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- ItemTemperature sensitivity of decomposition in relation to soil organic matter pools: Critique and outlook(Göttingen : Copernicus GmbH, 2005) Reichstein, M.; Kätterer, T.; Andrén, O.; Ciais, P.; Schulze, E.-D.; Cramer, W.; Papale, D.; Valentini, R.Knorr et al. (2005) concluded that soil organic carbon pools with longer turnover times are more sensitive to temperature. We show that this conclusion is equivocal, largely dependent on their specific selection of data and does not persist when the data set of Kätterer et al. (1998) is analysed in a more appropriate way. Further, we analyse how statistical properties of the model parameters may interfere with correlative analyses that relate the Q 10 of soil respiration with the basal rate, where the latter is taken as a proxy for soil organic matter quality. We demonstrate that negative parameter correlations between Qio-values and base respiration rates are statistically expected and not necessarily provide evidence for a higher temperature sensitivity of low quality soil organic matter. Consequently, we propose it is premature to conclude that stable soil carbon is more sensitive to temperature than labile carbon.
- ItemProdukthaftung in der Apotheke(Stuttgart : Deutscher Apotheker Verlag, 2005) Diebold, Steffen M.Stellt ein Apotheker Arzneimittel, Medizinprodukte oder andere apothekenübliche Waren (z.B. Kosmetika oder Mixturen nach Angaben von Heilpraktikern, Homöopathen oder Anthroposophen) in seiner Offizin selbst her, so haftet er (grundsätzlich) einem dadurch ggf. geschädigten Kunden (auch) nach den Vorschriften des Produkthaftungsgesetzes. Diese Haftung besteht unabhängig vom eigenen Verschulden. Sie greift auch bei der Einfuhr von Arzneimitteln aus Staaten, die nicht zum Europäischen Wirtschaftsraum gehören, sowie bei Import und Abgabe von aus Drittländern eingeführten und im Geltungsbereich des Arzneimittelgesetzes (AMG) nicht zugelassenen Fertigarzneimitteln nach § 73 (3) AMG.
- ItemPyrimidine acyclo-C-nucleosides by ring transformations of 2-formyl-L-arabinal(Basel : MDPI, 2005) Bari, A.; Feist, H.; Michalik, M.; Peseke, K.The protected 2-formyl-L-arabinal 2 reacted with thiourea and cyanamide in the presence of sodium hydride to afford via ring transformations the 5-[1R,2S-1,2-bis(benzyloxy)-3-hydroxypropyl]-1,2-dihydropyrimidines 3 and 4, respectively. Similarly, treatment of 2 with 3-amino-2H-1,2,4-triazole yielded 6-[1R,25-1,2-bis(benzyloxy)-3-hydroxypropyl][1,2,4]-triazolo[1,5-a]pyrimidine(5) .
- ItemCalculations on the dimensioning of plunger cell and feeder head(Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 2005) Reeßing, Friedrich; Schötz, Eberhard[no abstract available]
- ItemTime resolved fluorescence measurements on Tb3+ and Mn2+ doped glasses(Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 2005) Herrmann, Andreas; Ehrt, DorisTb3+ (4f8) and Mn2+ (3d5) ions, known as active luminescent centres for blue, green and red fluorescence, were doped in various fluoride, phosphate and Silicate glasses with well known structure. Narrow bands of f-f transitions with strong emission of Tb3+ in the blue, green and red and broad bands of d-d transitions of Mn2+ were measured with green emission in high optical basicity glasses with tetrahedrally coordinated Mn2+. Orange to red Mn2+ emission was found in glasses with low optical basicity where Mn2+ is octahedrally coordinated. Lifetimes, τe, in the range of milliseconds were recorded in dependence of glass composition and dopant concentration for both Tb3+ and Mn2+ doped glasses. Fluorescence lifetimes are as well shortened by higher basicity of the glasses as by increasing dopant concentration.
- ItemPreparation and properties of model glasses of historic enamels of the Green Vault Museum, Dresden(Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 2005) Wagner, Marcel; Frischat, Günther Heinz; Hellmold, PeterMany enamelled art objects of the Green Vauk Museum, Dresden, have been suffering a severe deterioration of the enamel layers during the last 20 to 30 years. The authors obtained three splinters of about 200 mg weight each of green, blue, and opaque turquoise enamel of the Aurangzeb ensemble. Model glasses of these originals were prepared which should match them as closely as possible. The investigations showed that the simple degree of network polymerization related to the SiO2/Na2O ratio is insufficient to understand their chemical properties even if one takes components such as MgO, CaO or AI2O3 also into consideration. To understand further structural influences IR, UV/VIS, and EPR spectroscopy studies were performed on the enamels, and it could be evidenced that components such as MnO, Fe2O3, CuO, CoO, PbO and SnO2 not only act as colorants or opacifiers but also as stabilizers of these materials. Taking this into account the chemical and physical behavior of the respective enamels in the museum can be elucidated.
- ItemSilicon in container glasses, its solution kinetics and dissolving potential in container glass furnaces(Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 2005) Pitzel, Christian; Stachel, Dörte; Ehrig, ReinerThe forming proeess of sihcon stones in differently colored container glasses under the action of different aluminum pieces will be discussed and some special features during the generation reported. The dissolution of formed silicon stones was analyzed in dependence on melting time, temperature and color of the glass. With the knowledge of these parameters the rate constant and the diffusion coefficient of the dissoludon were calculated. The main results are: first, it is not possible to generate large silicon stones anyway, indicated by big aluminum pieces which will be divided when they become liquid. Second, the dissolving of the silicon stones does not go on homogenously about the whole temperature range analyzed. But it can be divided into three fields: an area below, an area around and an area above the melting point of the silicon. The reason for these differences is found in the SiO2-rich layer around the stones which will be formed and dissolved by different rates in colored container glasses. On the basis of these dissolving rates and of the temperature profiles in glass meldng furnaces the dissolving potential in furnaces could be calculated. Three possible routes of silicon stones through special types of furnaces show the respective dissolving potential for silicon. The potential for dissolution of elementary Silicon for the calculated types of Container glass furnaces is nearly the same. The dissolution rates could be improved by raising the temperature of the glass bath in the furnace and by raising the dwell time of the silicon stones in the furnace.
- ItemInfluence of glass/mould interfaces on sticking(Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 2005) Pech, Jérôme; Berthomé, Gregory; Jeymond, Michel; Eustathopoulos, NicolasThe sticking of glass on mould materials is a critical problem since it can lead to the Interruption of glass Container production. This study is a contribution to understanding the phenomena at the origin of sticking. The experiments involve loading and spreading glass gobs on flat metallic Substrates. They are performed directly on a glassmaking machine, thus the thermal conditions of the processes are simulated as closely as possible. Special attention is paid to characterizing the metal and glass surfaces before and after contact using a surface profilometer, AFM, and SEM with an EDX spectrometer. The influence on sticking of mould temperature, surface roughness and surface chemistry (nonoxidized, pre-oxidized and lubricated) is investigated.
- ItemEvolution of the compositions of commercial glasses 1830 to 1990. Part II. Container glass(Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 2005) Smrček, AntonínThis paper treats container glasses in the same way as an earlier paper reviewed flat glass compositions. Data for more than 970 analyses of container glasses manufactured during 150 years in 37 countries have been collected and analysed. The data obviously include containers made by hand as well as by machine from green, white and amber glasses. Compositions developed along two lines, one being green and brown glasses coloured by manganese; such glasses were characterized by low alkali content compensated by increased RO and higher AI2O3 contents. The other, younger, line includes white glasses historically descended from old "forest glasses" and closely related amber glasses. The compositions of both lines converged gradually, so that from about 1970 all container glasses have fallen within a narrow range of compositions, differing in little but their colouring oxides. Differences between particular producers and countries have decreased a great deal.
- ItemEffect of some nucleating agents on thermal expansion behaviour of Li2O-BaO-Al2O3-SiO2 glasses and glass-ceramics(Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 2005) Khater, Gamal A.; Idris, Maher H.The thermal expansion behaviour of some glasses and glass-ceramics within the system spodumence (LiAlSi2O6)-celsian (BaAl2Si2O8) containing LiF, TiO2 and Cr2O3 as nucleation catalysts was described. LiF and TiO2 were found to increase the thermal expansion of the glasses investigated, whereas Cr2O3 slightly lowered the expansion coefficient. The dilatometric transition and softening points of the glasses showed the reverse behaviour. The thermal expansion of the glass-ceramics was a function of type and amount of nucleating agent and heat treatment which greatly affected the mineralogical constitution of the materials.