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81.
Dr.-Ing. B. Petri Dr.-Ing. A. Delgado Prof. Dr.-Ing. H. J. Rath 《Archive of Applied Mechanics (Ingenieur Archiv)》1991,61(6-7):404-413
Übersicht Die hier vorgestellten Ergebnisse sind Teil eines Forschungsprojektes mit dem Ziel, Marangonikonvektion unter Schwerelosigkeit mittels transienter Temperaturfelder zu beeinflussen. In dieser Veröffentlichung werden Lösungen für stationäre Strömungsfelder unter Vorgabe des Temperaturfeldes an der Oberfläche eines frei schwebenden Tropfens präsentiert. In der bestehenden Literatur wird zur Berechnung dieser Ergebnisse die freie Oberfläche des Tropfens als nicht deformierte Kugel vorgegeben. Im Vergleich dazu ergibt sich die Oberfläche in den hier vorgestellten Ergebnissen als Teil der Lösung. Das Strömungsfeld im Tropfen wird für verschiedene Reynolds-Zahlen 0Re5000 und Kapillarzahlen 10Ca1000 dargestellt.
Thermal Marangoni convection in drops under microgravity taking into account their deformation
Summary The investigations presented here are part of a microgravity project in which the reduction of thermal Marangoni convection by using a transient heat source is studied experimentally and theoretically. This publication shows the results of the theoretical considerations concerning steady state fluid motion in a drop under microgravity induced by a given temperature field at the surface of the drop. In contrast to the literature where the surface is assumed to be an underformed sphere the position of the surface is part of the solutions obtained. The solutions have been computed for Reynolds numbers 0Re5000 and capillary numbers 10Ca1000.相似文献
82.
Erlin Sapei Petri Uusi-Kyyny Kari I. Keskinen Juha-Pekka Pokki Ville Alopaeus 《Fluid Phase Equilibria》2010
Isothermal vapor–liquid equilibrium (VLE) of the following systems was measured with a recirculation still: 1-butanethiol + methylcyclopentane at 343.15 K, 1-butanethiol + 2,2,4-trimethylpentane at 368.15 K, 3-methylthiophene + toluene at 383.15 K, 3-methylthiophene + o-xylene at 383.15 K, and 3-methylthiophene + 1,2,4-trimethylbenzene at 383.15 K. 1-Butanethiol + methylcyclopentane and 1-butanethiol + 2,2,4-trimethylpentane systems exhibit positive deviation from Raoult's law, whereas systems containing 3-methylthiophene in aromatic hydrocarbons exhibit only slight positive deviation from Raoult's law. A maximum pressure azeotrope was found in the system 1-butanethiol + 2,2,4-trimethylpentane (x1 = 0.548, P = 100.65 kPa, T = 368.15 K). The experimental results were correlated with the Wilson model and compared with original UNIFAC and COSMO-SAC predictive models. Raoult's law can be used to describe the behavior of 3-methylthiophene in aromatic hydrocarbons at the experimental conditions in this work. Liquid and vapor-phase composition were determined with gas chromatography. All measured data sets passed the thermodynamic consistency tests applied. The activity coefficients at infinite dilution are also presented. 相似文献
83.
R.M. Clark K.E. Gregorich J.S. Berryman M.N. Ali J.M. Allmond C.W. Beausang M. Cromaz M.A. Deleplanque I. Dragojevi? J. Dvorak P.A. Ellison P. Fallon M.A. Garcia J.M. Gates S. Gros H.B. Jeppesen D. Kaji I.Y. Lee A.O. Macchiavelli K. Morimoto H. Nitsche S. Paschalis M. Petri L. Stavsetra F.S. Stephens H. Watanabe M. Wiedeking 《Physics letters. [Part B]》2010
We report results from an experiment on the decay of the high-K isomers in 254No. We have been able to establish the decay from the known high-lying four-quasiparticle isomer, which we assign as a Kπ=16+ state at an excitation energy of Ex=2.928(3) MeV. The decay of this state passes through a rotational band based on a previously unobserved state at Ex=2.012(2) MeV, which we suggest is based on a two-quasineutron configuration with Kπ=10+. This state in turn decays to a rotational band based on the known Kπ=8− isomer, which we infer must also have a two quasineutron configuration. We are able to assign many new gamma-rays associated with the decay of the Kπ=8− isomer, including the identification of a highly K-forbidden ΔK=8 E1 transition to the ground-state band. These results provide valuable new information on the orbitals close to the Fermi surface, pairing correlations, deformation and rotational response, and K-conservation in nuclei of the deformed trans-fermium region. 相似文献
84.
A novel strategy for the synthesis of (1-alkanoyloxy-4-alkanoylaminobutylidene)-1,1-bisphosphonic acid derivatives (1a-d) via (1-hydroxy-4-alkanoylaminobutylidene)-1,1-bisphosphonic acid derivatives (2a-d), starting from alendronate has been developed with reasonable 51-77% overall yields. Intermediate products, (1-hydroxy-4-alkanoylaminobutylidene)-1,1-bisphosphonic acid derivatives (2a-d), were prepared in water with reasonable to high yields (52-94%). 相似文献
85.
Pereira EM Petri DF Carmona-Ribeiro AM 《The journal of physical chemistry. B》2006,110(20):10070-10074
The effect of monovalent salt nature and concentration over a range of low ionic strengths (0-10 mM LiCl, NaCl, KCl, or CsCl) and at two different pH values (6.3 and 10.0) on adsorption of dioctadecyldimethylammonium bromide (DODAB) bilayer fragments (BF) onto flat SiO(2) surfaces was systematically evaluated by means of in situ ellipsometry. High-affinity adsorption isotherms fitted by the Langmuir model indicated that adsorption maxima were consistent with bilayer deposition only around 10 mM monovalent salt at both pH values. In pure water, the mean thickness of the DODAB adsorbed layer was close to zero with bilayer deposition taking place only around 10 mM ionic strength. In the presence of 10 mM CsCl or LiCl, the highest and the lowest affinity constants for DODAB adsorption onto SiO(2) were, respectively, obtained consistently with the expected facility of cation exchange at the surface required for DODAB adsorption. The cation more tightly bound to the solid surface should be Li(+), which would present the largest resistance to displacement by the DODAB cation, whereas the less tightly bound cation should be Cs(+) due to its largest ionic radius and lowest charge density. In other words, DODAB adsorption proceeds in accordance with charge density on the solid surface, which depends on the nature and concentration of bound counterions as well as DODAB cation ability to displace them. AFM images show a very smooth DODAB film adsorbed onto the surface in situ with a large frequency of BF auto-association from their edges. The present results for flat surfaces entirely agree with previous data from our group for DODAB adsorption onto silica particles. 相似文献
86.
K. Petri 《Mathematische Annalen》1923,88(3-4):242-289
Ohne Zusammenfassung 相似文献
87.
Claudia Dell’Era Petri Uusi-Kyyny Juha-Pekka PokkiMinna Pakkanen Ville Alopaeus 《Fluid Phase Equilibria》2010
The solubility of carbon dioxide in aqueous solutions of alkanolamines was measured by means of two experimental methods. The solubility of carbon dioxide was measured at 298 K with a static total pressure apparatus in solutions of water + diisopropanolamine (DIPA) having mass fraction of DIPA equal to 10.1%, 11.0% and 33.9%. The density of the water + DIPA solution was measured continuously during the experiments to investigate the changes in density introduced by the absorption of carbon dioxide. A correlation for the density of CO2-loaded aqueous solutions of DIPA is presented. 相似文献
88.
K. Micko G. Kappeler R. Schulze und W. Petri 《Fresenius' Journal of Analytical Chemistry》1913,52(7-8):499-504
Ohne Zusammenfassung 相似文献
89.
A. Chaston Chapmann Hlasiwetz Nietzke und Petri 《Fresenius' Journal of Analytical Chemistry》1912,51(7-8):513-514
Ohne Zusammenfassung 相似文献
90.
The relative thermodynamic stabilities of 4,7-dihydro-1,3-dioxepin (4,6-dioxacycloheptene, 1a) and 4,5-dihydro-1,3-dioxepin (3,5-dioxacycloheptene, 1b), and of a number of their 2-substituted derivatives, have been determined by base-catalyzed chemical equilibration in DMSO solution. Without exception, the 4,5-dihydro isomer is the dominating species at thermodynamic equilibrium. The relative stability of the b form is promoted by the presence of a single alkyl group on C-2, whereas two alkyl groups on C-2 have an opposite effect. In general, the thermodynamic parameters H
m
and
Sm
, of isomerization vary unexpectedly with the pattern of substitution at C-2. These trends appear to be derived from significant substituent-induced conformational changes in the b isomer, as suggested by 13C and 17O NMR chemical shift data. 相似文献