scholarly journals Temperature dependence of the specific heat and thermodynamic functions AК1М2 alloy, doped strontium

2019 ◽  
Vol 21 (1) ◽  
pp. 35-42 ◽  
Author(s):  
I. N. Ganiev ◽  
S. E. Otajonov ◽  
N. F. Ibrohimov ◽  
M. Mahmudov
Keyword(s):  
Heat Capacity ◽  
Gibbs Energy ◽  
Specific Heat ◽  
Temperature Dependence ◽  
Specific Heat Capacity ◽  
Thermodynamic Functions ◽  
Inverse Relationship ◽  
Alloying Element ◽  
Enthalpy And Entropy ◽  
Increasing Temperature

In the heat «cooling» investigated the temperature dependence of the specific heat capacity and thermodynamic functions doped strontium alloy AK1М2 in the range 298,15—900 K. Mathematical models are obtained that describe the change in these properties of alloys in the temperature range 298.15—900 K, as well as on the concentration of the doping component. It was found that with increasing temperature, specific heat capacity, enthalpy and entropy alloys increase, and the concentration up to 0.5 wt.% of the alloying element decreases. Gibbs energy values have an inverse relationship, i.e., temperature — decreases the content of alloying component — is up to 0.5 wt.% growing.

scholarly journals Temperature dependence of the heat capacity and change in the thermodynamic functions of strontium-alloyed AK1M2 alloy

2018 ◽  
Vol 4 (3) ◽  
pp. 119-124
Author(s):  
Izatullo N. Ganiev ◽  
Suhrob E. Otajonov ◽  
Nasim F. Ibrohimov ◽  
M. Mahmudov
Keyword(s):  
Heat Capacity ◽  
Gibbs Energy ◽  
Mathematical Models ◽  
Specific Heat ◽  
Temperature Dependence ◽  
Thermodynamic Functions ◽  
Temperature Decrease ◽  
Cooling Mode ◽  
Enthalpy And Entropy ◽  
Aluminum Base

The temperature dependence of the specific heat capacity and change in the thermodynamic functions of strontium-alloyed ultrahigh-purity aluminum base AK1M2 alloy have been studied in “cooling” mode over the 298.15–900 K range. Mathematical models describing the evolution of these properties of the alloys in the abovementioned temperature range with change in alloying addition concentration have been obtained. The heat capacity, enthalpy and entropy of the alloys increase with temperature, decrease with an increase in the alloying addition concentration to 0.5 wt.% and grow with a further increase in the alloying addition concentration. The Gibbs energy of the alloys has an inverse dependence: it decreases with an increase in temperature and grows with an increase in the alloying addition concentration to 0.5 wt.%.

Size and temperature dependence of the specific heat capacity of carbon nanotubes

2006 ◽  
Vol 600 (18) ◽  
pp. 3633-3636 ◽  
Author(s):  
S.P. Hepplestone ◽  
A.M. Ciavarella ◽  
C. Janke ◽  
G.P. Srivastava
Keyword(s):  
Carbon Nanotubes ◽  
Heat Capacity ◽  
Specific Heat ◽  
Temperature Dependence ◽  
Specific Heat Capacity

scholarly journals Effect of alkaline earth metals on the heat capacity and change of thermodynamic function of AK1M2 alloy on the basis of specific aluminum

2020 ◽  
Vol 23 (3) ◽  
pp. 222-228
Author(s):  
I. N. Ganiev ◽  
S. E. Otajonov ◽  
M. Mahmudov ◽  
M. M. Mahmadizida ◽  
V. D. Abulkhaev
Keyword(s):  
Heat Capacity ◽  
Gibbs Energy ◽  
Temperature Dependence ◽  
Alkaline Earth ◽  
Reference Sample ◽  
Alkaline Earth Metals ◽  
Model Alloy ◽  
Cooling Mode ◽  
Cooling Rates ◽  
Enthalpy And Entropy

It is known that high purity aluminum with a minimum content of impurities is widely used in electronic technology for the manufacture of conductive paths in integrated circuits. Hence the development of new compositions of alloys based on such a metal is a very urgent task. One of the promising alloys based on such a metal is alloy AK1M2 (Al + 1 % Si + 2 % Cu). This alloy was accepted by us as a model alloy and subjected to modification by alkaline earth metals.Heat capacity is the most important characteristic of substances and by its variation with temperature one can determine the type of phase transformation, the Debye temperature, the energy of formation of vacancies, the coefficient of electronic heat capacity, and other properties. In the present work, the heat capacity of the AK1M2 alloy with alkaline earth metals was determined in the “cooling” mode from the known heat capacity of a reference sample from copper. For which, by processing the curves of the cooling rate of samples from the alloy AK1M2 with alkaline earth metals and the standard, polynomials were obtained which describe their cooling rates. Further, by experimentally found values of the cooling rates of the standard and samples from alloys, knowing their masses, the polynomials of the temperature dependence of the heat capacity of the alloys and the standard were established, which are described by a four-term equation. Using the integrals of the specific heat, the models of temperature dependence of the change in enthalpy, entropy and Gibbs energy were established.The dependences obtained show that with an increase in temperature, the heat capacity, enthalpy, and entropy of alloys increase, and the values of Gibbs energy decrease. At the same time, additives of alkaline earth metals do not significantly reduce the heat capacity, enthalpy and entropy of the original alloy AK1M2 and increase the value of Gibbs energy. During the transition from alloys with calcium with barium, the heat capacity of the alloys decreases, which correlates with the heat capacity of pure alkaline earth metals within the subgroup.

Thermal Properties of Polyurethane Shape Memory Polymer Filled With Magnetite Particles

2011 ◽  
Author(s):  
Bernd Weidenfeller ◽  
Mathias Anhalt ◽  
Hauke Marquardt ◽  
Frank R. Schilling ◽  
Muhammad Y. Razzaq ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Diffusivity ◽  
Specific Heat ◽  
Shape Memory ◽  
Specific Heat Capacity ◽  
Shape Memory Polymer ◽  
Particle Sizes ◽  
Magnetite Particles ◽  
Increasing Temperature

Temperature dependent thermal diffusivity (295K ≤ T ≤ 375K), specific heat capacity (290K ≤ T ≤ 380K) and thermal conductivity (300K ≤ T ≤ 340K) were measured on extrusion compounded and injection molded polyurethane shape memory polymers filled with different volume fractions (0%, 10%, 20%, 30%, 40%) of magnetite particles (10μm, 50μm and 150μm). With increasing particle content thermal diffusivity arises from α(PU + 0% Fe3O4) ≈ 0.13mm2/s to α(PU + 40% Fe3O4) ≈ 0.31mm2/s whereas d = 10μm particle sizes lead to higher values than larger particle sizes. Values measured for 150μm large particles are lying between values of composites with 10μm and 50μm particle sizes in the whole investigated temperature range. For higher filler contents differences in thermal diffusivity between composites of different particle sizes disappear. Thermal diffusivity decreases with increasing temperature, while thermal conductivity is increasing from λ(PU+0% Fe3O4) ≈ 0.2W/mK to λ(PU+40% Fe3O4) ≈ 0.6W/mK. Corresponding to glass transition temperatures of the polymer, the specific heat capacity shows a rise between 300K and 320K and a decrease between 350K and 370K.

scholarly journals The Important Thermal Characteristics of Matter and Their Computations with the Use of the Gibbs Potentials

2019 ◽  
Vol 19 (2) ◽  
pp. 134-138
Author(s):  
Y. S. Budzhak ◽  
T. Wacławski
Keyword(s):  
Heat Capacity ◽  
Free Energy ◽  
Specific Heat ◽  
Internal Energy ◽  
Gibbs Free Energy ◽  
Specific Heat Capacity ◽  
Thermodynamic Functions ◽  
Thermodynamic Potential ◽  
Thermal Characteristics ◽  
Dynamic Potential

In this paper, the important thermal characteristics of matter  (they describe thermodynamic systems in a state of thermodynamic equilibrium) were calculated.  There are the following  important thermodynamic functions:   the system   internal energy ,  the thermal function (or enthalpy)   the  free  Helmholtz energy, the thermo-dynamic potential  (or Gibbs free energy), the Gibbs grand thermodynamic potential , the entropy ,  the specific heat capacity . These functions are explicit functions of system’s parameters, they fulfil some mathe-matical relationships  and posses   some total differentials. These  functions  are calculated  in this paper and their physical sense is given in the cited works.

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