Partial specific heat capacity of benzene and of toluene in aqueous solution determined calorimetrically for a broad temperature range

1988 ◽  
Vol 20 (4) ◽  
pp. 405-412 ◽  
Author(s):  
G.I Makhatadze ◽  
P.L Privalov
Author(s):  
Gaurav Gupta ◽  
Vasim Shaikh ◽  
Sachin Kalas ◽  
Kesharsingh Patil

Aims: To study the specific heat capacity for biologically and medicinally important compounds, namely, lidocaine hydrochloride, clove oil and brta-Piperine using DSC technique. Background: One of the main problems in the science of medicine is the application of drug molecules with limited solubility in water and in biofluids. Solubility is related to chemical potential of the solutes involved which imparts free energy avenues, a necessary requirement for equilibrium processes. The convincing solutions for solving this issue are the utilization of ionic liquids as drug. Lidocaine is the most widely utilized intraoral injected dental anesthetic prior to performing painful medical procedures. Besides that, lidocaine hydrochloride is a salt which is having melting point 76 0C (349 K) and behaves as ionic liquid after melting. Clove oil and β-piperine are very well-known naturally occurring medicinal compounds having broad spectrum of applications. Objective: To study the thermal gravimetry analysis behaviour for lidocaine hydrochloride, clove oil and β-piperine. To compute specific heat capacity at constant pressure, as a function of temperature for the studied systems. Method: In the present communication, the studies of thermal gravimetry analysis (TGA) and differential scanning calorimetry (DSC) for these compounds are described. The data of heat flow have been utilized to obtain specific heat capacity (Cp) values for lidocaine hydrochloride, clove oil and β-piperine over a temperature range in between 75 0C (348 K) and 155 0C (428 K) based upon the methodology we have developed. Result: The data of heat flow have been utilized to obtain specific heat capacity (Cp) values for lidocaine hydrochloride, clove oil and β-piperine over a temperature range in between 75 0C (348 K) and 155 0C (428 K) based upon the methodology we have developed. Conclusion: LC•HCl behaves as an ionic liquid between 76 and 230 0C (349 and 503 K). Clove oil is having lower specific heat capacity values and is similar to other organic aromatic compounds while piperine exhibits comparative high specific heat capacity values indicating possibilities of intramolecular hydrogen bonding which is generally not affected by temperature.


2016 ◽  
Vol 30 (04) ◽  
pp. 1650026 ◽  
Author(s):  
Hüseyin Koç ◽  
Erhan Eser

The aim of this paper is to provide a simple and reliable analytical expression for the thermodynamic properties calculated in terms of the Debye model using the binomial coefficient, and examine specific heat capacity of CdTe in the 300–1400 K temperature range. The obtained results have been compared with the corresponding experimental and theoretical results. The calculated results are in good agreement with the other results over the entire temperature range.


2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Kian Eisazadeh-Far ◽  
Hameed Metghalchi ◽  
James C. Keck

Thermodynamic properties of ionized gases at high temperatures have been calculated by a new model based on local equilibrium conditions. Calculations have been done for nitrogen, oxygen, air, argon, and helium. The temperature range is 300–100,000 K. Thermodynamic properties include specific heat capacity, density, mole fraction of particles, and enthalpy. The model has been developed using statistical thermodynamics methods. Results have been compared with other researchers and the agreement is good.


2008 ◽  
Vol 22 (30) ◽  
pp. 5349-5355 ◽  
Author(s):  
SAVAŞ SÖNMEZOǦLU

The aim of this paper is to provide validity and reliable analytical relation for the thermodynamic functions calculated in terms of the Debye temperature using incomplete gamma functions, and examines the entropy and specific heat capacity of hexagonal single crystals of GaN in the 0–1800 K temperature range. The obtained results have been compared with the corresponding experimental and theoretical results. Our results are in excellent agreement with the theoretical results over the entire temperature range. It has also shown that at low temperature, our results are in very good agreement with the experimental results, however, at high temperature, our results are lower than other experimental results.


Author(s):  
T. A. Kompan ◽  
V. I. Kulagin ◽  
V. V. Vlasova ◽  
S. V. Kondratiev ◽  
N. F. Pukhov

2013 ◽  
Vol 67 (3) ◽  
pp. 495-511
Author(s):  
Branko Pejovic ◽  
Ljubica Vasiljevic ◽  
Vladan Micic ◽  
Mitar Perusic

Starting from the definition of the average specific heat capacity for chosen temperature range, the analytic dependence between the real and the mean specific heat capacities is obtained using differential and integral calculation. The obtained relation in differential form for the defined temperature range allows for the problem to be solved directly, without any special restrictions on its use. Using the obtained relation, a general model in the form of a polynomial of arbitrary degree in the function of temperature was derived, which has more suitable and faster practical application and is more general in character than the existing model. New graphical method for solving the problem is obtained based on differential geometry and using the derived equation. This may also have practical significance since many problems in thermodynamics are solved analytically and graphically. This result was used in order to obtain the amount of specific heat exchanged using an analytical model or a planimetric method. In addition, this graphical solution was used for the construction of the diagram showing the dependence between the specific heat exchanged and temperature. This diagram also gives a simple graphical procedure for the calculation of the real and the average specific heat capacity for arbitrary temperature or temperature interval. The confirmation for all graphic constructions is obtained using the differential properties between thermodynamic units. In order for the graphical solutions presented to be applicable in practice, suitable ratio coefficients have been determined for all cases. Verification of the model presented, as well as the possibilities of its application, were given using several characteristic examples of semi-ideal and real gas. Apart from linear and non-linear functions in the form of polynomials, the exponential function of the dependence between specific heat capacities and temperature was also analysed in this process.


2021 ◽  
pp. 29-32
Author(s):  
Tatiana A. Kompan ◽  
Valentin I. Kulagin ◽  
Viktoriya V. Vlasova ◽  
Sergey V. Kondratiev ◽  
Nikolay F. Pukhov

The possibility of using beryllium as a means of storing and transferring a unit of specific heat capacity and extending the range of values of heat capacity measures from 1654 to 2900 J/(kg·K) towards the upper limit is estimated. The temperature dependence of the specific heat capacity of beryllium samples of known composition in the temperature range of 260–870 K has been determined. The reproducibility of the thermophysical properties of beryllium over time and under repeated heating in the specified temperature range is analyzed. The results obtained are relevant for the field of metrological support in the field of measurements of thermophysical quantities.


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