Density of water - 2-pyrrolidone mixture a new vibrating tube densimeter from (278.15–323.15) K and up to 70 MPa

A digital vibrating-tube densimeter was constructed for measuring the density of liquids at several temperatures. The underlying principle of the apparatus is the measurement of the period of eigen-vibrations of a V-shaped tube; the second power of the period of the vibrations is proportional to the density of the liquid in the tube. The temperature of the measuring system is controlled by an electronic regulator. The mean error in the density measurement is approximately ±1 . 10-5 g cm-3 at 25 °C and ±2 . 10-5 g cm-3 at 40 °C. The apparatus was used for an indirect measurement of the excess volume, tested with the benzene-cyclohexane system and further used for determining the excess volume of the benzene-methanol, benzene-acetonitrile and methanol-acetonitrile systems at 25 and 40 °C.

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Excess volumes and refractive indices in the benzene-tert-amyl methyl ether and cyclohexane-tert-amyl methyl ether systems at 298.15 K

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19872839 ◽

1987 ◽

Vol 52 (12) ◽

pp. 2839-2843 ◽

Cited By ~ 18

Author(s):

Jan Linek

Keyword(s):

Methyl Ether ◽

Excess Molar Volumes ◽

Excess Volumes ◽

Refractive Indices ◽

Molar Volumes ◽

Vibrating Tube Densimeter ◽

Ether System

Excess molar volumes in the benzene-tert-amyl methyl ether and cyclohexane-tert-amyl methyl ether systems were measured by a vibrating-tube densimeter at 298.15 K and compared with the data for the methanol-tert-amyl methyl ether system determined previously. Besides, the refractive indices in both the systems were measured at the same temperature.

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Ground Transportation: Ships

10.1093/oso/9780198802297.003.0012 ◽

2017 ◽

Author(s):

Peter Rez

Keyword(s):

Speed Of Sound ◽

Projected Area ◽

Drag Coefficients ◽

Wetted Area ◽

Large Container ◽

Density Of Water

The drag on ships comes from movement through the water. There is a part that is analogous to the parasitic drag in aircraft, and a part that comes from creating the bow and stern waves—in some ways similar to the compressibility drag in aircraft that approach the speed of sound. Given that the density of water is more than 800 times that of air, speeds through the water are slower. Drag coefficients are specified differently for ships than for cars, trucks and airplanes. The relevant area is the total wetted area, and not the frontal projected area. Ships can be very efficient—the very powerful two-stroke diesels that power large container ships and tankers can be over 50% thermally efficient.

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Effects of vacuum soaking on the hydration, steaming, and physiochemical properties of japonica rice

Bioscience Biotechnology and Biochemistry ◽

10.1093/bbb/zbaa068 ◽

2021 ◽

Vol 85 (3) ◽

pp. 634-642

Author(s):

Qiuyun Li ◽

Sen Li ◽

Xiao Guan ◽

Kai Huang ◽

Fengbo Zhu

Keyword(s):

Porous Structure ◽

Water Absorption ◽

Microstructure Analysis ◽

Japonica Rice ◽

Starch Granules ◽

Gelatinization Temperature ◽

Relative Crystallinity ◽

Physiochemical Properties ◽

Essential Step ◽

Density Of Water

ABSTRACT Soaking is an essential step in the processing of various rice products. In this study, the influences of vacuum soaking on hydration, steaming, and physiochemical properties of rice were investigated. Results showed that vacuum soaking accelerated water absorption as well as affected the mobility and density of water protons inside rice during soaking. Vacuum soaking could considerably shorten the optimal steaming time from 58 to 32 min and reduce the adhesiveness of steamed rice. Microstructure analysis of rice revealed that porous structure was formed on rice surface and the arrangement of starch granules became loosened after vacuum soaking. Moreover, vacuum soaking slightly reduced the relative crystallinity of rice starches without altering the crystalline type. The gelatinization temperature as well as the peak and trough viscosity was also decreased after vacuum soaking. Our study suggested that vacuum soaking was conducive to improve the soaking and steaming properties of rice.

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The Effect of Magnetic Field on the Hydration of Nanoscopic Hydrophobic N-Alkane Plates

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.228-229.1007 ◽

2011 ◽

Vol 228-229 ◽

pp. 1007-1011

Author(s):

Wei Wei Zhang ◽

Long Qiu Li ◽

Guang Yu Zhang ◽

Hui Juan Dong

Keyword(s):

Magnetic Field ◽

External Magnetic Field ◽

Dynamics Simulation ◽

Free Energy Barrier ◽

Confined Water ◽

Magnetic Exposure ◽

Hydrophobic Solutes ◽

The Magnetic Field ◽

Density Of Water ◽

Induced Adsorption

The effect of an external magnetic field on the hydration behavior of nanoscopic n-octane plates has been extensively investigated using molecular dynamics simulation in an isothermal-isobaric ensemble. The solute plates with different intermolecular spacing have also been considered to examine the effect of the topology of hydrophobic plates on the adsorption behavior of confined water in the presence of an external magnetic field with an intensity ranging from 0.1T to 1 T. The results demonstrate that magnetic exposure decreases the density of water for the plates with intermolecular spacing of a0 = 4 and 5 Å. This suggests that the free energy barrier for evaporation can be lowered by the applied field, and the hydrophobic solutes consisting of condensed n-octane molecules are apt to aggregate in the aqueous solution. In contrast, the magnetic field improves the dissolution or wetting of solutes comprised of loosely packed n-octane plates of a0=7Å. A magnetic-field-induced adsorption-to-desorption translation, which is in agreement with the experimental results provided by Ozeki, has also been observed for the plates with intermolecular spacing of a0 = 6 Å.

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