the art about dosimetry based on the aluminium oxide doped with carbon and its OSL properties (emission and stimulation spectra, glow curves, trap and recombination energy levels,...), 2)the state of the art about international standardization, not only, with regard to personal dosimetry (IEC 61066 Standard) but also to the description of operational quantities called personal dose equivalent Hp(10) and Hp(0,07), 3)the experimental development of a new sensor device based on aluminium oxide crystals (design, realization, tests,...), 4)the application of statistical Monte Carlo calculation methods (code MCNP4B) to the simulation of the sensor head in accordance with the IEC Standard 61066 with regard to the energy and angular response Hp(10). (author)

  18. Electrochemical impedance spectroscopy as a tool in the plate making process optimization.

    Science.gov (United States)

    Cigula, Tomislav; Fuchs-Godec, Regina; Gojo, Miroslav; Slemnik, Mojca

    2012-09-01

    The structure of the porous aluminium-oxide layer, which builds non-image areas, has the most significant influence on the quality of final graphical product. This paper presents the results of the application of EIS in the characterisation and detection of changes on the aluminium-oxide layer caused by chemical processing in highly alkaline solution. The Al2O3 layer was characterised using SEM, fractal dimension and surface free energy calculation and EIS analysis. The results of the investigation showed that chemical processing has a significant influence on the structure of aluminium-oxide which could lead to a decrease in the quality of the printing plate. EIS enables the detection of changes on the aluminium-oxide layer. The two equivalent circuits are proposed. Based on modelling with the obtained EIS spectra, precise evaluation of developing time in which complete removal of the photoactive layer is achieved. This makes EIS a powerful tool in optimizing chemical processing of lithographic printing plates. PMID:24061304

  19. Wearing tests on aluminium coated with diamond by triboadhesion

    Institute of Scientific and Technical Information of China (English)

    J.M.RodríguezLelis; B.D.Angulo; J.O.Colín; J.PorcayoCalderón

    2001-01-01

    In this work the results obtained from subjecting aluminium coated with diamond by tri-boadhesion to a wearing process with a plane rider. Here it is shown the ratio of the normal toshearing forces, called friction factor, as an indication of the resistance of the surface. It was foundthat the film of the aluminium coated with diamond resisted three times compared with the oxida-tion film of commercial aluminium, which for the purpose of this work was considered withoutcoating.

  20. Optimum conditions for fabricating superhydrophobic surface on copper plates via controlled surface oxidation and dehydration processes

    Science.gov (United States)

    Zhang, Yan; Li, Wen; Ma, Fumin; Yu, Zhanlong; Ruan, Min; Ding, Yigang; Deng, Xiangyi

    2013-09-01

    The superhydrophobic surfaces on copper substrate were fabricated by direct oxidation and dehydration processes, and the reaction and modification conditions were optimized. Firstly, the oxidation conditions including the concentrations of K2S2O8 and NaOH, the oxidation time were studied. It is found that the superhydrophobicity would be better if the copper plates were oxidized in 0.06 M K2S2O8 and 3.0 M NaOH solution at 65 °C for 35 min. Then, the modification conditions including modifier concentration and modification time were investigated. The results showed that 5 wt% lauric acid and 1 h modification time were suitable modification conditions for preparing copper-based superhydrophobic surfaces. The surface fabricated under optimized conditions displayed excellent superhydrophobicity of high water contact angle of 161.1° and a low contact angle hysteresis of 2.5°. The surface microstructure and composition of the superhydrophobic surfaces were also characterized by SEM and FT-IR. It is found that the highly concentrated micro/nanostructured sheets and the low surface energy materials on the surface should be responsible for the high superhydrophobicity.

  1. Optical and morphological investigation of aluminium and nickel oxide composite films deposited by spray pyrolysis method as a basis of solar thermal absorber

    Indian Academy of Sciences (India)

    A Bagheri Khatibani; S M Rozati

    2015-04-01

    Applications of alumina and nickel oxide in various fields specially in solar energy conversion technology encouraged us to study physical properties of such materials. Hence after the deposition of the thin films on glass substrate by spray pyrolysis, using X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV–visible spectrophotometry, various physical properties were investigated. Different optical quantities such as optical band gap, refractive index, extinction coefficient, dielectric constants, volume and surface energy loss functions and optical conductivity were determined. Within this paper for different nickel to aluminium ratio (from 20/80 to 80/20 ratio) at specific substrate temperatures (300°C), decrease of optical transmittance with nickel content was notable. Using the transmittance data, other optical quantities were achieved by a numerical approximation method. We also observed an increase in the volume energy loss (VELF) more than the surface energy loss (SELF) and simultaneously a decrease trend prevailed according to nickel amount. On the basic of the XRD results, the amorphous phase changed by the presence of more nickel and according to SEM, more obvious nanosized spherical grains at higher nickel ratios can be observed.

  2. The influence of impurities on the formation of protective aluminium oxides on RuAl thin films

    Energy Technology Data Exchange (ETDEWEB)

    Guitar, M.A. [Functional Materials, Materials Science Departament, Saarland University, Saarbrücken D 66123 (Germany); Ramos-Moore, E. [Facultad de Física, Pontificia Universidad Católica de Chile, Santiago 7820436 (Chile); Mücklich, F., E-mail: muecke@matsci.uni-sb.de [Functional Materials, Materials Science Departament, Saarland University, Saarbrücken D 66123 (Germany)

    2014-05-01

    Highlights: • High-temperature oxidation RuAl intermetallic thin films were studied. • Microstructural analysis with and without impurities in the RuAl film. • Effect of impurities content in the oxidation kinetics was evaluated. • Stress evaluation of the oxide grown on RuAl with and without impurities. - Abstract: Single-phase RuAl is a promising candidate for protective coating materials in applications that demand oxidation resistance at temperatures above 600 °C in air. The main advantage of this system over other B2-aluminides emerges from the adherence to α-Al{sub 2}O{sub 3} oxide scale, formed at the surface under thermal cycling conditions. In particular, the presence of impurities and reactive elements may play a crucial role in tailoring the thermo-mechanical properties of the protective oxide. The influence of Cr and Fe impurities in the isothermal oxidation of RuAl thin films deposited on austenitic stainless steel was studied in air at 900 °C. The oxidation kinetics was analysed using an Arrhenius model, whereas microstructural and stress analyses were performed on α-Al{sub 2}O{sub 3} using scanning transmission electron microscopy and X-ray diffraction, respectively. The oxidation behaviour of RuAl was affected by the presence of impurities diffused from austenitic stainless steel substrate. Cracking in the α-Al{sub 2}O{sub 3} layer was observed in the absence of impurities as a result of thermal tensile stresses generated in the oxide scale. On the contrary, compressive stresses were developed after Fe (∼62 at.%) and Cr (∼20 at.%) diffusion into the RuAl film, which enhanced the activation energy of the oxide formation, mainly due to the energy barriers produced at grain boundaries. These findings highlight the potential tailoring of RuAl stability and performance at high temperatures through bottom-up diffusion of impurities and reactive elements from different substrates.

  3. A 680 V LDMOS on a thin SOI with an improved field oxide structure and dual field plate

    Institute of Scientific and Technical Information of China (English)

    Wang Zhongjian; Cheng Xinhong; Xia Chao; Xu Dawe; Cao Duo; Song Zhaorui; Yu Yuehui; Shen Dashen

    2012-01-01

    A 680 V LDMOS on a thin SOI with an improved field oxide (FOX) and dual field plate was studied experimentally.The FOX structure was formed by an “oxidation-etch-oxidation” process,which took much less time to form,and had a low protrusion profile.A polysilicon field plate extended to the FOX and a long metal field plate was used to improve the specific on-resistance.An optimized drift region implant for linear-gradient doping was adopted to achieve a uniform lateral electric field.Using a SimBond SOI wafer with a 1.5 μm top silicon and a 3/μm buried oxide layer,CMOS compatible SOI LDMOS processes are designed and implemented successfully.The off-state breakdown voltage reached 680 V,and the specific on-resistance was 8.2 Ω·mm2.

  4. Sustainable Aluminium Systems

    Directory of Open Access Journals (Sweden)

    Sergio R. Ermolli

    2010-09-01

    Full Text Available In the present paper, an analytical presentation of some popular aluminium systems that contribute to sustainability of structures is presented. Special emphasis has been given to the properties of aluminium, while the influence of these systems in the overall performance of the structure regarding environment and economy is described. In particular, characteristics of aluminium elements such as high reflectivity and recyclability and their role in life cycle analysis (LCA are analyzed. The connections between energy efficiency and conservation of buildings and aluminium application are also discussed. Building applications such as curtain walls, window frames and facade sheets are presented and thoroughly investigated, considering their environmental and economic aspects. Furthermore, many innovative techniques that use aluminium elements in collaboration with other systems in order to produce renewable energy, such as solar panels and photovoltaics, are introduced. Finally, environmental innovations such as optimized ventilation mechanisms and light and shade management systems based on aluminium members are presented.

  5. Screen Cage Ion Plating (SCIP) and scratch testing of polycrystalline aluminum oxide

    Science.gov (United States)

    Spalvins, Talivaldis; Sliney, Harold E.; Deadmore, Daniel L.

    1992-01-01

    A screen cage ion plating (SCIP) technique was developed to apply silver films on electrically nonconducting aluminum oxide. It is shown that SCIP has remarkable throwing power; surfaces to be coated need not be in direct line of sight with the evaporation source. Scratch tests, employing a diamond stylus with a 200 micro m radius tip, were performed on uncoated and on silver coated alumina. Subsequent surface analysis show that a significant amount of silver remains on the scratched surfaces, even in areas where high stylus load produced severe crack patterns in the ceramic. Friction coefficients were lowered during the scratch tests on the coated alumina indicating that this modification of the ion planting process should be useful for applying lubricating films of soft metals to electrical insulating materials. The very good throwing power of SCIP also strongly suggests general applicability of this process in other areas of technology, e.g., electronics, in addition to tribology.

  6. 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.

  7. Ongoing characterization of passivated aluminium nanopowders

    Energy Technology Data Exchange (ETDEWEB)

    Kwok, Q.S.M.; Fouchard, R.C.; Turcotte, A-M.; Abdel-Qader, Z.; Jones, D.E.G. [Natural Resources Canada, CANMET, Canadian Explosives Research Laboratory, Ottawa, ON (Canada)

    2002-04-01

    For characterization, the thermal behaviour of two aluminium nanopowders - Alss and Alssef - in air was determined using differential scanning calorimetry (DSC), simultaneous thermogravimetry-DTA (TG-DTA) and accelerating rate calorimetry (ARC). Alss and Alssef were found to be less reactive to air than previously determined for Als And Alex, possibly due to their thicker and different type of passivating layer. Stability determination for Alss and Alssef in a wet oxidizing environment was carried out using ARC, whereas outgassing behaviour of mixtures of ammonium dinitramide (ADN) and the various aluminium powders was investigated using TG-DTA-FTIR-MS (Fourier Transform Infrared Spectrometry-Mass Spectrometry). The addition of various aluminium powders resulted in only minimal effect on the thermal stability of ADN. Electrostatic discharge, friction sensitivities of ADN and its mixtures with various aluminium powders, and thermal stability and sensitivity of mixtures of nano-sized molybdenum trioxide with aluminium nanopowders were also studied. The electrostatic discharge sensitivity of molybdenum trioxide was shown to increase by the addition of aluminium nanopowders. 23 refs., 5 tabs., 7 figs.

  8. Atomic structure and oxygen deficiency of the ultrathin aluminium oxide barrier in Al/AlOx/Al Josephson junctions

    OpenAIRE

    Lunjie Zeng; Dung Trung Tran; Cheuk-Wai Tai; Gunnar Svensson; Eva Olsson

    2016-01-01

    Al/AlOx/Al Josephson junctions are the building blocks of a wide range of superconducting quantum devices that are key elements for quantum computers, extremely sensitive magnetometers and radiation detectors. The properties of the junctions and the superconducting quantum devices are determined by the atomic structure of the tunnel barrier. The nanoscale dimension and disordered nature of the barrier oxide have been challenges for the direct experimental investigation of the atomic structure...

  9. Oxidation and corrosion behavior of titanium aluminum nitride coatings by arc ion plating

    Institute of Scientific and Technical Information of China (English)

    LI Ming-sheng; FENG Chang-jie; ZHANG Zhi-feng; WANG Fu-hui

    2006-01-01

    Composite metastable TiN and Ti1-xAlxN coatings with different Al content were deposited on 1Cr11Ni2W2MoV stainless steel for aero-engine compressor blades by arc ion plating. The results show that all coatings have a B1NaCl structure and the preferred orientation changes from (111) to (220) with increasing Al content; the lattice parameter of Ti1-xAlxN decreases with the increase of Al content. The oxidation-resistance of (Ti,Al)N coatings is significantly improved owing to the formation of Al-riched oxide on the surface of the coatings. The nitride coatings can significantly improve the corrosion-resistance of 1Cr11Ni2W2MoV stainless steel under the synergistic of water vapor and NaCl, and the corrosion-resistance becomes better when the Al content increases, because not only the quick formation of thin alumina layer prevents the further corrosion but also the formation of alumina seals the pinholes or defects in the coatings, which prevents the occurrence of localized nodules-like corrosion.

  10. Energy response of an aluminium oxide detector in kilo-voltage and mega-voltage photon beams: An EGSnrc Monte Carlo simulation study

    International Nuclear Information System (INIS)

    A Monte Carlo study of the energy response of an aluminium oxide (Al2O3) detector in kilo-voltage and mega-voltage photon beams relative to 60Co gamma rays has been performed using EGSnrc Monte Carlo simulations. The sensitive volume of the Al2O3 detector was simulated as a disc of diameter 2.85 mm and thickness 1 mm. The phantom material was water and the irradiation depth chosen was 2.0 cm in kilo-voltage photon beams and 5.0 cm in mega-voltage photon beams. The results show that the energy response of the Al2O3 detector is constant within 3% for photon beam energies in the energy range of 60 Co gamma rays to 25 MV X-rays. However, the Al2O3 detector shows an enhanced energy response for kilo-voltage photon beams, which in the case of 50 kV X-rays is 3.2 times higher than that for 60Co gamma rays. There is essentially no difference in the energy responses of LiF and Al2O3 detectors irradiated in mega-voltage photon beams when these Al2O3 results are compared with literature data for LiF thermoluminescence detectors. However, the Al2O3 detector has a much higher enhanced response compared with LiF detectors in kilo-voltage X-ray beams, more than twice as much for the case of 50 kV X-rays. (authors)

  11. Experimental Study of the Micro-Arc Oxide Coating Effect on Thermal Properties of an Aluminium Alloy Piston Head

    Directory of Open Access Journals (Sweden)

    N.Yu. Dudareva

    2015-09-01

    Full Text Available The purpose of the present study is to investigate the influence of differently sized microarc oxidation coatings, applied to the bottom of pistons made with an Al-12Si-Mg-Cu-Ni alloy, on its thermal properties by simulating the operation of a real engine. This study is based on the premise that the alumina coating thickness affects the heat transfer and temperature distribution in the piston. The analysis of thermal properties of pistons and suggestions for the optimal thermal barrier coating thickness are presented.

  12. 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...

  13. A study on the recycling of aluminium alloy 7075 scrap

    Energy Technology Data Exchange (ETDEWEB)

    Oezer, Goekhan [Yildiz Technical Univ., Yildiz (TR). Balkan Centre of Advanced Casting Technologies (BACAT); Marsoglu, Muezeyyen [Yildiz Technical Univ., Yildiz (Turkey). Dept. for Metal and Materials Science Engineering; Burgucu, Sarp

    2012-07-01

    Aluminium and its alloys have recently become an important metal whose area and amount of usage increase more and more, due to their mechanical properties, recycling ability, and penetrability. If it is considered that the bauxite, which is the raw material of aluminium is rare on earth, and also the area and amount of aluminium usage increases over time, the importance of aluminium recycling goes up. aluminium recycling has become crucial by means of both, the potential of the scrap's dependant increase on usage and the primary aluminium production, as it is providing energy and cost savings. 7xxx grades of scrap are collected with other scrap of aluminium alloys in one turn and recycled all together. As the regain of these alloys is not done by isolation of the various grades, the finally recycled ingots result in lower grades. High value aluminium scrap is regrettably not recovered, as it was anticipated. This study is dealing with 7075 aluminium alloys originated from discharged blow molding tools and the rest piece cuttings of blocks and plates. The material has been subjected to an induction furnace, and has been remelted into small ingots and hardened according to 7075 aluminium alloy parameters (hardening aluminium tooling). [German] Aluminium und seine Legierungen sind in den letzten Jahren aufgrund ihrer mechanischen Eigenschaften, ihrer Recyclingfaehigkeit und ihrer Durchlaessigkeit immer bedeutendere metallische Werkstoffe geworden. Unter Beruecksichtigung, dass Bauxit als Rohmaterial selten auf der Erde vorkommt und der Verbrauch mit der Zeit steigt, waechst die Bedeutung des Recyclings von Aluminium. Aluminiumrecycling, zumal es Energieund Kosteneinsparungen ermoeglicht, ist sowohl fuer die schrottabhaengigen Verwendungspotentiale und die PrimaerAluminiumproduktion gleichermassen bedeutend geworden. Die 7xxxx Schrottlegierungen werden in einem Arbeitsgang mit dem Schrott aus anderen Aluminiumlegierungen gesammelt und recycled. Da die

  14. Micro/nano-hybrid lens for enhancing light extraction using micro-milling and anodic aluminium oxide (AAO)

    International Nuclear Information System (INIS)

    In the recent past there has been much research towards increasing the transmission of light in optical systems by reducing the Fresnel reflection of radiation, as the reflection of light from surfaces seriously decreases the performance of an optical device. These drawbacks have been overcome by mainly two methods, which are anti-reflective coating and anti-reflective nanostructure formation. In this study, we developed a simple fabrication process for Al micro/nano hybrid lens (MNHL) moulds for efficient light extraction using micro-milling and anodic aluminum oxide (AAO). From these moulds, two different types of polymer MNHL were fabricated using hot-embossing; one was a polymer MNHL that was covered with nanostructures over the entire surface, and the other was one for which only the microlens surface was covered with nanostructures. Two different types of polymer MNHLs were evaluated and compared with each other concerning the light extraction performance. The MNHL with nanostructures only on the microlens surface exhibited a higher light extraction performance than the other by 20.7%. It is expected that the fabricated MNHL can be used for the amplification of small signals when observing the presence of bio-molecules dyed with a fluorescent material. (paper)

  15. Electrolytic deposition of aluminium-magnesium-alloys from electrolytes containing organo-aluminium complexes; Elektrolytische Abscheidung von Aluminium-Magnesium-Legierungen aus aluminiumorganischen Komplexelektrolyten

    Energy Technology Data Exchange (ETDEWEB)

    Lehmkuhl, H.; Mehler, K.; Bongard, H.; Tesche, B. [Max-Planck-Institut fuer Kohlenforschung, Muelheim an der Ruhr (Germany); Reinhold, B. [Audi AG, Ingolstadt (Germany). Technische Entwicklung

    2000-10-01

    The galvanic deposition of pure aluminium from fluoride-containing electrolytes has been developed further and for the first time aluminium and magnesium have been deposited from a toluene-solution of a halide-free organo-aluminium complex electrolyte. The rate of incorporation of magnesium can be controlled over a wide range by either adjusting the composition of the aluminium-magnesium anode or by using separate aluminium or magnesium anodic circuits. The current efficiency for both anode and cathode approaches 100%. The resulting coating is optically attractive and, depending upon the magnesium-content or the cathodic current density, can be formed as a dull or polished surface. Investigations using an electron microscope show that the surface, in contrast to that of pure aluminium, consists of spherical particles. The aluminium-magnesium coating provides excellent protection against the corrosion of magnesium components. Electrochemical investigations using, for example 25% by weight magnesium incorporation, indicate a pronounced passivity interval compared to the alloy AZ91hp. In contrast to galvanic zinc-plated and silicate-sealed examples, cyclic corrosion tests on screws simulating 10 years of exposure, show no corrosion. (orig.)

  16. The Role of Zinc Layer During Wetting of Aluminium on Zinc-coated Steel in Laser Brazing and Welding

    Science.gov (United States)

    Gatzen, M.; Radel, T.; Thomy, C.; Vollertsen, F.

    The zinc layer of zinc-coated steel is known to be a crucial factor for the spreading of liquid aluminium on the coated surface. For industrial brazing and welding processes these zinc-coatings enable a fluxless joining between aluminium and steel in many cases. Yet, the reason for the beneficial effect of the zinc to the wetting process is not completely understood. Fundamental investigations on the wetting behaviour of single aluminium droplets on different zinc-coated steel surfaces have revealed a distinct difference between coated surfaces at room temperature and at elevated temperature regarding the influence of different coating thicknesses. In this paper the case of continuous laser brazing and welding processes of aluminium and commercial galvanized zinc-coated steel sheets are presented. It is shown that in the case of bead-on-plate laser beam brazing, the coating thickness has a measureable effect on the resulting wetting angle and length but does not have a significant impact in case of overlap laser beam welding. This might be linked to different heat transfer conditions. The results also strongly indicate that proper initialbreakup of oxide layers is still required to accomplish good wetting on zinc-coated surfaces.

  17. Sodium functionalized graphene oxide coated titanium plates for improved corrosion resistance and cell viability

    International Nuclear Information System (INIS)

    Surface functionalization is an important process that has been adopted to well explore the applications of nanomaterials. In this context, we demonstrate the sodium functionalized graphene oxide (NaGO) as an excellent candidate for increasing the life time of titanium (Ti) based ortho-implants. As-prepared aqueous dispersion of NaGO was used to assemble NaGO sheets on commercially pure Ti (CpTi) plates by heat controlled spin coating. The resulting wrinkled NaGO sheets play a dual role in implant material, i.e., passive layer against corrosion and biocompatible scaffold for cell viability. The preparation, physicochemical properties, and biocompatibility of NaGO coatings formed on CpTi were reported. The electrochemical polarization studies demonstrate the relative susceptibility of control GO and NaGO coatings to corrosion, which outline that the NaGO coating act as a geometric blocking layer and hence prevent the implant surface from contacting corrosive media. The immunofluorescence and cell proliferation studies performed using human dermal fibroblasts cells showed that NaGO coatings significantly (P < 0.05) enhanced the cellular viability for longer in vitro culture period (15 days) than control GO and pristine CpTi.

  18. 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...

  19. Fatigue testing of large scale details of a large size aluminium surface effect ship

    NARCIS (Netherlands)

    Dijkstra, O.D.; Vredeveldt, A.W.; Janssen, G.Th.M.; Ortmans, P.

    1998-01-01

    The paper presents the results of two large scale fatigue tests on a detail of an aluminium surface effect ship. The overall dimensions of the specimens were: length 4.8 m, height 3.2 m and width 1.5 m (equal to the main frame spacing). The specimens consist of an aluminium structure of welded plate

  20. Analysis of the effect of transverse power distribution in an involute fuel plate with and without oxide film formation.

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R. S.

    1998-10-27

    Existing thermal hydraulics computer codes can account for variations in power and temperature in the axial and thickness directions but variations across the width of the plate cannot be accounted for. In the case of fuel plates in an annular core this can lead to significant errors which are accentuated by the presence of an oxide layer that builds up on the aluminum cladding with burnup. This paper uses a three dimensional SINDA model to account for the transverse variations in power. The effect of oxide thickness on these differences is studied in detail. Power distribution and fuel conductivity are also considered. The lower temperatures predicted with the SINDA model result in a greater margin to clad and fuel damage.

  1. Simulation, optimization and testing of a novel high spatial resolution X-ray imager based on Zinc Oxide nanowires in Anodic Aluminium Oxide membrane using Geant4

    International Nuclear Information System (INIS)

    In this work, a new generation of scintillator based X-ray imagers based on ZnO nanowires in Anodized Aluminum Oxide (AAO) nanoporous template is characterized. The optical response of ordered ZnO nanowire arrays in porous AAO template under low energy X-ray illumination is simulated by the Geant4 Monte Carlo code and compared with experimental results. The results show that for 10 keV X-ray photons, by considering the light guiding properties of zinc oxide inside the AAO template and suitable selection of detector thickness and pore diameter, the spatial resolution less than one micrometer and the detector detection efficiency of 66% are accessible. This novel nano scintillator detector can have many advantages for medical applications in the future

  2. Refractory oxides containing aluminium and barium Oxidos refratários contendo alumínio e bário

    Directory of Open Access Journals (Sweden)

    T. J. Davies

    1998-10-01

    Full Text Available Oxides containing aluminium and barium, optionally with chromium, are refractory with several possible industrial uses. A gel precursor of an oxide having the formula BaO.n(Al2xCr2yO3, where 1Oxidos contendo alumínio e bário, opcionalmente com crômio, são refratários com vários possíveis usos industriais. Foi preparado um gel precursor de um óxido de formula BaO.n(Al2xCr2yO3, com 1

  3. Synthesis and characterization of alumina nano-powders by oxidation of molten aluminium in a thermal plasma reactor: Comparison with theoretical estimation

    International Nuclear Information System (INIS)

    Alumina nano-powders are formed in a thermal plasma reactor by in-flight reaction of micron-sized aluminium powders with atmospheric oxygen. Commercially available micron-sized aluminium powders are fed into the plasma jet using argon as a carrier gas. During in-flight, the particles are vaporized and get reacted with atmospheric oxygen. The reacted vapor nucleates and condenses on the water-cooled walls of the reaction chamber. Due to fast quenching, nanosized alumina particles were formed. The particles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron micrograph (TEM) and EDX. A simple model is developed and the particle size is compared with the experimental results. The theoretical estimation for the particle size is in well agreement with experiment result

  4. 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....

  5. Influence of the Print Run on Silver Halide Printing Plates

    Directory of Open Access Journals (Sweden)

    Tomislav Cigula

    2010-09-01

    Full Text Available The most common printing technique today is lithography. The difference between printing and nonprinting areason a printing plate is accomplished by opposite physical and chemical properties of those areas (MacPhee, 1998.The printing areas are made of photoactive layer that attracts oil and chemical substances with oil solvent – printinginks. The nonprinting areas are made of aluminium-oxide which attracts water based substances – the fountainsolution.There are many of various types of photoactive layer which are used for production of offset printing plates, amongothers is silver halide layer. The usage of the silver halide technology in the graphic reproduction is not a novelty.The filmmaking phase is based on the usage of the silver halide as the photographically active ingredient, for instance,AgBr (silver bromide. The new, digital plate making technology (Computer to Plate, CtP eliminates thefilmmaking phase and therefore enables control of the printing plate’s exposure made by computer. CtP technologyeliminates the filmmaking phase, but it also results with the reduction of needed material quantities and requiredtime for the production (Limburg, 1994; Seydel, 1996.In this paper the basis of the graphic reproduction by using the silver halide digital printing plates was described.The changes of the AgX copying layer and the surface of the aluminium base in the printing process have beenobserved. The surface characteristics were determined by measuring the relevant surface roughness parameters. Inaddition, measurements of coverage values on the prints, detailed at smaller print run, were conducted.Results showed that surface changes on the printing plate are changing during printing process and that thesechanges influence transfer of the printing ink on the printing substrate. These measurements proved to be of greatinterest in the graphic reproduction as they enable us to determine consistency of the printing plates during theprinting

  6. Corrosion mechanisms of the AlFeNi aluminium alloy by water up to 250 deg

    International Nuclear Information System (INIS)

    Full text of publication follows: The AlFeNi aluminium alloy (1%Fe, 1%Ni, 1%Mg) will be used as nuclear fuel cladding in the Jules Horowitz research reactor. A better understanding of the corrosion mechanisms of this alloy in water is necessary to predict correctly the corrosion rate and the oxide thickness on the fuel plates. Corrosion tests in water at an average pH of 6.9 were hence performed on this alloy in static conditions at 70, 165 and 250 C, and in dynamic conditions at 70 C. The hydroxide film obtained on the samples corroded in autoclaves or at the slow flow rates is composed of two main layers: a dense and amorphous inner layer which grows by anionic diffusion and a porous crystalline outer layer which develops by cationic diffusion followed by a dissolution-precipitation process. The ratio of the amorphous oxide thickness to the corroded metal thickness decreases with corrosion time, thus indicating an increasing density of the amorphous oxide. Consequently, the diffusion through the inner oxide layer decreases drastically with corrosion time. The inner oxide thickness evolution is well described by a cationic diffusion model, with an apparent cationic diffusion coefficient decreasing exponentially with time. A comparison of the corrosion scales obtained in water and in vapour at 250 C showed that in the vapour, the outer precipitation oxide layer does not develop, and the inner oxide thickness is much lower. These results suggest that the anionic diffusion which controls the corrosion rate at the metal interface is coupled with the cationic diffusion and dissolution rate. The hydraulic conditions play therefore a dominant role in the corrosion rate. During dynamic experiments in once-through reactors at 70 C, the cationic release in the leaching water was measured at different times. Two leaching flow rates were used: 100 and 200 ml/h. After the first 3 hours, the aluminium and magnesium release follow a parabolic evolution, characteristic of a

  7. Study of the uniform corrosion of an aluminium alloy used for the fuel cladding of the Jules Horowitz experimental reactor; Etude de la corrosion uniforme d'un alliage d'aluminium utilise comme gainage du combustible nucleaire du reacteur experimental Jules Horowitz

    Energy Technology Data Exchange (ETDEWEB)

    Wintergerst, M. [CEA Saclay, Dept. des Materiaux pour le Nucleaire (DEN/DANS/DMN/SEMI), 91 - Gif-sur-Yvette (France)

    2008-07-01

    For the Jules Horowitz new material testing reactor, an aluminium base alloy, AlFeNi, will be used for the cladding of the fuel plates. Taking into account the thermal properties of the alloy and of its oxide, the corrosion of the fuel cans presents many problems. The aim of this thesis is to provide a growing kinetic of the oxide layer at the surface of the AlFeNi fuel can in order to predict the life time of fuel element. Thus the mechanism of degradation of the cladding will be describe in order to integrate the different parameters of the operating reactor. (A.L.B.)

  8. 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.

  9. Ultralight shape-recovering plate mechanical metamaterials.

    Science.gov (United States)

    Davami, Keivan; Zhao, Lin; Lu, Eric; Cortes, John; Lin, Chen; Lilley, Drew E; Purohit, Prashant K; Bargatin, Igor

    2015-12-03

    Unusual mechanical properties of mechanical metamaterials are determined by their carefully designed and tightly controlled geometry at the macro- or nanoscale. We introduce a class of nanoscale mechanical metamaterials created by forming continuous corrugated plates out of ultrathin films. Using a periodic three-dimensional architecture characteristic of mechanical metamaterials, we fabricate free-standing plates up to 2 cm in size out of aluminium oxide films as thin as 25 nm. The plates are formed by atomic layer deposition of ultrathin alumina films on a lithographically patterned silicon wafer, followed by complete removal of the silicon substrate. Unlike unpatterned ultrathin films, which tend to warp or even roll up because of residual stress gradients, our plate metamaterials can be engineered to be extremely flat. They weigh as little as 0.1 g cm(-2) and have the ability to 'pop-back' to their original shape without damage even after undergoing multiple sharp bends of more than 90°.

  10. Fire exposed aluminium structures

    NARCIS (Netherlands)

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

    2006-01-01

    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 pr

  11. CERN: very large magnet with aluminium winding

    Energy Technology Data Exchange (ETDEWEB)

    Wittgenstein, F.A.

    1984-10-25

    The construction of an octagonal solenoid from trapezoidal plates of Al, 6m long and 6cm thick, assembled by electron beam welding, for installation in a laboratory 50m underground is described. The objective is to create a field of 0.5T in a volume of 1000m/sup 3/ for the L3 particle detector of the LEP accelerator project. Principal dimensions and weights of the structure are given and its three stages of implementation are described, with reference to the contributions from the Swiss aluminium industry.

  12. Friction stir welding of single crystal aluminium

    DEFF Research Database (Denmark)

    Fonda, Richard Warren; Wert, John A.; Reynolds, A.P.;

    2007-01-01

    Friction stir welds were prepared in different orientations in an aluminium single crystal. The welds were quenched to preserve the microstructure surrounding the tool and then electron backscattered diffraction was used to reveal the generation of grain boundaries and the evolution...... of crystallographic texture around the tool in each weld. The extent of both dynamic recrystallisation and conventional recrystallisation varied considerably as a function of weld orientation. As the base plate begins to interact with the deformation field surrounding the tool, regions of the single crystal rotate...

  13. Impedance spectroscopy of the oxide films formed during high temperature oxidation of a cobalt-plated ferritic alloy

    Science.gov (United States)

    Velraj, S.; Zhu, J. H.; Painter, A. S.; Du, S. W.; Li, Y. T.

    2014-02-01

    Impedance spectroscopy was used to evaluate the oxide films formed on cobalt-coated Crofer 22 APU ferritic stainless steel after thermal oxidation at 800 °C in air for different times (i.e. 2, 50, 100 and 500 h). Impedance spectra of the oxide films exhibited two or three semicircles depending on the oxidation time, which correspond to the presence of two or three individual oxide layers. Coupled with scanning electron microscopy/energy-dispersive spectroscopy (SEM/EDS) and X-ray diffraction (XRD), the individual oxide layer corresponding to each semicircle was determined unambiguously. Impedance spectrum analysis of the oxide films formed on the sample after thermal exposure at 800 °C in air for 2 h led to the identification of the low-frequency and high-frequency semicircles as being from Cr2O3 and Co3O4, respectively. SEM/EDS and XRD analysis of the 500-h sample clearly revealed the presence of three oxide layers, analyzed to be Co3-xCrxO4, CoCr2O4, and Cr2O3. Although the SEM images of the 50-h and 100-h samples did not clearly show the CoCr2O4 layer, impedance plots implied their presence. The oxide scales were assigned to their respective semicircles and the electrical properties of Co3-xCrxO4, CoCr2O4 and Cr2O3 were determined from the impedance data.

  14. Morphologies and Properties of Micro-Arc Oxidation on Plate and Cylinder 2024 Al Alloy

    Institute of Scientific and Technical Information of China (English)

    Zhu Xiaowen; Han Jianmin; Cui Shihai; Li Ronghua; Li Weijing; Wang Jinhua

    2004-01-01

    Samples with two different shapes of 2024 aluminum alloy were treated with micro-arc oxidation (MAO), and the formation process and mechanism of oxidation film was analyzed. The results show that different geometrical curvature of the material has an influence upon the uniformity of films and the corrosion-resistance.

  15. The role of magnesium in the electrochemical behaviour of 5XXX aluminium-magnesium alloys

    NARCIS (Netherlands)

    Flores Ramirez, J.R.

    2006-01-01

    An investigation concerning the effects of magnesium on the intergranular corrosion susceptibility of AA5XXX aluminium alloys was carried out. In the present work, magnesium is found to be highly mobile in the bulk metal as well as in the aluminium oxide. This mobility is also found to be dependent

  16. Microstructure and interfaces of a reaction coating on aluminium alloys by laser processing

    NARCIS (Netherlands)

    Zhou, X.B.; Hosson, J.Th.M. De

    1993-01-01

    This paper reports an approach to coat a ceramic layer on aluminium alloys by means of chemical reaction. The reaction product of Al2O3 layer of 100 µm in thickness has been formed using a powder mixture of silicon oxide and aluminium by laser processing. It turns out that the large amount of heat f

  17. Recovery in aluminium

    OpenAIRE

    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-ray diffraction technique for studies of the evolution of grains within polycrystalline materials. The much smaller volume of the crystallites of interest here in comparison to grains implies that the ...

  18. Neuroprotective effect of Allium cepa L. in aluminium chloride induced neurotoxicity.

    Science.gov (United States)

    Singh, Tanveer; Goel, Rajesh Kumar

    2015-07-01

    The present study was envisaged to investigate the neuroprotective potential of Allium cepa (A. cepa) in aluminium chloride induced neurotoxicity. Aluminium chloride (50 mg/kg/day) was administered orally in mice supplemented with different doses of A. cepa hydroethanolic extract for a period of 60 days. Various behavioural, biochemical and histopathological parameters were estimated in aluminium exposed animals. Chronic aluminium administration resulted in significant motor incoordination and memory deficits, which were also endorsed biochemically as there was increased oxidative stress as well as elevated acetylcholinesterase (AChE) and aluminium levels in the brain. Supplementation with A. cepa in aluminium exposed animals significantly improved muscle coordination and memory deficits as well as reduced oxidative stress, AChE and decreased abnormal aluminium deposition in the brain. Histopathologically, there was marked deterioration visualized as decreased vacuolated cytoplasm as well as decreased pyramidal cells in the hippocampal area of mice brain which were found to be reversed with A. cepa supplementation. Administration of BADGE (PPARγ antagonist) in aluminium exposed animals reversed the neuroprotective potential of A. cepa as assessed with various behavioural, biochemical, neurochemical and histopathological estimations. In conclusion, finding of this study suggested significant neuroprotective potential of A. cepa in aluminium induced neurotoxicity. Further, the role of PPARγ receptor agonism has also been suggested as a putative neuroprotective mechanism of A. cepa, which needs further studies for confirmation.

  19. Aluminium and human breast diseases.

    Science.gov (United States)

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

    2011-11-01

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

  20. 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...

  1. Surface chemistry and cytotoxicity of reactively sputtered tantalum oxide films on NiTi plates

    International Nuclear Information System (INIS)

    NiTi, an equiatomic alloy containing nickel and titanium, exhibits unique properties such as shape memory effect and superelasticity. NiTi also forms a spontaneous protective titanium dioxide (TiO2) layer that allows its use in biomedical applications. Despite the widely perceived biocompatibility there remain some concerns about the sustainability of the alloy's biocompatibility due to the defects in the TiO2 protective layer and the presence of high amount of sub-surface Ni, which can give allergic reactions. Many surface treatments have been investigated to try to improve both the corrosion resistance and biocompatibility of this layer. For such purposes, we have sputter deposited tantalum (Ta) oxide thin films onto the surface of the NiTi alloy. Despite being one of the promising metals for biomedical applications, Ta, and its various oxides and their interactions with cells have received relatively less attention. The oxidation chemistry, crystal structure, morphology and biocompatibility of these films have been investigated. In general, reactive sputtering especially in the presence of a low oxygen mixture yields a thicker film with better control of the film quality. The sputtering power influenced the surface oxidation states of Ta. Both microscopic and quantitative cytotoxicity measurements show that Ta films on NiTi are biocompatible with little to no variation in cytotoxic response when the surface oxidation state of Ta changes. - Highlights: • Reactive sputtering in low oxygen mixture yields thicker better quality films. • Sputtering power influenced surface oxidation states of Ta. • Cytotoxicity measurements show Ta films on NiTi are biocompatible. • Little to no variation in cytotoxic response when oxidation state changes

  2. Surface chemistry and cytotoxicity of reactively sputtered tantalum oxide films on NiTi plates

    Energy Technology Data Exchange (ETDEWEB)

    McNamara, K. [Materials and Surface Science Institute, University of Limerick, Limerick (Ireland); Department of Physics & Energy, University of Limerick, Limerick (Ireland); Kolaj-Robin, O.; Belochapkine, S.; Laffir, F. [Materials and Surface Science Institute, University of Limerick, Limerick (Ireland); Gandhi, A.A. [Materials and Surface Science Institute, University of Limerick, Limerick (Ireland); Department of Physics & Energy, University of Limerick, Limerick (Ireland); Tofail, S.A.M., E-mail: tofail.syed@ul.ie [Materials and Surface Science Institute, University of Limerick, Limerick (Ireland); Department of Physics & Energy, University of Limerick, Limerick (Ireland)

    2015-08-31

    NiTi, an equiatomic alloy containing nickel and titanium, exhibits unique properties such as shape memory effect and superelasticity. NiTi also forms a spontaneous protective titanium dioxide (TiO{sub 2}) layer that allows its use in biomedical applications. Despite the widely perceived biocompatibility there remain some concerns about the sustainability of the alloy's biocompatibility due to the defects in the TiO{sub 2} protective layer and the presence of high amount of sub-surface Ni, which can give allergic reactions. Many surface treatments have been investigated to try to improve both the corrosion resistance and biocompatibility of this layer. For such purposes, we have sputter deposited tantalum (Ta) oxide thin films onto the surface of the NiTi alloy. Despite being one of the promising metals for biomedical applications, Ta, and its various oxides and their interactions with cells have received relatively less attention. The oxidation chemistry, crystal structure, morphology and biocompatibility of these films have been investigated. In general, reactive sputtering especially in the presence of a low oxygen mixture yields a thicker film with better control of the film quality. The sputtering power influenced the surface oxidation states of Ta. Both microscopic and quantitative cytotoxicity measurements show that Ta films on NiTi are biocompatible with little to no variation in cytotoxic response when the surface oxidation state of Ta changes. - Highlights: • Reactive sputtering in low oxygen mixture yields thicker better quality films. • Sputtering power influenced surface oxidation states of Ta. • Cytotoxicity measurements show Ta films on NiTi are biocompatible. • Little to no variation in cytotoxic response when oxidation state changes.

  3. First Principles Study of Aluminium Vacancy in Wurtzite Aluminium Nitride

    Institute of Scientific and Technical Information of China (English)

    GAO Ting-Ge; YI Jue-Min; ZHOU Zi-Yao; HU Xiao-Dong

    2008-01-01

    @@ We report that the aluminium vacancy in wurtzite AIN brings about two impurity levels e and a2 in the band gap, not just one single t2 level The aluminium vacancy carries a magnetic moment of 1 μB in the ground state. The molecule orbit of the aluminium vacancy becomes e↑↑ a2↑ rather than e↑↑ a2↑. The calculation is carried out by using the CASTEP code. The intrinsic symmetry of wurtzite A1N is the driving force for this spin splitting. Finally the symmetry of wurtzite AlN results in an anti-ferromagnetic coupling between the aluminium vacancies, as is predicted. Our findings are helpful to gain a more through understanding of the structural and spin property of aluminium vacancy in wurtzite AIN.

  4. Plate actuator vibration modes for levitation

    OpenAIRE

    Almurshedi, A; Atherton, M; C. Mares; Stolarski, T; Wei, B.; Wang, Y.

    2015-01-01

    The design of an aluminium or steel plate of various thicknesses for achieving levitation of a small aluminum disk is investigated by simulation using ANSYS. Each plate design is excited by an arrangement of four hard piezoelectric actuators driven with an AC voltage, which produces a centre displacement for generating a squeeze-film in the gap between the vibrating plate and the disk. Physical experiments show levitation conditions for one of the designs.

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

    OpenAIRE

    Soucek, Pavel; Cassayre, Laurent; Eloirdi, Rachel; Malmbeck, Rikard; Meier, Roland; Nourry, Christophe; Claux, Benoit; Glatz, Jean-Paul

    2014-01-01

    International audience; A chlorination route is being investigated for recovery of actinides from actinide-aluminium alloys, which originate from pyrochemical recovery of actinides from spent metallic nuclear fuel by electrochemical methods in molten LiCl-KCl. In the present work, the most important steps of this route were experimentally tested using U-Pu-Al alloy prepared by electrodeposition of U and Pu on solid aluminium plate electrodes. The investigated processes were vacuum distillatio...

  6. Fatigue tests on aluminium bridges

    NARCIS (Netherlands)

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

    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 load

  7. Fatigue tests on aluminium bridges

    NARCIS (Netherlands)

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

    2004-01-01

    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 load

  8. 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.

  9. Analytical study, by modelling methods, of the alkali and alkaline earth cations influence on the stability and the reactivity of aluminium (III) oxides or halides complexes; Etude analytique, par des techniques de modelisation, de l`influence de cations alcalins ou alcalino-terreux sur la stabilite et la reactivite de complexes de l`aluminium(III) avec des ions halogenures ou oxydes

    Energy Technology Data Exchange (ETDEWEB)

    Bouyer, F.

    1995-10-05

    The electric power consumption in aluminium production and electrorefining processes is high. A study of the electrochemical processes can be very useful for a better understanding of phenomena in electrolytic baths and then for reducing the production costs. A structural and vibrational analysis of species which exist in ionic solutions has been carried out with software based on the functional density theory. Concerning the electrolyte used for the aluminium refining, the anions study has shown that the aluminium chloro-fluoride complexes are preferentially tetrahedral. Moreover, the aluminium oxyfluoride complexes structures (which come from the alumina dissolution in cryolitic media) have been analyzed in the same way and the preferential coordination numbers for aluminium and oxygen have been shown clearly. The anionic model (which is limited to the nearest aluminium neighbours) does not allow to account for the thermodynamics of the cryolitic media. A more elaborated model has then been found to obtain the cryolite structure. The reactions enthalpies have been estimated and have lead to the calculus of species concentration gradients in liquid phase. The counterions effects as for instance sodium and calcium have been investigated. A model for the gaseous phase allowing to know the preferential species has been given. At last, a statistic thermochemistry program has been conceived and developed. It gives the thermodynamical functions at all temperature for the different complexes and allows to reckon the reactions coefficients in gaseous phase as well as the partial pressures profiles with those of calcium and sodium fluorides. (O.M.) 204 refs.

  10. Roll bonding of strained aluminium

    DEFF Research Database (Denmark)

    Staun, Jakob M.

    2003-01-01

    This report investigates roll bonding of pre-strained (å ~ 4) aluminium sheets to produce high strain material from high purity aluminium (99.996%) and commercial pure aluminium (99.6%). The degree of bonding is investigated by optical microscopy and ultrasonic scanning. Under the right circumsta......This report investigates roll bonding of pre-strained (å ~ 4) aluminium sheets to produce high strain material from high purity aluminium (99.996%) and commercial pure aluminium (99.6%). The degree of bonding is investigated by optical microscopy and ultrasonic scanning. Under the right...... circumstances both materials show good bonding, but the high purity material is excluded because of recrystallisation and the resulting loss of mechanical properties. The effect of cross stacking and roll bonding pre-strained sheets of the commercial purity material is investigated and some dependence...... of the cross rolled volume fraction is found. To further asses this effect, and the anisotropy, it is necessary to acquire knowledge about both texture and microstructure, e.g. by TEM. Roll bonding of pre-strained aluminium is found to be a possible alternative to ARB in the quest for ultra-fine grained...

  11. Aluminium, antiperspirants and breast cancer.

    Science.gov (United States)

    Darbre, P D

    2005-09-01

    Aluminium salts are used as the active antiperspirant agent in underarm cosmetics, but the effects of widespread, long term and increasing use remain unknown, especially in relation to the breast, which is a local area of application. Clinical studies showing a disproportionately high incidence of breast cancer in the upper outer quadrant of the breast together with reports of genomic instability in outer quadrants of the breast provide supporting evidence for a role for locally applied cosmetic chemicals in the development of breast cancer. Aluminium is known to have a genotoxic profile, capable of causing both DNA alterations and epigenetic effects, and this would be consistent with a potential role in breast cancer if such effects occurred in breast cells. Oestrogen is a well established influence in breast cancer and its action, dependent on intracellular receptors which function as ligand-activated zinc finger transcription factors, suggests one possible point of interference from aluminium. Results reported here demonstrate that aluminium in the form of aluminium chloride or aluminium chlorhydrate can interfere with the function of oestrogen receptors of MCF7 human breast cancer cells both in terms of ligand binding and in terms of oestrogen-regulated reporter gene expression. This adds aluminium to the increasing list of metals capable of interfering with oestrogen action and termed metalloestrogens. Further studies are now needed to identify the molecular basis of this action, the longer term effects of aluminium exposure and whether aluminium can cause aberrations to other signalling pathways in breast cells. Given the wide exposure of the human population to antiperspirants, it will be important to establish dermal absorption in the local area of the breast and whether long term low level absorption could play a role in the increasing incidence of breast cancer. PMID:16045991

  12. Experimental Study on Fatigue Characteristics for Aluminium and Al-SiC Composite Material Edge Crack Specimens under Flexural Loading Conditions

    Directory of Open Access Journals (Sweden)

    Shanmugavel P.

    2014-03-01

    Full Text Available Crack propagation studies on an Aluminium plate and Aluminium-Silicon Carbide composite plate under three point bend test conditions were done experimentally and the results so obtained been compared between Isotropic Aluminium and Aluminium-Silicon Carbide composite materials. The specimens with different crack length (a to the depth (d ratios (a/d Ratios were prepared and the fracture characteristics of the specimens with different a/d ratios have been obtained experimentally and analyzed. The analysis has been done for both the Isotropic Aluminium and Aluminium-Silicon Carbide composite material specimens with different a/d ratios. A comparative analysis between the fracture characteristics of the Aluminium and Aluminium-Silicon Carbide composite material specimens for the same a/d ratio has been done and the results been plotted. Also the fractography at the cracked surface of the Aluminium and Aluminium-Silicon Carbide composite material specimens were undertaken along with the microstructures of these specimens. An attempt has been made to relate the fracture location and propagation to the microstructure of the material specimens.

  13. The toxicity of aluminium in humans.

    Science.gov (United States)

    Exley, C

    2016-06-01

    We are living in the 'aluminium age'. Human exposure to aluminium is inevitable and, perhaps, inestimable. Aluminium's free metal cation, Alaq(3+), is highly biologically reactive and biologically available aluminium is non-essential and essentially toxic. Biologically reactive aluminium is present throughout the human body and while, rarely, it can be acutely toxic, much less is understood about chronic aluminium intoxication. Herein the question is asked as to how to diagnose aluminium toxicity in an individual. While there are as yet, no unequivocal answers to this problem, there are procedures to follow to ascertain the nature of human exposure to aluminium. It is also important to recognise critical factors in exposure regimes and specifically that not all forms of aluminium are toxicologically equivalent and not all routes of exposure are equivalent in their delivery of aluminium to target sites. To ascertain if Alzheimer's disease is a symptom of chronic aluminium intoxication over decades or breast cancer is aggravated by the topical application of an aluminium salt or if autism could result from an immune cascade initiated by an aluminium adjuvant requires that each of these is considered independently and in the light of the most up to date scientific evidence. The aluminium age has taught us that there are no inevitabilities where chronic aluminium toxicity is concerned though there are clear possibilities and these require proving or discounting but not simply ignored. PMID:26922890

  14. Fabrication experience of aluminium clad aluminium matrix dispersion fuels at BARC

    International Nuclear Information System (INIS)

    Aluminium clad, aluminium matrix plate type dispersion fuels have been fabricated in BARC in recent years as part of fuel development programme for small non-power research reactors. The present paper describes the flowsheet developed for fabrication of Al-UAlx, Al-U3Si2 and Al-U3O8 fuels at BARC. The Al-20% U alloy fuel for KAMINI neutron radiography reactor was prepared by 'melting and casting' route, followed by picture framing and roll-bonding. For higher 'U' density fuels namely, Al-UAlx, Al-U3O8 and Al-U3Si2 the 'powder metallurgy' route was followed for preparation of fuel meat. The novel features in fabrication route were: addition of Zr for stabilizing UAl3 phase in Al-20% U alloy; x-ray radiography and microdensitometric scanning of radiographs for location of fuel outline inside fuel element and for confirming homogeneous distribution of fissile atoms; immersion ultrasonic testing for confirming good bonding between mating Al surface of the fuel plate. (author)

  15. Improving Efficiency of Aluminium Sacrificial Anode Using Cold Work Process

    Science.gov (United States)

    Asmara, Y. P.; Siregar, J. P.; Tezara, C.; Ann, Chang Tai

    2016-02-01

    Aluminium is one of the preferred materials to be used as sacrificial anode for carbon steel protection. The efficiency of these can be low due to the formation of oxide layer which passivate the anodes. Currently, to improve its efficiency, there are efforts using a new technique called surface modifications. The objective of this research is to study corrosion mechanism of aluminium sacrificial anode which has been processed by cold work. The cold works are applied by reducing the thickness of aluminium sacrificial anodes at 20% and 40% of thickness reduction. The cathodic protection experiments were performed by immersion of aluminium connected to carbon steel cylinder in 3% NaCl solutions. Visual inspections using SEM had been conducted during the experiments and corrosion rate data were taken in every week for 8 weeks of immersion time. Corrosion rate data were measured using weight loss and linear polarization technique (LPR). From the results, it is observed that cold worked aluminium sacrificial anode have a better corrosion performance. It shows higher corrosion rate and lower corrosion potential. The anodes also provided a long functional for sacrificial anode before it stop working. From SEM investigation, it is shown that cold works have changed the microstructure of anodes which is suspected in increasing corrosion rate and cause de-passivate of the surface anodes.

  16. Characterisation of Ga-coated and Ga-brazed aluminium

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-05-15

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

  17. Friction surfacing of aluminium alloys

    OpenAIRE

    Pereira, Diogo Jorge O. A.

    2012-01-01

    Friction surfacing is a solid state joining process that has attracted much interest in the past decades. This technology allows joining dissimilar metallic materials while avoiding the brittle intermetallic formations, involving temperatures bellow melting point and producing like forged metal structures. Much research using different steels has been made but the same does not happen with aluminium alloys, specially using different aluminium alloys. Friction surface coatings using cons...

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

    International Nuclear Information System (INIS)

    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)

  19. Charge transfer from an adsorbed ruthenium-based photosensitizer through an ultra-thin aluminium oxide layer and into a metallic substrate

    CERN Document Server

    Gibson, Andrew J; Handrup, Karsten; Weston, Matthew; Mayor, Louise C; O'Shea, James N

    2014-01-01

    The interaction of the dye molecule N3 (cis-bis(isothiocyanato)bis(2,2-bipyridyl-4,4'-dicarboxylato)-ruthenium(II)) with the ultra-thin oxide layer on a AlNi(110) substrate, has been studied using synchrotron radiation based photoelectron spectroscopy, resonant photoemission spectroscopy (RPES) and near edge X-ray absorption fine structure spectroscopy (NEXAFS). Calibrated X-ray absorption and valence band spectra of the monolayer and multilayer coverages reveal that charge transfer is possible from the molecule to the AlNi(110) substrate via tunnelling through the ultra-thin oxide layer and into the conduction band edge of the substrate. This charge transfer mechanism is possible from the LUMO+2&3 in the excited state but not from the LUMO, therefore enabling core-hole clock analysis, which gives an upper limit of $6.0\\pm$2.5fs for the transfer time. This indicates that ultra-thin oxide layers are a viable material for use in dye-sensitized solar cells (DSSC), which may lead to reduced recombination effe...

  20. Charge transfer from an adsorbed ruthenium-based photosensitizer through an ultra-thin aluminium oxide layer and into a metallic substrate

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, Andrew J.; Temperton, Robert H.; Handrup, Karsten; Weston, Matthew; Mayor, Louise C.; O’Shea, James N., E-mail: james.oshea@nottingham.ac.uk [School of Physics and Astronomy and Nottingham Nanotechnology and Nanoscience Centre (NNNC), University of Nottingham, Nottingham NG7 2RD (United Kingdom)

    2014-06-21

    The interaction of the dye molecule N3 (cis-bis(isothiocyanato)bis(2,2-bipyridyl-4,4′-dicarbo-xylato) -ruthenium(II)) with the ultra-thin oxide layer on a AlNi(110) substrate, has been studied using synchrotron radiation based photoelectron spectroscopy, resonant photoemission spectroscopy, and near edge X-ray absorption fine structure spectroscopy. Calibrated X-ray absorption and valence band spectra of the monolayer and multilayer coverages reveal that charge transfer is possible from the molecule to the AlNi(110) substrate via tunnelling through the ultra-thin oxide layer and into the conduction band edge of the substrate. This charge transfer mechanism is possible from the LUMO+2 and 3 in the excited state but not from the LUMO, therefore enabling core-hole clock analysis, which gives an upper limit of 6.0 ± 2.5 fs for the transfer time. This indicates that ultra-thin oxide layers are a viable material for use in dye-sensitized solar cells, which may lead to reduced recombination effects and improved efficiencies of future devices.

  1. Effect of Complex Ion Concentration on the Particle Size of Nano Zinc Aluminium Oxide(ZAO)%络离子浓度对掺铝氧化锌(ZAO)纳米粉体粒径的影响

    Institute of Scientific and Technical Information of China (English)

    颜东亮; 陈林; 宋杰光

    2011-01-01

    Zinc aluminium oxide (ZAO) nanoparticles were prepared by complex salt method. A new complex salt crystal, ( NH4 ) 1.95 ( Zn0.95 Al0.05 ) ( SO4 ) 2·6H2O, was synthesized in the experiment, which proved the formation of complex ion in the initial reaction solution. The influence of complex ion concentration on the particle size of ZAO powder was researched by adjusting the addition of (NH4 )2SO4. ZAO powders were characterized by XRD, SEM and laser particle size analyzer. The results indicated that the existing of complex ion decreased the concentration of dissociative metal ion and increased the controllability of primary particle size, which was in favor of the preparation of ZAO nanometer powder.%采用络盐法制备了掺铝氧化锌(ZAO)纳米粉体.通过新复合络盐晶体-(NH4)1.95(Zn0.95Al0.05)(SO4)2·6H2O的合成证实了反应初始溶液中形成了络离子.通过改变(NH4)2SO4的加入量研究了络离子浓度对ZAO粒径的影响.通过XRD、SEM和激光粒度仪对ZAO粉体进行了表征.结果表明:络离子的存在,降低了反应初始溶液中游离金属离子的浓度,使得产物的一次粒径的可调控性增强,有利于纳米级ZAO粉体的制备.

  2. Effect of enamel top coating on oxidation behavior of multi-arc ion plating NiCrAlY coating in oxygen containing water vapor

    Institute of Scientific and Technical Information of China (English)

    XIE Dong-bai; ZHU Sheng-long; WANG Fu-hui

    2004-01-01

    The oxidation behavior of Ni-Cr-Al-Y coating produced by multi-arc ion plating with and without an enamel coating was investigated in flow oxygen and oxygen containing water vapor at 900 ℃. The results show that Ni-Cr-Al-Y coating exhibits low oxidation rate at 900 ℃ in pure oxygen and the oxidation kinetics follow the parabolic rate law. The presence of water vapor accelerates the oxidation rate of Ni-Cr-Al-Y coating and K38G alloy.The enamel top coating is very effective in protecting the Ni-Cr-Al-Y coating from water vapor corrosion attack, but the corrosion attack beneath the enamel coating is not observed.

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

    Directory of Open Access Journals (Sweden)

    Santos A

    2009-01-01

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

  4. Study of the properties of plasma deposited layers of nickel-chrome-aluminium-yttrium coatings resistant to oxidation and hot corrosion

    Directory of Open Access Journals (Sweden)

    Mihailo R. Mrdak

    2012-04-01

    Full Text Available The aim of this study was to examine the properties of Ni22Cr10Al1Y layers in order to obtain optimal structural - mechanical properties with the optimization of depositing parameters. Powder was deposited by the atmospheric plasma spray (APS process with the current intensity of 600, 700 and 800A, with a corresponding plasma gun power supply of 22KW, 34KW and 28KW. The evaluation of the Ni22Cr10Al1Y coating layers was made on the basis of their microhardness, tensile strength and microstructure performance. The best performance was obtained in the layers deposited with 800A and the 34KW plasma gun power supply. The coating with the best characteristics was tested to oxidation in the furnace for heat treatment without a protective atmosphere at 1100°C for one hour. The examination of the morphology of Ni22Cr10Al1Y powder particles was carried out on the SEM (Scanning Electron Microscope as well as the EDS analysis of the best layers. The microstructure of the deposited coating layers was examined with a light microscope. The microstructure analysis was performed according to the TURBOMECA standard. The mechanical properties of layers were evaluated by the method HV0.3 for microhardness and by tensile testing for bond strength. The research has shown that plasma gun power supply significantly affects the mechanical properties and microstructure of coatings that are of crucial importance for the protection of components exposed to high temperature oxidation and hot corrosion.

  5. 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%.

  6. 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...

  7. Pleiotropic protective roles of melatonin against aluminium-induced toxicity in rats.

    Science.gov (United States)

    Allagui, Mohamed S; Hachani, Rafik; Saidi, Saber; Feriani, Anouer; Murat, Jean C; Kacem, Kamel; El feki, Abdelfatteh

    2015-10-01

    This study aimed to investigate the potential effects of melatonin on aluminium-induced toxicity in a rat model using a set of biochemical, inflammatory, oxidant, lipid profile criteria and hepatic integrity (verified by hematoxylin-eosin staining). The results indicated that AlCl3 administration during 60 days (100 mg/kg b.w.) significantly increased the activities of transaminases AST and ALT by 46% (p aluminium-intoxication.

  8. Sol-gel derived nanocomposite materials for corrosion protection of aluminium alloys

    OpenAIRE

    Schmidt, Helmut K.; Müller, Peter; Dittfurth, Carola; Albayrak, Sener; Puhl, Anne

    2000-01-01

    Thermally curable nanocomposite coating materials have been developed to seal and protect copper-containing aluminium alloys against corrosion. The coating material was prepared via the sol-gel-process starting from epoxy functionalised silanes, nanoscaled silica and organic diole crosslinker. This coating matrix was additionally supplied with a varying content of cerium oxide (1-20 wt.%). The corrosion protective efficiency of these coatings was investigated on aluminium alloys Al 6013-T6 an...

  9. Morphology and chemical states of size-selected Pt(n) clusters on an aluminium oxide film on NiAl(110).

    Science.gov (United States)

    Beniya, Atsushi; Isomura, Noritake; Hirata, Hirohito; Watanabe, Yoshihide

    2014-12-28

    The adsorption states of size-selected Ptn clusters (7 ≤ n ≤ 20) soft-landed on an Al2O3/NiAl(110) substrate were investigated using scanning tunneling microscopy, infrared reflection absorption spectroscopy, and temperature programmed desorption. Ptn clusters lay flat on the surface with a planar structure (n ≤ 18), and three-dimensional two-layer clusters start to appear at n ≥ 19. By considering the Pt-Pt and Pt-oxide bonds in the cluster, the morphological transition could be reasonably explained. Using CO probe molecules, the chemical states of the Pt atoms inside the clusters were investigated. Two ontop CO species were observed inside the clusters, and were assigned as adsorbed CO on neutral and slightly cationic Pt atoms. Despite the first layer Pt atoms, the Ptn clusters are composed of two kinds of Pt atoms. The observed size dependence of the Pt atoms inside the clusters may contribute to the size-dependent chemical reactivity of Ptn clusters on the Al2O3 surface. PMID:25006690

  10. Effect of gallium,aluminium,and chromium on silica supported V-Mg-O catalysts during oxidative dehydrogenation of propane:Kinetic study

    Institute of Scientific and Technical Information of China (English)

    B.Ravi Kumar; Rajeev Kumar

    2008-01-01

    The oxidative dehydrogenation(ODH)of propane was conducted on gallium,aluminum.and chromium doped Si30VMgO catalysts.On doping,the concentrations of the phases responsible for the activity and selectivity increased in their concentrations.The reaction studies were conducted in a tubular steel reactor at temperatures of 753,783,813.and 843 K and atmospheric pressure.The total flow rates of the feed were chosen as 30,40,50,and 60 ml/min.The propane to oxygen ratios were chosen at 1:1,2:1,and 3:1,respectively.The effect of various dopants on the activity and selectivity of the catalysts was studied.Deactivation studies were conducted over all the catalysts.The kinetic data were analyzed in terms of power law models and Langmuir-Hinshelwood(LH)models.The kinetic data results were analyzed by comparing the effect of dopants.Statistical model discrimination was done for the proposed models.AIC and BIC criteria were used for discrimination of the models.

  11. Buckwheat stomatal traits under aluminium toxicity

    Directory of Open Access Journals (Sweden)

    Oleksandr E. Smirnov

    2014-04-01

    Full Text Available Aluminium influence on some stomatal parameters of common buckwheat (Fagopyrum esculentum Moench. was studied. Significant changes in stomatal density, stomatal index and stomatal shape coefficient under aluminium treatment were revealed. Stomatal closure and no difference in total stomatal potential conductance index of treatment plants were suggested as aluminium resistance characteristics.

  12. Does Aluminium Trigger Breast Cancer?

    Directory of Open Access Journals (Sweden)

    Peter Jennrich

    2016-08-01

    Full Text Available Summary. Breast cancer is by far the most common cancer in women in the western world. In 90% of breast cancers, environmental factors are among the causes. The frequency with which the tumour occurs in the outer upper part of the breast has risen with above average rates in recent decades. Aluminium salts as ingredients in deodorants and antiperspirants are being absorbed by the body to a greater extent than hitherto assumed. Their toxicity for healthy and diseased breast tissue cells includes various well-documented pathomechanisms. In the sense of primary and secondary prevention, the cancer-triggering potential of aluminium and its use in anti-perspirant deodorants must be re-evaluated. For the same reason the access to a targeted diagnosis and treatment of aluminium loading must be facilitated.

  13. Effect of morphology of aluminium oxide nanoparticles on viscosity and interfacial tension (IFT) and the recovery efficiency in enhanced oil recovery (EOR)

    Science.gov (United States)

    Zaid, Hasnah Mohd; Radzi, Nur Shahbinar Ahmad; Latiff, Noor Rasyada Ahmad; Shafie, Afza

    2014-10-01

    Conventional enhanced oil recovery (EOR) methods failed to extract the remaining oil from unconventional, high salinity and high temperature high pressure (HTHP) oil reservoirs. In surfactant flooding method, surfactants are injected to reduce the interfacial tension between oil and water hence sufficiently displaces oil from the reservoir. In steam flooding, high temperature steam is injected into a reservoir to heat oil to make it less viscous, making it easier to move to the production wells. However these methods fail to failed to perform because injection agents start to change its properties under the extreme condition. Therefore, nanoparticles are introduced to mitigate these challenges because of its ability to change certain factor in certain condition. Previous studies had shown that increments in the oil recovery were observed when core-flooding experiments using Aluminum Oxide (Al2O3) nanofluid were conducted. In this research, the effect of morphology of Al2O3 nanoparticles on viscosity and interfacial tension (IFT) and the recovery efficiency in EOR was studied. Al2O3 nanoparticles were synthesized and the morphology was altered by hydrothermal treatment using different concentration of NaOH. After being treated, the morphology of Al2O3 changed from hexagonal to thin lath. The IFT between crude oil and the nanofluids of the treated Al2O3 showed lower values compared to the untreated ones. It was also observed from core-flooding experiment that the Al2O3 nanofluid which had undergone treatment with 10 M NaOH gave the highest recovery of 52.50% of residual oil in place (ROIP). The change in morphology could have resulted in better dispersion and thus lead to higher recovery.

  14. Employment of fluorine doped zinc tin oxide (ZnSnOx:F) coating layer on stainless steel 316 for a bipolar plate for PEMFC

    International Nuclear Information System (INIS)

    Highlights: → Preparation of fluorine doped tin oxide (SnOx:F) and fluorine doped zinc tin oxide (ZnSnOx:F) coating layer on the surface of stainless steel 316 bipolar plate for PEMFCs (Proton Exchange Membrane Fuel Cells). → Evaluations of the corrosion resistance and the interfacial contact resistance of the bare, SnOx:F and ZnSnOx:F thin film coated stainless steel 316 bipolar plates. → Evaluation of single cell performance such as cell voltage and power density using bare stainless steel, SnOx:F and ZnSnOx:F film coated bipolar plates. - Abstract: The investigation of the electrochemical characteristics of the fluorine doped tin oxide (SnOx:F) and fluorine doped zinc tin oxide (ZnSnOx:F) was carried out in the simulated PEMFC environment and bare stainless steel 316 was used as a reference. The results showed that the ZnSnOx:F coating enhanced both the corrosion resistance and interfacial contact resistance (ICR). The corrosion current for ZnSnOx:F was 1.2 μA cm-2 which was much lower than that of bare stainless steel of 50.16 μA cm-2. The ZnSnOx:F coated film had the smallest corrosion current due to the formation of a tight surface morphology with very few pin-holes. The ZnSnOx:F coated film exhibited the highest values of the cell voltage and power density due to its having the lowest ICR values.

  15. Chapter 3. Chloric decomposition of aluminosilicate ores. 3.1. Features of chlorination of aluminium containing ores

    International Nuclear Information System (INIS)

    The features of chlorination of aluminium containing ores are considered in this article. Theoretical aspects of metals, oxides and natural compounds chlorination, specific features of synthesis of various chlorides are considered as well.

  16. Microstructure and interfaces of a reaction coating on aluminium alloys by laser processing

    OpenAIRE

    Zhou, X.B.; De Hosson, J. Th. M.

    1993-01-01

    This paper reports an approach to coat a ceramic layer on aluminium alloys by means of chemical reaction. The reaction product of Al2O3 layer of 100 µm in thickness has been formed using a powder mixture of silicon oxide and aluminium by laser processing. It turns out that the large amount of heat from the exothermic reaction has a predominate effects on the formation of the oxide layer. Further, the negative free energy of the reaction may promote the metal/oxide wetting. The micro-hardness ...

  17. 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. PMID:6337934

  18. Electrochemical properties and thermal stability of epoxy coatings electrodeposited on aluminium and modified aluminium surfaces

    Directory of Open Access Journals (Sweden)

    ZORICA M. KACAREVIC-POPOVIC

    2001-12-01

    Full Text Available The corrosion behaviour of epoxy coatings electrodeposited on aluminium, as well as on electrochemically and chemically modified aluminium were investigated during exposure to 3 % NaCl. Electrochemical impedance spectroscopy (EIS and thermogravimetric analysis (TGA were used for the determination of the protective properties of epoxy coatings on aluminium, anodized aluminium, phosphatized and chromatized-phosphatized aluminium. The protective properties of epoxy coatings on anodized and chromatized-phosphatized aluminium are significantly improved with respect to the same epoxy coatings on aluminium and phosphatized aluminium: higher values of the pore resitance and charge-transfer resistance, lower values of the coating capacitance, double-layer capacitance and relative permittivity (from EIS smaller amount of absorbed water inside the coating (From TGA. On the other hand, the lower values of the ipdt temperature indicate a lower thermal stability of the epoxy coatings on anodized and chromatized-phosphatized aluminium.

  19. Recovery mechanisms in nanostructured aluminium

    DEFF Research Database (Denmark)

    Yu, Tianbo; Hansen, Niels; Huang, Xiaoxu

    2012-01-01

    Commercial purity aluminium (99.5%) has been cold rolled to a true strain of 5.5 (99.6% reduction in thickness). The material is very strong but low temperature recovery may be a limiting factor. This has been investigated by isothermal annealing treatments in the temperature range 5–100C. Hardness...

  20. Constitutive modelling of aluminium foams

    NARCIS (Netherlands)

    Wang, W.M.; Lemmen, P.P.M.

    2001-01-01

    In this paper an aluminium foam model is proposed for a vehicle crash analysis. The model assumes that there is no coupling between stresses and strains in different principal directions. The stress in each principle direction is then interpolated from an experimental recorded uniaxial stress strain

  1. Microchemistry in aluminium sheet production

    NARCIS (Netherlands)

    Lok, Z.J.

    2005-01-01

    The production of aluminium sheet alloys from as-cast ingots is a complex process, involving several rolling operations in combination with various thermal heat treatments. Through their influence on the alloy microchemistry and microstructure, these thermomechanical treatments are all aimed at cont

  2. Micro-channel plate detector

    Energy Technology Data Exchange (ETDEWEB)

    Elam, Jeffrey W.; Lee, Seon W.; Wang, Hsien -Hau; Pellin, Michael J.; Byrum, Karen; Frisch, Henry J.

    2015-09-22

    A method and system for providing a micro-channel plate detector. An anodized aluminum oxide membrane is provided and includes a plurality of nanopores which have an Al coating and a thin layer of an emissive oxide material responsive to incident radiation, thereby providing a plurality of radiation sensitive channels for the micro-channel plate detector.

  3. 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.

  4. 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.

  5. Microstructure and mechanical properties of ceramic coatings formed on 6063 aluminium alloy by micro-arc oxidation%6063铝合金微弧氧化陶瓷涂层的显微组织和力学性能

    Institute of Scientific and Technical Information of China (English)

    项南; 宋仁国; 赵坚; 李海; 王超; 王芝秀

    2015-01-01

    以硅酸盐、硼酸盐和铝酸盐为主要溶液,分别在这3种溶液中添加纳米添加剂Al2O3和TiO2以及不添加纳米添加剂,制备6063铝合金的微弧氧化陶瓷涂层。利用扫描电镜(SEM)、电子能谱分析(EDS)、X射线衍射、硬度和摩擦磨损测试研究这些涂层的显微组织和力学性能。SEM结果显示,含纳米添加剂涂层的孔洞比不含添加剂涂层的孔洞少。X射线衍射结果表明,在每种溶液中含添加剂的涂层比不含添加剂的涂层含有更多的氧化物成分,这与EDS的分析结果是一致的。力学性能测试结果表明,含纳米添加剂Al2O3的涂层较其他各种情况下在硅酸盐、硼酸盐和铝酸盐中制备出的涂层具有更高的硬度;纳米添加剂在这3种溶液中都能够提高微弧氧化涂层的耐磨性能。此外,无论是否含有纳米添加剂,硼酸盐微弧氧化涂层相对于硅酸盐和铝酸盐涂层都表现出较差的耐磨性能。%The microstructure and mechanical properties of ceramic coatings formed on 6063 aluminium alloy obtained in silicate-, borate-and aluminate-based electrolyte without and with nanoadditive Al2O3 and TiO2 by micro-arc oxidation (MAO) were studied by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), microhardness and friction−abrasion tests, respectively. SEM results show that coatings with nanoadditive have less porosities than those without nanoadditive. XRD results reveal that nanoadditive-containing coatings contain more oxides compared with nanoadditive-free coatings in all cases, which are consistent with the EDS analysis. Mechanical properties tests show that nanoadditive Al2O3-containing coatings have higher microhardness values compared with the other coatings obtained in silicate-, borate- and aluminate-based electrolyte. On the other hand, nanoadditive has a positive effect on improving the wearing-resistance of MAO coatings

  6. Experimental investigation of thermal performance of a double-flow solar air heater having aluminium cans

    Energy Technology Data Exchange (ETDEWEB)

    Ozgen, Filiz; Esen, Mehmet; Esen, Hikmet [Department of Mechanical Education, Faculty of Technical Education, Firat University, 23119 Elazig (Turkey)

    2009-11-15

    This study experimentally investigates a device for inserting an absorbing plate made of aluminium cans into the double-pass channel in a flat-plate solar air heater (SAH). This method substantially improves the collector efficiency by increasing the fluid velocity and enhancing the heat-transfer coefficient between the absorber plate and air. These types of collectors had been designed as a proposal to use aluminium materials to build absorber plates of SAHs at a suitable cost. The collector had been covered with a 4-mm single glass plate, in order to reduce convective loses to the atmosphere. Three different absorber plates had been designed and tested for experimental study. In the first type (Type I), cans had been staggered as zigzag on absorber plate, while in Type II they were arranged in order. Type III is a flat plate (without cans). Experiments had been performed for air mass flow rates of 0.03 kg/s and 0.05 kg/s. The highest efficiency had been obtained for Type I at 0.05 kg/s. Also, comparison between the thermal efficiency of the SAH tested in this study with the ones reported in the literature had been presented, and a good agreement had been found. (author)

  7. Nouveau procédé de synthèse du nitrure d'aluminium

    Science.gov (United States)

    Haussonne, J. M.; Lostec, J.; Bertot, J. P.; Lostec, L.; Sadou, S.

    1993-04-01

    Thermodynamic considerations show that, even at room temperature, pure aluminium can react with nitrogen to form the aluminium nitride AlN. However, pure aluminium does not exist: it is always surrounded by an alumina shell that protects the metal from further reactions. Furthermore, in the hypothesis where one has been able to make aluminium react with nitrogen, an aluminium nitride shell will protect as well the metal core from further oxidation. Prompted by the Lanxide process allowing to form Al/Al2O3 composites, we have mixed aluminium powders with lithium salts, and easily synthesized pure aluminium nitride by heating the mixed powders in nitrogen at temperatures ranging from 800 to 1200 °C. Starting from aluminium powders with a specific area ranging from 0.3 to 4 m^2/g, we have been able to produce aluminium nitride with specific are ranging from 1 to 20 m^2/g. Mixed with Y203-CaO and sintered at 1720 °C in N2, we obtained AIN ceramics owning 92% density and 160 W/m.K thermal conductivity. Les calculs thermodynamiques montrent que, même à température ambiante, l'aluminium pur peut réagir avec l'azote pour former le nitrure d'aluminium AlN. Cependant, la poudre d'aluminium pur n'existe pas : ses grains sont toujours entourés d'une couche d'alumine protectrice. De plus, dans l'hypothèse où l'on pourrait faire réagir de la poudre d'aluminium avec de l'azote, il se formerait de même une couche protectrice de nitrure d'aluminium qui empêcherait le centre des grains de réagir. S'inspirant du “procédé Lanxide” permettant de réaliser des composites Al/Al2O3, nous avons mélangé de la poudre d'aluminium avec des sels de lithium, et synthétisé du nitrure d'aluminium pur en portant ce mélange dans l'azote à une température pouvant être comprise entre 800 et 1 200 °C. Utilisant des poudres d'aluminium possédant une surface spécifique comprise entre 0,3 et 4 m^2/g, nous avons obtenu une poudre de nitrure d'aluminium avec une surface sp

  8. Analysis on Oxide Defect at Surface of Hot-rolled and Pickled Plate%热轧酸洗板表面氧化缺陷分析

    Institute of Scientific and Technical Information of China (English)

    程广萍; 陈宇杰

    2013-01-01

    采用体视显微镜、扫描电镜和能谱仪等分析研究了热轧酸洗板表面的氧化物缺陷。结果表明,缺陷区为酸洗后暴露出的基体铁和沿轧向分布的在高温下形成的破碎氧化铁皮。由于氧化铁皮被压入钢板中,在后续除鳞和酸洗中均难以去除,最终成为表面缺陷。%An oxide defect at surface of hot-rolled and pickled plate was investigated by using stereo-microscope , SEM and EDS .The results show that the defective regions are iron substrate exposed owing to pickling and longitudinally distributed broken iron scale formed at high temperature .The iron oxide scale is hard to be removed by subsequently descaling and pickling because of being pressed into the plate , thus becoming a surface defect .

  9. 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...

  10. Aluminium in Allergies and Allergen immunotherapy.

    Science.gov (United States)

    Jensen-Jarolim, Erika

    2015-01-01

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

  11. Dietary aluminium Intake Level for Rent Animals in a Primary and Secondary Aluminium Industry Surrounding Area

    OpenAIRE

    Mărioara Drugă; Alexandru Trif; Mihai Drugă; Ducu Ştef; Ştefan Munteanu

    2010-01-01

    The study was carried out in an aluminium industry surrounding area on purpose to evaluate dietary aluminium intake level for rent animals originated from fodder and water consumed by them. There were taken feed and water samples in different periods and from increasing distances from industrial platform, determined the aluminium level by atomic spectroscopy and calculated the rations for cattle and poultry. Conclusions: aluminium dietary intake level by ration depends by forage period for st...

  12. Does Aluminium Trigger Breast Cancer?

    OpenAIRE

    Peter Jennrich; Claus Schulte-Uebbing

    2016-01-01

    Summary. Breast cancer is by far the most common cancer in women in the western world. In 90% of breast cancers, environmental factors are among the causes. The frequency with which the tumour occurs in the outer upper part of the breast has risen with above average rates in recent decades. Aluminium salts as ingredients in deodorants and antiperspirants are being absorbed by the body to a greater extent than hitherto assumed. Their toxicity for healthy and diseased breast tissue cells includ...

  13. A biogeochemical cycle for aluminium?

    Science.gov (United States)

    Exley, Christopher

    2003-09-15

    The elaboration of biogeochemical cycles for elements which are known to be essential for life has enabled a broad appreciation of the homeostatic mechanisms which underlie element essentiality. In particular they can be used effectively to identify any part played by human activities in element cycling and to predict how such activities might impact upon the lithospheric and biospheric availability of an element in the future. The same criteria were the driving force behind the construction of a biogeochemical cycle for aluminium, a non-essential element which is a known ecotoxicant and a suspected health risk in humans. The purpose of this exercise was to examine the concept of a biogeochemical cycle for aluminium and not to review the biogeochemistry of this element. The cycle as presented is rudimentary and qualitative though, even in this nascent form, it is informative and predictive and, for these reasons alone, it is deserving of future quantification. A fully fledged biogeochemical cycle for aluminium should explain the biospheric abundance of this element and whether we should expect its (continued) active involvement in biochemical evolution.

  14. A bakable aluminium vacuum chamber with an aluminium flange and metal seal for ultrahigh vacuum

    International Nuclear Information System (INIS)

    A bakable (2000C) aluminium alloy vacuum chamber (6063-T6) with an aluminium alloy (2219-T87) flange and metal seal (Helicoflex-HN: aluminium O-ring) has been constructed. Such components may be used in the construction of the vacuum chamber in proton synchrotrons and electron storage rings. (author)

  15. 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.

  16. 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. PMID:1542992

  17. Aluminium exclusion and aluminium tolerance in woody plants

    OpenAIRE

    Ivano eBrunner; Christoph eSperisen

    2013-01-01

    The aluminium (Al) cation Al3+ is highly rhizotoxic and is a major stress factor to plants on acid soils, which cover large areas of tropical and boreal regions. Many woody plant species are native to acid soils and are well adapted to high Al3+ conditions. In tropical regions, both woody Al accumulator and non-Al accumulator plants occur, whereas in boreal regions woody plants are non-Al accumulators. The mechanisms of these adaptations can be divided into those that facilitate the exclusion...

  18. Effect of heat treatment on anodic activation of aluminium by trace element indium

    Energy Technology Data Exchange (ETDEWEB)

    Graver, Brit [Department of Materials Science and Engineering, Norwegian University of Science and Technology, N-7491 Trondheim (Norway); Helvoort, Antonius T.J. van [Department of Physics, Norwegian University of Science and Technology, N-7491 Trondheim (Norway); Nisancioglu, Kemal, E-mail: kemal.nisancioglu@material.ntnu.n [Department of Materials Science and Engineering, Norwegian University of Science and Technology, N-7491 Trondheim (Norway)

    2010-11-15

    Research highlights: {yields} Indium segregation activates AlIn alloy surface anodically in chloride solution. {yields} Enrichment of In on Al surface can occur thermally by heat treatment at 300 {sup o}C. {yields} Increasing temperature homogenises indium in aluminium reducing anodic activation. {yields} Indium can activate AlIn surface by segregating through dealloying of aluminium. {yields} Anodic activation is caused by AlIn amalgam formation at aluminium surface. - Abstract: The presence of trace elements in Group IIIA-VA is known to activate aluminium anodically in chloride environment. The purpose of this paper is to investigate the surface segregation of trace element In by heat treatment and resulting surface activation. Model binary AlIn alloys, containing 20 and 1000 ppm by weight of In, were characterized after heat treatment at various temperatures by use of glow discharge optical emission spectroscopy, electron microscopy and electrochemical polarization. Heat treatment for 1 h at 300 {sup o}C gave significant segregation of discrete In particles (thermal segregation), which activated the surface. Indium in solid solution with aluminium, obtained by 1 h heat treatment at 600 {sup o}C, also activated by surface segregation of In on alloy containing 1000 ppm In, resulting from the selective dissolution of the aluminium component during anodic oxidation (anodic segregation). The effect of anodic segregation was reduced by decreasing indium concentration in solid solution; it had negligible effect at the 20 ppm level. The segregated particles were thought to form a liquid phase alloy with aluminium during anodic polarization, which in turn, together with the chloride in the solution destabilized the oxide.

  19. 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%.

  20. Acoustic properties of aluminium foams

    Directory of Open Access Journals (Sweden)

    García, L. E.

    2008-09-01

    Full Text Available The article discusses normal incidence sound absorption by aluminium foam manufactured with powder metallurgy technology. Aluminium foams with different surface morphologies were obtained by varying the type of precursor and adding filler materials during the foaming process. The sound absorption coefficients found for these aluminium foams were compared to the coefficient for commercial foams marketed under the name ALPORAS. The effect of foam thickness on the absorption coefficient was studied for each sample prepared. The combination of good acoustic and mechanical properties makes aluminium foams particularly attractive products. The study included an analysis of the effect of 2-, 5- and 10-cm air gaps on the sound absorption coefficient. The results showed that such gaps, which are routinely used in construction to reduce the reverberation period in indoor premises, raised the low frequency absorption coefficient significantly. This increase was found to depend on aluminium foam density and thickness and the depth of the air gap. In this same line, we have investigated the absorption coefficient of the aluminium foams combined with a mineral fiber panel.Se presenta un estudio del coeficiente de absorción acústica a incidencia normal de espumas de aluminio fabricadas mediante la técnica pulvimetalúrgica. Se fabricaron espumas de aluminio de distinta morfología superficial variando el tipo de precursor y usando materiales de relleno durante el proceso de espumación. Se muestra un estudio comparativo del coeficiente de absorción acústica de las espumas de aluminio fabricadas y las espumas comerciales conocidas como ALPORAS. Para cada muestra fabricada se estudió la influencia del espesor sobre el valor del coeficiente de absorción.El atractivo de las espumas de aluminio radica en que en ellas se combinan interesantes propiedades acústicas y mecánicas. Se analizó el efecto de una cámara de aire de 2, 5 y 10 cm de anchura sobre el

  1. Modelling of detonation cellular structure in aluminium suspensions

    Science.gov (United States)

    Briand, A.; Veyssiere, B.; Khasainov, B. A.

    2010-12-01

    Heterogeneous detonations involving aluminium suspensions have been studied for many years for industrial safety policies, and for military and propulsion applications. Owing to their weak detonability and to the lack of available experimental results on the detonation cellular structure, numerical simulations provide a convenient way to improve the knowledge of such detonations. One major difficulty arising in numerical study of heterogeneous detonations involving suspensions of aluminium particles in oxidizing atmospheres is the modelling of aluminium combustion. Our previous two-step model provided results on the effect on the detonation cellular structure of particle diameter and characteristic chemical lengths. In this study, a hybrid model is incorporated in the numerical code EFAE, combining both kinetic and diffusion regimes in parallel. This more realistic model provides good agreement with the previous two-step model and confirms the correlations found between the detonation cell width, and particle diameter and characteristic lengths. Moreover, the linear dependence found between the detonation cell width and the induction length remains valid with the hybrid model.

  2. Blast Wave Initiation of a Sheet Explosive Covered with Metal Plates.

    Directory of Open Access Journals (Sweden)

    H. S. Yadav

    1996-12-01

    Full Text Available Initiationof RDX-based sheetexplosiveby a normalincident blast wavehas been studied. Explosive sheets : (i bare (ii aluminium foil-covered and (iii sandwiched between different thicknesses of aluminium alloy metal plates, were impacted by the blast wave. The blast wave was produced by detonating a cylindrical plastic explosive charge kept symmetrically over the sheet at different stand-off distances in the air for varying the intensity of the blast wave. The values of critical distances, pressures obtained in the case of bare, foil-covered and aluminium alloy metal plates-covered sheet explosives have beenfitted to exponentialcurves.It is observedthat the sheet explosivesandwichedbetweenthe two metal plates having thicknesses between 4 and 12 rom requires initiating pressures higher than those for bare sheet explosives. If the sheet explosive is, however, covered by thin aluminium foil (0.25 mm then it is initiated by blast wave of pressure lower than that for bare or sandwiched sheet explosive. Initiation of sheet explosiveby a blast waveoccurs after a delay of 2 us when it is covered with thin aluminium foil (0.25 mm and about 7 us when it is covered with 4 mm thick aluminium plates.

  3. Transient MHD Free Convection Flow and Heat Transfer of Nanofluid past an Impulsively Started Semi-Infinite Vertical Plate

    Directory of Open Access Journals (Sweden)

    V. Rajesh

    2016-01-01

    Full Text Available In this paper, the problem of nanofluid flow and heat transfer due to the impulsive motion of a semi-infinite vertical plate in its own plane in the presence of magnetic field is analyzed by the implicit finite-difference numerical method. A range of nanofluids containing nanoparticles of aluminium oxide, copper, titanium oxide and silver with nanoparticle volume fraction range less than or equal to 0.04 are considered. The Tiwari-Das nanofluid model is employed. The velocity and temperature profiles as well as the skin friction coefficient and Nusselt number are examined for different parameters such as nanoparticle volume fraction, nanofluid type, magnetic parameter and thermal Grashof number. The present simulations are relevant to magnetic nanomaterials thermal flow processing in the chemical and metallurgical industries.

  4. Effect of plating time on growth of nanocrystalline Ni–P from sulphate/glycine bath by electroless deposition method

    Indian Academy of Sciences (India)

    N Latha; V Raj; M Selvam

    2013-08-01

    Nanocrystalline nickel phosphorus (NC-Ni–P) deposits from sulphate/glycine bath using a simple electroless deposition process is demonstrated. In the present investigation, nanoporous alumina films are formed on the aluminium surface by anodization process followed by deposition of nickel onto the pores by electroless plating method. Anodic aluminium oxide surface was first sensitized and activated by using palladium chloride solution before immersing into the electroless nickel bath. Electroless nickel plating was carried out from the optimized bath by changing the deposition time from 20 to 1800 s at a constant temperature of 80 °C and a pH of 4.0. Surface morphology, elemental composition, structure and reflectance of the deposits have been analysed by using scanning electron microscopy, atomic force microscopy, energy dispersive X-ray analysis, X-ray diffractometry and UV-visible spectroscopic studies, respectively. Electroless nickel deposits formed at an early stage produces dense uniform nanocrystals containing higher percentage of atomic phosphorus with cubic Ni (111) structure. As the deposition time increased, nanocrystalline sharp peak became amorphous and dimension of the crystal size varied from 54 to 72 nm.

  5. Preparation of 232Th Target by Molecule Plating

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>For the cross section measurement of the 232Th(α, 2n)234U reaction, thorium targets plated on the aluminium foil with 2 and 8 μm thickness are required. It was demanded that the mass thickness of the

  6. Shot peening of aluminium alloys

    International Nuclear Information System (INIS)

    Shot peening is a process of cold-hammering where a metallic surface is pelted with spherical grains. Each grain bumping into the surface acts as a hammer head and creates a small crater. The overlapping of these craters produces a residual compression layer just underneath the surface. It is well known that cracks cannot spread in a compression zone. In most cases of fatigue rupture and stress corrosion cracks propagate from the surface towards the inside so shot peening allows a longer lifetime of castings. Moreover most materials present a better resistance due to the cold-hammering effect of shot peening. Metallic surfaces can be treated in workshops or directly on site. Typical pieces that undergo shot peening on site are storing tanks, gas and steam turbines, tubes of steam generators and piping in oil or nuclear or chemical industries. This article describes shot peening from a theoretical and general point of view and presents the application to aluminium-lithium alloys. In the case of aluminium alloys shot peening can be used to shape the piece (peen-forming). (A.C.)

  7. Numerical modelling of complex shaped particle break-up with application to rolling of aluminium alloys

    OpenAIRE

    Moulin, Nicolas

    2008-01-01

    The aluminium alloy AA5182, largely employed in the form of plates used for the body panels in automotive industry, contains intermetallic particles Mg2Si and AlxFe. In as cast state, these particles (of a size > 50 µm) present complex shapes. During hot rolling, the particles are broken and redistributed in the sheet metal. However, the size and the spatial distribution of the intermetallic particles mainly control the formability of sheets after cold transformation.This work identifies morp...

  8. Shear Strength Measurements in LY-12 Aluminium Alloy During Shock Loading

    Institute of Scientific and Technical Information of China (English)

    戴兰宏; 阎敏; 沈乐天

    2004-01-01

    Lateralstress of LY-12 aluminium alloy under plate impact shock loading was measured. Based on the measured data, the Hugoniot relation and shear strength were obtained. The result has demonstrated that the shear strength of the tested material increases remarkably with the increasing longitudinal stress. This means that the assumption of constant shear strength usually adopted in shock stress calculation is not suitable for the present material.

  9. Dissolution of HFIR control plates

    International Nuclear Information System (INIS)

    A process was developed for the dissolution of High Flux Isotope Reactor (HFIR) control plates. These plates consist of aluminum metal, intensely radioactive europium oxide, and a small amount of tantalum metal. The radioactive solution will be diluted, mixed with grout, and disposed of by shale fracture. The plates are dissolved in nitric acid using a mercury catalyst. Conditions were determined that would produce a reaction rate compatible with existing equipment. 3 references, 1 figure, 3 tables

  10. The effect of atmospheric corona treatment on AA1050 aluminium

    DEFF Research Database (Denmark)

    Jariyaboon, Manthana; Møller, Per; Dunin-Borkowski, Rafal E.;

    2010-01-01

    The effect of atmospheric corona discharge on AM 050 aluminium surface was investigated using electrochemical polarization, SEM-EDX, FIB-SEM. and XPS. The corona treatment was performed with varying time (1, 5, and 15 min) in atmospheric air. A 200 nm oxide layer was generated on AA1050 after...... the 15 min air corona treatment. A significant reduction in anodic and cathodic reactivities was observed starting from 1 min exposure, which further decreased with prolonged exposure (15 min) and after delayed testing (after 30 days). The reduction in surface reactivity is due to the formation...

  11. Determination of phosphorus in hypereutectic aluminium-silicon alloys.

    Science.gov (United States)

    Mukai, K

    1972-04-01

    A reproducible method is described for determination of small amounts of phosphorus (from 0.0005% to 0.02%) in hypereutectic aluminium-silicon complex alloys. The method permits the separate determination of phosphorus in acid-soluble and acid-insoluble fractions. Phosphomolybdate is extracted with n-butanol-chloroform solvent mixture and back-extracted with a btannous chloride reducing solution. The phosphorus content of a sample cut into small pieces decreases during storage; loss of phosphorus is negligible on acid dissolution under oxidizing conditions. PMID:18961077

  12. Highly stable CuInS2@ZnS:Al core@shell quantum dots: the role of aluminium self-passivation.

    Science.gov (United States)

    Rao, Pinhua; Yao, Wei; Li, Zhichun; Kong, Long; Zhang, Wenqi; Li, Liang

    2015-05-25

    A simple approach was introduced to enhance the photostability of CuInS2@ZnS core@shell quantum dots (QDs) by doping aluminium into the ZnS shell. Aluminium in the as-prepared QDs was oxidized to Al2O3, which formed a passivation oxide layer that effectively prevents photo-degradation of QDs during long-term light irradiation.

  13. Role of phytohormones in aluminium rhizotoxicity.

    Science.gov (United States)

    Kopittke, Peter M

    2016-10-01

    Elevated concentrations of soluble aluminium (Al) reduce root growth in acid soils, but much remains unknown regarding the toxicity of this Al as well as the mechanisms by which plants respond. This review examines changes in phytohormones in Al-stressed plants. Al often results in a rapid 'burst' of ethylene in root apical tissues within 15-30 min, with this regulating an increase in auxin. This production of ethylene and auxin seems to be a component of a plant-response to toxic Al, resulting in cell wall modification or regulation of organic acid release. There is also evidence of a role of auxin in the expression of Al toxicity itself, with Al decreasing basipetal transport of auxin, thereby potentially decreasing wall loosening as required for elongation. Increasingly, changes in abscisic acid in root apices also seem to be involved in plant-responses to toxic Al. Changes in cytokinins, gibberellins and jasmonates following exposure to Al are also examined, although little information is available. Finally, although not a phytohormone, concentrations of nitric oxide change rapidly in Al-exposed tissues. The information presented in this review will assist in focusing future research efforts in examining the importance of phytohormones in plant tissues exposed to toxic levels of Al. PMID:27352002

  14. PEMBINAAN PENGERAJIN BOKOR ALUMINIUM DI DESA MENYALI

    Directory of Open Access Journals (Sweden)

    I NYOMAN GDE ANTARA, dkk.

    2014-04-01

    Full Text Available Alluminium bowl craft industrial center is located in Menyali village Sawan district Buleleng regency of Bali province. In this business development, they faced some problems such as increasingly expensive alluminium plate raw materials, decreasing selling product prices due to competition among craftsmen, difficulty in extending the marketing, lack of capital, lack of knowledge in business management, and lack of technical capacity and production innovation. Currently the organization has been formed aluminum bowl craftsmen groups, they are “Sumber Urip” and “Sumur Jaya”. This organization is still limited to tradisional associations such as a community organization, has not led to organize in a micro-enterprise or cooperation. Their organization management should not be arranged. Therefore, they need helps from the government and other institutions to build this bowl craftsmen in developing their businesses through a group of micro-enterprises or cooperations. Wishly, with formal business entity that would facilitate access to a variety of coaching and help governments andother institutions. From the SWOT analysis, it is found some problems and solutions that should be done. Alluminium bowl craftsmen groups, named “Sumber Urip” and “Sumur Jaya” is not in the form of business entity or cooperation yet, so that the results of coaching have agreed to form a cooperation. Venture capital assistance for the development and production are still needed and to be an absolute given, but a way to market more absolute yield is given, through participation in various events exhibition to introduce the product is expected to expandits market share up to overseas or exports. In the production process it has been introduced that is appropriate technology for instant a rolling tool to make a wiring groove on the outside of the bowl, so that it will simplify and speed up the process, especially by aged mothers.Keywords: aluminium bowl, Menyali

  15. Epoxy coatings electrodeposited on aluminium and modified aluminium surfaces

    Directory of Open Access Journals (Sweden)

    Lazarević Zorica Ž.

    2002-01-01

    Full Text Available The corrosion behaviour and thermal stability of epoxy coatings electrodeposited on modified aluminum surfaces (anodized, phosphatized and chromatized-phosphatized aluminium were monitored during exposure to 3% NaCl solution, using electrochemical impedance spectroscopy (EIS and thermogravimetric analysis (TGA. Better protective properties of the epoxy coatings on anodized and chromatized-phosphatized aluminum with respect to the same epoxy coatings on aluminum and phosphatized aluminum were obtained: higher values of Rp and Rct and smaller values of Cc and Cd, from EIS, and a smaller amount of absorbed water inside the coating, from TGA. On the other hand, a somewhat lower thermal stability of these coatings was obtained (smaller values of the ipdt temperature. This behavior can be explained by the less porous structure of epoxy coatings on anodized and chromatized-phosphatized aluminum, caused by a lower rate of H2 evolution and better wet ability.

  16. The Optimization of Salt Additions during Processing of Aluminium-Magnesium Alloys

    OpenAIRE

    Solberg, Egil

    2013-01-01

    Sodium is well known to be a cause for edge cracking during rolling of aluminium-magnesium alloys (AA5xxx). Due to this, requirements for the sodium contents in Al-Mg alloys are often less than 1,0 ppm. The electrolytic produced aluminium have a sodium content in the range of 30 to 200 ppm, where the highest levels are present in the most modern pot lines.To reduce sodium and other impurities like oxides and carbides several techniques are available for casthouses today. Furnace fluxing and d...

  17. The effect of ion-plated silver and sliding friction on tensile stress-induced cracking in aluminum oxide

    Science.gov (United States)

    Sliney, Harold E.; Spalvins, Talivaldis

    1993-01-01

    A Hertzian analysis of the effect of sliding friction on contact stresses in alumina is used to predict the critical load for crack generation. The results for uncoated alumina and alumina coated with ion plated silver are compared. Friction coefficient inputs to the analysis are determined experimentally with a scratch test instrument employing an 0.2 mm radius diamond stylus. A series of scratches were made at constant load increments on coated and uncoated flat alumina surfaces. Critical loads for cracking are detected by microscopic examination of cross sections of scratches made at various loads and friction coefficients. Acoustic emission (AE) and friction trends were also evaluated as experimental techniques for determining critical loads for cracking. Analytical predictions correlate well with micrographic evidence and with the lowest load at which AE is detected in multiple scratch tests. Friction/load trends are not good indicators of early crack formation. Lubrication with silver films reduced friction and thereby increased the critical load for crack initiation in agreement with analytical predictions.

  18. The effect of ion plated silver and sliding friction on tensile stress-induced cracking in aluminum oxide

    Science.gov (United States)

    Sliney, Harold E.; Spalvins, Talivaldis

    1991-01-01

    A Hertzian analysis of the effect of sliding friction on contact stresses in alumina is used to predict the critical load for crack generation. The results for uncoated alumina and alumina coated with ion plated silver are compared. Friction coefficient inputs to the analysis are determined experimentally with a scratch test instrument employing an 0.2 mm radius diamond stylus. A series of scratches were made at constant load increments on coated and uncoated flat alumina surfaces. Critical loads for cracking are detected by microscopic examination of cross sections of scratches made at various loads and friction coefficients. Acoustic emission (AE) and friction trends were also evaluated as experimental techniques for determining critical loads for cracking. Analytical predictions correlate well with micrographic evidence and with the lowest load at which AE is detected in multiple scratch tests. Friction/load trends are not good indicators of early crack formation. Lubrication with silver films reduced friction and thereby increased the critical load for crack initiation in agreement with analytical predictions.

  19. Photocatalytic discoloration of Acid Red 14 aqueous solution using titania nanoparticles immobilized on graphene oxide fabricated plate.

    Science.gov (United States)

    Akerdi, Abdollah Gholami; Bahrami, S Hajir; Arami, Mokhtar; Pajootan, Elmira

    2016-09-01

    Textile industry consumes remarkable amounts of water during various operations. A significant portion of the water discharge to environment is in the form of colored contaminant. The present research reports the photocatalytic degradation of anionic dye effluent using immobilized TiO2 nanoparticle on graphene oxide (GO) fabricated carbon electrodes. Acid Red 14 (AR 14) was used as model compound. Graphene oxide nanosheets were synthesized from graphite powder using modified Hummer's method. The nanosheets were characterized with field emission scanning electron microscope (FESEM) images, X-ray diffraction (XRD) and FTIR spectrum. The GO nanoparticles were deposited on carbon electrode (GO-CE) by electrochemical deposition (ECD) method and used as catalyst bed. TiO2 nanoparticles were fixed on the bed (GO-CE- TiO2) with thermal process. Photocatalytic processes were carried out using a 500 ml solution containing dye in batch mode. Each photocatalytic treatment were carried out for 120 min. Effect of dye concentration (mg/L), pH of solution, time (min) and TiO2 content (g/L) on the photocatalytic decolorization was investigated. PMID:27309674

  20. Dietary aluminium Intake Level for Rent Animals in a Primary and Secondary Aluminium Industry Surrounding Area

    Directory of Open Access Journals (Sweden)

    Mărioara Drugă

    2010-05-01

    Full Text Available The study was carried out in an aluminium industry surrounding area on purpose to evaluate dietary aluminium intake level for rent animals originated from fodder and water consumed by them. There were taken feed and water samples in different periods and from increasing distances from industrial platform, determined the aluminium level by atomic spectroscopy and calculated the rations for cattle and poultry. Conclusions: aluminium dietary intake level by ration depends by forage period for studied species, rations structure and distance from industrial platform and didn’t reach toxic level in any case.

  1. Ultraviolet Plasmonic Aluminium Nanoparticles for Highly Efficient Light Incoupling on Silicon Solar Cells

    Directory of Open Access Journals (Sweden)

    Yinan Zhang

    2016-05-01

    Full Text Available Plasmonic metal nanoparticles supporting localized surface plasmon resonances have attracted a great deal of interest in boosting the light absorption in solar cells. Among the various plasmonic materials, the aluminium nanoparticles recently have become a rising star due to their unique ultraviolet plasmonic resonances, low cost, earth-abundance and high compatibility with the complementary metal-oxide semiconductor (CMOS manufacturing process. Here, we report some key factors that determine the light incoupling of aluminium nanoparticles located on the front side of silicon solar cells. We first numerically study the scattering and absorption properties of the aluminium nanoparticles and the influence of the nanoparticle shape, size, surface coverage and the spacing layer on the light incoupling using the finite difference time domain method. Then, we experimentally integrate 100-nm aluminium nanoparticles on the front side of silicon solar cells with varying silicon nitride thicknesses. This study provides the fundamental insights for designing aluminium nanoparticle-based light trapping on solar cells.

  2. Aluminium Process Fault Detection and Diagnosis

    Directory of Open Access Journals (Sweden)

    Nazatul Aini Abd Majid

    2015-01-01

    Full Text Available The challenges in developing a fault detection and diagnosis system for industrial applications are not inconsiderable, particularly complex materials processing operations such as aluminium smelting. However, the organizing into groups of the various fault detection and diagnostic systems of the aluminium smelting process can assist in the identification of the key elements of an effective monitoring system. This paper reviews aluminium process fault detection and diagnosis systems and proposes a taxonomy that includes four key elements: knowledge, techniques, usage frequency, and results presentation. Each element is explained together with examples of existing systems. A fault detection and diagnosis system developed based on the proposed taxonomy is demonstrated using aluminium smelting data. A potential new strategy for improving fault diagnosis is discussed based on the ability of the new technology, augmented reality, to augment operators’ view of an industrial plant, so that it permits a situation-oriented action in real working environments.

  3. Deformation features of aluminium in tensile tests

    International Nuclear Information System (INIS)

    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 4000C, 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.)

  4. Steam Initiated Surface Modification of Aluminium Alloys

    DEFF Research Database (Denmark)

    Din, Rameez Ud

    , 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......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...

  5. Shear Viscosity of Aluminium under Shock Compression

    Institute of Scientific and Technical Information of China (English)

    LIU Fu-Sheng; YANG Mei-Xia; LIU Qi-Wen; CHEN Jun-Xiang; JING Fu-Qian

    2005-01-01

    @@ Based on the Newtonian viscous fluid model and the analytic perturbation theory of Miller and Ahrens for the oscillatory damping of a sinusoidal shock front, a flyer-impact technique is developed to investigate the effecti veviscosity of shocked aluminium.

  6. Fractographic analysis of fatigue damage in 7000 aluminium alloys.

    Science.gov (United States)

    Cvijović, Z; Vratnica, M; Gerić, K

    2008-12-01

    In this paper, an attempt is made to correlate the fatigue damage in 7000 aluminium alloys with different impurity contents to the microstructural features and to explain their interdependence through fractographic observations. The Paris constants of these alloys in the form of hot-forged plates subjected to the overaged T73 temper are evaluated and differences in the fatigue crack growth rate described by striation spacing measurements. Scanning electron microscopy analysis of fatigue fracture surfaces revealed that the type and morphological parameters of coarse intermetallic particles play a critical role in fatigue crack growth behaviour. The elemental distribution determined by means of energy-dispersive spectroscopy analysis showed that the fractured particles accelerating the crack advances are larger particles of Fe-rich phases. The fatigue crack growth rate increases considerably with increasing amounts of these particles. The smaller eta, S and Mg(2)Si particles contribute beneficially to fatigue life.

  7. Shock wave synthesis of aluminium nitride with rocksalt structure

    Science.gov (United States)

    Keller, K.; Schlothauer, T.; Schwarz, M.; Heide, G.; Kroke, E.

    2012-03-01

    The high pressure phase of aluminium nitride with rocksalt structure (rs) is a ceramic with high potential and a challenging material to investigate. The rs-AlN was synthesised and recovered by shock wave experiments using the flyer-plate method with multiple reflections at peak pressures between 15 and 43 GPa. Successful syntheses were carried out using AlN nanopowder with ambient pressure wurtzite structure (w-AlN) as starting material. The high pressure modification could, however, not be obtained when starting from submicron w-AlN. The recovery of rs-AlN is sensitive to the synthesis conditions as these influence the reconversion of rs-AlN to w-AlN.

  8. Bone marrow aluminium storage in renal failure.

    OpenAIRE

    Kaye, M.

    1983-01-01

    Using the staining method for aluminium with the ammonium salt of aurine tricarboxylic acid, aluminon, 18 patients with end stage renal disease gave positive reactions in iliac crest bone biopsies and 11 of these had positive staining in the bone marrow. In one the marrow was positive and the bone negative. The marrow reaction is putatively regarded as caused by aluminium storage in unidentified cells, possibly of the macrophage system which are strongly fluorescent when examined after prior ...

  9. DETERMINATION OF IMPURITY ELEMENTS IN ALUMINIUM

    Institute of Scientific and Technical Information of China (English)

    侯小琳; 张永保

    1994-01-01

    Twenty five impurity elements in aluminium applied as reactor material are determined.Titanium and nickel are determined with epithermal neutron activation analysis(NAA),magnesium and silicon by inductance coupling plasma emission spectra(ICP),other elements by thermal NAA.The fission coefficient of uranium is given by an experiment,the interferences of uranium to Ce,Nd,Mo,Zr,La,Sm are subtracted.The detection limits of these methods to all of impurity elements in aluminium are calculated.

  10. 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....

  11. Electrical Conductivity of Aluminium Alloy Foams

    Institute of Scientific and Technical Information of China (English)

    凤仪; 郑海务; 朱震刚; 祖方遒

    2002-01-01

    Closed-cell aluminium alloy foams were produced using the powder metallurgical technique. The effect of porosityand cell diameter on the electrical conductivity of foams was investigated and the results were compared with anumber of models. It was found that the percolation theory can be successfully applied to describe the dependenceof the electrical conductivity of aluminium alloy foams on the relative density. The cell diameter has a negligibleeffect on the electrical conductivity of foams.

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

    Science.gov (United States)

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

    2015-04-01

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

  13. Heat treatment of aluminium strip coils; Gluehbehandlung von Aluminium-Bandbunden

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, Dominik; Dambauer, Georg [LOI Thermprocess GmbH, Essen (Germany)

    2012-08-15

    Nowadays, aluminium strip coils are increasingly heat-treated in single-coil lifting hearth furnaces SCL. Flexible, individual heat treatment allows fast reactions to short term requirements for the production of aluminium strip and offers energy saving possibilities. The following report describes the advantages of single-coil hearth furnaces in terms of flexibility, energy consumption and possible configurations. (orig.)

  14. A preliminary study of the dermal absorption of aluminium from antiperspirants using aluminium-26.

    Science.gov (United States)

    Flarend, R; Bin, T; Elmore, D; Hem, S L

    2001-02-01

    Aluminium chlorohydrate (ACH), the active ingredient in many antiperspirants, was labeled with the radioisotope 26Al. The labeled ACH was then fractionated into about 100 samples using gel filtration chromatography. Each fraction was analyzed for 26Al and total aluminium content. Aluminium-26 was only detected in the fractions that also contained aluminium, which verified that the ACH was uniformly labeled. 84 mg of the labeled ACH was then applied to a single underarm of two adult subjects with blood and urine samples being collected over 7 weeks. Tape-stripping and mild washings of the skin were also collected for the first 6 days. Results indicate that only 0.012% of the applied aluminium was absorbed through the skin. At this rate, about 4 microg of aluminium is absorbed from a single use of ACH on both underarms. This is about 2.5% of the aluminium typically absorbed by the gut from food over the same time period. Therefore, a one-time use of ACH applied to the skin is not a significant contribution to the body burden of aluminium.

  15. Design of welded aluminium connections (Entwurf und Berechnung von Aluminium Schweissverbindungen)

    NARCIS (Netherlands)

    Soetens, F.

    1998-01-01

    In the past two decades considerable research effort has been put into welded aluminium connections in order to better understand their structural behaviour and to up-date the design rules in the existing standards at the time [1]. Since weids in aluminium are more critical compared to steel, the ab

  16. Aluminium exclusion and aluminium tolerance in woody plants

    Directory of Open Access Journals (Sweden)

    Ivano eBrunner

    2013-06-01

    Full Text Available The aluminium (Al cation Al3+ is highly rhizotoxic and is a major stress factor to plants on acid soils, which cover large areas of tropical and boreal regions. Many woody plant species are native to acid soils and are well adapted to high Al3+ conditions. In tropical regions, both woody Al accumulator and non-Al accumulator plants occur, whereas in boreal regions woody plants are non-Al accumulators. The mechanisms of these adaptations can be divided into those that facilitate the exclusion of Al3+ from root cells (exclusion mechanisms and those that enable plants to tolerate Al3+ once it has entered the root and shoot symplast (internal tolerance mechanisms. The biochemical and molecular basis of these mechanisms have been intensively studied in several crop plants and the model plant Arabidopsis. In this review, we examine the current understanding of Al3+ exclusion and tolerance mechanisms from woody plants. In addition, we discuss the ecology of woody non-Al accumulator and Al accumulator plants, and present examples of Al3+ adaptations in woody plant populations. This paper complements previous reviews focusing on crop plants and provides insights into evolutionary processes operating in plant communities that are widespread on acid soils.

  17. Experimental investigation of hardness of FSW and TIG joints of Aluminium alloys of AA7075 and AA6061

    Directory of Open Access Journals (Sweden)

    Chetan Patil

    2016-07-01

    Full Text Available This paper reports hardness testing conducted on welded butt joints by FSW and TIG welding process on similar and dissimilar aluminium alloys. FSW joints were produced for similar alloys of AA7075T651 and dissimilar alloys of AA7075T651- AA6061T6. The Friction stir welds of AA7075 & AA6061 aluminium alloy were produced at different tool rotational speeds of 650,700, 800, 900, 1000 and transverse speed of 30, 35, 40 mm/min. TIG welding was conducted along the rolling direction of similar and dissimilar aluminium plates. The Brinell hardness testing techniques were employed to conduct the tests; these tests were conducted on the welds to ascertain the joint integrity before characterization to have an idea of the quality of the welds

  18. Calculation of Specific Heat for Aluminium Thin Films

    Institute of Scientific and Technical Information of China (English)

    LU Yao; SONG Qing-Lin; XIA Shan-Hong

    2005-01-01

    @@ We employ Prasher's non-dimensional form to analyse the size effects on specific heat of Al thin films. Compared the calculation results of pure aluminium film with the experimental data, it is found that the reduction of phonon states is not the main reason of the size effect on the specific heat Al thin films with thickness from 10hm to 370nm. However, the Al thin film in air usually has an oxidation layer and the specific heat of the layer is smaller than Al. By including the contribution of the oxidation layer to the thin-film specific heat, the calculation results are much closer to the experimental data. This may be a possible reason of the size effects on specific heat of Al thin films.

  19. PEM fuel cell bipolar plate material requirements for transportation applications

    Energy Technology Data Exchange (ETDEWEB)

    Borup, R.L.; Stroh, K.R.; Vanderborgh, N.E. [Los Alamos National Lab., NM (United States)] [and others

    1996-04-01

    Cost effective bipolar plates are currently under development to help make proton exchange membrane (PEM) fuel cells commercially viable. Bipolar plates separate individual cells of the fuel cell stack, and thus must supply strength, be electrically conductive, provide for thermal control of the fuel stack, be a non-porous materials separating hydrogen and oxygen feed streams, be corrosion resistant, provide gas distribution for the feed streams and meet fuel stack cost targets. Candidate materials include conductive polymers and metal plates with corrosion resistant coatings. Possible metals include aluminium, titanium, iron/stainless steel and nickel.

  20. Radiation effects on an unsteady MHD natural convective flow of a nanofluid past a vertical plate

    Directory of Open Access Journals (Sweden)

    Parasuraman Loganathan

    2015-01-01

    Full Text Available Numerical analysis is carried out on an unsteady MHD natural convective boundary layer flow of a nanofluid past an isothermal vertical plate in the presence of thermal radiation. The governing partial differential equations are solved numerically by an efficient, iterative, tri-diagonal, semi-implicit finite-difference method. In particular, we investigate the effects of radiation, magnetic field and nanoparticle volume fraction on the flow and heat transfer characteristics. The nanofluids containing nanoparticles of aluminium oxide, copper, titanium oxide and silver with nanoparticle volume fraction range less than or equal to 0.04 are considered. The numerical results indicate that in the presence of radiation and magnetic field, an increase in the nanoparticle volume fraction will decrease the velocity boundary layer thickness while increasing the thickness of the thermal boundary layer. Meanwhile, an increase in the magnetic field or nanoparticle volume fraction decreases the average skin-friction at the plate. Excellent validation of the present results has been achieved with the published results in the literature in the absence of the nanoparticle volume fraction.

  1. Fundamental studies of growth mechanisms in physical vapour deposition of aluminium

    CERN Document Server

    Knorr, N J

    2000-01-01

    temperature could be independently controlled due to the low deposition rate of the aluminium. The depositions were performed in a UHV environment to ensure that film growth was not mediated by contamination. The ion energy range used was 10-75eV and the substrate temperature varied from -100 deg C to 200 deg C. The depositions were onto silicon (100) with a native oxide surface, except for a set of depositions which were performed on to silicon with the native oxide surface removed. The cleanliness of the depositions was verified using in-situ XPS analysis and after deposition the structure of the aluminium films was inferred from measurements using SEM, TEM, AFM XRD and Nano-indendation. This information allowed the mechanisms of growth of the aluminium films to be investigated. In addition to the extensive array of IBDR depositions a series of aluminium films were deposited using evaporation and sputtering. These films were grown at substrate temperatures between room temperate and 200 deg C. The use of ev...

  2. Aluminium and breast cancer: Sources of exposure, tissue measurements and mechanisms of toxicological actions on breast biology.

    Science.gov (United States)

    Darbre, Philippa D; Mannello, Ferdinando; Exley, Christopher

    2013-11-01

    This review examines recent evidence linking exposure to aluminium with the aetiology of breast cancer. The human population is exposed to aluminium throughout daily life including through diet, application of antiperspirants, use of antacids and vaccination. Aluminium has now been measured in a range of human breast structures at higher levels than in blood serum and experimental evidence suggests that the tissue concentrations measured have the potential to adversely influence breast epithelial cells including generation of genomic instability, induction of anchorage-independent proliferation and interference in oestrogen action. The presence of aluminium in the human breast may also alter the breast microenvironment causing disruption to iron metabolism, oxidative damage to cellular components, inflammatory responses and alterations to the motility of cells. The main research need is now to investigate whether the concentrations of aluminium measured in the human breast can lead in vivo to any of the effects observed in cells in vitro and this would be aided by the identification of biomarkers specific for aluminium action.

  3. Reactive sputter deposition of Al doped TiOx thin films using titanium targets with aluminium inserts

    International Nuclear Information System (INIS)

    Highlights: •Ti(Al)Ox thin films with varying Al fractions and increasing discharge current were deposited. •The reactive sputtering behaviour of Ti targets with Al inserts was studied. •XPS and EDX were used to check the stoichiometry of the films. •Optical transmittance measurements were performed to determine the band gap. -- Abstract: Al doped TiOx thin films were deposited using Ti targets with Al inserts. Both the effect of the number of aluminium inserts and the discharge current on the discharge voltage, on the aluminium content in the thin films, and on the reactive sputtering behaviour was investigated. The aluminium content in the film was measured using X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray spectroscopy (EDX). X-ray diffraction (XRD) revealed that the as-deposited thin films were amorphous, independent of the aluminium content or the discharge current. The XPS results indicated that the oxide films were substoichiometric. The optical band gap of the Ti(Al)Ox thin films was investigated as a function of the aluminium concentration and the discharge current. The addition of aluminium results in a significant increase of the band gap at low discharge currents, while no significant influence on the band gap was found at higher currents

  4. 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.

  5. Study of the aqueous corrosion mechanisms and kinetics of the AlFeNi aluminium based alloy used for the fuel cladding in the Jules Horowitz research reactor

    International Nuclear Information System (INIS)

    For the Jules Horowitz new material-testing reactor (JHR), an aluminium base alloy, called AlFeNi, will be used for the cladding of the fuel plates. This alloy (Al - 1% Fe - 1% Ni - 1 % Mg), which is already used as fuel cladding, was developed for its good corrosion resistance in water at high temperatures. However, few studies dealing with the alteration process in water and the relationships with irradiation effects have been performed on this alloy. The conception of the JHR fuel requires a better knowledge of the corrosion mechanisms. Corrosion tests were performed in autoclaves at 70 C, 165 C and 250 C on AlFeNi plates representative of the fuel cladding. Several techniques were used to characterize the corrosion scale: SEM, TEM, EPMA, XRD, Raman spectroscopy. Our observations show that the corrosion scale is made of two main layers: a dense amorphous scale close to the metal and a porous crystalline scale in contact with the water. More than the morphology, the chemical compositions of both layers are different. This duplex structure results from a mixed growth mechanism: an anionic growth to develop the inner oxide and a cationic diffusion followed by a dissolution-precipitation process to form the outer one. Dynamic experiments at 70 C and corrosion kinetics measurements have demonstrated that the oxide growth process is controlled by a diffusion step associated to a dissolution/precipitation process. A corrosion mechanism of the AlFeNi alloy in aqueous media has been proposed. Then post-irradiation exams performed on irradiated fuel plates were used to investigate the effects of the irradiation on the corrosion behaviour in the reactor core. (author)

  6. 经环氧乙烷灭菌的培养皿对Ames试验的影响%Effects of the ethylene oxide-sterilized Petri plate on Ames test

    Institute of Scientific and Technical Information of China (English)

    张建军; 姜凌; 张海娇; 柴振海

    2014-01-01

    目的:研究经环氧乙烷灭菌的培养皿对Ames试验的影响。方法:采用Ames试验平板掺入法,分别使用不同储存时间及是否通风等情况下的环氧乙烷灭菌培养皿,计数TA97、TA98、TA100、TA102及TA1535菌株的回变菌落数。结果:灭菌后存放1个月左右(25 d)的培养皿中环氧乙烷的残留在活化和非活化两种条件下均能引起TA100和TA1535菌株的回变菌落数增多(TA100,约自发回变数的1.5倍;TA1535,约自发回变数的10倍),而经通风或延长培养皿储存时间可减少环氧乙烷残留并消除这种致突变作用。结论:在一定条件下,经环氧乙烷灭菌的培养皿对Ames试验中TA100、TA1535菌株有致突变性。%OBJECTIVE: Study on effects of the ethylene oxide-sterilized Petri plate on Ames test. METHODS:In the plate incorporation test of Salmonella typhimurium,the revertant colonies of TA97, TA98,TA100,TA102 and TA1535 on the ethylene oxide sterilized Petri plates stored for different periods of time or by ventilation was counted. RESULTS:Ethylene oxide residuals in the Petri plates one month after sterilized increased the revertant colonies of TA100 and TA1535(TA100,about 1.5 fold of the spontaneous revertant colonies;TA1535,about 10 fold of the spontaneous revertant colonies),and extending storage or ventilation could reduce the plate ethylene oxide residuals to a level that caused no mutagenetic effects. CONCLUSION:Under certain conditions,ethylene oxide-sterilized Petri plate could induce TA100 and TA1535 mutagenicity on Ames test.

  7. Effect of aluminium phosphate as admixture on oxychloride cement

    Indian Academy of Sciences (India)

    M P S Chandrawat; R N Yadav

    2000-02-01

    The effect of admixing of aluminium phosphate on oxychloride cement in the matrix has been investigated. It is shown that aluminium phosphate retards the setting process of the cement and improves water-tightness.

  8. Structural colours and applications to anodised aluminium surfaces

    DEFF Research Database (Denmark)

    Johansen, Villads Egede

    This thesis investigates possible ways of creating aluminium with a milky white, metallic appearance for decorative purposes. Since white cannot be obtained through traditional absorption based dyeing of aluminium, optical mechanisms based on scattering by nanostructures are studied in order...

  9. Solidification of spent TBP solvent with aluminium chloride compounds

    International Nuclear Information System (INIS)

    The new techniques for processing spent TBP was investigated. It was proved that treatment of TBP containing DBP with aluminium chloride resulted in the formation of aluminium phosphate suitable for long term storage and final disposal

  10. Recovery of actinides from actinide–aluminium alloys by chlorination: Part II

    Energy Technology Data Exchange (ETDEWEB)

    Souček, P., E-mail: pavel.soucek@ec.europa.eu [European Commission, JRC, Institute for Transuranium Elements, Postfach 2340, 76125 Karlsruhe (Germany); Cassayre, L. [Laboratoire de Génie Chimique (LGC), Département Procédés Electrochimiques, CNRS-UMR 5503, Université de Toulouse III – Paul Sabatier, 31062 Toulouse Cedex 9 (France); Eloirdi, R.; Malmbeck, R.; Meier, R.; Nourry, C.; Claux, B.; Glatz, J.-P. [European Commission, JRC, Institute for Transuranium Elements, Postfach 2340, 76125 Karlsruhe (Germany)

    2014-04-01

    A chlorination route is being investigated for recovery of actinides from actinide–aluminium alloys, which originate from pyrochemical recovery of actinides from spent metallic nuclear fuel by electrochemical methods in molten LiCl–KCl. In the present work, the most important steps of this route were experimentally tested using U–Pu–Al alloy prepared by electrodeposition of U and Pu on solid aluminium plate electrodes. The investigated processes were vacuum distillation for removal of the salt adhered on the electrode, chlorination of the alloy by chlorine gas and sublimation of the AlCl{sub 3} formed. The processes parameters were set on the base of a previous thermochemical study and an experimental work using pure UAl{sub 3} alloy. The present experimental results indicated high efficiency of salt distillation and chlorination steps, while the sublimation step should be further optimised.

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

    Science.gov (United States)

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

    2014-04-01

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

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

    Science.gov (United States)

    Yüksel, N.; Avcı, A.; Kılıç, M.

    2012-09-01

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

  13. Shear modulus of shock-compressed LY12 aluminium up to melting point

    Institute of Scientific and Technical Information of China (English)

    Yu Yu-Ying; Tan Hua; Hu Jian-Bo; Dai Cheng-Da

    2008-01-01

    Asymmetric plate impact experiments are conducted on LY12 aluminium alloy in a pressure range of 85-131 GPa.The longitudinal sound speeds are obtained from the time-resolved particle speed profiles of the specimen measured with Velocity Interferometer System for Any Reflector (VISAR) technique,and they are shown to be good agreement with our previously reported data of this alloy in a pressure range of 20-70 CPa,and also with those of 2024 aluminium reported by McQueen.Using all of the longitudinal speeds and the corresponding bulk speeds calculated from the Gruneisen equation of state (EOS),shear moduli of LY12 aluminium alloy are obtained.A comparison of the shear moduli in the solid phase region with those estimated from the Steinberg model demonstrate that the latter are systematically lower than the measurements.By re-analysing the pressure effect on the shear modulus,a modified equation is proposed,in which the pressure term of P/η1/3 in the Steinberg model is replaced by a linear term.Good agreement between experiments and the modified equation is obtained,which implies that the shear modulus of LY12 aluminium varies linearly both with pressure and with temperature throughout the whole solid phase region.On the other hand,shear modulus of aluminium in a solid-liquid mixed phrase region decreases gradually and smoothly,a feature that is very different from the drastic dropping at the melting point under static conditions.

  14. Friction stir welding (FSW) of aluminium foam sandwich panels

    OpenAIRE

    M. Bušić; Kožuh, Z.; D. Klobčar; Samardžić, I.

    2016-01-01

    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 f...

  15. Performance of commercial aluminium alloys as anodes in gelled electrolyte aluminium-air batteries

    Science.gov (United States)

    Pino, M.; Chacón, J.; Fatás, E.; Ocón, P.

    2015-12-01

    The evaluation of commercial aluminium alloys, namely, Al2024, Al7475 and Al1085, for Al-air batteries is performed. Pure Al cladded Al2024 and Al7475 are also evaluated. Current rates from 0.8 mA cm-2 to 8.6 mA cm-2 are measured in a gel Al-air cell composed of the commercial alloy sample, a commercial air-cathode and an easily synthesizable gelled alkaline electrolyte. The influence of the alloying elements and the addition to the electrolyte of ZnO and ZnCl2, as corrosion inhibitors is studied and analysed via EDX/SEM. Specific capacities of up to 426 mAh/g are obtained with notably flat potential discharges of 1.3-1.4 V. The competition between self-corrosion and oxidation reactions is also discussed, as well as the influence of the current applied on that process. Al7475 is determined to have the best behaviour as anode in Al-air primary batteries, and cladding process is found to be an extra protection against corrosion at low current discharges. Conversely, Al1085 provided worse results because of an unfavourable metallic composition.

  16. TEM microstructure investigations of aluminium alloys used for laser alloying

    Directory of Open Access Journals (Sweden)

    K. Labisz

    2012-12-01

    Full Text Available Purpose: In this paper there are presented results of Transmission Electron Microscope investigation concerning the structure of the AlSi7Cu4 cast aluminium alloy using for alloying and remelting with the high power diode laser (HPDL. There are also presented the results of the thermo-derivative analysis performed using the UMSA (Universal Metallurgical Simulator and Analyser device, allowing to determine the specific points of the solidifying alloy, what is helpful for phase determination occurred in this alloy. In this work especially the changes of the precipitation type, size and shape were determined.Design/methodology/approach: The investigations were performed using electron microscopy for the microstructure and phases determination. By mind of the transmission electron microscopy, especially selected area diffraction method appliance it was possible to determine the phases occurred in the alloy in the as cast state. The morphology and size of the Mg2Si was also possible to determine as well the lattice parameters for this phase.Findings: : The reason of this work was also to present the laser treatment technology, which will be used for further alloying and remelting with ceramic powders – especially carbides and oxides. Particularly the overview will be directed on the laser power to achieve good layer hardness for protection of this hot work tool steel from losing their work stability and to make the tool surface more resistant to action in external conditions. The structure of the surface laser tray changes in a way, that there are very high roughness of the surface zone and the flatness or geometry changes in an important manner, crucial for further investigation.Research limitations/implications: The aluminium samples were examined metallographically using transmission electron microscope with different image techniques.Practical implications: Developing of new technology with appliance of Al alloys, High Power Diode Laser and

  17. 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....

  18. Stability of aluminium beams in case of fire

    NARCIS (Netherlands)

    Meulen, O.R. van der; Soetens, F.; Maljaars, J.

    2014-01-01

    Fire is often the dominant design criterion for aluminium structures. Present design rules for aluminium constructions in fire neglect both the decrease in susceptibility to local buckling and the effects of creep, that are intrinsic to aluminium. They may therefore either overestimate or underestim

  19. 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

  20. Qimingxing Aluminium of Jinma Group Ceases Production

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>Jinma Group announced on December 23 that its subsidiary Meishan Qimingxing Aluminium decided to cease production starting from De- cember 23,and that the company will keep a close eye to the market and will resume pro- duction once the market bounces back.In 2007, Jinma Group took over Meishan Qimingxing’s 40% share by 112 million yuan to enter the aluminium industry.Meishan Qimingxing’s assets include a 125,000-ton production line of aluminium and 168 300KA electrolytic baths. Affected by the state’s macro-regulation policy in early years,the company’s profit fell short of estimates.Net profit of Meishan Qimingxing in 2007 was 10.65 million yuan.

  1. Diamond grooving of rapidly solidified optical aluminium

    Science.gov (United States)

    Abou-El-Hossein, Khaled; Hsu, Wei-Yao; Ghobashy, Sameh; Cheng, Yuan-Chieh; Mkoko, Zwelinzima

    2015-10-01

    Traditional optical aluminium grades such as Al 6061 are intensively used for making optical components for applications ranging from mould insert fabrication to laser machine making. However, because of their irregular microstructure and relative inhomogeneity of material properties at micro scale, traditional optical aluminium may exhibit some difficulties when ultra-high precision diamond turned. Inhomogeneity and micro-variation in the material properties combined with uneven and coarse microstructure may cause unacceptable surface finish and accelerated tool wear, especially in grooving operation when the diamond tool edge is fully immersed in the material surface. Recently, new grades of optical aluminium that are featured by their ultra-fine microstructure and improved material properties have been developed to overcome the problem of high tool wear rates. The new aluminium grades have been developed using rapid solidification process which results in extremely small grain sizes combined with improved mechanical properties. The current study is concerned with investigating the performance of single-point diamond turning when grooving two grades of rapidly solidified aluminium (RSA) grades: RSA905 which is a high-alloyed aluminium grade and RSA443 which has a high silicon content. In this study, two series of experiments employed to create radial microgrooves on the two RSA grades. The surface roughness obtained on the groove surface is measured when different combinations of cutting parameters are used. Cutting speed is varied while feed rate and depth of cut were kept constant. The results show that groove surface roughness produced on RSA443 is higher than that obtained on RSA905. Also, the paper reports on the effect of cutting speed on surface roughness for each RSA grade.

  2. New aluminium alloys with high lithium content

    Energy Technology Data Exchange (ETDEWEB)

    Schemme, K.; Velten, B.

    1989-06-01

    Since the early 80's there have been made great efforts to replace the high strength aluminium alloys for the aircraft and space industry by a new generation of aluminium-lithium alloys. The attractivity of this kind of alloys could be increased by a further reduction of their density, caused by an increasing lithium content (/ge/ 5 wt.% Li). Therefore binary high-lithium containing alloys with low density are produced and metallografically investigated. A survey of their strength and wear behavior is given by using tensile tests and pin abrasing tests. (orig.).

  3. China’s Aluminium Consumption and the Related Policies

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    <正>China is a major aluminium consumer country in the world. In 2005, China produced 7.81 million tons aluminium and imported 640,000 tons. Meanwhile, China also exported 1.32 million tons aluminium in 2005. China’s apparent consumption of aluminium in 2005 was about 7.1 million tons, which was 9.3 times over that in 1990. China’s aluminium consumption growth has kept at an annual average of 16.1 per cent since 1990, which makes China the

  4. China’s Production and Market of Aluminium Extruded Profiles

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>Chinese aluminium extrusion industry came into existence at the early 1950s with most products used in military industry and national defence.At the beginning of 1980s,the produc- tion of construction aluminium profiles started simultaneously in North and South China.In the following thirty years,the aluminium extru- sion industry entered into a quickly developing stage with a focus on construction aluminium profiles.With the blooming real estate industry, the demand for construction aluminium profiles from the domestic market has a tendency of yearly increase.From 2000,the quick devel- opments of China’s auto and railway vehicle

  5. Plating on some difficult-to-plate metals and alloys

    International Nuclear Information System (INIS)

    Electrodeposition of coatings on metals such as beryllium, beryllium-copper, Kovar, lead, magnesium, thorium, titanium, tungsten, uranium, zirconium, and their alloys can be problematic. This is due in most cases to a natural oxide surface film that readily reforms after being removed. The procedures we recommend for plating on these metals rely on replacing the oxide film with a displacement coating, or etching to allow mechanical keying between the substrate and plated deposit. The effectiveness of the procedures is demonstrated by interface bond strengths found in ring-shear and conical-head tensile tests

  6. Measurements and modelling of residual stresses during quenching of thick heat treatable aluminium components in relation to their precipitation state

    OpenAIRE

    Chobaut, Nicolas

    2015-01-01

    In the fabrication of heat treatable aluminium parts, solutionising and quenching are key steps in order to obtain the required mechanical characteristics. Fast quenching is necessary to avoid coarse precipitation as this one reduces the mechanical properties after heat treatment. However fast quenching gives birth to high residual stresses, which cause unacceptable distortions during machining and can reduce service life drastically. For this reason, plates and forgings such as those conside...

  7. 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...

  8. The iron and cerium oxide influence on the electric conductivity and the corrosion resistance of anodized aluminium; A influencia do ferro e do oxido de cerio sobre a condutividade eletrica e a resistencia a corrosao do aluminio anodizado

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Kellie Provazi de

    2006-07-01

    The influence of different treatments on the aluminum system covered with aluminum oxide is investigated. The aluminum anodization in sulphuric media and in mixed sulphuric and phosphoric media was used to alter the corrosion resistance, thickness, coverage degree and microhardness of the anodic oxide. Iron electrodeposition inside the anodic oxide was used to change its electric conductivity and corrosion resistance. Direct and pulsed current were used for iron electrodeposition and the Fe(SO{sub 4}){sub 2}(NH{sub 4}){sub 2}.6H{sub 2}O electrolyte composition was changed with the addition of boric and ascorbic acids. To the sealing treatment the CeCl{sub 3} composition was varied. The energy dispersive x-ray (EDS), the x-ray fluorescence spectroscopy (FRX) and the morphologic analysis by scanning electronic microscopy (SEM) allowed to verify that, the pulsed current increase the iron content inside the anodic layer and that the use of the additives inhibits the iron oxidation. The chronopotentiometric curves obtained during iron electrodeposition indicated that the boric and ascorbic acids mixture increased the electrodeposition process efficiency. The electrochemical impedance spectroscopy (EIE), the Vickers (Hv) microhardness measurements and morphologic analysis evidenced that the sealing treatment improves the corrosion resistance of the anodic film modified with iron. The electrical impedance (EI) technique allowed to prove the electric conductivity increase of the anodized aluminum with iron electrodeposited even after the cerium low concentration treatment. Iron nanowires were prepared by using the anodic oxide pores as template. (author)

  9. Aluminium composite casting dispersion reinforced with iron-aluminium and silicon carbide phases

    OpenAIRE

    B. Formanek; J. Piątkowski; J. Szymszal

    2010-01-01

    Aluminium matrix composite with dispersion-reinforced, made by similar to stircasting process was characterised. The mixture of powders was produced by the process of mechanical agglomeration of powdered FexAly and SiC with aluminium. The chemical composition ofagglomerates was selected in a way such as to obtain 25 wt.% reinforcement of the AlSi9Cu4 silumin matrix. Applying thermal analysis ATD, the alloy solidification process was determined, reading out the typical solidification parameter...

  10. Natural gas anodes for aluminium electrolysis in molten fluorides.

    Science.gov (United States)

    Haarberg, Geir Martin; Khalaghi, Babak; Mokkelbost, Tommy

    2016-08-15

    Industrial primary production of aluminium has been developed and improved over more than 100 years. The molten salt electrolysis process is still suffering from low energy efficiency and considerable emissions of greenhouse gases (CO2 and PFC). A new concept has been suggested where methane is supplied through the anode so that the CO2 emissions may be reduced significantly, the PFC emissions may be eliminated and the energy consumption may decrease significantly. Porous carbon anodes made from different graphite grades were studied in controlled laboratory experiments. The anode potential, the anode carbon consumption and the level of HF gas above the electrolyte were measured during electrolysis. In some cases it was found that the methane oxidation was effectively participating in the anode process. PMID:27210046

  11. An unconventional set-up for fluxless brazing of aluminium

    CERN Document Server

    Loos, Robert

    1999-01-01

    In order to successfully braze aluminium alloy assemblies without the use of oxide-removing fluxes, an evironment with very low contaminant level is mandatory. This is mostly achieved by using a vacuum furnace. Brazing under inert gas of sufficient purity is also possible. The method reported upon here makes use of a stainless steel bag which can enter a traditional air furnace. The bag is evacuated, giving a well distributed mechanical pressure on the parts to join. The intrinsic handicap of poor vacuum is compensated by regular inert gas flushing, even at high temperatures. The set-up works rather well, and the idea is believed to yield a valuable strategic and economic option, for the realization of special equipment as well as for prototyping work. We intend to use the principle for the CMS Preshower cooling screens.

  12. Repassivation Investigations on Aluminium: Physical Chemistry of the Passive State

    Science.gov (United States)

    Nagy, Tristan Oliver; Weimerskirch, Morris Jhängi Joseph; Pacher, Ulrich; Kautek, Wolfgang

    2016-09-01

    We show the temporal change in repassivation mechanism as a time-dependent linear combination of a high-field model of oxide growth (HFM) and the point defect model (PDM). The observed switch in transient repassivation current-decrease under potentiostatic control occurs independently of the active electrode size and effective repassivation time for all applied overpotentials. For that, in situ depassivation of plasma electrolytically oxidized (PEO) coatings on aluminium was performed with nanosecond laser pulses at 266 nm and the repassivation current transients were recorded as a function of pulse number. A mathematical model combines the well established theories of oxide-film formation and growth kinetics, giving insight in the non linear transient behaviour of micro-defect passivation. According to our findings, the repassivation process can be described as a charge consumption via two concurrent channels. While the major current-decay at the very beginning of the fast healing oxide follows a point-defect type exponential damping, the HFM mechanism supersedes gradually, the longer the repassivation evolves. Furthermore, the material seems to reminisce former laser treatments via defects built-in during depassivation, leading to a higher charge contribution of the PDM mechanism at higher pulse numbers.

  13. Molecular breeding of cereals for aluminium resistance

    Science.gov (United States)

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

  14. Experimental analysis of cut welding in aluminium

    DEFF Research Database (Denmark)

    Dorph, Pernille; De Chiffre, Leonardo; Bay, Niels

    1993-01-01

    Cut welding is a newly developed cold pressure welding process. In the present work, an experimental investigation was carried out analyzing the mechanisms involved in cut welding of a block to a strip. Experiments were carried out in technically pure aluminium. The investigation has involved...

  15. Aluminium hydroxide-induced granulomas in pigs

    DEFF Research Database (Denmark)

    Valtulini, S; Macchi, C; Ballanti, P;

    2005-01-01

    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...

  16. 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.

  17. Microstructure Development during Solidification of Aluminium Alloys

    NARCIS (Netherlands)

    Ruvalcaba Jimenez, D.G.

    2009-01-01

    This Thesis demonstrates studies on microstructure development during the solidification of aluminium alloys. New insights of structure development are presented here. Experimental techniques such as quenching and in-situ High-brilliance X-ray microscopy were utilized to study the microstructure evo

  18. Failure of aluminium self-piercing rivets: An experimental and numerical study

    International Nuclear Information System (INIS)

    Highlights: ► We investigated the fracture mechanism of AA7278-T6 aluminium self-piercing rivets. ► Fracture of AA 7278-T6 rivets during the riveting process is a complex phenomenon. ► Microstructure of AA7278-T6 has significant influence on the fracture mechanism. ► Increasing friction will change the deformation mode of the rivet. - Abstract: The present paper investigates the fracture mechanisms of AA7278-T6 aluminium self-piercing rivets under compression during the riveting process. First, a microstructure investigation was conducted to disclose the grain structure and the particle distribution of the extruded aluminium alloy. Transmission electron micrographs revealed precipitate free zones along grain boundaries. Uniaxial tensile tests in three different directions with respect to the extrusion direction revealed anisotropy of the alloy in strength and ductility and a change in fracture mode with tensile direction. The behaviour of the alloy under compression was studied experimentally using upsetting tests and self-piercing riveting tests. Micrographs of the deformed specimens provided insight into the influence of the microstructure on the deformation and fracture of the alloy under compression. Second, numerical analyses were carried out using a 2-D axisymmetric model in LS–DYNA in an attempt to investigate the role of different physical variables on the final failure of the rivet. The numerical results revealed that constituent particles, precipitate free zones, and friction between the rivet and plates are important for strain localisation and fracture in the rivet

  19. Increased Zn/Glutathione Levels and Higher Superoxide Dismutase-1 Activity as Biomarkers of Oxidative Stress in Women with Long-Term Dental Amalgam Fillings: Correlation between Mercury/Aluminium Levels (in Hair) and Antioxidant Systems in Plasma

    OpenAIRE

    María Eugenia Cabaña-Muñoz; José María Parmigiani-Izquierdo; Luis Alberto Bravo-González; Hee-Moon Kyung; José Joaquín Merino

    2015-01-01

    Background The induction of oxidative stress by Hg can affect antioxidant enzymes. However, epidemiological studies have failed to establish clear association between dental fillings presence and health problems. Objectives To determine whether heavy metals (in hair), antioxidant enzymes (SOD-1) and glutathione levels could be affected by the chronic presence of heavy metals in women who had dental amalgam fillings. Materials and Methods 55 hair samples (42 females with amalgam fillings and 1...

  20. Aluminium EN AW-2124 alloy matrix composites reinforced with Ti(C,N), BN and Al2O3 particles

    International Nuclear Information System (INIS)

    Investigation results of the aluminium alloy EN AW-2124 matrix composite materials with particles of the powders Ti(C,N), BN and Al2O3 (15 wt.%) are presented in the paper. In order to obtain uniform distribution of reinforcement particles in aluminium alloy matrix powders of composite components have been milled in the rotary ball-bearing pulverizer. The composites have been pressed in laboratory vertical press at room temperature under the pressure of 500 kN. Obtained die samplings have been heated to the temperature 520-550 oC and extruded. Bars of diameter 8 mm have been received as a final product. Metallographic examination of the composites materials' structure shows non-uniform distribution of reinforced powders in the aluminium alloy matrix banding of reinforcements particles corresponds to the extrusion direction. Particles of reinforcement distribution in aluminium alloy matrix is irregular, some agglomerations of powder of aluminium oxide and porosity of different size have been noticed. Investigations of hardness and ultimate compressive strength show that the particles of reinforcement improve mechanical properties of composite materials. Investigations of compressive strength, carried out at room temperature, enable to compare mechanical properties of matrix and composite. (author)

  1. Evaluation of the Interface Between Two Plates by the Lamb Wave

    Institute of Scientific and Technical Information of China (English)

    王小民; 廉国选; 李明轩

    2001-01-01

    A new expression of the dispersion equation of the Lamb wave in an adhesive two-layered plate is presented. The bond rigidity of the adhesive plate is accounted for in terms of a spring model. The influence of the variations of the compliance constants of the spring on the dispersion feature of Lamb modes is numerically studied. The numerical results indicate that the deterioration of the bond rigidity may cause the phase velocity decrease and the frequency-shift for a given Lamb mode, thus having a possibility for the evaluation of the bonding state of the adhesive plate by using ultrasonic wave velocity measurements. The phase-tracing method is used to measure the phase velocities experimentally and the results for an adhesive plate of aluminium-aluminium are given to verify the theoretical predictions.

  2. Combined Effect of Buoyancy Force and Navier Slip on MHD Flow of a Nanofluid over a Convectively Heated Vertical Porous Plate

    Directory of Open Access Journals (Sweden)

    Winifred Nduku Mutuku-Njane

    2013-01-01

    Full Text Available We examine the effect of magnetic field on boundary layer flow of an incompressible electrically conducting water-based nanofluids past a convectively heated vertical porous plate with Navier slip boundary condition. A suitable similarity transformation is employed to reduce the governing partial differential equations into nonlinear ordinary differential equations, which are solved numerically by employing fourth-order Runge-Kutta with a shooting technique. Three different water-based nanofluids containing copper (Cu, aluminium oxide (Al2O3, and titanium dioxide (TiO2 are taken into consideration. Graphical results are presented and discussed quantitatively with respect to the influence of pertinent parameters, such as solid volume fraction of nanoparticles (φ, magnetic field parameter (Ha, buoyancy effect (Gr, Eckert number (Ec, suction/injection parameter (fw, Biot number (Bi, and slip parameter (β, on the dimensionless velocity, temperature, skin friction coefficient, and heat transfer rate.

  3. Combined effect of buoyancy force and Navier slip on MHD flow of a nanofluid over a convectively heated vertical porous plate.

    Science.gov (United States)

    Mutuku-Njane, Winifred Nduku; Makinde, Oluwole Daniel

    2013-01-01

    We examine the effect of magnetic field on boundary layer flow of an incompressible electrically conducting water-based nanofluids past a convectively heated vertical porous plate with Navier slip boundary condition. A suitable similarity transformation is employed to reduce the governing partial differential equations into nonlinear ordinary differential equations, which are solved numerically by employing fourth-order Runge-Kutta with a shooting technique. Three different water-based nanofluids containing copper (Cu), aluminium oxide (Al2O3), and titanium dioxide (TiO2) are taken into consideration. Graphical results are presented and discussed quantitatively with respect to the influence of pertinent parameters, such as solid volume fraction of nanoparticles (φ), magnetic field parameter (Ha), buoyancy effect (Gr), Eckert number (Ec), suction/injection parameter (f w ), Biot number (Bi), and slip parameter ( β ), on the dimensionless velocity, temperature, skin friction coefficient, and heat transfer rate. PMID:24222749

  4. First wall design of aluminium alloy R-tokamak

    International Nuclear Information System (INIS)

    A design study of a low-activation D-T tokamak Reacting Plasma Project In Nagoya has been finished. The study emphasizes the vacuum vessel and the bumper limiter. Our choice of materials (aluminium vacuum vessel, copper conductors, aluminium TF coil case and lead shield) results in a radiation level of about 1 x 10-3 times that of a TFTR type design, and 1 x 10-4 times that of JET type design, at 2 weeks after one D-T shot. Thick graphite tiles will be fixed directly on the aluminium vacuum vessel using aluminium spring washers and bolts. With this simplified structure of the bumper limiter, the inner surface temperature of the thick aluminium vacuum vessel will be less than 1200C which is required to reduce the overaging effect of the aluminium alloy. (orig.)

  5. 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?

  6. 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.

  7. 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 permeability were observed for any of the three diatoms suggesting that mechanisms of aluminium 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. PMID:26921729

  8. 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. PMID:25687835

  9. Straggling of heavy ions in aluminium

    International Nuclear Information System (INIS)

    An effort has been made to determine the straggling in aluminium of 4He, 16O and 35Cl ions of different energies produced by the tandem Van de Graaff at Harwell. The technique consists of scattering the accelerated and collimated ions in a scattering chamber from a 0.100 mg/cm2 gold foil, allowing the scattered ions to pass through a two aperture collimator, using different aluminium foils over one of the apertures and stopping the two emergent beams in a good quality silicon surface barrier detector the output of which is connected to a 4096 channel analyser. The energy widths obtained in the case of helium ions are in fair agreement with both the Bloch and the recent Tschalar (1968) theory. The measured widths in the case of heavy ions are very large and can be explained only if account is taken of their charge distributions in foils. This study should be useful in ion implantation work. (author)

  10. A low cost, light weight cenosphere–aluminium composite for brake disc application

    Indian Academy of Sciences (India)

    V Saravanan; P R Thyla; S R Balakrishnan

    2016-02-01

    The commonly used composite material for brake rotor consists of silicon carbide (SiC) or aluminium oxide (Al$_2$O$_3$) particles which are more expensive. The weight of conventionally used composite is more compared to base alloy. The aim of this paper is to develop a light weight material for brake disc applications thereby substituting base alloy and conventional composite. This analysis led to 10 vol% cenosphere reinforced aluminium alloy (AA) 6063 composite as the most appropriate material for brake disc. To ensure the manufacturability of composite, composite brake rotor was casted using the sand casting technique and was machined to achieve the final component. Thermal capability of brake disc was ensured by studying temperature variation through vehicle testing procedure of disc brake. Cost reduction is one of the important benefit acquired using cenosphere reinforced composite. This was ensured by cost estimation and analysis. The cost estimated to manufacture the AA6063 brake disc was compared with composite cost.

  11. China will Reduce Aluminium Export in 2005

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    <正>Starting from January 1, 2005, China eliminated the 8 per cent export tax rebate for aluminium, and further more, the exporters will have to pay 5 per cent export tax. This is beyond the expectations of the producers, for most of them thought only the 8 per cent export tax rebate would be eliminated and it was still too early to add the export tax.

  12. FSW characterization of 6082 aluminium alloys sheets

    OpenAIRE

    K. Mroczka; A. Pietras

    2009-01-01

    Purpose: The purpose of the investigations was to elaborate a set of FSW parameters for connecting 6082 aluminium alloy sheets allowing to produce welds of highest strength.Design/methodology/approach: The FSW was tried at different speeds and at additional cooling. The welds microstructure was studied using optical and scanning electron microscopes. The mechanical properties of produced connections are discussed regarding their tensile test and microhardness measurements.Findings: The FSW we...

  13. Methods of inoculation of pure aluminium structure

    Directory of Open Access Journals (Sweden)

    J. Szajnar

    2008-03-01

    Full Text Available Purpose: The main aim of investigations was the reduction of grain size and unification of structure for pure Al casting by introduction of small amount of inoculant (less than obligatory standart PN-EN 573-3, which concerning about aluminium purity, with electromagnetic field and variable casting parameters.Design/methodology/approach: To investigations it was used light microscopy and TEM. Surfaces of samples which were prepared for macro- and microstructure analysis were etched with use of solution of: 50g Cu, 400ml HCl, 300ml HNO3 and 300ml H2O. Thin foils for TEM investigations were electropolished with use of 20 ml HClO4 and 80ml CH3OH.Findings: The results of investigations and their analysis show possibility of effective inoculation of pure aluminium structure by use of some factors such as: different materials of the mould, influencing of stirring electromagnetic field into metal during solidification, inoculation by introducing AlTi5B1 inoculant into liquid aluminium and changing the pouring temperature.Research limitations/implications: I further research, authors of this paper are going to application of introduced method of inoculation in industrial tests.Practical implications: The work presents refinement of structure method which are particularly important in continuous and semi – continuous casting where products are used for plastic forming. Large columnar crystals zone result in forces extrusion rate reduction and during the ingot rolling delamination of external layers can occur. Thus, in some cases ingot skinning is needed, which rises the production costs.Originality/value: Contributes to research on size reduction in pure aluminium structure.

  14. Aluminium matrix composites fabricated by infiltration method

    OpenAIRE

    L.A. Dobrzański; M. Kremzer; A. J. Nowak; Nagel, A.

    2009-01-01

    Purpose: The aim of this work is to examine the structure and properties of metal matrix composites obtained by infiltration method of porous ceramic preforms by liquid aluminium alloy.Design/methodology/approach: Ceramic preforms were manufactured by the sintering method of ceramic powder. The preform material consists of powder Condea Al2O3 CL 2500, however, as the pore forming the carbon fibers Sigrafil C10 M250 UNS were used. Then ceramic preforms were infiltrated with liquid eutectic EN ...

  15. 铝及铝合金电刷镀银%Silver Brush Plating on Aluminium and Aluminium Alloys

    Institute of Scientific and Technical Information of China (English)

    姚恩静

    2001-01-01

    通过盐酸电解浸蚀法及电刷镀铜过渡,实现铝及铝合金上电刷镀银,确定铝及铝合金电刷镀银的一种刷镀工艺,提高了镀层耐腐蚀强度,得到了外观和结合力均良好的银镀层,同时增加镀铜层厚度 ,相对减少镀银层厚度,不影响其它指标,节省了镀银药液,降低了成本,并在实际生产中得到了验证.

  16. Softening Behaviour of Selected Commercially Pure Aluminium Model Alloys

    OpenAIRE

    Sande, Gunnar

    2012-01-01

    A characterization of the softening behaviour of four different commercially pure aluminium alloys has been carried out. The work is related to the MOREAL project (Modelling towards value-added recycling friendly aluminium alloys), where the main goal is to quantify the effect of the elements in recyclable aluminium alloys on microstructure and mechanical properties during thermo-mechanical processing. Typical elements are iron (Fe), silicon (Si) and manganese (Mn), and the alloys studied in ...

  17. Un-optimistic Prospects for the Westward Movement of Aluminium

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>The westward movement of aluminium is essential for the industrial development.Up till now,the northwestern area has planned to construct more than 40 aluminium projects with a total production capacity of over 20 million tons.The future rate of progress of newly constructed projects are directly related to the supplies of the aluminium market,having critical guiding meaning for the trends of

  18. Friction factor of CP aluminium and aluminium–zinc alloys

    Indian Academy of Sciences (India)

    N Vidhya Sagar; K S Anand; A C Mithun; K Srinivasan

    2006-12-01

    Friction factor has been determined for CP aluminium and aluminium–zinc alloys using ring compression test at different temperatures from 303 K to 773 K. It is found that CP aluminium exhibits sticking whereas Al–Zn alloys do not exhibit sticking at elevated temperatures. Hot working of Al–Zn alloy is easier than that of CP aluminium at 773 K. As zinc content increases up to 10 wt% the friction factor decreases up to 0.02.

  19. Aluminium supplier selection for the automotive parts manufacturer

    OpenAIRE

    M. Cieśla

    2016-01-01

    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 an...

  20. 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

  1. Tribological characteristics of coatings on aluminium and its alloys

    OpenAIRE

    Abdul-Mahdi, Fadhil S

    1987-01-01

    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University. Hard anodising on aluminium and its alloys has been widely practised for many years in order to improve the resistance of the otherwise poor wear characteristics of aluminium. In recent years there has been an increasing interest in other treatments and coatings, on both aluminium and other base metals. The aim of this investigation is to explain the tribological performance and wear mechanis...

  2. Behaviour and design of aluminium alloy structural elements

    OpenAIRE

    Su, Meini; 蘇玫妮

    2014-01-01

    Aluminium alloys are nonlinear metallic materials with continuous stress-strain curves that are not well represented by the simplified elastic, perfectly plastic material model used in most existing design specifications. The aims of this study are to develop a more efficient design method for aluminium alloy structures by rationally exploiting strain hardening. The key components of this study include laboratory testing, numerical modelling and development of design guidance for aluminium al...

  3. 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.)

  4. Aluminium in the rail transportation market

    Energy Technology Data Exchange (ETDEWEB)

    Zehnder, J. [Alcan Alesa Engineering Ltd., Zurich (Switzerland). Alcan Mass Transportation Systems

    2002-07-01

    Rail-transportation is not, as one might expect, a homogeneous market but extremely fragmented and even with huge differences from continent to continent, i.e. in North America freight transport is dominating whereas in Europe passenger transport prevails. A first segmentation splits infrastructure from vehicles. In a second layer of segmentation we distinguish between light rail vehicles, heavy metros, regional trains, intercity trains, high speed trains with and without tilting, maglev trains, freight vehicles and locomotives. Finally, we find aluminium applications in wheels, suspension parts, brake equipment, traction equipment, body structure, hang on parts and interior trim. On the infrastructure side best use of aluminium is in the field of power supply. In order to have the best solution for each application, all forms of products such as castings, forgings, flat rolled products and extrusions are needed and the engineers are using a broad choice or different alloys for all the requirements such as structural strength, decorative aspect, electrical conductivity, wear resistance, weldability, corrosion resistance etc. Innovation cycles in rail transportation are very slow, mainly because the expected life of vehicles is over 30 years and so no fleet owner will run the risk of getting vehicles with non-proven components, i.e. where a safe life of over 30 years cannot be shown. In the following the most important aluminium applications are shown and discussed. (orig.)

  5. Plasmonic enhancement of photoluminescence from aluminium nitride

    Science.gov (United States)

    Flynn, Chris; Stewart, Matthew

    2016-03-01

    Aluminium nitride (AlN) films were grown on c-plane sapphire wafers by molecular beam epitaxy (MBE) under aluminium-rich conditions. The excess aluminium (Al) accumulated on the surface of the films as micro-scale droplets 1-10 μm in size, and as Al nanoparticles with diameters in the range 10-110 nm. Photoluminescence (PL) measurements were performed on the AlN samples using a 193 nm Excimer laser as the excitation source. Prior to PL measurements the wafers were cleaved in half. One half of each wafer was submitted to a 10 min treatment in H3PO4 heated to 70 °C to remove the excess Al from the film surface. The remaining half was left in the as-deposited condition. The mean intensities of the near-band-edge PL peaks of the as-deposited samples were 2.0-3.4 times higher compared to the samples subjected to the H3PO4 Al-removal treatment. This observation motivated calculations to determine the optimal Al surface nanosphere size for plasmonic enhancement of PL from AlN. The PL enhancement was found to peak for an Al nanosphere radius of 15 nm, which is within the range of the experimentally-observed Al nanoparticle sizes.

  6. Effect of Coupon Orientation on Corrosion Behaviour of Aluminium Alloy Coupons in the Spent Fuel Storage Section of the IEA-R1 Research Reactor

    International Nuclear Information System (INIS)

    Surveillance programmes to monitor the corrosion of aluminium clad spent research reactor fuels have used test racks containing horizontal metallic coupons. Spent MTR-type fuel elements are usually stored vertically, with their fuel plates, also vertical. Hence, the influence of coupon orientation on the corrosion behaviour of aluminium alloy coupons exposed to the spent fuel storage section of the IEA-R1 research reactor in Sao Paulo, Brazil, has been studied. Circular coupons of aluminium alloys AA 1050 and AA 6061, oriented both vertically and horizontally, were exposed to the storage section water for a year. Individual and coupled coupons were exposed to simulate general, crevice and galvanic corrosion. The storage section water parameters were periodically measured. Pitting was the main form of corrosion and coupon orientation had a marked effect on the extent of pitting. Vertically oriented coupons pitted less than horizontally oriented coupons. (author)

  7. Laser beam welding of high strength aluminium-lithium alloys; Laserstrahlschweissen von hochfesten Aluminium-Lithium Legierungen

    Energy Technology Data Exchange (ETDEWEB)

    Enz, Josephin

    2012-07-01

    The present development in aircraft industry determined by the demand for a higher cost-effectiveness. Laser beam welding is one of the most promising joining technologies for the application in the aircraft industry through the considerable reduction of the production costs. Furthermore the weight of an aircraft structure can be reduced by the use of light and high strength aluminium alloys. This paper deals with the development of a process for the laser beam welding of a skin-stringer-joint where the Al-Li-alloy AA2196 is used as stringer material and the Al-Li-alloy AA2198 is used as skin and stringer material. By the use of design of experiments the optimal welding process parameters for different material combinations were determined which will be used for the welding of a 5-stringer panel. Therefore the weld seams of the joints were tested for irregularities and microstructural characteristics. In addition several mechanical tests were performed, which define the quality of the welded joint. Furthermore the influence of the oxide layer and the welding preparation on the welding performance was investigated. (orig.) [German] Die derzeitigen Entwicklungen im Flugzeugbau werden durch die allgemeine Forderung nach einer Steigerung der Wirtschaftlichkeit bestimmt. Das Laserstrahlschweissen ist dabei eines der vielversprechendsten Fuegeverfahren fuer die Anwendung im Flugzeugbau durch das die Herstellungskosten deutlich reduziert werden koennen. Zudem kann durch die Verwendung von leichten und hochfesten Aluminium-Legierungen das Gewicht einer Flugzeugstruktur zusaetzlich reduziert werden. Die vorliegende Arbeit befasst sich mit der Entwicklung eines Prozesses zum Laserstrahlschweissen einer Skin-Stringer-Verbindung aus den Aluminium-Lithium-Legierungen AA2196 (als Stringer-Werkstoff) und AA2198 (als Skin- und Stringer-Werkstoff). Unter Verwendung der statistischen Versuchsplanung wurden die optimalen Einstellungen der Schweissprozessparameter fuer die

  8. Aluminium composite casting dispersion reinforced with iron-aluminium and silicon carbide phases

    Directory of Open Access Journals (Sweden)

    B. Formanek

    2010-10-01

    Full Text Available Aluminium matrix composite with dispersion-reinforced, made by similar to stircasting process was characterised. The mixture of powders was produced by the process of mechanical agglomeration of powdered FexAly and SiC with aluminium. The chemical composition ofagglomerates was selected in a way such as to obtain 25 wt.% reinforcement of the AlSi9Cu4 silumin matrix. Applying thermal analysis ATD, the alloy solidification process was determined, reading out the typical solidification parameters. The methods of light and scanning microscopy were used to reveal the structure of composite casting. Changes in chemical composition and phase composition of particles of the FeAl intermetallic phase in aluminium matrix were confirmed. The structure of silumin casting with matrix containing microregions of ceramic and intermetallic phases, typical of hybrid reinforcements, was obtained.

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

    Indian Academy of Sciences (India)

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

    2000-08-01

    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 from the sulfate. This contains a higher concentration of anionic impurities related to differences in the solubility of the original aluminium salts. The sulfate is retained in the gel to higher temperatures at which its eventual decomposition may lead to the formation of a reactive pore structure which facilitates the nucleation of -Al2O3.

  10. Synthesis of aluminium nanoparticles by arc evaporation of an aluminium cathode surface

    Indian Academy of Sciences (India)

    M Gazanfari; M Karimzadeh; S Ghorbani; M R Sadeghi; G Azizi; H Karimi; N Fattahi; Z Karimzadeh

    2014-06-01

    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 nanoparticles was performed immediately. The effects of media on the yield and morphology of aluminium nanoparticles were investigated. Analysis result of the samples indicated that particle size was less than 30 nm, when 120 A/cm2 arc current was used. In addition, coating agent can affect arc velocity, arc stability, morphology and composition of the nanoparticles. Resultant nanoparticles were identified using X-ray powder diffraction (XRD), also their surface morphology was studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) and finally the accuracy of coating was assessed with infrared (IR) spectroscopy.

  11. Synthesis of aluminium nanoparticles by arc plasma spray under atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Mandilas, Charalampos; Daskalos, Emmanouil [Aerosol and Particle Technology Laboratory (APTL), Chemical Process and Energy Resources Institute, Centre for Research and Technology-Hellas (CERTH/CPERI), P.O. Box 361, 57001 Thermi, Thessaloniki (Greece); Karagiannakis, George, E-mail: gkarag@cperi.certh.gr [Aerosol and Particle Technology Laboratory (APTL), Chemical Process and Energy Resources Institute, Centre for Research and Technology-Hellas (CERTH/CPERI), P.O. Box 361, 57001 Thermi, Thessaloniki (Greece); Konstandopoulos, Athanasios G., E-mail: agk@cperi.certh.gr [Aerosol and Particle Technology Laboratory (APTL), Chemical Process and Energy Resources Institute, Centre for Research and Technology-Hellas (CERTH/CPERI), P.O. Box 361, 57001 Thermi, Thessaloniki (Greece); Department of Chemical Engineering, Aristotle University, P.O. Box 1517, 54006 Thessaloniki (Greece)

    2013-01-01

    Highlights: Black-Right-Pointing-Pointer A customized arc-plasma spraying based system has been designed and implemented. Black-Right-Pointing-Pointer The system is relatively simple, robust and operates at atmospheric pressure. Black-Right-Pointing-Pointer Preparation of aluminium nanoparticles from micron-sized powder was successful. Black-Right-Pointing-Pointer Various nano-sized distributions were possible depending on operating parameters. Black-Right-Pointing-Pointer Optimization of the proposed design will lead to higher efficiencies and throughput. - Abstract: The present study addresses the feasibility to synthesize aluminium nanoparticles (NPs) from micron-sized aluminium powder with the use of a customized atmospheric plasma spraying (APS) technique. Using APS, nanoparticle synthesis can be achieved via rapid melting and vaporization of the initial micrometric particles and their subsequent re-nucleation. A custom mantle system was designed and developed with the aid of relevant simplified CFD simulations. The mantle provided the necessary inert environment (argon), at ambient pressure, in order to avoid any oxidation of the metal during plasma spraying while promoted rapid quenching of the gasified metal. The particles formed were collected with the aid of a quartz filter downstream of the plasma flame and the production rate achieved was 2 g min{sup -1}. Ex situ post-characterization of the particles via X-ray diffraction, specific surface area measurement (BET), transmission electron microscopy (TEM) coupled with energy dispersive spectrometry (EDS) and thermogravimetric analysis (TGA) under air revealed that the powders obtained primarily comprised of monocrystalline metallic aluminium nanoparticles of almost spherical shape. The NPs possessed a 2-5 nm oxide coating layer. By regulating the conditions inside the mantle, a variety of different size distributions were obtained.

  12. Lipid peroxidation as pathway of aluminium cytotoxicity in human skin fibroblast cultures: prevention by superoxide dismutase+catalase and vitamins E and C.

    Science.gov (United States)

    Anane, R; Creppy, E E

    2001-09-01

    Lipid peroxidation is one of the main manifestations of oxidative damage and has been found to play an important role in the toxicity and carcinogenicity of many xenobiotics. In the present study, we investigated the possible induction of lipid peroxidation by aluminium in human foreskin fibroblast cultures by assaying the malondialdehyde (MDA) produced inside the cells. The MDA-thiobarbituric acid (TBA) adduct was assayed by HPLC using fluorometric quantification after extraction in n-butanol. Lactate dehydrogenase (LDH) release was used as a marker of aluminium toxicity. MDA production was significantly increased after 24 h incubation with aluminium and paralleled LDH release. Superoxide dismutase (SOD)+catalase and vitamins C and E added in the culture medium as oxygen radical and free radical scavengers were efficient in preventing MDA production by aluminium, indicating that oxidative processes are one of the main pathways whereby this metal induces cytotoxicity. The latter is also largely prevented, thus confirming the link between oxidative stress induced by aluminium and its cytotoxicity in human skin fibroblasts.

  13. Cold-impregnated aluminium. A new source of nickel exposure.

    Science.gov (United States)

    Lidén, C

    1994-07-01

    A new technique for finishing anodized aluminium was introduced during the 1980s--cold impregnation with nickel. Nickel is available on the surface of cold-impregnated aluminium, as shown by the dimethylglyoxime test. Chemical analysis with EDXA showed that nickel was in the form of NiSO4. A case of work-related allergic contact dermatitis in an engraver with nickel allergy is reported. It transpired that the patient was exposed to nickel in connection with aluminium. It is concluded that cold-impregnated aluminium is a new source of nickel exposure, probably previously unknown to dermatologists. PMID:7924288

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

    Science.gov (United States)

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

    2014-03-01

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

  15. 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.

  16. Aluminium anode for biogalvanic metal--oxygen -cells

    Energy Technology Data Exchange (ETDEWEB)

    Weidlich, E.

    1975-02-20

    The invention deals with an aluminium anode for biogalvanic metal--oxygen cells. The object of the invention is to improve further an aluminium anode for biogalvanic metal--oxygen cells. In particular, the lifetime is to be increased and the Faraday degree of efficiency is to be improved by suppressing an excessive hydrogen development. The anode is thus constructed so as to have a metal net on both sides with aluminium layers, and the surfaces of the aluminium layers not facing the metal net are lapped or sand-blasted and have an anodized layer on their boundary regions.

  17. Negative aluminium electrode for biogalvanic metal-oxygen cells

    Energy Technology Data Exchange (ETDEWEB)

    Weidlich, E.

    1977-03-24

    The invention deals with an aluminium anode for biogalvanic metal-oxygen cells. The object of the invention is to further improve an aluminium anode for biogalvanic metal-oxygen cells. In particular, the service life is to be increased and the Faraday degree of efficiency is to be improved, by suppressing an excessive hydrogen development. The anode is thus constructed so as to have a metal net on both sides with aluminium layers and the surfaces of the aluminium layers not facing the metal net are lapped or sand-blasted and have an eloxal layer on their boundary regions.

  18. Effects of thermal stratification on transient free convective flow of a nanofluid past a vertical plate

    Indian Academy of Sciences (India)

    NIRMAL CHAND PEDDISETTY

    2016-10-01

    An analysis of thermal stratification in a transient free convection of nanofluids past an isothermal vertical plate is performed. Nanofluids containing nanoparticles of aluminium oxide, copper, titanium oxide and silver having volume fraction of the nanoparticles less than or equal to 0.04 with water as the base fluid are considered. The governing boundary layer equations are solved numerically. Thermal stratification effects and volume fraction of the nanoparticles on the velocity and temperature are represented graphically. It is observed that an increase in the thermal stratification parameter decreases the velocity and temperature profiles of nanofluids. An increase in the volume fraction of the nanoparticles enhances the temperature and reduces the velocity of nanofluids. Also, the influence of thermal stratification parameter and the volume fraction of the nanoparticles of local as well as average skin friction and the rate of heat transfer of nanofluids are discussed and represented graphically.The results are found to be in good agreement with the existing results in literature.

  19. Optimisation of the rivet joints of the CFRP composite material and aluminium alloy

    Directory of Open Access Journals (Sweden)

    A. Czulak

    2007-01-01

    Full Text Available Purpose: The project included analysis of strain, cracking, and failure of riveted joints of plate elements madefrom the carbon-fibre-reinforced plastics (CFRP and from the 6061 aluminium alloy.Design/methodology/approach: The modelled static tensile strength test carried out for the plates from CFRPand from the 6061 aluminium alloy joined with the steel rivet. Computer simulation was carried out with IDEASsoftware package employing the FEM.Findings: Simulations using the mesh with a bigger number of FEM elements do not yield better accuracy ofcalculations and do not improve convergence with the results of laboratory experiments. Only the calculationtime gets longer. Computer simulation has also show that the type of contacts employed between elementsaffects the results significantly.Research limitations/implications: For the composite materials, joints between materials and computersimulation examinations are planed.Practical implications: Results obtained for the mesh with 4 and 5 FEM elements are the closest to the resultsof laboratory experiments, which is confirmed by the strain plot. Simulations using the mesh with a biggernumber of FEM elements do not yield better accuracy of calculations and do not improve convergence with theresults of laboratory experiments. Only the calculation time gets longer. Computer simulation has show that thetype of contacts employed between elements affects the results significantly.Originality/value: The paper presents influence of fibre mesh closeness on convergence of the results with laboratorytests. Simulation results were collected and compared with the laboratory static tensile strength tests results.

  20. Investigation and in situ removal of spatter generated during laser ablation of aluminium composites

    Science.gov (United States)

    Popescu, A. C.; Delval, C.; Shadman, S.; Leparoux, M.

    2016-08-01

    Spatter generated during laser irradiation of an aluminium alloy nanocomposite (AlMg5 reinforced with Al2O3 nanoparticles) was monitored by high speed imaging. Droplets trajectory and speed were assessed by computerized image analysis. The effects of laser peak power and laser focusing on the plume expansion and expulsed droplet speeds were studied in air or under argon flow. It was found that the velocity of visible droplets expulsed laterally or at the end of the plume emission from the metal surface was not dependent on the plasma plume speed. The neighbouring area of irradiation sites was studied by optical and scanning electron microscopy. Droplets deposited on the surface were classified according to their size and counted using a digital image processing software. It was observed that the number of droplets on surface was 1.5-3 times higher when the laser beam was focused in depth as compared to focused beams, even though the populations average diameter were comparable. Three methods were selected for removing droplets in situ, during plume expansion: an argon gas jet crossing the plasma plume, a fused silica plate collector transparent to the laser wavelength placed parallel to the irradiated surface and a mask placed onto the aluminium composite surface. The argon gas jet was efficient only for low power irradiation conditions, the fused silica plate failed in all tested conditions and the mask was successful for all irradiation regimes.

  1. Strengthening of aluminium by a three-dimensional network of aluminium-oxide particles

    DEFF Research Database (Denmark)

    Hansen, Niels

    1969-01-01

    Study of transmission electron microscopy and tensile testing at room temperature and 400 C show that a network of hard particles strengthens aluminum effectively almost as much as a uniform dispersion of particles. An equation is derived for a relationship between the tensile stress and the mesh...

  2. 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

  3. 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.

  4. Modifications study of the electronic structure of silicon oxides (α-SiO2), aluminium oxides (α-Al2O3) and yttrium oxides (Y2O3), induced by structural defects (non-stoichiometry, mechanical strains, high energy ions irradiation)

    International Nuclear Information System (INIS)

    Structure defects effects on electronic structure were studied experimentally (X absorption spectroscopy and photoelectron spectroscopy) and theoretically (state density calculus based on high binding strengths). This thesis is divided into three parts: oxygen stoichiometry effect on yttrium oxide (Y2O3) electronic structure, mechanical strain effect on quartz-α (SiO2) electronic structure, high energy ions irradiation effects on quartz-α. (A.B.). refs., figs., tabs

  5. Increased Zn/Glutathione Levels and Higher Superoxide Dismutase-1 Activity as Biomarkers of Oxidative Stress in Women with Long-Term Dental Amalgam Fillings: Correlation between Mercury/Aluminium Levels (in Hair) and Antioxidant Systems in Plasma

    Science.gov (United States)

    Cabaña-Muñoz, María Eugenia; Parmigiani-Izquierdo, José María; Bravo-González, Luis Alberto; Kyung, Hee-Moon; Merino, José Joaquín

    2015-01-01

    Background The induction of oxidative stress by Hg can affect antioxidant enzymes. However, epidemiological studies have failed to establish clear association between dental fillings presence and health problems. Objectives To determine whether heavy metals (in hair), antioxidant enzymes (SOD-1) and glutathione levels could be affected by the chronic presence of heavy metals in women who had dental amalgam fillings. Materials and Methods 55 hair samples (42 females with amalgam fillings and 13 female control subjects) were obtained. All subjects (mean age 44 years) who had dental amalgam filling for more than 10 years (average 15 years). Certain metals were quantified by ICP-MS (Mass Spectrophotometry) in hair (μg/g: Al, Hg, Ba, Ag, Sb, As, Be, Bi, Cd, Pb, Pt, Tl, Th, U, Ni, Sn, Ti) and SOD-1 and Glutathione (reduced form) levels in plasma. Data were compared with controls without amalgams, and analyzed to identify any significant relation between metals and the total number of amalgam fillings, comparing those with four or less (n = 27) with those with more than four (n = 15). As no significant differences were detected, the two groups were pooled (Amlgam; n = 42). Findings Hg, Ag, Al and Ba were higher in the amalgam group but without significant differences for most of the heavy metals analyzed. Increased SOD-1 activity and glutathione levels (reduced form) were observed in the amalgam group. Aluminum (Al) correlated with glutathione levels while Hg levels correlated with SOD-1. The observed Al/glutathione and Hg/SOD-1 correlation could be adaptive responses against the chronic presence of mercury. Conclusions Hg, Ag, Al and Ba levels increased in women who had dental amalgam fillings for long periods. Al correlated with glutathione, and Hg with SOD-1. SOD-1 may be a possible biomarker for assessing chronic Hg toxicity. PMID:26076368

  6. Gas heat treatment plants for the aluminium industry; Gasbeheizte Waermebehandlungsanlagen fuer die Aluminium-Industrie

    Energy Technology Data Exchange (ETDEWEB)

    Olberts, P.; Hanus, A. [LOI Thermprocess GmbH, Essen (Germany)

    2004-09-01

    LOI Thermoprocess has developed new, flexible, innovative furnace designs for heat treatment of aluminium in general (car industry) and particularly for cylinder heads, engine units, chassis components, textured components, wheels, rolled sheet and extrusions. The furnaces are heated by means of radiant tubes (recuperators) and by the more usual open gas heating system (flue gas recirculation). (orig.)

  7. The aluminium body has been promoted in Canada; La carrosserie aluminium promue au Canada

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2004-02-01

    The aluminium vehicles technology is a technology which allows, with an equivalent structure, to decrease the weight of a car of 40%. Presented by the Alcan firm, this technology is one of the technologies of the year 2003. The Alcan firm has, besides, received the 2003 technology price awarded by the magazine Industry Week. (O.M.)

  8. Create Your Plate

    Medline Plus

    Full Text Available ... plates! Snap a photo and share it to social media with #CreateYourPlate . See the full gallery of submitted plates! * ... Insurance For Parents & Kids Know Your Rights We Can ...

  9. Create Your Plate

    Medline Plus

    Full Text Available ... deaths a year than breast cancer and AIDS combined. Your gift today will help us get closer ... Plate! Click on the plate sections below to add your food choices. Reset Plate Share Create Your ...

  10. Combined Corrosion and Wear of Aluminium Alloy 7075-T6

    NARCIS (Netherlands)

    Liu, Y.; Mol, J.M.C.; Janssen, G.C.A.M.

    2016-01-01

    The aluminium alloy 7075-T6 is widely used in engineering. In some applications, like slurry transport, corrosion and abrasion occur simultaneously, resulting in early material failure. In the present work, we investigated the combined effect of corrosion and wear on the aluminium alloy 7075-T6. We

  11. 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.

  12. New Policies to Control the Aluminium Industry Expansion

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    <正>Information from China Nonferrous Metals Industry Association (CNIA) shows that new government policies on China’s aluminium industry will be released soon in order to control the rapid expansion of the aluminium industry which consumes large amount of power resources. Based on the new policies, investors of

  13. Chalco Calls for End of More Control Measures on Aluminium

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    <正> To control the investment rush in electrolyticaluminium in recent years and ensure thehealthy development of China’s aluminium in-dustry, the State Council recently released aseries of adjustment policies and control meas-ures,which effectively prevented theinvestment rush and limited the aluminium out-put growth.

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

    OpenAIRE

    Buchanan, Malcolm RC; Ihle, Benno U; Dunn, Cheryl M

    1981-01-01

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

  15. Developments in finite element simulations of aluminium extrusion

    NARCIS (Netherlands)

    Lof, Joeri

    2000-01-01

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

  16. CAD implementation of design rules for aluminium extrusion dies

    NARCIS (Netherlands)

    Ouwerkerk, van Gijs

    2009-01-01

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

  17. Enhanced corrosion protection by microstructural control of aluminium brazing sheet

    NARCIS (Netherlands)

    Norouzi Afshar, F.

    2013-01-01

    Aluminium brazing sheet is a sandwich material made out of two aluminium alloys (AA4xxx/AA3xxx) and is widely used in automotive heat exchangers. One of the main performance criteria for heat exchanger units is the lifetime of the product. The lifetime of the heat exchanger units is determined by th

  18. Surface formation in direct chill (DC) casting of 6082 aluminium alloys

    Science.gov (United States)

    Bayat, N.; Carlberg, T.

    2016-03-01

    Surface defects in aluminium billet production are a real problem for the subsequent extrusion procedure. Extrusion productivity can be influenced by the surface properties, which is defined as surface appearance, surface segregation zone depth and large Mg2Si and β-particles (Al5FeSi). In this research the surface formation during DC casting of 6082 aluminium billets produced by the air slip technology is studied. The surface microstructures of 6082 aluminium alloys with smooth and wavy surface appearances were investigated, including segregation zone depths and phase formation. The results were discussed based on the exudation of liquid metal through the mushy zone. The specific appearance of the wavy surface of 6082 alloys was correlated to how the oxide skin adheres to the underlying mushy zone and coupled to the dendritic coherency and surface tension of the skin. The occurrence of different phases at the very surface and in the layer just below was explained by variations in solidification directions and subsequent segregation patterns.

  19. ECAP – New consolidation method for production of aluminium matrix composites with ceramic reinforcement

    Directory of Open Access Journals (Sweden)

    Mateja Šnajdar Musa

    2013-06-01

    Full Text Available Aluminium based metal matrix composites are rapidly developing group of materials due to their unique combination of properties that include low weight, elevated strength, improved wear and corrosion resistance and relatively good ductility. This combination of properties is a result of mixing two groups of materials with rather different properties with aluminium as ductile matrix and different oxides and carbides added as reinforcement. Al2O3, SiC and ZrO2 are the most popular choices of reinforcement material. One of the most common methods for producing this type of metal matrix composites is powder metallurgy since it has many variations and also is relatively low-cost method. Many different techniques of compacting aluminium and ceramic powders have been previously investigated. Among those techniques equal channel angular pressing (ECAP stands out due to its beneficial influence on the main problem that arises during powder compaction and that is a non-uniform distribution of reinforcement particles. This paper gives an overview on ECAP method principles, advantages and produced powder composite properties.

  20. Influence of aluminium incorporation on the structure of ZrN films deposited at low temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Araiza, J J [Unidad Academica de Fisica, Universidad Autonoma de Zacatecas, Paseo a la Bufa esq, Calzada Solidaridad s/n 98060, Zacatecas (Mexico); Sanchez, O [Departamento de Fisica e Ingenieria de Superficies, Instituto de Ciencia de Materiales de Madrid-CSIC, C/ Sor Juana Ines de la Cruz 3, 28049 Cantoblanco, Madrid (Spain)], E-mail: olgas@icmm.csic.es

    2009-06-07

    We have studied the influence of Al incorporation in the crystalline structure of ZrN thin films deposited by dc magnetron sputtering at low temperature. The amount of aluminium in the films depends directly on the power applied to the aluminium cathode during the deposition. Energy dispersive x-ray analysis and x-ray diffraction (XRD) were used to obtain the chemical composition and crystalline structure of the films, respectively. When Al atoms are incorporated into the ZrN coatings, the strong ZrN (2 0 0) orientation is modified by a combination of other ones such as ZrN (1 1 1), Zr{sub 3}N{sub 4} (2 1 1) and hexagonal AlN (1 0 0) as detected from the XRD spectra for high aluminium concentrations. Fourier-transform infrared spectroscopy allowed us to identify oxides and nitrides, ZrO, AlO and AlN, incorporated into the deposited films. The effect of a bias voltage applied to the substrate has also been investigated and related to the changes in the microstructure and in the nanohardness values of the ZrAlN films.

  1. New sheet aluminium qualities for low-cost lightweight constructions; Neue Aluminium-Blechqualitaeten fuer den kosteneffizienten Leichtbau

    Energy Technology Data Exchange (ETDEWEB)

    Bloeck, M.; Furrer, P. [Novelis Technology AG, Neuhausen (Switzerland)

    2005-11-01

    Aluminium alloys used for car bodies have a wide range of material characteristics. New developments focus on selective development of material and surface characteristics for obtaining sheet aluminium qualities optimized for specific applications. These and further measures taken by Novelis are to reduce material consumption, simplify process steps in motor car manufacturing and reducing the overall system cost. (orig.)

  2. Design of the lines of aluminium drawing. Part 2; Conception des filieres de filage d'aluminium. Partie 2

    Energy Technology Data Exchange (ETDEWEB)

    Cescutti, J.P.; Ravaille, N. [Pechiney, Div. Filiage, 75 - Paris (France)

    2005-12-15

    This work is the second part of the file 'design of the lines of aluminium drawing'. It gives elements for structuring the analysis of the progress ways in the field of the design of the lines of aluminium extrusion. (O.M.)

  3. Aluminium matrix composites: Challenges and opportunities

    Indian Academy of Sciences (India)

    M K Surappa

    2003-02-01

    Aluminium matrix composites (AMCs) refer to the class of light weight high performance aluminium centric material systems. The reinforcement in AMCs could be in the form of continuous/discontinuous fibres, whisker or particulates, in volume fractions ranging from a few percent to 70%. Properties of AMCs can be tailored to the demands of different industrial applications by suitable combinations of matrix, reinforcement and processing route. Presently several grades of AMCs are manufactured by different routes. Three decades of intensive research have provided a wealth of new scientific knowledge on the intrinsic and extrinsic effects of ceramic reinforcement vis-a-vis physical, mechanical, thermo-mechanical and tribological properties of AMCs. In the last few years, AMCs have been utilised in high-tech structural and functional applications including aerospace, defence, automotive, and thermal management areas, as well as in sports and recreation. It is interesting to note that research on particle-reinforced cast AMCs took root in India during the 70’s, attained industrial maturity in the developed world and is currently in the process of joining the mainstream of materials. This paper presents an overview of AMC material systems on aspects relating to processing, microstructure, properties and applications.

  4. Reactions on carbon anodes in aluminium electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Eidet, Trygve

    1997-12-31

    The consumption of carbon anodes and energy in aluminium electrolysis is higher than what is required theoretically. This thesis studies the most important of the reactions that consume anode materials. These reactions are the electrochemical anode reaction and the airburn and carboxy reactions. The first part of the thesis deals with the kinetics and mechanism of the electrochemical anode reaction using electrochemical impedance spectroscopy. The second part deals with air and carboxy reactivity of carbon anodes and studies the effects of inorganic impurities on the reactivity of carbon anodes in the aluminium industry. Special attention is given to sulphur since its effect on the carbon gasification is not well understood. Sulphur is always present in anodes, and it is expected that the sulphur content of available anode cokes will increase in the future. It has also been suggested that sulphur poisons catalyzing impurities in the anodes. Other impurities that were investigated are iron, nickel and vanadium, which are common impurities in anodes which have been reported to catalyze carbon gasification. 88 refs., 92 figs., 24 tabs.

  5. Anti-corrosive Conversion Coating on Aluminium Alloys Using High Temperature Steam

    DEFF Research Database (Denmark)

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

    extensively. Despite the intense research no equivalent substitute for (CrCCs) has been found. For these reasons, alternative conversion coatings are sought for substituting existing ones. Aluminium alloys AA 1090, Peraluman 706, and AA 6060 were subjected to high pressure steam treatment and various......-SEM, XRD, and FTIR. Potentiodynamic polarization measurements and acid salt spray testing were used to study the corrosion behavior of the produced coatings. In average, thickness of the oxide layer formed was increased to ~1-1.5 µm with steam treatment and various chemistries, and the coverage...

  6. Combustion characteristics of aluminium-iron oxidein SHS-gravitational process

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In order to get high quality of products, the combustion of aluminium-iron oxide thermite in SHS-gravitational process must be under control. The effects of thermite filling density, hole in thermite and inclined angle of pipe on combustion rate were studied. It shows that the combustion rate decreases with the decrease of filling density. The thermite combusts downwards the pipe much more quickly if there are holes in the thermite. And the combustion rate increases with the increase of the inclined angle of pipe. The experiment results show that the combustion of thermite is predominantly controlled by gas phasereaction, which is attributed to the high temperature of the thermitecombustion.

  7. Processless offset printing plates

    Directory of Open Access Journals (Sweden)

    Sanja Mahović Poljaček

    2015-06-01

    Full Text Available With the implementation of platesetters in the offset printing plate making process, imaging of the printing plate became more stable and ensured increase of the printing plate quality. But as the chemical processing of the printing plates still highly influences the plate making process and the graphic reproduction workflow, development of printing plates that do not require chemical processing for offset printing technique has been one of the top interests in graphic technology in the last few years. The main reason for that came from the user experience, where majority of the problems with plate making process could be connected with the chemical processing of the printing plate. Furthermore, increased environmental standards lead to reducing of the chemicals used in the industrial processes. Considering these facts, different types of offset printing plates have been introduced to the market today. This paper presents some of the processless printing plates.

  8. Aluminium oxide in the optical spectrum of VY Canis Majoris

    CERN Document Server

    Kaminski, T; Menten, K M

    2012-01-01

    We report the first identification of the optical bands of the B-X system of AlO in the red supergiant VY CMa. In addition to TiO, VO, ScO, and YO, which were recognized in the optical spectrum of the star long time ago, AlO is another refractory molecule which displays strong emission bands in this peculiar star. Simulating the bands of AlO, we derive a rotational temperature of the circumstellar gas of Trot=700K. By resolving individual rotational components of the bands, we derive the kinematical characteristics of the gas, finding that the emission is centered at the stellar radial velocity and its intrinsic width is 13.5 km/s (full width at half maximum). It is the narrowest emission among all (thermal) features observed in VY CMa so far. The temperature and line widths suggest that the emission arises in gas located within ~20 stellar radii, where the outflow is still being accelerated. This result contradicts equilibrium-chemistry models which predict substantial AlO abundances only to within a few ste...

  9. Aluminium: Aluminij: kovina izbire: the metal of choice:

    OpenAIRE

    Gándara, María Josefa Freiría

    2013-01-01

    This article summarizes the importance of aluminium as the metal of choice formany applications. Aluminium is a lightweight, durable metal. It is silvery in appearance when freshly cut, is a good conductor of heat and electricity, and is easily shaped by moulding and extruding. Aluminium has two main advantages when compared with other metals. Firstly, it has a low density, about one-third that of iron and copper. Secondly, although it reacts rapidly with the oxygen in air, it forms a thin, t...

  10. Optimization of Magnesium Metal into Commercially Pure Aluminium

    Directory of Open Access Journals (Sweden)

    Vandana J Rao

    2014-02-01

    Full Text Available The present investigation, involve development of Al-Mg systems by addition of magnesium into commercially pure aluminium. The amounts of magnesium added into commercially pure aluminium are of 1 and 2 wt%. The recoveries of magnesium are around 85-90%.Remaining Mg react with oxygen and float on the liquid aluminium. Presence of magnesium creates two phenomena. One is solid solution hardening and other is intermetallics formation. Both the phenomena checked by microstructural changes and by measuring the electrical conductivity values. By increasing the Mg, content mechanical properties (hardness and tensile strength increases and electrical conductivity decreases.

  11. Effect of filtration on reoxidation proceses in aluminium alloys

    Directory of Open Access Journals (Sweden)

    D. Bolibruchova

    2010-01-01

    Full Text Available This article is focused on reoxidation processes during filtration of aluminium alloys. Many of our experimental works pointed out, that using filtration media placed in gating system causes reoxidation of poured aluminium alloy. Main aim of our latest work was to validate our arguments, that filter in gating system can be considered as obstacle for continuous pouring, with help of computer simulations. This article is only a small part of our researches focused on reoxidation processes during filtration of aluminium alloys.

  12. 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...

  13. Radiation-induced creep of copper, aluminium and their alloys

    International Nuclear Information System (INIS)

    The results of creep studies on copper, aluminium and their alloys with and without neutron irradiation are presented. The experiments are carried out at the WWR-K reactor at the neutron fluence of 1.4.1016 n/m2.s (2.5.1016 n/m2.s, E>0.1 MeV). Polycrystalline copper (99.99 and 99.95%), aluminium (99.99%) and the alloys of copper with 4 at% of titanium, of aluminium with 4.2% of copper are studied within the temperature interval 0.31-0.51 Tm. (orig.)

  14. Study of fatigue behaviour of 7475 aluminium alloy

    Indian Academy of Sciences (India)

    B B Verma; J D Atkinson; M Kumar

    2001-04-01

    Fatigue properties of a thermomechanically treated 7475 aluminium alloy have been studied in the present investigation. The alloy exhibited superior fatigue life compared to conventional structural aluminium alloys and comparable stage II crack growth rate. It was also noticed that the fatigue crack initiated from a surface grain and the crack extension was dominated by ductile striations. Analysis also revealed that this alloy possessed fracture toughness and tensile properties superior to that noticed with other structural aluminium alloys. Therefore the use of this alloy can safely reduce the overall weight of the aircraft.

  15. Earnings Increased 500 Million Yuan Thanks to the Rise of Export Tax Rebate for Aluminium and Copper Products

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>In mid-November,the Ministry of Finance and the State Administration of Taxation issued a tax circular Notification on Raising Export Tax Rebate Rate of the Value-added Tax for Com- modities including Labor-intensive Products, raising the export tax rebate rate by 9% and 13% respectively for refined copper tubes with a outer diameter no more than 25mm and non- alloy aluminium products including rectangular plates,sheets and strips.This is the first time China has adjusted the export tax for nonfer- rous metal products.The adjustment will have a direct positive effect on improving the busi-

  16. Effect of Processing Parameters on the Protective Quality of Electroless Nickel-Phosphorus on Cast Aluminium Alloy

    OpenAIRE

    Olawale Olarewaju Ajibola; Daniel Toyin Oloruntoba; Adewuyi, Benjamin O.

    2015-01-01

    The effects of temperature, pH, and time variations on the protective amount and quality of electroless nickel (EN) deposition on cast aluminium alloy (CAA) substrates were studied. The temperature, pH, and plating time were varied while the surface condition of the substrate was kept constant in acid or alkaline bath. Within solution pH of 5.0–5.5 range, the best quality is obtained in acid solution pH of 5.2. At lower pH (5.0–5.1), good adhesion characterised the EN deposition. Within the r...

  17. The compatibility of chromium-aluminium steels with high pressure carbon dioxid at intermediate- temperatures; Compatibilite des aciers au chrome-aluminium avec le gaz carbonique sous pression aux temperatures moyennes

    Energy Technology Data Exchange (ETDEWEB)

    Leclercq, D.; Loriers, H.; David, R.; Darras, E. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    With a view to their use in the exchangers of nuclear reactors of the graphite-gas or heavy water-gas types, the behaviour of chromium-aluminium steels containing up to 7 per cent chromium and 1.5 per cent aluminium has been studied in the presence of high-pressure carbon dioxide at temperatures of between 400 and 700 deg. C. The two most interesting grades of steel (2 per cent Cr - 0.35 per cent Al - 0.35 per cent Mo and 7 per cent Cr - 1.5 per cent Al - 0.6 per cent Si) are still compatible with carbon dioxide up to 550 and 600 deg. C respectively. A hot dip aluminised coating considerably increases resistance to oxidation of the first grade and should make possible its use up to temperatures of at least 600 deg. C. (authors) [French] Dans l'optique de leur emploi dans les echangeurs de reacteurs nucleaires des filieres graphite-gaz ou eau lourde-gaz, le comportement en presence de gaz carbonique sous pression d'aciers au chrome-aluminium, contenant jusqu'a 7 pour cent de chrome et 1,5 pour cent d'aluminium a ete etudie entre 400 et 700 deg. C. Les deux nuances les plus interessantes (2 pour cent Cr - 0,35 pour cent Al - 0,35 pour cent Mo et 7 pour cent Cr - 1,5 pour cent Al - 0,6 pour cent Si) restent compatibles avec le gaz carbonique jusqu'a 550 et 600 deg. C respectivement. Un revetement d'aluminium, effectue par immersion dans un bain fondu, ameliore notablement la resistance a l'oxydation de la premiere et doit permettre son empioi jusqu'a 600 deg. C au moins. (auteurs)

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

    Science.gov (United States)

    Saiyed, Salim M; Yokel, Robert A

    2005-03-01

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

  19. Behaviour of plated structures subjected to blast loading

    Science.gov (United States)

    Aune, Vegard; Børvik, Tore; Langseth, Magnus

    2015-09-01

    An experimental investigation using a new shock tube facility to study blast-load effects on thin aluminium plates is presented. The shock tube is designed to expose materials and structures to extreme loading conditions, such as accidental explosions or terrorist attacks. The intensity of the loading in the present study was determined by the initial conditions of the compressed gas, i.e. volume and pressure, and the resulting loading on the target plate was compared to experimental data from explosive detonations found in the literature. The square plates were manufactured from a low-strength aluminium alloy and had an exposed area of 0.3 × 0.3 m2. Piezoelectric pressure sensors were used for pressure recordings and synchronized with two high-speed cameras operating at a frame rate of 21,000 fps in a stereoscopic setup to capture the dynamic response using a three-dimensional digital image correlation (3D-DIC) technique. The experiment showed that the shock tube is capable of recreating a loading similar to that of an unconfined far-field airblast, and worked as an easily controllable alternative to explosive detonations when studying the dynamic response of structures subjected to blast loading.

  20. Highly-dispersed Ta-oxide catalysts prepared by electrodeposition in a non-aqueous plating bath for polymer electrolyte fuel cell cathodes

    KAUST Repository

    Seo, Jeongsuk

    2012-01-01

    The Ta-oxide cathode catalysts were prepared by electrodeposition in a non-aqueous solution. These catalysts showed excellent catalytic activity and have an onset potential of 0.92 V RHE for the oxygen reduction reaction (ORR). The highly-dispersed Ta species at the nanometer scale on the carbon black was an important contributor to the high activity. © 2012 The Royal Society of Chemistry.

  1. A hybrid aluminium alloy and its zoo of interacting nano-precipitates

    Energy Technology Data Exchange (ETDEWEB)

    Wenner, Sigurd, E-mail: sigurd.wenner@ntnu.no [Department of Physics, NTNU, Høgskoleringen 5, NO-7491 Trondheim (Norway); Marioara, Calin Daniel; Andersen, Sigmund Jarle [Materials and Chemistry, SINTEF, Høgskoleringen 5, NO-7491 Trondheim (Norway); Ervik, Martin; Holmestad, Randi [Department of Physics, NTNU, Høgskoleringen 5, NO-7491 Trondheim (Norway)

    2015-08-15

    An alloy with aluminium as its base element is heat treated to form a multitude of precipitate phases known from different classes of industrial alloys: Al–Cu(–Mg), Al–Mg–Si–Cu, and Al–Zn–Mg. Nanometer-sized needle-shaped particles define the starting point of the phase nucleation, after which there is a split in the precipitation sequence into six phases of highly diverse compositions and morphologies. There are several unique effects of phases from different alloy systems being present in the same host lattice, of which we concentrate on two: the replacement of Ag by Zn on the Ω interface and the formation of combined plates of the θ′ and C phases. Using atomically resolved scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy, we investigate the formation mechanisms, crystal structures and compositions of the precipitates. - Graphical abstract: Display Omitted - Highlights: • An aluminium alloy composition in-between the 2/6/7xxx systems was investigated. • Six different phases from the three systems coexist in an over-aged state. • All phases with 〈001〉{sub Al} coherencies can nucleate on 6xxx needle precipitates. • Modified theta′ and omega interfaces are observed.

  2. Efficacy of chelation therapy to remove aluminium intoxication.

    Science.gov (United States)

    Fulgenzi, Alessandro; De Giuseppe, Rachele; Bamonti, Fabrizia; Vietti, Daniele; Ferrero, Maria Elena

    2015-11-01

    There is a distinct correlation between aluminium (Al) intoxication and neurodegenerative diseases (ND). We demonstrated how patients affected by ND showing Al intoxication benefit from short-term treatment with calcium disodium ethylene diamine tetraacetic acid (EDTA) (chelation therapy). Such therapy further improved through daily treatment with the antioxidant Cellfood. In the present study we examined the efficacy of long-term treatment, using both EDTA and Cellfood. Slow intravenous treatment with the chelating agent EDTA (2 g/10 mL diluted in 500 mL physiological saline administered in 2 h) (chelation test) removed Al, which was detected (using inductively coupled plasma mass spectrometry) in urine samples collected from patients over 12 h. Patients that revealed Al intoxication (expressed in μg per g creatinine) underwent EDTA chelation therapy once a week for ten weeks, then once every two weeks for a further six or twelve months. At the end of treatment (a total of 22 or 34 chelation therapies, respectively), associated with daily assumption of Cellfood, Al levels in the urine samples were analysed. In addition, the following blood parameters were determined: homocysteine, vitamin B12, and folate, as well as the oxidative status e.g. reactive oxygen species (ROS), total antioxidant capacity (TAC), oxidized LDL (oxLDL), and glutathione. Our results showed that Al intoxication reduced significantly following EDTA and Cellfood treatment, and clinical symptoms improved. After treatment, ROS, oxLDL, and homocysteine decreased significantly, whereas vitamin B12, folate and TAC improved significantly. In conclusion, our data show the efficacy of chelation therapy associated with Cellfood in subjects affected by Al intoxication who have developed ND.

  3. Investigation of background in large-area neutron detectors due to alpha emission from impurities in aluminium

    CERN Document Server

    Birch, J; Clergeau, J -F; van Esch, P; Ferraton, M; Guerard, B; Hall-Wilton, R; Hultman, L; Höglund, C; Jensen, J; Khaplanov, A; Piscitelli, F

    2015-01-01

    Thermal neutron detector based on films of $^{10}$B$_4$C have been developed as an alternative to $^3$He detectors. In particular, The Multi-Grid detector concept is considered for future large area detectors for ESS and ILL instruments. An excellent signal-to-background ratio is essential to attain expected scientific results. Aluminium is the most natural material for the mechanical structure of of the Multi-Grid detector and other similar concepts due to its mechanical and neutronic properties. Due to natural concentration of $\\alpha$ emitters, however, the background from $\\alpha$ particles misidentified as neutrons can be unacceptably high. We present our experience operating a detector prototype affected by this issue. Monte Carlo simulations have been used to confirm the background as $\\alpha$ particles. The issues have been addressed in the more recent implementations of the Multi-Grid detector by the use of purified aluminium as well as Ni-plating of standard aluminium. The result is the reduction in...

  4. Evaluation of corrosion resistance of aluminium coating with and without annealing against molten carbonate using electrochemical impedance spectroscopy

    Science.gov (United States)

    Ni, C. S.; Lu, L. Y.; Zeng, C. L.; Niu, Y.

    2014-09-01

    An arc ion plating (AIP) was used to fabricate a FeAl layer on 310S stainless steel to protect the sealing area being corroded by the molten carbonate in molten carbonate fuel cells (MCFCs). The degradation of aluminide coatings comes from both the corrosion of the coating in contact with the molten carbonate and the aluminium depletion due to the interdiffusion of aluminium and the substrate. The in-situ forming of aluminide in molten carbonate at 650 °C could be a possible way to reduce the inward diffusion of aluminium in the conventional pre-annealing at 850 °C. Electrochemical impedance spectroscopy (EIS) measurements were performed to model the corrosion of this pre-formed FeAl coating in comparison with the one formed in-situ in molten (0.62 Li+0.38 K)2CO3 at 650 °C. Although α-LiAlO2 is the corrosion product in both cases, the impedance spectra show distinct rate-limiting steps; the former is controlled by the charged particles passing through the scale, while the latter by their diffusion in the melt. The microstructure of the scale might be the reason for the difference in corrosion mechanism.

  5. Adsorption of aluminium by stream particulates.

    Science.gov (United States)

    Tipping, E; Ohnstad, M; Woof, C

    1989-01-01

    An experimental study was made of the adsorption of aluminium by fine particulates from Whitray Beck, a hill stream in NW England. Adsorption increased with Al(3) activity, pH and concentration of particles, and could be quantitatively described by the empirical equation: [Formula: see text] [particles] where square brackets indicate concentrations, curly brackets, activities, and alpha, beta and gamma are constants with values of 5.14x10(-10) (mol litre(-1))(2.015) (g particles litre(-1))(-1), 0.457, and 1.472, respectively. For the experimental data, the equation gave a correlation ratio of 0.99. The equation accounts reasonably well for the adsorption of Al by particulates from seven other streams. In applying the equation, it must be borne in mind that the desorption kinetics of Al depend on pH, and rapid reversibility (or=10%) of total monomeric Al. PMID:15092454

  6. Mechanical behaviour of aluminium-lithium alloys

    Indian Academy of Sciences (India)

    N Eswara Prasad; A A Gokhale; P Rama Rao

    2003-02-01

    Aluminium-lithium alloys hold promise of providing a breakthrough response to the crying need for lightweight alloys for use as structurals in aerospace applications. Considerable worldwide research has gone into developing a range of these alloys over the last three decades. As a result, substantial understanding has been developed of the microstructure-based micromechanisms of strengthening, of fatigue and fracture as well as of anisotropy in mechanical properties. However, these alloys have not yet greatly displaced the conventionally used denser Al alloys on account of their poorer ductility, fracture toughness and low cycle fatigue resistance. This review aims to summarise the work pertaining to study of structure and mechanical properties with a view to indicate the directions that have been and can be pursued to overcome property limitations.

  7. Study of interaction of uranium, plutonium and rare earth fluorides with some metal oxides in fluoric salt melts

    International Nuclear Information System (INIS)

    Interaction of plutonium, uranium, and rare-earth elements (REE) fluorides with aluminium and calcium oxides in melts of eutectic mixture LiF-NaF has been studied at 800 deg C by X-ray diffraction method. It has been shown that tetravalent uranium and plutonium are coprecipitated by oxides as a solid solution UO2-PuO2. Trivalent plutonium in fluorides melts in not precipitated in the presence of tetravalent uranium which can be used for their separation. REE are precipitated from a salt melt by calcium oxide and are not precipitated by aluminium oxide. Thus, aluminium oxide in a selective precipitator for uranium and plutonium in presence of REE. Addition of aluminium fluoride retains trivalent plutonium and REE in a salt melt in presence of Ca and Al oxides. The mechanism of interacting plutonium and REE trifluorides with metal oxides in fluoride melts has been considered

  8. 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.

  9. COMPARATION BETWEEN NONDESTRUCTIVE TESTING METHODS FOR THE ALUMINIUM BRAZED PIECES

    Directory of Open Access Journals (Sweden)

    Dan NIŢOI

    2014-05-01

    Full Text Available Presented paper refers to different control methods used in aluminium brazed joining because of possible defects. Low joining complexity permits exact damages position in relation with materials geometry.

  10. 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. PMID:26365318

  11. Deposition of aluminium nanoparticles using dense plasma focus device

    International Nuclear Information System (INIS)

    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.

  12. Friction Melt Bonding: An innovative process for aluminium-steel lap joints

    Directory of Open Access Journals (Sweden)

    Simar Aude

    2013-11-01

    Full Text Available A new process based on Friction Stir Welding has been developed to weld dissimilar metals, particularly steel and aluminum, in a lap-joint configuration. In this Friction Melt Bonding process, frictional heat generated by the rotating and translating tool brings about local and transient melting (Figure 1. Welding then occurs owing to controlled reactivity and solidification at the interface between the two plates. With an adequate choice of the welding parameters, low alloy steel and aluminium alloys have been successfully welded. Characterisation of the microstructure was systematically performed to highlight the influence of the process parameters, particularly the temperature cycle, on the steel-Al interface. The thickness of the intermetallic layer varies from a couple of micrometers to tens of micrometers depending on the advancing speed of the tool (Fig. 2. The lap shear properties of the joints were also investigated and analysed based on the morphology of the intermetallic layer.

  13. Investigations on temperature distribution in welding of Aluminium alloys to steel using FEM

    Directory of Open Access Journals (Sweden)

    K. S. Ashraff Ali

    2015-01-01

    Full Text Available This research study focuses on the objective to establish an analytical model for determining the thermal distribution during friction stir welding (FSW, based on different assumptions of the contact condition between the rotating tool surface and the weld piece. The material flow and heat generation are characterized by the contact conditions at the interface, and are described as sliding, sticking or partial sliding/sticking. The analytical expression for the heat generation is a modification of previous analytical models known from the literature and accounts for both conical surfaces and different contact conditions. Aluminium metal matrix composites and steel 304 (dissimilar material joining is being used for this study. Three dimensional Finite Element Models have been developed to visualize the temperature distribution across the butt ends of the plates. The results are validated with the experimental results reported in the literature. The result reveals that there exists a good coherence between experimental and simulated results.

  14. Plastic anisotropy of ultrafine grained aluminium alloys produced by accumulative roll bonding

    Energy Technology Data Exchange (ETDEWEB)

    Beausir, B., E-mail: benoit.beausir@univ-metz.fr [Institut fuer Strukturphysik, Technische Universitaet Dresden, D-01062 Dresden (Germany); Scharnweber, J. [Institut fuer Strukturphysik, Technische Universitaet Dresden, D-01062 Dresden (Germany); Jaschinski, J. [Institut fuer Leichtbau und Kunststofftechnik, Technische Universitaet Dresden, D-01062 Dresden (Germany); Brokmeier, H.-G. [GKSS Forschungszentrum, Max-Planck-Strasse, D-21494 Geesthacht (Germany); Oertel, C.-G.; Skrotzki, W. [Institut fuer Strukturphysik, Technische Universitaet Dresden, D-01062 Dresden (Germany)

    2010-05-25

    The plastic anisotropy of ultrafine grained aluminium alloys AA1050 and AA6016 produced by accumulative roll bonding (ARB) has been investigated by tensile deformation via the Lankford parameter. The average normal and planar anisotropies slightly increase (from 0.6 to 0.9) and decrease (from 0.6 to -0.7) as a function of ARB cycles, respectively. The global textures measured by neutron diffraction are used to simulate the Lankford and anisotropy parameters of the plates after 0, 2, 4, 6 and 8 ARB cycles with the help of the viscoplastic polycrystal self-consistent model. Simulation results are compared with those from experiment and discussed with regard to texture, strain rate sensitivity, grain shape and slip system activity.

  15. Aluminium dynamics and proton buttering in undistributed samples of acidified forest soils; Aluminium-Dynamik und Protonenpufferung in ungestoerten Proben versauerter Waldboeden

    Energy Technology Data Exchange (ETDEWEB)

    Fuchs, E.

    1992-12-31

    In this work non-displaced soil samples were used to test the reaction of acidified forest soils in the aluminium buffering range to different proton concentrations. The examined quantities were the proton buffering rate in the macropore spaces and the correlated rate of aluminium release. Furthermore, the types of aluminium bondage occuring in the soil solution and their influence on the aluminium dynamics within the profile were determined. The significance of species distribution for the interpretation of the toxic potential of aluminium is illuminated. The influence of soil structure on proton buffering, aluminium release and species distribution is described from a global viewpoint. (orig.) [Deutsch] In der vorliegenden Arbeit wird an natuerlich gelagerten Bodenproben die Reaktion versauerter Waldboeden im Aluminium-Pufferbereich auf unterschiedlich starke Protonenbelastungen untersucht. Dabei interessiert die Rate der Protonenpufferung im Makroporenraum einhergehend mit der Menge freigesetzten Aluminiums. Darueberhinaus wird untersucht, welche Aluminium-Bindungsformen in der Bodenloesung vorliegen und welchen Einfluss diese auf die Aluminium-Dynamik innerhalb des Profils haben. Die Bedeutung der Speziesverteilung fuer die Interpretation potentieller Aluminium-Toxizitaet wird beleuchtet. Uebergreifend wird der Einfluss der Bodenstruktur auf Protonenpufferung, Aluminium-Freisetzung sowie Speziesverteilung herausgestellt. (orig.)

  16. China’s Export of Fabricated Aluminium Keeps Rising

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    <正>Affected by the State macro economic adjustment policies, China’s export of primary aluminium has decreased obviously. However, China’s export of fabricated aluminum is increasing rapidly, which has led to the investment rush of the aluminium industry, leading to the serious concern by the government. Market rumors are spreading that the government will soon adjust the export tax rebate rates so as to curb such a trend.

  17. Modeling of aluminium deposition from chloroaluminate ionic liquids

    OpenAIRE

    Schaltin, Stijn; Ganapathi, Murugan; Binnemans, Koen; Fransaer, Jan

    2011-01-01

    A finite-element model of the electrodeposition of aluminium from chloroaluminate ionic liquids is introduced. The purpose of this model is to give an explanation for the reasonable current densities that can be achieved in chloroaluminate ionic liquids despite the fact that the electrochemically active Al2Cl7- complexes are transformed into inactive AlCl4- complexes during the electrodeposition of aluminium. The obtainable current density in the electrodeposition from chloroaluminate ionic l...

  18. Metal-Ceramic Interfaces in Laser Coated Aluminium Alloys

    NARCIS (Netherlands)

    Zhou, X.B.; Hosson, J.Th.M. De

    1994-01-01

    A novel process was developed to firmly coat an aluminium alloy, Al6061, with α-Al2O3 by means of laser processing. In this approach a mixture of SiO2 and Al powder was used to inject in the laser melted surface of aluminium. A reaction product α-Al2O3 layer of a thickness of 100 µm was created whic

  19. Crystallographic orientation-spray formed hypereutectic aluminium-silicon alloys

    OpenAIRE

    Hamilta de Oliveira Santos; Marilene Morelli Serna; Nelson Batista de Lima; Isolda Costa; Jesualdo Luiz Rossi

    2005-01-01

    Aluminium-silicon alloys have been wide accepted in the automotive, electric and aerospace industries. Preferred orientation is a very common condition for metals and alloys. Particularly, aluminium induces texture during the forming process. The preparation of an aggregate with completely random crystal orientation is a difficult task. The present work was undertaken to analyse the texture by X-ray diffraction techniques, of three spray formed hypereutectic Al-Si alloys. Samples were taken f...

  20. Local electrochemical behaviour of 7xxx aluminium alloys

    OpenAIRE

    F. Andreatta

    2004-01-01

    Aluminium alloys of the 7xxx series (Al-Zn-Mg-Cu) are susceptible to localized types of corrosion like pitting, intergranular corrosion and exfoliation corrosion. This represents a limitation for the application of these alloys in the aerospace components because localized corrosion might have a negative effect on safety and costs. This PhD thesis investigates the relation between electrochemical behaviour and microstructure of a number of 7xxx aluminium alloys: AA7075, AA7349 and an experime...

  1. Crushing modes of aluminium tubes under axial compression

    OpenAIRE

    Pled, Florent; Yan, Wenyi; Wen, Cui'e

    2014-01-01

    6 pages International audience A numerical study of the crushing of circular aluminium tubes with and without aluminium foam fillers has been carried out to investigate their buckling behaviours under axial compression. A crushing mode classification chart has been established for empty tubes. The influence of boundary conditions on crushing mode has also been investigated. The effect of foam filler on the crushing mode of tubes filled with foam was then examined. The predicted results ...

  2. Melting and solidification of bismuth inclusions in aluminium

    DEFF Research Database (Denmark)

    Thoft, N.B.; Bohr, J.; Buras, B.;

    1995-01-01

    Supercooling of crystalline bismuth inclusions in aluminium crystals has been observed and studied with different techniques: x-ray diffraction, in situ Rutherford backscattering/channelling spectrometry and transmission electron microscopy. The results of the measurements with different experime......Supercooling of crystalline bismuth inclusions in aluminium crystals has been observed and studied with different techniques: x-ray diffraction, in situ Rutherford backscattering/channelling spectrometry and transmission electron microscopy. The results of the measurements with different...

  3. Geometry Effects at Atomic-Size Aluminium Contacts

    OpenAIRE

    Schwingenschloegl, Udo; Schuster, Cosima

    2007-01-01

    We present electronic structure calculations for aluminium nanocontacts. Addressing the neck of the contact, we compare characteristic geometries to investigate the effects of the local aluminium coordination on the electronic states. We find that the Al 3pz states are very sensitive against modifications of the orbital overlap, which has serious consequences for the transport properties. Stretching of the contact shifts states towards the Fermi energy, leaving the system instable against fer...

  4. Adhesive Bonding of Aluminium Alloy A5754 by Epoxy Resins

    Directory of Open Access Journals (Sweden)

    Ivan Michalec

    2013-01-01

    Full Text Available Joining thin sheets of aluminium and its alloys is a promising area in the field of joining materials. Nowadays, joining methods that do not melt the material itself are increasingly being utilised. This paper deals with adhesive bonding of aluminium alloy A5754 by two-component epoxy resins. Theresults show that joints bonded by Hysol 9466 have appropriate mechanical properties, but that joints bonded by Hysol 9492 have better thermal stability.

  5. Prevention of Dealloying in Manganese Aluminium Bronze Propeller: Part II

    OpenAIRE

    Napachat Tareelap; Kaysinee Sriraksasin; Nakorn Srisukhumbowornchai; Swieng Thuanboon; Choochat Nitipanyawong

    2014-01-01

    Due to the failure of manganese aluminium bronze (MAB) propeller caused by dealloying corrosion as described in Part I [1], this work aims to study the prevention of dealloying corrosion using aluminium and zinc sacrificial anodes. The results indicated that both of the sacrificial anodes could prevent the propeller from dealloying. Moreover, the dealloying in seawater was less than that found in brackish water. It was possible that hydroxide ions, from cathodic reaction, reacted with calcium...

  6. 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...

  7. 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.

  8. 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.

  9. General Observations of the Time-Dependent Flow Field Around Flat Plates in Free Fall

    DEFF Research Database (Denmark)

    Hærvig, Jakob; Jensen, Anna Lyhne; Pedersen, Marie Cecilie;

    2015-01-01

    The free fall trajectories of flat plates are investigated in order to improve understanding of the forces acting on falling blunt objects. The long term goal is to develop a general applicable model to predict free fall trajectories. Numerically the free fall of a flat plate is investigated using...... with high accuracy, and thereby allowing the whole trajectory to be predicted with fair accuracy. With the numerical model able to predict the free fall and the complex plate fluid interactions, fluids forces can be extracted for model development in future studies....... a six degrees of freedom (6DOF) solver and a dynamic mesh. To validate the simulation, the trajectories of aluminium plates falling in water are recorded by digital camera recordings and compared to the simulation. The simulation is able to calculate the motion of the plate within each time step...

  10. Analysis of gamma ray spectrum of Al-Pu plate fuel elements

    International Nuclear Information System (INIS)

    Gamma ray spectrometry of aluminium (0.5mm thick) clad Al-Pu plate fuel elements containing ∼10 g plutonium per plate, was carried out using a high purity germanium detector (HPGe) and a 4K multichannel analyser. The detector to fuel plate distance was kept 750 mm to have a full view of the plate and to reduce dead time corrections. The data was analysed using peak fitting program SAMPO. Typical spectral shape obtained in this study is presented. Such spectral calibration avoids errors based on extrapolation from point source geometries and could be useful in evaluating (i) plutonium contents in similar plate fuels and in turn checking the final plutonium inventory and (ii)radiation fields at different working distances. (author). 3 refs., 1 fig., 1 tab

  11. Limb lengthening over plate

    Directory of Open Access Journals (Sweden)

    Ruta Kulkarni

    2012-01-01

    Conclusion: Lengthening over a plate allows early removal of external fixator and eliminates the risk of creating deep intramedullary infection as with lengthening over nail. Lengthening over plate is also applicable to children with open physis.

  12. Create Your Plate

    Medline Plus

    Full Text Available ... Planning Meals Diabetes Meal Plans Create Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook ... Create Your Plate Meal Planning for Vegetarian Diets Gluten Free Diets Holiday Meal Planning Cook with Heart- ...

  13. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook with Heart-Healthy Foods Holiday Meal ... Healthy Diet Create Your Plate Meal Planning for Vegetarian Diets Gluten Free Diets Holiday Meal Planning Cook ...

  14. Create Your Plate

    Medline Plus

    Full Text Available ... Yourself Fundraising & Local Events Matching Gift Fundraising Events Donate Stocks Give by ... Create Your Plate Create Your Plate is a simple and effective way to manage your blood glucose levels and lose weight. With this method, ...

  15. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate It's simple and effective for both managing diabetes and losing weight. Creating your plate lets ... Blog Online Community Site Menu Are You at Risk? Diagnosis Lower Your Risk Risk Test Alert Day ...

  16. Create Your Plate

    Medline Plus

    Full Text Available ... plates! Snap a photo and share it to social media with #CreateYourPlate . See the full gallery of ... you have an easy portion control solution that works. Last Reviewed: October 8, 2015 Last Edited: October ...

  17. Accelerated plate tectonics.

    Science.gov (United States)

    Anderson, D L

    1975-03-21

    The concept of a stressed elastic lithospheric plate riding on a viscous asthenosphere is used to calculate the recurrence interval of great earthquakes at convergent plate boundaries, the separation of decoupling and lithospheric earthquakes, and the migration pattern of large earthquakes along an arc. It is proposed that plate motions accelerate after great decoupling earthquakes and that most of the observed plate motions occur during short periods of time, separated by periods of relative quiescence.

  18. Vibration of plates

    CERN Document Server

    Chakraverty, Snehashish

    2008-01-01

    Plates are integral parts of most engineering structures and their vibration analysis is required for safe design. This work provides a comprehensive introduction to vibration theory and analysis of two-dimensional plates. It offers information on vibration problems along with a discussion of various plate geometries and boundary conditions.

  19. MyPlate

    Science.gov (United States)

    ... MyPlate What Is MyPlate? Fruits All About the Fruit Group Nutrients and Health Benefits Tips to Help You Eat Fruits Food ... lives. What Is MyPlate? Fruits All About the Fruit Group Nutrients and Health Benefits Tips to Help You Eat Fruits Food ...

  20. Influence of oxidation on electrical performance of silver-plated copper products and corresponding prevention and solution methods%氧化对铜基件镀银产品电气性能的影响及其预防和解决方法

    Institute of Scientific and Technical Information of China (English)

    孔凡蓬; 徐帆; 陈秉坚; 刘藩; 田勇

    2015-01-01

    The reasons for oxidation of silver coating on copper-based products were discussed from the two aspects of silver-plating process and environment. The electrical properties of oxidized silver-plated copper products were tested. Some anti-tarnish measures for silver coating, treatment methods after oxidation, and an alternative to silver coating were proposed.%从镀银工艺和环境两方面探讨了铜基镀银产品氧化的原因,分析了氧化后镀银产品的电气性能,提出了镀银层防变色的措施、氧化后处理方式和镀银层替代方案。

  1. China Rescinds the Export Tax on Aluminium Alloys Made by Scrap

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    <正>According to an official from the Tax Regulations Office under China’s State Council, from July 1st 2005, China will rescind the 5 per cent export tax on the aluminium alloys produced by using aluminium alloys scrap. An official from the State Council’s office said that through investigation they found that most aluminium alloys produced from aluminium scrap are not that energy consuming compared to primary aluminium. Starting from January 1st 2005, China decided to collect 5 per cent export tax on aluminium so as to control the industry development connected with high energy cost.

  2. Deformation measurements of blast loaded plates using digital image correlation and high-speed photography

    Directory of Open Access Journals (Sweden)

    Ndambi J.M.

    2010-06-01

    Full Text Available This paper presents a study on the behaviour of aluminium plates subject to close range blast loads. Measurement of the full out-of-plane displacement field is performed combining two high-speed cameras in a stereoscopic set up and the digital image correlation technique. The measured displacement fields are compared to the calculated data using two different FEM codes. A good agreement has been found between both experimental and numerical data.

  3. Plate tectonics, habitability and life

    Science.gov (United States)

    Spohn, Tilman; Breuer, Doris

    2016-04-01

    weathering of possible land surfaces and a biosphere could set up a CO2 sink that would further stabilize the temperature. As long as the planet keeps degassing CO2 at a sufficient rate, CO2 recycling through the mantle may not be required. However, this would require a sufficiently oxidized planet early on. If not sufficiently oxidized during accretion and core formation, oxidization of the planet would require cycling of matter between surface and interior reservoirs. Oxidization of an initially reduced Earth interior with the help of plate tectonics has been cited as a possible mechanism to allow the building up of oxygen in the terrestrial atmosphere around 2.3Ga b.p. (e.g., Catling and Claire, 2005), a pre-requisite for more evolved eukaryotic life. The oxidization would diminish a sink in the oxygen budget of the atmosphere by lowering the rate of outgassing of chemically reducing gases from the interior. Clearly, plate tectonics is a mechanism more potent of keeping a planet habitable and allow evolution of the biosphere than alternative concepts such as crust delamination. Catling, DC, Claire DW (2005), EPSL, 237, 1-20 Elkins-Tanton, L (2015) AGU Fall Meeting Abstract Tosi, N et al. (2016) EGU Abstract

  4. Use of trioctylphosphine oxide for transplutonium element extraction and purification

    International Nuclear Information System (INIS)

    Investigated was extraction of tri-valent curium, berkelium, californium, einsteinium as well as cerium and europium with trioctylphosphin oxide from lactic acid solutions, containing DTPA and aluminium nitrate depending on the aluminium nitrate and TOPO concentrations and nitric acid solutions of variable concentration as well. Under optimum conditions of extraction chromatography of berkelium studied was the distribution of cobalt, nickel, chromium, iron, aluminium, titanium, zirconium and niobium ions, and the coefficients of berkelium purification from cations investigated were determined. The effect of weight quantities of cation impurities on extraction chromatographic yield of berkelium has been investigated. Examples of practice application of the extraction chromatography with the use of TOPO are given

  5. Mechanical and frictional behaviour of nano-porous anodised aluminium

    Energy Technology Data Exchange (ETDEWEB)

    Tsyntsaru, N., E-mail: tintaru@phys.asm.md [Institute of Applied Physics of ASM, 5 Academy str., Chisinau, MD 2028 (Moldova, Republic of); Kavas, B., E-mail: bkavas@ford.com.tr [Istanbul Technical University, Department of Metallurgical and Materials Engineering, 34469 Maslak (Turkey); Ford Otomotiv San A.S., Istanbul (Turkey); Sort, J., E-mail: jordi.sort@uab.cat [Institució Catalana de Recerca i Estudis Avançats (ICREA) and Departament de Física, Universitat Autònoma de Barcelona, E-08193 Bellaterra (Spain); Urgen, M., E-mail: urgen@itu.edu.tr [Istanbul Technical University, Department of Metallurgical and Materials Engineering, 34469 Maslak (Turkey); Celis, J.-P., E-mail: jean-pierre.celis@mtm.kuleuven.be [KU Leuven, Dept. MTM, Kasteelpark Arenberg 44, B-3001 (Belgium)

    2014-12-15

    The porous structure of anodic aluminium oxide (AAO) can be used in versatile applications such as a lubricant reservoir in self-lubricating systems. Such systems are subjected to biaxial loading, which can induce crack formation and propagation, ultimately leading to catastrophic mechanical failure. In this study, the mechanical and tribological behaviour of AAO, prepared from two different types of electrolytes (sulphuric and oxalic acids), are studied in detail. The electrolytic conditions are adjusted to render highly tuneable average pore diameters (between 16 and 75 nm), with porosity levels ranging from 9% to 65%. Well-ordered porous AAO are produced by two-step anodization at rather low temperatures. Mechanical properties, mainly hardness and Young's modulus, are investigated using nanoindentation. Both the porosity degree and the composition of the electrolytic baths used to prepare the AAO have an influence on the mechanical properties. Ball-on-flat configuration was used to estimate the tribological behaviour under dry conditions. No major cracks were observed by scanning electron microscopy, neither after indentation or fretting tests. In the running-in period of tribology experiments the pores were filled with debris. This was followed by the formation of a highly adherent tribolayer – a third body consisting of fine worn particles originated from both the sample and the counterbody. Pore diameter and porosity percentage are found to strongly affect hardness and Young's modulus, but they do not have a major effect on the frictional behaviour. - Highlights: • Well-ordered porous AAO with pore diameters between 16 and 75 nm were produced. • Porosity and composition of electrolytic baths influence the mechanical properties. • Ball-on-flat configuration was used in tribological testing under dry conditions. • Adherent tribolayer consisting of fine worn particles prevents AAO from cracking. • Testing parameters are moreover essential

  6. 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.

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

    Science.gov (United States)

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

    2006-11-01

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

  8. Acute aluminium phosphide poisoning, what is new?

    Directory of Open Access Journals (Sweden)

    Yatendra Singh

    2014-01-01

    Full Text Available Aluminium phosphide (AlP is a cheap solid fumigant and a highly toxic pesticide that is commonly used for grain preservation. AlP has currently generated interest with increasing number of cases in the past four decades because of its increased use for agricultural and nonagricultural purposes, and also its easy availability in the markets has led to its increased misuse to commit suicide. Ingestion is usually suicidal in intent, uncommonly accidental and rarely homicidal. The poison affects all systems, shock, cardiac arrhythmias with varied ECG changes and gastrointestinal features being the most prominent. Diagnosis is made on the basis of clinical suspicion, a positive silver nitrate paper test to phosphine, and gastric aspirate and viscera biochemistry. Treatment includes early gastric lavage with potassium permanganate or a combination of coconut oil and sodium bicarbonate, administration of charcoal and palliative care. Specific therapy includes intravenous magnesium sulphate and oral coconut oil. Unfortunately, the lack of a specific antidote Results in very high mortality and the key to treatment lies in rapid decontamination and institution of resuscitative measures. This article aims to identify the salient features and mechanism of AlP poisoning along with its management strategies and prognostic variables.

  9. Low cost aluminium metal matrix composite

    Energy Technology Data Exchange (ETDEWEB)

    Withers, G.

    2007-03-15

    Low cost, light weight Ultalite{reg_sign} is an Aluminium Metal Matrix Composite (AL-MMC) which utilises wear resistant ceramic particles derived from flyash. Ultalite AL-MMC typically contains between 10 and 30 per cent ceramic particles, and is formulated for the manufacture of wear resistant automotive components. Due to its low density and ease of processing into net shape die casting, Ultalite AL-MMC provides weight savings of up to 60 per cent over components fabricated from cast iron, thereby providing improved fuel efficiency with reduced greenhouse emissions. The original flyash material was sourced from a black coal power station in Queensland, where it contained a wide range of particles sizes. To narrow the size range and to remove impurities, a proprietary pretreatment developed by Dr Thomas Robl and co-researchers at the University of Kentucky was employed. The University of Kentucky developed the technology for the classification and benefaction of flyash to produce high-grade Pozzolan, which is used in Portland Cement product. This technology is now being applied to the production of Ultalite AL-MMC. Testing performed by Dr Robl has shown that the proprietary technology can eliminate the hollow particles, extract detrimental carbon-based impurities and remove the extremely fine and coarse particles. All that remains are dense ceramic particles with an average particle size of approximately 30 {mu}m. 9 refs., 3 figs.

  10. Fuzzy Multicriteria Ranking of Aluminium Coating Methods

    Science.gov (United States)

    Batzias, A. F.

    2007-12-01

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

  11. Anomalous Diffusion of Mo Implanted into Aluminium

    Institute of Scientific and Technical Information of China (English)

    张通和; 吴瑜光; 邓志威; 钱卫东

    2001-01-01

    Mo ions are implanted into aluminium with a high ion flux and high dose at elevated temperatures of 300℃, 400℃ and 500℃ . X-ray diffraction spectra show that the Al12Mo phases are formed. Rutherford backscattering spectroscopy indicates that a profile of Mo appears in Al around the depth of 550nm and with an atomic concentration of ~7%, when Mo is implanted to the dose of 3 × 1017/cm2 with an ion flux of 45μA/cm2 (400℃).If the dose increases to 1 × 1018/cm2 at the same ion flux, the penetration of Mo ions in Al can reach a depth of 2μm, which is greater than the ion project range Rp (52.5nm). The results show that anomalous diffusion takes place. Owing to the intense atom collision cascades, the diffusion coefficient increases greatly with the increase of the ion flux and dose. The Mo diffusion coefficients in Al are calculated. The Mo retained dose in A1 increases obviously with the increase of the ion flux.

  12. 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.

  13. Microelectrolysis / plate setter / biological contact oxidation process for treatment of printed circuit board wastewater%EGSB-CASS-生物滤池工艺处理天然橡胶加工废水

    Institute of Scientific and Technical Information of China (English)

    姚颋; 江丹丹; 李杰

    2012-01-01

    根据某天然橡胶加工企业生产废水的水质特点,采用EGSB-CASS-生物滤池工艺处理天然橡胶加工废水。工程运行结果表明,该工艺对CODCr、氨氮、SS平均去除率分别达到97%,94%,90%,出水水质符合GB8978-1996《污水综合排放标准》一级标准。%The wastewater from a plant of printed circuit board were collected and treated separately according to the wastewater quality. The integrated wastewater was treated by microelectrolysis/plate setter/biological contact oxidation process. The operation results showed that the effluent quality reached the first class of "Integrated Wastewater Discharge Standard" (GB8978-1996). This research obtained a feasible approach for PCB wastewater treatment.

  14. Microelectrolysis/plate setter/biological contact oxidation process for treatment of printed circuit board wastewater%微电解/斜板沉淀/生物接触氧化处理印刷电路板废水

    Institute of Scientific and Technical Information of China (English)

    姚颋; 王宏; 李杰

    2011-01-01

    根据某印刷电路板企业生产废水的水质特点,对废水进行分类收集处理后,采用微电解/斜板沉淀/生物接触氧化工艺处理综合废水。工程运行结果表明,该工艺处理效果稳定,出水水质符合《污水综合排放标准》(GB8978-1996)的一级排放标准。%The wastewater from a plant of printed circuit board were collected and treated separately according tothe wastewater quality. The integrated wastewater was treated by microelectrolysis/plate setter/biological contact oxidation process. The operation results showed that the effluent quality reached the first class of "Integrated Wastewater Discharge Standard" (GB8978-1996).This research obtained a feasible approach for PCB wastewater treatment.

  15. 用氧化氨浸法从废旧镀铜铁针中提取铜的研究%Leaching of Copper From Waste Plated Copper Iron Needles by Oxidized Ammonia Leaching

    Institute of Scientific and Technical Information of China (English)

    温葆林; 谢添; 梁勇; 杨亮; 刘玉城; 郭斗斗; 郭年祥

    2014-01-01

    Recovery of copper from copper-plated iron needle come from electronics industry was conducted .Using mixed solution of ammonia and ammonium sulphate with oxidation in air as leaching agent ,under the conditions of reaction time of 120 min ,total ammonia concentration of 4 mol/L , n(ammonia)/n(ammonium) of 1/1 ,air flow of 1 L/min ,the ratio between liquid volume and solid mass of 5∶1 ,stirring speed of 400 r/min ,temperature of 40 ℃ ,the leaching rate of copper can reach as high as 99% ,the iron needles is not damaged .%研究了从电子工业中产生的镀铜铁针中回收铜。用氨水和硫酸铵混合溶液作浸出剂,控制反应时间为120 min、总氨浓度为4 mol/L、氨铵量比为1∶1、空气流量为1 L/min、液固体积质量比为5∶1、搅拌速度为400 r/min、温度为40℃,结果表明,铜浸出率达99%,且铁针未受损伤。

  16. Irradiation testing of miniature fuel plates for the RERTR program

    International Nuclear Information System (INIS)

    An irradiation test facility, which provides a test bed for irradiating a variety of miniature fuel plates (mini-plates) for the Reduced Enrichment Research and Test Reactors (RERTR) program, has been placed into operation. The objective of these tests is to screen various candidate fuel materials as to their suitability for replacing the highly-enriched uranium fuel materials currently used by the world's test and research reactors with a lower enrichment fuel material, without significantly degrading reactor operating characteristics and power levels. The use of low-uranium enrichment of about 20% 235U in place of highly enriched fuel for these reactors would reduce the potential for 235U diversion. Fuel materials currently being evaluated in this first phase of these screening tests include aluminium-base dispersion-type fuel plates with fuel cores of: (1) high uranium content U3O8-Al being developed by ORNL; (2) high uranium content UAl/sub x/-Al being developed by EG and G Idaho, Inc.; and (3) very high uranium content U3Si-Al being developed by ANL. The irradiation test facility, designated as HFED-1, is operating in core position E-7 in the Oak Ridge Research Reactor (ORR), a 30-MW water-moderated reactor. Ultimately, fuel plate types with suitable characteristics will be manufactured into full-sized plate-type fuel elements suitable for testing in the ORR. Specifications for these elements are described in Appendix A

  17. The General Situation of the Scale and Layout of Aluminium Industry in China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>Since 2002, aluminium industry has become a key industry under the macro control of the country, for which the reason is the aluminium industry in China has seen "repeated construc-tion", "blind investment", "excessive capacity",

  18. PREDICTION OF PLASTIC ANISOTROPY IN ALUMINIUM EXTRUDED TUBES BY FINITE ELEMENT POLYCRYSTAL MODEL

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Numerical simulation of extrusion process of aluminium tube is dealt with using the finite element polycrystal model. The non-uniformity in plastic anisotropies of aluminium extruded tubes through the wall thickness is investigated.

  19. Impact properties of aluminium - glass fiber reinforced plastics sandwich panels

    Directory of Open Access Journals (Sweden)

    Mathivanan Periasamy

    2012-06-01

    Full Text Available Aluminium - glass fiber reinforced plastics (GFRP sandwich panels are hybrid laminates consisting of GFRP bonded with thin aluminum sheets on either side. Such sandwich materials are increasingly used in airplane and automobile structures. Laminates with varying aluminium thickness fractions, fiber volume fractions and orientation in the layers of GFRP were fabricated by hand lay up method and evaluated for their impact performance by conducting drop weight tests under low velocity impacts. The impact energy required for initiating a crack in the outer aluminium layer as well as the energy required for perforation was recorded. The impact load-time history was also recorded to understand the failure behavior. The damage depth and the damage area were measured to evaluate the impact resistance. Optical photography and scanning electron micrographs were taken to visualize the crack and the damage zone. The bidirectional cross-ply hybrid laminate (CPHL has been found to exhibit better impact performance and damage resistance than the unidirectional hybrid laminate (UDHL. Increase in aluminium thickness fraction (Al tf and fiber volume fraction (Vf resulted in an increase in the impact energy required for cracking and perforation. On an overall basis, the sandwich panels exhibited better impact performance than the monolithic aluminium.

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

    OpenAIRE

    Polus Łukasz; Szumigała Maciej

    2015-01-01

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

  1. Influence of Alkali Treatment on the Surface Area of Aluminium Dross

    OpenAIRE

    Zauzi, N. S. Ahmad; M. Z. H. Zakaria; Baini, R.; Rahman, M. R.; N. Mohamed Sutan; Hamdan, S

    2016-01-01

    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, precipita...

  2. The determination of boron in high-purity aluminium metal by spark-source mass spectrometry

    International Nuclear Information System (INIS)

    A method is described for the determination of boron in high-purity aluminium metal. Both isotopic boron lines (10B+1 and 11B+1) are used for the analysis. As there are no low-abundance isotopic lines for aluminium, measurements were made direct without reference to aluminium as an internal standard. The boron concentration values of eight aluminium samples analysed by this method compared favourably with results obtained from other techniques

  3. Low Speed Laser Welding of Aluminium Alloys Using Single-Mode Fiber Lasers

    OpenAIRE

    Tu, Jay; Paleocrassas, Alexander

    2010-01-01

    In this chapter, topics related to extending fiber laser welding of aluminium in the low speed range were discussed. General topics, such as the properties of aluminium and welding defects, review of high speed laser welding of aluminium, and fiber laser characteristics and optical setups for safety, were first reviewed. Recent research results on the modelling and validation of laser welding of aluminium, experimental characterization of low speed welding processes, and the instability pheno...

  4. Waste minimization in chromium plating industry

    NARCIS (Netherlands)

    Frenzel, Ines

    2005-01-01

    Chromic acid is a strong oxidizing agent and plays an important role in metal finishing and plating industry. Chromate containing waste effluents are toxic and carcinogen and their treatment is chemical, energy and cost intensive. Therefore, waste prevention and waste treatment are in the focus of a

  5. Structure analysis of aluminium silicon manganese nitride precipitates formed in grain-oriented electrical steels

    Energy Technology Data Exchange (ETDEWEB)

    Bernier, Nicolas, E-mail: n.bernier@yahoo.fr [OCAS N.V., ArcelorMittal Global R and D Gent, Pres. J.F. Kennedylaan 3, 9060 Zelzate (Belgium); Xhoffer, Chris [OCAS N.V., ArcelorMittal Global R and D Gent, Pres. J.F. Kennedylaan 3, 9060 Zelzate (Belgium); Van De Putte, Tom, E-mail: tom.vandeputte@arcelormittal.com [OCAS N.V., ArcelorMittal Global R and D Gent, Pres. J.F. Kennedylaan 3, 9060 Zelzate (Belgium); Galceran, Montserrat [Université Libre de Bruxelles, 4MAT (Materials Engineering, Characterization, Synthesis and Recycling), Avenue F.D. Roosevelt 50, 1050 Brussels (Belgium); CIC Energigune, Albert Einstein 48, 01510 Miñano (Álava) (Spain); Godet, Stéphane [Université Libre de Bruxelles, 4MAT (Materials Engineering, Characterization, Synthesis and Recycling), Avenue F.D. Roosevelt 50, 1050 Brussels (Belgium)

    2013-12-15

    We report a detailed structural and chemical characterisation of aluminium silicon manganese nitrides that act as grain growth inhibitors in industrially processed grain-oriented (GO) electrical steels. The compounds are characterised using energy dispersive X-ray spectrometry (EDX) and energy filtered transmission electron microscopy (EFTEM), while their crystal structures are analysed using X-ray diffraction (XRD) and TEM in electron diffraction (ED), dark-field, high-resolution and automated crystallographic orientation mapping (ACOM) modes. The chemical bonding character is determined using electron energy loss spectroscopy (EELS). Despite the wide variation in composition, all the precipitates exhibit a hexagonal close-packed (h.c.p.) crystal structure and lattice parameters of aluminium nitride. The EDX measurement of ∼ 900 stoichiometrically different precipitates indicates intermediate structures between pure aluminium nitride and pure silicon manganese nitride, with a constant Si/Mn atomic ratio of ∼ 4. It is demonstrated that aluminium and silicon are interchangeably precipitated with the same local arrangement, while both Mn{sup 2+} and Mn{sup 3+} are incorporated in the h.c.p. silicon nitride interstitial sites. The oxidation of the silicon manganese nitrides most likely originates from the incorporation of oxygen during the decarburisation annealing process, thus creating extended planar defects such as stacking faults and inversion domain boundaries. The chemical composition of the inhibitors may be written as (AlN){sub x}(SiMn{sub 0.25}N{sub y}O{sub z}){sub 1−x} with x ranging from 0 to 1. - Highlights: • We study the structure of (Al,Si,Mn)N inhibitors in grain oriented electrical steels. • Inhibitors have the hexagonal close-packed symmetry with lattice parameters of AlN. • Inhibitors are intermediate structures between pure AlN and (Si,Mn)N with Si/Mn ∼ 4. • Al and Si share the same local arrangement; Mn is incorporated in both Mn

  6. PEMBINAAN PENGERAJIN BOKOR ALUMINIUM DI DESA MENYALI

    OpenAIRE

    I NYOMAN GDE ANTARA, dkk.

    2014-01-01

    Alluminium bowl craft industrial center is located in Menyali village Sawan district Buleleng regency of Bali province. In this business development, they faced some problems such as increasingly expensive alluminium plate raw materials, decreasing selling product prices due to competition among craftsmen, difficulty in extending the marketing, lack of capital, lack of knowledge in business management, and lack of technical capacity and production innovation. Currently the organization has be...

  7. Formation and Characterization of Ceramic Nanocomposite Crystalline Coatings on Aluminium by Anodization

    Institute of Scientific and Technical Information of China (English)

    M.Mubarak Ali; V.Raj

    2013-01-01

    Ceramic nanocomposite coatings have been synthesized on aluminium by using lithium sulphate electrolyte with zirconium silicate additive by anodization.The effects of current density (CD) on microhardness,structure,composition and surface topography of the oxide layer formed at various CDs (0.1-0.25 A/cm2) have been studied.Crystalline coatings formed at 0.25 A/cm2 have been (width 95 nm) observed with a relatively uniform distribution confirmed by scanning electron microscopy.Additionally,the average microhardness value of ceramic nanocomposite coatings fabricated from lithium sulphate-zirconium silicate bath is approximately 8.5 times higher than that of the as-received aluminium.The surface statistics of the coatings is discussed in detail to explain the roughness and related parameters for better understanding.These observations demonstrate the importance of surface statistics in controlling the morphology of the coatings and its properties.From the X-ray diffraction investigations,it can be concluded that the formed nanocomposite coatings are crystalline in nature and that the crystallinity of the coatings decreases with increasing applied current density.

  8. 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. PMID:21274747

  9. Automatic Licenses Plate Recognition

    OpenAIRE

    Ronak P Patel; Narendra M Patel; Keyur Brahmbhatt

    2013-01-01

    This paper describes the Smart Vehicle Screening System, which can be installed into a tollboothfor automated recognition of vehicle license plate information using a photograph of a vehicle. An automatedsystem could then be implemented to control the payment of fees, parking areas, highways, bridges ortunnels, etc. This paper contains new algorithm for recognition number plate using Morphological operation,Thresholding operation, Edge detection, Bounding box analysis for number plate extract...

  10. 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 p

  11. The Prospect of China’s Alumin-ium Extrusion Product Market

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>China’s aluminium extrusion industry can be dated back to the 1950s-70s,when the North- east 101 Plant was established in 1956,the Northwest Aluminium and Southwest Alumin- ium were completed and put into operation in 1968-1969.The three plants’ extrusion assem- bly lines were designed to produce aluminium

  12. The Net Exporting Trends Remains for China’s Aluminium Products

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>The oversupply of China’s raw aluminium has caused the continuing net exporting for China’s aluminium products.As the situation is wors- ened due to the growing raw aluminium pro- duction and curbed demand,it is estimated that the continuation of net exporting of China’s

  13. Bakable aluminium vacuum chamber and bellows with an aluminum flange and metal seal for ultrahigh vacuum

    International Nuclear Information System (INIS)

    A bakable (2000C) aluminium alloy vacuum chamber and bellows (6063-T6) with an aluminium alloy (2219-T87) flange and metal seal (Helicoflex-HN: aluminium O-ring) has been constructed. Such components may be used in the assemblies of the vacuum chambers in proton synchrotrons and electron storage rings

  14. Energy efficiency improvement and GHG abatement in the global production of primary aluminium

    NARCIS (Netherlands)

    Kermeli, Katerina; Ter Weer, Peter Hans; Crijns - Graus, Wina; Worrell, Ernst

    2015-01-01

    Primary aluminium production is a highly energy-intensive and greenhouse gas (GHG)-emitting process responsible for about 1 % of global GHG emissions. In 2009, the two most energy-intensive processes in primary aluminium production, alumina refining and aluminium smelting consumed 3.1 EJ, of which 2

  15. Residual stress in 7449 aluminium alloy forgings

    International Nuclear Information System (INIS)

    The through thickness residual stress distributions within three 120 mm thick rectilinear forgings, made from the high strength aluminium alloy 7449 have been measured using both neutron diffraction and deep hole drilling. Neutron diffraction measurements were made on two instruments, one using a pulsed spallation neutron source, the other a steady state reactor source. Heat treatment of the forgings included a rapid quench into cold water and it was the residual stresses arising from this step that were initially measured. Neutron diffraction measurements indicated large magnitude (>250 MPa) tensile residual stresses in the centre of an as quenched forging, balanced by surface regions stressed in compression (<-200 MPa). Sufficient measurements were made to permit the description of the residual stress distribution using area maps. Two forgings were stress relieved by cold compression immediately after quenching. The degree of plastic strain was either 2.5% or 4%, and was applied by a single application of force in the short transverse direction. Cold compressed forgings were found to have far lower residual stress when compared to the as quenched condition. The amount of cold compression was found to cause an insignificant difference in the final residual stress distribution. The neutron diffraction results are compared to measurements made by deep hole drilling and a new incremental variation of the technique. The deep hole was drilled through the centre of the forgings in the short transverse direction. Multiple neutron diffraction measurements were also made on the extracted cores from the deep hole measurements to assess the variation of the unstrained lattice parameter through the thickness of the forgings.

  16. Fractal Plate Tectonics

    OpenAIRE

    Sornette, D.; V. F. Pisarenko

    2002-01-01

    We analyze in details the statistical significance of the claim by Bird [2002] of a power law distribution of plate areas covering the Earth and confirm that the power law with exponent 0.25 +- 0.05 is the most robust and parsimonious model for all plates, including the very largest plates, when taking into account the constraint that the plates areas must sum up to 4 pi steradians. We propose a general class of fragmentation models that rationalize this observation and discuss the implicatio...

  17. Generalized Fibonacci zone plates

    CERN Document Server

    Ke, Jie; Zhu, Jianqiang

    2015-01-01

    We propose a family of zone plates which are produced by the generalized Fibonacci sequences and their axial focusing properties are analyzed in detail. Compared with traditional Fresnel zone plates, the generalized Fibonacci zone plates present two axial foci with equal intensity. Besides, we propose an approach to adjust the axial locations of the two foci by means of different optical path difference, and further give the deterministic ratio of the two focal distances which attributes to their own generalized Fibonacci sequences. The generalized Fibonacci zone plates may allow for new applications in micro and nanophotonics.

  18. 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.

  19. [Photophysical properties and photodynamic activity of nanostructured aluminium phthalocyanines].

    Science.gov (United States)

    Udartseva, O O; Lobanov, A V; Andeeva, E R; Dmitrieva, G S; Mel'nikov, M Ia; Buravkova, L B

    2014-01-01

    We developed water-soluble supramolecular complexes of aluminium phthalocyanine based on mesoporous silica nanoparticles and polyvinylpirrolidone containing rare photoactive nanoaggregates. Radiative lifetimes, extinction coefficients and energy of electronic transitions of isolated and associated metal phthalocyanine complexes were calculated. Nontoxic concentrations of synthesized nanocomposite photosensibilizers were in vitro determined. In present study we compared photodynamic treatment efficacy using different modifications of aluminium phthalocyanine (Photosens®, AlPc-nSiO2 and AlPc-PVP). Mesenchymal stromal cells were used as a model for photodynamic treatment. Intracellular accumulation of aluminium phthalocyanine based on mesoporous silica nanoparticles AlPc-nSiO2 was the most efficient. Illumination of phthalocyanine-loaded cells led to reactive oxygen species generation and subsequent apoptotic cell death. Silica nanoparticles provided a significant decrease of effective phthalocyanine concentration and enhanced cytotoxicity of photodynamic treatment.

  20. Reflection of infrared radiation from thin aluminium layers

    CERN Document Server

    Calatroni, Sergio

    2001-01-01

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