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11.
The steady flows of a non-Newtonian fluid are considered when the slippage between the plate and the fluid is valid. The constitutive equations of the fluid are modeled by those for an Oldroyd 6-constant fluid. They give rise to non-linear boundary value problems. The analytical solutions are obtained using powerful, easy-to-use analytic technique for non-linear problems, the homotopy analysis method. It is shown that solutions exist for all values of non-Newtonian parameters. The solutions valid for no-slip condition for all values of non-Newtonian parameters can be derived as the special cases of the present analysis. Finally, graphs are plotted and critical assessment is made for the cases of slip and no-slip conditions. 相似文献
12.
Hyperfine Interactions - The 57Fe Mössbauer spectra recorded in situ from 5% ruthenium-doped maghemite show parameters typical for maghemite up to 600 K and a hyperfine field distribution... 相似文献
13.
Multi‐switching combination–combination synchronization of non‐identical fractional‐order chaotic systems 下载免费PDF全文
In this paper, multi‐switching combination–combination synchronization scheme has been investigated between a class of four non‐identical fractional‐order chaotic systems. The fractional‐order Lorenz and Chen's systems are taken as drive systems. The combination–combination of multi drive systems is then synchronized with the combination of fractional‐order Lü and Rössler chaotic systems. In multi‐switching combination–combination synchronization, the state variables of two drive systems synchronize with different state variables of two response systems simultaneously. Based on the stability of fractional‐order chaotic systems, the multi‐switching combination–combination synchronization of four fractional‐order non‐identical systems has been investigated. For the synchronization of four non‐identical fractional‐order chaotic systems, suitable controllers have been designed. Theoretical analysis and numerical results are presented to demonstrate the validity and feasibility of the applied method. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
14.
Pool boiling from GEWA surfaces in water and R-113 总被引:1,自引:0,他引:1
Pool boiling heat transfer measurements are reported for water and R-113 with several horizontal cylindrical test sections: plain, T-finned GEWA-T (with various gaps) and standard low fin GEWA-K. With R-113 the enhancement is a well-behaved function ofS
T
, reaching a maximum of 2 atS
T
= 0.25 mm. With distilled water, the performance depends in a more complex way on gap width. The maximum enhancement of 1.6 is obtained atS
T
=0.35 mm. Visual observations of the actual test sections and models indicated a complex liquid-vapor exchange mechanism. Bubble generation with adjacent liquid feed was observed at random locations around the periphery of the test section. A semi-theoretical equation was developed which correlates the experimental data quite well.
Nomenclature A surface area - A t tunnel/channel wall area - A liquid film area - C q constant in natural convection correlation - C T constant in GEWA-T Model - D outside diameter - D b base diameter (fin root diameter) - D tc diameter at thermocouple location - h heat transfer coefficient - h fg latent heat - h t heat transfer coefficient at the tunnel wall - k l thermal conductivity of liquid - L length of test section - N A number of active nucleation sites - ql latent heat transfer rate - q heat flux - qex natural convection heat flux - q latent heat flux - S t GEWA-T gap width - T wall-minus-saturation temperature difference - T gn vapor temperature - T s saturation temperature - T w wall temperature - x, y constants in natural convection correlation - liquid film thickness - surface tension Dedicated to Prof. Dr.-Ing. U. Grigull's 75th birthday 相似文献
Sieden bei freier Konvektion von GEWA-Oberflächen in Wasser und R-113
Zusammenfassung Es wird über Wärmeübergangsmessungen beim Sieden unter freier Konvektion mit Wasser und R-113 an verschiedenen zylindrischen, horizontal angeordneten Versuchsobjekten berichtet, die folgende Oberflächenbeschaffenheiten hatten: glatt, T-berippt GEWA-T (mit unterschiedlichen Abständen) und serienmäßig mit niedrigen Rippen versehen GEWA-K. Bei R-113 ist die Verbesserung im Wärmeübergang eine erwartungsgemäße Funktion vonS T , die einen Maximalwert von 2 beiS T =0,25 mm erreicht. Bei destilliertem Wasser hängt das Verhalten in komplizierter For von der Lückenweite ab. Die maximale Verbesserung liegt bei 1,6 und wird fürS T =0,35 mm erreicht. Optische Beobachtungen an den Versuchsobjekten und Modellen zeigten einen komplizierten Flüssigkeits-Dampf-Austauschmechanismus. Es wurde Blasenbildung mit benachbartem Flüssigkeitszustrom an willkürlich wechselnden Stellen um die Peripherie des Versuchsobjektes beobachtet. Eine halbtheoretische Gleichung wurde entwickelt, welche die experimentellen Daten gut wiedergibt.
Nomenclature A surface area - A t tunnel/channel wall area - A liquid film area - C q constant in natural convection correlation - C T constant in GEWA-T Model - D outside diameter - D b base diameter (fin root diameter) - D tc diameter at thermocouple location - h heat transfer coefficient - h fg latent heat - h t heat transfer coefficient at the tunnel wall - k l thermal conductivity of liquid - L length of test section - N A number of active nucleation sites - ql latent heat transfer rate - q heat flux - qex natural convection heat flux - q latent heat flux - S t GEWA-T gap width - T wall-minus-saturation temperature difference - T gn vapor temperature - T s saturation temperature - T w wall temperature - x, y constants in natural convection correlation - liquid film thickness - surface tension Dedicated to Prof. Dr.-Ing. U. Grigull's 75th birthday 相似文献
15.
Avez Sharipov Khurshid Tursunov Sunnatullo Fazliev Bahtigul Azimova Jamoliddin Razzokov 《Molecules (Basel, Switzerland)》2021,26(13)
Horse chestnut (Aesculus hippocastanum L.)-derived drugs have shown their potential in biomedical applications. The seed of A. hippocastanum contains various kinds of chemical compounds including phenolics, flavonoids, coumarins, and triterpene saponins. Here, we investigated the chemical components in A. hippocastanum L. grown in Uzbekistan, which has not yet been studied in detail. We identified 30 kinds of triterpene saponins in an extract of A. hippocastanum L. Classifying extracted saponins into eight fractions, we next studied the hypoglycemic and the anti-inflammatory activities of escin and its derivatives through in vivo experiments. We came by data indicating the highest (SF-1 and SF-2) and the lowest (SF-5 and SF-8) antidiabetic and anti-inflammatory effects of those eight fractions. These results imply the prospective use of A. hippocastanum L. grown in Uzbekistan in the production of pharmaceutical drugs to treat diabetes and inflammation. 相似文献
16.
H. R. Velasco J. J. Ayub M. Belli U. Sansone 《Journal of Radioanalytical and Nuclear Chemistry》2006,268(3):503-509
Summary Interaction matrices, an expert semi quantitative method to identify multiple interactions among biotic and abiotic components
of the ecosystem can be considered as a useful tool to develop conceptual models of the behavior of radionuclides in the environment.
This systematic approach facilitates a comprehensible identification of the pathways of the main radionuclides and permits
classification of the role of different ecosystem components in terms of cause-effect relationships. The method was applied
to study the radiocesium migration in grassland ecosystem affected by the Chernobyl 137Cs deposition. Interaction matrices have been simultaneously utilized to explore the dynamic changes on the radiocesium migration
pathways and to compare the consequences of the various radiation exposure paths to living organisms. 相似文献
17.
The problem of unsteady free convection flow is considered for the series solution (analytic solution). The flow is induced
by an infinite vertical porous plate which is accelerated in its own plane. The series solution expressions for velocity field,
temperature field and concentration distribution are presented. The influence of important parameters is seen on the velocity,
temperature, concentration, skin friction coefficient and temperature gradient with the help of graphs and tables. Convergence
is also properly checked for different values of the important parametes for velocity field, temperature and concentration
with the help of ħ-curves. 相似文献
18.
19.
Khurshid A. Zafar M. N. Javed K. Iqbal N. Arshad M. N. 《Russian Chemical Bulletin》2020,69(11):2121-2128
Russian Chemical Bulletin - A nickel(II) complex with the newly synthesized dicarboxamide ligand [H2LBZ][(CF3SO3)Cl] was explored as a water oxidation catalysis. All the synthesized compounds were... 相似文献
20.
Ayub Khurram Shahzad Zaman Waqas Qamar Miran Waheed Ali Meesam Abbas Zain Mushtaq Umair Shahzad Asif Yang Ji 《Research on Chemical Intermediates》2022,48(10):4227-4248
Research on Chemical Intermediates - Volatile organic compounds (VOCs) represent a very important class of pollutants that causes serious health effects. There is an urgent requirement to establish... 相似文献