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  • Aerodynamics
  • GENERAL
  • Inorganic Chemistry
  • 1995-1999  (105)
  • 1955-1959  (65)
  • 1945-1949  (19)
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Year
  • 1
    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
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  • 2
    ISSN: 0009-2940
    Keywords: Alkoxopalladium(II) ; Conformational analysis ; Hydrogen bonding ; Two-dimensional and cage structures ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of palladium acetate with two equivalents of di- and triethanolamines RN(CH2CH2OH)2 in the presence of a base affords the new chelate-stabilized alkoxo Pd(II) complexes [Pd(OCH2CH2N(R)CH2CH2OH)2] [R = Me (1), Et (2), n-Bu (3), benzyl (4) or CH2CH2OH (5)]. These N,O-ligated complexes are isolated in high yield as yellow, crystalline solids and are thermally stable despite the presence of several β-hydrogen atoms in the ligand system. Both complexes possess a square-planar palladium coordination geometry with the two oxygen atoms positioned mutually trans. The most notable difference in the molecular structures is that 1 forms a two dimensional network of intermolecular O-H≡O hydrogen bonds, whereas 5 forms intramolecular O-H⃛O hydrogen bonds, which cage the palladium center. In solution 1-4 exist as a diastereoisomeric mixture (a racemic enantiomeric pair SNSN, RNRN and a mesomeric form RNSN) in a 1:1 molar ratio, and this ratio is independent of temperature in nonalcoholic solvents, When complexes 1-4 are dissolved in protic solvents (e.g. MeOH) the diastereomeric excess is temperature-dependent due to an exchange process between the meso diastereoisomer and the (racemic) enantiomeric pair. Thermodynamic parameters for this process in a mixture of MeOH-toluene have been determined with NMR and show this process to be influenced by the steric nature of the alkyl substituent (R) on nitrogen. A conformational analysis based on 1H-NMR coupling constants within the N,O-chelate ring of complexes 1-4 provides details on the solution structure of the ring in both diastereoisomers.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0044-2313
    Keywords: Perfluorovinyl amine ; X-ray crystal structure ; nucleophile ; electrophile ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reaktion von Perfluorvinyl-Morpholin und Perfluorvinyl-Pyrrolidin mit Nukleophilen und ElektrophilenEs wird die Umsetzung von monofunktionellen und bifunktionellen Nukleophilen sowie des Elektrophils FNO mit Perfluorvinylaminen mitgeteilt. Die Perfluorvinylamine CF=CF2 und CF=CF2 wurden mit Dimethylamin und Diethylamin in Gegenwart kleiner Mengen Wasser umgesetzt zu CHFC(O)N(CH3)2 (1), CHFC(O)N(CH3)2 (2), bzw. CHFC(O)N(C2H5)2 (3). Mit Perfluorvinylpyrrolidin und Perfluorvinylmorpholin ergibt Ethanolamin die cyclischen Produkte CHF (4) bzw. CHF (5). Die Reaktion der Vinylamine mit (CH3)3SiOCH2CF3 in Gegenwart katalytischer Mengen von CsF ergibt cis- (6) und trans- (7) CF=CF(OCH2CF3) sowie cis- (8) und trans-(9) CF=CF(OCH2=CF3). Das elektrophile FNO reagiert langsam mit Perfluorvinylpyrrolidin und Perfluorvinylmorpholin und schneller mit (CH3)3CCF=CF2 zu CF(NO)CF3 (10), CF(NO)CF3 (11) bzw. (CF3)CF(NO)CF3 (12). Die Einkristall-Röntgen-Analyse wird zur Klärung der Produkte der kontrollierten Hydrolyse der Sultone von Perfluorvinylpyrrolidin wie des Sulfonsäureanhydrids C(O)CF2OS(O)2OCF2C(O) (13) eingesetzt. Die Röntgenstruktur von Perfluorbernsteinsäure · Monohydrat (14), die durch Hydrolyse von Perfluorvinylpyrrolidin mit einem Überschuß an Wasser erhalten wurde, wird erstmals mitgeteilt.
    Notes: In this study, both monofunctional and bifunctional nucleophiles, as well as the electrophile FNO, are reacted with perfluorovinyl amines. The perfluorovinyl amines CF=CF2 and CF=CF2 have been reacted with dimethylamine and diethylamine in the presence of small amounts of water to give CHFC(O)N(CH3)2 (1), CHFC(O)N(CH3)2 (2), and CHFC(O)N(C2H5)2 (3). With perfluorovinyl pyrrolidine and perfluorovinyl morpholine, ethanolamine gives the cyclized products CHF (4) and CHF (5), respectively. Reaction of the vinyl amines with (CH3)3SiOCH2CF3 in the presence of catalytic amounts of CsF results in the formation of cis- (6) and trans- (7) CF=CF(OCH2CF3) and cis- (8) and trans- (9) CF=CF(OCH2CF3). The electrophile FNO reacts slowly with perfluorovinyl pyrrolidine and perfluorovinyl morpholine, and more rapidly with (CF3)3CCF=CF2 to give CF(NO)CF3 (10), CF(NO)CF3 (11) and (CF3)3CF(NO)CF3 (12), respectively. Single crystal X-ray analysis is used to confirm the identity of the product obtained from the controlled hydrolysis of the sultone of perfluorovinyl pyrrolidine as the sulfonic acid anhydride C(O)CF2OS(O)2OCF2C(O) (13). The X-ray crystal structure of perfluorosuccinic acid monohydrate (14), which is obtained when the perfluorovinyl pyrrolidine sultone is hydrolyzed in excess water, is also reported for the first time.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Publication Date: 2011-08-16
    Keywords: GENERAL
    Type: NACA Conf. on Aerodyn. of High Speed Aircraft; p 93-103
    Format: text
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  • 5
    Publication Date: 2019-06-28
    Description: The thrust efficiency and vectoring performance of a convergent-divergent nozzle were investigated at static conditions in the model preparation area of the Langley 16-Foot Transonic Tunnel. The diamond-shaped nozzle was capable of varying the internal contour of each quadrant individually by using cam mechanisms and retractable drawers to produce pitch and yaw thrust vectoring. Pitch thrust vectoring was achieved by either retracting the lower drawers to incline the throat or varying the internal flow-path contours to incline the throat. Yaw thrust vectoring was achieved by reducing flow area left of the nozzle centerline and increasing flow area right of the nozzle centerline; a skewed throat deflected the flow in the lateral direction.
    Keywords: Aerodynamics
    Type: NASA-TP-3628 , NAS 1.60:3628 , L-17570
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  • 6
    Publication Date: 2019-07-12
    Description: During an investigation of the J57-P-1 turbojet engine in the Lewis altitude wind tunnel, effects of inlet-flow distortion on engine stall characteristics and operating limits were determined. In addition to a uniform inlet-flow profile, the inlet-pressure distortions imposed included two radial, two circumferential, and one combined radial-circumferential profile. Data were obtained over a range of compressor speeds at an altitude of 50,000 and a flight Mach number of 0.8; in addition, the high- and low-speed engine operating limits were investigated up to the maximum operable altitude. The effect of changing the compressor bleed position on the stall and operating limits was determined for one of the inlet distortions. The circumferential distortions lowered the compressor stall pressure ratios; this resulted in less fuel-flow margin between steady-state operation and compressor stall. Consequently, the altitude operating Limits with circumferential distortions were reduced compared with the uniform inlet profile. Radial inlet-pressure distortions increased the pressure ratio required for compressor stall over that obtained with uniform inlet flow; this resulted in higher altitude operating limits. Likewise, the stall-limit fuel flows required with the radial inlet-pressure distortions were considerably higher than those obtained with the uniform inlet-pressure profile. A combined radial-circumferential inlet distortion had effects on the engine similar to the circumferential distortion. Bleeding air between the two compressors eliminated the low-speed stall limit and thus permitted higher altitude operation than was possible without compressor bleed.
    Keywords: Aerodynamics
    Type: NACA-RM-SE55E23
    Format: application/pdf
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  • 7
    Publication Date: 2019-07-13
    Description: The history of the Computational Fluids Laboratory -3D (CFL3D) Navier-Stokes computer code is discussed and a comprehensive reference list is given. Three recent advanced applications are presented (1) Wing with partial-spanflap, (2) F/A-18 with forebody control strake, and (3) Noise predictions for an advanced ducted propeller turbomachinery flow.
    Keywords: Aerodynamics
    Type: NASA-TM-112861 , NAS 1.15:112861 , Gudunov''s Method for Gas Dynamics: Current Applications and Future Developments; May 01, 1997 - May 02, 1997; Ann Arbor, MI; United States
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  • 8
    Publication Date: 2019-07-10
    Description: This document is the User's Manual for the CFL3D computer code, a thin-layer Reynolds-averaged Navier-Stokes flow solver for structured multiple-zone grids. Descriptions of the code's input parameters, non-dimensionalizations, file formats, boundary conditions, and equations are included. Sample 2-D and 3-D test cases are also described, and many helpful hints for using the code are provided.
    Keywords: Aerodynamics
    Type: NASA/TM-1998-208444 , NAS 1.15:208444 , L-17702
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 129 (1996), S. 283-287 
    ISSN: 0009-2940
    Keywords: Self-assembling frameworks ; Thermal stability ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Here we report on investigations that have revealed for the first time that the Cs+ ion templates the same metal germanium sulfide open-framework as (CH3)4N+ (TMA+), and that metal complexing agents enhance crystal size by at least two orders of magnitude. The synthesis, structures and thermal properties of Cs2FeGe4S10 ·× H2O and TMA2FeGe4S10 are also described. Both have 3D zinc blende-type open-framework structures. These materials have the same connectivity as TMA2MnGe4S10. The tetrahedral sites in the lattice are alternately substituted by pseudo-tetrahedral Fe2+ and adamantanoid Ge4S104- building blocks, covalently linked together by Fe(μ-S)Ge bridge bonds, to give a tetragonal unit cell. The charge-balance of the anionic framework [Fe-Ge4S10]2- is maintained by either Cs+ or TMA+ ions in the cavity spaces. Synthesis of these materials demonstrates an interesting example of a self-assembly process in which a 3D framework is built from molecular precursors. Water adsorption-desorption cycling from room temperature to 200 °C reveals framework flexibility between larger and smaller tetragonal unit cell 14 isotypes. The compound TMA2FeGe4S10 is stable in nitrogen at 350 °C and under vacuum at 450 °C. The corresponding temperatures for Cs2FeGe4S10 are 530 °C and 630°C; it is stable on cooling to room temperature under vacuum, and after subsequent exposure to air. Six hundred thirty degrees celsius is the highest recorded temperature at which the integrity of a non-oxide framework has been maintained. The framework stability and flexibility of “all-inorganic” Cs2FeGe4S10 provides an encouraging example for researchers interested in developing sulfide-based framework materials with practical applications.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 0009-2940
    Keywords: Phosphaalkenes, C-halo, C-metal ; Phosphaacrylic acid ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Thermally and air-stable β-phosphaenones were synthesized by functionalization of Mes*P=CCl2 (1; Mes* = supermesityl = 2,4,6-tri-tert-butylphenyl). At low temperature, 1 was lithiated by halogen-metal exchange with n-butyllithium to give the phosphanylidene carbenoid (Z)-Mes*P=C(Cl)Li [(Z)-2] which reacted with acid chlorides to furnish the C-carbonyl-substituted phosphaalkenes (Z)-Mes*P=C(Cl)R (3: P = COtBu; 4: R = COPh; 5: R = COOEt). The reaction of (Z)-2 with carbon dioxide furnished the carboxylate 6, which was converted by treatment with pivaloyl chloride or trimethylsilyl chloride into the phosphaalkenes 7 and 8 functionalized at the carbon atom by an anhydride or a trimethylsilyl ester function, respectively. Acidification of 6 or hydrolysis of 8 with water in chloroform solution afforded the novel carboxylic acid (Z)-Mes*P=C(Cl)COOH (9). Spectroscopic investigations (NMR, UV, IR) of 3-9 and the X-ray structures of 3 and 4 are presented. Based on these properties and on theoretical calculations, the occurrence of conjugation in the β-phosphaenone system is discussed and compared with the well-known conjugation in normal enones.
    Additional Material: 2 Ill.
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