Shao LH  Ruther M  Linden S  Essig S  Busch K  Weissmüller J  Wegener M 《Advanced materials (Deerfield Beach, Fla.)》2010,22(45):5173-5177

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Esther Asensio  Cristina Nerín 《Packaging Technology and Science》2009,22(6):311-322

This paper deals with the study of volatile compounds released by recycled paper and board. The aim of the study was to demonstrate the feasibility of headspace procedure coupled to gas chromatography/mass spectrometry (GC/MS) applied to complex paper‐based samples together with a chemometric procedure as a powerful method for screening potential volatile contaminants released by the recycled and virgin paper samples. Using this procedure, the identification of virgin or recycled paper could be achieved based on the identification on specific markers of the recycled pulp. Fifteen different samples within virgin and recycled paper were studied. After equilibration, the vapour phase of the samples was analysed by automatic headspace coupled online to GC/MS. The analytical approach for volatile compounds, their identification and the selection of some compounds as markers for recycled pulp are shown and discussed. A discriminate analysis applied to the set of results obtained allows classification of the samples into four different groups according to the content of recycled pulp (0, 10–30 and > 80% of recycled pulp), the surface treatment of the paper (no surface treatment, clay coating and plastic coating), the grammage (from < 100 to > 300 g/m²) and the sample thickness (from < 300 to > 600 µm). The matrix effect on the volatilization of some compounds from the paper samples and the analytical behaviour are also discussed. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

    

G. Çam  S. Güçlüer  A. Çakan  H.T. Serindag 《Materialwissenschaft und Werkstofftechnik》2009,40(8):638-642

Al‐5086 H32 plates with a thickness of 3 mm were friction stir butt‐welded using different welding speeds at a tool rotational speed of 1600 rpm. The effect of welding speed on the weld performance of the joints was investigated by conducting optical microscopy, microhardness measurements and mechanical tests (i.e. tensile and bend tests). The effect of heat input during friction stir welding on the microstructure, and thus mechanical properties, of cold‐rolled Al‐ 5086 plates was also determined. The experimental results indicated that the maximum tensile strength of the joints, which is about 75 % that of the base plate, was obtained with a traverse speed of 200 mm/min at the tool rotational speed used, e.g. 1600 rpm, and the maximum bending angle of the joints can reach 180^o. The maximum ductility performance of the joints was, on the other hand, relatively low, e.g. about 20 %. These results are not unexpected due to the loss of the cold‐work strengthening in the weld region as a result of the heat input during welding, and thus the confined plasticity within the stirred zone owing to strength undermatching. Higher joint performances can also be achieved by increasing the penetration depth of the stirring probe in butt‐friction stir welding of Al‐5086 H32 plates.  相似文献   

    

J. E. Tarancón  A. Vercher  E. Giner  F. J. Fuenmayor 《International journal for numerical methods in engineering》2009,77(1):126-148

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Christina Brandenberger  Christian Mühlfeld  Zulqurnain Ali  Anke‐Gabriele Lenz  Otmar Schmid  Wolfgang J. Parak  Peter Gehr  Barbara Rothen‐Rutishauser 《Small (Weinheim an der Bergstrasse, Germany)》2010,6(15):1669-1678

This study addresses the cellular uptake and intracellular trafficking of 15‐nm gold nanoparticles (NPs), either plain (i.e., stabilized with citrate) or coated with polyethylene glycol (PEG), exposed to human alveolar epithelial cells (A549) at the air–liquid interface for 1, 4, and 24 h. Quantitative analysis by stereology on transmission electron microscopy images reveals a significant, nonrandom intracellular distribution for both NP types. No particles are observed in the nucleus, mitochondria, endoplasmic reticulum, or golgi. The cytosol is not a preferred cellular compartment for both NP types, although significantly more PEG‐coated than citrate‐stabilized NPs are present there. The preferred particle localizations are vesicles of different sizes (<150, 150–1000, >1000 nm). This is observed for both NP types and indicates a predominant uptake by endocytosis. Subsequent inhibition of caveolin‐ and clathrin‐mediated endocytosis by methyl‐β‐cyclodextrin (MβCD) results in a significant reduction of intracellular NPs. The inhibition, however, is more pronounced for PEG‐coated than citrate‐stabilized NPs. The latter are mostly found in larger vesicles; therefore, they are potentially taken up by macropinocytosis, which is not inhibited by MβCD. With prolonged exposure times, both NPs are preferentially localized in larger‐sized intracellular vesicles such as lysosomes, thus indicating intracellular particle trafficking. This quantitative evaluation reveals that NP surface coatings modulate endocytotic uptake pathways and cellular NP trafficking. Other nonendocytotic entry mechanisms are found to be involved as well, as indicated by localization of a minority of PEG‐coated NPs in the cytosol.  相似文献   

    

B. Rammer Dipl.‐Ing.  T. Weber  M. Schütze 《Materialwissenschaft und Werkstofftechnik》2008,39(1):29-32

Development of diffusion coatings on nickel base alloys for the use in chlorine‐containing high temperature processes To open up the possibility of using sewage sludge ashes as fertilizers the removal of their heavy metal contents is obligatory. A process newly developed at the BAM Berlin executes this separation in highly chlorine‐containing atmospheres at temperatures of up to 1000 °C [1]. Unfortunately there are no materials available which can withstand such conditions over longer periods of time. This project deals with the development of materials that allow the operation in highly corrosive environments. The corrosion resistance of nickel base alloys against chlorine‐induced high‐temperature corrosion will be optimized by application of aluminum‐ and/or silicon‐containing diffusion coatings. As coating method the pack cementation process was selected. In this process, the metal to be coated is embedded in a powder, consisting of the coating metal, a halogen‐distributor (e.g. ammonium chloride) and aluminum oxide as filler material. During an annealing process of several hours at temperatures of 800 to 1000 °C, gaseous metal halides form. They diffuse through the powder pack and decompose at the substrate surface, thereby depositing the coating metal. Subsequent solid phase diffusion results in the formation of a protective diffusion layer. From the thermodynamic point of view, materials with a high content of aluminum and silicon show best prerequisites to build up slow‐growing, stable oxide layers with a high potential to protect the material against corrosive attacks. The actual performance of the materials will be examined in long‐time tests under simulated field conditions (high temperatures and chlorine‐containing atmospheres).  相似文献   

    

O‐P. Kwon  S.‐J. Kwon  H. Figi  M. Jazbinsek  P. Günter 《Advanced materials (Deerfield Beach, Fla.)》2008,20(3):543-545

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Antonio Tricoli  Markus Graf  Felix Mayer  Stéphane Kuühne  Andreas Hierlemann  Sotiris E. Pratsinis 《Advanced materials (Deerfield Beach, Fla.)》2008,20(16):3005-3010

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Linjie Zhi  Yong‐Sheng Hu  Bassem El Hamaoui  Xuan Wang  Ingo Lieberwirth  Ute Kolb  Joachim Maier  Klaus Müllen 《Advanced materials (Deerfield Beach, Fla.)》2008,20(9):1727-1731

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Franck Camerel  Joaquín Barberá  Joe Otsuki  Tsubasa Tokimoto  Yuko Shimazaki  Li‐Yin Chen  Su‐Hao Liu  Ming‐Shiang Lin  Chung‐Chih Wu  Raymond Ziessel 《Advanced materials (Deerfield Beach, Fla.)》2008,20(18):3462-3467

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