ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
Your search history is empty.
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Inorganic Chemistry  (6,777)
  • Industrial Chemistry  (1,476)
  • Wiley-Blackwell  (8,253)
  • 1985-1989  (3,587)
  • 1950-1954  (2,931)
  • 1915-1919  (1,735)
Collection
Keywords
Publisher
  • Wiley-Blackwell  (8,253)
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Performance of an RTL contactor for gas-liquid systems: Effective interfacial area and volumetric mass transfer coefficient by oxidation of sodium sulphite solution (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 15-19 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Effective interfacial area a and volumetric liquid-side mass transfer coefficient kLa of an RTL contactor were obtained at different stirring speeds by absorption of oxygen from air into 0.8 kmol/m3 sodium sulphite solution, in the presence of Co++ ions. The values of a and kLa ranged from 80 to 150 m2/m3 and 0.0003 to 0.00053 s-1, respectively, when stirrer speed was increased from 8 to 40 rpm. When kL alone was evaluated, it was found to be practically constant, irrespective of stirring speed.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120104
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Selective hydrogenation: Kinetic investigation of 1, 3-cyclo-octadiene and cyclo-octene hydrogenationDedicated to Prof. Dr.-Ing. Hanns Hofmann on the occasion of his 65th birthday (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 45-53 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The vapour phase hydrogenation of 1,3-cyclo-octadiene (COD) over Pd on alumina has been studied in the gas phase, using a recycle reactor. The dependences of COD hydrogenation rates and those of the consecutive cyclo-octene (COE) hydrogenation on the reaction conditions are well described by a model which takes into account mass transfer in the porous layer of palladium. The kinetics of the COE hydrogenation is of a Langmuir-Hinshelwood type. The hydrogenation of COD is of first order with respect to hydrogen. The reaction order with respect to COD is -0.15. If the catalyst surface is completely covered by COD, the hydrogenation of COE is totally suppressed. This indicates a much stronger adsorption of COD than of COE. Hydrogenation of COE can only occur in the innermost part of the pores when the transport of COD by diffusion is insufficient to supply the entire active surface of the catalyst. This happens if the ratio PH2/PCOD exceeds 2/ϕ2 with ϕ being the Thiele's modulus. This relationship permits a simple evaluation of the effective diffusion coefficient in the porous Pd-layer.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120109
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Increase in viscosity and its influence on polymerization processesDedicated to Prof. Dr. Heinz Gerrens on the occasion of his 65th birthday (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 71-87 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In the course of polymerization in homogeneous systems, the viscosity of the reaction mass increases by several orders of magnitude. The viscosity increase is affected by reaction conditions, concentration and properties of the formed polymer. Empirical correlations for homogeneous and heterogeneous polymerizations are given. Viscosity significantly affects the polymerization kinetics as well as heat, mass and momentum balances of the polymerization reactor. The influence of viscosity and its increase on conductive heat transfer, stirrer power input and cooling capacity, molecular diffusion and mass transfer coefficients, mixing time and residence time distribution in homogeneous and heterogeneous polymerizations in stirred tank and tubular reactors is reviewed.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120112
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    The pressure ratio of critical two-phase flowsDedicated to Professor Dr. h.c. Dr.-Ing. Heinz Brauer on the occasion of his 65th birthday (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 89-96 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Depressurization of a pressure vessel, containing a liquid or a gas is limited by the maximum possible mass flux. This flux occurs at a certain drop in pressure. The ratio of ambient pressure to that inside the vessel must be less than a certain critical value. The critical pressure ratio depends on the thermodynamic state of the fluid inside the vessel and on the geometry of the outlet cross-section. The outlet can be a pipeline, a safety valve or a rupture disk. The results of known theoretical and experimental work are presented. In previous experiments, saturated liquids, two-phase flows or pure vapours were examined. In order to predict the critical pressure ratio, certain assumptions are necessary. These are derived for three well-defined cross-sections of the vessel outlet.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120113
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Heat and mass transfer during condensation of steam in the presence of air at pressures of up to 21 bar (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 235-244 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Film theory under consideration of one-sided diffusion is a satisfactory basis for the calculation of vapour condensation from a flowing turbulent mixture with non-condensable gases. At atmospheric pressure and low condensate flow rates, coefficient equations for smooth tubes are used as a rule. At higher pressures and thus, at higher temperatures and gas densities, there are additional parameters. For instance, non-ideal behaviour of the gas phase or the surface roughness affects the condensation process. These parameters were examined in a test plant under variation of pressure, steam concentration and temperature in a vapour/air mixture. At pressures of up to 21 bar, the Reynolds number of the gaseous phase reaches a maximum value of 128 000 and of 720 for the condensed phase. After description of the test facility, the experimental results are explained and discussed. It is shown that the experimental results are not in a good agreement with the common calculating methods. Taking into account the non-ideal behaviour of the steam/air mixture and the roughness of condensate surface by using a friction factor ξr, all the results could be calculated with an accuracy of ± 20%. This was achived with a modification of the coefficient equation of Gnielinski [1] and by using the equation of Andreussi [2] for the friction factor of a cocurrent annular flow. With respect to one-sided diffusion, the film theory is still applicable. The described method for the determination of local transfer coefficients includes the common calculating method. It represents an extension of the general validity of the film theory.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120132
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Influence of turbulence on transient premixed flame propagation inside closed vessels (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 226-233 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The explosion behaviour of CH4/air mixtures inside a closed 0.065 m3 spherical and a 1 m3 cylindrical vessel was investigated to determine the effect of turbulence on the structure and propagation rate of transient turbulent flames for different initial turbulence levels generated by 4 ventilators installed inside the equipment. Laser-Doppler and hot wire anemometry were used to measure the turbulent motion. It was found that fairly uniform turbulence could be achieved in the central zones of the vessels and that the RMS-values of flow velocity were proportional to the ventilator speed. The evaluation of burning velocity from the pressure/time records showed that, starting from an initial burning velocity which depends on the initial turbulence level, the flame accelerates as a result of pressure, temperature and turbulence effects. Maximum burning velocity coincides with the inflexion point of the pressure/time curve, and is followed by a rapid deceleration of the flame front. A linear relationship between burning velocity and measured RMS-velocity is recognized in the observed range of RMS-values.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120131
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Study of mass transfer in a centrifugal film apparatus (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 245-248 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Mass transfer data are presented for absorption of oxygen in a centrifugal film apparatus. The apparatus was designed to exclude the formation of foam by gas dispersion in liquid. Cells and micro-organisms are not subjected to high shear stress. Therefore, this equipment can be applied in fermentation processes. In the present work, experimental data and correlations were obtained on splitting of the liquid film and oxygen absorption into the film through a spiral ridge formed on the conical surface. The performance of the apparatus is found to be equivalent to those of other types of absorbers.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120133
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Porosity and permeametry at sub-atmospheric pressures (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 255-261 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The Carman-Kozeny equation is applicable in the viscous flow regime but, as the powder becomes finer, this equation fails. The controlling factor is the ratio of the hydraulic diameter to the mean free path of gas molecules (rH/λ) and, as this approaches unity, “slip flow” occurs. This effect increases with (a) increasing fineness, i.e. rH reduced, (b) decreasing porosity, i.e. rH reduced, and (c) decreasing pressure, i.e. λ increased. In order to account for the enhanced flow arising as a result of this failure, a second term is introduced into the equation and this includes an unknown “constant” (δK0/K), the coefficient of slip. It was considered probable that this so-called constant was a function of (rH/λ), and an attempt was made to investigate this relationship.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120135
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Characterization of mixing and residence time distributions in nozzle-type reactors (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 262-269 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Studies of flow characteristics and residence time distribution, (RTD), have been undertaken in a range of geometrically similar, laboratory nozzle-type reactors. High-speed cine-photography was employed to record the complex phenomena of liquid mixing in the reactor and also to record on film the colour of an injected tracer solution leaving in the effluent. A novel atomic absorption spectrophotometric (AAS) technique was applied to transform the results of the latter film into response curves. This technique provide detailed quantitative data on the residence time distributions (RTD) for different feed rates. A multiparameter model, comprising a network of CSTR's and plug flows, was developed to simulate the experimental response data. Good agreement was obtained between model predictions and experimental results. The experimental technique and theoretical approach are recommended for analyzing the flow patterns and mixing mechanisms in such reactors.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120136
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Streamline-upwind/Petrov-galerkin finite element methods in polymer processing (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 269-273 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120137
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Vapour-liquid equilibria of hydrogen/coal liquid and methane/coal liquid systems at elevated temperatures and pressures (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 280-288 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A cubic equation of state is modified in such a way that prediction of PVT data from 40 model compounds, typical of coal oil, becomes possible with an absolute mean deviation of less than 2% for saturated liquid volumes and vapour pressures 〉 1 bar. Additional correlations for binary interaction parameters are obtained by an optimization procedure using vapour-liquid euilibrium (VLE) data from known heavy hydrocarbon liquid/light gas systems. When the modified equation is applied to coal-derived liquids, only specific gravity and boiling analysis data of the coal liquids are required, primarily in order to determine the equation-of-state parameters. The proposed equation is shown to allow a good prediction of VLE data for systems consisting of wide-boiling-range coal oils and light gases. Experimental values were obtained at elevated temperatures and pressures with a circulation flow apparatus.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120139
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Heat transfer enhancement in fin-plate heat exchangers by wing type vortex generatorsDedicated to Professor Dr. Klaus Gersten on the occasion of his birthday. (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 288-294 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Heat transfer and fluid mechanical data were computed for laminar channel flows containing strong longitudinal vortex pairs. The strong vortices are generated by thin delta wings and delta winglet pairs of low aspect ratios and large angles of attack. These wings are attached to the channel walls. The data show that longitudinal vortices cause high local peaks in heat transfer and marked increases in the overall channel heat transfer. These increases occur over a wide region of channel wall, compared to the vortex generating wing area. The results are of special interest for compact heat exchangers. The heat transfer enhancement allows a considerable reduction in the heat transfer area which, in turn, reduces the manufacturing and operating costs.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120140
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Fluid dynamic description of jet-loop reactors in multiphase operationModified version of a paper presented by K.H. Tebel at the “Jahrestreffen der Verfahrens-Ingenieure”, Strasbourg, September 17 to 19, 1986. (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 274-280 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A superposition of simple physical equations allows a satisfactory, comprehensive fluid dynamic description of jet-loop reactors in multiphase operation up to a dispersed phase hold-up of 15%. In the case of higher concentrations, there are further interactions which are not yet included in the model description. Apart from the drag coefficient of the single-phase jet loop, information on the particle swarm behaviour, i.e. on the slip velocity of the dispersed phase is required. Explicit formulation of the influence of the relevant geometrical parameters permits a reliable scale-up without additional adaptation parameters.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120138
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Incorporation of gradient into random search optimizationPresented at the Second Canadian-German Workshop on Chemical Engineering Mathematics, Bad Honnef, Fr Germany, May 30-June 2, 1988. (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 309-318 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: To improve the rate of convergence of random search optimization procedures, the incorporation of a gradient-oriented one-dimensional search is investigated. With this modification to the random search procedure based on uniform sampling and region contraction [1], convergence to within 0.01% of the global optimum was obtained substantially faster for typical chemical engineering problems. It was also found that the reliability of obtaining the global optimum was improved.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120143
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Particle collection in small laboratory cyclones as a basis for the design of large-scale cyclonesPaper presented by H. Büttner at the “Jahrestreffen der Verfahrens-Ingenieure”, Freiburg September 30 to October 2, 1987. (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 295-301 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Grade efficiencies must be measured in order to characterize particle collection in cyclones. For real, irregularly shaped partcles, the grade efficiencies depend on the shape and orientation of the particles and the flow around them. Therefore, the collection characteristics of cyclones should be defined in relation to spherical particles. Deviations occurring on the use of real, irregularly shaped dusts can then be attributed to a material influence. A fast and accurate measuring technique to determine the collection characteristic for spherical particles is described, followed by the presentation of results of extensive investigations on small model cyclones. A similarity relationship is presented. The validity of this relationship was confirmed by investigations with similar, larger cyclones.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120141
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Leakage rates of refrigerants through cracksPaper presented by F. Westphal at the European Two-Phase Flow Group Meeting, Université Catholique de Louvain, Brussels, May 30 to June 1, 1988. (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 301-308 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An independent preliminary mechanistic prediction method for leakage rates through small slit-shaped through-wall cracks, based on coupled pressure drop and (critical) mass flux calculation is presented. The predictions are verified against initially subcooled liquid refrigerants and water data collected during experiments in real and model cracks in a wide range of parameters. The achieved accuracy of prediction is already comparable to that of the experimental results. Further model modifications are put forward.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120142
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Heat transfer to liquids and suspensions in agitated narrow vesselsPaper presented by D.-H. Frobese at the “Jahrestreffen der Verfahrensingenieure”, Hannover, September 21 to 23, 1988. (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 324-332 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The knowledge of the heat transfer coefficient on the inner side of a heated vessel wall is of the utmost importance for the design of agitated vessels. In the case of large Reynolds numbers, the heat transfer is mainly determined by these numbers whereas, with small Reynolds numbers, the heat transfer is better described by considering the Grashof number. Investigations of heat transfer in agitated narrow vessels have shown that the height/diameter ratio exerts virtually no influence on the heat transfer when multi-impeller stirrers are used. The heat transfer to stirred suspensions can be described by relationships valid for liquids if the characteristic data of the liquid are replaced by those of the suspension and when the solids volume concentration is also taken into account. This relationship allows the heat transfer coefficient to be calculated for given solids volume concentrations of up to 60%.
    Additional Material: 22 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120145
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Design and analysis of a state observer for the temperature front of a retification columnExtended version of a paper presented by G. Feig at the “Jahrestreffen der Verfahrens-Ingenieure”, Hannover, September 21 to 23, 1988. (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 339-344 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In order to achieve optimal energy-saving, load-dependent operation of rectification columns, development and implementation of model-based control concepts are necessary. This paper reports on the design and step-by-step testing of a state observer for the estimation of two state variables which cannot be measured directly, namely the vapour rate and the location of mass transfer zone (temperature front) in the stripping section of a production column. The procedure is described, and the relevant simulation and operation results are presented and discussed. Initial experience, gained when the concept was put into practical operation, is reported.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120147
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Generalization of AIChE and colburn models for tray efficiency (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 333-339 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The most important investigations on liquid weeping and entrainment in plate columns with downcomers are reveiwed. The formulae for calculating column plate efficiency under conditions of liquid weeping and entrainment have been derived on the basis of mass balance equations. The presented model is a generalization of the models of AIChE and Colburn. Sample results are shown graphically. The effect of liquid entrainment on tray efficiency predicted by the model is in agreement with experimental data of FRI.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120146
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Selective absorption of ethylene by methanol solutions of Copper(I) chloride-ethylenediamine complex (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 356-357 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120150
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    Continuous crystallization of potassium carbonate (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 345-350 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Continuous crystallization of potassium carbonate was investigated in a mixed suspension mixed product removal (MSMPR) crystallizer with 7.0 1 working volume. Highly polydispersed product was obtained, with x50 varying between 320 and 670 μm. Crystal growth rates can be described by the model of Abegg, Stevens and Larson (ASL) (size dependent crystal growth rate). Values of G0 = 8.6 × 10-9 to 3.6 × 10-8 m/s and B0/ϕ = 2.7 × 108 to 4.2 × 109 1/m3s were obtained for mT = 45 to 92 kg/m3 and ε = 0.45 ± 0.05 W/kg. Nucleation kinetics at 27 °C can be described by the equation: B0/ϕ = kBϕsε0.73G02.5. Since G0 ∝ σ, convection and/or diffusion rather than surface integration are the crystal growth controlling mechanisms.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120148
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Experienmental and theoretical combustion rates of graphite plates in hot parallel flows of air and O2/N2 mixturesPaper presented by H. Wilhelmi at the “Jahrestreffen der Verfahrens-Ingenieure”, Hannover, September 21 to 23, 1988. (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 351-356 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Combustion rate of flat graphite plates in oxidizing flows with velocities of up to 80 m/s and stagnation temperatures between 1600 and 2500 K were investigated. The flow field and its local properties were recorded in addition to surface temperature of the solid sample and change in surface structure. The experiments, in which the surface temperature of graphite was adjusted and carefully controlled by radiation shields, indicated that, under these experimental conditions, between 15 and 20 wt-% of carbon was lost as particles of up to 100 μm which burnt rapidly in the boundary layer region. Subtraction of erosion rates from the recorded global combustion rates yield the heterogeneous chemical reaction rates, which are approximated by an Arrhenius type function for the mathematical modelling. Since steep temperature and concentration gradients occur in the boundary layer, the local values of the multicomponent transport coefficients were evaluated in order to design a more realistic computational procedure which, in addition, also includes radiative heat transfer. Computational checks revealed that, in the past, the assumption of mean constant values for the transport coefficients has led to errors of up to 100% in the evaluation of the chemical reaction and global combustion rates.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120149
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    A study of gas and liquid distributions in structured packingsPaper presented by R. Stikkelman at the “Jahrestreffen der Verfahrens-Ingenieure”, Hannover, September 21 to 23, 1988. (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 445-449 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This study describes the gas and liquid distributions in a column with structured packings. The column is 0.5 m in diameter. It is equipped with a total of 1289 detectors in the top and bottom cross-sections. These detectors provide a detailed picture of the gas and liquid flows through elements of only 25 × 25 mm2. The maldistribution in the gas bulk flow is negligible. Only the observed wall can contribute to malperformance. The gas flows in parallel to sheet orientation, thus introducing a radial transport. Together with the change in the orientation of subsequent packing elements, this results in good gas mixing. It was observed that the liquid wall flow rate decreases when the gas velocity exceeds 1.7 m/s. Up to the loading point, the maldistribution of the liquid is constant. Above this point, the equality of the distribution deteriorates rapidly, due to the occurrence of large-scale liquid segregation.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120164
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Investigation of a wet dust scrubber with a pneumatic nozzle: Dust collection based on turbulent diffusionPaper presented by P. Centner at the “Jahrestreffen der Verfahrens-Ingenieure”, Hannover, September 21 to 23, 1988. (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 439-444 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The “nozzle scrubber” is a wet scrubber in which the scrubbing water is dispersed in dust laden gas stream by means of one or more pneumatic nozzle. This scrubber is distinguished by an excellent collection efficiency for submicron dust at an unusually low energy and water consumption. So far, the physical effects affecting the separation cannot be explained by a well-defined theory. Therefore, it is sensible to investigate the collection efficiency with regard to the mechanisms of inertial impaction, turbulent diffusion and coalescence induced by turbulence. The experimental equipment is of a very simple design. A light scattering device was used to measure the particle distributions. In addition, electron micrographs were analyzed to obtain information about the submicron particles. The influence of operating parameters on grade efficiency has been demonstrated by their systematic variation. The contribution of turbulent diffusion to the collection efficiency has been confirmed; nevertheless, grade efficiencies were also measured when inertial impaction prevailed.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120163
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    Masthead (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989) 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120101
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    IR study of chlorination of alumina employing mixtures of gaseous chlorine and carbon monoxideDedicated to Professor Dr.-Ing. Hanns Hofmann on the occasion of his 65th birthday (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 27-32 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The chlorination of an alumina with BET surface area of 100 m2/g has been studied in situ by transmission IR measurements at about 670 K. The chlorinating gases consisting of Cl2 and CO were employed individually and in equimolar proportion. The IR results do not reveal the presence of a phosgene surface species which could support the only mechanism proposed so far to explain the chlorination. A detailed alternative reaction mechanism is suggested for the high temperature chlorination reaction, taking into account the IR results, together with the known electron donor-acceptor properties of the activated alumina and the reaction gases: Cl2 molecules accept electrons from oxide ions with a lower coordination number on the alumina surface, leading to the formation of Cl-and Oad. While Cl- yields AlCl3, Oad reacts further with CO producing CO2.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120106
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    Heat transfer to submerged surfaces in coarse-grained pressurized fluidized beds and fixed bedsPaper presented by J. Schweinzer at the “Jahrestreffen der Verfahrens-Ingenieure”, Freiburg, September 30 to October 2, 1987. (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 38-44 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This contribution reports on the theory underlying a uniform representation of heat transfer to submerged surfaces in fixed bed reactors and of gas convective part of heat transfer in fluidized beds with coarse-grained bulk solids and/or at elevated pressure. Based on an analysis of the pressure drop behaviour of fixed bed percolation at different gas pressures and with different bulk solids, a new dimensionless pressure drop parameter was developed. Fixed bed heat transfer data are very well correlated by this new dimensionless number. As soon as fluid throughput is in excess of minimum fluidization velocity, the pressure drop parameter transforms into the well-known Archimedes number. These two dimensionless numbers are connected by the condition of equilibrium for pressure drop and mass of practices in a fluidized bed. This equilibrium is fulfilled as soon as fluidization commences. Up to now, the Archimedes number has been generally accepted as the significant parameter, determining the gas convective part of heat transfer in fluidized beds; however, without any physical interpretation of this parameter. Introduction of the pressure drop number, which is consistent with the Archimedes number, reduces the heat transfer behaviour to pressure drop characteristics. The usefulness of this concept is proven by the comparison of experimental results and prediction.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120108
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    Reversible absorption of nitric oxide in low volatile organic liquids containing cupric halides (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 33-37 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The absorption of nitric oxide (NO) in phosphoric acid esters and polyethylene glycol ethers which contain cupric halides has been investigated. Due to high solubility of cupric halides and high equilibrium constants of formed nitrosyl complexes, the effective solubility of nitric oxide can be enhanced to about 100-fold its solubility in the salt-free organic liquid which itself amounts to only about 5-fold the NO-solubility in water. Calculations taking into account flue gas conditions indicate that the required gas-liquid ratio in industrial absorption processes will lie in the normal range of flue gas scrubbing processes, namely in the region of 400:1 to 1000:1 in volume. Thus, such a reversible absorption process could a viable alternative to SCR-processes in flue gas denitrification.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120107
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    Separation of liquid from vapour upon pressure relief (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 54-63 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: When a chemical reactor is depressurized or pressure in a vessel, filled with saturated liquid, has to be decreased, generally both vapour and liquid flow out through the relief valve. Since chemical reactors are usually operated with toxic and explosive fluids, the discharged liquid which vaporizes on the ground around the vessel may reach dangerous concentrations, causing explosions or accidents with the poisonous gas. During a research project, some fundamentals were developed for the design of separation systems which separate liquid from vapour and store it in a receiver. The requirement for a separation efficiency of a least 80% is related to the condition that the separated liquid should flow back into the reactor still during the pressure relief phase. For safety reasons, both separation and re-storage are to be carried out without the supply of external energy. Theoretical and experimental investigations of pressure distribution within the piping to the relief valve and in an integrated separator show that re-storage of the separated liquid in the vessel can be achieved under certain flow conditions. Therefore, the separator must be integrated in the pipe at a certain height above the vessel, so that the hydrostatic pressure of the separated liquid, corresponding to the difference in height, is sufficient to lead it back through another pipe against the internal pressure of the vessel. First, several separators were tested with air-water mixtures. A swirl separator and a reversing separator have been developed to such an extent that they appear suitable for the set task. Experimental results with air-water mixtures and refrigerant R12 upon pressure relief show separation efficiencies of between 90 and 100% at low pressure drops within the whole operating range. As an alternative to separation outside the vessel, a rotary separator was also developed which is fixed to the outlet opening in the vessel. A centrifugal field is produced by the separator rotor and the heavier liquid is largely separated from the vapour so that only drops in the range 〈 100 μm flow together with the vapour towards the central standpipe. The outflowing vapour leaves the separator via 4 tangentially arranged nozzles, under critical conditions. The vapour flow momentum drives the separator rotor. The arrangement was developed and tested during various series of experiments, under conditions or pressure relief with refrigerant R12. So far, separation efficiencies between 60 and 95% have been achieved at stirring speeds of up to 2500 min-1.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120110
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    Absorption process for the removal of organic solvents from exhaust air (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 63-70 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: It is shown in this report that, under certain conditions, cleaning of exhaust air by absorption presents an interesting alternative to the existing methods. In particular, this process can be used with advantage for small quantities of exhaust air, high and strongly fluctuating solvent concentrations and solvent mixtures such as those occurring in batch operation. A washing agent was employed which had not been previously used for this purpose. Its properties, which were investigated in the laboratory, were confirmed during a 15-months' trial period in a semi-industrial plant. The process and plant were optimized for practical use. Through its option of solvent recovery from exhaust air, this physical absorption process contributes to environmental control.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120111
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    Determination of size and stress intensity factors for leaks in nozzle attachmentsPaper presented by G. Wiedemann at the “Jahrestreffen der Verfahrens-Ingenieure”, Freiburg, September 30 to October 2, 1987. (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 131-137 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The prediction of leak areas in pressure vessels is an important objective in the safety analysis of chemical plants. Using suitable design rules, a leak-before-break behaviour can be achieved. This contribution outlines a procedure for the leak-before-break design of nozzle attachments and the determination of the size of the corresponding opening area. In addition, K1-factors and leak areas for a number of nozzle geometries have been calculated and plotted.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120118
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    Simulation of primary and secondary reformers for improved energy performance of an ammonia plant (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 358-364 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The energy consumption of ammonia plants based on steam reforming of naphtha or natural gas can be reduced by shifting the reforming load from the primary to the secondary reformer. It is shown that lowering of the primary reformer operating temperature 20 °C results in 2% increase of unconverted methane content in the outlet stream. The increased methane content can be processed in the secondary reformer if the process air inlet temperature is increased to 400 °C. The lower operating temperature reduces the energy consumption of the primary reformer by about 6% (and the overall consumption by about 2%) and also prolongs the service life of reformer tubes.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120151
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    Overproduction of lipase with staphylococcus carnosus (pLipPS1) under modified gravity in a centrifugal field bioreactorReport from SFB 145 “Biological, chemical and technical fundamentals of bioconversion” (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 364-373 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Fermentation under modified gravity could be of interest in application to (a) increasing productivity of growth and growth linked production with microorganisms at high cell densities and (b) increasing the productivity of highly viscous pseudoplastic polysaccharide fermentation. In both cases, higher oxygen transfer rates in centrifugal fields result in higher productivities since these fermentations are usually oxygen limited. A further aspect of fermentation under increased gravity is the reduction of foam since foam coalescence time decreases with acceleration number. On the other hand, under microgravity, shear reduction would allow growth and production even for very shear sensitive organisms. In order to carry out fermentations under modified gravity, a special type of fermenter-the centrifugal field bioreactor CFBR-has been developed at the Institute of Chemical Engineering (Head: Prof. Mersmann) of the Technical University of Munich. For the first time, exoprotein biosynthesis of lipase with S. carnosus has been carried out under sterile and controlled conditions in this novel bioreactor, in presence of increased mass forces.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120152
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    Measurement of heat transfer coefficients in tubes by temperature oscillation analysisPaper presented at the “Jahrestreffen der Verfahrens-Ingenieure”, Hannover, September 21 to 23, 1988. (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 379-387 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An experimental technique and evaluation method is described for the determination of local heat transfer coefficients in tubes or other ducts. By means of a rotary mixing valve, cold and warm fluid flows are mixed in order to generate an arbitrarily shaped but periodically oscillating inlet temperature profile at the test tube. The propagation of the fundamental harmonic oscillation from the fluid to the outer surface of the tube wall is calculated analytically. Comparison of fluid and wall oscillations yields the heat transfer coefficient to be measured. The inaccurate measurement of fluid bulk temperature in the centre of the cross-section is compensated by an additional correction. Experiments were carried out with turbulent water flow through a copper tube. Measured heat transfer coefficients were compared to values calculated using Hausen's equation and good agreement was obtained.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120154
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    Directional specific shear-rate measurements in gas-liquid two-phase flow (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 374-378 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Wall shear rate vectors in a bubble column and an airlift-loop reactor were measured using the limiting-current electrodiffusion technique. In connection with a new circular three-segment probe, the magnitudes and directions of shear rates were determined. The results for the bubble column are in good agreement with hot film-anemometry measurements in the same column. Moreover, the spiral flow structure, postulated in the shear-zone model of Franz, has been confirmed. In addition, the measuring technique was used to determine the flow structure in an airlift-loop reactor employed for the cultivation of animal cells. The region above the gas distributor of this fermenter has been identified as critical for mechanical damage to the cells.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120153
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    Effect of transfer on droplet size in liquid-liquid dispersions (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 395-399 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Mean droplet diameter of the dispersed phase in pulsed plate extraction columns was measured for binary and ternary systems. A change in the droplet size in the presence of solute, dependent on such factors as the direction of mass transfer, droplet size in the binary system, radio of diffusion coefficients, viscosity of the continuous phase, interfacial tension and driving force for extraction was observed. Two new empirical correlations of mean droplet sizes in mass transfer conditions are proposed. These correlations have been successfully applied to other extraction columns.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120156
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    Flow phenomena and local heat and mass transfer in corrugated passagesPaper presented by G. Gaiser at the “Jahrestreffen der Verfahrens-Ingenieure”, Hannover, September 21 to 23, 1988. (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 400-405 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Flow phenomena, local heat and mass transfer and pressure drop of corrugated passages in process equipment are examined. Based on a method for measuring local heat and mass transfer, developed in previous investigations, a procedure has been formulated for the determination of local heat and mass transfer in corrugated passages. Using the analogy between heat and mass transfer, this technique allows the determination of heat transfer distributions in any structures with high local resolution. The corresponding pressure drop is presented together with the local and integral heat and mass transfer of different structures. It is shown that differences in heat and mass transfer as well as in pressure drop are due to different flow phenomena which also characterize mixing behaviour.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120157
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Evaporation rate and separation factor of molecular distillation in a falling film apparatus (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 406-413 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: During molecular distillation in a falling film apparatus, temperature and concentration of the more volatile components undergo a marked decrease in axial and radial directions, due to the distillation in vacuo. The gradients produce changes in the rate of surface evaporation and separation efficiency along the flow path. A theoretical study of this problem is presented for binary mixtures. The respective differential equations for heat and mass transfer in the liquid film are solved numerically. As the results demonstrate, the aspect ratio of an apparatus should be large when a high separation is required and small when a high distillation rate is more important.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120158
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    The importance of dynamic performance and testing of industrial thermometers in process control (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 419-426 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This paper considers the dynamic performance of instruments in control systems. Errors connected with transient measurements are discussed. It is shown that it is not always proper to assign common statistical properties to these dynamic errors. Emphasis is placed on temperature sensors. Common industrial thermometers are described and factors affecting their response discussed. An a-priori dynamic performance prediction procedure is presented. This permits preinstallation estimation of response characteristics of sensors used in industrial processes. Sensors in service also require performance assessment since they can deteriorate with use. In-situ testing is useful for this purpose and a recently develolped procedure is described.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120160
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    Parameters influencing the mean particle size of a crystalline productPaper presented by A.B. Mersmann at the “Jahrestreffen der Verfahrens-Ingenieure”, Hannover, September 21 to 23, 1988.Dedicated to Professor Dr.-Ing. Dr. h.c. Ernst-Ulrich Schlünder on the occasion of his 60th birthday (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 414-419 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Crystallizer design has to take into account the physical and chemical properties of the solution and solids as well as the geometry, type and operating conditions of the crystallizer. The most important property of a crystallizing system is its solubility. High solubility leads to low relative supersaturation and large mean crystal size, and vice versa. High solubility systems can be sensitive to abrasion and attrition. For low solubility systems, mixing is crucial.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120159
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    On-line measurement of partical size distribution and partical concentration in suspensions by ultrasonic spectrometryPaper presented by U. Riebel at the “Jahrestreffen der Verfahrens-Ingenieure”, Hannover, September 21 to 23, 1988. (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 433-438 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The principle of ultrasonic spectrometry is based on the measurement of the ultrasonic extinction caused by the presence of particles. From measurements at different frequencies and with the knowledge of the ultrasonic extinction cross section of the particles, a system of linear equations can be established and solved to obtain the particle size distribution and particle concentration. With an experimental apparatus covering the frequency range from 1.7 MHz to 81 MHz, particles ranging from 20 to 1000 μm in diameter may be analyzed. The measurements can be carried out with particle concentrations as high as 10% by volume.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120162
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    Parameter estimation from integral Mars-van Krevelen type of kinetic data of a reaction networkDedicated to Professor Dr. Horst Langemann on the occasion of his 60th birthday (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 11-14 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120103
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    Micromixing limits in an MSMPR crystallizer (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 1-11 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The effect of micromixing limits on a process of crystallization in an MSMPR crystallizer is studied with respect to power law growth and nucleation kinetics. Three limiting cases corresponding to maximum mixedness and complete segregation in an MSMPR crystallizer and plug flow configuration were analyzed for processes in which supersaturation is generated by conventional techniques. The sensitivity of these three limiting cases to the supersaturation generation term in each mode of operation was investigated using several numerical examples. The study demonstrates the effects of mixing on the overall crystallizer performance and, in particular, the enormous micromixing influence at high supersaturation generation rates. The difference in the product CSD arise from the variations of supersaturation profiles experienced by the elementary volumes throughout their sojourn. Characterization of mixing in a real crystallizer at some intermediate levels is emphasized with the aid of relevant industrial examples.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120102
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    Coupled simulation of heat transfer and reaction in a steam reforming furnaceDedicated to Professor Dr. Hanns Hofmann on the occasion of his 65th birthday (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 20-26 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: For design and simulation of chemical process furnaces in accordance with present-day standards, the temperature distributions in the firebox and in the reactors must be generated simultaneously. This calls for coupling of the simulations of the firebox and of the reactor. For the calculation of heat transfer in the firebox, a generalized furnace simulations program, based on the zone method, is applied. Monte Carlo simulation techniques are used to determine the view factors. The location of the burners is explicitly accounted for. Absorption and emission of radiation by the flue gas are calculated by considering band contributions for carbon dioxide and water. For the simulation of the steam reforming reactors, a one-dimensional heterogeneous model, which accounts for the presence of intraparticle partial pressure gradients, is used. The simulated temperature distribution in the furnace is in excellent agreement with industrial results, as is the simulated product distribution.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120105
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    Effects of pretreatments on semi-continuous anaerobic digestion of wheat straw (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 96-102 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The effects of alkali treatment, nitrogen supplement and hydraulic retention time on methane production rate from semi-continuous anaerobic digestion of 5% wheat straw-water mixtures were investigated. The experiments were carried out in laboratory scale fermenters, fed with 1 1 of basic, alkali treated and nitrogen supplemented 5% wheat straw-water mixtures, respectively, and maintained at 55 °C. Digestion experiments were performed for hydraulic retention times of 8, 10 and 15 days. The amount and composition of produced gas were measured until steady state was attained in each run. The steady-state methane production rates were found to increase with hydraulic retention time and with the type of slurry in the following order; basic, nitrogen supplemented and alkali treated slurry. Data obtained from the experiments were employed to determine the kinetics of methane production from anaerobic digestion of wheat straw, for the assessment of pretreatment effects on process kinetics. The predicted methane production rates were found to be in a reasonably good agreement with the measurements.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120114
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    Simulation of sintering of model supported metal catalysts (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 103-109 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: During the past decade, the sintering of model supported metal catalysts, i.e. catalysts consisting of metal deposited on very thin and flat oxide films, has been intensively investigated by transmission electron microscopy. In the current paper, a mathematical model, based on an atomic migration mechanism, for the sintering of these catalysts is presented. The predictions of the model, based on Monte Carlo simulations, are in very good agreement with the experimental observations, i.e. phenomena such as ‘apparent’ particle migration, splitting and neck formation between particles are predicated by the model.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120115
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    Advances in modelling and design of multitubular fixed- bed reactorsI. Description of Interaction Between Reactants and Coolant (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 113-130 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Starting from the review of current industrial designs, the present paper analyzes thermal interaction between reactants and coolant in multitubular fixed-bed reactors. The interaction can be described quantitatively in terms of parameters characterizing transport processes both on the tube side and in the intertubular space. The study provides a detailed discussion of existing methods and correlations used for the evaluation of these parameters. The methods presented here can be considered as a basis for the development of a more comprehensive approach to the modeling and design of multitubular catalytic reactors.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120117
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    Combined process treatment of molasses fermentation waste water for biogas generation (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 109-112 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Anaerobic fermentation of molasses distillery slops to biogas was carried out with the aid of an adapted and selected anaerobic mixed culture. Two different types of fermenters were used, namely an agitated pretreatment fermenter and a column fermenter with glass rings as carriers for micro-organisms. The production of biogas in both fermenters amounted to between 0.6 and 0.8 dm3/g COD. The aerobic pretreatment of distillery slops by T. fermentans, yeast during a 4 to 6 h period allows a high reduction of COD in the subsequent anaerobic phase of the process. After treatment of the distillery slops by T. fermentans, it was possible to convert between 85 and 93% of the organic matter to methane. Conversion was about 93% with loading rate of 25g COD/litre day.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120116
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    A new particle size effect (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 147-154 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The sintering effect of highly dispersed metals is the reason for the following phenomena: thermal deactivation, particle size effect, separable or non-separable kinetics and the isokinetic relationship ( = compensation effect). A comparison of these phenomena reveals a contradiction which can be reconciled by a new particle size effect. This effect is characterized in the following way: The dependence of specific activity on particle size is always connected with a variation of the activation energy, caused by the particle size distribution. Therefore, this effect is referred to as the partical size and distribution effect, P.S.D.E. This new concept describes all the observed phenomena of the conventional partical size effect. Moreover, it is consistent with similar effects such as non-separable kinetics and the isokinetic relationship. In consequence, the method of isothermal measurement of specific activity is inadequate.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120120
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Conversion of methanol to light olefins over zeolite H-T (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 155-161 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The conversion of methanol over zeolite H-T was investigated in a fixed bed reactor. H-T was prepared from Na-T by ion exchange with HCl and NH4Cl solutions. The HCl solution caused appreciable dealumination. High yields of ethene were obtained with NH4Cl exchangeed zeolites Na-T with 45% decationization, high proprne yields with low HCl or NH4Cl Exchanged catalysts. Low methanol partial pressures and short residence times favoured the formation of lower olefins. Lowest coking rates were observed at a reaction temperature of 693 K. The catalytic activity decrased slowly with the number of reaction/regeneration cycles. The distribution of procucts 〉 C2 could be described by the most probable distribution of Schulz and Flory.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120121
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    Advances in modelling and design of multitubular fixed-bed reactorsII. A Mathematical Model of the Cocurrent Multitubular Reactor System (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 170-175 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This paper presents a method mathematical modelling of cocurrent multitubular fixed-bed reactors. The method is adapted to the most widespread type of industrial reactor design, i.e. the system fitted with disk-and-doughnut baffles. The proposed model makes it possible to estimate the influence of non-uniformity of the heat carrier flow on the reactor characteristics, taking into account the coolant streams by-passing via the tube-to-baffle clearances. Based on the model, the effect of the operating parameters as well as of some more important geometrical parameters of the reactor on an exemplary highly exothermic process of partial benzene oxidation to maleic anhydride is discussed.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120123
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    Measurement of aeration capacity of fermenters (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 213-217 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Important aspects of K1a measurement in agitated aerated vessels are briefly characterized from the standpoint of reliability of the measured data. An analysis of the shortcomings of dynamic methods for measuring the K1a is given. A new modification of the dynamic method is proposed, which excludes these inadequacies through a special experimental arrangement. This was verified by comparing the data with those obtained by an independent steady-state method. The new method can serve as a standard of reference, suitable for testing newly developed methods for K1a measurement. The initial response method was tested in this way in non-coalescent liquids, and shown to lead to errors of the order of hundreds of percent. K1a values obtained with the initial response method were found to depend strongly on the probe's location in the vessel.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120129
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    Dispersion behaviour of droplets in circular loop reactors (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 205-212 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A circular loop reactor was built for application to a heterogeneous liquid-liquid reaction. In order to investigate the dispersion behaviour of droplets in the reactor, basic experiments were performed using a number of liquid-liquid dispersions. Droplets discharged form the impeller region were found to grow due to coalescence in the circulation region. Mean droplet diameter decreased exponentially with elapsing time. An expression correlating the steady-state mean droplet diameter with the operating conditions was derived. Moreover, the transition time required for the droplet diameter to reach the equilibrium value was determined and correlated with the operating conditions.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120128
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    The contradiction in the theory of desorption phenomena: A new interpretation of the classical concept for its avoidance (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 218-225 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Most chemical engineers presently accept that the mass transfer rate in desorption from the solid to the gas phase or from the liquid to the gas phase is accelerated with increasing temperature in the liquid or the solid phase, or increasing partial pressure of inert gas in the gas phase, and/or decreasing total system pressure in the gas phase. Nevertheless, many reports about such mass transfer are still based on the former concept, which completely contradicts the actual phenomena mentioned above. Here, we discuss the contradiction and suggest a way of resolving it in terms of diffusion theory.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120130
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    Thermally stabilized combustionPaper presented at the “Jahrestreffen der Verfahrens-Ingenieure”, Hannover, September 21 to 23, 1988. (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 249-254 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Thermally stabilized combustion has a number of unique characteristics which permit the generation of steam or other forms of process energy from the heat of combustion of a gaseous or clean liquid fuel in remarkably compact, integrated apparatus while truly minimizing the concentrations of NOx, CO and unburnt fuel in the effluent. These characteristics, which have been identified by a long-range program of research, are described and the advantages and limitations of this process are discussed.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120134
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    Studies in liquid-liquid direct-contact heat transferPaper presented by E. Marschall at the “Jahrestreffen der Verfahrens-Ingenieure”, Hannover, September 21 to 23, 1988. (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 388-394 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Liquid-liquid direct-contact heat transfer in a spray column was studied numerically for a low hold-up. The solutions of the conservation equations of mass, momentum and energy for both phases agree well with earlier experimental results, if one assumes a rigid liquid-liquid interface. Heat transfer inside is dominated by transient conduction and natural convection. It was found that the Nusselt number for free convection depends essentially only on the Rayleigh number.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120155
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    A new model of the effect of stirring intensity on the rate of secondary nucleationPaper presented at the Anual Meeting of the “GVC-Fachausschuß Kristallisation”, The Hague, March 10 to 12, 1986. (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 137-146 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Secondary nucleation in industrial crystallizers depends on both supersaturation and mechanical stress by stirring. Most models which consider mechanical stress assume that nucleation is proprotional to the energy transferred to the crystals during collisions. This is not based on any physical relationship and, in addition, the models do not satisfactorily reproduce the experimental results. Own model, based on the theory of Hertz/Huber, which accounts for the stress of the crystals caused by impact, gave better results. This well-known and proven theory allows the calculation of the volume abraded during collisions between crystals and stirrer or walls. Introducing a nucleate efficienncy, the effect of mechanical stress on the rate of secondary nucleation, due to stirring intensity and crystallizer size, can be determined.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120119
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    Effects of turbulence on heat and mass transfer in stagnation flowsPaper presented at the “Jahrestreffen der Verfahrens-Ingenieure”, Freiburg, September 30 to October 2, 1987.Dedicated to Professor Dr. Josef Kestin on the occasion of his 75th birthday (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 176-187 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The influence of turbulence on local heat and mass transfer is systematically analyzed. Essential prerequisite is the availability of measurement methods, based on convective mass transfer, which allow the visualization of heat and mass transfer distributions. The results show that, even at low turbulence intensities, the flow and transport phenomena are decisively influenced by the specific design of turbulence grids and the orientation of the grid wires with respect to the stagnation line. Thereby, two different flow mechanisms occur which may interact. The anisotropy of grid turbulence leads to the “wire-gap effect” depending on the actual position of the grid wires in relation to the stagnation line. The other mechanism is based on the wavy wake velocity distribution behind screens and grid which, in conjunction with the centrifugal instability of stagnation flows, may lead to longitudinal vortices. The results indicate why turbulence has not been sufficiently considered in the available (semi-) empirical correlations. Information needed for an accurate prediction of heat and mass transfer in turbulence flows is discussed.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120124
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    Reduction of energy requirements in distillationExtended version of a paper presented at the “Jahrestreffen der Verfahrens-Ingenieure”, Freiburg, September 30 to October 2, 1987. (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 163-169 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Distillation has been, up to now, the standard method for separating fluid mixtures in the process industry and the consensus is that it will remain so for years to come. The only disadvantage of distillation is its high energy requirement. In the following, it will be demonstrated on the example of an ideal ternary mixture, how the energy requirement of distillation process can be reduced. Very effective are some modifications of single columns, optimization of column sequences and direct or indirect column coupling. It will be shown that, just by column coupling, the energy requirement can be reduced to a third.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120122
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    Venturi scrubber calculation and optimization (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 188-195 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Collection efficiency and pressure loss of a venturi scrubber can usually be determined from the calculation models of Barth and Calvert. However, this only leads to reasonable results if the droplets are uniformly distributed throughout each cross-section of the washing zone. In this work, a two-zone models is developed which allows the calculation of the venturi scrubber at operating conditions with a non-uniform droplet distribution. The scrubber geometry is also taken into account. A venturi scrubber was developed on the basis of this new model. Its energy consumption is significantly lower than the well-Known optimum characteristic of Wicke and Holzer. For ideal operating conditions, a new optimum characteristic is given which should be the aim of future optimizations.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120125
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    Model concept of floc disintegration in centrifugal fields (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 200-204 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A model of floc destruction resulting form mass forces in a centrifugal field is postulated and its validity examined. This model is to be regarded as a supplement to the existing shear-loading disagglomeration models. In order to verify this additional floc disintegration mechanism, appropriate investigations were carried out with flocculated suspensions of silica and Hamburg dock sludge. As a result, in addition to floc disintegration by shear forces within a turbulent flow and in the centrifuge inlet, the existence of another mechanism was demonstrated. This consists in the floc destruction in a centrifugal field where particles in excess of a certain size, or specifically heavier components, are preferentially torn out of the floc. This floc disintegration by mass forces can lead to a classification effect in centrifuges which also subject the flocs to instant high centrifugal forces.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120127
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    Mass transfer and chemical reaction in fluid two-phase systemsPresented in part at the 21th meeting of the Dechema-Arbeitsausschuß “Technische Reaktionen” together with the GVC-Fachausschuß “Technische Reaktionsführung” in Aronoldsheim/Taunus, 10-11th February 1982. (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 195-199 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Steady-state concentrations of the transferred reactant in the bulk phase and the non-flowing diffusion boundary layer of an isothermal, isobaric two-phase reactor with an irreversible first-order reaction and constant composition of one phase.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120126
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    A new load cell for measuring normal and shear stresses (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 318-323 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A special stress measuring device for determining the normal and shear stresses acting on silo walls was developed and tested. The load cell can be used for measuring simultaneously the normal stress as well as the intensity and direction of the shear stress.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120144
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    Modelling and simulation of monopropellant hydrazine thrusters for spacecraft position controlDedicated to Professor Dr. Dr. h.c. Ewald Wicke on the occasion of his 75th birthday (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 426-432 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Modelling of the kinetics of a 20-N hydrazine thruster is carried out by considering two different heterogeneous reaction channels for hydrazine decomposition to the intermediate ammonia. The parameters of the reactor model are estimated by making use of temperature profiles at the wall of the decomposition chamber. Simulated ageing of the catalyst revealed an increase of the rate of deactivation with increasing total firing time.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120161
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    Synthesis and X-ray characterization of double oxides of the formula Cr1-xW1+xO4 (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 153-157 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Darstellung und röntgenographische Charakterisierung von Doppeloxiden der Formel Cr1-xW1+xO4Mixed-Valenz-Verbindungen der Formel Cr1-xW1+xO4 wurden bei 1300°C dargestellt. Aus Röntgenbeugungsdiagrammen konnten drei verschiedene Phasen identifiziert werden, eine vom Rutiltyp für 0,40 ≤ x ≤ 0,50 und zwei andere mit Rutil-ähnlichen Strukturen bzw. vom CrWO4-Typ für 0 ≤ x ≤ 0,25 und vom WO2-Typ für 0,80 ≤ x ≤ 1.
    Notes: Mixed valency compounds of formula Cr1-xW1+xO4 have been prepared at 1300°C. Three phases have been identified by X-ray diffraction: one of rutile type for 0.40 ≤ x ≤ 0.50 and two others with rutile-related structures, i. e. of CrWO4-type for 0 ≤ x ≤ 0.25 and of WO2-type for 0.80 ≤ x ≤ 1.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895690116
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    Dihalogen(pentafluorphenyl)sulfonium(IV)-hexafluoroarsenat C6F5SX2+AsF6- (X = Cl, Br) und Kristallstruktur von Di(pentafluorphenyl)sulfan (C6F5)2S (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 158-168 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dihalogen(Pentafluorophenyl)sulfonium(IV) Hexafluoroarsenate C6F5SX2+AsF6- (X = Cl, Br) and Crystal Structure of Di(pentafluorophenyl)sulfane (C6F5)2SThe preparation and spectroscopic characterisation of the halogensulfonium salts C6F5SCl2+AsF6- and C6F5SBr2+AsF6- is reported. The new salts are much more stable than their trifluoromethyl derivatives.In addition the crystal structure of (C6F5)2S is reported. Space group P43212, Z = 4, 478 unique observed diffractometer data, Rint. = 0.07, lattice constants: a = 569.0(5) pm, c = 3785.8(22) pm, V = 1225 times; 10-30 m3.
    Notes: Es wird über die Darstellung und spektroskopische Untersuchung der Sulfoniumsalze C6F5SCl2+AsF6- und C6F5SBr2+AsF6- berichtet. Die neuen Salze sind bedeutend stabiler als ihre Trifluormethyl-Homologen.Ergänzend wird die Kristallstruktur von (C6F5)2S mitgeteilt. Raumgruppe P43212, Z = 4, 478 unabhängige Reflexe, Rint. = 0,07, Gitterkonstanten: a = 569,0(5) pm, c = 3785,8(22) pm, V = 1225×10-30 m3.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895690117
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    Berichtigung (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 192-192 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895690121
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    Complex copper(II) fluorides. X. The ternary system BaF2—CuF2—InF3 (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 169-176 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Komplexe Kupfer(II)-fluoride. X. Das ternäre System BaF2—CuF2—InF3Das flüssig-fest-Gleichgewichtsdiagramm des InF3—BaF2-Systems wird mittels DTA bestimmt. Die Fluoride BaInF5, das dimorphe Ba3In2F12 und auch eine kubische Phase Ba1-xInxF2+x, deren Struktur sich von der des BaF2 ableitet, wurden gefunden. Die zwei Formen des Ba3In2F12 geben feste Lösungen. Ein isothermer Ausschnitt des ternären Systems BaF2—CuF2—InF3 bei 540°C wird angegeben. Er zeigt die Existenz nur eines quaternären Fluorides: tetragonales BaCuInF7.
    Notes: The liquid-solid equilibria diagram of the InF3—BaF2 system is established by D.T.A. The fluorides BaInF5, the dimorphic Ba3In2F12, and also a cubic phase Ba1-xInxF2+x, the structure of which derives from that of BaF2, are disclosed. The two forms of Ba3In2F12 give solid solutions. An isothermal section of the ternary system BaF2—CuF2—InF3 at 540°C is given. It shows the existence of only one quaternary fluoride: tetragonal BaCuInF7.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895690118
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    Zum chemischen Transport von Chrom- und Manganmonophosphid mit Iod - Experimente und Modellrechnungen (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 192-192 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895690122
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    Beiträge zur Chemie N-organylsubstituierter Metallamide. XIX. Umsetzung von [Co(NPh2)2]2 mit CO - ein neuer Weg zur Synthese eines Innerkomplexes des Cobalt(II) mit einem Anthranilsäurederivat; Molekularstruktur von [Co(NPh(o—C6CONPh2))2] (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 183-191 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of N-substituted Metal Amides. XIX. Reaction of [Co(NPh2)2]2 with CO - a New Way for the Synthesis of an Chelate Complex of Cobalt (II) with an Derivative of Anthranilic Acid; Molecular Structure of [Co(NPh(o—C6H4CONPh2))2]Reaction of CO (1 atm, room temperature) with [Co(NPh2)2]2 (I) in benzene (mole ratio 3 : 1) gives Co(CO)3(NPh2)4(benzene)1·6 (II). By adding more CO to the reaction mixture (mole ratio 6 : 1) Co4(CO)12 (III) and a dark red compound of the analytical composition C50H38CoN4O2 (IV) could be isolated. The structure of the red compound was determined by X-ray diffraction. This investigation show IV to be a cobalt(II) complex of an derivative of the anthranilic acid, [Co(NPh(o—C6H4CONPh2))2] (IV). The cobalt coordination in this compound is a distorted tetrahedron. Crystal data of IV: space group P1 with a = 12.449(1) Å, b = 12.431(1) Å, c = 13.223(1) Å, α = 95.47(1)°, β = 95.37(1)°, γ = 94.10(1)°, and Z = 2.
    Notes: Bei der Umsetzung von CO (1 atm, Raumtemperatur) mit [Co(NPh2)2]2 (I) in Benzen im Molverhältnis 3 : 1 entsteht Co2(CO)3(NPh2)4(benzen)1,6 (II); im Molverhältnis 6 : 1 bildet sich ein Reaktionsgemisch, aus dem Co4(CO)12 (III) sowie eine dunkelrote Verbindung der analytischen Zusammensetzung C50H38CoN4O2 (IV) isoliert werden kann. Die Röntgenstruktur-bestimmung von IV ergab, daß es sich um den ein Anthranilsäurederivat als Liganden enthaltenden Komplex [Co(NPh(o—C6H4CONPh2))2] IV handelt, der eine verzerrt tetraedrische Koordination aufweist.Kristalldaten für IV: Raumgruppe P1 mit a = 12,449(1) Å, b = 12,431(1) Å, c = 13,223(1) Å, α = 95,47(1)°, β = 95,37(1)°, γ = 94,10(1)° und Z = 2.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895690120
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    Formation and transformation of δ-Nb2O5 solid solutions in the system Nb2O5—Al2O3 (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 177-182 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Bildung und Umwandlung von festen Lösungen des δ-Nb2O5 im Nb2O5—Al2O3-SystemIm System Nb2O5—Al2O3 werden (bis 50 Mol-% Al2O3) mit metastabilem, hexagonalem δ-Nb2O5 feste Lösungen gebildet, bei der Präparation aus den amorphen Substanzen, die durch simultane Hydrolyse von Niob- und Aluminiumalkoxid erhalten werden. Die Werte des Gitterparameters a sind unabhängig von der Zusammensetzung, während der Parameter c linear abnimmt mit steigendem Al2O3-Gehalt. Der übergang δ-Nb2O5 (orthorhombisch) erfolgt bei 640°C bis 700°C. Die 50 Mol-% Al2O3-enthaltende feste Lösung geht bei 800° bis 860°C in monoklines NbAlO4 über.
    Notes: In the system Nb2O5—Al2O3, solid solutions of metastable δ-Nb2O5 (hexagonal) are formed up to 50 mol% Al2O3 from amorphous materials prepared by the simultaneous hydrolysis of niobium and aluminium alkoxides. The values of the lattice parameter a are relatively constant regardless of composition, while parameter c decreases linearly with increasing Al2O3 content. The δ- to γ-Nb2O5 (orthorhombic) transformation occurs at ≍ 640°C to ≍ 700°C. The solid solution containing 50 mol% Al2O3 transforms to monoclinic NbAlO4 at 800° to 860°C.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895690119
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    Masthead (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 570 (1989) 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895700101
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    Die Reaktion des tert.Butyl-lithiums mit Aluminiumtribromid; Molekülstrukturen von [HAl(CMe3)2]3 und [LiHAl(CMe3)3]2 (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 570 (1989), S. 37-53 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reaction of tert.Butyl-lithium with Aluminiumtribromide; Molecular Structures of [HAl(CMe3)2]3 and [LiHAl(CMe3)3]2The reaction of tert.butyl-lithium with aluminiumtrihalide at low temperatures was reinvestigated. Four compounds were isolated: trimeric di(tert.butyl)alane(III) 1, monomeric (solution in benzene)/dimeric (solid state) lithium-tri(tert.butyl)alanate(III) 2, tri(tert.butyl)alane 3 and lithium-tetra(tert.butyl)alanate 4. X-ray structure analyses gave a planar sixmembered Al—H heterocycle for 1 and a Li—H-bridged dimer showing intramolecular interactions of lithium with C—H σ-bonds for 2.
    Notes: Die Reaktion des tert.Butyl-lithiums mit Aluminiumtrihalogenid bei tiefen Temperaturen wurde neu untersucht. Dabei isolierten wir: das trimere Di(tert.butyl)alan(III) 1, das monomere (benzolische Lösung)/dimere (Festkörper) Lithium-tri(tert.butyl)alanat(III) 2 sowie Tri(tert.butyl)alan 3 und Lithium-tetra(tert.butyl)alanat 4. Die Röntgenstrukturanalyse ergab einen planaren sechsgliedrigen Heterozyklus aus Al—H-Einheiten für 1 und ein über Li—H-Brücken verknüpftes Dimeres mit intramolekularen Wechselwirkungen zwischen den Lithiumatomen und C—H-σ-Bindungen für 2.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895700103
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    Zur Kenntnis von Ammonium-pentanitratopraseodymat und -neodymat (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 106-110 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Ammonium Pentanitrato Praseodymate and Neodymate(NH4)2[Pr(NO3)5] · 4 H2O (I) and (NH4)2[Nd(NO3)5] · 4 H2O (II) were obtained from Pr6O11 and Nd2O3 by reaction with nitric acid and NH4NO3. The fixed water molecules could be removed completely with formation of [NH4]2[Pr(NO3)5] (III) and [NH4]2[Nd(NO3)5] (IV). The i.r. spectra indicate only symmetrically bonded bidentate NO3- ligands. The water molecules are bonded as well by hydrogen bridges to NH4+ ions as by EDA interaction to the lanthanoid atoms. Therefore, the constitution of the complexes is described more exactly by the formula [NH4]2[Ln(NO3)5(H2O)2] · 2 H2O.
    Notes: (NH4)2[Pr(NO3)5] · 4 H2O (I) und (NH4)2[Nd(NO3)5] · 4 H2O (II) lassen sich durch Umsetzung von Pr6O11 bzw. Nd2O3 mit Salpetersäure und Ammoniumnitrat erhalten. Beide Komplexe ließen sich vollständig dehydratisieren unter Bildung von [NH4]2[Pr(NO3)5] (III) bzw. [NH4]2[Nd(NO3)5] (IV). Die Auswertung der IR-Spektren zeigt, daß in den Komplexen ausschließlich zweizähnig gebundene Nitratliganden vorliegen. I und II enthalten unterschiedlich gebundene Wassermoleküle, die teils über Wasserstoffbrücken an die NH4-Ionen, teils koordinativ an die Lanthanoidatome gebunden sind. Die Konstitution dieser Komplexe wird deshalb exakter durch die Formel [NH4]2[Ln(NO3)5(H2O)2] · 2 H2O beschrieben.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895690110
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    Über die Reaktionen von N-Chloracetonimin mit Molybdänpentachlorid und Wolframhexachlorid Die Kristallstruktur von Me2C=NH2[MoOCl4] (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 83-90 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of N-Chloroacetoneimine with Molybdenum Pentachloride and Tungsten Hexachloride. Crystal Structure of Me2C=NH2[MoOCl4]WCl6 reacts with N-chloroacetoneimine under elimination of chlorine and formation of pentachloro-isopropylideneimino-tungsten(VI), Cl5W=N=CMe2, a brown-black crystal powder, which was characterized by i.r. spectroscopy. MoCl5 reacts in a similar way, although only a product mixture can be obtained. Partial hydrolysis of this mixture yields isopropylideneiminium-tetrachlorooxomolybdate(V), Me2C=NH2+[MoOCl4]-, of which the crystal structure was determined (2323 unique observed reflexions, R = 0.049). Space group P21/c, Z = 4, a = 878.6, b = 907.2, c = 1252.2 pm, β = 91.29°. The compound consists of Me2C=NH2+ ions with a planar arrangement of the skeletal atoms and a CN bond length of 126.7 pm and of dimeric, centrosymmetric anions [MoOCl4]22- having Mo atoms linked via asymmetric chloro bridges (MoCl distances 238.4 and 307.6 pm). The longer Mo—Cl contacts are located in the trans-positions of the terminal oxoligands (MoO distance 164 pm).
    Notes: WCl6 reagiert mit N-chloracetonimin unter Chlorabspaltung und Bildung von Pentachlor(isopropylidenimido)wolfram(VI), Cl5W=N=CMe2, einem schwarzbraunen Kristallpulver, das durch sein IR-Spektrum charakterisiert wird. ähnlich verläuft die Umsetzung mit MoCl5, wobei allerdings kein einheitliches Produkt isoliert werden kann. Durch partielle Hydrolyse entsteht aus diesen Produkten Isopropylideniminiumtetrachloro-oxomolybdat(V), Me2C=NH2+[MoOCl4], von dem wir eine Kristallstrukturanalyse angefertigt haben (2323 unabhängige beobachtete Reflexe, R = 4,9%). Raumgruppe P21/c, Z = 4, Gitterabmessungen: a = 878,6; b = 907,2; c = 1252,2 pm; β = 91,29°. Die Verbindung besteht aus Kationen Me2C=NH2+, deren Gerüstatome in einer Ebene liegen und die eine CN-Bindungslänge von 126,7 pm haben, sowie zentrosymmetrischen dimeren Anionen [MoOCl4]22-, deren Mo-Atome über asymmetrische Chlorobrücken mit Mo—Cl-Abständen von 238,4 pm und 307,6 pm verknüpft sind. Die langen Mo—Cl-Kontakte befinden sich in trans-Stellung zu den terminal gebundenen Oxoliganden (Abstand MoO = 164 pm).
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895690107
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    Bindungsverhältnisse in kristallinen Phasen von Caesiumhydrogensulfid, CsHS und CsDS (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 117-130 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chemical Bonding in Crystalline Phases of Cesium Hydrogensulfides, CsHS and CsDSReaction of liquid hydrogensulfide, H2S and D2S respectively, with cesium at room temperature in pressure resistant glass tubes quickly gives the crystalline hydrosulfides, CsHS and CsDS. The compounds are characterized by thermochemical, X-ray, and neutron diffraction data.Three solid phases of CsDS are observed as a function of temperature: Changes in chemical bonding are discussed with respect to temperature and in comparison with alkali metal hydroxides, amides, halides, and further hydrogensulfides.
    Notes: Flüssiger Schwefelwasserstoff, H2S bzw. D2S, reagiert bei Raumtemperatur in druckfesten Glasgefäßen schnell mit Caesium, wobei kristallines Caesiumhydrogensulfid, CsHS bzw. CsDS entsteht. Thermochemische, Röntgen- und Neutronenbeugungsdaten charakterisieren die Verbindungen. Drei feste Phasen von CsDS wurden in Abhängigkeit von der Temperatur beobachtet: Änderungen der chemischen Bindung werden in Abhängigkeit von der Temperatur und durch Vergleich mit Alkalimetallhydroxiden, -amiden und -halogeniden sowie weiteren -hydrogensulfiden diskutiert.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895690112
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    Darstellung und Kristallstruktur von Lithiumhydrogensulfid, LiHS (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 111-116 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Crystal Structure of Lithiumhydrogensulfide, LiHSLithiumhydrogensulfide, LiHS, is prepared from lithiumamide, LiNH2, by reaction with liquid hydrogensulfide. At 150°C the solubility of LiHS in H2S is sufficient for the growth of single crystals in a temperature gradient within the autoclaves used. The X-ray structure determination at 295 K is characterized by the following data: \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{{{\rm P4}_{\rm 2} } \mathord{\left/ {\vphantom {{{\rm P4}_{\rm 2} } {{\rm mmc,\;Z = 2,\;a = 3.916}\left({\rm 2} \right){\AA},\;c = 6.155\left(2 \right){\AA},}}} \right. \kern-\nulldelimiterspace} {{\rm mmc,\;Z = 2,\;a = 3.916}\left({\rm 2} \right){\AA},\;c = 6.155\left(2 \right){\AA},}}} \hfill \\ {{\rm Z}\left({{\rm F}_{\rm 0}^{\rm 2} \ge 3\sigma \;{\rm F}_{\rm 0}^{\rm 2} } \right) = 74,\;{\rm R = 0.011}{\rm .}} \hfill \\\end{array} $$\end{document} Lithium occupies tetrahedral sites in a distorted cubic close-packed arrangement of S; in PtS sulfur occupies tetrahedral sites in a similar way in a distorted close packing of Pt. Hydrogen atoms of the HS--ions are dynamically disordered in a split position linearly bound to S. At 228 K a thermal effect occurs in DSC-measurements indicating that below this temperature the HS--ion has fixed positions.
    Notes: Zur Darstellung von Lithiumhydrogensulfid, LiHS, wurde Lithiumamid, LiNH2, in flüssigem Schwefelwasserstoff protolysiert. Bei 150°C reicht die Löslichkeit von LiHS in H2S für die Einkristallzüchtung im Temperaturgefälle von Autoklaven aus. Die röntgenographische Strukturbestimmung bei 295 K ist durch folgende Daten charakterisiert: \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{{{\rm P4}_{\rm 2} } \mathord{\left/ {\vphantom {{{\rm P4}_{\rm 2} } {{\rm mmc,\;Z = 2,\;a = 3,916}\left({\rm 2} \right){\AA},\;c = 6,155\left(2 \right){\AA},}}} \right. \kern-\nulldelimiterspace} {{\rm mmc,\;Z = 2,\;a = 3,916}\left({\rm 2} \right){\AA},\;c = 6,155\left(2 \right){\AA},}}} \hfill \\ {{\rm Z}\left({{\rm F}_{\rm 0}^{\rm 2} \ge 3\sigma\; {\rm F}_{\rm 0}^{\rm 2} } \right) = 74,\;{\rm R = 0,011}{\rm .}} \hfill \\\end{array} $$\end{document} In einer verzerrt kubisch flächenzentrierten Anordnung von S besetzt Li Tetraederlücken wie S in der ähnlich verzerrten Kugelpackung von Pt in PtS. Die Hydrogenatome der HS--Ionen sind in zwei linear über S verbundenen Positionen dynamisch fehlgeordnet. DSC-Messungen zeigen bei 228 K einen thermischen Effekt, der die Lagefixierung des HS--Ions vermuten läßt.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895690111
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    Quantenchemische Modellrechnungen zur Baugruppenwanderung in Hexafluorosilicaten (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 131-136 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Quantum Chemical Model Calculations on the Migration of Si—F Groups in HexafluorosilicatesThe transport of different Si—F species was simulated using two [SiF6]2- octahedra as example. Activation barriers and charge distributions were calculated with the EHT method.Bearing in mind the structure of cubic hexafluorosilicates calculations were carried out on the migration both along an edge and along a (110) face of the elementary cell. At first [SiF2]2+ and SiF4 groups were removed from an [Si2F12]4- unit to produce a surface vacancy. During a second step planar SiF4 groups were moved to the neighbouring lattice position.A diffusion of planar SiF4 is favoured, if the electrostatic interaction between moved and fixed fluorine atoms is as small as possible.
    Notes: Das EHT-Verfahren wurde genutzt, um am Beispiel von zwei [Sif6]2--Baueinheiten den Transport verschiedener SiF-Spezies zu simulieren und dabei die auftretenden Aktivierungsbarrieren und Ladungsverteilungen zu berechnen. Ausgehend von der Struktur kubischer Alkalihexafluorosilicate wurden Rechnungen zum Transport entlang der Kante und entlang einer (110)-Fläche der Elementarzelle durchgeführt. Dabei wurden zunächst [SiF2]2+- bzw. SiF4-Gruppen aus dem [Si2F12]4--Verband zur Schaffung eines freien Oberflächenplatzes entfernt. In einem zweiten Schritt wurden im Modell [SiF8]4- planare SiF4-Gruppen zum jeweils benachbarten Gitterplatz transportiert.Der Transport eines [SiF2]2+-Moleküls erfordert einen wesentlich höheren Energieaufwand als der Transport von planarem SiF4. Eine Diffusion von planarem SiF4 wird begünstigt, wenn eine möglichst geringe elektrostatische Wechselwirkung zwischen den bewegten und feststehenden Fluoratomen stattfindet.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895690113
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    Struktur und Eigenschaften quaternärer Chalkogenide MIAIIIBIVX4VI. III. Über die Verbindungen AgTiZrTe4 und Ag2TiZrTe4 (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 145-152 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Structure and Properties of Quaternary Chalcogenides MIAIIIBIVX4VI. III. On the Compounds AgTiZrTe4 and Ag2TiZrTe4Preparation and properties of the compounds AgTiZrTe4 and Ag2TiZrTe4 are reported. The structure deduced from X-ray diffraction diagrams is closely related to the structure of TiZrTe4 showing an ordered accomodation of Ti and Zr atoms at the octahedral sites of the CdI2 type structure. The interlayers free of Ti and Zr atoms are suggested to be in part occupied by Ag+ ions in an ordered sequency, which allows to explain the occurrence of 8 Te layers in the repeating unit.
    Notes: Es wird über die Darstellung der Verbindungen AgTiZrTe4 und Ag2TiZrTe4 und deren Eigenschaften berichtet. Röntgenpulverdiffraktogramme lassen auf enge strukturchemische Beziehungen zum TiZrTe4 mit geordneter Verteilung der Ti- und Zr-Atome auf den Oktaederplätzen des CdI2-Strukturtyps schließen. Für die Ag+-Ionen wird eine partielle Besetzung der Tetraederlücken in den von Ti- bzw. Zr-Atomen freien Zwischenschichten in geordneter Abfolge in Betracht gezogen, die das Auftreten von 8 Te-Schichten in der Wiederholungseinheit erklärt.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895690115
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    Über Chalkogenolate. 191. Ester der 2-Oxophenyldithioessigsäure 2. Kristall- und Molekülstruktur des Methylesters (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 569 (1989), S. 137-144 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Chalcogenolates. 191. Esters of 2-Oxophenyldithioacetic Acid. 2. Crystal and Molecular Structure of the Methyl EsterThe title compound C6H5—CO—CS—SCH3 crystallizes with Z = 2 in the triclinic space group P1 with cell dimensions (-60°C) a = 6.236(4) Å, b = 7.972(2) Å, c = 9.589(4) Å, α = 88.42(3)°, β = 75.39(5)°, γ = 81.54(4)°. The structure has been determined from single crystal X-ray data measured at -60°C and refined to R = 0.085 and Rw = 0.087 for 2307 independent reflections. With nearly 20° the C=O bond is turned out of the plane of the phenyl ring.
    Notes: Die Titelverbindung C6H5—CO—CS—SCH3 kristallisiert triklin mit Z = 2 in der Raumgruppe P1 mit den Gitterdimensionen (-60°C) a = 6,236(4) Å, b = 7,972(2) Å, c = 9,589(4) Å, α = 88,42(3)°, β = 75,39(5)°, γ = 81,54(4)°. Die Kristallstruktur wurde aus bei -60°C vermessenen röntgenographischen Einkristalldaten unter Verwendung von 2307 symmetrieunabhängigen Reflexen bestimmt und bis auf Zuverlässigkeitsfaktoren von R = 0,085 und Rw = 0,087 verfeinert. Im Molekül ist die C=O-Bindung etwa 20° aus der Ebene des Phenylrings herausgedreht.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895690114
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    Crystal structure of cadmium cyclohexaphosphate hexahydrate: Cd3P6O18 · 6 H2O (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 570 (1989), S. 138-144 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Darstellung und Kristallstruktur eines Cadmiumcyclohexaphosphates: Cd3P6O18 · 6 H2OEs werden die Darstellung und die Kristallstruktur von Cd3P6O18 · 6 H2O beschrieben. Die Verbindung besitzt trigonale (rhomboedrische) Symmetrie, die Elementarzellendaten sind: \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{\rm a}_{\rm H} = 15.056(10)} & {{\rm c}_{\rm H} = 16.080(10){\rm }{\AA}} \\ \end{array} $$\end{document} oder \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{\rm a}_{\rm R} = 10.212(10){\rm }{\AA}} & {{\rm \alpha }_{\rm R} = 94.98}\deg \\ \end{array} $$\end{document}Die Raumgruppe ist R3 mit Z = 6 in der hexagonalen Aufstellung. Die Kristallstruktur wurde mit Hilfe von 1355 unabhängigen Reflexen bis zu einem R-Wert von 0,013 bestimmt. Die P6O18-Ringanionen weisen eine dreizähnige Symmetrie auf. Das Cadmium-Koordinationspolyeder ist ein leicht verzerrtes Oktaeder, das von vier Sauerstoff-Atomen und zwei Wassermolekülen gebildet wird. Die Wassermoleküle verknüpfen diese Oktaeder zu Sechsringen mit der Symmetrie 3, diese Ringe wechseln sich entlang der 3-Achse mit den P6O18-Ring-Anionen ab.
    Notes: Chemical preparation and crystal structure of Cd3P6O18 · 6 H2O are described. This compound is trigonal (rhomboedral) with the following unit-cell dimensions: \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{\rm a}_{\rm h} = 15.056(10)} & {{\rm c}_{\rm h} = 16.080(10){\rm }{\AA}} \\ \end{array} $$\end{document} or \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{\rm a}_{\rm r} = 10.212(10){\rm }{\AA}} & {{\rm \alpha }_{\rm r} = 94.98}\deg \\ \end{array} $$\end{document}The space group is R3 with Z = 6 for the hexagonal description. The crystal structure has been solved by using 1355 unique reflexions with a final R value 0.013.The P6O18 ring anions have a threefold symmetry. The cadmium coordination polyhedron is a slightly distorted octahedron built up by four oxygen atoms and two water molecules. The water molecules link themselves as to build six-member rings having a 3 symmetry alterning with the P6O18 phosphoric rings along the 3 axes.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895700114
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    Transition metal Complexes with the Thiosemicarbazide-based Ligands. VI. Nickel and zinc complexes with S-alkylisothiosemicarbazides (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 570 (1989), S. 167-176 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Übergangsmetall-Komplexe mit Thiosemicarbazid-Liganden. VI. Komplexe von NiII und ZnII mit S-AlkylisothiosemicarbazidDurch Umsetzung der ethanolischen Lösung von Ni(OAc)2 · 4 H2O mit S-Alkylisothiosemicarbazid-Iodwasserstoff (L—R · HI; R = Me, Et, n-Pr, n-Bu) und Pyridin wurden die oktaedrischen Bisligand-Komplexe der allgemeinen Formel [Ni(L—R)2Py2]I2 erhalten. Durch Erhitzen bei 95°C bzw. 110°C wurden die Komplexe in die quadratisch-planaren [Ni(L—R)2]I2 (R = Me, Et) - und [Ni(L—R)2I2] (R = n-Pr, n-Bu) - Komplexe mit verzerrt-oktaedrischer Konfiguration überführt. Ferner wurde in ethanolischer Lösung Zn(L—Me)2I2 dargestellt. Die Verbindungen wurden durch Elementaranalyse, TG, magnetische und spektroskopische Messungen charakterisiert.
    Notes: The reaction of warm ethanolic solution of Ni(OAc)2 · 4 H2O with S-alkylisothiosemicarbazide-hydrogeniodide (L—R · HI; R = Me, Et, n-Pr, n-Bu) and pyridine yielded the octahedral bis(ligand) complexes of the general formula [Ni(L—R)2Py2]I2. By the isothermal heating at 95 and 110°C, these complexes were transformed into the square-planar [Ni(L—R)2]I2 (R = Me, Et) complexes and the [Ni(L—R)2I2] (R = n-Pr, n-Bu) complexes of distorted octahedral configuration. Besides, the Zn(L—Me)2I2 complex was prepared. The compounds have been characterized by elemental analysis, magnetic measurements, diffuse reflectance spectra and TG analysis.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895700118
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    Structure of molten systems KF—K2TiF6 and KCL-K2TiF6 (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 570 (1989), S. 184-192 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Struktur der geschmolzenen Systeme KF—K2TiF6 und KCl—K2TiF6Die kongruent schmelzenden Verbindungen K3TiF7 und K3TiF6Cl, die in den Systemen KF—K2TiF6 bzw. KCl—K2TiF6 gebildet werden, zeigen einen starken Einfluß auf die Struktur (ionische Zusammensetzung) der Schmelzen der entsprechenden Systeme. In Anbetracht der relativ niedrigen Symmetrie und des hohen Energiezustandes der TiF73-- und TiF6Cl3--Ionen, sollte für sie ein hoher thermischer Dissoziationsgrad erwartet werden. Diese Annahme wird durch zwei verschiedene Methoden - die thermodynamische Analyse der Phasengleichgewichte und der Volumeneigenschaften bestätigt. Die Werte der Schmelzenthalpie für K2TiF6, K3TiF7 und K3TiF6Cl, die zu den Berechnungen verwendet werden, wurden ebenfalls bestimmt.
    Notes: Congruently melting compounds K3TiF7 and K3TiF6Cl which are formed in the systems KF—K2TiF6 and KCl—K2TiF6, respectively, exhibit a strong influence on the structure (ionic composition) of the melts of the corresponding systems. Considering the relatively low symmetry and a high energetic state of the TiF73- and TiF6Cl3- complex ions, a high degree of their thermal dissociation might be expected. This assumption was confirmed by two different methods based on a thermodynamic analysis of the phase equilibria and of the volume properties of the investigated systems, respectively. In connection with the former method, the values of the enthalpy of fusion of K2TiF6, K3TiF7, and K3TiF6Cl which were used in the calculations have also been estimated.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895700120
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    Experimente zur Mischkristallbildung zwischen Zinktantalaten und -antimonaten: ZnTa2-xSbxO6 und Zn4Ta2-xSbxO9 (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 568 (1989), S. 22-28 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Experiments about the Mixed Crystal Formation between Zincoxotantalates and -antimonates: ZnTa2-xSbxO6 and Zn4Ta2-xSbxO9In the area of substituted oxotantalates of zinc two new phases of the composition A: ZnTa1·8Sb0·2O6 and B: Zn4Ta1·2Sb0·8O9 were prepared and investigated by X-ray single crystal technique. A crystallizes with tetragonal symmetry (space group D4h14-P42/mnm, a = 4.7314; c = 9.2160 Å; Z = 2). B is monoclinic (space group C2h6-C2/c; a = 15.103; b = 8.839; c = 10.378 Å; β = 93.81°; Z = 8). A crystallizes with trirutile structure, although there is a small replacement of Ta5+ by Sb5+. B maintains the Zn4Ta2O9 structure. One of the point positions of the M5+ ions is occupied statistically by Ta5+/Sb5+ and Zn2+. B is a metastable compound.
    Notes: Im Bereich substituierter Oxotantalate des Zinks wurden zwei neue Phasen A: ZnTa1,8Sb0,2O6 und B: Zn4Ta1,2Sb0,8O9 an Einkristallen röntgenographisch untersucht. A kristallisiert tetragonal (Raumgruppe D4h14-P42/mnm, a = 4,7314; c = 9,2160 Å; Z = 2), B monoklin (Raumgruppe C2h6-C2/c, a = 15,103; b = 8,839; c = 10,378 Å; β = 93,81°; Z = 8). A kristallisiert trotz des geringen Ersatzes von Ta5+ gegen Sb5+ im Trirutiltyp. B behält die Struktur von Zn4Ta2O9 bei. Eine Position der oktaedrisch koordinierten M5+-Ionen ist mit Zn2+ statistisch besetzt. B ist metastabil.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895680104
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    Ein Oxowolframat mit „Kanalstruktur“: KNa3WO5 (Mit einer Bemerkung über den Aufbau von Na4WO5) (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 143-156 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: An Oxotungstate with „Channel Structure“: KNa3WO5 (With a Remark on Na4WO5)For the first time single crystals of Na4WO5 were prepared by heating of annealing mixtures of Na2WO4 [2] and Na2O [Na:W = 4,2:1, Ni-cylinder, 725°C, 28 d]. Four-circle-diffraktometer data [PW 1100, 1900 IO(hkl), ω-2Θ scan, AgKα-radiation, R = 6,5%, RW = 5,7%] determine the triclinic structure of Na4WO5 with a = 569.4(2), b = 847.7(2), c = 565.7(1) pm, α = 101.29(2)°, β = 102.25(3)°, γ = 109.20(3)°. It is isotypic with the NaCl-type of structure Li4WO5. By heating Na4WO5 with K2O [Na:K:W = 4:3:1, Au-tube, 750°C, 35 d] colourless single crystals of KNa3WO5 were obtained for the first time. The structure determination [four-circle-diffraktometer data, PW 1100, ω-2Θ scan, 943 IO(hkl), MoKα-Strahlung R = 4.9%, RW = 3.9%] proves space group C2/m with a = 907.8(3), b = 753.9(2), c = 911.8(3) pm, β = 104.07(4)°, Z = 4. The structure is characterised by undulating layers of Na, W and O and two different kinds of channels.The Madelung Part of Lattice Energie, MAPLE, Effective Coordination Numbers, ECON, these via Mean Fictive Ionic Radii, MEFIR, are calculated and discussed.
    Notes: Neu dargestellt wurden farblose Einkristalle von Na4WO5 durch Tempern inniger Gemenge von Na2WO4 [2] und Na2O [Na:W = 4,2:1, Ni-Bömbchen, 725°C, 28 d]. Nach Vierkreisdiffraktometerdaten [PW 1100, 1900 IO(hkl), ω-2Θ-scan, AgKα-Strahlung, R = 6,5%, RW = 5,7%] kristallisiert Na4WO5 triklin mit a = 569,4(2), b = 847,7(2), c = 565,7(1) pm, 101,29(2)°, β = 102,25(3)°, γ = 109,20(3)°, Z = 2. Es ist isotyp mit der Kochsalzvarianten Li4WO5.Durch Erhitzen von Na4WO5 im Gemenge mit K2O [Na:K:W = 4:3:1, Au-Rohr, 750°C, 35 d] wurden erstmals farblose Einkristalle von KNa3WO5 erhalten. Die Strukturaufklärung [Vierkreisdiffraktometerdaten, PW 1100, ω-2Θ-scan, 943 IO(hkl), MoKα-Strahlung R = 4,9%, RW = 3,9%] belegt die Raumgruppe C2/m mit a = 907,8(3), b = 753,9(2), c = 911,8(3) pm, β = 104,07 (4)°, Z = 4. Der Aufbau ist durch gewellte Schichten aus Na, W und O und zwei verschiedene Sorten von Kanälen charakterisiert.Der Madelunganteil der Gitterenergie, MAPLE, Effektive Koordinationszahlen, ECON, diese über Mittlere Fiktive Ionenradien, werden berechnet und diskutiert.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895730115
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    Darstellung von CF3SClF+MF6- (M = As, Sb) und Kristallstruktur von CF3SCl2+SbF6- (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 185-194 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation of CF3SClF+MF6- (M = As, Sb) and Crystal Structure of CF3SCl2+SbF6-CF3SClF+MF6- (M = As, Sb) is prepared by oxidative fluorination of CF3SCl with XeF+MF6-. The new salt is characterized by IR, Raman and NMR spectra in comparison with CF3SF2+MF6- and CF3SCl2+MF6-. In SO2 solution CF3SClF+SbF6- symmetrizises into CF3SF2+SbF6- and crystalline CF3SCl2+SbF6- with the monoclinic space group P21/c with a = 773.5(14) pm, b = 954.8(15) pm, c = 1242.0(18) pm, β = 100.24(8)°, Z = 4.
    Notes: Die Darstellung von CF3SClF+MF6- (M = As, Sb) erfolgt durch oxidative Fluorierung von CF3SCl mit XeF+MF6-. Das Salz wird schwingungs- und NMR-spektroskopisch charakterisiert, orientierend an den bekannten Daten von CF3SF2+MF6- und CF3SCl2+MF6-. In einer SO2-Lösung symmetrisiert sich CF3SClF+SbF6- zu CF3SF2+SbF6- und einkristallinem CF3SCl2+SbF6- mit der monoklinen Raumgruppe P21/c, a = 773,5(14) pm, b = 954,8(15) pm, c = 1242,0(18) pm, β = 100,24(8)°, Z = 4.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895730118
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    Zwei neue Rubidiumlithiumzincate: RbLiZnO2 und RbLiZn2O3 (mit einer Bemerkung über CsLiZnO2) (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 568 (1989), S. 136-146 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Rubidium Lithium Zincates: RbLiZnO2 and RbLiZn2O3For the first time colourless single crystals of RbLiZnO2 (A) and RbLiZn2O3 (B) have been prepared. Both crystallize tetragonally, A: space group I4/mmm, Z = 2, a = 351.84(4), c = 1153.3(2) pm; B: space group P42/mnm, Z = 4, a = 1 033.8(1), c = 342.8(1) pm. The crystal structures have been determined from four circle diffractometer data (MoKα; A: 155 hkl, R = 7.9%, Rw = 7.6%; B: 384 hkl, R = 7.0%, Rw = 4.6%). RbLiZnO2 has the BaZn2P2 type of structure while RbLiZn2O3 exhibits a new structure type with linear chains of face shared cubes ∞1[O4/2RbO4/2RbO4/2] as characteristic feature. For both oxides the Madelung part of lattice energy (MAPLE), and effective coordination numbers (ECoN) are calculated.
    Notes: Neu dargestellt wurden die Oxide RbLiZnO2 (A) und RbLiZn2O3 (B) in Form farbloser Einkristalle durch Tempern entsprechender Gemenge der binären Oxide. Beide Zincate kristallisieren tetragonal, A: Raumgr. I4/mmm, Z = 2, a = 351,84(4), c = 1153,3(2) pm; B: Raumgr. P42/mnm, Z = 4, a = 1 033,8(1), c = 342,8(1) pm. Die Kristallstrukturen wurden aus Vierkreisdiffraktometerdaten (MoKα) bestimmt (A: 155 hkl, R = 7,9%, Rw = 7,6%; B: 384 hkl, R = 7,0%, Rw = 4,6%). RbLiZnO2 kristallisiert im BaZn2P2-Strukturtyp, RbLiZn2O3 zeigt eine neue Struktur mit charakteristischen Würfel-Doppelketten ∞1[O4/2RbO4/2RbO4/2]. Der Madelunganteil der Gitterenergie (MAPLE) sowie effektive Koordinationszahlen (ECoN) wurden jeweils berechnet.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895680116
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    Zur Kenntnis des α-NaFeO2-Types: Über KPrO2 [1] (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 568 (1989), S. 147-150 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the α-NaFeO2-Type: On KPrO2For the first time we obtained yellow-green single crystals of KPrO2 by annealing K2PrO3 in Ni-cylinders [1 000°C; 4 weeks]. The structure determination confirms the trigonal rhombohedral α-NaFeO2-type: a = 365.11(3), c = 1 859.65(21) pm, c/a = 5.09, Z = 3, spacegroup R3m, fourcircle diffractometer data (Philips PW 1100), MoKα, 134 Io(hkl), R = 2.58%, Rw = 2,42%.
    Notes: Erstmals erhielten wir gelbgrüne Einkristalle von KPrO2 durch Tempern von K2PrO3 in Ni-Bömbchen [1000°C; 4 Wochen]. Es liegt der trigonal-rhomboedrische α-NaFeO2 Typ vor: a = 365,11(3), c = 1 859,65(21) pm, c/a = 5,09, Z = 3, Raumgruppe R3m, Vierkreisdiffraktometerdaten (Philips PW 1100), MoKα, 134 Io(hkl), R = 2,58%, Rw = 2,42%.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895680117
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    Herstellung keramischer Pulver. II. Über die Bildung von Mg2TiO4, MgTiO3 und MgTi2O5 durch Hydrolyse von 2-Ethoxyethylaten (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 208-214 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation of Ceramic Powders. II. Mg2TiO4, MgTiO3, and MgTi2O5 Formed by Hydrolysis of 2-EthoxyethylatesSolutions of 2-ethoxyethylates of magnesium and titanium in 2-ethoxyethanol submitted to hydrolysis, evaporation and heating of the residue up to 450°C allow to prepare Mg2TiO4, MgTiO3, and MgTi2O5 in an amorphous state with smaller than 1% of volatile components. Highly dispersed powders showing an increased sintering activity are obtained as a result of recrystallization. Mg2TiO4 is formed as inverse spinel phase in a metastable state.
    Notes: Die 2-Ethoxyethylate von Magnesium und Titan bilden in 2-Ethoxyethanol stabile Lösungen, deren Hydrolyse nach dem Abdestillieren des Lösungsmittels und Erhitzen des Rückstandes bis auf 450°C die Herstellung von Mg2TiO4, MgTiO3 und MgTi2O5 im amorphen Zustand mit weniger als 1% flüchtigen Bestandteilen gestattet. Die Rekristallisation führt zu hochdispersen sinteraktiven Pulvern, im Fall von Mg2TiO4 zur Bildung der inversen Spinellphase unter metastabilen Bedingungen.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895730121
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    The electrochemical synthesis of neutral Nickel(II) Complexes of Schiff Base Ligands: The crystal structure of bis-{N-[2-(2-pyridyl)ethyl]salicylideneiminato}nickel(II) trihydrate (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 215-222 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Elektrochemische Synthese von neutralen Nickel(II)-Komplexen mit Schiffschen Basen: Kristallstruktur von Bis-{N-[2-(2-pyridyl) äthyl]-salicylideneiminato}nickel(II) TrihydratNickel(II)-Komplexe mit im Pyridin-Ring substituiertem N-2-(2-pyridyl)-äthyl-salicylideneiminat wurden durch Elektrolyse einer nicht wäßrigen Lösung des entsprechenden Liganden hergestellt; als Anode diente ein Ni-Draht. Die Struktur von Bis-{N-[2-(2-pyridyl)äthyl]-salicylideneiminato}nickel(II). Trihydrat wurde röntgenographisch bestimmt. Der Komplex kristallisiert triklin in der Raumgruppe P1 mit den Gitterkonstanten a = 13,055(4) Å, b = 13,097(6)Å, c = 16,189(5) Å, α = 102,92(3)°, β = 99,80(3)°, γ = 90,42(3)° und Z = 4. Eine Least-squares-Verfeinerung führte zu einem R-Wert von 0,047. Das Molekül ist nicht zentrosymmetrisch, da die zwei dreizähnigen Liganden eine meridionale Konfiguration um das oktaedrisch koordinierte Nickel(II) annehmen.
    Notes: Nickel(II) complexes with N-2-(2-pyridyl)ethyl-ring substituted salicylideneiminatos have been synthesized by an electrochemical procedure using a sacrificial anode in non-aqueous solution of the corresponding ligand. The structure of bis{N-[2-(2-pyridyl)]-salicylideneiminato}-nickel (II) trihydrate has been determined by X-ray diffraction. Crystals are triclinic, space group P1, with four formula units in a cell of dimensions a = 13.055(4) Å, b = 13.097(6) Å, c = 16.189(5) Å, and α = 102.92(3)°, β = 99.80(3)°, γ = 90.42(3)°. Full matrix least squares refinement on R converged with a conventional agreement factor of 0.047. The molecule is non-centrosymmetric with two terdentate ligands in a meridional configuration around octahedral nickel(II).
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895730122
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    Beiträge zur Untersuchung anorganischer nichtstöchiometrischer Verbindungen. XXXVIII. Quaternäre Nioboxidfluoride des Cadmiums und Mangans mit LiNb6O15F-Struktur (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 240-240 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895730125
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    Pollucite- and Leucite-related Phases: A2BX5O12 and ACX2O6 (A = K, Rb, Cs; B = Be, Mg, Fe, Co, Ni, Cu, Zn, Cd; C = B, Al, Ga, Fe, Cr; X = Si, Ge) (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 223-230 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Pollucit- und Leucit-verwandte Phasen: A2BX5O12 und ACX2O6 (A = K, Rb, Cs; B = Be, Mg, Fe, Co, Ni, Cu, Zn, Cd; C = B, Al, Ga, Fe, Cr; X = Si, Ge)Darstellung und kristallographische Daten von 29 neuen Phasen dieser Strukturfamilie werden angegeben. Ein Überblick über die gesamte Strukturfamilie, die bis jetzt 59 Phasen enthält, wird gegeben. Die Familie enthält wenigstens sieben Strukturvarianten, von denen zwei die Pollucit-, CsAlSi2O6, und Leucit-, KAlSi2O6, Struktur sind. Beziehungen zwischen der Kationengröße und dem Strukturtyp werden vorgestellt. Ungewöhnliche Variationen in den Größen der Einheitszelle als Funktion der Kationengröße werden diskutiert, und auf die mögliche Bedeutung für das „partially collapsed framework“-Konzept von Taylor und Henderson wird hingewiesen.
    Notes: Synthesis and crystallographic data on 29 new phases in this family are given. A survey of the crystal chemistry of the complete family, containing 59 phases to date, is presented. The family contains at least seven structural variations, two of which are the pollucite, CsAlSi2O6 and leucite, KAlSi2O6 structures. Correlations between cation size and structure type are presented. Unusual variations in unit cell dimensions as a function of cation size are discussed and the possible relevance of the „partially collapsed framework“ concept of Taylor and Henderson indicated.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895730123
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    Untersuchungen zur heterogen-katalysierten Ringalkylierung von Toluen mit Methanol an modifizierten ZSM-5-Zeolithen (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 231-239 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Studies of the Heterogeneous Catalytical Ring Alkylation of Toluene with Methanol on Modified Zeolites ZSM-5Various ways for controlling the catalytic activity, the shape selectivity, and the deactivation behaviour of modified zeolites ZSM-5 has been shown by the example of the heterogeneous catalytical conversion of toluene with methanol. The preferred formation of the industrially interesting para-xylene is possible by use of ZSM-5-zeolites composed of large crystals, by dealumination of the external surface after hydrothermal treatment, by poisoning of external active centres after impregnation with inorganic salts as well as by isomorphic incorporation of boron for silicon and/or aluminium in the zeolite framework.
    Notes: Am Beispiel der heterogen-katalysierten Umsetzung von Toluen mit Methanol wurden verschiedene Wege zur Steuerung der katalytischen Aktivität, der Formselektivität und des Desaktivierungsverhaltens modifizierter H-ZSM-5-Zeolithe aufgezeigt. Eine Ausprägung der bei der Toluenmethylierung technisch interessanten para-Xylen-Selektivität gelingt durch den Einsatz von großkristallinen ZSM-5-Zeolithen, durch Dealuminieren der äußeren Oberfläche mittels hydrothermaler Behandlung, durch Vergiften äußerer aktiver Zentren mittels Tränkung anorganischer Salze sowie durch den isomorphen Einbau von Bor für Silicium und/oder Aluminium im Zeolithgerüst.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895730124
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    Die Reaktion von Trichloracetyltrischwefeltrinitrid mit Molybdänpentachlorid. Die Kristallstrukturen von CCl3CO-NS3N2 und (PPh4)2[MoCl3(N2SCOCCl3)]2 · 2CH2Cl2 · 2CCl4 Z. anorg. allg. Chem. 562 (1988) 31 (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 240-240 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895730126
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    Synthese und Charakterisierung von Sulfinato-Nickel(II)-Komplexen (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 240-240 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895730127
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    Masthead (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 575 (1989) 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895750101
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    Günther Rienäcker zum Gedenken (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 575 (1989), S. 7-9 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895750102
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    Synthese, IR-Spektrum und Kristallstruktur von N,N'-Bis(trimethylsilyl)benzamidinium-tetrachloroferrat(III) (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 575 (1989), S. 10-16 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis, IR Spectrum, and Crystal Structure of N,N'-Bis(trimethylsilyl)benzamidinium Tetrachloroferrate(III)The title compound [C6H5—C(NHSiMe3)2][FeCl4] is obtained by the reaction of FeCl3 with N,N,N'-tris(trimethylsilyl)benzamidine in the presence of tetrahydrofurane, forming yellow, moisture sensitive crystals. The compound is characterized by its IR spectrum as well as by an X-ray structure determination. Space group P21/n, Z = 8, 5974 independent observed reflexions, R = 0.066. The lattice dimensions are at -70°C: a = 2110.7, b = 1109.5, c = 2120.4 pm; β = 111.17º. The compound forms ion pairs, in which the H atoms of the amidinium cation are coordinated with one chlorine ligand of the FeCl4- ion in a chelating manner.
    Notes: Die Titelverbindung [C6H5—C(NHSiMe3)2][FeCl4] entsteht in Form gelber feuchtigkeitsempfindlicher Kristalle bei der Einwirkung von Eisen(III)chlorid auf N,N,N'-Tris(trimethylsilyl)benzamidin in Gegenwart von Tetrahydrofuran. Die Verbindung wurde durch das IR-Spektrum und durch eine Kristallstrukturanalyse charakterisiert. Raumgruppe P21/n, Z = 8, 5974 unabhängige beobachtete Reflexe, R = 6,6%. Die Gitterkonstanten betragen bei -70°: a = 2110,7; b = 1109,5; c = 2120,4 pm; β = 111,17º. Die Verbindung bildet Ionenpaare, in denen die H-Atome des Amidiniumkations eines der Chloratome des FeCl4--Anions chelatartig umgeben.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895750103
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    Ni5HfB2O10 mit geordneter MetallverteilungProfessor Reginald Gruehn zum 60. Geburtstage am 6. Oktober 1989 gewidmet (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 575 (1989), S. 26-30 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ni5HfB2O10 with Ordered Metal DistributionNi5HfB2O10 was prepared for the first time and investigated by X-ray methods. It crystallizes with orthorhombic symmetry, space group D2h16 - Pnma, a = 9.328; b = 6.120; c = 12.334 Å; Z = 4. In opposition to the Ni5TiB2O10-type all metal point positions are strongly ordered. The authors are in doubt about the partly statistic metal distribution within Ni5M4+B2O10 (M4+ = Ti, Zr, Ge).
    Notes: Ni5HfB2O10 wurde erstmals dargestellt und an Einkristallen untersucht. Ni5HfB2O10 kristallisiert orthorhombisch, Raumgruppe D2h16 - Pnma, a = 9,328; b = 6,120; c = 12,334 Å, Z = 4. Im Gegensatz zum Ni5TiB2O10-Typ weist NiHfB2O10 eine total geordnete Metallverteilung auf. Die partiell statistische Verteilung von Ni2+ mit M4+ (M4+ = Ti, Zr, Ge) wird in Frage gestellt.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895750105
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    27Al-NMR-Untersuchungen an Alkalifluoroaluminaten (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 575 (1989), S. 17-25 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 27Al NMR Studies on Alkali FluoroaluminatesThe 27Al NMR spectra of the alkali fluoroaluminates sensitively reflect the kind of condensation of the AlF6 octahedra. Whereas the chemical shift of the octahedral Al is shown to be rather independent on structural details, clear differences in the electric field gradients of isolated and condensed AlF6 octahedra were found. In contrast to the isolated octahedra which show only weak effects of quadrupole interaction, both for chains and layers of AlF6 octahedra axial EFG tensors result with quadrupolar coupling constants of between 10 and 13 MHz; for the threefold chains in CsAlF4 only a value of 7.5 MHz is obtained.
    Notes: Die 27Al-NMR-Spektren der Alkalifluoroaluminate spiegeln in empfindlicher Weise die Verknüpfung der AlF6-Oktaeder wider. Während sich die chemische Verschiebung für das oktaedrisch koordinierte Aluminium als nahezu unbeeinflußt von strukturellen Details erweist, ergeben sich deutliche Unterschiede in den elektrischen Feldgradienten (EFG) zwischen isolierten und verknüpften AlF6-Oktaedern. Im Gegensatz zu den isolierten Oktaedern, bei denen Quadrupolwechselwirkungseffekte nur eine untergeordnete Rolle spielen, ergeben sich sowohl für Ketten als auch schichtförmige Verknüpfung der AlF6-Oktaeder axiale EFG-Tensoren mit Quadrupolkopplungskonstanten zwischen 10 und 13 MHz, bei Verknüpfung als Dreierstrangkette im CsAlF4 lediglich ein Wert von 7,5 MHz.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895750104
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...