scholarly journals Development of Characterization Techniques of Thermodynamic and Physical Properties Applied to the CO2-DMSO Mixture

2009 ◽  
Vol 7 (1) ◽  
Author(s):  
Brice Calvignac ◽  
Elisabeth Rodier ◽  
Jean-Jacques Letourneau ◽  
Jacques Fages
Keyword(s):  
Process Design ◽  
Published Data ◽  
Viscosity Data ◽  
Pressure Measurements ◽  
Co2 Solubility ◽  
Volumetric Expansion ◽  
Characterization Techniques ◽  
Dmso System ◽  
Good Agreement

This work is focused on the development of new characterization techniques of physical and thermodynamic properties. These techniques have been validated using the binary system DMSO-CO2 for which several studies of characterization have been well documented. We focused on the DMSO-rich phase and we carried out measurements of volumetric expansion, density, viscosity and CO2 solubility at 298.15, 308.15 and 313.15 K and pressures up to 9 MPa. The experimental procedures were compared and validated with the available literature data on SC-CO2-DMSO system. We made density and CO2 solubility measurements, using respectively the vibrating tube technology and two static analytical methods. Lastly, we developed an innovative falling body viscosimeter for high pressure measurements. All the measurements made are in good agreement with the already published data in spite of very different experimental techniques. This work is a contribution to the understanding of the DMSO-CO2 binary as it implements new viscosity data. Moreover, it opens new perspectives about the determination of the properties of other systems such as polymers-CO2 and fats-CO2, which are essential for supercritical process design such as extraction, crystallization, chromatography and synthesis reaction.

On the yield stress of geotechnical materials from the slump test

1991 ◽  
Vol 28 (3) ◽  
pp. 457-462 ◽  
Author(s):  
B. Rajani ◽  
N. Morgenstern
Keyword(s):  
Yield Stress ◽  
Undrained Shear Strength ◽  
Bingham Fluid ◽  
Published Data ◽  
Important Class ◽  
Slump Test ◽  
Volcanic Lava ◽  
Undrained Shear ◽  
Good Agreement

There exists an important class of materials, e.g., debris, volcanic lava, sludges, and remoulded sensitive clays, that are known to behave like a Bingham fluid. One of the important properties of a Bingham fluid is the so-called yield stress, and it is usually determined using a coaxial viscometer apparatus. It would be impractical and cumbersome to use this apparatus for many of the materials referred to earlier, and we propose here to examine the use of the slump test. The slump test is used in the concrete industry to evaluate workability and consistency. A statical model is developed to explain the deformation mechanism, and it permits the determination of yield stress. The validity of the statical model is verified using published data on mortar and our own data on Devon silt. The yield stress obtained with the slump test is also compared with the undrained shear strength obtained using the fall cone test. Good agreement is found between the two values. Key words: Bingham fluid, yield stress, slump test, Devon silt.

scholarly journals High Pressure Falling Sinker Liquid Viscosity Determination without Supplementary Density Data: A New Approach

2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Minyu Zeng ◽  
Carl Schaschke
Keyword(s):  
High Pressure ◽  
Published Data ◽  
Viscosity Data ◽  
Liquid Density ◽  
Liquid Viscosity ◽  
New Approach ◽  
Density Data ◽  
Elevated Pressures ◽  
Viscosity Determination

Accurate measurement and determination of liquid viscosity data under high pressure conditions requires knowledge of liquid density data. In this study, a high pressure falling sinker-type viscometer was used to determine the viscosity of n-dodecane at elevated pressures up to 132 MPa without supplementary knowledge of liquid density. The viscometer, which involves the downward movement of a cylindrical sinker under the influence of gravity through the liquid contained within a closed tube, avoided the need for density data by repeating the sinker-timing experiments with two geometrically similar but different-sized sinkers thereby allowing the liquid density in the associated formulae to be eliminated. Furthermore, it was possible to subsequently derive liquid density. Both viscosity and density data were compared to published data for which good correlation was found for viscosity. To minimize errors, it is suggested that the two sinkers for such an approach should be of sufficiently differing densities.

Determination of Unsaturation in Butyl Rubber

1945 ◽  
Vol 18 (4) ◽  
pp. 887-895 ◽  
Author(s):  
John Rehner ◽  
Priscilla Gray
Keyword(s):  
Polymer Solution ◽  
Butyl Rubber ◽  
Negative Slope ◽  
Viscosity Data ◽  
Routine Work ◽  
Simple Extrapolation ◽  
End Group ◽  
Degraded Polymer ◽  
Good Agreement

Abstract In a recent publication on unsaturation in Butyl rubber it was pointed out that, of the various methods that had been examined, ozone degradation at the double bonds appears to give the most reliable unsaturation data, the values based on the limiting viscosity of the degraded polymer being in reasonably good agreement with those determined by end-group analyses. This paper describes in some detail the analytical method, together with certain modifications that have been introduced with the aim of facilitating routine work. It was recognized that the earlier procedure had the disadvantage of being too time-consuming, owing mainly to the steps in which the degraded polymer solution is evaporated to dryness, and the residue redissolved in diisobutylene before the viscosity measurement. An obvious possible improvement was to develop a procedure whereby the polymer solution could be ozonized and the viscosity of the degraded solution determined directly, thus eliminating evaporation and transfer to a second solvent. It was first necessary, however, to perform the experiments described below; their significance will be explained in the sequel. A further simplification was introduced through the use of carbon tetrachloride of ordinary reagent grade instead of the highly purified solvent. While this substitution usually leads to viscosity-time curves displaying a small negative slope in the region where the purified solvent gives unchanged viscosity values, a simple extrapolation to zero time gives viscosity data that are satisfactory within the limits inherent in the method. In view of the practical requirements of the method and the magnitude of the experimental error, the extra time and effort involved in further purification of the solvent appear to be unwarranted.

scholarly journals Investigation of ribonuclease-catalysed kinetics by a micro-calorimetric method

1976 ◽  
Vol 153 (1) ◽  
pp. 89-91 ◽  
Author(s):  
M Tribout ◽  
S Paredes ◽  
J Léonis
Keyword(s):  
Ribonuclease A ◽  
Calorimetric Method ◽  
Published Data ◽  
Enzymic Hydrolysis ◽  
Cyclic Phosphates ◽  
Hydrolysis Of ◽  
Cyclic Cmp ◽  
Step Mechanism ◽  
Good Agreement

A rapid micro-calorimetric method for the simultaneous determination of the Michaelis-Menten parameters and the enthalpy of enzymic reactions is developed. The hydrolysis of 2‘: 3’-cyclic CMP by ribonuclease A is studied to test the proposed method; values obtained are in good agreement with already published data. Enzymic hydrolysis of yeast RNA, unlike that of cyclic phosphates, is shown to be endothermic. This result is explained by the two-step mechanism of this reaction.

Application of an Improved Model for the Determination of Acoustic Resonances in Indicator Passages for Combustion Pressure Measurements

2006 ◽  
Author(s):  
Christoph Gosweiller ◽  
Bryan Willson ◽  
Thomas Walter
Keyword(s):  
Experimental Data ◽  
Base Line ◽  
Pressure Measurements ◽  
Pipe Model ◽  
Reference Transducer ◽  
Acoustic Resonances ◽  
Organ Pipe ◽  
Improved Model ◽  
Good Agreement

The acoustic resonances in indicator passages are often modeled using either a Helmholtz or a so called organ pipe acoustical model. However, in practice these models often indicate natural frequencies which are too high. This paper proposes the Bergh and Tijdeman model [1] which is more accurate and which was originally developed for pressure measurements in turbomachinery. This paper presents the theoretical basis for the Berg / Tijdeman model and then uses it to explore signal distortion from a variety of indicator passage geometries. In order to validate the approach, a flush-mounted water-cooled Kistler reference transducer was used to measure accurate in-cylinder combustion data in an automotive Diesel engine. An additional sensor was recess mounted with passages of different geometries. The Bergh Tijdeman model was then applied to investigate the acoustic distortion of the indicator passages. The results show excellent agreement with the experimental data, which are much closer than using the Helmholtz or the organ pipe model. Further the Bergh and Tijdeman model is applied to complex indicator passage geometries with multiple cavities. Again, for comparison, a flush-mounted Kistler reference transducer was used to measure accurate in-cylinder combustion data in a large-bore natural gas engine. Three additional sensors were mounted using different indicator passage geometries. The engine was operated under base line and knocking combustion conditions. The Bergh Tijdeman model was then applied to model the acoustic distortion of the three indicator passages and again showed good agreement with the experimental data. Finally, the paper proposes simple rules for implementing indicator passages in large gas engines.

COMPARATIVE ACTION OF VARIOUS OESTROGENIC COMPOUNDS ON MOUSE VAGINAL SIALIC ACIDS (II)

1969 ◽  
Vol 62 (4) ◽  
pp. 663-670 ◽  
Author(s):  
Lars Carlborg
Keyword(s):  
Sialic Acid ◽  
Response Curve ◽  
Sialic Acids ◽  
Clear Cut ◽  
Suitable Parameter ◽  
Sufficient Degree ◽  
Comparative Action ◽  
Relative Potencies ◽  
Good Agreement

ABSTRACT Oestrogens administered in lower doses than necessary to induce full cornification of the mouse vagina induce mucification. It was shown previously that the degree of mucification could be estimated by quantitative determination of sialic acids. A suitable parameter for oestrogen assay was the measurement of vaginal sialic acid concentration which exhibited a clear cut dose response curve. Eleven assays of various oestrogens were performed with this method. Their estimated relative potencies were in good agreement with other routine oestrogen assays. A statistically sufficient degree of precision was found. The sensitivity was of the same order, or slightly higher, than the Allen-Doisy test.

Viscosity of Diluted Aqueous K2CO3/KHCO3 Solutions

1992 ◽  
Vol 57 (9) ◽  
pp. 1879-1887 ◽  
Author(s):  
Zdeněk Palatý
Keyword(s):  
Dynamic Viscosity ◽  
Correlation Equation ◽  
Viscosity Data ◽  
Electrolyte Mixtures ◽  
Interaction Coefficients ◽  
Basic Solutions ◽  
Good Agreement

The applicability of the equation derived for calculating the dynamic viscosity of ternary non-electrolyte mixtures, to the correlation of viscosity data of the H2O- K2CO3/KHCO3 system is verified in this work. It was found out that the values of dynamic viscosity obtained experimentally are in good agreement with the viscosity values calculated from this equation. The equation constants - interaction coefficients - were determined from the measurements of dynamic viscosity on mixing the basic solutions of K2CO3 and KHCO3 of known concentration. The correlation equation makes it possible to calculate viscosity of the K2CO3/KHCO3 solutions in the K2CO3 and KHCO3 concentration range from 0 to about 2.0 kmol m-3.

An Automated Method for the Determination of Serum Calcium with Glyoxal Bis (2-Hydroxyanil)

1967 ◽  
Vol 13 (6) ◽  
pp. 515-520 ◽  
Author(s):  
Genevieve Farese ◽  
Janice L Schmidt ◽  
Milton Mager
Keyword(s):  
Serum Calcium ◽  
Automated Analysis ◽  
Automated Method ◽  
Good Agreement

Abstract A completely automated analysis is described for the determination of serum calcium with glyoxal bis (2-hydroxyanil) solution (GBHA). The method is simple and precise, and the data obtained are in good agreement with results obtained by the manual GBHA procedure.

Numerical evaluation of hydrodynamic characteristics of planing hulls by using a hybrid method

2021 ◽  
pp. 147509022199024
Author(s):  
Emre Kahramanoglu ◽  
Silvia Pennino ◽  
Huseyin Yilmaz
Keyword(s):  
Experimental Data ◽  
Hybrid Method ◽  
Design Stage ◽  
Hydrodynamic Characteristics ◽  
Calm Water ◽  
Preliminary Design Stage ◽  
Reduction Function ◽  
Hull Forms ◽  
Good Agreement

The hydrodynamic characteristics of the planing hulls in particular at the planing regime are completely different from the conventional hull forms and the determination of these characteristics is more complicated. In the present study, calm water hydrodynamic characteristics of planing hulls are investigated using a hybrid method. The hybrid method combines the dynamic trim and sinkage from the Zarnick approach with the Savitsky method in order to calculate the total resistance of the planing hull. Since the obtained dynamic trim and sinkage values by using the original Zarnick approach are not in good agreement with experimental data, an improvement is applied to the hybrid method using a reduction function proposed by Garme. The numerical results obtained by the hybrid and improved hybrid method are compared with each other and available experimental data. The results indicate that the improved hybrid method gives better results compared to the hybrid method, especially for the dynamic trim and resistance. Although the results have some discrepancies with experimental data in terms of resistance, trim and sinkage, the improved hybrid method becomes appealing particularly for the preliminary design stage of the planing hulls.

Zur Thermodynamik der hydrophoben Wechselwirkung; die Systeme Wasser + Glycin+ Harnstoff und Wasser + Alanin+ Harnstoff bei 25 °C / Thermodynamics of Hydrophobie Interaction in the Systems Water + Glycin + Urea and Water + Alanin + Urea at 25 °C

1973 ◽  
Vol 28 (9-10) ◽  
pp. 533-554 ◽  
Author(s):  
Lothar Rafflenbeul ◽  
Wa-Ming Pang ◽  
Hansjürgen Schönert ◽  
Klaus Haberle
Keyword(s):  
Amino Acid ◽  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Pressure Measurements ◽  
Free Enthalpy ◽  
Heat Of Dilution ◽  
Ternary Solutions ◽  
Vapor Pressure Measurements ◽  
Calorimetric Determination

Abstract Isopiestic vapor pressure measurements and calorimetric determination of the heat of dilution have been performed and evaluated with respect to enthalpy, entropy and free enthalpy in the ternary solutions water+ glycin+ urea and water+ alanin + urea. The free enthalpy of transfer for the process: Amino acid from water to water+ urea, which can be derived from these measurements, does not agree with the value calculated from solubility measurements. The reason for this discrepancy and the values of entropy and enthalpy in terms of hydrophobic interaction are discussed. Supplementary measurements of the proton magnetic resonance in these solutions are included.

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