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  • Engineering  (5)
  • thermal conductivity  (3)
  • Endogenous depression  (2)
  • 1
    Digitale Medien
    Digitale Medien
    Thermal conductivity of R32 and its mixture with R134a (1995)
    Springer
    International journal of thermophysics 16 (1995), S. 1193-1201 
    Details
    ISSN: 1572-9567
    Schlagwort(e): R134a, R32 ; R32+R134a mixture ; thermal conductivity ; transient hot-wire method
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract The liquid thermal conductivity of R32 (CH2F2) and R134a (CF3CH2F) was measured in the range from 223 to 323 K and from 2 to 20 MPa by the transient hot-wire method. The thermal conductivity of the R32+R134a mixture was also measured in the same range by varying the mass fraction of R32. The measured data are analyzed to obtain a correlation in terms of temperature, pressure and composition of the mixture. The uncertainty of our measurements is estimated to be within ±2%.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02081287
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  • 2
    Digitale Medien
    Digitale Medien
    Thermal conductivity of CVD diamond films (1996)
    Springer
    International journal of thermophysics 17 (1996), S. 695-703 
    Details
    ISSN: 1572-9567
    Schlagwort(e): AC calorimetry ; CVD diamond film ; Debye phonon model ; grain boundary ; thermal conductivity ; thermal diffusivity ; U-process
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract Diamond films 60 and 170 µm in thickness were grown by PACVD (plasma-assisted chemical vapor deposition) under similar conditions. The thermal diffusivity of these freestanding films was measured between 100 and 300 K using AC calorimetry. Radiation heat loss from the surface was estimated by analyzing both the amplitude and the phase shift of a lock-in amplifier signal. Thermal conductivity was calculated using the specific heat data of natural diamond. At room temperature, the thermal conductivity of the 60 and 170 υm films is 9 and 16 W-cm−1. K−1 respectively, which is 40–70% that of natural diamond, The temperature dependence of thermal conductivity of the CVD diamond films is similar to that of natural diamond, Phonon scattering processes are considered using the Debye model, The microsize of the grain boundary has a significant effect on the mean free path of phonons at low temperatures. The grain in CVD diamond film is grown as a columnar structure, Thus, the thicker film has the larger mean grain size and the higher thermal conductivity. Scanning electron microscopy (SEM) and Raman spectroscopy were used to study the microstructure of the CVD diamond films. In this experiment, we evaluated the quality of CVD diamond film of the whole sample by measuring the thermal conductivity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01441515
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  • 3
    Digitale Medien
    Digitale Medien
    Measurement of the Thermal Conductivity of Si and GaAs Wafers Using the Photothermal Displacement Technique (1998)
    Springer
    International journal of thermophysics 19 (1998), S. 281-290 
    Details
    ISSN: 1572-9567
    Schlagwort(e): GaAs ; impurities ; phonons ; photothermal displacement technique ; semiconductors ; Si ; thermal conductivity ; thermal diffusivity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract Thermal conductivity and thermal diffusivity of Si and GaAs wafers were measured using the photothermal displacement technique, and the temperature dependence of these two quantities was investigated. Thermal diffusivity was obtained from the phase difference between the heating source and the signal, and thermal conductivity was determined from the maximum value of the signal amplitude in the temperature range 80 to 300 K. It was verified that an increase in doping concentration gives rise to a decrease in thermal conductivity at low temperatures. The experimental results obtained on samples with different types and doping concentrations are consistent with those expected from theoretical considerations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1021467606454
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  • 4
    Digitale Medien
    Digitale Medien
    Increased serum glutamate in depressed patients (1982)
    Springer
    European archives of psychiatry and clinical neuroscience 232 (1982), S. 299-304 
    Details
    ISSN: 1433-8491
    Schlagwort(e): Serum glutamate ; Endogenous depression ; Neurotic depression ; Antidepressants ; Serum-Glutamat ; endogene Depression ; neurotische Depression ; Antidepressiva
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Der Serum-Glutamatgehalt wurde bei endogen depressiven, neurotisch depressiven, schizophrenen und schizoaffektiven Patienten sowie gesunden Kontrollpersonen bestimmt. Hierbei zeigte sich, daß die Serumglutamatspiegel bei endogen und neurotisch Depressiven signifikant höher waren als bei den anderen Gruppen. Zwischen schizophrenen und schizoaffektiven Patienten sowie Kontrollen zeigten sich dagegen keine signifikanten Unterschiede. Die weitere Analyse der Daten erbrachte die Hypothese, daß die erhöhten Serum-Glutamat-Konzentrationen bei endogen und neurotisch Depressiven eine Folge der antidepressiven Medikation sind. Diese Ergebnisse werden im Hinblick auf die Wirkung der Antidepressiva auf das Serum-Glutamat bei affektiven Störungen diskutiert.
    Notizen: Summary Glutamate concentration was determined in serum from endogenous and neurotic depressive patients, in persons with schizophrenia or schizoaffective disorder, and in normal subjects. The mean serum glutamate level in the endogenous and neurotic depressive patients was found to be significantly higher than in any of the other groups. No other statistically significant differences were found. Statistical analysis revealed that the elevated serum glutamate concentration in the endogenous and neurotic depressive patients was probably caused by medication. These results are discussed in view of the effect of antidepressants upon the serum glutamate in the affective disorders.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00345492
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  • 5
    Digitale Medien
    Digitale Medien
    Levels of total and free tryptophan in the plasma of endogenous and neurotic depressives (1981)
    Springer
    European archives of psychiatry and clinical neuroscience 231 (1981), S. 35-39 
    Details
    ISSN: 1433-8491
    Schlagwort(e): Total tryptophan ; Free tryptophan ; Endogenous depression ; Neurotic depression ; Gesamt- und freies Tryptophan ; Endogene Depression ; Neurotische Depression
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Gesamt- und freies Tryptophan wurde im Plasma von 34 endogen Depressiven, 20 neurotisch Depressiven und 25 gesunden Kontrollpersonen bestimmt. Während beim Gesamttryptophan kein Unterschied zwischen den drei Gruppen festgestellt werden konnte, war das freie Tryptophan bei endogen Depressiven und neurotisch Depressiven signifikant erniedrigt. Zwischen endogen und neurotisch Depressiven fand sich kein Unterschied.
    Notizen: Summary The levels of total and free tryptophan were determined in the plasma of 34 endogenous depressives, 20 neurotic depressives and 25 healthy volunteers. Whilst the levels of total tryptophan were not different in the three groups, the level of free tryptophan was reduced in both endogenous and neurotic depressives. No difference could be found between endogenous and neurotic depressives.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00342828
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  • 6
    Digitale Medien
    Digitale Medien
    A simple and efficient mixed harmonic element for shells of revolution (1997)
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 13 (1997), S. 565-572 
    Details
    ISSN: 1069-8299
    Schlagwort(e): mixed harmonic element ; shells of revolution ; consistent stress parameters ; Engineering ; Numerical Methods and Modeling
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Mathematik , Technik allgemein
    Notizen: A simple and efficient three-noded mixed harmonic axisymmetric element for shells of revolution under non-symmetric loading is developed. The present element considering shear strain is based on a modified mixed variational principle in which the independent unknowns are only the quantities prescribable at the shell edges. The non-symmetric variations of the displacements and stress resultants in the circumferential direction are decomposed in terms of Fourier series. The stress resultants are eliminated on the element level so that the standard stiffness equations are obtained. The importance of consistent stress parameters is addressed and the efficiency of the present consistent mixed element is shown. © 1997 John Wiley & Sons, Ltd.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    A finite element formulation with stabilization matrix for geometrically non-linear shells (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1703-1720 
    Details
    ISSN: 0029-5981
    Schlagwort(e): Engineering ; Engineering General
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Mathematik , Technik allgemein
    Notizen: An assumed strain finite element formulation with a stabilization matrix is developed for analysis of geometrically non-linear problems of isotropic and laminated composite shells. The present formulation utilizes the degenerate solid shell concept and assumes an independent strain as well as displacement. The assumed independent strain field is divided into a lower order part and a higher order part. Subsequently, the lower order part is set equal to the displacement-dependent strain evaluated at the lower order integration points and the remaining higher order part leads to a stabilization matrix. The strains and the determinant of the Jacobian matrix are assumed to vary linearly in the thickness direction. This assumption allows analytical integration through thickness, independent of the number of plies. A nine-node element with a judiciously chosen set of higher order assumed strain field is developed. Numerical tests involving isotropic and composite shells undergoing large deflections demonstrate the validity of the present formulation.
    Zusätzliches Material: 13 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/nme.1620330810
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  • 8
    Digitale Medien
    Digitale Medien
    A SIMPLE AND EFFICIENT MIXED FINITE ELEMENT FOR AXISYMMETRIC SHELL ANALYSIS (1996)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 39 (1996), S. 1903-1914 
    Details
    ISSN: 0029-5981
    Schlagwort(e): axisymmetric shell ; mixed finite element ; Engineering ; Engineering General
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Mathematik , Technik allgemein
    Notizen: An efficient, perhaps simplest, three-noded mixed finite element is proposed for axisymmetric shell analysis. The key feature in the present formulation is to start with a better variational principle in which the independent unknowns are only the quantities that can be prescribed at the shell edges. If the consistency for field approximations is satisfied, no other numerical consideration is necessary in the present element. Several examples confirm the satisfactory numerical behaviour of the present mixed element.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
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  • 9
    Digitale Medien
    Digitale Medien
    A taylor weak-statement algorithm for hyperbolic conservation laws (1987)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 7 (1987), S. 489-520 
    Details
    ISSN: 0271-2091
    Schlagwort(e): CFD Algorithm ; Weak Statement ; Hyperbolic ; Parabolic ; Dissipation ; Dispersion ; Engineering ; Engineering General
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Notizen: Finite element analysis, applied to computational fluid dynamics (CFD) problem classes, presents a formal procedure for establishing the ingredients of a discrete approximation numerical solution algorithm. A classical Galerkin weak-statement formulation, formed on a Taylor series extension of the conservation law system, is developed herein that embeds a set of parameters eligible for constraint according to specification of suitable norms. The derived family of Taylor weak statements is shown to contain, as special cases, over one dozen independently derived CFD algorithms published over the past several decades for the high speed flow problem class. A theoretical analysis is completed that facilitates direct qualitative comparisons. Numerical results for definitive linear and non-linear test problems permit direct quantitative performance comparisons.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/fld.1650070505
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  • 10
    Digitale Medien
    Digitale Medien
    On a finite element CFD algorithm for compressible, viscous and turbulent aerodynamic flowsBased as an invited lecture. (1987)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 7 (1987), S. 1235-1259 
    Details
    ISSN: 0271-2091
    Schlagwort(e): Fluid Mechanics ; CFD ; Finite Element ; Accuracy/Convergence ; Stability ; PNS/TLNS ; Turbulent ; Engineering ; Engineering General
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Notizen: This paper develops and analyses individual construction aspects of an efficient and accurate finite element algorithm for prediction of viscous and turbulent flow fields of impact in aerodynamics. The theoretical construction employs a Taylor weak statement (TWS) for coincident embedding of stability mechanisms within a classic Galerkin finite element formulation of semi-discrete approximation error orthogonalization. A wide variety of the stabilizing mechanisms of independently derived CFD algorithms are contained within the TWS theory. An implicit construction that meets the requirement of efficient convergence to steady state is developed. The theoretical asymptotic error estimates of the TWS finite element algorithm for supersonic and viscous boundary layer flows are verified. Application to a three-dimensional turbulent flow is cited.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/fld.1650071107
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