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Sample records for superdense aluminium synthesized

  1. Titanat aluminium synthesized in a solar furnace

    Energy Technology Data Exchange (ETDEWEB)

    Suleimanov, S.; Gulamova, D. [Uzbek Academy of Sciences, Tashkent (Uzbekistan). Materials Science Inst.; Boehmer, M.; Fend, T.; Rietbrock, P. [DLR, Koeln (Germany). MD-ET

    1997-12-31

    Solar furnace technology is an ecologically clean and economically attractive way, most suitable for research and development of new advanced materials. Such features of the solar furnace as sterile conditions of heating, high speed temperature delivering, materials processing in the whole range of the solar spectrum, quenching of the melt with rates of {proportional_to}10{sup 6} K/s, possibility of melting in the cold crucible etc. allow to synthesize complex oxide compositions, such as Al{sub 2}TiO{sub 5}. The study of Al{sub 2}TiO{sub 5} synthesized in the solar furnace has shown that the material is pure {beta}-Al{sub 2}TiO{sub 5} and possesses orthorhombic crystal structure. Microstructure of the material obtained from the melt has a prolonged prismatic shape. When the material is obtained by quenching the microstructure displays fine-grain structure with crystallites of 3-5 micron in size. Raman spectroscopy investigations have been performed on {beta}-Al{sub 2}TiO{sub 5} synthesized on the solar furnace. It has been observed a distinct band at 900 1/cm which is not presented in other six coordinated titanates. Most probably this band is connected with valent vibrations of the Al-O coupling in distorted octahedrons [AlO{sub 6}]. (orig.)

  2. A new synthesis process for aluminium nitride. Nouveau procede de synthese du nitrure d'aluminium

    Energy Technology Data Exchange (ETDEWEB)

    Haussonne, J.M. (CNET, Centre Lannion B, 22 (France)); Lostec, J. (CNET, Centre Lannion B, 22 (France)); Bertot, J.P. (CNET, Centre Lannion B, 22 (France)); Lostec, L. (CNET, Centre Lannion B, 22 (France)); Sadou, S. (CNET, Centre Lannion B, 22 (France))

    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/Al[sub 2]O[sub 3] composites, we have mixed aluminium powders with lithium salts, and easily synthesized pure aluminium nitride by heating the mixed powders in nitrigen at temperatures ranging from 800 to 1200 C. Starting from aluminium powders with a specific area ranging from 0.3 to 4 m[sup 2]/g, we have been able to produce aluminium nitride with specific are ranging from 1 to 20 m[sup 2]/g. Mixed with Y[sub 2]O[sub 3]-CaO and sintered at 1720 C in N[sub 2], we obtained AlN ceramics owning 92% density and 160 W/m.K thermal conductivity. (orig.).

  3. Superhydrophobic coatings for aluminium surfaces synthesized by chemical etching process

    Directory of Open Access Journals (Sweden)

    Priya Varshney

    2016-10-01

    Full Text Available In this paper, the superhydrophobic coatings on aluminium surfaces were prepared by two-step (chemical etching followed by coating and one-step (chemical etching and coating in a single step processes using potassium hydroxide and lauric acid. Besides, surface immersion time in solutions was varied in both processes. Wettability and surface morphologies of treated aluminium surfaces were characterized using contact angle measurement technique and scanning electron microscopy, respectively. Microstructures are formed on the treated aluminium surfaces which lead to increase in contact angle of the surface (>150°. Also on increasing immersion time, contact angle further increases due to increase in size and depth of microstructures. Additionally, these superhydrophobic coatings show excellent self-cleaning and corrosion-resistant behavior. Water jet impact, floatation on water surface, and low temperature condensation tests assert the excellent water-repellent nature of coatings. Further, coatings are to be found mechanically, thermally, and ultraviolet stable. Along with, these coatings are found to be excellent regeneration ability as verified experimentally. Although aforesaid both processes generate durable and regenerable superhydrophobic aluminium surfaces with excellent self-cleaning, corrosion-resistant, and water-repellent characteristics, but one-step process is proved more efficient and less time consuming than two-step process and promises to produce superhydrophobic coatings for industrial applications.

  4. Optimal superdense coding over memory channels

    Energy Technology Data Exchange (ETDEWEB)

    Shadman, Z.; Kampermann, H.; Bruss, D.; Macchiavello, C. [Institute fuer Theoretische Physik III, Heinrich-Heine-Universitaet Duesseldorf, DE-40225 Duesseldorf (Germany); Dipartimento di Fisica ' ' A. Volta' ' and INFM-Unita di Pavia, Via Bassi 6, IT-27100 Pavia (Italy)

    2011-10-15

    We study the superdense coding capacity in the presence of quantum channels with correlated noise. We investigate both the cases of unitary and nonunitary encoding. Pauli channels for arbitrary dimensions are treated explicitly. The superdense coding capacity for some special channels and resource states is derived for unitary encoding. We also provide an example of a memory channel where nonunitary encoding leads to an improvement in the superdense coding capacity.

  5. Superdense Coding via Hot Trapped Ions

    Institute of Scientific and Technical Information of China (English)

    QIN Tao; FENG Mang; GAO Ke-Lin

    2004-01-01

    Superdense coding plays an important role in quantum information and can be performed with trapped ions. By confining the ions in a linear trap or a trap-cavity setup, we propose schemes to implement a reliable superdense coding by means of bichromatic radiation method. Experimental feasibility and reliability for achieving our schemes is discussed in detail.

  6. Superdense Coding Interleaved with Forward Error Correction

    Directory of Open Access Journals (Sweden)

    Sadlier Ronald J.

    2016-01-01

    Full Text Available Superdense coding promises increased classical capacity and communication security but this advantage may be undermined by noise in the quantum channel. We present a numerical study of how forward error correction (FEC applied to the encoded classical message can be used to mitigate against quantum channel noise. By studying the bit error rate under different FEC codes, we identify the unique role that burst errors play in superdense coding, and we show how these can be mitigated against by interleaving the FEC codewords prior to transmission. We conclude that classical FEC with interleaving is a useful method to improve the performance in near-term demonstrations of superdense coding.

  7. 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.

  8. Implications of tachyon-like matter for superdense stars.

    Science.gov (United States)

    Bhatia, M. S.; Pande, L. K.

    1972-01-01

    Derivation of a new equation of state of superdense matter by treating superdense matter as a perfect, degenerate tachyon gas. Model calculations for superdense stars based on this equation of state are presented. By appropriately choosing a certain parameter, dynamical stability can be achieved for arbitrarily large central densities. Also, a somewhat larger than usual value for the maximum mass is obtained.

  9. Deterministic mediated superdense coding with linear optics

    Energy Technology Data Exchange (ETDEWEB)

    Pavičić, Mladen, E-mail: mpavicic@physik.hu-berlin.de [Department of Physics—Nanooptics, Faculty of Mathematics and Natural Sciences, Humboldt University of Berlin (Germany); Center of Excellence for Advanced Materials and Sensing Devices (CEMS), Photonics and Quantum Optics Unit, Ruđer Bošković Institute, Zagreb (Croatia)

    2016-02-22

    We present a scheme of deterministic mediated superdense coding of entangled photon states employing only linear-optics elements. Ideally, we are able to deterministically transfer four messages by manipulating just one of the photons. Two degrees of freedom, polarization and spatial, are used. A new kind of source of heralded down-converted photon pairs conditioned on detection of another pair with an efficiency of 92% is proposed. Realistic probabilistic experimental verification of the scheme with such a source of preselected pairs is feasible with today's technology. We obtain the channel capacity of 1.78 bits for a full-fledged implementation. - Highlights: • Deterministic linear optics mediated superdense coding is proposed. • Two degrees of freedom, polarization and spatial, are used. • Heralded source of conditioned entangled photon pairs, 92% efficient, is proposed.

  10. On superdense coding with noisy channels

    Energy Technology Data Exchange (ETDEWEB)

    Shadman, Zahra; Kampermann, Hermann; Bruss, Dagmar [Heinrich-Heine-Universitaet, Institut fuer Theoretische Physik III, Duesseldorf (Germany)

    2009-07-01

    We study the capacity of a superdense coding protocol in the case of a noisy channel. We consider the case where the channel acts on Alice's side, and the one where it acts both on Alice's and Bob's side. In the latter case, the noise can be correlated or uncorrelated. We study various noise models and various bipartite input states, and derive the optimal capacity.

  11. Classical information capacity of superdense coding

    CERN Document Server

    Bowen, G H

    2001-01-01

    Classical communication through quantum channels may be enhanced by sharing entanglement. Superdense coding allows the encoding, and transmission, of up to two classical bits of information in a single qubit. In this paper, the maximum classical channel capacity for states that are not maximally entangled is derived. Particular schemes are then shown to attain this capacity, firstly for pairs of qubits, and secondly for pairs of qutrits.

  12. Quantum superdense coding based on hyperentanglement

    Institute of Scientific and Technical Information of China (English)

    Zhao Rui-Tong; Guo Qi; Chen Li; Wang Hong-Fu; Zhang Shou

    2012-01-01

    We present a scheme for quantum superdense coding with hyperentanglement,in which the sender can transfer four bits of classical information by sending only one photon.The important device in the scheme is the hyperentangled Bell-state analyzer in both polarization and frequency degrees of freedom,which is also constructed in the paper by using a quantum nondemolition detector assisted by cross-Kerr nonlinearity.Our scheme can transfer more information with less resources than the existing schemes and is nearly deterministic and nondestructive.

  13. Evidence of Formation of Superdense Nonmagnetic Cobalt

    Science.gov (United States)

    Banu, Nasrin; Singh, Surendra; Satpati, B.; Roy, A.; Basu, S.; Chakraborty, P.; Movva, Hema C. P.; Lauter, V.; Dev, B. N.

    2017-02-01

    Because of the presence of 3d transition metals in the Earth’s core, magnetism of these materials in their dense phases has been a topic of great interest. Theory predicts a dense face-centred-cubic phase of cobalt, which would be nonmagnetic. However, this dense nonmagnetic cobalt has not yet been observed. Recent investigations in thin film polycrystalline materials have shown the formation of compressive stress, which can increase the density of materials. We have discovered the existence of ultrathin superdense nonmagnetic cobalt layers in a polycrystalline cobalt thin film. The densities of these layers are about 1.2–1.4 times the normal density of Co. This has been revealed by X-ray reflectometry experiments, and corroborated by polarized neutron reflectometry (PNR) experiments. Transmission electron microscopy provides further evidence. The magnetic depth profile, obtained by PNR, shows that the superdense Co layers near the top of the film and at the film-substrate interface are nonmagnetic. The major part of the Co film has the usual density and magnetic moment. These results indicate the possibility of existence of nonmagnetic Co in the earth’s core under high pressure.

  14. Experimental proposal of probabilistic superdense coding with linear optical elements

    Energy Technology Data Exchange (ETDEWEB)

    Lin Qing; Li Jian; Guo Guangcan [Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026 (China)

    2006-09-14

    In this paper, we propose an experimental scheme of probabilistic superdense coding assisted with linear optical manipulations, photon entanglement produced from parametric down-conversion and postselection from coincidence measurements. The proposal is feasible by current experimental technology.

  15. NMR experimental implementation of three-parties quantum superdense coding

    Institute of Scientific and Technical Information of China (English)

    WEI Daxiu; YANG Xiaodong; LUO Jun; SUN Xianping; ZENG Xizhi; LIU Maili

    2004-01-01

    In this study, we report an experiment realization of quantum superdense coding (QSDC) between three parties using nuclear magnetic resonance (NMR). The experimental results have shown that in terms of the QSDC schemes between multiparties proposed by Liu et al. and Crudka et al., three-qubit QSDC can transmit three bits of classical information by sending two qubits only. Our results experimentally show that quantum superdense coding, as one of the quantum information processing protocols, is superior to classical ones.

  16. Tikekar superdense stars in electric fields

    Science.gov (United States)

    Komathiraj, K.; Maharaj, S. D.

    2007-04-01

    We present exact solutions to the Einstein-Maxwell system of equations with a specified form of the electric field intensity by assuming that the hypersurface {t=constant} are spheroidal. The solution of the Einstein-Maxwell system is reduced to a recurrence relation with variable rational coefficients which can be solved in general using mathematical induction. New classes of solutions of linearly independent functions are obtained by restricting the spheroidal parameter K and the electric field intensity parameter α. Consequently, it is possible to find exact solutions in terms of elementary functions, namely, polynomials and algebraic functions. Our result contains models found previously including the superdense Tikekar neutron star model [J. Math. Phys. 31, 2454 (1990)] when K=-7 and α=0. Our class of charged spheroidal models generalize the uncharged isotropic Maharaj and Leach solutions [J. Math. Phys. 37, 430 (1996)]. In particular, we find an explicit relationship directly relating the spheroidal parameter K to the electromagnetic field.

  17. Entanglement witness derived from NMR superdense coding

    Energy Technology Data Exchange (ETDEWEB)

    Rahimi, Robabeh [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan); Takeda, Kazuyuki [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan); Ozawa, Masanao [Graduate School of Information Sciences, Tohoku University, Aoba-ku, Sendai 980-8579 (Japan); Kitagawa, Masahiro [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan)

    2006-03-03

    It is shown that superdense coding (SDC) experiments by means of nuclear magnetic resonance (NMR) can show non-classical efficiency gain over classical communication only for nuclear spin polarization beyond a certain threshold, and this threshold coincides with that for non-separability of the density matrix. It is also claimed that transfer of two-bit information mediated by a single qubit in the previous NMR SDC experiments with low nuclear spin polarization is not ascribed to the non-classical effect induced by entanglement, but merely to a statistical effect in an ensemble system having a large number of molecules. Towards experimental detection of entanglement, a new class of entanglement witnesses is proposed, which is based on the measurement of nuclear spin magnetizations in the Bell basis and is suitable for actual NMR experiments.

  18. Superdense massive galaxies in the Nearby Universe

    CERN Document Server

    Trujillo, Ignacio; de Lorenzo-Caceres, Adriana; Vazdekis, Alexandre; de la Rosa, Ignacio G; Cava, Antonio

    2009-01-01

    Superdense massive galaxies (r_e~1 kpc; M~10^{11} Msun) were common in the early universe (z>1.5). Within some hierarchical merging scenarios, a non-negligible fraction (1-10%) of these galaxies is expected to survive since that epoch retaining their compactness and presenting old stellar populations in the present universe. Using the NYU Value-Added Galaxy Catalog from the SDSS Data Release 6 we find only a tiny fraction of galaxies (~0.03%) with r_e8x10^{10} Msun in the local Universe (z<0.2). Surprinsingly, they are relatively young (~2 Gyr) and metal-rich ([Z/H]~0.2). The consequences of these findings within the current two competing size evolution scenarios for the most massive galaxies ("dry" mergers vs "puffing up" due to quasar activity) are discussed.

  19. Quantum control using genetic algorithms in quantum communication: superdense coding

    Science.gov (United States)

    Domínguez-Serna, Francisco; Rojas, Fernando

    2015-06-01

    We present a physical example model of how Quantum Control with genetic algorithms is applied to implement the quantum superdense code protocol. We studied a model consisting of two quantum dots with an electron with spin, including spin-orbit interaction. The electron and the spin get hybridized with the site acquiring two degrees of freedom, spin and charge. The system has tunneling and site energies as time dependent control parameters that are optimized by means of genetic algorithms to prepare a hybrid Bell-like state used as a transmission channel. This state is transformed to obtain any state of the four Bell basis as required by superdense protocol to transmit two bits of classical information. The control process protocol is equivalent to implement one of the quantum gates in the charge subsystem. Fidelities larger than 99.5% are achieved for the hybrid entangled state preparation and the superdense operations.

  20. Growth Mechanism and Optimized Parameters to Synthesize Nation-115 Nanowire Arrays with Anodic Aluminium Oxide Membranes as Templates

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lu; PAN Cao-Feng; ZHU Jing

    2008-01-01

    @@ Nafion-115 nanowire arrays are synthesized with an extrusion method using AAO membranes as templates. It is indicated that the vacuum treating of AAO templates before surface decoration plays an important role in obtaining high filling rate of the Nafion-115 nanowires in the AAO templates, while the concentration of Nafion-115 DMSO solutions does not affect the filling rate greatly. The optimized parameters to synthesize the Nafion-115 nanowire arrays are studied. The filling rate of the Nafion-115 nanowires in the AAO templates synthesized with the optimized parameters is about 95%. The growth mechanism of Nafion-115 nanowires is discussed to qualitatively explain the experimental results.

  1. Quantum Secure Direct Intercommunication with Superdense Coding and Entanglement Swapping

    Institute of Scientific and Technical Information of China (English)

    HUANG Da-Zu; GUO Ying; ZENG Gui-Hua

    2008-01-01

    A quantum secure direct intercommunication scheme is proposed to exchange directly the communicators' secret messages by making use of swapping entanglement of Bell states. It has great capacity to distribute the secret messages since these messages have been imposed on high-dimensional Bell states via the local unitary operations with superdense coding. The security is ensured by the secure transmission of the travel sequences and the application of entanglement swapping.

  2. Quantum superdense coding via cavity-assisted interactions

    Institute of Scientific and Technical Information of China (English)

    Pan Guo-Zhu; Yang Ming; Cao Zhuo-Liang

    2009-01-01

    Quantum superdense coding (QSC) is an example of how entanglement can be used to minimize the number of carriers of classical information. This paper proposes two schemes for implementing QSC by means of cavity assisted interactions with single-photon pulses. The schemes are insensitive to the cavity decay and the thermal field, thus it might be realizable based on the current cavity QED techniques.

  3. Aluminium bridges, aluminium bridge decks

    NARCIS (Netherlands)

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

    2003-01-01

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

  4. Aluminium bridges, aluminium bridge decks

    NARCIS (Netherlands)

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

    2003-01-01

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

  5. Constraints on superdense preon stars and their formation scenarios

    CERN Document Server

    Horváth, J E

    2007-01-01

    We address in this work the general features of a possible compact stars composed by elementary fermions beyond the quark level. The {\\it locus} of these hypothetic objects in the mass-radius plane is constructed for the maximum mass (minimum radius) of the sequence of models in terms of a compositeness scale only, and in fact this approach applies for any composite model postulating fermions at or beyond the preon level. We point out a constraint on the preon mass arising from the applicability of the General Relativity structure equations, leading to the questioning of the hypothesis of light preons if the preon scale is high, provided classical compact objects are enforced. Some remarks on the existence of superdense stars of astrophysical and primordial origin are made and discussed.

  6. Constraints on superdense preon stars andtheir formation scenarios

    Science.gov (United States)

    Horvath, J. E.

    2007-02-01

    We address in this work the general features of a possible compact stars composed by elementary fermions beyond the quark level. The locus of these hypothetic objects in the mass-radius plane is constructed for the maximum mass (minimum radius) of the sequence of models in terms of a compositeness scale only, and in fact this approach applies for any composite model postulating fermions at or beyond the preon level. We point out a constraint on the preon mass arising from the applicability of the General Relativity structure equations, leading to the questioning of the hypothesis of light preons if the preon scale is high, provided classical compact objects are enforced. Some remarks on the existence of superdense stars of astrophysical and primordial origin are made and discussed.

  7. The states of W-class as shared resources for perfect teleportation and superdense coding

    Energy Technology Data Exchange (ETDEWEB)

    Li, Lvzhou; Qiu, Daowen [Department of Computer Science, Zhongshan University, Guangzhou 510275 (China)

    2007-08-31

    As we know, the states of triqubit systems have two important classes: GHZ-class and W-class. In this paper, the states of W-class are considered for teleportation and superdense coding, and they are generalized to multi-particle systems. First we describe two transformations on the shared resources for teleportation and superdense coding. With these transformations, we obtain a sufficient and necessary condition for a state of W-class being suitable for perfect teleportation and superdense coding. For the state vertical bar W>{sub 123} = 1/2 (vertical bar 100>{sub 123} + vertical bar 010>{sub 123} + {radical}2 vertical bar 001>{sub 123}) which was thought to be not suitable for sending three classical bits by sending two qubits by Agrawal and Pati (2006 Phys. Rev. A 74 062320), we show that it may be used to fulfil that task, if entangled unitary operations on two qubits are allowed. We generalize the states of W-class to multi-qubit systems and multi-particle systems with higher dimension. We propose two protocols for teleportation and superdense coding by using W-states of multi-qubit systems that generalize the protocols by using |W){sub 123} proposed by Agrawal and Pati. We obtain an optimal way to partition some W-states of multi-qubit systems into two subsystems, such that the entanglement between them achieves maximum value.

  8. Aluminium in human sweat.

    Science.gov (United States)

    Minshall, Clare; Nadal, Jodie; Exley, Christopher

    2014-01-01

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

  9. Human exposure to aluminium.

    Science.gov (United States)

    Exley, Christopher

    2013-10-01

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

  10. Protocol for multi-party superdense coding by using multi-atom in cavity QED

    Institute of Scientific and Technical Information of China (English)

    Tan Jia; Fang Mao-Fa

    2006-01-01

    We present a protocol for multi-party superdense coding by using multi-atom in cavity quantum electrodynamics (QED). It is shown that, with a highly detuned cavity mode and a strong driving field, the protocol is insensitive to both cavity decay and thermal field. It is even certain to identify GHZ states via detecting the atomic states. Therefore we can realize the quantum dense coding in a simple way in the multiparty system.

  11. The generation of Entangled Qudits and their Application in Probabilistic Superdense Coding

    Institute of Scientific and Technical Information of China (English)

    Lin Qing

    2009-01-01

    @@ A scheme of the generation of entangled qutrits is presented, and then is generalized to entangled ququads and entangled qudits. With the entangled qutrits, an experimental scheme of probability superdense coding with only linear optical elements is proposed. It is shown that this scheme will be suitable for the entangled ququads, even for the entangled qudits if some nonlinearity is used. This scheme is feasible in the laboratory with the current experimental technology.

  12. Spherical configuration of a super-dense hot compact object with particular EoS

    CERN Document Server

    Tito, E P

    2016-01-01

    The equation of state (EoS) $P = P (\\rho, ...)$ -- pressure as a function of density and other thermodynamical quantities -- is what generates particularities of mass--radius distribution $M (R)$ for super--dense compact stellar bodies, the remnants of cosmic cataclysms. In view of recent nuclear experiments, we propose one particular EoS, which admits the critical state characterized by density $\\rho_c$ and temperature $T_c$, and which under certain conditions permits a radial distribution of the super--dense matter in "liquid" phase. We establish such conditions and demonstrate that a stable configuration is indeed possible (only) for temperatures smaller than the critical one. Using Tolman--Oppenheimer--Volkoff equations for hydrostatic equilibrium, we derive the mass--radius relation for the super--dense compact objects with masses smaller than the Sun, $M \\ll M_{\\odot}$. The obtained results are within the constraints established by both heavy--ion collision experiments and theoretical studies of neutron...

  13. Superdense Coding over Optical Fiber Links with Complete Bell-State Measurements

    Science.gov (United States)

    Williams, Brian P.; Sadlier, Ronald J.; Humble, Travis S.

    2017-02-01

    Adopting quantum communication to modern networking requires transmitting quantum information through a fiber-based infrastructure. We report the first demonstration of superdense coding over optical fiber links, taking advantage of a complete Bell-state measurement enabled by time-polarization hyperentanglement, linear optics, and common single-photon detectors. We demonstrate the highest single-qubit channel capacity to date utilizing linear optics, 1.665 ±0.018 , and we provide a full experimental implementation of a hybrid, quantum-classical communication protocol for image transfer.

  14. Controlled quantum secure direct communication using a non-symmetric quantum channel with quantum superdense coding

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Yan [School of Physic and Optoelectronic, Dalian University of Technology, Dalian 116024 (China)]. E-mail: xia-208@163.com; Song, He-Shan [School of Physic and Optoelectronic, Dalian University of Technology, Dalian 116024 (China)]. E-mail: hssong@dlut.edu.cn

    2007-04-23

    We present a controlled quantum secure direct communication protocol that uses a 2-dimensional Greenberger-Horne-Zeilinger (GHZ) entangled state and a 3-dimensional Bell-basis state and employs the high-dimensional quantum superdense coding, local collective unitary operations and entanglement swapping. The proposed protocol is secure and of high source capacity. It can effectively protect the communication against a destroying-travel-qubit-type attack. With this protocol, the information transmission is greatly increased. This protocol can also be modified, so that it can be used in a multi-party control system.

  15. 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.

  16. Generating multi-photon W-like states for perfect quantum teleportation and superdense coding

    Science.gov (United States)

    Li, Ke; Kong, Fan-Zhen; Yang, Ming; Ozaydin, Fatih; Yang, Qing; Cao, Zhuo-Liang

    2016-08-01

    An interesting aspect of multipartite entanglement is that for perfect teleportation and superdense coding, not the maximally entangled W states but a special class of non-maximally entangled W-like states are required. Therefore, efficient preparation of such W-like states is of great importance in quantum communications, which has not been studied as much as the preparation of W states. In this paper, we propose a simple optical scheme for efficient preparation of large-scale polarization-based entangled W-like states by fusing two W-like states or expanding a W-like state with an ancilla photon. Our scheme can also generate large-scale W states by fusing or expanding W or even W-like states. The cost analysis shows that in generating large-scale W states, the fusion mechanism achieves a higher efficiency with non-maximally entangled W-like states than maximally entangled W states. Our scheme can also start fusion or expansion with Bell states, and it is composed of a polarization-dependent beam splitter, two polarizing beam splitters and photon detectors. Requiring no ancilla photon or controlled gate to operate, our scheme can be realized with the current photonics technology and we believe it enable advances in quantum teleportation and superdense coding in multipartite settings.

  17. 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...

  18. Aluminium toxicity during regular haemodialysis.

    Science.gov (United States)

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

    1978-04-29

    In the west of Scotland the incidence of dialysis encephalopathy has been confined to three geographical areas where the concentration of aluminium in the water supply is greatly increased owing to the addition of aluminium sulphate. Eight patients with encephalopathy who dialysed at home in these areas had greatly increased serum aluminium concentrations, and a significant correlation was found between serum aluminium concentrations and the concentrations of aluminium in the water supply. This study provides further evidence that the dialysis encephalopathy syndrome is due to aluminium intoxication, the major source of aluminium being the water supply from which dialysis fluid prepared.

  19. 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...

  20. Search for decays of superdense nuclei in a two-meter propane chamber

    Energy Technology Data Exchange (ETDEWEB)

    Abdivaliev, A. (Leninabadskij Gosudarstvennyj Pedagogicheskij Inst. (USSR)); Zubarev, A.N.; Korzhev, N.A.; Kochurov, A.G.; Nikitin, A.V.; Pechenov, V.N.; Smirnov, N.A.; Sokolov, V.P.; Solov' ev, M.I.; Troyan, Yu.A. (Joint Inst. for Nuclear Research, Dubna (USSR))

    1981-10-01

    The upper limits of the cross sections for formation of superdense nuclei are determined. They lie between 5x10/sup -33/ and 10/sup -28/ cm/sup 2/ for /sub 28/Ni/sup 58/, /sub 82/Pb/sup 208/, /sub 29/Cu/sup 63/, /sub 73/Ta/sup 181/ and /sub 6/C/sup 12/ targets irradiated by 1.90, 3.36 or 9.86 GeV/c protons, 0.95 GeV/c per nucleon ..cap alpha..-particles and 3.36 GeV/c per nucleon carbon nuclei. Decay particles with energies exceeding 16.4 MeV were searched for.

  1. High-capacity three-party quantum secret sharing with superdense coding

    Institute of Scientific and Technical Information of China (English)

    Gu Bin; Li Chuan-Qi; Xu Fei; Chen Yu-Lin

    2009-01-01

    This paper presents a scheme for high-capacity three-party quantum secret sharing with quantum superdense coding, following some ideas in the work by Liu et al (2002 Phys. Rev. A 65 022304) and the quantum secret sharing scheme by Deng et al (2008 Phys. Left. A 372 1957). Instead of using two sets of nonorthogonal states, the boss Alice needs only to prepare a sequence of Einstein-Podolsky-Rosen pairs in d-dimension. The two agents Bob and Charlie encode their information with dense coding unitary operations, and security is checked by inserting decoy photons. The scheme has a high capacity and intrinsic efficiency as each pair can carry 21bd bits of information, and almost all the pairs can be used for carrying useful information.

  2. Quantum secure direct communication network with superdense coding and decoy photons

    Energy Technology Data Exchange (ETDEWEB)

    Deng Fuguo [Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Beijing Normal University, Beijing 100875 (China); Li Xihan [Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Beijing Normal University, Beijing 100875 (China); Li Chunyan [Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Beijing Normal University, Beijing 100875 (China); Zhou Ping [Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Beijing Normal University, Beijing 100875 (China); Zhou Hongyu [Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Beijing Normal University, Beijing 100875 (China)

    2007-07-15

    A quantum secure direct communication network scheme is proposed with quantum superdense coding and decoy photons. The servers on a passive optical network prepare and measure the quantum signal, i.e. a sequence of the d-dimensional Bell states. After confirming the security of the photons received from the receiver, the sender codes his secret message on them directly. For preventing a dishonest server from eavesdropping, some decoy photons prepared by measuring one photon in the Bell states are used to replace some original photons. One of the users on the network can communicate to any other one. This scheme has the advantage of high capacity, and it is more convenient than others as only a sequence of photons is transmitted in quantum line.

  3. Lewis acid fragmentation of a lithium aryloxide cage: generation of new heterometallic aluminium-lithium species.

    Science.gov (United States)

    Muñoz, Ma Teresa; Urbaneja, Carmen; Temprado, Manuel; Mosquera, Marta E G; Cuenca, Tomás

    2011-11-14

    Heterometallic aluminium-lithium species were prepared by the fragmentation reaction of the hexametallic cage compound [Li{2,6-(MeO)(2)C(6)H(3)O}](6) (1) with alkyl aluminium derivatives. Depending on the aluminium precursor, the species formed present different nuclearities in the solid state as shown by single crystal X-ray analysis. Spectroscopic and computational studies have been performed to study the nuclearity of the synthesized compounds in solution.

  4. 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.

  5. Superdense matter

    Indian Academy of Sciences (India)

    Thomas Schäfer

    2003-04-01

    We review recent work on the phase structure of QCD at very high baryon density. We introduce the phenomenon of color superconductivity and discuss the use of weak coupling methods. We study the phase structure as a function of the number of flavors and their masses. We also introduce effective theories that describe low energy excitations at high baryon density. Finally, we comment on the possibility of kaon condensation at very large baryon density.

  6. SURFACE MELTING OF ALUMINIUM ALLOYS

    OpenAIRE

    Veit, S.; Albert, D; Mergen, R.

    1987-01-01

    The wear properties of aluminium base alloys are relatively poor. Laser surface melting and alloying has proved successful in many alloy systems as a means of significantly improving the surface properties. The present work describes experiments designed to establish the scope of laser treatment of aluminium alloys. Aluminium does not absorb CO2 laser light as well as other metals which necessitated first a general study of absorption caotings. Aluminium alloys offer fewer opportunities than ...

  7. The cellular toxicity of aluminium.

    Science.gov (United States)

    Exley, C; Birchall, J D

    1992-11-07

    Aluminium is a serious environmental toxicant and is inimical to biota. Omnipresent, it is linked with a number of disorders in man including Alzheimer's disease, Parkinson's dementia and osteomalacia. Evidence supporting aluminium as an aetiological agent in such disorders is not conclusive and suffers principally from a lack of consensus with respect to aluminium's toxic mode of action. Obligatory to the elucidation of toxic mechanisms is an understanding of the biological availability of aluminium. This describes the fate of and response to aluminium in any biological system and is thus an important influence of the toxicity of aluminium. A general theme in much aluminium toxicity is an accelerated cell death. Herein mechanisms are described to account for cell death from both acute and chronic aluminium challenges. Aluminium associations with both extracellular surfaces and intracellular ligands are implicated. The cellular response to aluminium is found to be biphasic having both stimulatory and inhibitory components. In either case the disruption of second messenger systems is observed and GTPase cycles are potential target sites. Specific ligands for aluminium at these sites are unknown though are likely to be proteins upon which oxygen-based functional groups are orientated to give exceptionally strong binding with the free aluminium ion.

  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. Solution-combustion synthesized aluminium-doped spinel (LiAl(subx)Mn(sub2-x)O(sub4) as a high-performance lithium-ion battery cathode material

    CSIR Research Space (South Africa)

    Kebede, MA

    2015-06-01

    Full Text Available High-performing (LiAl(subx)Mn(sub2-x)O(sub4) (x = 0, 0.125, 0.25, 0.375, and 0.5) spinel cathode materials for lithium-ion battery were developed using a solution combustion method. The as-synthesized cathode materials have spinel cubic structure...

  10. Synthesis of silver nanotubes by electroless deposition in porous anodic aluminium oxide templates.

    Science.gov (United States)

    Zhang, Shu-Hong; Xie, Zhao-Xiong; Jiang, Zhi-Yuan; Xu, Xin; Xiang, Juan; Huang, Rong-Bin; Zheng, Lan-Sun

    2004-05-07

    An electroless deposition method has been employed for the synthesis of silver nanotubes using porous anodic aluminium oxide as templates, by which high-yield silver nanotubes with length over ten microns have been synthesized.

  11. Superdense Coding with GHZ and Quantum Key Distribution with W in the ZX-calculus

    Directory of Open Access Journals (Sweden)

    Anne Hillebrand

    2012-10-01

    Full Text Available Quantum entanglement is a key resource in many quantum protocols, such as quantum teleportation and quantum cryptography. Yet entanglement makes protocols presented in Dirac notation difficult to verify. This is why Coecke and Duncan have introduced a diagrammatic language for quantum protocols, called the ZX-calculus. This diagrammatic notation is both intuitive and formally rigorous. It is a simple, graphical, high level language that emphasises the composition of systems and naturally captures the essentials of quantum mechanics. In the author's MSc thesis it has been shown for over 25 quantum protocols that the ZX-calculus provides a relatively easy and more intuitive presentation. Moreover, the author embarked on the task to apply categorical quantum mechanics on quantum security; earlier works did not touch anything but Bennett and Brassard's quantum key distribution protocol, BB84. Superdense coding with the Greenberger-Horne-Zeilinger state and quantum key distribution with the W-state are presented in the ZX-calculus in this paper.

  12. Aluminium in human breast tissue.

    Science.gov (United States)

    Exley, Christopher; Charles, Lisa M; Barr, Lester; Martin, Claire; Polwart, Anthony; Darbre, Philippa D

    2007-09-01

    Aluminium is omnipresent in everyday life and increased exposure is resulting in a burgeoning body burden of this non-essential metal. Personal care products are potential contributors to the body burden of aluminium and recent evidence has linked breast cancer with aluminium-based antiperspirants. We have used graphite furnace atomic absorption spectrometry (GFAAS) to measure the aluminium content in breast biopsies obtained following mastectomies. The aluminium content of breast tissue and breast tissue fat were in the range 4-437 nmol/g dry wt. and 3-192 nmol/g oil, respectively. The aluminium content of breast tissue in the outer regions (axilla and lateral) was significantly higher (P=0.033) than the inner regions (middle and medial) of the breast. Whether differences in the regional distribution of aluminium in the breast are related to the known higher incidence of tumours in the outer upper quadrant of the breast remains to be ascertained.

  13. 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

  14. 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

  15. Ontwerpen en berekenen van aluminium constructies

    NARCIS (Netherlands)

    Soetens, F.

    1996-01-01

    De toepassing van aluminium in dragende constructies is succesvol, indien de gunstige eigenschappen van aluminium goed worden benut en er voor de minder gunstige eigenschappen een adequate constructieve oplossing wordt geboden. De toepassingsmogelijkheden van aluminium zijn de laatste jaren

  16. 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.

  17. 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...... 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...

  18. 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...... 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...

  19. 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.

  20. [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.

  1. 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

  2. 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

  3. Aluminium in Drinkwater: voorkomen, herkomst en gezondheidsaspecten

    NARCIS (Netherlands)

    Versteegh JFM; de Boer JLM; van den Velde-Koerts T

    1992-01-01

    Aluminium can occur in drinking water because of the application of aluminium salts as a coagulant in the treatment of drinking water. In the Netherlands mostly iron salts are used instead of aluminium. Besides this aluminium can be present in the source for drinking water. In shallow groundwater

  4. Aluminium in Drinkwater: voorkomen, herkomst en gezondheidsaspecten

    NARCIS (Netherlands)

    Versteegh JFM; de Boer JLM; van den Velde-Koerts T

    1992-01-01

    Aluminium can occur in drinking water because of the application of aluminium salts as a coagulant in the treatment of drinking water. In the Netherlands mostly iron salts are used instead of aluminium. Besides this aluminium can be present in the source for drinking water. In shallow groundwater

  5. Dispersion strengthening of aluminium-aluminium-oxide products

    DEFF Research Database (Denmark)

    Hansen, Niels

    1970-01-01

    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...... and decreasing particle size of the dispersed particles. A general expression for k1 was derived for the relationship between the dislocation density and the strain in dispersion-strengthened products...

  6. 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.

  7. 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.

  8. Synthesis of Aluminium Nanoparticles in A Water/Polyethylene Glycol Mixed Solvent using μ-EDM

    Science.gov (United States)

    Sahu, R. K.; Hiremath, Somashekhar S.

    2017-08-01

    Nanoparticles present a practical way of retaining the results of the property at the atomic or molecular level. Due to the recent use of nanoparticles in scientific, industrial and medical applications, synthesis of nanoparticles and their characterization have become considerably important. Currently, aluminium nanoparticles have attracted significant research attention because of their reasonable cost, unique properties and interdisciplinary emerging applications. The present paper reports the synthesis of aluminium nanoparticles in the mixture of Deionized water (DI water) and Polyethylene Glycol (PEG) using a developed micro-Electrical Discharge Machining (μ-EDM) method. PEG was used as a stabilizer to prevent nanoparticles from agglomeration produced during the μ -EDM process. The synthesized aluminium nanoparticles were examined by Transmission Electron Microscopy (TEM), Energy Dispersive Analysis by X-rays (EDAX) and Selected Area Electron Diffraction (SAED) pattern to determine their size, shape, chemical nature and crystal structure. The average size of the polyhedral aluminium nanoparticles is found to be 196 nm.

  9. 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.

  10. 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%.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1955-07-01

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

  12. Plasma treatment of aluminium dross

    Energy Technology Data Exchange (ETDEWEB)

    Drouet, M.; Meunier, J.; Handfield, M. [Hydro-Quebec, Montreal, PQ (Canada)

    1992-12-31

    The treatment process that produces dross was described. Dross is a major by-product of all processes involving molten aluminium and is formed on the surface of the molten metal as it reacts with the furnace atmosphere. Up to 10% of the molten metal can be turned into dross. White dross is produced by melting primary aluminium. Black dross contains contaminants such as salt fluxes and other metals. The aluminium in the dross is usually recovered in oil or gas-fired rotary furnaces when fluxing salts are added to the load to increase the amount of aluminium recovered. This process produces a secondary dross called salt slag containing alumina, salts, impurities and a small amount of aluminium. One of the goals of plasma arc technologies has been to develop high temperature processes which would either avoid the use of salts in the treatment of white dross or provide a means of transforming the black dross into a landfill or salable product. 5 refs., 1 tab., 2 figs.

  13. Aluminium bismuthate nanorods and the electrochemical performance for detection of tartaric acid

    Energy Technology Data Exchange (ETDEWEB)

    Pei, L.Z., E-mail: lzpei@ahut.edu.cn [Key Lab of Materials Science and Processing of Anhui Province, School of Materials Science and Engineering, Anhui University of Technology, Ma' anshan, Anhui 243002 (China); Wei, T.; Lin, N.; Fan, C.G. [Key Lab of Materials Science and Processing of Anhui Province, School of Materials Science and Engineering, Anhui University of Technology, Ma' anshan, Anhui 243002 (China); Yang, Zao, E-mail: yangzao888@tom.com [National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, Sichuan 610064 (China)

    2016-09-15

    Aluminium bismuthate nanorods had been synthesized by a facile hydrothemral method. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations showed that the lengh and diameter were 2–10 μm and 50–200 nm, respectively. X-ray diffraction (XRD) and high-resolution TEM (HRTEM) showed that the nanorods were composed of single crystalline orthorhombic Al{sub 4}Bi{sub 2}O{sub 9} phase. The aluminium bismuthate nanorods could be explained by the nucleation and crystalline growth process based on the products obtained from different hydrothermal conditions. Aluminium bismuthate nanorods modified glassy carbon electrode (GCE) was fabricated for the electrochemical detection of tartaric acid (TA) in neutral solution. A pair of semi-reversible redox peaks located at −0.08 V and −0.53 V, respectively were observed. The current intensity of the cyclic voltammogram (CV) peak increased linearly obviously with increasing the scan rate and TA concentration. The detection limit and linear range were 0.64 μM and 0.001–2 mM, respectively with the correlation coefficient of 0.995. The aluminium bismuthate nanorods modified GCE had good reproducibility and stability for the detection of TA. - Highlights: • Aluminium bismuthate nanorods were synthesized by a facile hydrothermal process. • The size of aluminium bismuthate nanorods could be controlled by growth conditions. • Aluminium bismuthate nanorods showed good electrochemical performance for the detection of tartaric acid. • Aluminium bismuthate nanorods modified GCE had good reproducibility and stability.

  14. 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...

  15. Design and analysis of aluminium brdiges

    NARCIS (Netherlands)

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

    2004-01-01

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

  16. 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.

  17. Waveform synthesizer

    Science.gov (United States)

    Franks, Larry A.; Nelson, Melvin A.

    1981-01-01

    A method of producing optical and electrical pulses of desired shape. An optical pulse of arbitrary but defined shape illuminates one end of an array of optical fiber waveguides of differing lengths to time differentiate the input pulse. The optical outputs at the other end of the array are combined to form a synthesized pulse of desired shape.

  18. Effect of hydrogen on aluminium and aluminium alloys: A review

    DEFF Research Database (Denmark)

    Ambat, Rajan; Dwarakadasa, E.S.

    1996-01-01

    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...

  19. 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.

  20. 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

  1. 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...

  2. Comparative Study of Leaching of Aluminium from Aluminium, Clay, Stainless Steel, and Steel Cooking Pots

    OpenAIRE

    Odularu, A. T.; P. A. Ajibade; P.C. Onianwa

    2013-01-01

    Analyses on the absorption of aluminium by rice boiled in distilled water in a variety of containers, such as old and new aluminium pots, clay receptacles, stainless steel pots, and steel pots, were carried out. 10 g of rice was taken as a representative sample. Colorimetric analysis of classical methods was used to determine the concentration of aluminium. The control for aluminium was 350 ± 130 μg/g. The new aluminium pots had a concentration of 126 ± 64 μg/g, old aluminium pots had 314 ± 1...

  3. Searching for new aluminium chelating agents: a family of hydroxypyrone ligands.

    Science.gov (United States)

    Toso, Leonardo; Crisponi, Guido; Nurchi, Valeria M; Crespo-Alonso, Miriam; Lachowicz, Joanna I; Mansoori, Delara; Arca, Massimiliano; Santos, M Amélia; Marques, Sérgio M; Gano, Lurdes; Niclós-Gutíerrez, Juan; González-Pérez, Josefa M; Domínguez-Martín, Alicia; Choquesillo-Lazarte, Duane; Szewczuk, Zbigniew

    2014-01-01

    Attention is devoted to the role of chelating agents in the treatment of aluminium related diseases. In fact, in spite of the efforts that have drastically reduced the occurrence of aluminium dialysis diseases, they so far constitute a cause of great medical concern. The use of chelating agents for iron and aluminium in different clinical applications has found increasing attention in the last thirty years. With the aim of designing new chelators, we synthesized a series of kojic acid derivatives containing two kojic units joined by different linkers. A huge advantage of these molecules is that they are cheap and easy to produce. Previous works on complex formation equilibria of a first group of these ligands with iron and aluminium highlighted extremely good pMe values and gave evidence of the ability to scavenge iron from inside cells. On these bases a second set of bis-kojic ligands, whose linkers between the kojic chelating moieties are differentiated both in terms of type and size, has been designed, synthesized and characterized. The aluminium(III) complex formation equilibria studied by potentiometry, electrospray ionization mass spectroscopy (ESI-MS), quantum-mechanical calculations and (1)H NMR spectroscopy are here described and discussed, and the structural characterization of one of these new ligands is presented. The in vivo studies show that these new bis-kojic derivatives induce faster clearance from main organs as compared with the monomeric analog. © 2013.

  4. Bumblebee pupae contain high levels of aluminium.

    Directory of Open Access Journals (Sweden)

    Christopher Exley

    Full Text Available 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.

  5. 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.

  6. 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.

  7. Pengaruh Suhu Terhadap % Recovery Aluminium pada Pengolahan Campuran Aluminium Oksida yang Terakumulasi pada Permukaan Aluminium Cair (DROSS)

    OpenAIRE

    Ulpa, Dwi Raafiah

    2010-01-01

    Dross adalah kotoran yang mengapung di atas permukaan aluminium cair yang terbentuk akibat proses penambahan fluks ke dalam aluminium cair. Suhu merupakan variabel yang sangat berpengaruh dalam pengolahan dross. Telah dilakukan pengamatan pada pengolahan dross dengan cara sentrifugasi yang melibatkan variasi suhu (772oC – 802oC). Alat yang digunakan dalam pengolahan dross adalah alat pengolahan dross. Hasil pengamatan menunjukkan pada suhu maksimum 802oC menghasilkan recovery aluminium maksim...

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

    OpenAIRE

    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...

  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. 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.

  12. 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.

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

    Science.gov (United States)

    Seredych, Mykola; Bandosz, Teresa J

    2008-08-01

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

  14. Partial molar volumes of aluminium chloride, aluminium sulphate and aluminium nitrate in water-rich binary aqueous mixtures of tetrahydrofuran

    Directory of Open Access Journals (Sweden)

    R. C. Thakur

    2014-12-01

    Full Text Available Partial molar volumes of aluminium chloride, aluminium sulphate and aluminium nitrate have been determined in water rich binary aqueous mixtures of tetrahydrofuran (5, 10, 15, 20% by weight of tetrahydrofuran with the help of density measurements. The density measurements were made by using Ward and Millero method and results have been analysed by Masson’s equation and interpreted in terms of ion-ion or ion –solvent interactions. The partial molar volumes vary with temperature as a power series of temperature. Structure making or breaking capacities of aluminium salts have been inferred from the sign à2/ Φvo p i.e second derivative of partial molar volume with respect to temperature at constant pressure. The aluminium salts have been found as structure breakers in binary aqueous mixture of tetrahydrofuran.

  15. 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...

  16. Rapidly solidified aluminium for optical applications

    NARCIS (Netherlands)

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

    2008-01-01

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

  17. 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.

  18. 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%.

  19. Novel Synthesis of Aluminium Oxide Nanofibers

    Science.gov (United States)

    2001-11-01

    UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADP012177 TITLE: Novel Synthesis of Aluminium Oxide Nanofibers DISTRIBUTION...ADP012174 thru ADP012259 UNCLASSIFIED Mat. Res. Soc. Symp. Proc. Vol. 703 © 2002 Materials Research Society V1.8 Novel Synthesis of Aluminium Oxide Nanofibers

  20. Electron Conditioning of Technical Aluminium Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Le Pimpec, F

    2004-09-02

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

  1. Locale instabiliteit van aluminium constructiedelen bij brand

    NARCIS (Netherlands)

    Maljaars, J.; Soetens, F.

    2006-01-01

    Dragende constructiedelen van aluminium legeringen, zoals toegepast in bouwconstructies maar ook in schepen en offshore platforms, moeten zodanig ontworpen worden dat mensen veilig kunnen vluchten als er brand uitbreekt. Door de lage smelttemperatuur van aluminium vraagt brand de nodige aandacht in

  2. 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

  3. Aluminium Diphosphamethanides: Hidden Frustrated Lewis Pairs.

    Science.gov (United States)

    Styra, Steffen; Radius, Michael; Moos, Eric; Bihlmeier, Angela; Breher, Frank

    2016-07-04

    The synthesis and characterisation of two aluminium diphosphamethanide complexes, [Al(tBu)2 {κ(2) P,P'-Mes*PCHPMes*}] (3) and [Al(C6 F5 )2 {κ(2) P,P'-Mes*PCHPMes*}] (4), and the silylated analogue, Mes*PCHP(SiMe3 )Mes* (5), are reported. The aluminium complexes feature four-membered PCPAl core structures consisting of diphosphaallyl ligands. The silylated phosphine 5 was found to be a valuable precursor for the synthesis of 4 as it cleanly reacts with the diaryl aluminium chloride [(C6 F5 )2 AlCl]2 . The aluminium complex 3 reacts with molecular dihydrogen at room temperature under formation of the acyclic σ(2) λ(3) ,σ(3) λ(3) -diphosphine Mes*PCHP(H)Mes* and the corresponding dialkyl aluminium hydride [tBu2 AlH]3 . Thus, 3 belongs to the family of so-called hidden frustrated Lewis pairs.

  4. Hydroxyaluminosilicates and acute aluminium toxicity in fish

    Science.gov (United States)

    Exley; Pinnegar; Taylor

    1997-11-21

    The essentiality of silicon in biology might be explained in the terms of its chemistry with aluminium. In a previous study we demonstrated the elimination of acute aluminium toxicity in fish by silicon. We suggested that the reaction of silicic acid with aluminium to form hydroxyaluminosilicates reduced the biological availability, and hence toxicity, of aluminium. Though assumed in a burgeoning number of studies and contended in others this detoxification mechanism has remained unproven. Herein we have tested the toxicity of hydroxyaluminosilicates in fish and in doing so we have provided evidence which strongly supports a role for hydroxyaluminiosilicates in the elimination of acute aluminium toxicity in fish by silicon.Copyright 1997 Academic Press Limited Copyright 1997 Academic Press Limited

  5. 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

  6. Alveolar proteinosis associated with aluminium dust inhalation.

    Science.gov (United States)

    Chew, R; Nigam, S; Sivakumaran, P

    2016-08-01

    Secondary alveolar proteinosis is a rare lung disease which may be triggered by a variety of inhaled particles. The diagnosis is made by detection of anti-granulocyte-macrophage colony-stimulating factor antibodies in bronchoalveolar lavage fluid, which appears milky white and contains lamellar bodies. Aluminium has been suggested as a possible cause, but there is little evidence in the literature to support this assertion. We report the case of a 46-year-old former boilermaker and boat builder who developed secondary alveolar proteinosis following sustained heavy aluminium exposure. The presence of aluminium was confirmed both by histological examination and metallurgical analysis of a mediastinal lymph node. Despite cessation of exposure to aluminium and treatment with whole-lung lavage which normally results in improvements in both symptoms and lung function, the outcome was poor and novel therapies are now being used for this patient. It may be that the natural history in aluminium-related alveolar proteinosis is different, with the metal playing a mediating role in the disease process. Our case further supports the link between aluminium and secondary alveolar proteinosis and highlights the need for measures to prevent excessive aluminium inhalation in relevant industries. © The Author 2016. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Aluminium in Biological Environments: A Computational Approach

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    1972-01-01

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

  9. Analysis of Elemental and Isotopic Composition of a Substance Obtained in Experiments on Energy Concentration in a Solid-State Superdense Plasma

    CERN Document Server

    Adamenko, S V

    2003-01-01

    We present the results of the experimental study on synthesis of a wide range of isotopes in a superdense plasma. The initial conditions necessary for plasma bunch formation were provided by specially organized coherent impact on a solid target with a total energy up to 1 kJ. More than 4000 shots were performed with various targets made of light, medium, and heavy elements. Subsequent analysis of the products of the target explosion reveals the presence of a wide range of elements absent in the initial materials. Elements with nuclei three and more times heavier than the nucleus of the target main element are detected in the products. The isotopic composition of the produced elements significantly differs from the natural one. The presence of unknown superheavy elements at the border of the periodic table and beyond it was detected by several different spectroscopic methods of elemental and isotopic analyzes.

  10. Characteristics of cast and welded aluminium nodes

    Energy Technology Data Exchange (ETDEWEB)

    Oedegaard, J.; Polanco, M.; Syvertsen, F.; Sund, H. [SINTEF, Trondheim (Norway). Materials Technology

    2000-07-01

    It has been demonstrated that sand cast aluminium nodes can be produced with properties that gives competitive energy absorption capacity compared with welded aluminium nodes. Sand cast nodes could be mass-produced to a low cost and with properties that should be competitive to the properties of fusion welded nodes. This may open for simpler and more cost-effective joint alternatives when production of aluminium space-frames and subassemblies are in focus. Cast nodes joined to extruded members by adhesive bonding could be one example. (orig.)

  11. Thermal transformations of aluminium-aluminium oxide systems in nanosize layers

    OpenAIRE

    2007-01-01

    Aluminium film of more than 2 nm thick indicates, but less than 2 nm do not indicate characteristic absorption and reflection bands for aluminium in range ?=190...1100 nm. By spectrophotometric, gravimetric and microscopic methods it is stated that thickness, mass and absorption, reflection spectrum of aluminium films (d=2...200 nm) undergo considerable transformations as a result of heat treatment in an interval of temperatures 373...600 K during 1...140 min in atmospheric conditions. Kineti...

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

    OpenAIRE

    2014-01-01

    Introduction Aluminium is a known neurotoxin and occupational exposure to aluminium has been implicated in neurological disease including Alzheimer’s disease. Here we present the first comprehensive and unequivocal data demonstrating significantly elevated brain aluminium content in an individual occupationally exposed to aluminium. Case presentation A 66-year-old Caucasian man who died with Alzheimer’s disease showed significantly elevated brain aluminium content, 2.98 (2.73) μg/g dry weight...

  13. 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.

  14. The meaning of aluminium exposure on human health and aluminium-related diseases.

    Science.gov (United States)

    Crisponi, Guido; Fanni, Daniela; Gerosa, Clara; Nemolato, Sonia; Nurchi, Valeria M; Crespo-Alonso, Miriam; Lachowicz, Joanna I; Faa, Gavino

    2013-02-01

    The aim of this review is to attempt to answer extremely important questions related to aluminium-related diseases. Starting from an overview on the main sources of aluminium exposure in everyday life, the principal aspects of aluminium metabolism in humans have been taken into consideration in an attempt to enlighten the main metabolic pathways utilised by trivalent metal ions in different organs. The second part of this review is focused on the available evidence concerning the pathogenetic consequences of aluminium overload in human health, with particular attention to its putative role in bone and neurodegenerative human diseases.

  15. 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.

  16. 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.

  17. BIOSORPTION OF ALUMINIUM FROM SOLUTION BY DEAD ...

    African Journals Online (AJOL)

    biosorption of aluminium ions from solution was also evaluated. The result ... aqueous solution. The effect of pH on ... identified as Penicillium chrysogenum, Aspergillus niger,. Aspergillus ..... chloride macroquantities on the anion exchanger ...

  18. Annual reports in inorganic and general syntheses 1974

    CERN Document Server

    Niedenzu, Kurt

    1975-01-01

    Annual Reports in Inorganic and General Syntheses-1974 presents an organized annual summary of synthetic developments in inorganic chemistry and its related areas. The book discusses the chemistry of simple and complex metal hydrides of main groups I, II, and III, boron, aluminium, gallium, indium, thallium, silicon, germanium, tin, lead, phosphorus, arsenic, antimony, bismuth, chalcogens, halogens, and pseudohalogens. The text also describes the chemistry of scandium, yttrium, lanthanides, actinides, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, ma

  19. Annual reports in inorganic and general syntheses 1973

    CERN Document Server

    Niedenzu, Kurt

    1974-01-01

    Annual Reports in Inorganic and General Syntheses-1973 presents an organized annual summary of synthetic developments in inorganic chemistry and its related areas. The book covers the synthetic aspects and structural or mechanistic features of elements, including the main group hydrides, alkali and alkaline earth elements, boron, aluminium, gallium, indium, thallium, silicon, germanium, tin, and lead, nitrogen, phosphorus, arsenic, antimony, bismuth, chalcogens, halogens and pseudohalogens, and noble gases. The text also discusses the synthetic aspects and structural or mechanistic features of

  20. 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.

  1. Effects of aluminium in acidifield aquatic ecosystems

    OpenAIRE

    Rosseland, B. O.; Brandrud, T.E.; Raddum, G.

    1992-01-01

    In the acidic aquatic environment, pH, aluminium and calcium are still the three most importent factors to explain losses of biota. The inorganic (labile) monomeric species of aluminium acts as a toxic agent on gill-breathing animals such as fish and invertebrates, by causing loss of plasma and haemolymph ions leading to osmorereulatory failure. A series of different effects on all levels of organization within an organism are described, as well as important population resposes. In contrast o...

  2. 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....

  3. 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.

  4. Bumblebee Pupae Contain High Levels of Aluminium

    OpenAIRE

    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 mic...

  5. Bumblebee pupae contain high levels of aluminium

    OpenAIRE

    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 mic...

  6. Perfect Teleportation and Superdense Coding with a Genuine Entangled Five-qubit State%基于五离子最大纠缠态的优化隐形传态和超密集编码

    Institute of Scientific and Technical Information of China (English)

    范学涛; 於亚飞; 张智明

    2011-01-01

    We propose a scheme to generate a genuine five-qubit entangled state, and use this state for perfect teleportation of an arbitrary two-qubit state and superdense coding. The capacity of superdense coding of the state reaches the "Holevo bound", which means that five classical bits can be transmitted by sending three qubits.%我们提出了一个制备五离子最大纠缠态的方案,并利用该纠缠态实现任意两量子比特的隐形传送和超密集编码.超密集编码的信息容量满足"Holevo bound",这意味着通过发送三个量子比特可以传送五个经典比特的信息.

  7. 超声处理原位合成TiAl3/7075铝基复合材料的动力学分析%Kinetic analysis of in situ synthesized TiAl3/7075 aluminium alloy matrix composites via ultrasonic treatment

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    TiAl3/7075 composites were fabricated by in situ synthesis via ultrasonic treatment. A kinetic model of the reaction process acted by ultrasonic wave was built with mathematical calculation. The calculations show that the reaction time comparing with that of no ultrasonic treatment is greatly reduced. Some influencing factors on the reaction rate were analyzed. The results show that granular TiAl3 phases present in the composites and distribute homogeneously. Ultrasonic oscillation can increase the diffusion coefficient of aluminium atom,decrease the thickness of boundary layer and the size of titanium particle,all these accelerates the velocity of reaction.%  采用超声复合原位合成技术制备 TiAl3/7075复合材料,建立在超声处理情况下的动力学模型,并进行数值计算。计算表明,与未超声处理相比较,反应时间大幅度缩短。分析影响反应速率的因素,结果表明:在超声波作用下,获得颗粒状的 TiAl3相且弥散分布;超声作用增大 Al 原子的扩散系数、减小边界层的厚度及 Ti 颗粒的大小,以致加快反应速度。

  8. 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.

  9. 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.

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

    Science.gov (United States)

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

    2012-01-01

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

  11. Synthesis and characterization of yttrium aluminium garnet (YAG powders

    Directory of Open Access Journals (Sweden)

    Magdalena Zarzecka-Napierala

    2007-12-01

    Full Text Available In this paper synthesis and characterization of YAG powders, prepared by a process based on complexing properties of citric acid, was reported. Influence of citric acid estrification induced by 2-propanol or ethylene glycol on the system homogeneity was investigated. These reagents were introduced to aqueous solution of yttrium and aluminium nitrates. A variety of powders from Al2O3-Y2O3 system with different phase composition were obtained by altering the citrate to nitrate ratio. Evolution of the powders phase composition vs. temperature was investigated using DTA/TG, XRD, and FT-IR methods. The most interesting results were observed in case of the citric acid–propanol–relative nitrates system. The mole ratio of these reagents equal to 1:2.5:2.5 (nitrates (Al,Y:citric acid:2-propanol allowed to synthesize pure YAG phase powders at temperature as low as 950°C.

  12. Aluminium toxicity in winter wheat

    Directory of Open Access Journals (Sweden)

    Szabó A.

    2015-01-01

    Full Text Available Aluminium is the most frequent metal of the earth crust; it occurs mainly as biologically inactive, insoluble deposit. Environmental problems, industrial contaminations and acid rains increase the soil acidity, leading to the mobilization of Al. Half of the world’s potential arable lands are acidic; therefore, Al-toxicity decreases crop productivity. Wheat is a staple food for 35% of the world population. The effects of Al-stress (0.1 mM were studied on winter wheat; seedlings were grown hydroponically, at acidic pH. After two weeks, the root weight was decreased; a significant difference was found in the P- and Ca-content. The shoot weight and element content changed slightly; Al-content in the root was one magnitude higher than in the shoot, while Al-translocation was limited. The root plasma membrane H+-ATPase has central role in the uptake processes; Al-stress increased the Mg2+-ATPase activity of the microsomal fraction.

  13. 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...

  14. Investigation of the formability of aluminium alloys at elevated temperatures

    Science.gov (United States)

    Tisza, M.; Budai, D.; Kovács, P. Z.; Lukács, Zs

    2016-11-01

    Aluminium alloys are more and more widely applied in car body manufacturing. Increasing the formability of aluminium alloys are one of the most relevant tasks in todays’ research topics. In this paper, the focus will be on the investigation of the formability of aluminium alloys concerning those material grades that are more widely applied in the automotive industry including the 5xxx and 6xxx aluminium alloy series. Recently, besides the cold forming of aluminium sheets the forming of aluminium alloys at elevated temperatures became a hot research topic, too. In our experimental investigations, we mostly examined the EN AW 5754 and EN AW 6082 aluminium alloys at elevated temperatures. We analysed the effect of various material and process parameters (e.g. temperature, sheet thickness) on the formability of aluminium alloys with particular emphasis on the Forming Limit Diagrams at elevated temperatures in order to find the optimum forming conditions for these alloys.

  15. 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.

  16. 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....

  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...... 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 Assisted Accelerated Growth of Oxide Layer on Aluminium Alloys

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  19. Steam Assisted Accelerated Growth of Oxide Layer on Aluminium Alloys

    OpenAIRE

    2013-01-01

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

  20. The non-destructive prediction of the aluminium content in pressed skulls of aluminium dross

    Directory of Open Access Journals (Sweden)

    Varužan Kevorkijan

    2012-12-01

    Full Text Available During production of primary and secondary aluminium, various amounts of aluminium dross, a mixture consisting of molten aluminium metal and different oxide compounds, is skimmed per tonne of molten metal. In order to preserve the maximum aluminium content in hot dross for further extraction, it is necessary to cool the dross (e.g. by pressing immediately after skimming. During pressing, the skimmed dross is transformed into so-called pressed skulls, convenient for storage, transport or further inhouse processing. Pressed skulls, which represent a valuable source of aluminium, are generally valued on a free-metal recovery basis. Therefore, it is important and useful to develop a method of fast and cost-effective non-destructive measurement of the free aluminium content in pressed skulls, independent of the technology of pressed skulls recycling. Following the theoretical considerations presented in this work, a practical industrial methodology was developed for non-destructive prediction of the amount of free aluminium in pressed skulls, wAl, based on non-destructive measurement of the density, ρ, of the pressed skulls.

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

    Science.gov (United States)

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

    2016-03-01

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

  2. 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

  3. [Aluminium allergy and granulomas induced by vaccinations for children].

    Science.gov (United States)

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

    2015-04-27

    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.

  4. 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....

  5. 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

  6. 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

  7. 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

  8. Aluminium hydroxide-induced granulomas in pigs

    DEFF Research Database (Denmark)

    Valtulini, S; Macchi, C; Ballanti, P

    2005-01-01

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

  9. The binding of phosphonic acids at aluminium oxide surfaces and correlation with passivation of aluminium flake.

    Science.gov (United States)

    Cooper, Rachel J; Camp, Philip J; Henderson, David K; Lovatt, Paul A; Nation, David A; Richards, Stuart; Tasker, Peter A

    2007-04-07

    Measurements of adsorption isotherms of a series of thirteen mono- and di-phosphonic acids have shown that these bind strongly to the surface of high surface area aluminium trihydroxide. The incorporation of such phosphonates into a suspension of aluminium flake in an aqueous medium, modelling the continuous phase of a water-based paint, greatly suppresses the evolution of hydrogen. Whilst strong binding of the phosphonate to aluminium oxides is an essential criterion for good passivation, other factors such as the hydrophobicity of the ligand are also important in suppressing hydrogen-evolution.

  10. Aluminium and the human breast.

    Science.gov (United States)

    Darbre, P D

    2016-06-01

    The human population is exposed to aluminium (Al) from diet, antacids and vaccine adjuvants, but frequent application of Al-based salts to the underarm as antiperspirant adds a high additional exposure directly to the local area of the human breast. Coincidentally the upper outer quadrant of the breast is where there is also a disproportionately high incidence of breast cysts and breast cancer. Al has been measured in human breast tissues/fluids at higher levels than in blood, and experimental evidence suggests that at physiologically relevant concentrations, Al can adversely impact on human breast epithelial cell biology. Gross cystic breast disease is the most common benign disorder of the breast and evidence is presented that Al may be a causative factor in formation of breast cysts. Evidence is also reviewed that Al can enable the development of multiple hallmarks associated with cancer in breast cells, in particular that it can cause genomic instability and inappropriate proliferation in human breast epithelial cells, and can increase migration and invasion of human breast cancer cells. In addition, Al is a metalloestrogen and oestrogen is a risk factor for breast cancer known to influence multiple hallmarks. The microenvironment is established as another determinant of breast cancer development and Al has been shown to cause adverse alterations to the breast microenvironment. If current usage patterns of Al-based antiperspirant salts contribute to causation of breast cysts and breast cancer, then reduction in exposure would offer a strategy for prevention, and regulatory review is now justified. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  11. 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.

  12. Amidinate aluminium complexes: synthesis, characterization and ring-opening polymerization of rac-lactide.

    Science.gov (United States)

    Qian, Feng; Liu, Keyin; Ma, Haiyan

    2010-09-14

    A series of aluminium alkyl complexes {PhC(NR')(NR'')}AlR(2) (4a-n, R' = 2,6-(i)Pr(2)C(6)H(3), 2,6-Me(2)C(6)H(3); R'' = aryl groups with various ortho-, para- or meta-substituents, tert-butyl; R = methyl, ethyl) bearing non-symmetrically N-substituted benzamidinate ligands were synthesized via the reaction of trialkylaluminium and the corresponding benzamidine proligands. Complex 5 bearing symmetric amidinate ligand was also obtained for comparison purposes. The X-ray diffraction studies of complexes 4b, 4c and 5 show in each case a distorted tetrahedral geometry around the aluminium center. All the amidinate aluminium complexes were found to catalyze the ring-opening polymerization (ROP) of rac-lactide with moderate activities. The steric and electronic characteristics of the ancillary ligands have a significant influence on the polymerization performance of the corresponding aluminium complexes. The introduction of electron-withdrawing substituents at the ortho-positions of N-phenyl ring of the ligands resulted in an obvious increase in catalytic activity. Complex 4b showed the highest activity among the investigated aluminium complexes due to the high electrophilicity of the metal center induced by the ortho-chloro substituents on the phenyl ring. The existence of ortho-substituents of small steric bulkiness is also beneficial for the increase of activity of these catalysts. However, further increase of steric hindrance of the ligands by introducing bulky ortho-substituents onto the phenyl moieties resulted in a decrease of activity and an increase in the isotactic bias of the obtained polylactides. The broad molecular weight distributions (PDI = 1.13-2.02) of the polymer samples indicated that the ROP of rac-lactide initiated by these complexes was not well-controlled.

  13. 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 crystallog......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...

  14. 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.).

  15. 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

  16. 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

  17. Aluminium: a natural adjuvant in Leishmania transmission via sand flies?

    Science.gov (United States)

    Maingon, Rhayza; Khela, Amandeep; Sampson, Christopher; Ward, Richard; Walker, Karen; Exley, Christopher

    2008-11-01

    Genetically identical Leishmania chagasi/infantum parasites cause both atypical cutaneous leishmaniasis and visceral leishmaniasis. In this report we have tested the first part of a hypothesis that states that the form of this disease that is manifested depends upon the adjuvant-like activity of aluminium of dietary origin accumulated in the salivary gland of the sand fly vector. In sand flies fed aluminium-supplemented sucrose we have used histochemistry to qualitatively identify aluminium in their salivary glands and graphite furnace atomic absorption spectrometry to quantify the aluminium content of dissected salivary glands. Aluminium may be acting as a natural adjuvant in some forms of leishmaniasis.

  18. 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].

  19. 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 produc...

  20. Shape rheocasting of high purity aluminium

    CSIR Research Space (South Africa)

    Curle, UA

    2011-03-01

    Full Text Available It is demonstrated experimentally that using the Council for Scientific and Industrial Research Rheo Casting System and high pressure die casting it is possible to semi-solid process and cast into a shape high purity aluminium without a...

  1. 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...

  2. 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...

  3. Aluminium overhead highway traffic sign structures

    NARCIS (Netherlands)

    Courage, W.M.G.; Soetens, F.; Noordzij, R.; Drabbels, J.

    1998-01-01

    This paper deals with the design and manufacturing of aluminium overhead sign structures. These gantries are built up by using two X-shaped column frames connected by a triangular space frame girder. Slenderness and a low solidity ratio were objectives in the architectonic design. Braces and main ch

  4. Aluminium building and civil engineering structures

    NARCIS (Netherlands)

    Soetens, F.; Mennink, J.

    1999-01-01

    The design of aluminium structures in building and civil engineering applications is different from designing in traditional materials. This difference is based on the physical and mechanical properties of the material and the freedom of cross-sectional shape provided by the extrusion manufacturing

  5. Steam generated conversion coating on aluminium alloys

    DEFF Research Database (Denmark)

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

    pressure steam produced by an autoclave at a temperature of 107 – 121 °C and pressure of 15 -17 psi for 10 minutes to produce a thin coating of aluminium oxide. The aim of this study is to understand the effect of high pressure steam with and without different chemical additives on surface morphology...

  6. Dissolved aluminium in the Southern Ocean

    NARCIS (Netherlands)

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

    2011-01-01

    Dissolved aluminium (Al) occurs in a wide range of concentrations in the world oceans. The concentrations of Al in the Southern Ocean are among the lowest ever observed. An all-titanium CTD sampling system makes it possible to study complete deep ocean sections of Al and other trace elements with th

  7. Impact toughness of laser surface alloyed Aluminium

    CSIR Research Space (South Africa)

    Mabhali, Luyolo AB

    2012-03-01

    Full Text Available Laser surface alloying of aluminium AA1200 was performed with a 4kW Nd:YAG laser and the impact resistance of the alloys was investigated. The alloying powders were a mixture of Ni, Ti and SiC in different proportions. Surfaces reinforced...

  8. Flexural buckling of fire exposed aluminium columns

    NARCIS (Netherlands)

    Maljaars, J.; Twilt, L.; Soetens, F.

    2009-01-01

    In order to study buckling of fire exposed aluminium columns, a finite element model is developed. The results of this model are verified with experiments. Based on a parametric study with the finite element model, it is concluded that the simple calculation model for flexural buckling of fire expos

  9. 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

  10. 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.

  11. Synthesis of N-decyl-1,3-diaminopropanes and its flotation properties on aluminium silicate minerals

    Institute of Scientific and Technical Information of China (English)

    胡岳华; 曹学锋; 李海普; 蒋玉仁; 杜平

    2003-01-01

    N-decyl-1, 3-diaminopropanes (DNs) were synthesized from alkyl-amine acrylonitrile at ambient pressure. With the synthesized DNs as collectors, the flotation of kaolinite, pyrophyllite and illite was conducted and the results were interpreted in terms of the structure-activity relationship. The DNs are found to be more effective collectors than dodecyl amine, exhibiting the highest recovery over a pH range of 4-6. Among the DNs examined, DN12 shows the highest flotation efficiency. The flotation mechanisms were explained in view of the structures of reagents and aluminium silicate minerals. It is demonstrated that DNs can become new selective collectors for reverse floatation to remove aluminium silicate minerals from bauxite.

  12. Aluminium in brain tissue in familial Alzheimer's disease.

    Science.gov (United States)

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

    2017-03-01

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

  13. Microemulsion extraction separation and determination of aluminium species by spectrofluorimetry.

    Science.gov (United States)

    Lu, Jusheng; Tian, Jiuying; Guo, Na; Wang, Yan; Pan, Yichun

    2011-01-30

    A simple and sensitive microemulsion extraction separation method was developed for the speciation of aluminium in tea samples by spectrofluorimetry. With 8-hydroxyquinoline (8-HQ) as the chelating agent and Triton X-100 Winsor II microemulsion as the extractant, separation of aluminium species in different pH solutions was achieved by microemulsion extraction. The formation of microemulsion, the conditions of extraction and determination of aluminium species were studied. The results showed that, the contents of aluminium species in tea leaves and infusions samples, such as total aluminium, total soluble aluminium, total granular aluminium, inorganic aluminium except Al-F, and (Al-F+Al-org), were obtained successfully under the optimal conditions. The limit of detection was 0.23 μg L(-1) in pH 9.5 solution, and 0.59 μg L(-1) in pH 6.0 solution respectively; the precision (RSD) for 11 replicate measurements of 10 μg L(-1) aluminium was 2.1% in pH 9.5 solution, and 2.8% in pH 6.0 solution respectively; the recoveries for the spiked samples were 96.8-103.5%. The proposed method is simple and efficient, which has been applied to the speciation of aluminium in tea samples with satisfactory results.

  14. Toxicity of dissolved and precipitated aluminium to marine diatoms.

    Science.gov (United States)

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

    2016-05-01

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

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

    Science.gov (United States)

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

    2016-04-20

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

  16. Evaluation of preservative effectiveness of p-coumaric acid derivatives in aluminium hydroxide gel-USP

    Directory of Open Access Journals (Sweden)

    Anurag Khatkar

    2013-01-01

    Full Text Available Background: Deterioration of pharmaceutical preparations due to growth of microorganisms is a great challenge and need of preservation becomes very important. Literature reports about various problems associated with the existing synthetic preservatives such as development of microbial resistance (in due course of time and several serious side effects. Aim: The aim of the present study is to find out new preservatives synthesized from natural sources, which may have better efficiency than the existing synthetic preservatives. The derivatives of naturally occurring p-coumaric acid were subjected for their preservative efficacy study. Their preservative efficiency was evaluated and compared with the standard parabens. Materials and Methods: The selected amide, anilide and ester derivatives of p-coumaric acid were subjected to preservative efficacy testing in an official antacid preparation, (aluminium hydroxide gel-USP against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Candida albicans and Aspergillus niger as representative challenging microorganisms as per USP 2004 guidelines. Results: The selected derivatives were found to be effective against all selected strains and showed preservative efficacy comparable to that of standard and even better in case E. coli, C. albicans and A. niger. The 8-hydroxy quinoline ester derivative showed better preservative efficacy than standard as well as other derivatives. Conclusion: The newly synthesized p- coumaric acid preservatives were found to be effective in the proposed pharmaceutical preparation (Aluminium Hydroxide Gel - USP. Also, the synthesized preservatives have shown comparative and even better efficacy than the existing parabens and hence they have potential for use in pharmaceutical preparations.

  17. Controlled information transmission of multi-dimensional quantum superdense coding%多维量子超密编码可控信息传输

    Institute of Scientific and Technical Information of China (English)

    蒋忠胜; 吕洪君; 解光军

    2013-01-01

    在量子信息传输过程中应减少作为量子信道的粒子数并尽量增加传输的信息,保证传输过程的安全和对传输信息过程进行有效控制.提出了一种多维量子编码的可控信息传输方案,首先Alice要和Bob对编码的信息制定一个规范,然后,Alice对粒子做幺正变换,接受者Bob对接收到的粒子进行测量,根据控制者Charlie发来的测量信息就可以知道Alice要传输的信息,这种量子信息传输粒子少,有一个控制者可对传输过程进行控制,所以易于实现,而且保证安全.%In the process of transferring quantum information,it is repuired to reduce the number of particles as the quantum channel and maximize the transmission of information,while the safety and control of the transmission procession must be ensured.A scheme of multi-dimensional quantum superdense coding controlled transmission of information was proposed.At first,Alice and Bob should make a standard for information that would be encoded,then Alice does unitary transformation to particles,Bob measures the received particles and obtains the information that Alice wants to transfer according to the information of Charlie sending.This kind of information transmission requires less transform particles,so it is easier to accomplish.There is a controller to control the transmission process for the safty.

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

    Science.gov (United States)

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

    2015-08-01

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

  19. 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?

  20. Boehmite nanostructures preparation by hydrothermal method from anodic aluminium oxide membrane.

    Science.gov (United States)

    Yang, X; Wang, J Y; Pan, H Y

    2009-02-01

    Boehmite nanostructures were successfully synthesized from porous anodic aluminium oxide (AAO) membrane by a simple and efficient hydro-thermal method. The experiment used high purity alumina as raw material, and the whole reaction process avoided superfluous impurities to be introduced. Thus, the purity of Boehmite products was ensured. The examinations of the morphology and structure were carried out by atomic force microscope (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Composition of the specimens was analyzed using energy dispersive X-ray spectroscope (EDX) and X-ray diffraction (XRD). Based on these observations the growth process was analyzed.

  1. The Friction of Saline Ice on Aluminium

    Directory of Open Access Journals (Sweden)

    Christopher Wallen-Russell

    2016-01-01

    Full Text Available The friction of ice on other materials controls loading on offshore structures and vessels in the Arctic. However, ice friction is complicated, because ice in nature exists near to its melting point. Frictional heating can cause local softening and perhaps melting and lubrication, thus affecting the friction and creating a feedback loop. Ice friction is therefore likely to depend on sliding speed and sliding history, as well as bulk temperature. The roughness of the sliding materials may also affect the friction. Here we present results of a series of laboratory experiments, sliding saline ice on aluminium, and controlling for roughness and temperature. We find that the friction of saline ice on aluminium μice-al=0.1 typically, but that this value varies with sliding conditions. We propose physical models which explain the variations in sliding friction.

  2. Nanoporous Aluminium Oxide Membranes as Cell Interfaces

    Directory of Open Access Journals (Sweden)

    Dorothea Brüggemann

    2013-01-01

    Full Text Available Nanoporous anodic aluminium oxide (AAO has become increasingly important in biomedical applications over the past years due to its biocompatibility, increased surface area, and the possibility to tailor this nanomaterial with a wide range of surface modifications. AAO nanopores are formed in an inexpensive anodisation process of pure aluminium, which results in the self-assembly of highly ordered, vertical nanochannels with well-controllable pore diameters, depths, and interpore distances. Because of these outstanding properties AAO nanopores have become excellent candidates as nanostructured substrates for cell-interface studies. In this comprehensive review previous surveys on cell adhesion and proliferation on different AAO nanopore geometries and surface modifications are highlighted and summarised tabularly. Future applications of nanoporous alumina membranes in biotechnology and medicine are also outlined, for instance, the use of nanoporous AAO as implant modifications, coculture substrates, or immunoisolation devices.

  3. Photoluminescence from Nd Doped Anodic Aluminium Oxide

    Institute of Scientific and Technical Information of China (English)

    ZHOU Zhang-Kai; PENG Xiao-Niu; SU Xiong-Rui; HAO Zhong-Hua

    2009-01-01

    We prepare Nd doped anodic aluminium oxide (Nd:AAO) template by using Nd doped aluminium foils through two-step anodization processes. Photoluminescence (PL) from the Nd:AAO template with the annealing temper-ature higher than 400℃ is observed, and the PL intensity enhanced with the increasing annealing temperature is found. We investigate the crystallization of Nd:AAO template and the excitation wavelength dependence of PL intensity, showing that the PL results from the Nd doped in the template. The approach presented may probably facilitate the fabricating of AAO with good light-emitting property, which can be used in fabrication of multifunctional nanosized films and may find applications in photonic devices.

  4. 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.

  5. The aluminium content of infant formulas remains too high.

    Science.gov (United States)

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

    2013-10-08

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

  6. 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

  7. Improvement of photodynamic activity of aluminium sulphophthalocyanine due to biotinylation

    Science.gov (United States)

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

    2003-09-01

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

  8. 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.)

  9. 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

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

    OpenAIRE

    2015-01-01

    This paper shows an influence of chemical composition of used electrolyte, such as amount of sulphuric acid in electrolyte, amount of aluminium cations in electrolyte and amount of oxalic acid in electrolyte, and operating parameters of process of anodic oxidation of aluminium such as the temperature of electrolyte, anodizing time, and voltage applied during anodizing process. The paper shows the influence of those parameters on the resulting thickness of aluminium oxide layer. The impact of...

  11. 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.

  12. Demethylation of Quinine Using Anhydrous Aluminium Trichloride

    OpenAIRE

    Aiyi Asnawi; As’ari Nawawi; Rahmana Emran Kartasasmita; Slamet Ibrahim3)

    2011-01-01

    Quinine is a natural alkaloid having a methoxy group bound to quinoline ring and an allyl group bound to quinuclidine ring. Demethylation of quinine applying strong acid such as HBr or HI at high temperature was unsuccessful. The aim of this research was to obtain demethylated quinine by means of mild and selective demethylation procedure to prevent the addition reaction of allyl group. Selective demethylation of quinine has been carried out using anhydrous aluminium trichloride as reagent. T...

  13. Welding distortion of aluminium structural members

    Energy Technology Data Exchange (ETDEWEB)

    Goglio, L. [Politecnico di Torino (Italy). Dept. of Mech.; Gugliotta, A. [Politecnico di Torino (Italy). Dept. of Mech.; Pasquino, D. [Politecnico di Torino (Italy). Dept. of Mech.

    1996-12-31

    The paper deals with the angular distortion induced in aluminium tubular beams during welding to prepare T junctions. The research, based on experimental measurements, makes use of statistical methods to identify the parameters (beam section, weld length, welding direction, etc.) that influence the angular change. The results are discussed also considering a model known from the literature. It is found that the distortion is generally low and can be minimized by a proper welding process. (orig.)

  14. 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.

  15. Telangiectasia in aluminium workers: a follow up.

    OpenAIRE

    Thériault, G.; Gingras, S.; Provencher, S

    1984-01-01

    A five step investigation was carried out to gain a better understanding of the morbidity that accompanied the development of telangiectasia on aluminium workers and to find its cause. Fifty workers with multiple telangiectasia when matched with normal controls showed the same amount of illness except that evidence of ischaemia on the ECG was found in nine cases and one control. The cases did not show an excess of abnormal biochemical tests. The basic histopathological lesion affected the sur...

  16. 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.

  17. Structural engineering of nanoporous anodic aluminium oxide by pulse anodization of aluminium.

    Science.gov (United States)

    Lee, Woo; Schwirn, Kathrin; Steinhart, Martin; Pippel, Eckhard; Scholz, Roland; Gösele, Ulrich

    2008-04-01

    Nanoporous anodic aluminium oxide has traditionally been made in one of two ways: mild anodization or hard anodization. The first method produces self-ordered pore structures, but it is slow and only works for a narrow range of processing conditions; the second method, which is widely used in the aluminium industry, is faster, but it produces films with disordered pore structures. Here we report a novel approach termed "pulse anodization" that combines the advantages of the mild and hard anodization processes. By designing the pulse sequences it is possible to control both the composition and pore structure of the anodic aluminium oxide films while maintaining high throughput. We use pulse anodization to delaminate a single as-prepared anodic film into a stack of well-defined nanoporous alumina membrane sheets, and also to fabricate novel three-dimensional nanostructures.

  18. A Reaction Coating on Aluminium Alloys by Laser Processing

    OpenAIRE

    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 the metal/oxide wetting and the formation of Al2O3 layer. This new approach of ceramic coating on metals using a chemical reaction of other ceramics with metals may be applied to other systems.

  19. 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.

  20. 非对称量子通道密集编码的安全直接通讯%Quantum Direct Communication with Non-symmetric Quantum Channel Superdense Coding

    Institute of Scientific and Technical Information of China (English)

    樊秋波; 郑贞今

    2007-01-01

    提出了一个利用非对称密集编码的直接通讯方案.在这个方案中,服务器把初始状态制备在两组正交基上,这样就可以防止其他人完美地复制这些量子态,提高方案的安全性.而且本方案是基于密集编码之上,大大提高了信息量的传输率.%A scheme of quantum direct communication using non-symmetric quantum channel superdense coding is proposed.In this scheme,the server prepares the initial states in two nonorthogonal basis sets which forbids any one to copy them perfectly,so the scheme is more secure.This scheme also has a higher capacity than other schemes,for using the ideas in non-symmetric quantum channel superdense coding.

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

    DEFF Research Database (Denmark)

    Lai, Xuxin; Zheng, Yiwu; Søndergaard, Ib

    2007-01-01

    A method for determining the aluminium content of an aluminium hydroxide suspension using near infrared (NIR) transmittance spectroscopy has been developed. Inductively coupled plasma-atomic emission spectroscopy (ICP-AES) was used as reference method. The factors influencing the NIR analysis......-AES and NIR transmittance spectroscopy exhibit comparable precision and accuracy. The NIR method provides several advantages: no complicated sample preparation; easy to operate; fast and non-destructive. In conclusion, NIR transmittance spectroscopy can be an alternative analytical method for determining...

  2. Long-term effects of aluminium dust inhalation.

    Science.gov (United States)

    Peters, Susan; Reid, Alison; Fritschi, Lin; de Klerk, Nicholas; Musk, A W Bill

    2013-12-01

    During the 1950s and 1960s, aluminium dust inhalation was used as a potential prophylaxis against silicosis in underground miners, including in Australia. We investigated the association between aluminium dust inhalation and cardiovascular, cerebrovascular and Alzheimer's diseases in a cohort of Australian male underground gold miners. We additionally looked at pneumoconiosis mortality to estimate the effect of the aluminium therapy. SMRs and 95% CI were calculated to compare mortality of the cohort members with that of the Western Australian male population (1961-2009). Internal comparisons on duration of aluminium dust inhalation were examined using Cox regression. Aluminium dust inhalation was reported for 647 out of 1894 underground gold miners. During 42 780 person-years of follow-up, 1577 deaths were observed. An indication of increased mortality of Alzheimer's disease among miners ever exposed to aluminium dust was found (SMR=1.38), although it was not statistically significant (95% CI 0.69 to 2.75). Rates for cardiovascular and cerebrovascular death were above population levels, but were similar for subjects with or without a history of aluminium dust inhalation. HRs suggested an increasing risk of cardiovascular disease with duration of aluminium dust inhalation (HR=1.02, 95% CI 1.00 to 1.04, per year of exposure). No difference in the association between duration of work underground and pneumoconiosis was observed between the groups with or without aluminium dust exposure. No protective effect against silicosis was observed from aluminium dust inhalation. Conversely, exposure to aluminium dust may possibly increase the risk of cardiovascular disease and dementia of the Alzheimer's type.

  3. There is (still) too much aluminium in infant formulas

    Science.gov (United States)

    2010-01-01

    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. PMID:20807425

  4. 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.

  5. 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.)

  6. Preparation of polymeric aluminium ferric chloride from bauxite tailings

    Directory of Open Access Journals (Sweden)

    Ma D.

    2013-01-01

    Full Text Available Bauxite tailings are the main solid wastes in the ore dressing process. The Al2O3 and Fe2O3 contents in bauxite tailings can reach 50% and 13% respectively. The present study proposed a feasible method to use bauxite tailings to prepare polymeric aluminium ferric chloride (PAFC, a new composite inorganic polymer for water purification. Bauxite tailings roasted reacting with hydrochloric acid under air, pickle liquor which mainly contains Fe3+, Al3+ was generated, then calcium aluminate was used to adjust pH value and the basicity of the pickle liquor, the PAFC was subsequently prepared after the polymerization process. The optimal synthesizing parameters for the preparation of PAFC obtained were as follows: the concentration of hydrochloric acid of 24 wt%, ratio of hydrochloric acid to bauxite tailings of 6:1, temperature of 90ºC, leaching time of 2.5 hours, ration of pickle liquor to calcium aluminate of 12:1, polymerization temperature of 90ºC and polymerization time of about 3 hours. The basicity of PAFC was higher than 68%, the sum concentration of Al2O3 and Fe2O3 was beyond 12.5%. The results of flocculation tests indicate that the PAFC has a better performance of removing the turbidity of wastewater compared to PAC, and PAFC prepared by bauxite tailings is a kind of high quality flocculants.

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

    Science.gov (United States)

    Frankowski, Marcin; Zioła-Frankowska, Anetta

    2010-10-15

    The study presents a new analytical method for speciation analysis in fractionation of aluminium fluoride complexes and free Al(3+) in soil samples. Aluminium speciation was studied in model solutions and soil extract samples by means of high performance ion chromatography (HPIC) with UV-VIS detection using post-column reaction with tiron for the separation and detection of aluminium fluoride complex and Al(3+) forms during one analysis. The paper presents particular stages of the chromatographic process optimization involving selecting the appropriate eluent strength, type of elution or concentration and quantity of derivatization reagent. HPIC was performed on a bifunctional analytical column Dionex IonPac CS5A. The use of gradient elution and the eluents A: 1M NH(4)Cl and B: water acidified to pH of eluent phase, enabled full separation of fluoride aluminium forms as AlF(2)(+), AlF(3)(0), AlF(4)(-) (first signal), AlF(2+) (second signal) and form Al(3+) in a single analytical procedure. The proposed new method HPIC-UVVIS was applied successfully in the quantitative and qualitative analysis of soil samples. Copyright © 2010 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

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

    2007-09-01

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

  9. 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

  10. 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

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

    Science.gov (United States)

    Tsakiridis, P E

    2012-05-30

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

  13. 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

  14. 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.

  15. 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

  16. 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

  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. Finite size melting of spherical solid-liquid aluminium interfaces

    DEFF Research Database (Denmark)

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

    2009-01-01

    We have investigated the melting of nano-sized cone shaped aluminium needles coated with amorphous carbon using transmission electron microscopy. The interface between solid and liquid aluminium was found to have spherical topology. For needles with fixed apex angle, the depressed melting...

  19. 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

  20. Aluminium/iron reinforced polyfurfuryl alcohol resin as advanced biocomposites

    Directory of Open Access Journals (Sweden)

    Rakesh Kumar

    2016-07-01

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

  1. Durability of Lacquered Aluminium Profile Considering Tropical Weather Conditions

    Directory of Open Access Journals (Sweden)

    Rigoberto Marrero Águila

    2013-11-01

    Full Text Available Searching for solutions against the degradation of materials by corrosion effect, is a common practice to use alloys such as aluminium instead of steel due to the advantages obtained. The lacquered aluminium profiles can substitute other materials like wood, in the carpentry production, becoming an economic saving. There is an increasingly use of aluminium replacing other traditional materials in the constructions in process, but its quality has been reduced in a considerable amount of installations. In this research, aluminium profiles from five different sources were submitted to a trial in natural exposition conditions at the Tropical weather condition Testing Lab, in order to evaluate their behaviour and establish, for the first time in our country, standing rules for lacquered aluminium profiles to be strictly fulfilled by manufacturers and importers. The results will allow modifying thickness standards of this type of coating, to guaranty its durability and to eliminate the failures provoked by our high severe weather conditions.

  2. Experimental investigations on mechanical behavior of aluminium metal matrix composites

    Science.gov (United States)

    Rajesh, A. M.; Kaleemulla, Mohammed

    2016-09-01

    Today we are widely using aluminium based metal matrix composite for structural, aerospace, marine and automobile applications for its light weight, high strength and low production cost. The purpose of designing metal matrix composite is to add the desirable attributes of metals and ceramics to the base metal. In this study we developed aluminium metal matrix hybrid composite by reinforced Aluminium7075 alloy with silicon carbide (SiC) and aluminium oxide (alumina) by method of stir casting. This technique is less expensive and very effective. The Hardness test and Wear test were performed on the specimens which are prepared by stir casting techniques. The result reveals that the addition of silicon carbide and alumina particles in aluminium matrix improves the mechanical properties.

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

    Science.gov (United States)

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

    2015-01-01

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

  4. 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.

  5. Characterization and Empirical Modelling of Sliding Wear on Sintered Aluminium-Graphite Composites

    Directory of Open Access Journals (Sweden)

    Amrishraj Doraisamy

    2014-01-01

    Full Text Available Aluminium-graphite composites were synthesized using powder metallurgy route. Graphite was added as reinforcement in the range of 0, 3, and 6 weight % and composites were prepared by P/M. Microstructural analysis of the newly synthesized composites was carried out using SEM. The hardness of the composites was studied using Vickers microhardness tester, by applying a load of 1 kg for 5 sec. Also the amount of porosity was determined. Further the wear test was conducted on the sintered specimens using pin-on-disc wear apparatus according to ASTM-G99 standards. A regression model was developed to predict the wear rate of the specimen. Then the worn images were studied using SEM based on response surface methodology in order to understand the various wear mechanisms involved. The study revealed that mild wear, oxidational wear, plowing, cutting, and plastic deformation are the main mechanisms responsible for causing the wear.

  6. 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

  7. 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.

  8. Experimental fatigue curves for aluminium brazed areas

    Science.gov (United States)

    Dimitescu, A.; Babiş, C.; Niţoi, D. F.; Radu, C.

    2017-08-01

    An important factor for the quality of joints is the brazed area. The fatigue check occupies a major position among many test procedures and methods, especially by the joining technologies. The results of processing the fatigue data experiments for aluminium brazed samples are used to find the regression function and the response surface methodology. The fatigue process of mechanical components under service loading is stochastic in nature. The prediction of time-dependent fatigue reliability is critical for the design and maintenance planning of many structural components.

  9. Forming of aluminium alloy friction stir welds

    Science.gov (United States)

    Bruni, Carlo

    2016-10-01

    The present paper aims at investigating, through analytical models, numerical models and experiments, the effect of the warm deformation phase, realised with an in temperature upsetting, on the weld previously performed by friction stir lap welding on aluminium alloy blanks. The investigation allows to show the deformation zones after upsetting that determine the homogenisation of the weld section. The analytical model allows to relate the friction factor with the upsetting load. The presence on the weld of not elevated friction factor values determines the deformation and localisation levels very useful for the weld. Such methodology allows to improve the weld itself with the forming phase.

  10. Deviatoric response of the aluminium alloy, 5083

    Science.gov (United States)

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

    2009-06-01

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

  11. 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. Green syntheses, v.1

    CERN Document Server

    Tundo, Pietro

    2014-01-01

    Introduction to the Green Syntheses SeriesPietro Tundo and John AndraosApplication of Material Efficiency Metrics to Assess Reaction Greenness-Illustrative Case Studies from Organic SynthesesJohn AndraosReaction 1: Synthesis of 3-Benzyl-5-Methyleneoxazolidin-2-one from N-Benzylprop-2-yn-1-Amine and CO2Qing-Wen Song and Liang-Nian HeReaction 2: Synthesis of the 5-Membered Cyclic Carbonates from Epoxides and CO2Qing-Wen Song, Liang-Nian HePart I: Green Methods for the Epoxidation of

  13. Quantum Superdense Coding Scheme Based on High-dimensional Two-particles System%基于高维两粒子纠缠态的超密编码方案

    Institute of Scientific and Technical Information of China (English)

    黄平武; 周萍; 农亮勤; 何良明; 尹彩流

    2011-01-01

    基于通信双方预先共享d维二粒子最大纠缠态非定域相关性,信息发送方Bob只需要向信息接收者Alice传送一个粒子,就可以传送log22比特经典信息,为保护信息的安全,方案采用诱骗光子技术,安全性等价于改进后的原始量子密钥分配方案(Bennett-Brassard 1984,BB84).本文讨论了基于高维纯纠缠态超密编码方案.即通过引入一个附加量子比特,信息接收方对手中的纠缠粒子和附加粒子在执行相应的幺正演化,可以获取d|ak|2 logd2 +logd2(ak=min{aj},j ∈ {O,L,d-1})比特经典信息.通信双方采用诱骗光子技术确保量子信道的安全建立.与其他方案相比,该方案具有通信效率较高、实用性较强的优点.%The author presents a generalized superdense coding scheme based on high-dimensional two particles maximally entangled state following some ideas of superdense coding scheme based on fourdimensional two particles. The quantum superdense coding based on noisy quantum channel was discussed. The receiver(Alice)can extract d|αk|2 logdj2 + log2d (αk = min {α}, j ∈ {0,L,d-1 } ) bits classic information by introducing one auxiliary two-level particle and perfprming corresponding unitray operation on her particles. All the parties can use some decoy photons to set up their quantum channel securely. The scheme only requires pure entangled state, which makes this scheme more convenient than others in practical application. Moreover, it has the advantage of having high communication efficiency.

  14. 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.

  15. 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.

  16. Synthesized night vision goggle

    Science.gov (United States)

    Zhou, Haixian

    2000-06-01

    A Synthesized Night Vision Goggle that will be described int his paper is a new type of night vision goggle with multiple functions. It consists of three parts: main observing system, picture--superimposed system (or Cathode Ray Tube system) and Charge-Coupled Device system.

  17. Does allergen-specific immunotherapy induce contact allergy to aluminium?

    Science.gov (United States)

    Netterlid, Eva; Hindsén, Monica; Siemund, Ingrid; Björk, Jonas; Werner, Sonja; Jacobsson, Helene; Güner, Nuray; Bruze, Magnus

    2013-01-01

    Persistent, itching nodules have been reported to appear at the injection site after allergen-specific immuno-therapy with aluminium-precipitated antigen extract, occasionally in conjunction with contact allergy to aluminium. This study aimed to quantify the development of contact allergy to aluminium during allergen-specific immunotherapy. A randomized, controlled, single-blind multicentre study of children and adults entering allergen-specific immunotherapy was performed using questionnaires and patch-testing. A total of 205 individuals completed the study. In the 3 study groups all subjects tested negative to aluminium before allergen-specific immunotherapy and 4 tested positive after therapy. In the control group 4 participants tested positive to aluminium. Six out of 8 who tested positive also had atopic dermatitis. Positive test results were found in 5/78 children and 3/127 adults. Allergen-specific immunotherapy was not shown to be a risk factor for contact allergy to aluminium. Among those who did develop aluminium allergy, children and those with atopic dermatitis were more highly represented.

  18. Study of ac electrical properties of aluminium-epoxy composites

    Energy Technology Data Exchange (ETDEWEB)

    Elimat, Z M [Applied Science Department, Ajloun University College, Al-Balqa Applied University, Amman (Jordan); Zihlif, A M [Physics Department, University of Jordan, Amman (Jordan); Ragosta, G [Institute of Chemistry and Polymer Technology (ICTP), CNR-Possouli, Napoli (Italy)], E-mail: adzh@ju.edu.jo

    2008-08-21

    Ac electrical properties of aluminium flakes-epoxy composites were studied as a function of the composition, frequency and temperature. The dielectric constant increased smoothly with an increase in the concentration of aluminium. An increase in the dielectric constant was observed with the temperature as well as with a decrease in the frequency. The observed increase in the values of the dielectric constant with the aluminium concentration was attributed to interfacial polarization. It was found that ac electrical conductivity increases with increasing content of aluminium, temperature and frequency. The observed enhancement in ac conductivity is attributed to the increase in the number of conduction paths created by the aluminium flake contacts in the composite to give a higher electrical conductivity. Also, the activation energy of aluminium flakes-epoxy composites was determined, as well as the values of the dielectric constant. Compared with various theoretical models, Bruggman's formula gives a better fit. The universal power-law model of ac conductivity is observed in epoxy-aluminium composites. The calculated power exponent (about unity) is physically acceptable within this applied model.

  19. Mechanical and durability aspects of concrete incorporating secondary aluminium slag

    Directory of Open Access Journals (Sweden)

    M. Satish Reddy

    2016-12-01

    Full Text Available The environmental impact can be minimised by making use of many industrial wastes in a sustainable manner. Recycling and reutilisation of industrial waste and by-products is of paramount importance in cement and concrete industry. In view of rapid infrastructure growth, there is an emerging need for development of cementitious materials or fillers either to replace cement or fine aggregate for stable growth. One of the industrial wastes is secondary aluminium dross. In this paper, an attempt has been made to study the mechanical and durability aspects of concrete incorporated with secondary aluminium dross. Cement has been partially replaced by secondary aluminium dross in different proportions to study the mechanical and durability aspects. Various properties such as compressive strength, split tensile strength, flexural strength, sorptivity, water absorption, rapid chloride penetration have been studied for the usefulness of secondary aluminium dross as construction material. It is observed that up to 15% replacement of cement by secondary aluminium dross, the responses are comparable with the conventional concrete. Studies have also been carried out by adding other supplementary cementitious materials such as fly ash and silica fume in various proportions along with secondary aluminium dross and found the improved mechanical and durability properties. From the overall study, it can be concluded that the concrete incorporated with secondary aluminium dross can be used for making paver blocks, refractory bricks and for normal concrete strength applications.

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

    Science.gov (United States)

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

    2016-06-15

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

  1. Cold forming of aluminium - State of the art

    DEFF Research Database (Denmark)

    Bay, Niels

    1997-01-01

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

  2. 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...

  3. 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.

  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. 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.

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

    DEFF Research Database (Denmark)

    Rahimi, Maral; Fojan, Peter; Gurevich, Leonid;

    2014-01-01

    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...

  7. 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.

  8. 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.

  9. Silane based coating of aluminium mold

    DEFF Research Database (Denmark)

    2013-01-01

    comprising a chemically bonded monolayer of silane compounds on the at least one surface wherein the silane is a halogenated silane. The at least one surface coated with the anti-stiction coating may be configured to withstand an injection molding process at a pressure above 100 MPa. Furthermore, a mold......A method of preparing an aluminum mold for injection molding is provided, the method comprises the steps of providing an aluminum mold having a least one surface, subjecting the at least one surface to a gas or liquid phase silane to thereby form an anti-stiction coating, the anti-stiction coating...... 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...

  10. 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.

  11. Protection of aluminium by duplex coatings

    Energy Technology Data Exchange (ETDEWEB)

    Musil, J. [Ceska Akademie Ved, Prague (Czech Republic). Fyzikalni Ustav; Vlcek, J. [West Bohemia Univ., Plzen (Czech Republic). Dept. of Phys.; Jezek, V. [West Bohemia Univ., Plzen (Czech Republic). Dept. of Phys.; Benda, M. [West Bohemia Univ., Plzen (Czech Republic). Dept. of Phys.

    1995-11-01

    The paper reports on a new way of producing duplex coatings consisting of two steps. First, the substrate is coated by a physically vapour-deposited coating. Then, this precoated substrate is plasma nitrided or vacuum heat treated. This method was tested in the protection of substrates made of aluminium with a sputtered Ti coating about 5 {mu}m thick. The as-deposited and then plasma-nitrided or vacuum-heat-treated (Ti coating)/(Al substrate) couple was characterized by elemental depth profiles measured by glow discharge optical spectroscopy. It was shown that both the plasma nitriding and vacuum heat treatment process can stimulate a strong interdiffusion between Ti and the substrate elements. It results not only in the formation of a very broad interfacial region with a dramatic redistribution of the substrate elements in the Ti film but also in a formation of intermetallic Ti-Al compounds. This new duplex coating technique is described in detail. (orig.)

  12. Telangiectasia in aluminium workers: a follow up.

    Science.gov (United States)

    Thériault, G; Gingras, S; Provencher, S

    1984-08-01

    A five step investigation was carried out to gain a better understanding of the morbidity that accompanied the development of telangiectasia on aluminium workers and to find its cause. Fifty workers with multiple telangiectasia when matched with normal controls showed the same amount of illness except that evidence of ischaemia on the ECG was found in nine cases and one control. The cases did not show an excess of abnormal biochemical tests. The basic histopathological lesion affected the surrounding tissue rather than the vessels themselves. Working in the current environment and wearing masks seems to protect young workers from developing the lesions. The Soderberg and not the prebake process was associated with the lesions; the causative agent is probably a gas that contains both hydrocarbons and fluoride components emitted from the electrolytic reactors.

  13. Incremental forming of aluminium alloys in cryogenic environment

    Science.gov (United States)

    Vanhove, Hans; Mohammadi, Amirahmad; Duflou, Joost R.

    2016-10-01

    Incremental Sheet Forming processes suffer from stringent forming limits, restricting the range of producible geometries. Through in-process cooling of the sheet to cryogenic level, this paper explores the potential of altering material properties benefiting the formability and residual hardness of different aluminium alloys. Global cooling of aluminium sheets with liquid nitrogen and dry ice allows to reach temperatures of 78K and 193K respectively. Extended with experiments at room temperature (293K), these tests form a base for comparison of surface quality, formability and residual hardness. As an aluminium alloy commonly used for its high strength to weight ratio, but suffering from limited formability compared to draw-quality steels, AA5083-H111 is of interest for cryogenic treatment. AA1050-H24 is included in the test campaign as a base for commercially pure aluminium.

  14. 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.

  15. Combining drought and aluminium toxicity tolerance to improve ...

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    Combining drought and aluminium toxicity to improve sorghum. 149 effects of ..... ability to withstand toxic Al3+ concentration. (Table 2). .... Kenyan maize germplasm for tolerance to low soil ... and lodging resistance for a quality sorghum crop.

  16. Anodic aluminium oxide catalytic membranes for asymmetric epoxidation.

    Science.gov (United States)

    Cho, So-Hye; Walther, Nolan D; Nguyen, SonBinh T; Hupp, Joseph T

    2005-11-14

    Catechol-functionalized (salen)Mn complexes can be supported on mesoporous anodized aluminium oxide disks to yield catalytic membranes that are highly active in the enantioselective epoxidation of olefins when being deployed in a forced-through-flow reactor.

  17. 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.

  18. 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.)

  19. Synthesis and characterization of ZSM-12 type zeolytic catalysts by using different aluminium sources in the petroleum industry; Sintese e caracterizacao de catalisadores zeoliticos do tipo ZSM-12 utilizando diferentes fontes de aluminio na industria do petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, Marilia R.F.S.; Jesus, Daniela B.; Souza, Marcelo J.B. [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil). Dept. de Engenharia Quimica; Santos, Consuelo D.; Machado, Sanny W.M.; Pedrosa, Anne M. Garrido [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil). Dept. de Quimica

    2010-12-15

    The main objective was to synthesize and characterize ZSM-12 zeolites from different sources of aluminium, using hydrothermal method and characterize the catalysts synthesized by X-ray diffractions, thermal analysis and infrared absorption spectroscopy. The X-ray diffractogram showed the formation of zeolites of the family pantasil crystalline. Thermogravimetric curves and FTIR spectra were utilized by monitoring the removal of template and by monitoring the maintenance of zeolite structure. (author)

  20. 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.

  1. 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.

  2. 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

  3. Behaviour and modelling of selfpiercing riveted connections using aluminium rivets

    OpenAIRE

    Hoang, Nguyen-Hieu

    2011-01-01

    The present thesis is concerned with the behaviour and modelling of self-piercing riveted connections using aluminium rivets. The objective has been to establish a database on the behaviour of self-piercing riveted connections using aluminium rivets with respect to the riveting process, the mechanical behaviour of single riveted connections and the structural behaviour of riveted joints. The objective has been met by a combination of laboratory tests, modelling and non-linear finite element n...

  4. 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...

  5. Metastable Al-Sc phase diagram in aluminium rich region

    Energy Technology Data Exchange (ETDEWEB)

    Drits, M.E.; Toropova, L.S.; Bykov, Yu.G.; Gushchina, F.L.; Elagin, V.I.; Filatov, Yu.A.

    1982-12-01

    An aluminium rich part of binary metastable phase diagram Al-Sc for 100 deg/s alloy cooling rate under crystallization is studied. Eutectic horizontal in the metastable diagram is 4 deg lower as compared to the equilibrium one, scandium concentration in the eutectic point makes up approximately 0.8%, the maximum solubility is 0.6%. Maximum cast grain refining in aluminium under crystallization at the rate of 100 deg/s is attained at 0.6% scandium content.

  6. An interaction of beta-amyloid with aluminium in vitro.

    Science.gov (United States)

    Exley, C; Price, N C; Kelly, S M; Birchall, J D

    1993-06-21

    We have used circular dichroism spectroscopy to confirm that, in a membrane-mimicking solvent, A beta P(1-40) adopts a partially helical conformation and we have demonstrated the loss of this structure in the presence of physiologically relevant concentrations of aluminium. This is the first evidence of a direct biochemical interaction between aluminium and beta-amyloid and may have important implications for the pathogenesis of Alzheimer's disease.

  7. 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...

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

    Science.gov (United States)

    Exley, Christopher; Mold, Matthew J

    2015-04-01

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

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

    Science.gov (United States)

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

    2012-12-01

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

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

    Science.gov (United States)

    Bose, Jayakumar; Babourina, Olga; Rengel, Zed

    2011-04-01

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

  11. A mechanism for acute aluminium toxicity in fish.

    Science.gov (United States)

    Exley, C; Chappell, J S; Birchall, J D

    1991-08-07

    Aluminium is acutely toxic to fish in acid waters. The gill is the principal target organ and death is due to a combination of ionoregulatory, osmoregulatory and respiratory dysfunction. The toxic mechanism has hitherto received little direct consideration and is unknown. In this paper the mechanism of acute aluminium toxicity is approached from a chemical perspective. Symptomatic evidence of toxicity is taken from the literature and combined with our own research to elucidate a biochemically sound model to describe a possible mechanism of acute aluminium toxicity in fish. The proposed model delineates the chemical conditions immediately adjacent to the gill surface and emphasizes their importance in aluminium's toxic mode of action. The mechanism is shown to be bipartite. Aluminium binding to functional groups both apically located at the gill surface and intracellularly located within lamellar epithelial cells disrupts the barrier properties of the gill epithelium. The concomitant iono- and osmoregulatory dysfunction results in accelerated cell necrosis, sloughing and death of the fish. The mechanism of epithelial cell death is proposed as a general mechanism of aluminium-induced accelerated cell death.

  12. 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.

  13. The green alga Zygogonium ericetorum (Zygnematophyceae, Charophyta) shows high iron and aluminium tolerance: protection mechanisms and photosynthetic performance.

    Science.gov (United States)

    Herburger, Klaus; Remias, Daniel; Holzinger, Andreas

    2016-08-01

    Streptophyte green algae, ancestors of Embryophytes, occur frequently in terrestrial habitats being exposed to high light intensities, water scarcity and potentially toxic metal cations under acidic conditions. The filamentous Zygogonium ericetorum synthesizes a purple vacuolar ferrous pigment, which is lost after aplanospore formation. However, it is unknown whether this cellular reorganization also removes excessive iron from the protoplast and how Z. ericetorum copes with high concentrations of aluminium. Here we show that aplanospore formation shifts iron into the extracellular space of the algal filament. Upon germination of aplanospores, aluminium is bound in the parental cell wall. Both processes reduce iron and aluminium in unpigmented filaments. Comparison of the photosynthetic oxygen production in response to light and temperature gradients in two different Z. ericetorum strains from an Austrian alpine and a Scottish highland habitat revealed lower values in the latter strain. In contrast, the Scottish strain showed a higher optimum quantum yield of PSII during desiccation stress followed by rehydration. Furthermore, pigmented filaments of both strains exhibited a higher light and temperature dependent oxygen production when compared to the unpigmented phenotype. Our results demonstrate a high metal tolerance of Z. ericetorum, which is crucial for surviving in acidic terrestrial habitats. © FEMS 2016.

  14. Nanocomposite TiC/a-C:H film prepared on titanium aluminium alloy substrates by PSII assistant MW-ECRCVD

    Institute of Scientific and Technical Information of China (English)

    Ma Guo-Jia; Liu Xi-Liang; Zhang Hua-Fang; Wu Hong-Chen; Peng Li-Ping

    2007-01-01

    Thin films of titanium carbide and amorphous hydrogenated carbon have been synthesized on titanium aluminium alloy substrates by PSII assisted MW-ECRCVD with a mirror field. The microstructure, chemical composition and nanometre grains (namely, the so-called nanocomposite structure). The size of TiC grains of nanocomposite TiC/DLC film is about 5 nm. The nanocomposite structure has obvious improvement in the mechanical properties of DLC film.the coherent strength is also obviously enhanced at the critical load of about 35N.

  15. 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.

  16. Method for synthesizing HMX

    Science.gov (United States)

    McGuire, Raymond R.; Coon, Clifford L.; Harrar, Jackson E.; Pearson, Richard K.

    1984-01-01

    A method and apparatus for electrochemically synthesizing N.sub.2 O.sub.5 cludes oxidizing a solution of N.sub.2 O.sub.4 /HNO.sub.3 at an anode, while maintaining a controlled potential between the N.sub.2 O.sub.4 /HNO.sub.3 solution and the anode. A potential of about 1.35 to 2.0 V vs. SCE is preferred, while a potential of about 1.80 V vs. SCE is most preferred. Thereafter, the N.sub.2 O.sub.5 is reacted with either 1.5-diacetyl-3,7-dinitro-1,3,5,7-tetraazacyclooctane (DADN) or 1,3,5,7-tetraacetyl-1,3,5,7-tetraazacyclooctane (TAT) to form cyclotetramethylenetetraamine (HMX).

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

    Science.gov (United States)

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

    2011-10-01

    The accumulation and toxicity of aluminium in freshwater organisms have primarily been examined following aqueous exposure. This study investigated the uptake, excretion and toxicity of aluminium when presented as aluminium-contaminated food. Adult Pacifastacus leniusculus were fed control (3 μg aluminium/g) or aluminium-spiked pellets (420 μg aluminium/g) over 28 days. Half the crayfish in each group were then killed and the remainder fed control pellets for a further 10 days (clearance period). Concentrations of aluminium plus the essential metals calcium, copper, potassium and sodium were measured in the gill, hepatopancreas, flexor muscle, antennal gland (kidney) and haemolymph. Histopathological analysis of tissue damage and sub-cellular distribution of aluminium were examined in the hepatopancreas. Haemocyte number and protein concentration in the haemolymph were analysed as indicators of toxicity. The hepatopancreas of aluminium-fed crayfish contained significantly more aluminium than controls on days 28 and 38, and this amount was positively correlated with the amount ingested. More than 50% of the aluminium in the hepatopancreas of aluminium-fed crayfish was located in sub-cellular fractions thought to be involved in metal detoxification. Aluminium concentrations were also high in the antennal glands of aluminium-fed crayfish suggesting that some of the aluminium lost from the hepatopancreas is excreted. Aluminium exposure via contaminated food caused inflammation in the hepatopancreas but did not affect the number of circulating haemocytes, haemolymph ion concentrations or protein levels. In conclusion, crayfish accumulate, store and excrete aluminium from contaminated food with only localised toxicity. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Mesoporous aluminium organophosphonates: a reusable chemsensor for the detection of explosives

    Science.gov (United States)

    Li, Dongdong; Yu, Xiang

    2016-07-01

    Rapid and sensitive detection of explosives is in high demand for homeland security and public safety. In this work, electron-rich of anthracene functionalized mesoporous aluminium organophosphonates (En-AlPs) were synthesized by a one-pot condensation process. The mesoporous structure and strong blue emission of En-AlPs were confirmed by the N2 adsorption-desorption isotherms, transmission electron microscopy images and fluorescence spectra. The materials En-AlPs can serve as sensitive chemosensors for various electron deficient nitroderivatives, with the quenching constant and the detection limit up to 1.5×106 M-1 and 0.3 ppm in water solution. More importantly, the materials can be recycled for many times by simply washed with ethanol, showing potential applications in explosives detection.

  19. Synthesis and Characterization of TiB2 Reinforced Aluminium Matrix Composites: A Review

    Science.gov (United States)

    Kumar, Narendra; Gautam, Gaurav; Gautam, Rakesh Kumar; Mohan, Anita; Mohan, Sunil

    2016-10-01

    Aluminium-matrix composites (AMCs) are developed to meet the demands of light weight high performance materials in aerospace, automotive, marine and other applications. The properties of AMCs can be tailored suitably by combinations of matrix, reinforcement and processing route. AMCs are one of the most attractive alternatives for the manufacturing of light weight and high strength parts due to their low density and high specific strength. There are various techniques for preparing the AMCs with different reinforcement particles. In AMCs, the reinforcements are usually in the form of metal oxides, carbides, borides, nitrides and their combination. Among the various reinforcements titanium di-boride (TiB2) is of much interest due to its excellent stiffness, hardness, and wear resistance. This paper attempts to provide an overview to explore the possibilities of synthesizing titanium di-boride reinforced AMCs with different techniques. The mechanical and tribological properties of these composites have been emphasized to project these as tribo-materials.

  20. 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.

  1. 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.

  2. Neurocognitive effects in welders exposed to aluminium.

    Science.gov (United States)

    Giorgianni, Concetto Mario; D'Arrigo, Graziella; Brecciaroli, Renato; Abbate, Adriana; Spatari, Giovanna; Tringali, Maria Antonietta; Gangemi, Silvia; De Luca, Annamaria

    2014-05-01

    Various authors who studied the effects of aluminium (Al) exposure on the neurocognitive system in the last 30 years have reached different and often contradictory conclusions. The aim of this study is to help clarify the effects that the metal causes on cognitive ability in a group of naval welders exposed to Al. The study was performed on a sample of 86 male Al welders in a shipyard in Messina. The average value of environmental Al, recorded in the workplace, was 19.5 mg/m(3). The blood levels of Al, zinc, manganese, lead and chromium were monitored in all the subjects. The reagents used for the neuropsychic study were the Wechsler Memory Scale (WMS), the Colour Word Test or Stroop Test and the Test of Attention Matrixes. The results were compared with those obtained in a similar control group not exposed to Al and with an Al-b value of 6.93 g/l. For all the mental reagents used, the reply is obtained in the sample of exposed subjects showed decreased cognitive response with regard to attention and memory performance. The comparison between the individual tests showed greater sensitivity of performance studied using the WMS and the Stroop Test compared with the Test of Attention Matrixes. The alterations encountered in the cognitive functions studied increased proportionally to time of exposure and quantity of metal absorbed. The study confirmed that occupational exposure to Al causes alteration in cognitive responses that are more evident in complex functions.

  3. 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.

  4. 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",

  5. Photodynamic effect of aluminium and zinc tetrasulfophthalocyanines on melanoma cancer cells

    CSIR Research Space (South Africa)

    Maduray, K

    2010-06-01

    Full Text Available Aluminium and zinc tetrasulfophthalocyanines were activated with a 672nm wavelength laser to investigate the photodynamic effects on melanoma cancer, dermal fibroblast and epidermal keratinocyte cells. Aluminium tetrasulfophthalocyanine was more...

  6. PHASE CONVERSIONS IN METAL-OXIDE COMPOSITIONS ON THE BASIS OF ALUMINIUM AND SILICON OXIDE

    OpenAIRE

    2010-01-01

    The regularities of phase conversions in metal-oxide compositions on the basis of aluminium and silicon oxide with the purpose of silumins synthesis by means of direct restoration of aluminium silicon are studied.

  7. 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.

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

    NARCIS (Netherlands)

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

    2004-01-01

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

  9. 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.

  10. Cancer risk among workers of a secondary aluminium smelter.

    Science.gov (United States)

    Maltseva, A; Serra, C; Kogevinas, M

    2016-07-01

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

  11. Elevated urinary excretion of aluminium and iron in multiple sclerosis.

    Science.gov (United States)

    Exley, Christopher; Mamutse, Godwin; Korchazhkina, Olga; Pye, Eleanor; Strekopytov, Stanislav; Polwart, Anthony; Hawkins, Clive

    2006-10-01

    Multiple sclerosis (MS) is a chronic, immune-mediated, demyelinating disease of the central nervous system of as yet unknown aetiology. A consensus of opinion has suggested that the disorder is the result of an interplay between environmental factors and susceptibility genes. We have used a battery of analytical techniques to determine if the urinary excretion of i) markers of oxidative damage; ii) iron and iii) the environmental toxin aluminium and its antagonist, silicon, are altered in relapsing-remitting (RRMS) and secondary progressive MS (SPMS). Urinary concentrations of oxidative biomarkers, MDA and TBARS, were not found to be useful indicators of inflammatory disease in MS. However, urinary concentrations of another potential marker for inflammation and oxidative stress, iron, were significantly increased in SPMS (P0.05). Urinary concentrations of aluminium were also significantly increased in RRMS (Paluminium excretion in the former were similar to those observed in individuals undergoing metal chelation therapy. The excretion of silicon was lower in MS and significantly so in SPMS (Paluminium excretion similar to those seen in aluminium intoxication suggested that aluminium may be a hitherto unrecognized environmental factor associated with the aetiology of MS. If aluminium is involved in MS then an increased dietary intake of its natural antagonist, silicon, might be a therapeutic option.

  12. Doclet To Synthesize UML

    Science.gov (United States)

    Barry, Matthew R.; Osborne, Richard N.

    2005-01-01

    The RoseDoclet computer program extends the capability of Java doclet software to automatically synthesize Unified Modeling Language (UML) content from Java language source code. [Doclets are Java-language programs that use the doclet application programming interface (API) to specify the content and format of the output of Javadoc. Javadoc is a program, originally designed to generate API documentation from Java source code, now also useful as an extensible engine for processing Java source code.] RoseDoclet takes advantage of Javadoc comments and tags already in the source code to produce a UML model of that code. RoseDoclet applies the doclet API to create a doclet passed to Javadoc. The Javadoc engine applies the doclet to the source code, emitting the output format specified by the doclet. RoseDoclet emits a Rose model file and populates it with fully documented packages, classes, methods, variables, and class diagrams identified in the source code. The way in which UML models are generated can be controlled by use of new Javadoc comment tags that RoseDoclet provides. The advantage of using RoseDoclet is that Javadoc documentation becomes leveraged for two purposes: documenting the as-built API and keeping the design documentation up to date.

  13. Microfabrication of an anodic oxide film by anodizing laser-textured aluminium

    OpenAIRE

    2007-01-01

    A simple method for the fabrication of microstructures of an aluminium anodic oxide film (anodic alumina) by anodizing laser-textured aluminium is demonstrated. In the process, the aluminium substrate was first textured by a low power laser beam, and then the textured aluminium was subjected to anodizing, to develop a continuous, thick porous layer on the textured surface. Microstructures with a depth of a few to several tens of micrometres were fabricated successfully on the anodic oxide fil...

  14. Influence of Alkali Treatment on the Surface Area of Aluminium Dross

    OpenAIRE

    N. S. Ahmad Zauzi; Zakaria, M. Z. H.; R. Baini; 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...

  15. Does antiperspirant use increase the risk of aluminium-related disease, including Alzheimer's disease?

    Science.gov (United States)

    Exley, C

    1998-03-01

    Aluminium salts are the major constituent of many widely used antiperspirant products. The use of such antiperspirants has been linked with the systemic accumulation of aluminium and an increased risk of Alzheimer's disease. But can the frequent use of aluminium-based antiperspirants lead to the accumulation of toxic levels of aluminium? And are there measures that we can take to reduce such accumulation without reducing the effectiveness of antiperspirants?

  16. 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.

  17. 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

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

    NARCIS (Netherlands)

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

    2008-01-01

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

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

    NARCIS (Netherlands)

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

    2008-01-01

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

  20. 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

  1. 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

  2. Structural perturbation of diphtheria toxoid upon adsorption to aluminium hydroxide adjuvant

    NARCIS (Netherlands)

    Regnier, Marie; Metz, Bernard; Tilstra, Wichard; Hendriksen, Coenraad; Jiskoot, Wim; Norde, Willem; Kersten, Gideon

    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

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

    Science.gov (United States)

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

    2016-01-01

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

  4. 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.

  5. Effect of Heat Treatment on Microstructural Changes in Aluminium Bronze

    Directory of Open Access Journals (Sweden)

    Hájek J.

    2016-09-01

    Full Text Available This paper attempts to summarise the microstructural changes which take place in aluminium bronzes during heat treatment. Another objective of this study was to map the potential of a certain type of aluminium bronzes for undergoing martensitic transformation. The methods, which were chosen for assessing the results of heat treatment with regard to their availability, included measurement of hardness and observation of microstructure using light and scanning electron microscopy, Additional tools for evaluation of microstructure comprised measurement of microhardness and chemical analysis by EDS. An important part of the experiment is observation of microstructural changes in the Jominy bar during the end-quench test. Upon completing experiments of this kind, one can define the heat treatment conditions necessary for obtaining optimum properties. In addition, the paper presents important findings on how to improve the corrosion resistance of aluminium bronzes by special heat treatment sequences.

  6. 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.

  7. Constitutive modelling of aluminium alloy sheet at warm forming temperatures

    Science.gov (United States)

    Kurukuri, S.; Worswick, M. J.; Winkler, S.

    2016-08-01

    The formability of aluminium alloy sheet can be greatly improved by warm forming. However predicting constitutive behaviour under warm forming conditions is a challenge for aluminium alloys due to strong, coupled temperature- and rate-sensitivity. In this work, uniaxial tensile characterization of 0.5 mm thick fully annealed aluminium alloy brazing sheet, widely used in the fabrication of automotive heat exchanger components, is performed at various temperatures (25 to 250 °C) and strain rates (0.002 and 0.02 s-1). In order to capture the observed rate- and temperature-dependent work hardening behaviour, a phenomenological extended-Nadai model and the physically based (i) Bergstrom and (ii) Nes models are considered and compared. It is demonstrated that the Nes model is able to accurately describe the flow stress of AA3003 sheet at different temperatures, strain rates and instantaneous strain rate jumps.

  8. The immunobiology of aluminium adjuvants: how do they really work?

    Science.gov (United States)

    Exley, Christopher; Siesjö, Peter; Eriksson, Håkan

    2010-03-01

    Aluminium adjuvants potentiate the immune response, thereby ensuring the potency and efficacy of typically sparingly available antigen. Their concomitant critical importance in mass vaccination programmes may have prompted recent intense interest in understanding how they work and their safety. Progress in these areas is stymied, however, by a lack of accessible knowledge pertaining to the bioinorganic chemistry of aluminium adjuvants, and, consequently, the inappropriate application and interpretation of experimental models of their mode of action. The objective herein is, therefore, to identify the many ways that aluminium chemistry contributes to the wide and versatile armoury of its adjuvants, such that future research might be guided towards a fuller understanding of their role in human vaccinations.

  9. Application of Anodization Process for Cast Aluminium Surface Properties Enhancement

    Directory of Open Access Journals (Sweden)

    Włodarczyk-Fligier A.

    2016-09-01

    Full Text Available An huge interest is observed in last years in metal matrix composite, mostly light metal based, which have found their applications in many industry branches, among others in the aircraft industry, automotive-, and armaments ones, as well as in electrical engineering and electronics, where one of the most important issue is related to the corrosion resistance, especially on the surface layer of the used aluminium alloys. This elaboration presents the influence of ceramic phase on the corrosion resistance, quality of the surface layer its thickness and structure of an anodic layer formed on aluminium alloys. As test materials it was applied the aluminium alloys Al-Si-Cu and Al-Cu-Mg, for which heat treatment processes and corrosion tests were carried out. It was presented herein grindability test results and metallographic examination, as well. Hardness of the treated alloys with those ones subjected to corrosion process were compared.

  10. 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

  11. Aluminium in parenteral nutrition: a systematic review.

    Science.gov (United States)

    Hernández-Sánchez, A; Tejada-González, P; Arteta-Jiménez, M

    2013-03-01

    Aluminium (Al) toxicity problem in parenteral nutrition solutions (PNS) is decades old and is still unresolved. The aim of this review is to gather updated information about this matter, regarding legislation, manifestations, diagnostics and treatment, patient population at risk and the actions to be taken to limit its accumulation. A structured search using MeSH vocabulary and Title/Abstract searches was conducted in PubMed (http://www.pubmed.gov) up to November 2012. Al is ubiquitous, facilitating its potential for exposure. Nevertheless, humans have several mechanisms to prevent significant absorption and to aid its elimination; therefore, the vast majority of the population is not at risk for Al toxicity. However, when protective gastrointestinal mechanisms are bypassed (for example, parenteral fluids), renal function is impaired (for example, adult patients with renal compromise and neonates) or exposure is high (for example, long-term PNS), Al is prone to accumulate in the body, including manifestations such as impaired neurological development, Alzheimer's disease, metabolic bone disease, dyslipemia and even genotoxic activity. A high Al content in PNS is largely the result of three parenteral nutrient additives: calcium gluconate, inorganic phosphates and cysteine hydrochloride. Despite the legislative efforts, some factors make difficult to comply with the rule and, therefore, to limit the Al toxicity. Unfortunately, manufacturers have not universally changed their processes to obtain a lower Al content of parenteral drug products (PDP). In addition, the imprecise information provided by PDP labels and the high lot-to-lot variation make the prediction of Al content rather inaccurate.

  12. Numerical Modelling of Drawbeads for Forming of Aluminium Alloys

    DEFF Research Database (Denmark)

    Joshi, Y; Christiansen, Peter; Masters, I

    2016-01-01

    The drawbeads in stamping tools are usually designed based on experience from the forming of steel. However, aluminium alloys display different forming behaviour to steels, which is not reflected in the drawbead design for tools used for stamping aluminium. This paper presents experimental results...... from different semi-circular drawbead geometries commonly encountered in automotive dies and compares them to those obtained from Stoughton’s analytical drawbead model and the 2D plane strain drawbead model set up using LS-DYNA.The study was conducted on lubricated NG5754 strips. The results presented...

  13. Aluminium Price Looks Down Due To Increased Capacities

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>Speaking at a recent forum on China’S alumin- ium industry,Wen Xianjun,director of the aluminium branch under China Nonferrous Metals Industry Association,said that the alu- minium price in 2007 looks going downward due to the production capacity expansion out of the high market price last year.He estimates that the downward development of the alumin- ium price in China will be more obvious than that in the rest part of the world.He predicts that in 2007 the average aluminium price in

  14. Towards an understanding of the adjuvant action of aluminium

    Science.gov (United States)

    Marrack, Philippa; McKee, Amy S.; Munks, Michael W.

    2011-01-01

    The efficacy of vaccines depends on the presence of an adjuvant in conjunction with the antigen. Of these adjuvants, the ones that contain aluminium, which were first discovered empirically in 1926, are currently the most widely used. However, a detailed understanding of their mechanism of action has only started to be revealed. In this Timeline article, we briefly describe the initial discovery of aluminium adjuvants and discuss historically important advances. We also summarize recent progress in the field and discuss their implications and the remaining questions on how these adjuvants work. PMID:19247370

  15. Silver coated aluminium microrods as highly colloidal stable SERS platforms.

    Science.gov (United States)

    Pazos-Perez, Nicolas; Borke, Tina; Andreeva, Daria V; Alvarez-Puebla, Ramon A

    2011-08-01

    We report on the fabrication of a novel material with the ability to remain in solution even under the very demanding conditions required for structural and dynamic characterization of biomacromolecule assays. This stability is provided by the increase in surface area of a low density material (aluminium) natively coated with a very hydrophilic surface composed of aluminium oxide (Al(2)O(3)) and metallic silver nanoparticles. Additionally, due to the dense collection of active hot spots on their surface, this material offers higher levels of SERS intensity as compared with the same free and aggregated silver nanoparticles.

  16. Transmittance jump in a thin aluminium layer during laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Bykovsky, N E; Senatsky, Yu V [P N Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Pershin, S M; Samokhin, A A [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2016-02-28

    A jump in the transmittance (from ∼0.1% to ∼50% for ∼1 ns) of an optical gate on a Mylar film (a thin aluminium layer on a Lavsan substrate) irradiated by nanosecond (10{sup -7} – 10{sup -8} s) pulses of a neodymium laser with an intensity up to 0.1 GW cm{sup -2} has been recorded. The mechanism of a fast (10{sup -10} – 10{sup -11} s) increase in the transmittance of the aluminium layer upon its overheating (without boiling) to the metal – insulator phase-transition temperature is discussed. (interaction of laser radiation with matter. laser plasma)

  17. Power quality results in energy efficient aluminium smelter operation

    Energy Technology Data Exchange (ETDEWEB)

    Wiestner, Max

    2010-09-15

    New aluminium smelters consume up to 2400MW of electrical energy making the energy efficiency aspect most important. Power quality, optimised power conversion systems and well engineered power plant interfaces are essential for highest energy efficiency. An early optimisation of the power system design will reduce the capital investment cost for the power plant and smelter substation as well as results in most energy efficient aluminium production. This paper describes and intends to discuss the power quality improvement concepts and designs as well as energy cost reduction opportunities which a high power quality system can achieve.

  18. Prevention of Dealloying in Manganese Aluminium Bronze Propeller: Part II

    Directory of Open Access Journals (Sweden)

    Napachat Tareelap

    2014-03-01

    Full Text Available 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 in seawater to form calcium carbonate film protecting the propeller from corrosion.

  19. Aluminium, beta-amyloid and non-enzymatic glycosylation.

    Science.gov (United States)

    Exley, C; Schley, L; Murray, S; Hackney, C M; Birchall, J D

    1995-05-08

    The non-enzymatic glycosylation of beta-amyloid is implicated in the aetiology of Alzheimer's disease. However, controversy surrounds the nature of any involvement and a potential mechanism has not been fully elucidated. We present evidence of an aluminium-induced aggregation of the A beta P(25-35) peptide and speculate that the mechanism of formation of our ordered beta-amyloid aggregates might involve non-enzymatic glycosylation and/or site-specific crosslinking of beta-amyloid fibrils by atomic aluminium.

  20. Gas accumulation at grain boundaries during 800 MeV proton irradiation of aluminium and aluminium-alloys

    DEFF Research Database (Denmark)

    Singh, Bachu Narain; Horsewell, Andy; Sommer, W. F.;

    1986-01-01

    Samples of pure aluminium (99.9999%) and commercial Al-2.7%Mg(AlMg3) and Al-1.1%Mg-0.5%Si(Al6061) alloys were irradiated with 800 MeV protons at the Los Alamos Meson Physics Facility (LAMPF) at a temperature between 40-100°C to a maximum dose of 0.2 dpa. Transmission electron microscopy (TEM......) showed a complete absence of voids or bubbles in the grain interiors of the aluminium and the aluminium-alloys. Bubbles were clearly visible by TEM at grain boundaries in pure Al and the AlMg3 alloy; but bubbles were not visible in the Al6061 alloy. The bubble density in the AlMg3 alloy was considerably...

  1. 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.

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

    Science.gov (United States)

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

    2012-01-01

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

  3. Carbon treated commercial aluminium alloys as anodes for aluminium-air batteries in sodium chloride electrolyte

    Science.gov (United States)

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

    2016-09-01

    An easy treatment based in carbon layer deposition into aluminium alloys is presented to enhance the performance of Al-air primary batteries with neutral pH electrolyte. The jellification of aluminate in the anode surface is described and avoided by the carbon covering. Treated commercial Al alloys namely Al1085 and Al7475 are tested as anodes achieving specific capacities above 1.2 Ah g-1vs 0.5 Ah g-1 without carbon covering. The influence of the binder proportion in the treatment as well as different carbonaceous materials, Carbon Black, Graphene and Pyrolytic Graphite are evaluated as candidates for the covering. Current densities of 1-10 mA cm-2 are measured and the influence of the alloy explored. A final battery design of 4 cells in series is presented for discharges with a voltage plateau of 2 V and 1 Wh g-1 energy density.

  4. New Investment Rush Brings up Concern for China’s Aluminium Industry

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    <正> Although the blind construction of the electro-lytic aluminium industry has been restricted inChina this year,an investment rush in aluminaand aluminium processing has started,whichhas brought up new concern for the industry.Whether this will follow the route of the much-heated electrolytic aluminium industry remainsa question to be answered.According to someindustry analysts,under the pressure of themacro control measures of the State on theelectrolytic aluminium industry expansion,some producers of aluminium have shiftedtheir interests to the upper and lower fields soas to raise their competitiveness over the mar-

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

    Science.gov (United States)

    Nayak, P; Chatterjee, A K

    2001-12-01

    It has been postulated that the neurotoxic effects of aluminium could be mediated through glutamate, an excitatory amino acid. Hence the effects of aluminium administration (at a dose of 4.2mg/kg body weight daily as aluminium chloride, hexahydrate, intraperitoneally, for 4 weeks) on glutamate and gamma-amino butyrate (GABA), an inhibitory amino acid, and related enzyme activities in different regions of the brain were studied in albino rats. The glutamate level increased significantly in the cerebrum, thalamic area, midbrain-hippocampal region and cerebellum in response to in vivo aluminium exposure. The aluminium insult also caused significant increases in glutamate alpha-decarboxylase activity in all the brain regions. However, on aluminium insult, the GABA content was not significantly changed except in the thalamic area, where it was elevated. On the contrary, the GABA-T activities of all the regions were reduced significantly in all regions except the midbrain-hippocampal region. However, the succinic semi-aldehyde content of all brain regions increased, often significantly. The aluminium-induced modification of the enzyme activities may be either due to the direct impact of aluminium or due to aluminium-induced changes in the cellular environment. The aluminium-induced differential regional accumulation of glutamate or other alterations in enzymes of the glutamate-GABA system may be one of the causes of aluminium-induced neurotoxicity.

  6. Facile synthesis of aluminium doped zinc oxide-polyaniline hybrids for photoluminescence and enhanced visible-light assisted photo-degradation of organic contaminants

    Science.gov (United States)

    Mitra, Mousumi; Ghosh, Amrita; Mondal, Anup; Kargupta, Kajari; Ganguly, Saibal; Banerjee, Dipali

    2017-04-01

    The emergence of organic-inorganic photoactive materials has led to marked progress in the field of heterogeneous visible-light photocatalysis. Visible-light active aluminium doped zinc oxide-polyaniline (PAZ) hybrid was prepared employing in-situ oxidative polymerization of polyaniline (PANI) in the presence of aluminium doped zinc oxide (AlZnO) nanorods, synthesized via sol-gel route. The compositions, structural and optical properties of the synthesized hybrids were characterized. Among various samples, the 22 wt% aluminium doped zinc oxide-polyaniline (PAZ 3) hybrid show the best photocatalytic action for the degradation of methyl orange (MO) and rose bengal (RB) dyes under visible-light illumination, even after repeated use. The performance of the photocatalytic process was determined by the first order rate constant, 1.77 × 10-2 min-1 and 2.61 × 10-2 min-1 for MO and RB dyes, respectively. Scavenger test was used to determine the role of active species and accordingly a mechanism was proposed. Electrochemical impedance spectroscopy and linear scan voltammetry under dark and visible-light irradiation also established the visible-light activity of the PAZ hybrid due to decrease in the electron transfer resistance that resulted in an enhancement in photocurrent. The significant enhancement of photo degradation may be attributed to the efficiency of charge separation, induced by synergistic effect between an organic conductor PANI and an inorganic semiconductor AlZnO. Owing to its superior photo electrochemical performance and photocatalytic degradation, aluminium doped zinc oxide-polyaniline (PAZ) hybrid offers stable and efficient organic-inorganic hybrid hetero-structures in near future.

  7. Aluminium foams. manufacture, properties and applications; Espuma de aluminio. Fabricacion, propiedades y aplicaciones

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez-Vazquez, J. a.; Onoro, J.

    2008-07-01

    Aluminium foams are porous to have many interesting combinations of physical and mechanical properties, such as high stiffness in conjunction with very low specific weight. The aluminium foam structure, manufacture processes, physical, chemical and mechanical properties and applications are reviewed in this paper. The various manufacturing processes are classified according to the state of matter in which the metal is processed. Liquid aluminium can be foamed directly by injecting gas or gas-releasing blowing agents. Indirect methods include melting of powder compacts which contain a blowing agent. An inert gas entrapped in powder compacts can produce aluminium foams in solid state after heat treatment. Electron-deposition or metal vapour deposition also allow for the production of aluminium foams. Physical, chemical and mechanical properties and the various ways for characterising the aluminium foams are reviewed in second section of this paper. finally, the various application fields for aluminium foams are discussed. They are divided into different industrial sectors. (Author) 75 refs.

  8. Investigation of concrete produced using recycled aluminium dross for hot weather concreting conditions

    Directory of Open Access Journals (Sweden)

    Gireesh Mailar

    2016-06-01

    Full Text Available Aluminium dross is a by-product obtained from the aluminium smelting process. Currently, this dross is processed in rotary kilns to recover the residual aluminium, and the resultant salt cake is sent to landfills. The present study investigates the utilization of recycled aluminium dross in producing concrete, which is suitable for hot weather concreting condition. The primary objectives of the experimental study are to examine the feasibility of using concrete blended with recycled aluminium dross under hot weather concreting situations and then to evaluate the strength and durability aspects of the produced concrete. From the experimental results it is observed that the initial setting time of the recycled aluminium dross concrete extended by about 30 minutes at 20% replacement level. This property of recycled aluminium dross concrete renders it to be suitable for hot weather concreting conditions. Based on the results obtained, the replacement of cement with 20% of Al dross yields superior mechanical and durability characteristics.

  9. Establishment of integrated information displays in aluminium surfaces using nanomanufacturing

    DEFF Research Database (Denmark)

    Prichystal, Jan; Hansen, Hans Nørgaard; Bladt, Henrik H.

    2006-01-01

    in aluminium concerns the processing of a metal workpiece in such a way that microcavities are formed from the backside of the workpiece. The microcavities must not penetrate the metal front side, but an ultra-thin layer of metal is left. It is possible to shine light through this layer. By ordering...

  10. Three-particle correlations in liquid and amorphous aluminium

    Science.gov (United States)

    Galimzyanov, Bulat N.; Mokshin, Anatolii V.

    2017-07-01

    Analysis of three-particle correlations is performed on the basis of simulation data of atomic dynamics in liquid and amorphous aluminium. A three-particle correlation function is introduced to characterize the relative positions of various three particles-the so-called triplets. Various configurations of triplets are found by calculation of pair and three-particle correlation functions. It was found that in the case of liquid aluminium with temperatures 1000 K, 1500 K, and 2000 K the three-particle correlations are more pronounced within the spatial scales, comparable with a size of the second coordination sphere. In the case of amorphous aluminium with temperatures 50 K, 100 K, and 150 K these correlations in the mutual arrangement of three particles are manifested up to spatial scales, which are comparable with a size of the third coordination sphere. Temporal evolution of three-particle correlations is analyzed by using a time-dependent three-particle correlation function, for which an integro-differential equation of type of the generalized Langevin equation is output with help of projection operators technique. A solution of this equation by means of mode-coupling theory is compared with our simulation results. It was found that this solution correctly reproduces the behavior of the time-dependent three-particle correlation functions for liquid and amorphous aluminium.

  11. Persistent Skin Reactions and Aluminium Hypersensitivity Induced by Childhood Vaccines

    DEFF Research Database (Denmark)

    Salik, Elaha; Løvik, Ida; Andersen, Klaus E

    2016-01-01

    . Two patients had skin biopsies performed from their skin lesions, and 2 patients had the nodules surgically removed. Forty-two children had a patch-test performed with 2% aluminium chloride hexahydrate in petrolatum and 39 of them (92%) had a positive reaction. The persistent skin reactions were...

  12. Local electrochemical behaviour of 7xxx aluminium alloys

    NARCIS (Netherlands)

    Andreatta, F.

    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 neg

  13. Novel package for inhibition of aluminium corrosion in alkaline solutions

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Gaber, A.M., E-mail: ashrafmoustafa@yahoo.com [Chemistry Department, Faculty of Science, Alexandria University, Ibrahimia, P.O. Box 426, Alexandria 21321 (Egypt); Khamis, E.; Abo-Eldahab, H.; Adeel, Sh. [Chemistry Department, Faculty of Science, Alexandria University, Ibrahimia, P.O. Box 426, Alexandria 21321 (Egypt)

    2010-11-01

    Inhibition of aluminium corrosion in 2 M sodium hydroxide solution by a package composed of the cationic surfactant cetyl trimethyl ammonium bromide (CTAB) and lupine seed extract has been investigated employing different electrochemical techniques and chemical gasometry measurements. Potentiodynamic polarization curve measurements showed that lupine seed extract controls both the anodic dissolution of aluminium and the hydrogen gas evolved at the cathodic sites of aluminium surface. Nyquist plots showed two capacitive semicircles in the high and low frequency regions separated by an inductive loop at intermediate frequencies. The inductive loop may be explained by the occurrence of adsorbed intermediates on the surface. A proposed equivalent circuit was used to analyse the impedance spectra for aluminium in NaOH solutions. The corrosion inhibition data have been analysed using different isotherms. The results showed excellent agreement between the kinetic-thermodynamic model and Flory-Huggins isotherm. Gasometry measurements showed that the Inhibitive effect of the surfactant increases at a composition around its critical micelle concentration (cmc). The presence of both the surfactant and lupine seed extract did not indicate synergistic action between them. The mode of adsorption of the surfactant molecules corresponding to their structure is also discussed.

  14. Development of an aluminium stabilized reinforced superconducting conductor

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-07-01

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

  15. Diamond turning and polishing tests on new RSP aluminium alloys

    NARCIS (Netherlands)

    Horst, R. ter; Haan, M. de; Gubbels, G.P.H.; Senden, R.; Venrooy, B.W.H. van; Hoogstrate, A.M.

    2012-01-01

    For years now conventional aluminium 6061 T6 has widely been used for mirrors in astronomical instruments, being diamond turned or since a few years also being optically polished. This allows the development of optical systems that can be tested and operated at any temperature, without being affecte

  16. Examples on cold forged aluminium components in automotive industry

    DEFF Research Database (Denmark)

    Bay, Niels; Kolsgaard, A.

    2000-01-01

    The present paper describes the possibilites of applying cold forging for manufacturing of light weight components in aluminium. A short description of the basic cold forming processes forms the basis for describing the great variety in design of cold forged components. Examples are mainly taken ...

  17. Zonal distribution of dissolved aluminium in the Mediterranean Sea

    NARCIS (Netherlands)

    Rolison, J. M.; Middag, R.; Stirling, C. H.; Rijkenberg, M. J. A.; de Baar, H. J. W.

    2015-01-01

    Dissolved aluminium (Al) is an important tracer of atmospheric dust input to the oceans. The GEOTRACES expedition to the highly dust impacted Mediterranean Sea afforded the opportunity to study the distribution of dissolved Al in the Mediterranean Sea in detail. Interestingly, the elevated concentra

  18. Cavitation-aided grain refinement in aluminium alloys

    NARCIS (Netherlands)

    Atamanenko, T.V.

    2010-01-01

    This thesis deals with grain refinement under the influence of ultrasonic-driven cavitation in aluminium casting processes. Three major goals of this research were: (1) to identify the mechanism of the cavitation-aided grain refinement at different stages of solidification; (2) to reveal the

  19. A vector valued Stefan problem from aluminium industry

    NARCIS (Netherlands)

    F.J. Vermolen; C. Vuik

    1998-01-01

    textabstractDissolution of stoichiometric multi-component particles in ternary alloys is an important process occurring during the heat treatment of as-cast aluminium alloys prior to hot-extrusion. A mathematical model is proposed to describe such a process. In this model an equation is given to

  20. Mechanochemical route to the synthesis of nanostructured Aluminium nitride

    Science.gov (United States)

    Rounaghi, S. A.; Eshghi, H.; Scudino, S.; Vyalikh, A.; Vanpoucke, D. E. P.; Gruner, W.; Oswald, S.; Kiani Rashid, A. R.; Samadi Khoshkhoo, M.; Scheler, U.; Eckert, J.

    2016-09-01

    Hexagonal Aluminium nitride (h-AlN) is an important wide-bandgap semiconductor material which is conventionally fabricated by high temperature carbothermal reduction of alumina under toxic ammonia atmosphere. Here we report a simple, low cost and potentially scalable mechanochemical procedure for the green synthesis of nanostructured h-AlN from a powder mixture of Aluminium and melamine precursors. A combination of experimental and theoretical techniques has been employed to provide comprehensive mechanistic insights on the reactivity of melamine, solid state metal-organic interactions and the structural transformation of Al to h-AlN under non-equilibrium ball milling conditions. The results reveal that melamine is adsorbed through the amine groups on the Aluminium surface due to the long-range van der Waals forces. The high energy provided by milling leads to the deammoniation of melamine at the initial stages followed by the polymerization and formation of a carbon nitride network, by the decomposition of the amine groups and, finally, by the subsequent diffusion of nitrogen into the Aluminium structure to form h-AlN.

  1. Tailored Aluminium based Coatings for Optical Appearance and Corrosion Resistance

    DEFF Research Database (Denmark)

    Aggerbeck, Martin

    The current project investigated the possibility of designing aluminium based coatings focusing on the effect of composition and surface finish on the optical appearance and on the alkaline corrosion properties using titanium as the main alloying element. The main results and discussions of this ......The current project investigated the possibility of designing aluminium based coatings focusing on the effect of composition and surface finish on the optical appearance and on the alkaline corrosion properties using titanium as the main alloying element. The main results and discussions...... the optical appearance is affected by the alloy composition, surface morphology, and the microstructure. Four commercial aluminium alloys were studied before and after polishing, etching, anodisation, and hot water sealing, giving an overview on how the alloy composition affects the appearance. It was found...... that the roughness after etching increases with higher amounts of alloying elements (especially iron and silicon). Proper polishing requires some alloy hardness, while alloy purity is required for a glossy appearance after anodisation. Magnetron sputtered aluminium based coatings containing up to 18 wt. % titanium...

  2. Impact toughness of laser alloyed aluminium AA1200 alloys

    CSIR Research Space (South Africa)

    Mabhali, Luyolo AB

    2013-08-01

    Full Text Available Laser surface alloying of aluminium AA1200 was performed with a 4kW Nd:YAG laser and impact resistance of the alloys was investigated. The alloying powders were a mixture of Ni, Ti and SiC in different proportions. Surfaces reinforced...

  3. Molecular Characterization of Aluminium (aluminum) Tolerance in Rye

    Science.gov (United States)

    Aluminium (Al) toxicity, affecting around half of the world’s arable land, severely hinders the ability of crop plants to utilize moisture and nutrients by restricting root growth and function. Among the cultivated cereals, rye is the most Al-tolerant and represents an important potential source of ...

  4. Porphyry copper enrichment linked to excess aluminium in plagioclase

    Science.gov (United States)

    Williamson, B. J.; Herrington, R. J.; Morris, A.

    2016-03-01

    Porphyry copper deposits provide around 75%, 50% and 20% of world copper, molybdenum and gold, respectively. The deposits are mainly centred on calc-alkaline porphyry magmatic systems in subduction zone settings. Although calc-alkaline magmas are relatively common, large porphyry copper deposits are extremely rare and increasingly difficult to discover. Here, we compile existing geochemical data for magmatic plagioclase, a dominant mineral in calc-alkaline rocks, from fertile (porphyry-associated) and barren magmatic systems worldwide, barren examples having no associated porphyry deposit. We show that plagioclase from fertile systems is distinct in containing `excess’ aluminium. This signature is clearly demonstrated in a case study carried out on plagioclase from the fertile La Paloma and Los Sulfatos copper porphyry systems in Chile. Further, the presence of concentric zones of high excess aluminium suggests its incorporation as a result of magmatic processes. As excess aluminium has been linked to high melt water contents, the concentric zones may record injections of hydrous fluid or fluid-rich melts into the sub-porphyry magma chamber. We propose that excess aluminium may exclude copper from plagioclase, so enriching the remaining melts. Furthermore, this chemical signature can be used as an exploration indicator for copper porphyry deposits.

  5. Cavitation-aided grain refinement in aluminium alloys

    NARCIS (Netherlands)

    Atamanenko, T.V.

    2010-01-01

    This thesis deals with grain refinement under the influence of ultrasonic-driven cavitation in aluminium casting processes. Three major goals of this research were: (1) to identify the mechanism of the cavitation-aided grain refinement at different stages of solidification; (2) to reveal the conditi

  6. Aluminium in food and daily dietary intake estimate in Greece.

    Science.gov (United States)

    Bratakos, Sotirios M; Lazou, Andriana E; Bratakos, Michael S; Lazos, Evangelos S

    2012-01-01

    Aluminium content of foods, as well as dietary aluminium intake of the Greek adult population, was determined using graphite furnace atomic absorption spectroscopy after microwave sample digestion and food consumption data. Al content ranged from 0.02 to 741.2 mg kg⁻¹, with spices, high-spice foods, cereal products, vegetables and pulses found to be high in Al. Differences in aluminium content were found between different food classes from Greece and those from some other countries. Aluminium intake of Greeks is 3.7 mg/day based on DAFNE Food Availability Databank, which uses data from the Household Budget Surveys. On the other hand, according to the per capita food consumption data collected by both national and international organisations, Al intake is 6.4 mg day⁻¹. Greek adult population has an Al intake lower than the Provisional Tolerable Weekly Intake of 7 mg kg⁻¹ body weight established by EFSA. Cereals and vegetables are the main Al contributors, providing 72.4% of daily intake.

  7. Mechanochemical route to the synthesis of nanostructured Aluminium nitride.

    Science.gov (United States)

    Rounaghi, S A; Eshghi, H; Scudino, S; Vyalikh, A; Vanpoucke, D E P; Gruner, W; Oswald, S; Kiani Rashid, A R; Samadi Khoshkhoo, M; Scheler, U; Eckert, J

    2016-09-21

    Hexagonal Aluminium nitride (h-AlN) is an important wide-bandgap semiconductor material which is conventionally fabricated by high temperature carbothermal reduction of alumina under toxic ammonia atmosphere. Here we report a simple, low cost and potentially scalable mechanochemical procedure for the green synthesis of nanostructured h-AlN from a powder mixture of Aluminium and melamine precursors. A combination of experimental and theoretical techniques has been employed to provide comprehensive mechanistic insights on the reactivity of melamine, solid state metal-organic interactions and the structural transformation of Al to h-AlN under non-equilibrium ball milling conditions. The results reveal that melamine is adsorbed through the amine groups on the Aluminium surface due to the long-range van der Waals forces. The high energy provided by milling leads to the deammoniation of melamine at the initial stages followed by the polymerization and formation of a carbon nitride network, by the decomposition of the amine groups and, finally, by the subsequent diffusion of nitrogen into the Aluminium structure to form h-AlN.

  8. Modelling aluminium wire bond reliability in high power OMP devices

    NARCIS (Netherlands)

    Kregting, R.; Yuan, C.A.; Xiao, A.; Bruijn, F. de

    2011-01-01

    In a RF power application such as the OMP, the wires are subjected to high current (because of the high power) and high temperature (because of the heat from IC and joule-heating from the wire itself). Moreover, the wire shape is essential to the RF performance. Hence, the aluminium wire is preferre

  9. Electrochemical Characterisation of Filiform Corrosion on Aluminium Rolled Products

    NARCIS (Netherlands)

    Huisert, M.

    2001-01-01

    When aluminium is protected by an organic coating a special form of corrosion can occur underneath the organic coating; filiform corrosion. This form of corrosion manifests itself as threadlike filaments under the coating, it causes local delamination of the coating and the coating cannot protect th

  10. Reactive ion beam figuring of optical aluminium surfaces

    Science.gov (United States)

    Bauer, Jens; Frost, Frank; Arnold, Thomas

    2017-03-01

    Ultra-smooth and arbitrarily shaped reflective optics are necessary for further progress in EUV/XUV lithography, x-ray and synchrotron technology. As one of the most important technological mirror optic materials, aluminium behaves in a rather difficult way in ultra-precision machining with such standard techniques as diamond-turning and subsequent ion beam figuring (IBF). In particular, in the latter, a strong surface roughening is obtained. Hence, up to now it has not been possible to attain the surface qualities required for UV or just visible spectral range applications. To overcome the limitations mainly caused by the aluminium alloy structural and compositional conditions, a reactive ion beam machining process using oxygen process gas is evaluated. To clarify the principle differences in the effect of oxygen gas contrary to oxygen ions on aluminium surface machining, we firstly focus on chemical-assisted ion beam etching (CAIBE) and reactive ion beam etching (RIBE) experiments in a phenomenological manner. Then, the optimum process route will be explored within a more quantitative analysis applying the concept of power spectral density (PSD) for a sophisticated treatment of the surface topography. Eventually, the surface composition is examined by means of dynamic secondary ion mass spectrometry (SIMS) suggesting a characteristic model scheme for the chemical modification of the aluminium surface during oxygen ion beam machining. Monte Carlo simulations were applied to achieve a more detailed process conception.

  11. Silicon Carbide Tiles for Sidewall Lining in Aluminium Electrolysis Cells

    Institute of Scientific and Technical Information of China (English)

    RUANBo; ZHAOJunguo; 等

    1999-01-01

    The paper introduces the nitride bonded silicon carbide used for sidewall lining in aluminium eletrolysis cells ,including technical process,main properties and application results.Comparison tests on various physical properties of silicon carbide products made by LIRR and other producers worldwide have also been conducted in an independent laboratory.

  12. Treatment of dairy effluents by electrocoagulation using aluminium electrodes.

    Science.gov (United States)

    Tchamango, Serge; Nanseu-Njiki, Charles P; Ngameni, Emmanuel; Hadjiev, Dimiter; Darchen, André

    2010-01-15

    This work sets out to examine the efficiency of an electrolytic treatment: electrocoagulation, applied to dairy effluents. The experiments were carried out using a soluble aluminium anode on artificial wastewater derived from solutions of milk powder. The flocks generated during this treatment were separated by filtration. The analysis of the filtrates showed that the chemical oxygen demand (COD) was reduced by up to 61% while the removal of phosphorus, nitrogen contents, and turbidity were 89, 81 and 100%, respectively. An analogous treatment applied to phosphate and lactose solutions revealed that lactose was not eliminated, a fact that could account for the rather poor lowering of the COD. Compared to the chemical coagulation treatment with aluminium sulphate, the efficiency of the electrocoagulation technique was almost identical. However the wastewaters treated by electrocoagulation differed by the fact that they exhibited a lower conductivity and a neutral pH value (by contrast to the acid nature of the solution treated by the chemical coagulation). This result (low conductivity, neutral pH) tends to show that it may be possible to recycle the treated water for some industrial uses. Moreover, the electrocoagulation process uses fewer reagents: the mass of the aluminium anode dissolved during the treatment is lower compared to the quantity of the aluminium salt used in chemical coagulation. These two observations clearly show that the electrocoagulation technique is more performing.

  13. Highly sensitive thermoluminescent carbon doped nanoporous aluminium oxide detectors.

    Science.gov (United States)

    de Azevedo, W M; de Oliveira, G B; da Silva, E F; Khoury, H J; Oliveira de Jesus, E F

    2006-01-01

    In this work we present the synthesis, characterisation and the thermoluminescence (TL) response of nanoporous carbon doped aluminium oxide Al2O3:C produced by anodic oxidation of aluminium in organic and inorganic solvents. The X-ray and scanning electron microscopy (SEM) measurements reveal that the synthesised samples are amorphous and present highly ordered structures with uniform pore distribution with diameter of the order 50 nm. The photoluminescence and spectroscopic analysis in the visible and infrared regions show that the luminescence properties presented by the samples prepared in organic acid are due to carboxylate species, incorporated in anodic alumina films during the synthesis process. After an annealing treatment, part of the incorporated species decomposes and is incorporated into the structure of the aluminium oxide yielding a highly thermoluminescent detector (TL) . The results for X-ray irradiation in the range from 21 to 80 keV indicate a linear TL response with the dose in the range from 5 mGy to 1 Gy, suggesting that nanoporous aluminium oxide produced in the present route of synthesis is a suitable detector for radiation measurements.

  14. Energy situation and competitiveness of the aluminium industry

    Energy Technology Data Exchange (ETDEWEB)

    Legler, H.

    1984-04-01

    The west german aluminium industry has heavily run into the wake of price competition; the high energy price level in the FRG in international comparison carries heavy weight. The technological potential of energy saving is limited. The electricity prices to aluminium smelters are politically determined: They depend on the importance which economic policy attaches to the competitiveness of electricity intensive industries. Since the end of the seventies the tendency of improved results in international trade has been broken. Other important supply factors are not advantageous. Compared to a lot of other economies the west german aluminium industry invests too little in research and development. Although the share of unskilled workers is high, it does not seem impossible to close the technological gap. - The environmental protection expenditures are considerable. Energy is not the only problem of the aluminium industry Electricity price subsidies do not produce any effect in the long run. The prospects of cheap electricity in comparison with other nations are not bright. Without a doubt the considerable regional and sectoral discriminations in setting electricity prices could be - and have to be - removed. Then the competition within FRG between electricity users would be less heavily distorted. The electricity price level will tend to drop significantly in an economy which applies more competitive pressure to power companies than today.

  15. Three body abrasion of laser surface alloyed aluminium AA1200

    CSIR Research Space (South Africa)

    Mabhali, Luyolo AB

    2012-06-01

    Full Text Available on the composition of the alloying powder mixture. The wear performance of the alloyed surfaces was characterised using an ASTM G65 three body dry abrasion apparatus. A maximum 82% improvement in the wear resistance of the pure aluminium was achieved with a 40 wt% Ni...

  16. Research Regarding Aluminium Eloxation from Phosphoric Acid Electrolyte

    Directory of Open Access Journals (Sweden)

    Cretu Carmen Monica

    2014-06-01

    Full Text Available The study presents the influence of production parameters on the aluminium eloxation from H3PO4 solution. The thickness and aspect of the deposited Al2O3 were determined. The electrodeposition experiments was to determine the optimum conditions for the producing of bright, continuous, adherent and compact Al2O3 layers.

  17. Effects of Aluminium in Forest. Results of a pilot experiment

    Energy Technology Data Exchange (ETDEWEB)

    Mulder, J.; Wit, H. de; Nygaard, P.H.

    1996-01-01

    This conference paper deals with an Norwegian pilot project which started in 1995 and finishing early 1999, investigates the solubility and phyto-toxicity of aluminium (Al) in mature forest ecosystems. The project consists of three major parts, including field manipulation study of Norwegian spruce stands, laboratory experiments and modelling Al chemistry in the root zone. 15 refs.

  18. Examples on cold forged aluminium components in automotive industry

    DEFF Research Database (Denmark)

    Bay, Niels; Kolsgaard, A.

    2000-01-01

    The present paper describes the possibilites of applying cold forging for manufacturing of light weight components in aluminium. A short description of the basic cold forming processes forms the basis for describing the great variety in design of cold forged components. Examples are mainly taken ...... from automotive industry but in a few cases also from other industrial sectors to show the possibilities....

  19. Aluminium structures exposed to fire conditions. An overview

    NARCIS (Netherlands)

    Maljaars, J.; Twilt, L.; Fellinger, J.H.H.; Snijder, H.H.; Soetens, F.

    2010-01-01

    This paper gives an overview of the structural behaviour and design of aluminium structures exposed to fire conditions. Two design approaches are elaborated: the "traditional" approach that is mainly based on conventions and the fire safety engineering approach that is more based on physics. For the

  20. Electrochemical Characterisation of Filiform Corrosion on Aluminium Rolled Products

    NARCIS (Netherlands)

    Huisert, M.

    2001-01-01

    When aluminium is protected by an organic coating a special form of corrosion can occur underneath the organic coating; filiform corrosion. This form of corrosion manifests itself as threadlike filaments under the coating, it causes local delamination of the coating and the coating cannot protect

  1. Mechanically milled aluminium matrix composites reinforced with halloysite nanotubes

    Directory of Open Access Journals (Sweden)

    L.A. Dobrzański

    2012-12-01

    Full Text Available Purpose: The present work describes fabrication of aluminium AlMg1SiCu matrix composite materials reinforced with halloysite nanotubes by powder metallurgy techniques and hot extrusion.Design/methodology/approach: Mechanical milling, compacting and hot extrusion successively are considering as a method for manufacturing metal composite powders with a controlled fine microstructure and enhanced mechanical properties. It is possible by the repeated welding and fracturing of powders particles mixture in a highly energetic ball mill.Findings: The milling process has a huge influence on the properties of powder materials, changing the spherical morphology of as-received powder during milling process to flattened one due to particle deformation followed by welding and fracturing particles of deformed and hardened enough which allows to receive equiaxial particles morphology again. The investigation shows that so called brittle mineral particles yields to plastic deformation as good as ductile aluminium alloy particles. That indicates that the halloysite powder can play a role of the accelerator during mechanical milling. High energy ball milling as a method of mechanical milling improves the distribution of the halloysite reinforcing particles throughout the aluminium matrix, simultaneously reducing the size of particles. The apparent density changes versus milling time can be used to control the composite powders production by mechanical milling and the presence of halloysite reinforcements particles accelerates the mechanical milling process.Research limitations/implications: Contributes to knowledge about technology, structure and properties of aluminium alloy matrix composite material reinforced with mineral nanoparticles.Practical implications: Conducted research shows that applied technology allows obtaining very good microstructural characteristics.Originality/value: It has been confirmed that halloysite nanotubes can be applied as an effective

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

    Energy Technology Data Exchange (ETDEWEB)

    Vera, Rosa, E-mail: rvera@ucv.c [Instituto de Quimica, Facultad de Ciencias, Pontificia Universidad Catolica de Valparaiso, Avda. Brasil 2950, Casilla 4059, Valparaiso (Chile); Verdugo, Patricia [Departamento de Quimica y Bioquimica, Facultad de Ciencias, Universidad de Valparaiso, Av. Gran Bretana 1111, Valparaiso (Chile); Orellana, Marco; Munoz, Eduardo [Instituto de Quimica, Facultad de Ciencias, Pontificia Universidad Catolica de Valparaiso, Avda. Brasil 2950, Casilla 4059, Valparaiso (Chile)

    2010-11-15

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

  3. Decreased toxicity of aluminium when the ionic strength increases in water; Blir aluminium mindre toksisk naar ionestyrken i vannet oeker?

    Energy Technology Data Exchange (ETDEWEB)

    Alstad, E.W. [Oslo Univ. (Norway)

    1996-01-01

    The conference paper evaluates the acute mortality of fish caused by the toxicity of aluminium in water. The evaluation is based on the polymerization hypothesis. According to the author, the level of toxicity decreases when the concentration and charge of ions increase. The paper presents the preliminary results from the executed experiment. 2 refs., 2 figs., 1 tab.

  4. Energy conversion from aluminium and phosphate rich solution via ZnO activation of aluminium

    Energy Technology Data Exchange (ETDEWEB)

    Slaughter, Gymama, E-mail: gslaught@umbc.edu; Sunday, Joshua; Stevens, Brian

    2015-08-01

    Electrochemical power sources have motivated intense research efforts in the development of alternative ‘green’ power sources for ultra-low powered bioelectronic devices. Biofuel cells employ immobilized enzymes to convert the available chemical energy of organic fuels directly into electricity. However, biofuel cells are limited by short lifetime due to enzyme inactivation and frequent need to incorporate mediators to shuttle electrons to the final electron acceptor. In this context, other electrochemical power sources are necessary in energy conversion and storage device applications. Here we report on the fabrication and characterization of a membrane-free aluminium/phosphate cell based on the activation of aluminium (Al) using ZnO nanocrystal in an Al/phosphate cell as a ‘green’ alternative to the traditional enzymatic biofuel cells. The hybrid cell operates in neutral phosphate buffer solution and physiological saline buffer. The ZnO modifier in the phosphate rich electrolyte activated the pitting of Al resulting in the production of hydrogen, as the reducing agent for the reduction of H{sub 2}PO{sub 4}{sup −} ions to HPO{sub 3}{sup 2−} ions at a formal potential of −0.250 V vs. Ag/AgCl. Specifically, the fabricated cell operating in phosphate buffer and physiological saline buffer exhibit an open-circuit voltage of 0.810 V and 0.751 V and delivered a maximum power density of 0.225 mW cm{sup −2} and 1.77 mW cm{sup −2}, respectively. Our results demonstrate the feasibility of generating electricity by activating Al as anodic material in a hybrid cell supplied with phosphate rich electrolyte. Our approach simplifies the construction and operation of the electrochemical power source as a novel “green” alternative to the current anodic substrates used in enzymatic biofuel cells for low power bioelectronics applications. - Graphical abstract: Display Omitted - Highlights: • ZnO activation of metallic Al for generating electricity for

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

    Science.gov (United States)

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

    2013-01-01

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

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

    Directory of Open Access Journals (Sweden)

    J.O. Agunsoye

    2015-03-01

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

  7. Effects of Nano-Aluminium on The Combustion of A PolyNIMMO-Based Propellant

    Institute of Scientific and Technical Information of China (English)

    Clive Woodley; Peter Henning

    2014-01-01

    Propellants containing micro-aluminium particles have been shown to produce faster burn rates than conventional gun propellants.However,they are also more abrasive than conventional propellants.Nano-material propellants have been reported to give similar benefits to micron-material propellants but without the disadvantage of increased abrasion.Tests were conducted to compare the burn rates,ignitability and wear rates of a propellant loaded with 0% aluminium,15% micro-aluminium and 15%nano-aluminium.Closed vessel tests showed a burn rate increase of 39% in the range 30-250 MPa,and 70% at low pressure (50-100 MPa)for the nano-aluminium propellant compared with the baseline propellant.The micro-aluminium propellant showed only a 10% increase in the burn rate compared with the standard propellant.The ignition delay for the nano-aluminium propellant was slightly shorter than that of the baseline propellant.Substantially increased wear rates were measured for the micro-aluminium propellant.The nano-aluminium propellant showed reduced wear rates compared with the micro-aluminium propellant but these were still substantially greater than those for the baseline propellant.

  8. Elevated urinary aluminium in current and past users of illicit heroin.

    Science.gov (United States)

    Exley, Christopher; Ahmed, Usman; Polwart, Anthony; Bloor, Roger N

    2007-06-01

    The use of illicit heroin is associated with aberrant neurology of unknown aetiology and various psychiatric illnesses. Aluminium, which is a proven neurotoxin, is present in significant amounts in illicit heroin and may also be volatilized and inhaled following the vaporization of heroin off aluminium foil ('Chasing the Dragon'). The purpose of this study was to establish if the use of illicit heroin was associated with an increase in the body burden of aluminium. We have used graphite furnace atomic absorption spectrometry to measure the aluminium and iron contents of the urine of current and past users of illicit heroin and used these data to estimate body burdens of aluminium. Urinary excretion of aluminium is the most effective non-invasive indicator of the body burden of aluminium and was found to be significantly (P aluminium from the use of illicit heroin may be of particular significance because the urinary excretion of iron, another major contaminant of illicit heroin, in users (mean +/- SD; 53 +/- 63 nmol/mmol creatinine) was not significantly different (P > 0.05) from the control population (mean +/- SD; 38 +/- 18 nmol/mmol creatinine). We have shown for the first time that the use of illicit heroin may be a significant contributor to the body burden of aluminium. Further research will be required to determine if adventitious aluminium has a role in heroin use-related neuropathology and neurology.

  9. Non-invasive therapy to reduce the body burden of aluminium in Alzheimer's disease.

    Science.gov (United States)

    Exley, Christopher; Korchazhkina, Olga; Job, Deborah; Strekopytov, Stanislav; Polwart, Anthony; Crome, Peter

    2006-09-01

    There are unexplained links between human exposure to aluminium and the incidence, progression and aetiology of Alzheimer's disease. The null hypothesis which underlies any link is that there would be no Alzheimer's disease in the effective absence of a body burden of aluminium. To test this the latter would have to be reduced to and retained at a level that was commensurate with an Alzheimer's disease-free population. In the absence of recent human interference in the biogeochemical cycle of aluminium the reaction of silicic acid with aluminium has acted as a geochemical control of the biological availability of aluminium. This same mechanism might now be applied to both the removal of aluminium from the body and the reduced entry of aluminium into the body while ensuring that essential metals, such as iron, are unaffected. Based upon the premise that urinary aluminium is the best non-invasive estimate of body burden of aluminium patients with Alzheimer's disease were asked to drink 1.5 L of a silicic acid-rich mineral water each day for five days and, by comparison of their urinary excretion of aluminium pre-and post this simple procedure, the influence upon their body burden of aluminium was determined. Drinking the mineral water increased significantly (Paluminium (86.0 +/- 24.3 to 62.2 +/- 23.2 nmol/mmol creatinine). The latter was achieved without any significant (P>0.05) influence upon the urinary excretion of iron (20.7 +/- 9.5 to 21.7 +/- 13.8 nmol/mmol creatinine). The reduction in urinary aluminium supported the future longer-term use of silicic acid as non-invasive therapy for reducing the body burden of aluminium in Alzheimer's disease.

  10. Aluminium content of foods originating from aluminium-containing food additives.

    Science.gov (United States)

    Ogimoto, Mami; Suzuki, Kumi; Haneishi, Nahoko; Kikuchi, Yuu; Takanashi, Mayu; Tomioka, Naoko; Uematsu, Yoko; Monma, Kimio

    2016-09-01

    Aluminium (Al) levels of 90 food samples were investigated. Nineteen samples contained Al levels exceeding the tolerable weekly intake (TWI) for young children [body weight (bw): 16 kg] when consuming two servings/week. These samples were purchased multiple times at specific intervals and were evaluated for Al levels. Al was detected in 27 of the 90 samples at levels ranging from 0.01 (limit of quantitation) to 1.06 mg/g. Of these, the Al intake levels in two samples (cookie and scone mix, 1.3 and 2 mg/kg bw/week, respectively) exceeded the TWI as established by European Food Safety Authority, although the level in the scone mix was equivalent to the provisional TWI (PTWI) as established by Joint Food and Agriculture Organization of the United Nations/World Health Organization Expert Committee on Food Additives. The Al levels markedly decreased in 14 of the 19 samples with initially high Al levels. These results indicated reductions in the Al levels to below the PTWI limits in all but two previously identified food samples.

  11. RAMESES publication standards: realist syntheses

    Directory of Open Access Journals (Sweden)

    Wong Geoff

    2013-01-01

    Full Text Available Abstract Background There is growing interest in realist synthesis as an alternative systematic review method. This approach offers the potential to expand the knowledge base in policy-relevant areas - for example, by explaining the success, failure or mixed fortunes of complex interventions. No previous publication standards exist for reporting realist syntheses. This standard was developed as part of the RAMESES (Realist And MEta-narrative Evidence Syntheses: Evolving Standards project. The project's aim is to produce preliminary publication standards for realist systematic reviews. Methods We (a collated and summarized existing literature on the principles of good practice in realist syntheses; (b considered the extent to which these principles had been followed by published syntheses, thereby identifying how rigor may be lost and how existing methods could be improved; (c used a three-round online Delphi method with an interdisciplinary panel of national and international experts in evidence synthesis, realist research, policy and/or publishing to produce and iteratively refine a draft set of methodological steps and publication standards; (d provided real-time support to ongoing realist syntheses and the open-access RAMESES online discussion list so as to capture problems and questions as they arose; and (e synthesized expert input, evidence syntheses and real-time problem analysis into a definitive set of standards. Results We identified 35 published realist syntheses, provided real-time support to 9 on-going syntheses and captured questions raised in the RAMESES discussion list. Through analysis and discussion within the project team, we summarized the published literature and common questions and challenges into briefing materials for the Delphi panel, comprising 37 members. Within three rounds this panel had reached consensus on 19 key publication standards, with an overall response rate of 91%. Conclusion This project used multiple

  12. Kinetics of intercalation of fluorescent probes in magnesium-aluminium layered double hydroxide within a multiscale reaction-diffusion framework

    Science.gov (United States)

    Saliba, Daniel; Al-Ghoul, Mazen

    2016-11-01

    We report the synthesis of magnesium-aluminium layered double hydroxide (LDH) using a reaction-diffusion framework (RDF) that exploits the multiscale coupling of molecular diffusion with chemical reactions, nucleation and growth of crystals. In an RDF, the hydroxide anions are allowed to diffuse into an organic gel matrix containing the salt mixture needed for the precipitation of the LDH. The chemical structure and composition of the synthesized magnesium-aluminium LDHs are determined using powder X-ray diffraction (PXRD), thermo-gravimetric analysis, differential scanning calorimetry, solid-state nuclear magnetic resonance (SSNMR), Fourier transform infrared and energy dispersive X-ray spectroscopy. This novel technique also allows the investigation of the mechanism of intercalation of some fluorescent probes, such as the neutral three-dimensional rhodamine B (RhB) and the negatively charged two-dimensional 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS), using in situ steady-state fluorescence spectroscopy. The incorporation of these organic dyes inside the interlayer region of the LDH is confirmed via fluorescence microscopy, solid-state lifetime, SSNMR and PXRD. The activation energies of intercalation of the corresponding molecules (RhB and HPTS) are computed and exhibit dependence on the geometry of the involved probe (two or three dimensions), the charge of the fluorescent molecule (anionic, cationic or neutral) and the cationic ratio of the corresponding LDH. This article is part of the themed issue 'Multiscale modelling at the physics-chemistry-biology interface'.

  13. Mechanism of hierarchical porosity development in MFI zeolites by desilication: the role of aluminium as a pore-directing agent.

    Science.gov (United States)

    Groen, Johan C; Peffer, Louk A A; Moulijn, Jacob A; Pérez-Ramírez, Javier

    2005-08-19

    The role of the concentration and the nature of aluminium in the creation of hierarchical porosity in both commercial and synthesized MFI zeolites have been investigated through controlled mesoporosity development by desilication in alkaline medium. Framework aluminium controls the process of framework silicon extraction and makes desilication selective towards intracrystalline mesopore formation. An optimal molar Si/Al ratio in the range 25-50 has been identified; this leads to an optimal mesoporosity centred around 10 nm and mesopore surface areas of up to 235 m(2) g(-1) while preserving the intrinsic crystalline and acidic properties. At lower framework Si/Al ratios the relatively high Al content inhibits Si extraction and hardly any mesopores are created, while in highly siliceous ZSM-5 unselective extraction of framework Si induces formation of large pores. The existence of framework Al sites in different T positions that are more or less susceptible to the alkaline treatment, and the occurrence of re-alumination, are tentative explanations for the remarkable behaviour of Al in the desilication process. The presence of substantial extra framework Al, obtained by steam treatment, inhibits Si extraction and related mesopore formation; this is attributed to re-alumination of the extraframework Al species during the alkaline treatment. Removal of extraframework Al species by mild oxalic acid treatment restores susceptibility to desilication, which is accompanied by formation of larger mesopores due to the enhanced Si/Al ratio in the acid-treated zeolite.

  14. Development of Al-TiC Alloys Using Powder Metallurgy as Grain Refiners for Aluminium and Its Alloys

    Directory of Open Access Journals (Sweden)

    Abdel-Nasser .M. Omran

    2014-07-01

    Full Text Available Al-Ti-C master alloys have been widely investigated for many years as grain refiner for aluminium and its alloys. In this work, the Al-Ti-C master alloys are synthesized using powder metallurgy technique through the mixing of aluminium and TiC powders with different TiC contents 3.75 (3, 5(4, 6.25(5 and 7.5(6 Wt% TiC(Wt% Ti. The mixing powders with different contents of TiC were pressed in cylinder shape. The pressed specimens were sintered from 450 oC in a tube furnace under argon atmosphere for 2 hrs. The produced alloys before and after sintering are examined using SEM, EDX and XRD. The results indicate that, the Al-TiC alloy containing fine TiC particles dispersed in all matrix was successfully prepared. The prepared Al-TiC alloys with different contents of TiC were evaluated using the KBI test mold as grain refiner for pure aluminum and its alloys. The results indicate that the prepared Al-TiC master alloy is high grain refining efficiency for pure aluminum and its alloys.

  15. Microstructural evolution of aluminium/Al–Ni–Sm glass forming alloy laminates obtained by Controlled Accumulative Roll Bonding

    Energy Technology Data Exchange (ETDEWEB)

    Anghelus, Adrian, E-mail: anghelus.adrian@yahoo.com; Avettand-Fènoël, Marie-Noëlle, E-mail: marie-noelle.avettand-fenoel@univ-lille1.fr; Cordier, Catherine, E-mail: catherine.cordier@univ-lille1.fr; Taillard, Roland, E-mail: roland.taillard@univ-lille1.fr

    2015-05-15

    Highlights: • Elaboration of a UFG material by controlled ARB of Al/glass forming alloy multilayers. • Effect of the crystalline or amorphous nature of the reinforcement on the formability. • Investigation of the thermo-mechanical stability of the metallic glass. - Abstract: The current work deals with the early steps of the unprecedented elaboration of aluminium/Al based glass forming alloy laminates by only accumulative rolling at room temperature. The Al{sub 1−(x+y)}Ni{sub x}Sm{sub y} metallic glass forming alloy was introduced either in its original amorphous state or after total crystallization. This change of atomic structure, and therefore of both thermal and thermo-mechanical stability and mechanical behaviour, is shown to govern at once the processing parameters, the uniformity of the laminates microstructure and the bond strength at the matrix-reinforcement interfaces. The potential of the process so as to synthesize composite materials with a stable ultrafine structure is finally outlined.

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

    Science.gov (United States)

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

    2015-01-01

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

  17. Aluminium in food and daily dietary intake assessment from 15 food groups in Zhejiang Province, China.

    Science.gov (United States)

    Zhang, Hexiang; Tang, Jun; Huang, Lichun; Shen, Xianghong; Zhang, Ronghua; Chen, Jiang

    2016-06-01

    Aluminium was measured in 2580 samples of 15 food groups and dietary exposure was estimated. Samples were purchased and analysed during 2010 to 2014. High aluminium levels were found in jellyfish (mean 4862 mg/kg), laver (mean 455.2 mg/kg) and fried twisted cruller (mean 392.4 mg/kg). Dietary exposure to aluminium was estimated for Zhejiang residents. The average dietary exposure to aluminium via 15 food groups in Zhejiang Province was 1.15 mg/kg bw/week, which is below the provisional tolerable weekly intake of 2 mg/kg bw /week. Jellyfish is the main Al contributor, providing 37.6% of the daily intake via these 15 food groups. This study provided new information on aluminium levels and assessment of aluminium (Al) dietary exposure in Zhejiang Province of China.

  18. Surface roughness effects on aluminium-based ultraviolet plasmonic nanolasers

    Science.gov (United States)

    Chung, Yi-Cheng; Cheng, Pi-Ju; Chou, Yu-Hsun; Chou, Bo-Tsun; Hong, Kuo-Bin; Shih, Jheng-Hong; Lin, Sheng-Di; Lu, Tien-Chang; Lin, Tzy-Rong

    2017-01-01

    We systematically investigate the effects of surface roughness on the characteristics of ultraviolet zinc oxide plasmonic nanolasers fabricated on aluminium films with two different degrees of surface roughness. We demonstrate that the effective dielectric functions of aluminium interfaces with distinct roughness can be analysed from reflectivity measurements. By considering the scattering losses, including Rayleigh scattering, electron scattering, and grain boundary scattering, we adopt the modified Drude-Lorentz model to describe the scattering effect caused by surface roughness and obtain the effective dielectric functions of different Al samples. The sample with higher surface roughness induces more electron scattering and light scattering for SPP modes, leading to a higher threshold gain for the plasmonic nanolaser. By considering the pumping efficiency, our theoretical analysis shows that diminishing the detrimental optical losses caused by the roughness of the metallic interface could effectively lower (~33.1%) the pumping threshold of the plasmonic nanolasers, which is consistent with the experimental results.

  19. Muon motion in pure and weakly doped aluminium

    CERN Document Server

    Niinikoski, T O; Karlsson, E; Kehr, K W; Norlin, L O; Richter, D; Welter, J M

    1981-01-01

    The authors have studied the diffusion and localization of positive muons in pure and weakly doped aluminium, in the temperature range 30 mK-100K, by measuring the damping parameter of the muon spin rotation ( mu SR) signal. In this paper they discuss some of their recent results and draw the following conclusions: i) in pure Al, positive muons are delocalized in band states (coherent motion); ii) in Al doped with 5-70 ppm Mn, the temperature, concentration and field dependences of the damping parameter suggest diffusion or capture limited trapping to octahedral interstitial sites in the aluminium lattice below 1K; iii) above 2K a two-state diffusion-trapping model explains well the peak in the damping parameter, which appears at 15-50K for the dopants Mn, Mg, Li and Ag so far studied. (11 refs).

  20. 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.

  1. (-) deprenyl attenuates aluminium induced neurotoxicity in primary cortical cultures.

    Science.gov (United States)

    Munirathinam, S; Lakshmana, M K; Raju, T R

    1996-06-01

    The role of (-) deprenyl in offering neuroprotection to cortical neurons exposed to Aluminium chloride (AlCl3) was examined. Primary cortical cultures derived from newborn rats were exposed to AlCl3 on 6th day in vitro, at 100,200,400,600,800 and 1000 microM concentrations of AlCl3. After 48 h of AlCl3 exposure, many nerve cell bodies were swollen; a beading of neurites and a disruption of the neuritic network were also observed suggesting neurodegeneration. Lactate dehydrogenase (LDH) efflux increased in a dose-dependent manner (59-120%). (-) Deprenyl co-exposure at concentrations of 10(-7), 10(-8) and 10(-9) M significantly attenuated both the morphological alterations and the LDH efflux induced by AlCl3. This in vitro study has demonstrated that (-) deprenyl can protect neurons from aluminium induced neurotoxicity.

  2. Persistent Skin Reactions and Aluminium Hypersensitivity Induced by Childhood Vaccines.

    Science.gov (United States)

    Salik, Elaha; Løvik, Ida; Andersen, Klaus E; Bygum, Anette

    2016-11-02

    There is increasing awareness of reactions to vaccination that include persistent skin reactions. We present here a retrospective investigation of long-lasting skin reactions and aluminium hypersensitivity in children, based on medical records and questionnaires sent to the parents. In the 10-year period 2003 to 2013 we identified 47 children with persistent skin reactions caused by childhood vaccinations. Most patients had a typical presentation of persisting pruritic subcutaneous nodules. Five children had a complex diagnostic process involving paediatricians, orthopaedics and plastic surgeons. Two patients had skin biopsies performed from their skin lesions, and 2 patients had the nodules surgically removed. Forty-two children had a patch-test performed with 2% aluminium chloride hexahydrate in petrolatum and 39 of them (92%) had a positive reaction. The persistent skin reactions were treated with potent topical corticosteroids and disappeared slowly. Although we advised families to continue vaccination of their children, one-third of parents omitted or postponed further vaccinations.

  3. Effects and mechanisms of grain refinement in aluminium alloys

    Indian Academy of Sciences (India)

    K T Kashyap; T Chandrashekar

    2001-08-01

    Grain refinement plays a crucial role in improving characteristics and properties of cast and wrought aluminium alloys. Generally Al–Ti and Al–Ti–B master alloys are added to the aluminium alloys to grain refine the solidified product. The mechanism of grain refinement is of considerable controversy in the scientific literature. The nucleant effects i.e. which particle and its characteristics nucleate -Al, has been the subject of intensive research. Lately the solute effect i.e. the effect of dissolved titanium on grain refinement, has come into forefront of grain refinement research. The present paper attempts to review the literature on the nucleant effects and solute effects on grain refinement and addresses the importance of dissolved titanium in promoting nucleation of -Al on nucleant particles.

  4. 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.

  5. High-pressure direct synthesis of aluminium nitride

    CERN Document Server

    Bockowski, M; Grzegory, I; Krukowski, S; Wróblewski, M; Porowski, S

    2002-01-01

    We report the results of direct synthesis of aluminium nitride (AlN) under high nitrogen pressure up to 1 GPa and temperatures up to 2000 K. At pressure from 10 to 650 MPa we observe the combustion synthesis of AlN. As the result of the combustion process one can obtain the AlN sintered powder or AlN/Al metal matrix composites. For N sub 2 pressure higher than 650 MPa the crystal growth of AlN from the solution of atomic nitrogen in aluminium is possible. Both needle-like and bulk AlN single crystals, up to 1 cm and 1 mm, respectively, have been obtained.

  6. Thermal Effect of Ceramic Nanofiller Aluminium Nitride on Polyethylene Properties

    Directory of Open Access Journals (Sweden)

    Omer Bin Sohail

    2012-01-01

    Full Text Available Ethylene polymerization was done to form polyethylene nano-composite with nanoaluminum nitride using zirconocene catalysts. Results show that the catalytic activity is maximum at a filler loading of 15 mg nanoaluminum nitride. Differential scanning calorimeter (DSC and X-ray diffraction (XRD results show that percentage crystallinity was also marginally higher at this amount of filler. Thermal behavior of polyethylene nanocomposites (0, 15, 30, and 45 mg was studied by DSC and thermal gravimetric analyzer (TGA. Morphology of the component with 15 mg aluminium nitride is more fibrous as compared to 0 mg aluminium nitride and higher filler loading as shown by SEM images. In order to understand combustibility behavior, tests were performed on microcalorimeter. Its results showed decrease in combustibility in polyethylene nanocomposites as the filler loading increases.

  7. 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.

  8. Prediction of the ballistic limit of an aluminium sandwich panel

    Science.gov (United States)

    Campbell, J.; De Vuyst, T.; Vignjevic, R.; Hughes, K.

    2016-08-01

    This paper presents research on modelling the impact of a 150g projectile on a 35mm thick aluminium sandwich panel. The objective of the work is a predictive modelling capability for the ballistic limit of the panel. A predictive modelling capability supports the design of capture and deorbit missions for large items of space debris such as satellites and rocket upper stages. A detailed explicit finite element model was built using the LSDYNA software and results were compared with experimental data for the projectile exit velocity to establish key parameters. The primary parameters influencing the model behaviour were the strength and failure of the aluminium face sheets and the friction between projectile and panel. The model results showed good agreement with experimental results for ogive nose projectiles, but overestimated the exit velocity for flat nose projectiles.

  9. Fabrication of anodic aluminium oxide templates on curved surfaces.

    Science.gov (United States)

    Yin, Aijun; Guico, Rodney S; Xu, Jimmy

    2007-01-24

    Aluminium anodization provides a simple and inexpensive way to obtain nanoporous templates with uniform and controllable pore diameters and periods over a wide range. Moreover, one of the interesting possibilities afforded by the anodization process is that the anodization can take place on arbitrary surfaces, such as curved surfaces, which has not yet been well studied or applied in nanofabrication. In this paper, we characterize the anodization of Al films on silicon substrates with a curved top surface. The structures of the resultant anodic aluminium oxide (AAO) films are examined by scanning electron microscopy. Unique features including cessation, bending, and branching of pore channels are observed in the curved area. Possible growth mechanisms are proposed, which can also contribute to the understanding of the self-organization mechanism in the formation of porous AAO membranes. The new structures may open new opportunities in optical, electronic and electrochemical applications.

  10. TORSIONAL DEFORMATION AND FATIGUE BEHAVIOUR OF 6061 ALUMINIUM ALLOY

    Directory of Open Access Journals (Sweden)

    marini marno

    2012-02-01

    Full Text Available Torsional deformation and fatigue behaviour of both solid and thin-walled tubular specimens were made from as-received and heat treated 6061 aluminium alloy were studied. 6061 aluminium alloy have been widely used as a candidate material in automobile, aerospace, aircraft and structural application because of their superior mechanical properties such as high strength to weight ratio, good ductility and others. The differences in cyclic deformation and fatigue behaviours between round and solid specimens where a stress gradient exist, and thin-walled tubular specimens where a uniform stress state is commonly assumed, are also discussed. Von Mises and Tresca criteria has been used to predict the monotonic and cyclic deformation curve and compared to the torsional data obtained from the experiment. The S-N curve was used to present and evaluate the fatigue life of the specimens. Through fractographic analysis, failure criteria of fracture surfaces were observed and discussed. 

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

    Directory of Open Access Journals (Sweden)

    Marija Soldo Gjeldum

    2006-01-01

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

  12. Insight into the cellular fate and toxicity of aluminium adjuvants used in clinically approved human vaccinations

    OpenAIRE

    2016-01-01

    Aluminium adjuvants remain the most widely used and effective adjuvants in vaccination and immunotherapy. Herein, the particle size distribution (PSD) of aluminium oxyhydroxide and aluminium hydroxyphosphate adjuvants was elucidated in attempt to correlate these properties with the biological responses observed post vaccination. Heightened solubility and potentially the generation of Al3+ in the lysosomal environment were positively correlated with an increase in cell mortality in vitro, pote...

  13. Intermetallic particles-induced pitting corrosion in 6061-T651 aluminium alloy

    CSIR Research Space (South Africa)

    Mutombo, K

    2011-07-01

    Full Text Available -Induced Pitting Corrosion in 6061-T651 Aluminium Alloy Kalenda Mutombo Council for Scientific and Industrial Research (CSIR), South Africa kmutombo@csir.co.za Keywords: pitting corrosion, 6061-T651 aluminium alloy, intermetallic particles, 3.5% Na... extrudability, reasonable weldability and good corrosion resistance. This alloy finds widespread application in ship building and in the fabrication of tank containers for transporting various liquids. 6061-T651 aluminium alloy is, however, prone to pitting...

  14. Inoculation of aluminium with titanium and boron addition

    Directory of Open Access Journals (Sweden)

    J. Szajnar

    2007-07-01

    Full Text Available Purpose: The main aim of studies was to determine mechanism of inocualtion of pure alumnium EN AW-Al99,5 structure with addition of titanium and boron, which are introduced to liquid metal in small ammount - less than obligatory standard PN-EN 573-3 (concerning about aluminium purity.Design/methodology/approach: To investigations it was used light microscopy, X-ray Phase Analysis and TEM. Surfaces of samples which were prepared for macrostructure analysis were etched with use of solution of: 50g Cu, 400ml HCl, 300ml HNO3 and 300ml H2O. Surfaces of samples which were were prepared for microstructure analysis were etched with use of solution of: 0,5ml HF, 99,5ml 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, that increase of size reduction in aluminium EN AW-Al99,5 after inoculation with (Ti+B result from “washers” of type Ti3Al and CuTi2 to heterogeneous nucleation formation.Research limitations/implications: I further research, authors of this paper are going to identifiy the “washers” to heterogeneous nucleation, in aluminium structure after inoculation with zirconium and vanadium addition.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.

  15. Dispersionen für den Korrosionsschutz von Aluminium

    OpenAIRE

    Henke, Axel

    2001-01-01

    The adsorption and organization of reactive microgels has been investigated on technical aluminium. By means of a two-step emulsion polymerisation with phosphate substituted monomer we obtain polymeric nano-particles with phosphate groups on the surface. In a first step cross-linked butyl acrylate/styrene particles were formed. In a second step a mixture of functionalised acrylate and butyl acrylate/styrene was added to the system. In this way, the composite particles were obtained. Particle ...

  16. Aluminium in brain tissue in familial Alzheimer’s disease

    OpenAIRE

    Mirza, A; King, A.; Troakes, C.; Exley, C

    2016-01-01

    The genetic predispositions which describe a diagnosis of familial Alzheimer’s disease can be considered as cornerstones of the amyloid cascade hypothesis. Essentially they place the expression and metabolism of the amyloid precursor protein as the main tenet of disease aetiology. However, we do not know the cause of Alzheimer’s disease and environmental factors may yet be shown to contribute towards its onset and progression. One such environmental factor is human exposure to aluminium and a...

  17. Sintering of nano crystalline silicon carbide doping with aluminium nitride

    Indian Academy of Sciences (India)

    M S Datta; A K Bandyopadhyay; B Chaudhuri

    2002-04-01

    Sinterable silicon carbide powders were prepared by attrition milling and chemical processing of an acheson type -SiC. Pressureless sintering of these powders was achieved by addition of aluminium nitride together with carbon. Nearly 99% sintered density was obtained. The mechanism of sintering was studied by scanning electron microscopy and transmission electron microscopy. This study shows that the mechanism is a solid sintering process.

  18. Estimation of Beta-Naphthol in Aluminium Soap

    Directory of Open Access Journals (Sweden)

    S. C. Ganguli

    1962-01-01

    Full Text Available A method is described for the determination of naphtha in aluminium soaps based on the Formation of dye para red by coupling the former with diazotised p-nitraniline under controlled temperature and pH and estimation of the colour developed after extraction with alcoholic NaOH. The method has been found to be reasonably accurate under the experimental conditions.

  19. The aluminium content of infant formulas remains too high

    OpenAIRE

    2013-01-01

    Background Recent research published in this journal highlighted the issue of the high content of aluminium in infant formulas. The expectation was that the findings would serve as a catalyst for manufacturers to address a significant problem of these, often necessary, components of infant nutrition. It is critically important that parents and other users have confidence in the safety of infant formulas and that they have reliable information to use in choosing a product with a lower content ...

  20. The precipitation of potassium aluminium sulphate from aqueous solution

    Science.gov (United States)

    Mullin, J. W.; Žáček, S.

    1981-06-01

    A precipitation study has been made with potassium aluminium sulphate (potash alum) produced by mixing aqueous solutions of its constituent salts. Rates of nucleation, as indicated by the induction period, were measured for both agitated and non-agitated solutions over the temperature range 15-35°C. Nucleation rates increase with increases in agitation, temperature and supersaturation, but the latter has the dominant effect, as predicted by classical nucleation theory. The temperature-dependence of the interfacial tension is evaluated.

  1. 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.

  2. Control of Microthrix parvicella by aluminium salts addition.

    Science.gov (United States)

    Durban, N; Juzan, L; Krier, J; Gillot, S

    2016-01-01

    Aluminium and iron chloride were added to a biological nutrient removal pilot plant (1,500 population equivalent) treating urban wastewater to investigate the control of Microthrix parvicella bulking and foaming by metallic salts. Monitoring plant performance over two 6-month periods showed a slight impact on the removal efficiencies. Addition of metallic salts (Me; aluminium or aluminium + iron) at a concentration of 41 mmol Me(kg MLSS·d) (MLSS: mixed liquor suspended solids) over 70 days allowed a stabilization of the diluted sludge volume index (DSVI), whereas higher dosages (94 mmol Me(kg MLSS·d) over 35 days or 137 mmol Me(kg MLSS·d) over 14 days induced a significant improvement of the settling conditions. Microscopic observations showed a compaction of biological aggregates with an embedding of filamentous bacteria into the flocs that is not specific to M. parvicella as bacteria from phylum Chloroflexi are embedded too. The quantitative polymerase chain reaction targeting M. parvicella further indicated a possible growth limitation in addition to the flocculation impact at the high dosages of metallic salts investigated. DSVI appeared to be correlated with the relative abundance of M. parvicella.

  3. The Effect of Thickness of Aluminium Films on Optical Reflectance

    Directory of Open Access Journals (Sweden)

    Robert Lugolole

    2015-01-01

    Full Text Available In Uganda and Africa at large, up to 90% of the total energy used for food preparation and water pasteurization is from fossil fuels particularly firewood and kerosene which pollute the environment, yet there is abundant solar energy throughout the year, which could also be used. Uganda is abundantly rich in clay minerals such as ball clay, kaolin, feldspar, and quartz from which ceramic substrates were developed. Aluminium films of different thicknesses were deposited on different substrates in the diffusion pump microprocessor vacuum coater (Edwards AUTO 306. The optical reflectance of the aluminium films was obtained using a spectrophotometer (SolidSpec-3700/DUV-UV-VIS-NIR at various wave lengths. The analysis of the results of the study revealed that the optical reflectance of the aluminium films was above 50% and increased with increasing film thickness and wavelength. Thus, this method can be used to produce reflector systems in the technology of solar cooking and other appliances which use solar energy.

  4. Analysis of Orthogonal Cutting of Aluminium-based Composites

    Directory of Open Access Journals (Sweden)

    P. Ravinder Reddy

    2002-10-01

    Full Text Available A turning test on aluminium-based metal-matrix composites (MMCs (aluminium-30% silicon carbide was performed with K-20 carbide tool material and wear patterns and the wear land growth rates were analysed to evaluate the wear characteristics and to classify the relationship between the physical (mechanical properties and the flank wear of cutting tools. The study was also extended to the machining aspects and the width of cuts on MMCs and the influence of various cutting parameters. The experiments were conducted to measure the temperature along the cutting tool edge using thermocouple at various cutting speeds, and depth of cuts, keeping the feed rate constant while turning with K-20 carbide cutting tool. The finite-element method was used to simulate the orthogonal cutting of aluminium-based MMCs. The heat generation at the chip-tool interface, frictional heat generation at the tool flank, and the heat generation at the work tool interface were calculated analytically and imposed as boundary conditions. The analysis of the steady-state heat transfer was carried out and the temperature distribution at cutting edge, shear zone, and interface regions have been reported.

  5. Spectroscopic diagnostics of plasma during laser processing of aluminium

    Science.gov (United States)

    Lober, R.; Mazumder, J.

    2007-10-01

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

  6. 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. Copyright © 2015 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2013-04-07

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

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

    Science.gov (United States)

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

    2011-05-13

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

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

    Science.gov (United States)

    Kumar, Anil; Dogra, Samrita; Prakash, Atish

    2009-12-28

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

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

    Directory of Open Access Journals (Sweden)

    Mei Yang

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

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

    Science.gov (United States)

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

    2011-11-01

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

  13. Aluminium nitride: from the powder to the substrate. Le nitrure d'aluminium: de la poudre au substrat

    Energy Technology Data Exchange (ETDEWEB)

    Jarrige, J. (Lab. de Ceramiques Nouvelles, Limoges (France)); Mexmain, J. (Lab. de Ceramiques Nouvelles, Limoges (France)); Oumaloul, M. (Lab. de Ceramiques Nouvelles, Limoges (France)); Bachelard, R. (CRRA ELF ATOCHEM, Pierre Benite (France)); Disson, J.P. (CRRA ELF ATOCHEM, Pierre Benite (France))

    1993-04-01

    The aluminium nitride is a material which should replace alumina or beryllia as substrate for power electronic applications. The powder, prepared by carbothermal nitridation, is dispersed in a butanone-2-ethanol azeotrop solvent with a phosphate ester. Electrical conductivity, sedimentation, viscosity have been used to determine which phenomena take place in the defloculation of the suspension. The stability of AlN suspensions is due mainly to an electrostatic mechanism, with a steric contribution. The aluminium nitride tape-casting slip has been sintered at 1850 C in a nitrogen atmosphere. Removing of the binder and plasticizer can be performed in the same oven at 650 C, due to their nature and low concentration. The thermal conductivity of the substrates has been measured and is in the 160 to 200 W/m.K range. (orig.).

  14. Frequency synthesizers concept to product

    CERN Document Server

    Chenakin, Alexander

    2011-01-01

    A frequency synthesizer is an electronic system for generating any of a range of frequencies from a single fixed oscillator. They are found in modern devices like radio receivers, mobile phones, and GPS systems. This comprehensive resource offers RF and microwave engineers a thorough overview of both well-established and recently developed frequency synthesizer design techniques. Professionals find expert guidance on all design aspects, including main architectures, key building blocks, and practical circuit implementation. Engineers learn the development process and gain a solid understanding

  15. X-Band PLL Synthesizer

    OpenAIRE

    P. Kutin; Vagner, P.

    2006-01-01

    This paper deals with design and realization of a PLL synthesizer for the microwave X−band. The synthesizer is intended for use as a local oscillator in a K−band downconverter. The design goal was to achieve very low phase noise and spurious free signal with a sufficient power level. For that purpose a low phase noise MMIC VCO was used in phase locked loop. The PLL works at half the output frequency, therefore there is a frequency doubler at the output of the PLL. The output signal ...

  16. Development of solar selective absorber layers on aluminium. Final report; Entwicklung solarselektiver Absorberschichten auf Aluminium fuer Solarkollektoren. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Hoenicke, D.; Moeller, T.; Schwarz, T.

    1998-01-31

    A new electrolytic process was developed to form solar selective layers on aluminium. In the developed process, both the formation of the alumina layer and the deposition of metals into the layer takes place in only one treatment step using a single electrolysis bath. The main step of the so called ISOC-method (impulse structured oxide ceramic) is the anodic oxidation of aluminium which was carried out by using a pulse technique at different voltages. During the anodic polarisation a thin alumina ceramic layer was formed, while the cathodic led to the metal deposition as copper and nickel. The conditions of the electrolysis were varied in order to estimate optimal parameters achieving solar selective layers with high selectivity. Furthermore, a scale-up of the lab scale apparatus to a mini plant was carried out. Finally, the corrosion resistance of the absorber layers was improved by the formation of a thin hydrophobic overlayer using a sol-gel treatment. (orig.) [Deutsch] Ein neuartiges Behandlungsverfahren zur Erzeugung von solarselektiven Absorberschichten auf Aluminium wurde entwickelt. Bei dieser elektrochemischen Behandlung wird in einem Einstufenprozess mit einem Elektrolyten durch eine Kombination von anodischer Oxidation und bipolarer Pulsbehandlung auf der Oberflaeche des Aluminiums eine impulsstrukturierte Oxidkeramik (ISOK) erzeugt. Dabei entsteht durch eine anodische Oxidation eine strukturierte Aluminiumoxidschicht. Bei der bipolaren Pulsbehandlung erfolgt dann eine Abscheidung der im ISOK-Elektrolyten befindlichen Metalle Cu und Ni auf oder in die Aluminiumoxidoberflaeche. Die ISOK-Behandlung wurde vom Labormassstab zu einem ISOK-Verfahren im Miniplant-Massstab entwickelt. Der Einfluss der elektrischen Parameter und der chemischen Zusammensetzung der ISOK-Elektrolyte wurde untersucht. Durch eine auf das ISOK-Verfahren abgestimmte Nachbehandlung, ein Tauchverfahren in einer Sol-Gel-Loesung, entsteht ein Schichtsystem mit hoher Solarselektivitaet

  17. Radiation resistance and parameters of activation of aluminium-magnesium-scandium and aluminium-magnesium-vanadium alloys under neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, L.I.; Ivanov, V.V.; Lazorenko, V.M.; Platov, Yu.M.; Tovtin, V.I.; Toropova, L.S. (A.A. Baikov Inst. of Metallurgy, Academy of Sciences, Moscow (Russia))

    1992-09-01

    Alloys Al-2.24Mg-0.223Sc-0.04Zr, Al-2.24Mg-0.12Sc-0.04Zr, and Al-2.24Mg-0.05V (at.%) annealed at 150deg C and 400deg C were irradiated at [approx equal] 70 and [approx equal] 150deg C in the SM-2 reactor. The maximum neutron fluence was 4.7x10[sup 24] m[sup -2] (E > 0.1 MeV). The tensile tests were carried out in the temperature range 20 to 350deg C. Alloy Al-2.24 Mg-0.23Sc-0.04Zr annealed at 400deg C and alloy Al-2.24Mg-0.12Sc-0.04Zr annealed at 150deg C at all test temperatures retained good mechanical properties after irradiation. The mechanisms for the radiation resistance of aluminium-scandium and aluminium-magnesium-scandium alloys are discussed. Calculations of induced radioactivity and its decay behaviour after shutdown in aluminium and Al-2.24Mg-(0.12-0.23)Sc alloys were carried out. Composition of the radionuclides in these materials after irradiation in the SM-2 reactor were also determined using a gamma-spectroscopy technique. (orig.).

  18. Human biomonitoring of aluminium after a single, controlled manual metal arc inert gas welding process of an aluminium-containing worksheet in nonwelders.

    Science.gov (United States)

    Bertram, Jens; Brand, Peter; Hartmann, Laura; Schettgen, Thomas; Kossack, Veronika; Lenz, Klaus; Purrio, Ellwyn; Reisgen, Uwe; Kraus, Thomas

    2015-10-01

    Several existing field studies evaluate aluminium welding works but no thoroughly controlled exposure scenario for welding fume has been described yet. This study provides information about the uptake and elimination of aluminium from welding fumes under controlled conditions. In the Aachen Workplace Simulation Laboratory, we are able to generate welding fumes of a defined particle mass concentration. We exposed 12, until then occupationally unexposed participants with aluminium-containing welding fumes of a metal inert gas (MIG) welding process of a total dust mass concentration of 2.5 mg/m(3) for 6 h. Room air filter samples were collected, and the aluminium concentration in air derived. Urine and plasma samples were collected directly before and after the 6-h lasting exposure, as well as after 1 and 7 days. Human biomonitoring methods were used to determine the aluminium content of the samples with high-resolution continuum source atomic absorption spectrometry. Urinary aluminium concentrations showed significant changes after exposure compared to preexposure levels (mean t(1) (0 h) 13.5 µg/L; mean t(2) (6 h) 23.5 µg/L). Plasma results showed the same pattern but pre-post comparison did not reach significance. We were able to detect a significant increase of the internal aluminium burden of a single MIG aluminium welding process in urine, while plasma failed significance. Biphasic elimination kinetic can be observed. The German BAT of 60 µg/g creatinine was not exceeded, and urinary aluminium returned nearly to baseline concentrations after 7 days.

  19. Template-synthesized opal hydrogels

    Institute of Scientific and Technical Information of China (English)

    LI Jun; JI Lijun; RONG Jianhua; YANG Zhenzhong

    2003-01-01

    Opal hydrogels could be synthesized with polymer inverse opal template. A pH responsive opal N-iso- propylacrylamide/acrylic acid copolymerized hydrogel was prepared as an example. The ordered structure and response to pH were investigated. Through the sol-gel process of tetrabutyl titanate, opal titania was obtained with the opal hydrogel template.

  20. Laboratory Syntheses of Insect Pheromones.

    Science.gov (United States)

    Cormier, Russell A.; Hoban, James N.

    1984-01-01

    Provides background information and procedures for the multi-step synthesis of tiger moth and boll weevil pheromones (sex attractants). These syntheses require several laboratory periods. The tiger moth pheromone synthesis is suitable for introductory organic chemistry while the boll weevil pheromone is recommended for an advanced laboratory…

  1. Information Retrieval for Ecological Syntheses

    Science.gov (United States)

    Bayliss, Helen R.; Beyer, Fiona R.

    2015-01-01

    Research syntheses are increasingly being conducted within the fields of ecology and environmental management. Information retrieval is crucial in any synthesis in identifying data for inclusion whilst potentially reducing biases in the dataset gathered, yet the nature of ecological information provides several challenges when compared with…

  2. Laboratory Syntheses of Insect Pheromones.

    Science.gov (United States)

    Cormier, Russell A.; Hoban, James N.

    1984-01-01

    Provides background information and procedures for the multi-step synthesis of tiger moth and boll weevil pheromones (sex attractants). These syntheses require several laboratory periods. The tiger moth pheromone synthesis is suitable for introductory organic chemistry while the boll weevil pheromone is recommended for an advanced laboratory…

  3. Effect of Microbial inoculation in combating the aluminium toxicity effect on growth of Zea mays.

    Science.gov (United States)

    Arora, P; Singh, G; Tiwari, A

    2017-07-31

    The present study is aimed at improving the aluminium tolerance in maize crop employing the potential of microbial inoculants in conferring resistance to these toxicities via production of certain chelating compounds like siderophores, exopolysachharides and organic acids. Acid soils have now-a-days become one of the key factors for limiting growth of many agriculturally important crops. Aluminium  is one of the major elements present in acid soils and is mainly responsible for toxicity in the soil. This aluminium is rapidly soluble in soil water and hence absorbed by plant roots under conditions where soil pH is below 5. This toxicity leads to severe root growth inhibition, thereby limiting the production of maize crops. It was observed that use of microbial inoculums can be helpful in elimination of these toxic compounds and prevent the inhibition of root growth . It was found that the soils contaminated with aluminium toxicity decreased the root length of maize plant significantly by 65% but Bacillus and Burkholderia inoculation increased this root length significantly by 1.4- folds and 2- folds respectively thereby combating the effect of aluminium toxicity. Aluminium concentration was found maximum in roots of plants which were grown under aluminium stress condition. But this aluminium accumulation decreased ̴ 2-folds when Burkholderia was used as seed inoculants under aluminium stress conditions. Also, at 60mM aluminium accumulation, phosphorus solubilisation in roots was found to be increased upto 30% on Burkholderia inoculation. However, Bacillus inoculation didn't show any significant difference in either of the case. Thus, the inoculation of seeds with Burkholderia isolates could prove to be a boon in sequestering aluminium toxicity in Zea mays.

  4. Investigation of optical limiting properties of Aluminium nanoparticles prepared by pulsed laser ablation in different carrier media

    Science.gov (United States)

    Kuladeep, Rajamudili; Jyothi, L.; Prakash, P.; Mayank Shekhar, S.; Durga Prasad, M.; Narayana Rao, D.

    2013-12-01

    In this communication, we carried out the systematic investigation of nonlinear absorption and scattering properties of Aluminium nanoparticles (Al NPs) in various polar and non-polar solvents. Al NPs were synthesized with pulsed Nd:YAG laser operated at 1064 nm by ablating Al target in polar and non-polar liquid environment like chloroform, chlorobenzene, toluene, benzene, and carbon tetrachloride. Synthesized Al NPs colloids of various solvents differ in appearance and UV-Vis extinction spectra exhibit absorption in the UV region. The characterization of Al NPs performed by Transmission electron microscopy (TEM) studies reveal that NPs are made up of a well crystallized Al inner part (bright zone) embedded with an amorphous metal Al shell (dark region). Growth, aggregation, and precipitation mechanisms which influence the optical properties and stability of NPs are found to be related to the dipole moment of the surrounding liquid environment. The nonlinear absorption and scattering studies are performed by open aperture Z-scan technique with 532 nm under nanosecond pulse excitation. The Z-scan measurements are fitted theoretically to estimate both two-photon absorption (TPA) and nonlinear scattering (NLS) coefficients. In polar solvents like chlorobenzene, chloroform synthesized Al NPs exhibited higher TPA, NLS coefficient values, and lower optical limiting threshold values in comparison with partially polar solvent like toluene and non-polar solvents like benzene and carbontetrachloride. These results indicate the potential use of Al NPs as a versatile optical limiting material.

  5. Graphitic nanofibres as catalyst for improving the dehydrogenation behavior of complex aluminium hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Hudson, M. Sterlin Leo; Raghubanshi, Himanshu; Pukazhselvan, D.; Srivastava, O.N. [Banaras Hindu Univ., Varnasi (India). Hydrogen Energy Center

    2010-07-01

    In the present work, we explored the catalytic effect of graphitic nanofibres (GNF) particularly of two different morphology, namely planar graphitic nanofibre (PGNF) and helical graphitic nanofibre (HGNF) for enhancement of hydrogen desorption from complex aluminium hydrides such as LiAlH{sub 4} and LiMg(AlH{sub 4}){sub 3}. We found that the catalytic activity of fibres depends mainly on its morphology. Hence helical morphology fibres possess superior catalytic activity than planar graphitic nanofibres. The desorption temperature for 8 mol% HGNF admixed LiAlH{sub 4} gets lowered from 159 C to 128 C with significantly faster kinetics. In 8 mol% HGNF admixed LiMg(AlH{sub 4}){sub 3} sample, the desorption temperature gets lowered from 105 C to {proportional_to}70 C. The activation energy calculated for the first step decomposition of LiAlH{sub 4} admixed with 8 mol% HGNF is {proportional_to}68 kJmol{sup -1}, whereas that for pristine LiAlH{sub 4} it is 107 kJ/mol. The activation energy calculated for as synthesized LiMg(AlH{sub 4}){sub 3} is {proportional_to}66 kJ/mol. Since the first step decomposition of LiMg(AlH{sub 4}){sub 3} occurs during GNF admixing, the activation energy for initial step decomposition of GNF admixed LiMg(AlH{sub 4}){sub 3} could not be estimated. (orig.)

  6. Mechanistic investigation of the reaction of epoxides with heterocumulenes catalysed by a bimetallic aluminium salen complex.

    Science.gov (United States)

    Beattie, Christopher; North, Michael

    2014-06-23

    The bimetallic aluminium(salen) complex [(Al(salen))2O] is known to catalyse the reaction between epoxides and heterocumulenes (carbon dioxide, carbon disulfide and isocyanates) leading to five-membered ring heterocycles. Despite their apparent similarities, these three reactions have very different mechanistic features, and a kinetic study of oxazolidinone synthesis combined with previous kinetic work on cyclic carbonate and cyclic dithiocarbonate synthesis showed that all three reactions follow different rate equations. An NMR study of [Al(salen)]2O and phenylisocyanate provided evidence for an interaction between them, consistent with the rate equation data. A variable-temperature kinetics study on all three reactions showed that cyclic carbonate synthesis had a lower enthalpy of activation and a more negative entropy of activation than the other two heterocycle syntheses. The kinetic study was extended to oxazolidinone synthesis catalysed by the monometallic complex Al(salen)Cl, and this reaction was found to have a much less negative entropy of activation than any reaction catalysed by [Al(salen)]2O, a result that can be explained by the partial dissociation of an oligomeric Al(salen)Cl complex. A mechanistic rationale for all of the results is presented in terms of [Al(salen)]2O being able to function as a Lewis acid and/or a Lewis base, depending upon the susceptibility of the heterocumulene to reaction with nucleophiles.

  7. Synthesis and forming behavior of aluminium-based hybrid powder metallurgic composites

    Institute of Scientific and Technical Information of China (English)

    M.Ravichandran; A. Naveen Sait; V.Anandakrishnan

    2014-01-01

    Aluminium-based metal matrix composites were synthesized from Al-TiO2-Gr powder mixtures using the powder metallurgy technique and their forming characteristics were studied during cold upsetting. Green cylindrical compacts of pure Al, Al-5wt%TiO2, Al-5wt%TiO2-2wt%Gr, and Al-5wt%TiO2-4wt%Gr were made using a 400-kN hydraulic press equipped with suitable punch and die and by sintering at (590 ± 10)°C for 3 h. Cold upset forging tests were carried out, the true axial stress (σz), the true hoop stress (σө), and the true hy-drostatic stress (σm) were evaluated and, their behavior against the true axial strain (εz) was also analyzed. It is observed that the addition of 5wt%TiO2 into the Al matrix increasesσz,σө, andσm. The addition of both TiO2 and Gr reinforcements reduces the densification and defor-mation characteristics of the sintered preforms during cold upsetting. Microstructure analyses of the as-sintered and cold upset forged speci-mens also were carried out to substantiate the experimental results.

  8. The Hamlet dilemma for aluminium cans in the circular economy: to be or not to be in a closed loop

    DEFF Research Database (Denmark)

    Niero, Monia; Boas, Simon H.; Langen, Håkon

    2015-01-01

    can recycling. We performed a Life Cycle Assessment (LCA) comparing different sources of aluminium: primary aluminium and mixed scraps, Used Beverage Can (UBC) scrap, mixed aluminium packaging scrap and building scrap. The preliminary LCA results show that the lowest environmental impacts come from...... the use of UBC scraps. This suggests that in a circular economy context for aluminium cans it is better to be in a closed loop....

  9. Enhancement of wear and ballistic resistance of armour grade AA7075 aluminium alloy using friction stir processing

    OpenAIRE

    I. Sudhakar; V. Madhu; G. Madhusudhan Reddy; K. Srinivasa Rao

    2015-01-01

    Industrial applications of aluminium and its alloys are restricted because of their poor tribological properties. Thermal spraying, laser surfacing, electron beam welding are the most widely used techniques to alter the surface morphology of base metal. Preliminary studies reveal that the coating and layering of aluminium alloys with ceramic particles enhance the ballistic resistance. Furthermore, among aluminium alloys, 7075 aluminium alloy exhibits high strength which can be compared to tha...

  10. Structural investigation of nanomixed xSnO2–Al2O3 synthesized by sol–gel route

    Directory of Open Access Journals (Sweden)

    C. Kumar

    2015-12-01

    Full Text Available Abstract Nanomixed SnO2–Al2O3 with variable composition has been synthesized by sol–gel technique using aluminium dichloride and stannous chloride as precursors. Synthesized nanocomposites have been characterized using various techniques such as X-ray diffraction (XRD, Fourier transform infrared, scanning electron microscopy and Energy-dispersive X-ray spectroscopy (EDX, Brunauer–Emmett–Teller (BET. XRD shows decrease in crystallinity as alumina component increases in following series of nanomixed oxides. The specific surface area calculated by Brunauer–Emmett–Teller (BET method was about 191 m2/g and average pore diameter of 158 Å.

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

    NARCIS (Netherlands)

    van Hulten, M. M. P.; Sterl, A.; Tagliabue, A.; Dutay, J. -C.; Gehlen, M.; de Baar, H. J. W.; Middag, R.

    2013-01-01

    A model of aluminium has been developed and implemented in an Ocean General Circulation Model (NEMO-PISCES). In the model, aluminium enters the ocean by means of dust deposition. The internal oceanic processes are described by advection, mixing and reversible scavenging. The model has been evaluated

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

    CSIR Research Space (South Africa)

    Van Hulten, M

    2013-10-01

    Full Text Available A model of aluminium has been developed and implemented in an Ocean General Circulation Model (NEMO-PISCES). In the model, aluminium enters the ocean by means of dust deposition. The internal oceanic processes are described by advection, mixing...

  13. Design of an aluminium bicycle path integrated in a steel bridge

    NARCIS (Netherlands)

    Maljaars, J.; Soetens, F.; Burggraaf, H.G.

    2007-01-01

    This paper describes the design of the aluminium structure of a bicycle path which is mounted on an existing steel brige. The benefits of aluminium, being low self weight, freedom in design obtained by extrusion and good corrosion resistance were maximal utilized. One of the main drawbacks of alumin

  14. Application of surface plasmon polaritons in the laser ablation and characterisation of thin aluminium films

    Science.gov (United States)

    Cairns, G. F.; McNeill, D. A.; Dawson, P.

    1999-06-01

    Surface modification of thin aluminium films is both produced and characterised by exciting surface plasmon polaritons in an attenuated total reflection geometry: silica prism/aluminium/ aluminium oxide system. The modification is performed, under ambient conditions, by exposure to a low fluence (pulse of radiation from an excimer laser at wavelength 248 nm. Pre- and post-ablation characterisation of samples is performed at a centre wavelength of 250 nm by using a xenon lamp and optical filtration. Modelling of the characteristic reflectance-angle curves from areas exposed to the laser shows both an increased oxide thickness and the presence of an optically absorbing cermet layer, a region of mixed metal and oxide, between the aluminium and the aluminium oxide. Analysis of the results suggests that the interfacial aluminium/oxide region supporting the surface mode is ablated by means of a non-thermal, bond-breaking mechanism leading to further surface oxide formation and a progressively less complete oxidation process for a finite distance into the aluminium film. However, the ablation is frustrated in the sense that there is little or no net loss of aluminium from the system.

  15. Influence of Alkali Treatment on the Surface Area of Aluminium Dross

    Directory of Open Access Journals (Sweden)

    N. S. Ahmad Zauzi

    2016-01-01

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

  16. The Macro-Adjustment Policies on China’s Aluminium Industry

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    <正>In recent years, China’s aluminium industry has developed rapidly with considerable expansion of the production scale. Presently, China’s aluminum production capacity has taken a quarter of the world total, and China has become the largest aluminium producer in the world, However, such large scaled expan-

  17. Neuroprotective role of Convolvulus pluricaulis on aluminium induced neurotoxicity in rat brain.

    Science.gov (United States)

    Bihaqi, Syed Waseem; Sharma, Meenakshi; Singh, Avninder Pal; Tiwari, Manisha

    2009-07-30

    Convolvulus pluricaulis (Convolvulaceae) has long been used as traditional herbal medicine in India as nerve tonic. We investigated neuroprotective effects of aqueous extract from Convolvulus pluricaulis (CP) against aluminium chloride induced neurotoxicity in rat cerebral cortex. Daily administration of CP (150 mg/kg) for 3 months along with aluminium chloride (50 mg/kg) decreased the elevated enzymatic activity of acetylcholine esterase and also inhibited the decline in Na(+)/K(+)ATPase activity which resulted from aluminium intake. Beside, preventing accumulation of lipid and protein damage, changes in the levels of endogenous antioxidant enzymes associated with aluminium administration were also rectified. Oral administration of CP preserved the mRNA levels of muscarinic receptor 1 (M1 receptor), choline acetyl transferase (ChAT) and Nerve Growth Factor-Tyrosine kinase A receptor (NGF-TrkA). It also ameliorated the upregulated protein expression of cyclin dependent kinase5 (Cdk5) induced by aluminium. The potential of CPE to inhibit aluminium induced toxicity was compared with rivastigmine tartrate (1mg/kg), which was taken as standard. The potential of the extract to prevent aluminium-induced neurotoxicity was also reflected at the microscopic level, indicative of its neuroprotective effects. Convolvulus pluricaulis possesses neuroprotective potential, thus validating its use in alleviating toxic effects of aluminium.

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    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...

  19. Microstructures of alloyed and dispersed hard particles in the aluminium surface

    CSIR Research Space (South Africa)

    Pityana, S

    2010-03-01

    Full Text Available Laser surface alloying of A1200 aluminium alloy was carried out using a 4.4 kW Nd:YAG laser. Powder mixtures of SiC and TiC hard particles were injected into the laser generated melt pool on the aluminium substrate using a commercial powder feeder...

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

    Science.gov (United States)

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

    2013-11-01

    Aluminium oxyhydroxide, Al(OH)3 is one of few compounds approved as an adjuvant in human vaccines. However, the mechanism behind its immune stimulating properties is still poorly understood. In vitro co-culture of an aluminium adjuvant and the human monocytic cell line THP-1 resulted in reduced cell proliferation. Inhibition occurred at concentrations of adjuvant several times lower than would be found at the injection site using a vaccine formulation containing an aluminium adjuvant. Based on evaluation of the mitochondrial membrane potential, THP-1 cells showed no mitochondrial rupture after co-culture with the aluminium adjuvant, instead an increase in mitochondrial activity was seen. The THP-1 cells are phagocytosing cells and after co-culture with the aluminium adjuvant the phagosomal pathway was obstructed. Primary or early phagosomes mature into phagolysosomes with an internal pH of 4.5 - 5 and carry a wide variety of hydrolysing enzymes. Co-culture with the aluminium adjuvant yielded a reduced level of acidic vesicles and cathepsin L activity, a proteolytic enzyme of the phagolysosomes, was almost completely inhibited. THP-1 cells are an appropriate in vitro model in order to investigate the mechanism behind the induction of a phagocytosing antigen presenting cell into an inflammatory cell by aluminium adjuvants. Much information will be gained by investigating the phagosomal pathway and what occurs inside the phagosomes and to elucidate the ultimate fate of phagocytosed aluminium particles. © 2013.

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

    Science.gov (United States)

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

    2013-01-01

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

  2. 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

  3. Laser surface alloying (LSA) of aluminium (AA 1200) with TiB2 for hardness improvement

    CSIR Research Space (South Africa)

    Popoola, AP

    2010-10-01

    Full Text Available The present work deals with the development of Aluminium metal matrix composite (MMC) using TiB2 reinforcement. The aim is to improve the microhardness property of the substrate. The surface of the aluminium was sand blasted to improve its laser...

  4. Insight into the cellular fate and toxicity of aluminium adjuvants used in clinically approved human vaccinations.

    Science.gov (United States)

    Mold, Matthew; Shardlow, Emma; Exley, Christopher

    2016-08-12

    Aluminium adjuvants remain the most widely used and effective adjuvants in vaccination and immunotherapy. Herein, the particle size distribution (PSD) of aluminium oxyhydroxide and aluminium hydroxyphosphate adjuvants was elucidated in attempt to correlate these properties with the biological responses observed post vaccination. Heightened solubility and potentially the generation of Al(3+) in the lysosomal environment were positively correlated with an increase in cell mortality in vitro, potentially generating a greater inflammatory response at the site of simulated injection. The cellular uptake of aluminium based adjuvants (ABAs) used in clinically approved vaccinations are compared to a commonly used experimental ABA, in an in vitro THP-1 cell model. Using lumogallion as a direct-fluorescent molecular probe for aluminium, complemented with transmission electron microscopy provides further insight into the morphology of internalised particulates, driven by the physicochemical variations of the ABAs investigated. We demonstrate that not all aluminium adjuvants are equal neither in terms of their physical properties nor their biological reactivity and potential toxicities both at the injection site and beyond. High loading of aluminium oxyhydroxide in the cytoplasm of THP-1 cells without immediate cytotoxicity might predispose this form of aluminium adjuvant to its subsequent transport throughout the body including access to the brain.

  5. Domestic Output of Aluminium Alloy Hub Surpassing 70 million in 2007

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>According to a report from the hub branch of China Association of Automobile Manufactur- ers,China has produced a total of more than 70 million aluminium alloy hubs in 2007,a year- on-year growth over 25%,while consuming over 700,000 tons of primary aluminium the whole year.

  6. 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

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

    NARCIS (Netherlands)

    van Hulten, M. M. P.; Sterl, A.; Tagliabue, A.; Dutay, J. -C.; Gehlen, M.; de Baar, H. J. W.; Middag, R.

    2013-01-01

    A model of aluminium has been developed and implemented in an Ocean General Circulation Model (NEMO-PISCES). In the model, aluminium enters the ocean by means of dust deposition. The internal oceanic processes are described by advection, mixing and reversible scavenging. The model has been evaluated

  8. Hardfacing of aluminium alloys by means of metal matrix composites produced by laser surface alloying

    CSIR Research Space (South Africa)

    Pityana, SL

    2009-06-01

    Full Text Available Metal matrix composite layers were formed on an aluminium substrate by means of laser surface alloying method. Aluminium 1200 was used as a host material and TiC particles were used as the reinforcement. The microstructure of the modified layer...

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

    Energy Technology Data Exchange (ETDEWEB)

    Le Pimpec, F.

    2004-12-13

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

  10. Insight into the cellular fate and toxicity of aluminium adjuvants used in clinically approved human vaccinations

    Science.gov (United States)

    Mold, Matthew; Shardlow, Emma; Exley, Christopher

    2016-08-01

    Aluminium adjuvants remain the most widely used and effective adjuvants in vaccination and immunotherapy. Herein, the particle size distribution (PSD) of aluminium oxyhydroxide and aluminium hydroxyphosphate adjuvants was elucidated in attempt to correlate these properties with the biological responses observed post vaccination. Heightened solubility and potentially the generation of Al3+ in the lysosomal environment were positively correlated with an increase in cell mortality in vitro, potentially generating a greater inflammatory response at the site of simulated injection. The cellular uptake of aluminium based adjuvants (ABAs) used in clinically approved vaccinations are compared to a commonly used experimental ABA, in an in vitro THP-1 cell model. Using lumogallion as a direct-fluorescent molecular probe for aluminium, complemented with transmission electron microscopy provides further insight into the morphology of internalised particulates, driven by the physicochemical variations of the ABAs investigated. We demonstrate that not all aluminium adjuvants are equal neither in terms of their physical properties nor their biological reactivity and potential toxicities both at the injection site and beyond. High loading of aluminium oxyhydroxide in the cytoplasm of THP-1 cells without immediate cytotoxicity might predispose this form of aluminium adjuvant to its subsequent transport throughout the body including access to the brain.

  11. X-Band PLL Synthesizer

    Directory of Open Access Journals (Sweden)

    P. Kutin

    2006-04-01

    Full Text Available This paper deals with design and realization of a PLL synthesizer for the microwave X−band. The synthesizer is intended for use as a local oscillator in a K−band downconverter. The design goal was to achieve very low phase noise and spurious free signal with a sufficient power level. For that purpose a low phase noise MMIC VCO was used in phase locked loop. The PLL works at half the output frequency, therefore there is a frequency doubler at the output of the PLL. The output signal from the frequency doubler is filtered by a band-pass filter and finally amplified by a single stage amplifier.

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

    Science.gov (United States)

    Kramer, Matthias F; Heath, Matthew D

    2014-07-16

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

  13. Solid phase syntheses of oligoureas

    Energy Technology Data Exchange (ETDEWEB)

    Burgess, K.; Linthicum, D.S.; Russell, D.H.; Shin, H.; Shitangkoon, A.; Totani, R.; Zhang, A.J.; Ibarzo, J. [Texas A& M Univ., College Station, TX (United States)

    1997-02-19

    Isocyanates 7 were formed from monoprotected diamines 3 or 6, which in turn can be easily prepared from commercially available N-BOC- or N-FMOC-protected amino acid derivatives. Isocyanates 7, formed in situ, could be coupled directly to a solid support functionalized with amine groups or to amino acids anchored on resins using CH{sub 2}Cl{sub 2} as solvent and an 11 h coupling time at 25 {degree}C. Such couplings afforded peptidomimetics with an N-phthaloyl group at the N-terminus. The optimal conditions identified for removal of the N-phthaloyl group were to use 60% hydrazine in DMF for 1-3 h. Several sequences of amino acids coupled to ureas (`peptidic ureas`) and of sequential urea units (`oligoureas`) were prepared via solid phase syntheses and isolated by HPLC. Partition coefficients were measured for two of these peptidomimetics, and their water solubilities were found to be similar to the corresponding peptides. A small library of 160 analogues of the YGGFL-amide sequence was prepared via Houghten`s tea bag methodology. This library was tested for binding to the anti-{beta}-endorphin monoclonal antibody. Overall, this paper describes methodology for solid phase syntheses of oligourea derivatives with side chains corresponding to some of the protein amino acids. The chemistry involved is ideal for high-throughput syntheses and screening operations. 51 refs., 3 figs., 2 tabs.

  14. Experimental Study on the Shock Absorption Performance of Combined Aluminium Honeycombs under Impact Loading

    Directory of Open Access Journals (Sweden)

    Lei Cao

    2015-01-01

    Full Text Available Shock absorption characteristics of combined aluminium honeycomb structures were studied experimentally. In the experiments, a testing platform was design to compare the shock absorption level of different honeycomb specimens quantitatively. The shock response curves of six test points mounted on the platform were recorded with acceleration sensors when the buffer was impacted by a bullet driven by high pressure gas. The maximum acceleration values in time domain and in specifically spectral domain were obtained based on spectral analysis. Comparing the data of combined aluminium honeycomb buffer and single aluminium honeycomb buffer, conclusion can be obtained that shock absorbing characteristic of combined aluminium honeycomb buffer is better. Furthermore, compression properties of three kinds of buffers were tested under quasi-static state. The energy absorption parameters were calculated. The results show suitable combined aluminium honeycomb buffer can smooth the stress and lower the energy applied to the testing platform.

  15. Low-temperature Electrodeposition of Aluminium from Lewis Acidic 1-Allyl-3-methylimidazolium Chloroaluminate Ionic Liquids

    Institute of Scientific and Technical Information of China (English)

    郑勇; 张锁江; 吕兴梅; 王倩; 左勇; 刘恋

    2012-01-01

    Lewis acidic 1-allyl-3-methylimidazolium chloroaluminate ionic liquids were used as promising electrolytes in the low-temperature electrodeposition of aluminium. Systematic studies on deposition process have been performed by cYClic voltammetry and chronoamperometry. The surface morphology and X-ray diffraction (XRD) patterns of deposits prepared at different experimental conditions were also investigated. It was shown that the nucleation density and growth rate of crystallites had a great effect on the structure of aluminium deposited. The crys- tallographic orientation of deposits was mainly influenced by temperature and current density. Smooth, dense and well adherent aluminium coatings were obtained on copper substrates at 10-25 mA.cm^-2 and 313.2-353.2 K. More- over, the current efficiency of deposition and purity of aluminium have been significantly improved, demonstrating that the ionic liquids tested have a prospectful potential in electroplating and electrorefining of aluminium.

  16. Production and some properties of Si3N4 reinforced aluminium alloy composites

    Directory of Open Access Journals (Sweden)

    Pardeep Sharma

    2015-09-01

    Full Text Available The present research work focuses on the production of aluminium (AA6082-T6 matrix composites reinforced with various weight percentage of silicon nitride particles by conventional stir casting route. The percentage of reinforcement is varied from 0 wt.% to 12 wt.% in a stage of 3%. The microstructures and mechanical properties of the fabricated aluminium matrix composites are investigated. The scanning electron microstructure images reveal the presence of Si3N4 particles in the aluminium matrix. The distribution of Si3N4 particles has also been recognized with X-ray diffraction technique. The mechanical properties such as ultimate tensile strength and hardness have improved at the cost of reduction in ductility with increase in weight percentage of silicon nitride particulates in the aluminium metal matrix. The density and porosity of the composites also show an increasing trend with increase in volume fraction of Si3N4 particles in the aluminium matrix.

  17. Simultaneous determination of aluminium and beryllium by first-derivative synchronous solid-phase spectrofluorimetry.

    Science.gov (United States)

    Capitán, F; Manzano, E; Navalón, A; Luis Vilchez, J; Capitán-Vallvey, L F

    1992-01-01

    A method for the simultaneous determination of aluminium and beryllium in mixtures by first-deravative synchronous solid-phase spectrofluorimetry has been developed. Aluminium and beryllium reacted with morin to give fluorescent complexes, which were fixed on a dextran-type resin. The fluoresnce of the resin, packed in a 1-mm silica cell, was measured directly with a solid-surface attachment. The constant wavelength difference chosen to optimize the determination was Deltalambda = lambda(em) = 75 nm. Aluminium was measured at lambda(em)lambda = 445/520 nm and beryllium at lambda(em)lambda(em) = 430/505 nm. The range of application is between 0.5 and 5.0 ng/ml for both aluminium and beryllium. The accuracy and precision of the method are reported. The method has been successfully applied to the determination of aluminium and beryllium in synthetic mixtures and natural waters.

  18. A silanol-based nanocomposite coating for protection of AA-2024 aluminium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, E.; Pavez, J.; Azocar, I.; Zagal, J.H. [Departamento de Quimica de los Materiales, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, Avenida Bernardo O' Higgins 3363, Casilla 40, Correo 33, Santiago (Chile); Zhou, X. [Corrosion and Protection Centre, School of Materials, University of Manchester, Manchester M13 9PL (United Kingdom); Melo, F. [Departamento de Fisica, Facultad de Ciencias, Universidad de Santiago de Santiago de Chile, Avenida Bernardo O' Higgins 3363, Santiago (Chile); Thompson, G.E. [Corrosion and Protection Centre, School of Materials, University of Manchester, Manchester M13 9PL (United Kingdom); Paez, M.A., E-mail: maritza.paez@usach.cl [Departamento de Quimica de los Materiales, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, Avenida Bernardo O' Higgins 3363, Casilla 40, Correo 33, Santiago (Chile)

    2011-09-01

    Highlights: {center_dot} A new silanol-based hybrid coating has been synthesized. {center_dot} The incorporation of CeO{sub 2} and ZrO{sub 2} nanoparticles into the coating greatly improves the corrosion resistance of the coated aluminium alloy. {center_dot} The effectiveness of the coating is increasingly evident for long term exposure to the sodium chloride solution. {center_dot} The silanol-based nanocomposite coatings have self-healing ability. - Abstract: A new hybrid sol-gel type film, composed of tetraethylorthosilicate (TEOS) and tetraocthylorthosilicate (TEOCS), and modified with different nanoparticle systems, has been investigated as a coating for protection of AA-2024-T3 aluminium alloy. The nanoparticle systems considered were either ZrO{sub 2} or CeO{sub 2} or their combination{sub .} The zirconia nanoparticles were prepared from a Zr (IV) propoxide sol (TPOZ), using an organic stabilizer, and the CeO{sub 2} nanoparticles were developed spontaneously after adding cerium nitrate solution to the hybrid sol. The chemical composition and the structure of the hybrid sol-gel films were examined by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The corrosion resistance of the coated AA-2024 alloy was examined by potentiodynamic polarization. The results revealed that, for short exposure times in the electrolyte, incorporation of ZrO{sub 2} or CeO{sub 2} nanoparticles in the hybrid film does not provide an increase in the corrosion resistance of the coated AA-2024 alloy. Further, the resistance was significantly reduced by increasing the nanoparticle content. Conversely, by incorporating both nanoparticles (ZrO{sub 2} and CeO{sub 2}), the corrosion resistance of the resulting hybrid films increased slightly. The behavior changed significantly when the coated alloy was exposed to the electrolyte for 5 days. The corrosion resistance of the coatings, unmodified and modified with CeO{sub 2} or Zr

  19. Outstanding inhibitive effect of colchicine on aluminium alloy 6061 corrosion

    Directory of Open Access Journals (Sweden)

    Mudigere Krishnegowda Pavithra

    2015-12-01

    Full Text Available The corrosion protection ability of colchicine (CC on Aluminium alloy 6061 (AA6061 in 3.5% NaCl medium was examined by potentiodynamic polarization, electrochemical impedance, and chronoamperometric techniques. About 99 % of protection efficiency was achieved by 2 mM concentration of CC in 3.5% NaCl solution.The adsorption of CC on AA6061 surface obeys Langmuir isotherm by following both physisorption and chemisorption mechanism. Variation in the surface morphology of inhibited and uninhibited metal samples was examined by scanning electron microscopy. 

  20. Wear characteristics of a rheocast leaded aluminium metal - metal composite

    Energy Technology Data Exchange (ETDEWEB)

    Garg, R. (Roorkee Univ. (India). Dept. of Metallurgical Engineering); Mohan, S. (Banaras Hindu Univ., Varanasi (India). Dept. of Metallurgical Engineering); Agarwala, V. (Roorkee Univ. (India). Dept. of Metallurgical Engineering); Agarwala, R.C. (Roorkee Univ. (India). Dept. of Metallurgical Engineering)

    1993-10-01

    In Al-Pb alloys, boundary lubrication is provided by lead but the matrix with pure aluminium does not provide adequate strength at high loads and high sliding velocities. So in the present investigation an Al-Cu-Si alloy has been taken as the base material and lead has been incorporated by the rheocasting technique. Wear characteristics of the alloy have been investigated at different loads, sliding velocities and sliding distances. Bulk wear has been observed to increase almost linearly with applied load and sliding velocity, but with sliding distance the bulk wear shows a short period of running-in followed by a long steady-state wear. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-06-15

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

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

    Science.gov (United States)

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

    1979-01-01

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

  3. Skin telangiectasia in workers of an aluminium processing plant.

    Science.gov (United States)

    Balić, J; Kansky, A

    1988-01-01

    Telangiectases were detected in 57 (46.7%) of 122 workers employed at the electrolysis department of the aluminium plant Lozovac/Sibenik, Yugoslavia. Of 116 workers employed in the smeltery of the same plant, telangiectases were observed in 19 persons (16.4%) and in a group of 121 public transportation workers from Sibenik 15 men (12.4%) displayed enlarged blood vessels. Statistical evaluation revealed the difference in number between workers showing telangiectases engaged in electrolysis and the other two samples to be significant. It may be assumed that telangiectases were caused by hydrogen fluoride and other fluorides. Further clinical parameters, as well as working conditions, are reviewed.

  4. Large aluminium wire spark chambers with magnetostrictive read-out

    CERN Document Server

    Bradamante, Franco; Daum, C; Dechelette, Paul; Fidecaro, Giuseppe; Fidecaro, Maria; Giorgi, M; Penzo, Aldo L; Piemontese, L; Renevey, Max; Schiavon, Paolo; Vascotto, Alessandro

    1974-01-01

    A set of 1 cm gap wire spark chambers with a sensitive surface of 300 * 100 cm/sup 2/ was constructed for an experiment at the CERN proton synchrotron. The Coulomb scattering was limited by using aluminium wires and by adopting a crossed-wire configuration, which allowed us to minimize the number of chambers for a given number of pairs of coordinates. The wire planes were pulsed by feeding the high voltage from strip-lines along the whole boundary of the chambers. (7 refs).

  5. 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...

  6. Characterisation of austempered spheroidal graphite aluminium cast iron

    Energy Technology Data Exchange (ETDEWEB)

    Boutorabi, S.M.A. [Iran Univ. of Science and Technology, Tehran (Iran, Islamic Republic of). Dept. of Metallurgy and Materials

    1997-06-01

    The micro constituents of austempered spheroidal graphite aluminium cast iron were investigated. The heat tinting, special etching and microhardness measurement techniques were used. The results showed that the colour of each micro constituents and the hardness values in austempered ductile iron depend on the carbon content of each phase. The above techniques were supported by using an special etching which showed similar differences in each phase. It was shown that the heat tinting and special etching are reliable tools to characterise the complex matrix of ADI. The microhardness data supported interestingly the colour changes in above technique. (orig.)

  7. The Adsorption of NOx on Magnesium Aluminium Hydrotalcite

    Institute of Scientific and Technical Information of China (English)

    Zhe Ming NI; Wei Hua YU; Shao Fen ZHAO; Zhong Hua GE

    2004-01-01

    Magnesium aluminium hydrotalcite (Mg-Al-HT) with molar ratio of Mg-to-Al of 3 to 1 was prepared and characterized by X-ray diffraction (XRD) and infrared spectra (IR).The performances of Mg-Al-HT for the adsorption and desorption of NOx were studied.The results indicated that the adsorption capacity of the hydrotalcite for NOx was 1398.2 mg/g, and it was higher than the acticarbon's.The adsorption capacities depended on adsorption time and temperature.Mg-Al-HT could be regenerated by thermal decomposition, and the adsorption efficiency had not changed markedly after three cycles.

  8. Spectrum Simulation of Li-Like Aluminium Plasma

    Institute of Scientific and Technical Information of China (English)

    PENG Feng; JIANG Gang; ZHU Zheng-He

    2006-01-01

    X-ray emission spectra for L-shell of Li-like aluminium ions are simulated by using the flexible atomic code based on the collisional radiative model. Atomic processes including radiative recombination, dielectronic recombination, collisional ionization and resonance excitation from the neighbouring ion (Al9+ and Al11+) charge states of the target ion (Al10+) are considered in the model. In addition, the contributions of different atomic processes to the x-ray spectrum are analysed. The results show that dielectronic recombination, radiative recombination, collisional ionization and resonance excitation, other than direct collisional excitation, are very important processes.

  9. Slowdown of the Aluminium Capacity Expansions in China

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    <正> According to a senior advisor to the ChinaNonferrous Metals Techno-Economic ResearchInstitute,the Chinese Government’s efforts onthe control over the rapid development of thealuminium industry have showed their effectswith some aluminium smelters closing down in2004 and more will follow suit in 2005.According to the advisor,although China’saluminium production scale is still rather large,the central government’s efforts made on themuch heated development of the aluminiumindustry have effectively prevented it from fur-ther growing.He believes that the primary

  10. Role of acidic chemistries in steam treatment of aluminium alloys

    DEFF Research Database (Denmark)

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

    2015-01-01

    The effect of acidic chemistry on the accelerated growth of oxide on aluminium alloys Peraluman 706TM and AA6060 under exposure to high temperature steam was investigated. Studied chemistries were based on citrates and phosphates. Results showed that the presence of citrate and phosphate anions...... initiate doxide growth at the intermetallic particles while growth and corrosion performance of oxide was found tobe a function of anions type and their concentration. Further, steam treatment with phosphates exhibited better performance under acetic acid salt spray and filiform corrosion test whereas...

  11. Release Behaviour of Shock Loaded LY12 Aluminium Alloy

    Institute of Scientific and Technical Information of China (English)

    YAN Min; DAI Lan-Hong; SHEN Le-Tian

    2005-01-01

    @@ By making use of a light gas gun, a specially designed target is impacted by the LY12 flyer, and the pressure is taken in the range of 0.6-3 GPa. Based on the stress profiles measured in the buffer materials by manganese gauges, the Hugoniot curve and release curves of LY12 aluminium alloy are obtained. Meanwhile, the release curves from different initial shocked states are described in both the pressure-particle velocity plane and the pressure-specific volume plane.

  12. Physical model of aluminium refining process in URC-7000

    Directory of Open Access Journals (Sweden)

    M. Saternus

    2009-07-01

    Full Text Available The paper presents short characteristics of the most frequently used reactors for the continuous refining of aluminium and its alloys. Refining depends on the flow rate of refining gas. It influences the shape and size of gas bubbles. So the physical model was created to determine the level of gas bubble dispersion in liquids. Schemes of gas dispersion in liquid metal were presented taking into consideration that the gas flow rate is changing from 2 to 30 dm3/min. The range selection of the flow rate of refining gas value for five patterns of the dispersion (no dispersion, minimum, intimate, uniform and overdispersion was also done.

  13. Design considerations for HFQ® hot stamped aluminium structural panels

    Directory of Open Access Journals (Sweden)

    Foster Alistair

    2015-01-01

    Full Text Available HFQ is a deep drawing process for alloyed aluminium sheet that can be used to produce complex-stamped forms while maintaining the high-strength of 6xxx and 7xxx alloys. By adopting a strategy to design for HFQ at the platform level, designers can reduce part count (thereby reducing cost and weight, reduce gauge (thereby reducing weight, and improve part packaging. Two simple design examples are given to assist designers in evolving traditionally formed panel designs to HFQ formed solutions. Example features are used to illustrate the effect of geometry, thickness and strength on the final structural component.

  14. Optically Designed Anodised Aluminium Surfaces: Microstructural and Electrochemical Aspects

    DEFF Research Database (Denmark)

    Gudla, Visweswara Chakravarthy

    under high frequency anodising, highly reflecting, bright and glossy white anodised aluminium surfaces were generated for the first time. Further, these white anodised surfaces were conventionally dyed to generate new appearances based on pastel colours. The work presented in this thesis is mainly......-13). The outcome of the work is presented in the last chapter (Chapter 15). The results from white anodising of the Al surfaces, which is the primary goal of this thesis and also the generation of a new set of pastel coloured anodised surfaces is presented. The optical characterization of these white anodised...

  15. Deviatoric Response of AN Armour-Grade Aluminium Alloy

    Science.gov (United States)

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

    2009-12-01

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

  16. Synthesized Optimization of Triangular Mesh

    Institute of Scientific and Technical Information of China (English)

    HU Wenqiang; YANG Wenyu

    2006-01-01

    Triangular mesh is often used to describe geometric object as computed model in digital manufacture, thus the mesh model with both uniform triangular shape and excellent geometric shape is expected. But in fact, the optimization of triangular shape often is contrary with that of geometric shape. In this paper, one synthesized optimizing algorithm is presented through subdividing triangles to achieve the trade-off solution between the geometric and triangular shape optimization of mesh model. The result mesh with uniform triangular shape and excellent topology are obtained.

  17. Physiologically driven avian vocal synthesizer

    Science.gov (United States)

    Sitt, Jacobo D.; Arneodo, Ezequiel M.; Goller, Franz; Mindlin, Gabriel B.

    2010-03-01

    In this work, we build an electronic syrinx, i.e., a programmable electronic device capable of integrating biomechanical model equations for the avian vocal organ in order to synthesize song. This vocal prosthesis is controlled by the bird’s neural instructions to respiratory and the syringeal motor systems, thus opening great potential for studying motor control and its modification by sensory feedback mechanisms. Furthermore, a well-functioning subject-controlled vocal prosthesis can lay the foundation for similar devices in humans and thus provide directly health-related data and procedures.

  18. Method of synthesizing tungsten nanoparticles

    Science.gov (United States)

    Thoma, Steven G; Anderson, Travis M

    2013-02-12

    A method to synthesize tungsten nanoparticles has been developed that enables synthesis of nanometer-scale, monodisperse particles that can be stabilized only by tetrahydrofuran. The method can be used at room temperature, is scalable, and the product concentrated by standard means. Since no additives or stabilizing surfactants are required, this method is particularly well suited for producing tungsten nanoparticles for dispersion in polymers. If complete dispersion is achieved due to the size of the nanoparticles, then the optical properties of the polymer can be largely maintained.

  19. Downscaled anodic oxidation process for aluminium in oxalic acid

    Science.gov (United States)

    Sieber, M.; Morgenstern, R.; Kuhn, D.; Hackert-Oschätzchen, M.; Schubert, A.; Lampke, T.

    2017-03-01

    The increasing multi-functionality of parts and assemblies in several fields of engineering demands, amongst others, highly functionalised surfaces. For the different applications, on the one hand, there is a need to scale up surface modification processes originating in the nano- and micro-scale. On the other hand, conventional macro-scale surface refinement methods offer a huge potential for application in the said nano- and micro-scale. The anodic oxidation process, which is established especially for aluminium and its alloys, allows the formation of oxide ceramic layers on the surface. The build-up of an oxide ceramic coating comes along with altered chemical, tribological and electrical surface properties. As a basis for further investigations regarding the use of the anodic oxidation process for micro-scale-manufacturing, the scale effects of oxalic acid anodising on commercially pure aluminium as well as on the AlZn5.5MgCu alloy are addressed in the present work. The focus is on the amount of oxide formed during a potentiostatic process in relation to the exchanged amount of charge. Further, the hardness of the coating as an integral measure to assess the porous oxide structure is approached by nano-indentation technique.

  20. Experimental study of friction in aluminium bolted joints

    Science.gov (United States)

    Croccolo, D.; de Agostinis, M.; Vincenzi, N.

    2010-06-01

    This study aims at developing an experimental tool useful to define accurately the friction coefficients in bolted joints and, therefore, at relating precisely the tightening torque to the bolt preloading force in some special components used in front motorbike suspensions. The components under investigation are some clamped joints made of aluminium alloy. The preloading force is achieved by applying a torque wrench to the bolt head. Some specific specimens have been appropriately designed and realized in order to study the tribological aspects of the tightening phase. Experimental tests have been performed by applying the Design of Experiment (DOE) method in order to obtain a mathematical model for the friction coefficients. Three replicas of a full factorial DOE at two levels for each variable have been carried out. The levels include cast versus forged aluminium alloy, anodized versus spray-painted surface, lubricated versus unlubricated screw, and first tightening (fresh unspoiled surfaces) versus sixth tightening (spoiled surfaces). The study considers M8x1.25 8.8 galvanized screws.

  1. Geopolymerisation of fly ashes with waste aluminium anodising etching solutions.

    Science.gov (United States)

    Ogundiran, M B; Nugteren, H W; Witkamp, G J

    2016-10-01

    Combined management of coal combustion fly ash and waste aluminium anodising etching solutions using geopolymerisation presents economic and environmental benefits. The possibility of using waste aluminium anodising etching solution (AES) as activator to produce fly ash geopolymers in place of the commonly used silicate solutions was explored in this study. Geopolymerisation capacities of five European fly ashes with AES and the leaching of elements from their corresponding geopolymers were studied. Conventional commercial potassium silicate activator-based geopolymers were used as a reference. The geopolymers produced were subjected to physical, mechanical and leaching tests. The leaching of elements was tested on 28 days cured and crushed geopolymers using NEN 12457-4, NEN 7375, SPLP and TCLP leaching tests. After 28 days ambient curing, the geopolymers based on the etching solution activator showed compressive strength values between 51 and 84 MPa, whereas the commercial potassium silicate based geopolymers gave compressive strength values between 89 and 115 MPa. Based on the regulatory limits currently associated with the used leaching tests, all except one of the produced geopolymers (with above threshold leaching of As and Se) passed the recommended limits. The AES-geopolymer geopolymers demonstrated excellent compressive strength, although less than geopolymers made from commercial activator. Additionally, they demonstrated low element leaching potentials and therefore can be suitable for use in construction works. Copyright © 2016. Published by Elsevier Ltd.

  2. Aluminium surface treatment with ceramic phases using diode laser

    Science.gov (United States)

    Labisz, K.; Tański, T.; Brytan, Z.; Pakieła, W.; Wiśniowski, M.

    2016-07-01

    Ceramic particles powder feeding into surface layer of engineering metal alloy is a well-known and widely used technique. New approach into the topic is to obtain finely distributed nano-sized particles involved in the aluminium matrix using the traditional laser technology. In this paper are presented results of microstructure investigation of cast aluminium-silicon-copper alloys surface layer after heat treatment and alloying with ceramic carbides of WC and ZrO2 using high-power diode laser. The surface layer was specially prepared for the reason of reducing the reflectivity, which is the main problem in the up-to-date metal matrix composites production. With scanning electron microscopy, it was possible to determine the deformation process and distribution of WC and ZrO2 ceramic powder phase. Structure of the surface after laser treatment changes, revealing three zones—remelting zone, heat-affected zone and transition zone placed over the Al substrate. The structural changes of ceramic powder, its distribution and morphology as well as microstructure of the matrix material influence on functional properties, especially wear resistance and hardness of the achieved layer, were investigated.

  3. Aluminium-oxide wires for superconducting high kinetic inductance circuits

    Science.gov (United States)

    Rotzinger, H.; Skacel, S. T.; Pfirrmann, M.; Voss, J. N.; Münzberg, J.; Probst, S.; Bushev, P.; Weides, M. P.; Ustinov, A. V.; Mooij, J. E.

    2017-02-01

    We investigate thin films of conducting aluminium-oxide, also known as granular aluminium, as a material for superconducting high quality, high kinetic inductance circuits. The films are deposited by an optimised reactive DC magnetron sputter process and characterised using microwave measurement techniques at milli-Kelvin temperatures. We show that, by precise control of the reactive sputter conditions, a high room temperature sheet resistance and therefore high kinetic inductance at low temperatures can be obtained. For a coplanar waveguide resonator with 1.5 kΩ sheet resistance and a kinetic inductance fraction close to unity, we measure a quality factor in the order of 700 000 at 20 mK. Furthermore, we observe a sheet resistance reduction by gentle heat treatment in air. This behaviour is exploited to study the kinetic inductance change using the microwave response of a coplanar wave guide resonator. We find the correlation between the kinetic inductance and the sheet resistance to be in good agreement with theoretical expectations.

  4. Controlling interferometric properties of nanoporous anodic aluminium oxide.

    Science.gov (United States)

    Kumeria, Tushar; Losic, Dusan

    2012-01-26

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

  5. Experimental study of aluminium honeycomb behaviour under dynamic multiaxial loading

    Directory of Open Access Journals (Sweden)

    Markiewicz E.

    2012-08-01

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

  6. A 3D printed superconducting aluminium microwave cavity

    Science.gov (United States)

    Creedon, Daniel L.; Goryachev, Maxim; Kostylev, Nikita; Sercombe, Timothy B.; Tobar, Michael E.

    2016-07-01

    3D printing of plastics, ceramics, and metals has existed for several decades and has revolutionized many areas of manufacturing and science. Printing of metals, in particular, has found a number of applications in fields as diverse as customized medical implants, jet engine bearings, and rapid prototyping in the automotive industry. Although many techniques are used for 3D printing metals, they commonly rely on computer controlled melting or sintering of a metal alloy powder using a laser or electron beam. The mechanical properties of parts produced in such a way have been well studied, but little attention has been paid to their electrical properties. Here we show that a microwave cavity (resonant frequencies 9.9 and 11.2 GHz) 3D printed using an Al-12Si alloy exhibits superconductivity when cooled below the critical temperature of aluminium (1.2 K), with a performance comparable with the common 6061 alloy of aluminium. Superconducting cavities find application in numerous areas of physics, from particle accelerators to cavity quantum electrodynamics experiments. The result is achieved even with a very large concentration of non-superconducting silicon in the alloy of 12.18%, compared with Al-6061, which has between 0.4% and 0.8%. Our results may pave the way for the possibility of 3D printing superconducting cavity configurations that are otherwise impossible to machine.

  7. Cancellous bone homograft storage with aluminium-polyethylene bags.

    Science.gov (United States)

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

    2006-01-01

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

  8. A 3D Printed Superconducting Aluminium Microwave Cavity

    CERN Document Server

    Creedon, Daniel L; Kostylev, Nikita; Sercombe, Tim; Tobar, Michael E

    2016-01-01

    3D printing of plastics, ceramics, and metals has existed for several decades and has revolutionized many areas of manufacturing and science. Printing of metals in particular has found a number of novel applications in fields as diverse as customized medical implants, jet engine bearings, and rapid prototyping in the automotive industry. Whilst many techniques can be used for 3D printing metals, they commonly rely on computer controlled melting or sintering of a metal alloy powder using a laser or electron beam. The mechanical properties of parts produced in such a way have been well studied, but little attention has been paid to their electrical properties. Here we show that a resonant microwave cavity 3D printed using an Al-12Si alloy exhibits superconductivity when cooled below the critical temperature of aluminium (1.2 K), with a performance comparable to the common 6061 alloy of aluminium. Superconducting cavities find application in numerous areas of physics, from particle accelerators to cavity quantum...

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

    Science.gov (United States)

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

    2015-11-01

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

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

    Science.gov (United States)

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

    2017-06-01

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

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

    Science.gov (United States)

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

    2015-01-01

    Metal risk assessment of industrialized harbors and coastal marine waters requires the application of robust water quality guidelines to determine the likelihood of biological impacts. Currently there is no such guideline available for aluminium in marine waters. A water quality guideline of 24 µg total Al/L has been developed for aluminium in marine waters based on chronic 10% inhibition or effect concentrations (IC10 or EC10) and no-observed-effect concentrations (NOECs) from 11 species (2 literature values and 9 species tested including temperate and tropical species) representing 6 taxonomic groups. The 3 most sensitive species tested were a diatom Ceratoneis closterium (formerly Nitzschia closterium; IC10 = 18 µg Al/L, 72-h growth rate inhibition) aluminium forms of aluminate (Al(OH4 (-) ) and aluminium hydroxide (Al(OH)3 (0) ) although both dissolved, and particulate aluminium contributed to toxicity in the diatom Minutocellus polymorphus and green alga Dunaliella tertiolecta. In contrast, aluminium toxicity to the green flagellate alga Tetraselmis sp. was the result of particulate aluminium only. Four species, a brown macroalga (Hormosira banksii), sea urchin embryo (Heliocidaris tuberculata), and 2 juvenile fish species (Lates calcarifer and Acanthochromis polyacanthus), were not adversely affected at the highest test concentration used. © 2014 SETAC.

  12. Continuous flow analysis method for determination of soluble iron and aluminium in ice cores.

    Science.gov (United States)

    Spolaor, A; Vallelonga, P; Gabrieli, J; Roman, M; Barbante, C

    2013-01-01

    Iron and aluminium are the two most abundant metals on the Earth's crust, but they display quite different biogeochemical properties. While iron is essential to many biological processes, aluminium has not been found to have any biological function at all. In environmental studies, iron has been studied in detail for its limiting role in the bioproductivity of high nutrient, low carbon oceanic zones, while aluminium is routinely used as a reference of crustal contributions to atmospheric deposition archives including peat bogs, lacustrine and marine sediments and ice sheets and glaciers. We report here the development of a flow injection analysis technique, which has been optimised for the simultaneous determination of soluble iron and aluminium in polar ice cores. Iron was determined by its catalytic role in the reduction of N,N-dimethyl-p-phenylenediamene (DPD) to a semiquinonic form (DPDQ) and subsequent absorption spectroscopy at 514 nm. Aluminium was determined by spectroscopic analysis of an aluminium-lumogallion complex that exhibits fluorescence at 560 nm. These techniques have been applied to a section of Greenland ice dated to 1729-1733 AD and indicate that volcanism is a source of highly soluble aluminium and iron.

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

    Science.gov (United States)

    Exley, Christopher

    2014-01-20

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

  14. Aluminium exposure from parenteral nutrition in preterm infants and later health outcomes during childhood and adolescence.

    Science.gov (United States)

    Fewtrell, Mary S; Edmonds, Caroline J; Isaacs, Elizabeth; Bishop, Nick J; Lucas, Alan

    2011-08-01

    Aluminium is the most common metallic element, but has no known biological role. It accumulates in the body when protective gastrointestinal mechanisms are bypassed, renal function is impaired, or exposure is high - all of which apply frequently to preterm infants. Recognised clinical manifestations of aluminium toxicity include dementia, anaemia and bone disease. Parenteral nutrition (PN) solutions are liable to contamination with aluminium, particularly from acidic solutions in glass vials, notably calcium gluconate. When fed parenterally, infants retain >75% of the aluminium, with high serum, urine and tissue levels. Later health effects of neonatal intravenous aluminium exposure were investigated in a randomised trial comparing standard PN solutions with solutions specially sourced for low aluminium content. Preterm infants exposed for >10 d to standard solutions had impaired neurologic development at 18 months. At 13-15 years, subjects randomised to standard PN had lower lumbar spine bone mass; and, in non-randomised analyses, those with neonatal aluminium intake above the median had lower hip bone mass. Given the sizeable number of infants undergoing intensive care and still exposed to aluminium via PN, these findings have contemporary relevance. Until recently, little progress had been made on reducing aluminium exposure, and meeting Food and Drug Administration recommendations (<5 μg/kg per d) has been impossible in patients <50 kg using available products. Recent advice from the UK Medicines and Healthcare regulatory Authority that calcium gluconate in small volume glass containers should not be used for repeated treatment in children <18 years, including preparation of PN, is an important step towards addressing this problem.

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

    Science.gov (United States)

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

    2016-11-01

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

  16. Effective Production of Sorbitol and Mannitol from Sugars Catalyzed by Ni Nanoparticles Supported on Aluminium Hydroxide

    OpenAIRE

    Rodiansono Rodiansono; Shimazu Shogo

    2013-01-01

    Effective production of hexitols (sorbitol and mannitol) was achieved from sugars by means of nickel nanoparticles supported on aluminium hydroxide (NiNPs/AlOH) catalyst. NiNPs/AlOH catalyst was prepared by a simple and benign environmentally procedure using less amount of sodium hydroxide. ICP-AES and XRD analyses confirmed that the NiNPs/AlOH catalysts comprised a large amount of remained aluminium hydroxide (i.e. bayerite and gibbsite). The presence of aluminium hydroxide caused a high dis...

  17. The Major Events of China’s Aluminium Industry in 2005

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    <正>The year 2005 is seen as a turning point for China’s aluminium industry with the whole industry making losses leading to the closures, reorganization and acquisitions of the smelters. The macro-adjustment policies of the government on the aluminium industry and the industry’s operating difficulties led to the overall change of the industry, which is reflected by the strengthened position of China’s aluminium industry in the world and China’s influence on the world market is growing with the united

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

    Science.gov (United States)

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

    2013-10-01

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

  19. Advanced rechargeable aluminium ion battery with a high-quality natural graphite cathode

    OpenAIRE

    Wang, Di-Yan; Wei, Chuan-yu; Lin, Meng-Chang; Pan, Chun-Jern; Chou, Hung-Lung; Chen, Hsin-An; Gong, Ming; Wu, Yingpeng; Yuan, Chunze; Angell, Michael; Hsieh, Yu-Ju; Chen, Yu-Hsun; Wen, Cheng-Yen; Chen, Chun-Wei; Hwang, Bing-Joe

    2017-01-01

    Recently, interest in aluminium ion batteries with aluminium anodes, graphite cathodes and ionic liquid electrolytes has increased; however, much remains to be done to increase the cathode capacity and to understand details of the anion–graphite intercalation mechanism. Here, an aluminium ion battery cell made using pristine natural graphite flakes achieves a specific capacity of ∼110 mAh g−1 with Coulombic efficiency ∼98%, at a current density of 99 mA g−1 (0.9 C) with clear discharge voltag...

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

    Energy Technology Data Exchange (ETDEWEB)

    Bonetto, Rita [Centro de Investigacion y Desarrollo en Ciencias Aplicadas Dr. Jorge Ronco, Calle 47 No. 257, CC 59, 1900 La Plata (Argentina) and Consejo Nacional de Investigaciones Cientificas y Tecnicas de la Republica Argentina (Argentina)]. E-mail: bonetto@quimica.unlp.edu.ar; Trincavelli, Jorge [Facultad de Matematica, Astronomia y Fisica, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000, Cordoba (Argentina) and Consejo Nacional de Investigaciones Cientificas y Tecnicas de la Republica Argentina (Argentina)]. E-mail: jorge@quechua.fis.uncor.edu; Vasconcellos, Marcos [Instituto de Fisica, Universidade Federal de Rio Grande do Sul, Campus do Vale, Av. Bento Goncalves 9500, CEP: 91501-970, Porto Alegre (Brazil)]. E-mail: marcos@if.ufrgs.br

    2005-11-15

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