Volume, expansivity and isothermal compressibility changes associated with temperature and pressure unfolding of staphylococcal nuclease 1 1Edited by C. R. Mathews

Densities of binary mixtures of 1,1,2-trichlorotrifluoroethane + dibromomethane, + bromochloromethane, or + bromotrichloromethane were measured over their entire composition ranges at 288.15 and 308.15 K. Thermal expansion coefficients (α) and excess molar volumes (VEm) were calculated. Moreover, densities at 298.15 K and pressures up to 80 bar (1 bar = 100 kPa) were determined for these same mixtures. Isothermal compressibilities (KT) of the pure liquids and their mixtures were obtained.Key words: density, excess volume, thermal expansion coefficient, isothermal compressibility.

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Developing an Extreme Learning Machine-Based Model for Estimating the Isothermal Compressibility of Biodiesel

International Journal of Chemical Engineering ◽

10.1155/2021/6099019 ◽

2021 ◽

Vol 2021 ◽

pp. 1-7

Author(s):

Yue Wang ◽

Hamid Heydari

Keyword(s):

Fatty Acid ◽

Extreme Learning Machine ◽

Isothermal Compressibility ◽

Fossil Fuels ◽

Methyl Esters ◽

Molecular Structures ◽

Ethyl Esters ◽

Long Chain Fatty Acid ◽

Temperature And Pressure ◽

Learning Machine

Nowadays, the high consumption of fossil fuels has caused many pollutants and environmental problems. Biodiesel has recently been considered as a clean and renewable alternative to fossil fuels. They are found in some molecular structures including fatty acid ethyl esters (FAEEs) and also fatty methyl esters (FAMEs), having various thermophysical characteristics. Thus, it appears essential to select the suitable methods for a particular diesel engine to estimate the ester characteristics. The current research sets out to develop a new and robust method predicting isothermal compressibility of long-chain fatty acid methyl and ethyl esters directly from several basic efficient parameters (pressure, temperature, normal melting point, and molecular weight). Therefore, as a novel and prevailing mathematical method in this field, an extreme learning machine was implemented for isothermal compressibility on the massive dataset. According to statistical evaluations, this novel established model had high accuracy and applicability (R2 = 1 and RMSE = 0.0018714) which is more accurate than previous models presented by former researchers. Among various factors of the sensitivity analysis, temperature and pressure had the greatest effect on the output values, so that the output parameter has a direct relationship with temperature and an inverse relationship with pressure with relevancy factors of 22.44% and −79.81%.

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Crowding effects on the temperature and pressure dependent structure, stability and folding kinetics of Staphylococcal Nuclease

Physical Chemistry Chemical Physics ◽

10.1039/c3cp55040k ◽

2014 ◽

Vol 16 (13) ◽

pp. 5965 ◽

Cited By ~ 34

Author(s):

M. Erlkamp ◽

S. Grobelny ◽

R. Winter

Keyword(s):

Staphylococcal Nuclease ◽

Structure Stability ◽

Folding Kinetics ◽

Crowding Effects ◽

Temperature And Pressure ◽

Kinetics Of

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Calculation of the thermodynamic functions from the Raman frequency shifts close to the 𝜀–δloc–δ transitions and Pippard relations in nitrogen

Modern Physics Letters B ◽

10.1142/s0217984920503820 ◽

2020 ◽

Vol 34 (33) ◽

pp. 2050382 ◽

Cited By ~ 1

Author(s):

O. Akay ◽

H. Yurtseven

Keyword(s):

Thermodynamic Functions ◽

Isothermal Compressibility ◽

Raman Frequency ◽

Molecular Solids ◽

Expansion Formula ◽

Text Data ◽

Frequency Shifts ◽

Solid Nitrogen ◽

Temperature And Pressure ◽

The Difference

Thermodynamic functions of the thermal expansion [Formula: see text], isothermal compressibility [Formula: see text] and the difference in the heat capacity [Formula: see text] are calculated as a function of temperature ([Formula: see text] GPa) close to the transitions of [Formula: see text][Formula: see text]–[Formula: see text][Formula: see text] and [Formula: see text][Formula: see text]–[Formula: see text][Formula: see text] in the solid nitrogen. This calculation is performed by using the observed Raman frequency shifts of vibrons [Formula: see text] and [Formula: see text]. Also, by using the observed [Formula: see text]–[Formula: see text] data, those thermodynamic functions are predicted at various pressures for the fluid–solid transition in nitrogen. For both calculations, observed data are used from the literature. From the temperature and pressure dependences of the thermodynamic functions studied, the Pippard relations are examined close to the [Formula: see text][Formula: see text]–[Formula: see text][Formula: see text][Formula: see text]–[Formula: see text][Formula: see text] transitions and also fluid–solid transition in nitrogen.We find that the thermodynamic functions can be predicted from the Raman frequency shifts and that the Pippard relations can be established for both the [Formula: see text][Formula: see text]–[Formula: see text][Formula: see text][Formula: see text]–[Formula: see text][Formula: see text] and fluid–solid transitions in nitrogen. This method of predicting the thermodynamic functions can also be applied to some other molecular solids.

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CALCULATION OF VOLUME AS FUNCTIONS OF TEMPERATURE AND PRESSURE IN ICE I CLOSE TO THE MELTING POINT

International Journal of Modern Physics B ◽

10.1142/s0217979210056293 ◽

2010 ◽

Vol 24 (19) ◽

pp. 3749-3758

Author(s):

E. KILIT ◽

H. YURTSEVEN

Keyword(s):

Experimental Data ◽

Melting Point ◽

Temperature Dependence ◽

Pressure Dependence ◽

Critical Behavior ◽

Isothermal Compressibility ◽

Thermal Expansivity ◽

Experimental Measurements ◽

Approximate Relation ◽

Temperature And Pressure

We calculate in this study the volume of ice I as functions of temperature and pressure close to the melting point by analyzing the experimental data for the thermal expansivity. Using an approximate relation, the temperature dependence of the volume is calculated at 202.4 MPa from the thermal expansivity of ice I. The pressure dependence of the volume is also calculated at 252.3 K from the isothermal compressibility of ice I close to the melting point. The volume calculated here as functions of temperature and pressure shows critical behavior close to the melting point in ice I, which can be tested by the experimental measurements.

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Direct Measurement of the Thermal Pressure Coefficient of Water

Australian Journal of Chemistry ◽

10.1071/ch9620740 ◽

1962 ◽

Vol 15 (4) ◽

pp. 740 ◽

Cited By ~ 1

Author(s):

GN Malcolm ◽

GLD Ritchie

Keyword(s):

Thermal Expansion ◽

Satisfactory Agreement ◽

Direct Measurement ◽

Isothermal Compressibility ◽

Pressure Coefficient ◽

Constant Volume ◽

Thermal Pressure ◽

Wide Range ◽

Temperature And Pressure

A constant volume thermometer has been used to measure the thermal pressure coefficient of water over a wide range of temperature and pressure. The results show satisfactory agreement with values calculated from the appropriate data for the coefficients of thermal expansion and isothermal compressibility of water.

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Modeling of density and calculations of derived volumetric properties for n-hexane, toluene and dichloromethane at pressures 0.1-60 MPa and temperatures 288.15-413.15 K

Journal of the Serbian Chemical Society ◽

10.2298/jsc150318062i ◽

2015 ◽

Vol 80 (11) ◽

pp. 1423-1433 ◽

Cited By ~ 9

Author(s):

Gorica Ivanis ◽

Aleksandar Tasic ◽

Ivona Radovic ◽

Bojan Djordjevic ◽

Slobodan Serbanovic ◽

...

Keyword(s):

Isothermal Compressibility ◽

Constant Pressure ◽

Thermal Expansivity ◽

Volumetric Properties ◽

Density Data ◽

Tait Equation Of State ◽

Derived Properties ◽

Temperature And Pressure ◽

The Difference ◽

Isobaric Thermal Expansivity

Densities data of n-hexane, toluene and dichloromethane at temperatures 288.15-413.15 K and at pressures 0.1-60 MPa, determined in our previous work, were fitted to the modified Tait equation of state. The fitted temperature-pressure dependent density data were used to calculate the derived properties: the isothermal compressibility, the isobaric thermal expansivity, the difference between specific heat capacity at constant pressure and at constant volume and the internal pressure, over the entire temperature and pressure intervals specified above. In order to assess the proposed modeling procedure, a comparison of the obtained values for the isothermal compressibility and the isobaric thermal expansivity with the corresponding literature data were performed. The average absolute percentage deviations for isothermal compressibility were: for n-hexane 2.01-3.64%, for toluene 0.64-2.48% and for dichloromethane 1.81-3.20%; for the isobaric thermal expansivity: for n-hexane 1.31-4.17%, for toluene 0.71-2.45% and for dichloromethane 1.16-1.61%. By comparing the obtained deviations values with those found in the literature it can be concluded that the presented results agree good with the literature data.

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