ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
  • Chemical Engineering  (325)
  • Fisheries
  • GENERAL
  • Inorganic Chemistry
  • Organic Chemistry
  • 1975-1979  (441)
  • 1955-1959  (189)
  • 1
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Eine thermische (a) und eine reduktive (b) Methode zur Herstellung von Mikanez-Estern wird beschrieben. Bei der ersten gelang der Nachweis des monomeren Vorläufers, 1,3-Butadien-2-carboxylester. (a)trans/cis-Gemische von Methyl resp. Äthyl 2-Brom-1-methylcyclopropancarboxylat (14/15 resp. 16/17), mit Tri-n-butylzinnhydrid aus den entsprechenden 2,2-Dibrom-1-methylcyclopropancarboxylaten 12 resp. 13 hergestellt, wurden bei 480°/1,7 Torr pyrolysiert. Die bei -78° daraus abgefangenen Kondensate bestanden aus den 1,3-Butadien-2-carboxylaten 5 und 6, im Falle des Äthylesters 6 durch seine 1H-NMR.-Signale charakterisiert und als Addukt (19) mit 4-Phenyl-1,2,4-triazolin-3,5-dion (18) abgefangen (55%). Beim Erwärmen der Kondensate dimerisierten die Dienester 5 resp. 6, so dass sich Dimethyl resp. Diäthyl Mikanezat (9 resp. 10) isolieren liess (67 resp. 100%).(b)Behandlung von Methyl 2(E)-2-Methyl-2-butenoat (20) mit 2 Äquivalenten N-Bromsuccinimid gab (25%) Methyl 2(Z)-4-Brom-2-brommethyl-2-butenoat (21). (Mit 3 Äquivalenten entstand ein Stereomerengemisch 2(Z)- und 2(E)-4,4-Dibrom-2-brommethyl-2-butenoat (22 und 23)). Reduktion des Dibromesters 21 mit Zink in Tetrahydrofuran, Methanol oder Eisessig ergab (50%) Dimethyl Mikanezat (9). Von einer Iodolaktonisierung der aus 9 durch Verseifung hergestellten Mikanezsäure (8) erhielt man 4-Iodo-7-oxo-1-vinyl-6-oxabicyclo[3.2.1]octan-4endo-carbonsäure (24), dessen Bildungsleichtigkeit und IR.-Bande bei 1780 cm eine unabhängige Bestätigung dafür liefert, dass Mikanezsäure (8) durch Kopf-zu-Kopf-Diels-Alder-Dimerisierung von 1,3-Butadien-2-carbonsäure (4) entsteht.Aus Methyl (E)-2-Methyl-2-pentenoat (25) wurde auf gleiche Weise, d.h. über Dibromierung zu 27 und Reduktion mit Zink in Äther, Dimethyl 3,2′-Dimethylmikanezat (29) gewonnen. Die Multiplizität des 1H-NMR.-Signals von H—C(3) in 29 bestätigt, wiederum unabhängig, dass die Dimerisierung des Dienesters (in diesem Fall 28) in Kopf-zu-Kopf-Diels-Alder-Weise stattfindet.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 92 (1959), S. 2694-2700 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Die von E. Fischer und G. Bertrand beschriebenen Tribenzal-L-idite erwiesen sich als identisch mit 1.3;2.4;5.6-Tribenzal-L-idit. Unter wenig abgeänderten Versuchsbedingungen entsteht neben dem Tribenzal-L-idit ein Dibenzal-Derivat, welches einen 2.3.4.5-, wahrscheinlich 2.4;3.5-Dibenzal-L-idit darstellt. Es wird auf den unterschiedlichen Verlauf der Acetalisierung des L-Idits mit Benzaldehyd, bzw. Formaldehyd hingewiesen.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 22 (1976), S. 289-297 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A flash photomicrographic method and modified dye-light transmittance technique are employed to measure size distributions and mixing frequencies in a turbulently agitated flow vessel. This liquid-liquid dispersion is nearly spatially homogenous. Mixing frequencies are strongly dependent on impeller speed and moderately dependent on holdup fraction.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 22 (1976), S. 744-750 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Random search procedures have recently been successfully applied to the optimization of a variety of chemical engineering problems, including optimization of chemical processes by flow sheet simulation. These procedures represent the independent variables as random variables described by probability distributions. The adaptive random search procedure centers the distribution for each variable about the best search point found and examines this region for a better point. Thus, this technique has the ability of continuously moving the search region toward the optimum, which is particularly advantageous in following constraints.This study examines the efficiency of the adaptive random search technique as applied to six different problems, which have been previously solved by various other techniques.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 22 (1976), S. 851-855 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Bench scale packed columns were used to study the kinetic behavior of biological denitrification. After tracer studies were run to determine flow characteristics, steady state nitrate profiles were determined. A first-order rate expression with an Arrhenius temperature dependence is an adequate model of the reaction for nitrate-nitrogen concentrations of 〈 100 mg/l and temperature of 5° to 20°C. The rate constants are proportional to the packing surface area.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 33-36 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Experimental equilibrium vapor and liquid compositions are reported for the hydrogen-methane system at -150°, -200°, and -250°F. and at pressures of 500 to 4,000 lb./sq. in. The ternary system hydrogen-methane-propane was studied at 0°, -100°, and -200°F. at 500 and 1,000 lb./sq. in. Phase compositions were determined for a limited number of similar conditions for the hydrogen-methane-propylene and hydrogen-methane-ethylene-ethane-propylene-propane systems.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 4 (1958), S. 439-444 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: That phase equilibrium exists at the gas-liquid interface during gas absorption is usually assumed in the analysis and design of absorption equipment, but the validity of this assumption has been in doubt since Higbie's pioneering gas-absorption studies. Accurate measurements are reported herein of the absorption rates at 25°C. of carbon dioxide into short water jets in which the liquid was in laminar flow. The jets issued from circular nozzles of about 1.5-mm. diam., flowed intact downward through an atmosphere of carbon dioxide at average velocities of from 75 to 550 cm./sec. over distances of 1 to 15 cm., and were collected in a receiver slightly larger in diameter than the nozzles. The measured absorption rates are in excellent agreement with predictions based on unsteady state diffusion theory, when one assumes interfacial equilibrium. It is concluded from these results and those of other investigators that equilibrium prevails at a freshly formed, relatively clean, carbon dioxide-water interface and that the same statement probably applies to the absorption of other slightly soluble gases in water.Evidence is discussed which indicates that an accumulation of minute quantitities of surface-active materials may seriously reduce the rate of gas absorption, either by affecting the hydrodynamic characteristics of the system or perhaps by offering resistance to the transfer of solute molecules across the interface.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The separation of 4.5 g. of americium from approximately a kilogram of light rare earths (primarily lanthanum) was achieved on a pilot plant scale by chromatographic displacement of the mixture from Dowex-50 resin with 0.1% ammonium citrate at pH 8 into hydrogen-form Dowex-50. The americium collected into a narrow band and was eluted free from lanthanum but contained an equal weight of cerium. A 6- and a 2-in.-diam. column were used in tandem. Use of a final column with a much smaller diameter would have permitted a cleaner separation from cerium, but this was left for a laboratory-scale separation by a different process. Precipitation, which was observed in the columns during the first runs, was later avoided entriely by use of high flow rates both initially and during the transfer between columns. No adverse effects were noted from ∼15 curies of alpha activity.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 5 (1959), S. 397-402 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In connection with a study of the mechanism of gas absorption the problem arose of predicting absorption rates into laminar liquid jets. A solution to the problem is presented in this paper, which provides an example of the application of fluid dynamics to the analysis of mass transfer in a complex flow system.The water jets considered here issued from circular nozzles of about 1.5-mm diameter, flowed intact downward through an atmosphere of solute gas at average velocities of from 75 to 550 cm./sec. over distances of 1 to 15 cm., and were collected in a receiver slightly larger in diameter than the nozzles. Equations describing the liquid flow near the jet surface are deduced from measurements of jet diameter and analogy to related flow situations. When one uses these equations, absorption rates are predicted from unsteady state diffusion theory with the assumption of interfacial equilibrium. The predicted rates for carbon dioxide at 25°C are in close agreement with experimental determinations over the observed range of contact time of the liquid with gas, namely 0.003 to 0.04 sec.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 21 (1975), S. 623-623 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...