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  • Inorganic Chemistry  (8,572)
  • Aerodynamics
  • 2005-2009  (338)
  • 1995-1999  (2,366)
  • 1975-1979  (3,768)
  • 1920-1924
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  • 1
    Electronic Resource
    Electronic Resource
    A methodology for assessing manufacturing cost due to tolerance of aerodynamic surface features on turbofan nacelles (1998)
    Springer
    The international journal of advanced manufacturing technology 14 (1998), S. 894-900 
    Details
    ISSN: 1433-3015
    Keywords: Aerodynamics ; Concurrent engineering ; Manufacturing costs ; Optimisation ; Statistical models ; Tolerances
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract A component of the direct operating cost of aircraft is that associated with the manufacturing cost. This affects depreciation, interest, insurance and maintenance charges. By relaxing the requirements for aerodynamic surface smoothness the manufacturing cost can be reduced at the expense of an increase in drag and corresponding fuel costs. This work is part of a study to examine this multidisciplinary problem. Only isolated turbofan nacelles are considered. The costs associated with assigning different tolerance levels to the feature dimensions on nacelles are assessed. A statistical procedure is employed to estimate the cost-tolerance relationship for eleven features involving gaps, steps, surface profile and fastener flushness. This procedure requires actual manufacturing and cost source data. A knowledge of the cost-tolerance relationships is useful in a concurrent engineering context. It will allow aerodynamicists to optimise surface smoothness in consultation with production engineers, thus achieving the best compromise between cost and drag.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01179079
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  • 2
    Electronic Resource
    Electronic Resource
    Edge Singularities and Kutta Condition in 3D Aerodynamics (1999)
    Springer
    Meccanica 34 (1999), S. 199-229 
    Details
    ISSN: 1572-9648
    Keywords: Aerodynamics ; Kutta condition ; Edge singularities ; Boundary integral equations ; Fluid dynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract This review paper presents a unified formulation of the Kutta condition for steady and unsteady flows, implemented by removing all unbounded velocity singularities (of power‐law and logarithmic type) at the trailing edge, and including nonlinear wakes and thick swept‐back wings. A suitable boundary integral approach is adopted and the uniqueness issue is discussed for several wing configurations of interest in aerodynamics. Sommario. Si presenta una formulazione unificata della condizione di Kutta per flussi stazionari e non stazionari, ottenuta imponendo la limitatezza della velocità al bordo d'uscita, e valida nel caso nonlineare anche per ali a freccia. Si utilizza un opportuno approccio integrale al contorno e si discute il problema dell'unicità per svariate configurazioni alari di interesse nelle applicazioni.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004571915758
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  • 3
    Electronic Resource
    Electronic Resource
    Masthead (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975) 
    Details
    ISSN: 0009-2940
    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/cber.19751080101
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  • 4
    Electronic Resource
    Electronic Resource
    Zur Kenntnis des Narciclasins (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 445-463 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chemistry of NariciclasineFrom narciclasine (2a), the acetonide 8a and its oxidation product 10 are prepared. 10 isomerizes easily to give 11. Catalytic hydrogenation of 2a yields a mixture of dihydronarci-clasines from which the pure cis- and trans-isomers 14a and 15a can be obtained via the tetraacetates. As a by-product of the hydrogenation, isonarciclasine (16a) is isolated. The relative configuration of narciclasine (as represented by formula 2a) is established by the n. m. r. spectra of 15b and 16b. Lycoricidine and margetine are shown to be identical; their configuration is as shown in formula 2b. Some biological tests are reported.
    Notes: Aus Narciclasin (2a) wird das Acetonid 8a und dessen Oxidationsprodukt 10 dargestellt. 10 wird leicht zu 11 isomerisiert. Das bei der katalytischen Hydrierung von 2a anfallende Gemisch der Dihydronarciclasine wird über die Tetraacetate in die cis- und trans-Verbindungen 14a und 15a aufgetrennt. Als Nebenprodukt der katalytischen Hydrierung entsteht Isonarciclasin (16a). Mit Hilfe der NMR-Spektren von 15b und 16b läßt sich die relative Konfiguration des Narciclasins entsprechend 2a beweisen. Lycoricidin und Margetin sind identisch und haben die Konfiguration 2b. Über einige biologische Teste wird berichtet.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080210
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  • 5
    Electronic Resource
    Electronic Resource
    Komplexchemie reaktiver organischer Verbindungen, V. Reaktionen aliphatischer Diazoverbindungen mit thermolabilen Mangan-Komplexen (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 486-499 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Complex Chemistry of Reactive Organic Compounds, V. Reaction of Aliphatic Diazo Compound with Thermolabile Manganese ComplexesAliphatic diazo compounds react with the manganese- tetrahydrofurane complexes 1 and 2, respectively, to yield olefine, ketimine or carbene complexes: 3-diazo-2- butanone (3b) reacts with 2 under intramolecular hydride transfer to give the buten-2- one complex 7, while 3-diazocamphor (3c) leads to the 3-iminocamphor complex 8. Benzolyphenyldiazomethane (3a), diphenyldiazomethane (9a), and its p-substituted derivatives 9b-f are shown to be preliminary stages for the stable carbene complexes 4, 10, and 11, the spectra of which are discussed. The diphenylcarbene ligand can be split off by triphenylphosphine, carbon monoxide, ammonium cerium(IV) nitrate, and by thermolysis.
    Notes: Aliphatische Diazoverbindungen reagieren mit den Mangan-THF- Komplexen 1 bzw. 2 zu Olefin-, Ketimin- oder Carben-Komplexen: Während 3-Diazo-2-butanon (3b) mit 2 unter intramolekularer Hydridverschiebung den Buten-2- on-Komplex 7 ergibt, bildet 3-Diazo-campher (3c) bei Umsetzung mit 2 den 3-Iminocampher-Komplex 8. Benzoylphenyldiazomethan (3a) sowie Diphenyldiazomethan (9a) und seine p- substituierten Derivate 9b-f verhalten sich gegenüber 1 und 2 als Vorstufen für die stabilen Carben-Komplexe 4, 10 und 11, deren Spektren diskutiert werden. Der Diphenylcarben-Ligand in 11a kann mit Triphenylphosphin, Kohlenmonoxid und Ammoniumcer(IV)-nitrat sowie durch Thermolyse abgespalten werden.
    Additional Material: 7 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080213
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  • 6
    Electronic Resource
    Electronic Resource
    Photochemische Dimerisierung von 1,4- Dialkinylbenzolen (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 528-537 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photochemical Dimerisation dof 1,4-DialkynylbenzenesOn irradiation with ultraviolet light 1,4-diethynylbenzene (4a) forms blue unstable 6-ethynyl-1-(4- ethynylphenyl)azulene (5) and 6-ethynyl-2-(4-ethynylphenyl)azulene (6) besides polymers. The photolysis of 1,4-bis(phenylethynyl)benzene (4b) yields stable green 2,3-diphenyl-6-phenylethynyl-1-[4- (phenylethynyl)phenyl]azulene (9) and the isomeric naphthalene 11. Products of catalytic reduction of 5, 9, and 11 are described.
    Notes: Aus 1,4-Diäthinylbenzol (4a) entstehen bei Bestrahlung mit ultraviolettem Licht das wenig beständige, blaue 6-Äthinyl-1-(4-äthinylphenyl)azulen (5) und 6-Äthinyl-2-(4-äthinylphenyl)-azulen (6) neben polymeren Produkten. Dagegen führt die Photolyse von 1,4-Bis(phenyl-äthinyl)benzol (4b) zu dem beständigen grünen 2,3-Diphenyl-6-phenyläthinyl-1-[4-(phenyl-äthinyl)phenyl]azulen (9) und dem isomeren Naphthalin-Derivat 11. Reduktionsprodukte von 5, 9 und 11 werden beschrieben.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080218
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  • 7
    Electronic Resource
    Electronic Resource
    Derivate des Methylendioxybenzols, 40. Synthese des Ferrugons und des Pseudoferrugons (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 561-568 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Derivatives of Methylendioxybenzene, 40. the Synthesis of Ferrugone and PseudoferrugoneThe isoflavones ferrugone (1a) and pseudoferrugone (1a) as well as their dihydro derivatives 2a and b are prepared from the apione derivatives 5f of 6f and the chromene or chroman derivatives 4d and 3p.
    Notes: Die Isoflavone Ferrugon (1a) und Pseudoferrugon (1b) sowie die Dihydroverbindungen 2a und b werden durch Reaktion der Apionderivate5f und 6f mit den Chromen- bzw. Chroman-derivaten 4d bzw. 36p dargestellt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080221
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  • 8
    Electronic Resource
    Electronic Resource
    Methylendioxyhetarene, 1. Zur Darstellung von 3,4- Methylendioxythiophen-, -furan- und pyrrol- abkömmlingen (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 569-575 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Methylenedioxyhetarenes, 1. On the Preparation of 3, 4- Methylenedioxythiophene-, furan- and -pyrrole DerivativesMethylenation experiments with 3, 4-dihydroxy compounds of diethyl thiophene-, furan-, 1-phenyl-, and 1- (ethoxycarbonylmethyl)-2, 5-pyrroledicarboxylate are reported. Methylenations lead only with diethyl 3, 4-dihydroxy-2, 5- thiophenedicarboxylate (1) to the 3, 4- methylenedioxythiophene derivatives 2 and 3 with formation of diethyl dithieno[3, 4-b: 3′, 4′- g]tetroxecin-1, 3, 7, 9-tetracarboxylate (4) as by- product. The furan- (5a) and pyrrole derivatives 7a and b give the tetraethyl difuro- (6) and dipyrrolo[3, 4-b: 3′, 4′-g]tetroxecin- 1, 3, 7, 9-tetracarboxylates 8a and b, respectively.
    Notes: Es wird über Methylenierungsversuche an 3,4-Dihydroxy- Verbindungen der Thiophen-Furan-, 1-Phenyl- und 1- (Äthoxycarbonylmethyl)-2,5-pyrroldicarbonsäure- diäthylester berichtet. Die Methylenierungen führen nur beim 3,4-Dihydroxy-2,5-thiophendicarbonsäure-diäthylester (1) zu den 3,4-Methylendioxythiophen-Derivaten 2 und 3, wobei als Nebenprodukt der Dithieno[3,4-b: 3′,4′-g]tetroxecin-1,3,7,0-tetracarbonsäure- tetraäthylester (4) gebildet wird. Bei dem Furan- (5a) und den Pyrrol-Derivaten 7a und b entstehen die Difuro- (6) bzw. die Dipyrrolo[3,4- b: 3′,4′-g]tetroxecin-1,3,7,9- tetracarbonsäure-tetraäthylester 8a, b.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080222
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  • 9
    Electronic Resource
    Electronic Resource
    Reaktionen von N, N-Dialkyl- und N, N-Diarylsulfamiden mit Chlorsulfonylisocyanat (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 618-622 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reaction of N, N-Dialkyl- and N, N-Diarylsullfamides with Chlorosulfonyl IsocyanateChlorosulfonyl isocyanate reacts with N, N-dialkyl- or N, N-diarylsulfamides to give the so far unknown N-chlorosulfonyl-N′-(dialkyl- and -diarylsulfamoyl)ureas (3a-e), which may be hydrolysed to the corresponding N-(dialkyl- and -diarylsulfamoyl)ureas (4a-e). The pyrolysis of 3a-e leads to the formation of the known sulfamoyl chlorides.
    Notes: Durch Umsetzung von Chlorsulfonylisocyanat mit N, N-Dialkyl- oder N, N-Diarylsulfamiden erhält man die bisher unbekannten N-Chlorsulfonyl-N′-(dialkyl- und -diarylsulfamoyl)harnstoffe (3a-e), die sich zu N-(Dialkyl- und-Diarylsulfamoyl)harnstoffen (4a-e) hydrolysieren lassen. Die Pyrolyse von 3a-e liefert die bekannten Sulfamidsäurechloride.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080227
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  • 10
    Electronic Resource
    Electronic Resource
    Zur Photochemie des Allens (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 657-663 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Photochemistry of AlleneAcetophenone-sensitized irradiation of allene yields a complex mixture of products, from which the allene dimer 1, the trimers 2 and 3, and the ketones 4 and 5 have been isolated. This is in contrast to the reported thermal di- and trimerization of allene, which lead to products such as 1, 8-12. The planar allene triplet 13, derived by way of a nonvertical triplet-triplet energy transfer, presumably plays a key role in the photosensitized oligomerization of allene. Also, the formation of the ketone 5 is easily explained in terms of an attack of 13, through its central C-atom to the o-position of the acetophenone, to give 16, which cyclizes ultimately to yield 5. At 240°C, 5 undergoes fragmentation to the starting materials. The α,β-unsaturated ketone 4 arises through a [2 + 2]-photocycloaddition reaction of the 3(n,π*) state of acetophenone to methylacetylene via the oxetene intermediate 6, followed by ring-opening.
    Notes: Die acetophenon-sensibilisierte Belichtung von Allen liefert eine komplexe Produktmischung, aus der sich das Allendimere 1, die Trimeren 2 und 3 sowie die Ketone 4 und 5 isolieren lassen. Dieser Befund steht im Gegensatz zur beschriebenen thermischen Di- und Trimerisierung des Allens, die zu 1, 8-12 führt. Eine Schlüsselrolle bei der photosensibilisierten Allen-Oligomerisierung spielt vermutlich das durch nichtvertikale Triplett-Triplett-Energieübertragung gebildete planare Allen-Triplett 13. Auch die Entstehung des Bicyclo[4.2.0]octadien-Ketons 5 erklärt sich zwanglos durch einen Angriff von 13 mit seinem mittleren C-Atom in der o-Position des Acetophenons unter Bildung der Zwischenstufe 16, die Ringschluß zu 5 erfährt. Bei 240°C erleidet 5 Rückspaltung in die Ausgangskomponenten. Das α,β-ungesättigte Keton 4 ist dagegen Ergebnis einer [2 + 2]-Photocycloaddition des Acetophenons im 3(n,π*)-Zustand an Methylacetylen zum Oxeten 6 mit anschließender Ringöffnung.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080231
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