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  • 1
    Electronic Resource
    Electronic Resource
    The economic evaluation of the electrochemical o-nitrotoluene/o,o-azoxytoluene reduction process (1983)
    Springer
    Journal of applied electrochemistry 13 (1983), S. 637-649 
    Details
    ISSN: 1572-8838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Notes: Abstract o-Tolidine, obtained by the reduction of o-nitrotoluene, is used in the production of azo-dyestuffs. The electrochemical reduction of nitrotoluene has to take place in two steps. A continuous process is proposed for the first step, i.e., the electrochemical reduction of o-nitrotoluene to o,o-azoxytoluene in an alkaline ethanol-water solution. Azoxytoluene is separated from the catholyte by crystallization and filtration. The solution, obtained after the isolation of azoxytoluene is regenerated by distillation. A general method is outlined to calculate the overall production costs for the proposed process since it is representative of electroorganic processes with two consecutive separation processes. The method is illustrated by the calculation of the costs of an azoxytoluene production of 5 kg h−1 as a function of the catholyte composition and the chemical yield. An economic optimization is performed to design the process at the minimum costs. The calculations show that the optimum electrolysis conditions are strongly influenced by the additional processes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00617821
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  • 2
    Electronic Resource
    Electronic Resource
    196. Langzeitergebnisse der Knieprothese nach Blauth (1981)
    Springer
    Langenbeck's archives of surgery 355 (1981), S. 559-559 
    Details
    ISSN: 1435-2451
    Keywords: Knee-hinge prosthesis ; Long-term follow-up ; Complications ; Kniegelenksscharnierprothese ; Langzeitergebnisse ; Komplikationen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Kniegelenkstotalendoprothese nach Blauth wird seit 1972 ohne Modelländerung eingebaut. In der Kieler Orthopädischen Universitätsklinik überblicken wir bis zum Februar 1981 120 implantierte Knieprothesen. Es wird über die ersten 78 Patienten berichtet, die durchschnittlich 36,7 Monate postoperativ (6-86 Monate) nachuntersucht wurden. Die Beweglichkeit p.o. betrug im Durchschnitt Flexion/Extension 102/2/0 Grad. Aseptische Lockerungen, Materialermüüungsbrüche oder ein meßbares Einsinken der Prothese in den Schienbeinkopf wurden nicht beobachtet. Unter den 21 ersten implantierten Prothesen traten 3 tiefe Infektionen auf, die durch 2 Arthrodesen und eine Oberschenkelamputation behandelt werden mußten. Seitdem wurden schwerwiegende Komplikationen nicht festgestellt. Immer wurde eine volle Achskorrektur und weitgehende Beschwerdefreiheit erreicht.
    Notes: Summary Since 1972 the Blauth knee prosthesis has been used without any changes in design. Up to February 1981 there have been 120 implantations in the department of Orthopedic Surgery of Kiel University. The first 78 cases have been controlled with an average follow-up of 36.7 months. After surgery the mean range of motion was flexion/extension 102/2/0 degrees. Loosening, material insufficiency or measurable sinking of the prosthesis into the tibial plateau were not observed. In only the first 21 implanted knee prostheses were there three infections, two of which had to be treated by arthrodesis and one by amputation. Since then no serious complications have been found. Pain-free movement and correction of leg axis were always achieved.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01287026
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  • 3
    Electronic Resource
    Electronic Resource
    Beitrag zur Chemie der Phosphor-Stickstoff-Verbindungen. Reaktion von Cl2(O)P—NH—P(O)Cl2 mit Tetrahydrofuran (1983)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 501 (1983), S. 191-198 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contribution to the Chemistry of Phosphorus-Nitrogen Compounds. Reaction of Cl2(O)P—NH—P(O)Cl2 with TetrahydrofuranAs well as many phosphorus compounds, the imidodiphosphoryl tetrachloride HN(P(O)Cl2)2 reacts with a large excess of tetrahydrofuran to give the polytetrahydrofuran. Otherwise, if we use smaller molecular ratios THF/HN(P(O)Cl2)2 (1/2 to 3) a polytetrahydrofuran with short chains and N(ω-hydroxypolytetramethylenoxy)imidodiphosphoryl tetrachloride R—N(P(O)Cl2)2; R = H(O(CH2)4)n- are obtained at 22° or 30°C.The 1H and 31P n.m.r. spectra show that oxonium ions are formed with progressive additions of THF to HN(POCl2)2/CCl4 solution. Then two mechanisms have been considered by nucleophilic attack on carbon α of oxonium ion coming from: the free electronic dublett on oxygen of THF to give polytetrahydrofuran or (and) from the nitrogen of imido diphosphoryl tetra chloride anion ((Cl2OP)2N)- to obtain N(ω-hydroxypolytetramethylenoxy)imidodiphosphoryl tetrachloride.
    Notes: Wie im Falle vieler Phosphorverbindungen führt die Reaktion des Imidodiphosphoryltetrachlorids mit einem großen Überschuß Tetrahydrofuran zur Polymerisation des letzteren. Arbeitet man hingegen mit kleinen THF/HN(P(O)Cl2)2 Molverhältnissen (1/2 bis 3), so entsteht bei 22°C bzw. 30°C neben kurzen Poly-THF-Ketten N(ω-hydroxypolytetramethylenoxy)imidodiphosphoryltetrachlorid R—N(P(O)Cl2)2; R = H(O(CH2)4)n-. 1H- und 31P-NMR-Spektren bei stufenweiser Zugabe von THF zu einer HN(P(O)Cl2)2/CCl4-Lösung zeigen, daß sich ein Oxonium-Komplex bildet, der einen nukleophilen Angriff auf das in α-Stellung zum Sauerstoff stehende Kohlenstoffatom durch das Sauerstoffatom des THF oder durch das Stickstoffatom des (N(P(O)Cl2)2)--Anions bewirkt.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19835010623
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  • 4
    Electronic Resource
    Electronic Resource
    Beitrag zur Chemie der Phosphor-Stickstoff-Verbindungen Reaktion von Cl3P=N—P(O)Cl2 mit Tetrahydrofuran (1982)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 489 (1982), S. 204-210 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contribution to the Chemistry of Phosphorus Nitrogen Compounds. Reaction of Cl3P=N—P(O)Cl2 with TetrahydrofuranAs well as many phosphorus compounds, the trichlorophosphazene phosphoryldichloride Cl3P=N—P(O)Cl2 reacts at 30°C with a large excess of tetrahydrofuran to give the polytetrahydrofuran. Otherwise, if we use higher molecular ratios Cl3P=N—P(O)Cl2/THF (respectively 1/3 and 1) we obtain at 30°C beside polytetrahydrofuran the N chlorobutylimidodiphosphoryltetrachloride. This last compound is the main one obtained at 60°C and is probably formed by rearrangement of the O chlorobutyl isomer.However the formation of small quantities of polytetrahydrofuran chains linked with phosphorus cannot be avoided.
    Notes: Läßt man Trichlorophosphazenphosphoryldichlorid Cl3P=N—P(O)Cl2 bei 30°C mit Tetrahydrofuran in großem Überschuß reagieren, so beobachtet man, wie im Falle vieler Phosphorverbindungen, die Polymerisation des Tetrahydrofurans. Arbeitet man hingegen mit höheren Cl3P=N—P(O)Cl2/THF Molverhältnissen 1/3 bis 1, so bildet sich bei 30°C neben Polytetrahydrofuran N-Chlorobutylimidodiphosphoryltetrachlorid. Bei 60°C ist letzteres im Reaktionsgemisch überwiegend. Es bildet sich vermutlich durch Umlagerung des O-Chlorobutyl-Isomeren. Das Entstehen der am Phosphor gebundenen Polytetrahydrofuranketten kann jedoch nicht ganz vermieden werden.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19824890124
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