Absolute Viscosity of Air down to Cryogenic Temperatures and up to High Pressures

1973 ◽  
Vol 15 (4) ◽  
pp. 266-270 ◽  
Author(s):  
B. Latto ◽  
M. W. Saunders
Keyword(s):  
Experimental Data ◽  
High Pressure ◽  
Atmospheric Pressure ◽  
High Pressures ◽  
The Other ◽  
Cryogenic Temperatures ◽  
Temperature Range ◽  
Absolute Viscosity ◽  
Correlating Equations ◽  
Better Than

The absolute viscosity of gaseous air was determined experimentally for the general pressure and temperature range 100–15 000 kPa and 90–400 K respectively, using a series capillary transpiration-type viscometer which has been developed by the authors. The accuracy of the experimental data is believed to be better than ± 1 per cent. Two general correlating equations, one for atmospheric pressure and the other for medium high pressure (i.e., densities up to 400 kg/m3), have been obtained.

The Rate-Constant for the Recombination of Methyl Radicals

1986 ◽  
Vol 39 (8) ◽  
pp. 1257 ◽  
Author(s):  
NL Arthur ◽  
JC Biordi
Keyword(s):  
Experimental Data ◽  
High Pressure ◽  
Rate Constant ◽  
Rate Constants ◽  
The Other ◽  
Methyl Radicals ◽  
Experimental Conditions ◽  
Temperature Range ◽  
Best Value ◽  
Limiting Value

Rate constants for the recombination of CH3 radicals have been measured by means of the rotating sector technique in the temperature range 373- 463 K, and at a pressure of 30 Torr . CH3 radicals were produced by the photolysis of acetone, and the experimental data were fitted to sector curves generated from Shepp's theory. The results give kb = (2.81�0.22)×1013 cm3 mol-1 s-1, which, under the chosen experimental conditions, is close to its high-pressure limiting value. A comparison is made with the other values of the rate constant reported in the literature, and a best value is suggested.

Thermal Model of a Thinned-Die Cooling System

2003 ◽  
Author(s):  
N. Boiadjieva ◽  
P. Koev
Keyword(s):  
Experimental Data ◽  
Thermal Model ◽  
Cooling System ◽  
Input Power ◽  
The Other ◽  
System Parameters ◽  
Air Intake ◽  
Optical Probing ◽  
Cooling Air ◽  
Better Than

For through-silicon optical probing of microprocessors, the heat generated by devices with power over 100W must be dissipated [1]. To accommodate optical probing, a seemingly elaborate cooling system that controls the microprocessor temperature from 60 to 100° C for device power up to 150W was designed [2]. The system parameters to achieve the desired thermal debug environment were cooling air temperature and air flow. A mathematical model was developed to determine both device temperature and input power. The 3-D heat equation that governs the temperature distribution was simplified to a case of a 1-D rod with one end at the device center and the other at the cooling air intake. Thus the cooling system was reduced to an analytical expression. From experimental data, we computed all coefficients in the model, then ran extensive tests to verify—the accuracy was better than 10% over the entire temperature and power ranges.

scholarly journals Thermophysical Properties of 1-Butanol at High Pressures

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5046
Author(s):  
Marzena Dzida
Keyword(s):  
Speed Of Sound ◽  
Thermophysical Properties ◽  
High Pressures ◽  
Fuel Additive ◽  
Temperature Range ◽  
Isobaric Thermal Expansion ◽  
Isentropic And Isothermal Compressibilities ◽  
Overlap Method ◽  
Pulse Echo ◽  
Better Than

1-Butanol can be considered as a good fuel additive, which can be used at high pressures. Therefore, the knowledge of high-pressure thermophysical properties is crucial for this application. In this paper, new experimental data on the speed of sound in 1-butanol in the temperature range from 293 to 318 K and at pressures up to 101 MPa are reported. The speed of sound at a frequency of 2 MHz was measured at atmospheric and high pressures using two measuring sets operating on the principle of the pulse–echo–overlap method. The measurement uncertainties were estimated to be better than ±0.5 m·s−1 and ± 1 m·s−1 at atmospheric and high pressures, respectively. Additionally, the density was measured under atmospheric pressure in the temperature range from 293 to 318 K using a vibrating tube densimeter Anton Paar DMA 5000. Using the experimental results, the density and isobaric and isochoric heat capacities, isentropic and isothermal compressibilities, isobaric thermal expansion, and internal pressure were calculated at temperatures from 293 to 318 K and at pressures up to 100 MPa.

scholarly journals Designing of a double-cylinder viscometer for high-pressure liquids

2020 ◽  
Vol 53 (7-8) ◽  
pp. 1482-1492
Author(s):  
Shuo Liu ◽  
Chenguang Xu ◽  
Tongqi Liu ◽  
Yong Cai
Keyword(s):  
Experimental Data ◽  
High Pressure ◽  
Atmospheric Pressure ◽  
Pressure Range ◽  
Magnetic Coupling ◽  
Normal Pressure ◽  
Friction Torque ◽  
Viscosity Measurement ◽  
Closed Cavity ◽  
Cylinder Viscometer

In this work, a double-cylinder viscometer is designed to measure dynamic viscosity over a pressure range from atmospheric pressure up to 150 MPa and a temperature range of 278.15–333.15 K. A high-pressure closed cavity is designed innovatively and the magnetic coupling is adopted to transfer the torque to reduce the friction; the inner cylinder with ruby bearing is designed to reduce the friction torque, thus the accuracy of the viscosity measurement is improved. The experiment of measuring the standard viscosity liquid (N10 and N35) under normal pressure and measuring the viscosity of methylbenzene under the pressure of 0.1–150 MPa were carried out, and considering all the experimental data, the uncertainty of the viscosity measurements is approximately ±3%.

Some high-pressure pyroxenes

1974 ◽  
Vol 39 (307) ◽  
pp. 768-787 ◽  
Author(s):  
R. N. Thompson
Keyword(s):  
High Pressure ◽  
Alkali Basalt ◽  
High Pressures ◽  
Major Element ◽  
Distribution Coefficients ◽  
The Other ◽  
Strong Negative Correlation ◽  
Complex Behaviour ◽  
Complex Variation ◽  
Bulk Chemistry

SummaryMicroprobe analyses of Ca-rich pyroxenes crystallized in the melting ranges of a magnesian alkali basalt, a transitional basalt, an olivine tholeiite, a tholeiitic andesite, and an augite leucitite at pressures between 8 and 45 kb show complex variation. Ca-poor pyroxene precipitated only from the alkali basalt at pressures between 14 and 18 kb. Pyroxene falling near the Di-Hed join in the pyroxene quadilateral formed at all pressures and temperatures from the leucitite, whereas ‘Ca-rich’ pyroxene crystallizing from the other four compositions was Ca-poor augite to sub-calcic augite. The liquidus Ca-rich pyroxenes all show rising Al and Na and falling Ti with increasing pressure and temperature. Other elements show complex behaviour; all but the leucitite pyroxenes tend to make temporary excursions of solid solution towards Ca-poor pyroxene at intermediate pressures, returning to more Ca-rich compositions at high pressures. At sub-liquidus temperatures Na and Ti consistently rise with falling T at constant P and also with rising P at constant T in these pyroxenes. The behaviour of the other elements in these circumstances depends on the nature of the coexisting phases.Fe/Mg distribution between Ca-rich pyroxene and liquid, in the form has a constant value of 0.29 for three separate bulk compositions at widely differing temperatures and pressures. Distribution coefficients for Mg and Fe between pyroxenes and coexisting garnets at high pressures are very similar to those found in garnet pyroxenite xenoliths from Oahu, Hawaii. Systematic shifts in the apparent stoichiometry (all Fe taken as Fe2+) of the augite leucitite pyroxenes are thought to indicate that they have considerable Fe3+ contents at low pressure, decreasing as P rises. If so, they show a strong negative correlation between Na and Fe3+, which negates the customary practice of forming acmite before jadeite component when recalculating the analyses of high-pressure pyroxenes.The sets of pyroxenes crystallized from each composition show consistent trends when plotted on such diagrams as jadeite vs Ca-Tschermak's ‘molecule’, which have often been used in attempts to discriminate natural pyroxenes formed in differing P-T environments. However, these new data show clearly that the bulk chemistry of the magma has a predominating influence on the composition of the pyroxenes crystallizing from it. Unless it is certain that a suite of natural pyroxenes have all precipitated from the same magma, it is probably pointless to attempt to deduce the relative P-T conditions of their formation from their major element chemistry.

scholarly journals NICKEL BIOSORPTION BY FINELY GROUND WASTE SLUDGE / NIKELIO BIOSORBAVIMAS SMULKIAI SUMALTU NUOTEKŲ DUMBLU / БИОСОРБЦИЯ НИКЕЛЯ МЕЛКО ИЗМЕЛЬЧЕННЫМ ИЛОМ СТОКОВ

2011 ◽  
Vol 19 (3) ◽  
pp. 208-214 ◽  
Author(s):  
Yasser Hannachi
Keyword(s):  
Experimental Data ◽  
Langmuir Isotherm ◽  
Treatment Plant ◽  
Second Order ◽  
The Other ◽  
Biosorption Capacity ◽  
Waste Sludge ◽  
Order Rate ◽  
Kinetics Of ◽  
Better Than

In this paper, removal of Ni (II) from aqueous solution by finely ground waste sludge (FGWS) was investigated. Waste sludge samples obtained from a varnishes and lacquers industry wastewater treatment plant was dried, ground and pre-treated with 1% H2O2 to improve the biosorption capacity. Kinetics of nickel biosorption onto FGWS was investigated by using the FGWS samples with particle size of 62.2 µm. The pseudo-first and second order rate expressions were used to correlate the experimental data. The kinetic constants were determined for both models and the second order rate expression was found to be more suitable. Three different biosorption isotherms were used to correlate the equilibrium biosorption data and the isotherm constants were determined. The Langmuir isotherm was found to fit the experimental data better than the other tested isotherms. The biosorption capacity (qm) and saturation constant (K) for the Langmuir isotherm showed that finely ground waste sludge has the largest capacity and affinity for removal of Ni(II) compared to the other Activated sludges. Santrauka Nagrinėjami Ni(II) šalinimo iš vandeninių tirpalų smulkiai sumaltu nuotekų dumblu (SSND) tyrimų rezultatai. Nuotekų dumblo pavyzdžiai imti iš glazūravimo ir lakavimo pramonės nuotekų valymo įrenginių, išdžiovinti, susmulkinti ir apdoroti 1% H2O2, kad padidėtų biosorbcijos tūris. Nikelio sorbcijos SSND kinetika tirta naudojant SSND bandinius, kurių dalelių dydis 62,2 µm. Pseudo pirmojo ir antrojo laipsnio greičio išraiškos buvo taikomos eksperimentinių duomenų koreliacijai apibrėžti. Kinetinė konstanta nustatyta abiejų modelių, tačiau antrojo laipsnio greičio išraiška buvo tinkamesnė. Pagal tris skirtingas biosorbcijos izotermes nustatyta biosorbcijos pusiausvyros duomenų koreliacija, rastos izotermių konstantos. Langmiuro (Langmuir) izotermė geriau atitiko eksperimentinius duomenis nei kitos tirtosios izotermės. Pagal Langmiuro izotermę biosorbcijos geba (q m) ir prisotinimo konstanta (K) rodė, kad smulkiai sumalto nuotekų dumblo geba šalinti Ni(II) yra didžiausia, palyginti su kitos rūšies aktyvintojo dumblo. Резюме Исследуется удаление Ni(II) из водных растворов мелко измельченным илом стоков (МИИС). Образцы ила стоковбыли взяты из оборудования по очистке стоков в промышленности по глазурованию и лакованию. Затем образцы были высушены, измельчены и обработаны 1-процентным H2O2, с целью увеличить объем биосорбции. Кинетика сорбции никеля МИИС исследовалась с применением образцов МИИС, величина частиц которых составляла62,2 μм. Выражения скорости псевдопервой и псевдовторой степени использовались для определения корреляции экспериментальных данных. Кинетическая константа была установлена для обеих моделей. Однако выражение скорости второй степени оказалось более приемлемым. Три разные изотермы биосорбции применялись для определения корреляции данных по равновесию биосорбции и констант изотерм. Изотерма Langmuir лучше совпала с экспериментальными данными, чем другие испытуемые изотермы. Способность биосорбции (q m) изотермы Langmuir и константа насыщения (K) показали, что мелко измельченный ил стоков обладает наибольшей способностью удалять Ni(II) по сравнению с другими видами активированного ила.

Effect of Heat Flux on Droplet Entrainment Using Annular Flow Dryout Model

2010 ◽  
Author(s):  
Masroor Ahmad ◽  
Evgeniy Burlutskiy ◽  
Simon P. Walker ◽  
Geoffrey F. Hewitt
Keyword(s):  
Experimental Data ◽  
Heat Flux ◽  
High Pressure ◽  
Liquid Film ◽  
Annular Flow ◽  
High Pressures ◽  
Droplet Entrainment ◽  
Annular Film ◽  
Low Pressures ◽  
Flow Experiments

Annular film dryout depends upon the competition of entrainment, deposition and evaporation processes between the droplet-laden core and wall liquid film. In this paper, effect of heat flux on droplet entrainment is analyzed by modeling different low and high pressure diabatic annular flow experiments numerically using an annular flow dryout model (AFM). Overall, the AFM predicted the experimental data reasonably accurately. It is concluded that at high pressures increasing heat flux may enhance net entrainment considerably but this effect diminishes at low pressures.

Heat Capacities of Some Alkyl Acetates at 295-323 K

1997 ◽  
Vol 62 (10) ◽  
pp. 1527-1532 ◽  
Author(s):  
Václav Svoboda ◽  
Kornelia Gottmanová ◽  
Vladimír Hynek ◽  
Bohumír Koutek
Keyword(s):  
Experimental Data ◽  
Linear Function ◽  
Atmospheric Pressure ◽  
Heat Capacities ◽  
Group Additivity ◽  
Temperature Range ◽  
Alkyl Acetates

Molar heat capacities Cp,m at constant atmospheric pressure have been determined with a typical uncertainty of about 0.3% for eight liquid alkyl acetates H(CH2)nOCOCH3 (n = 6-12, 14), over the temperature range 295-323 K. The Cp,m values were found to be a linear function of temperature. A comparison of experimental data with those predicted by the group additivity method demonstrated a rather limited capability of the additivity scheme to predict correctly the Cp,m values for higher (n > 10) homologues in the series.

BERICHT: Self-Diffusion in Molten Salts. A Comparison Between Diffusion Theories and Experimental Data

1968 ◽  
Vol 23 (6) ◽  
pp. 933-939
Author(s):  
C.-A. Sjöblom
Keyword(s):  
Experimental Data ◽  
Molten Salts ◽  
Arrhenius Equation ◽  
Local Density ◽  
Cell Model ◽  
The Other ◽  
Self Diffusion ◽  
Free Volume Model ◽  
Hole Model ◽  
Better Than

A comparison between the available self-diffusion data on pure molten salts and the predictions by different liquid diffusion theories is made. It is found that the Arrhenius equation D=D0exp (— Q/R T) describes the experimental data equally well (or better) than any of the other theoretically predicted equations. The hole model prediction (Q=3.74 R Tm) is found to be inaccurate. The free volume model and the local density fluctuation models describe the data less well than the other models considered. The cubic cell model leads to a correct correlation between self-diffusion and kinematic viscosity for several salts (but not all).

scholarly journals Thermal Conductivity of Steam at Atmospheric Pressure

1969 ◽  
Vol 11 (4) ◽  
pp. 392-401 ◽  
Author(s):  
T. J. S. Brain
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Steady State ◽  
Atmospheric Pressure ◽  
Concentric Cylinder ◽  
Temperature Range ◽  
Steady State Method ◽  
New Correlation ◽  
Paper Work ◽  
State Method

In this paper work carried out by the author to measure the thermal conductivity of steam at atmospheric pressure in the temperature range 100-700°C is reported. This work was undertaken in view of the discrepancies which exist in the experimental data at atmospheric pressure. In particular, the serious differences which exist at the high temperatures between the results of Russian experimenters, who give higher values than those given by American and German workers, needed investigation. Utilizing two concentric cylinder cells an absolute steady state method has been used to measure the thermal conductivity of steam in the temperature range 100-700°C, at atmospheric pressure, with a probable accuracy estimated to be within ± l·5-±2 per cent. The results obtained confirm Russian observations at the higher temperatures and it is hoped that these results will help finally to resolve the inconsistencies in the experimental data. A fresh assessment of all the experimental data is given by the author where arguments in favour of both the lower and higher atmospheric lines are discussed. A new correlation of experimental data has been undertaken and a reduction in the tolerances put on the equation defining the atmospheric line from ±3 per cent in the range 100-400°C and ±4 per cent in the range 400-700°C to ±2 per cent over the complete range 100-700°C is now recommended.

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