Thermodynamics of the d-wave pairing in organic superconductors

2016 ◽  
Vol 30 (13) ◽  
pp. 1642020
Author(s):  
S. Kruchinin ◽  
A. Zolotovsky ◽  
S. Yamashita ◽  
Y. Nakazawa
Keyword(s):  
Heat Capacity ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Theoretical Calculations ◽  
Organic Superconductors ◽  
Text Type ◽  
Wave Pairing ◽  
Organic Complexes ◽  
D Wave ◽  
Good Agreement

Organic superconductors with [Formula: see text]-type structure are most frequently identified as nodal gap superconductors from the experimental observation of a power-law behavior in the low-temperature thermodynamic properties such as specific heat capacity. We perform series of theoretical calculations of specific heat capacity of three typical organic complexes with different transition temperatures by using Bogolyubov–de Gennes equations. The good agreement between the experimental data and the calculations demonstrates that the [Formula: see text]-wave pairing is certainly realized in these superconductors.

Estimation of the heat capacity of CdTe semiconductor

2016 ◽  
Vol 30 (04) ◽  
pp. 1650026 ◽  
Author(s):  
Hüseyin Koç ◽  
Erhan Eser
Keyword(s):  
Heat Capacity ◽  
Thermodynamic Properties ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Binomial Coefficient ◽  
Debye Model ◽  
The Other ◽  
Temperature Range ◽  
Theoretical Results ◽  
Good Agreement

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.

INVESTIGATION OF THE ENTROPY AND SPECIFIC HEAT CAPACITY OF GaN USING INCOMPLETE GAMMA FUNCTIONS

2008 ◽  
Vol 22 (30) ◽  
pp. 5349-5355 ◽  
Author(s):  
SAVAŞ SÖNMEZOǦLU
Keyword(s):  
Heat Capacity ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Experimental Results ◽  
Analytical Relation ◽  
Gamma Functions ◽  
Temperature Range ◽  
Incomplete Gamma Functions ◽  
Theoretical Results ◽  
Good Agreement

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.

Теплофизические характеристики теплозащитного материала корпуса ракетного двигателя при температурах до 1000 оС

2021 ◽  
pp. 11-18
Author(s):  
Геннадий Александрович Фролов ◽  
Юрий Игоревич Евдокименко ◽  
Вячеслав Михайлович Кисель ◽  
Ирина Александровна Гусарова
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Temperature Fields ◽  
Thermophysical Characteristics ◽  
Furnace Heating ◽  
Temperature Dependences ◽  
Good Agreement

An experimental determination of the temperature dependences of the specific heat capacity and the thermal conductivity coefficient of the multifunctional coating MFP-92 at temperatures up to 1000 °C has been carried out. At temperatures up to 450 °C, an IT-c-400 device was used to determine the specific heat capacity. IT-l-400 device was used for the determination of thermal conductivity. At higher temperatures, the determination of the thermophysical characteristics (TPC) was carried out by solving the inverse problem of thermal conductivity (IPT) in a flat plate under conditions of one-sided heating in a muffle furnace. Composite material MFP-92 is a multilayer structure with upper layers based on silica fabric and chromophosphate binder and lower layers based on mullite-silica fabric and aluminosilicate binder. The TPC of the layers also differ from each other, and, accordingly, the properties of this material as a whole can be determined only in the form of their effective values, averaged in one way or another over the thickness of the coating. In addition, during heating, the material undergoes significant physicochemical transformations associated with the thermal destruction of its components, manifested in the form of abundant gas release, and a decrease in the density of the material, which significantly changes its TPC and determines its dependence on the heating rate. Therefore, studies of the thermophysical characteristics of the MFP-92 material were carried out with several (2-5) consecutive heating cycles. It was found that in four heating cycles of the MFP-92 material up to 450 °C for 75 minutes when measuring the specific heat on the IT-c-400 device, its temperature dependence significantly changes qualitatively and quantitatively. With furnace heating to 1000 °C, the temperature dependences of the TPC of the material, determined in the first and second heating cycles, have a different form, but change insignificantly in subsequent heating cycles. This makes it possible to ascribe to the MFP-92 material a set of two sets of TPC related to its initial (phase A) and annealed after heating to 1000 °C (phase B) states. Using the obtained TPС of phase A (including the magnitude of the thermal effect of irreversible endothermic phase transition at 100 °C) and phase B, good agreement was obtained between the calculated and experimental temperature fields in the samples under furnace heating conditions.

Experimental Study on the Specific Heat Capacity Measurement of Water-Based Al2O3-Cu Hybrid Nanofluid by using Differential Thermal Analysis Method

2019 ◽  
Vol 15 ◽  
Author(s):  
Andaç Batur Çolak ◽  
Oğuzhan Yıldız ◽  
Mustafa Bayrak ◽  
Ali Celen ◽  
Ahmet Selim Dalkılıç ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Thermophysical Properties ◽  
Volume Concentration ◽  
Pure Water ◽  
Heat Capacity Measurement ◽  
Experimental Results ◽  
Hybrid Nanofluid ◽  
Capacity Measurement

Background: Researchers working in the field of nanofluid have done many studies on the thermophysical properties of nanofluids. Among these studies, the number of studies on specific heat are rather limited. In the study of the heat transfer performance of nanofluids, it is necessary to increase the number of specific heat studies, whose subject is one of the important thermophysical properties. Objective: The authors aimed to measure the specific heat values of Al2O3/water, Cu/water nanofluids and Al2O3-Cu/water hybrid nanofluids using the DTA method, and compare the results with those frequently used in the literature. In addition, this study focuses on the effect of temperature and volume concentration on specific heat. Method: The two-step method was used in the preparation of nanofluids. The pure water selected as the base fluid was mixed with the Al2O3 and Cu nanoparticles and Arabic Gum as the surfactant, firstly mixed in the magnetic stirrer for half an hour. It was then homogenized for 6 hours in the ultrasonic homogenizer. Results: After the experiments, the specific heat of nanofluids and hybrid nanofluid were compared and the temperature and volume concentration of specific heat were investigated. Then, the experimental results obtained for all three fluids were compared with the two frequently used correlations in the literature. Conclusion: Specific heat capacity increased with increasing temperature, and decreased with increasing volume concentration for three tested nanofluids. Cu/water has the lowest specific heat capacity among all tested fluids. Experimental specific heat capacity measurement results are compared by using the models developed by Pak and Cho and Xuan and Roetzel. According to experimental results, these correlations can predict experimental results within the range of ±1%.

Development of the room temperature protocol based on room temperature ionic liquids and surfactant ionic liquids for the synthesis of derivatives of 2-amino-thiazoles and thermo-physical analysis of the synthesized derivatives using TGA-DSC.

2020 ◽  
Vol 10 ◽  
Author(s):  
Chandrakant Sarode ◽  
Sachin Yeole ◽  
Ganesh Chaudhari ◽  
Govinda Waghulde ◽  
Gaurav Gupta
Keyword(s):  
Thermal Analysis ◽  
Heat Capacity ◽  
Ionic Liquids ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Room Temperature ◽  
Heat Capacity Data ◽  
General Strategy ◽  
Capacity Data ◽  
Derivatives Of

Aims: To develop an efficient protocol, which involves an elegant exploration of the catalytic potential of both the room temperature and surfactant ionic liquids towards the synthesis of biologically important derivatives of 2-aminothiazole. Objective: Specific heat capacity data as a function of temperature for the synthesized 2- aminothiazole derivatives has been advanced by exploring their thermal profiles. Method: The thermal gravimetry analysis and differential scanning calorimetry techniques are used systematically. Results: The present strategy could prove to be a useful general strategy for researchers working in the field of surfactants and surfactant based ionic liquids towards their exploration in organic synthesis. In addition to that, effect of electronic parameters on the melting temperature of the corresponding 2-aminothiazole has been demonstrated with the help of thermal analysis. Specific heat capacity data as a function of temperature for the synthesized 2-aminothiazole derivatives has also been reported. Conclusion: Melting behavior of the synthesized 2-aminothiazole derivatives is to be described on the basis of electronic effects with the help of thermal analysis. Additionally, the specific heat capacity data can be helpful to the chemists, those are engaged in chemical modelling as well as docking studies. Furthermore, the data also helps to determine valuable thermodynamic parameters such as entropy and enthalpy.

scholarly journals Influence of alkaline modification on selected properties of banana fiber paperbricks

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abayomi A. Akinwande ◽  
Adeolu A. Adediran ◽  
Oluwatosin A. Balogun ◽  
Oluwaseyi S. Olusoju ◽  
Olanrewaju S. Adesina
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Moisture Absorption ◽  
Water Volume ◽  
Banana Fiber ◽  
Fiber Loading ◽  
Banana Fibers ◽  
Alkaline Modification

AbstractIn a bid to develop paper bricks as alternative masonry units, unmodified banana fibers (UMBF) and alkaline (1 Molar aqueous sodium hydroxide) modified banana fibers (AMBF), fine sand, and ordinary Portland cement were blended with waste paper pulp. The fibers were introduced in varying proportions of 0, 0.5, 1.0 1.5, 2.0, and 2.5 wt% (by weight of the pulp) and curing was done for 28 and 56 days. Properties such as water and moisture absorption, compressive, flexural, and splitting tensile strengths, thermal conductivity, and specific heat capacity were appraised. The outcome of the examinations carried out revealed that water absorption rose with fiber loading while AMBF reinforced samples absorbed lesser water volume than UMBF reinforced samples; a feat occasioned by alkaline treatment of banana fiber. Moisture absorption increased with paper bricks doped with UMBF, while in the case of AMBF-paper bricks, property value was noted to depreciate with increment in AMBF proportion. Fiber loading resulted in improvement of compressive, flexural, and splitting tensile strengths and it was noted that AMBF reinforced samples performed better. The result of the thermal test showed that incorporation of UMBF led to depreciation in thermal conductivity while AMBF infusion in the bricks initiated increment in value. Opposite behaviour was observed for specific heat capacity as UMBF enhanced heat capacity while AMBF led to depreciation. Experimental trend analysis carried out indicates that curing length and alkaline modification of fiber were effective in maximizing the properties of paperbricks for masonry construction.

scholarly journals Effects of SiO2 Nanoparticle Dispersion on The Heat Storage Property of the Solar Salt for Solar Power Applications

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 703
Author(s):  
Zhao Li ◽  
Liu Cui ◽  
Baorang Li ◽  
Xiaoze Du
Keyword(s):  
Heat Capacity ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Heat Storage ◽  
Md Simulations ◽  
Interfacial Thermal Resistance ◽  
Solar Salt ◽  
Salt Ions ◽  
Base Salt ◽  
Storage Property

The effects of SiO2 nanoparticles on the heat storage properties of Solar Salt (NaNO3-KNO3) are studied using experimental and molecular dynamics (MD) simulations. The experiment results show the specific heat capacity of the molten salt-based nanofluids is higher than that of the pure base salt. We focus on the inference regarding the possible mechanisms behind the enhancement of the specific heat capacity which are considered more acceptable by the majority of researchers, the energy and force in the system are analyzed by MD simulations. The results demonstrate that the higher specific heat capacity of the nanoparticle is not the reason leading to the heat storage enhancement. Additionally, the analysis of potential energy and system configuration shows that the other possible mechanisms (i.e., interfacial thermal resistance theory and compressed layer theory) are only superficial. The forces between the nanoparticle atoms and base salt ions construct the constraint of the base salt ions, further forms the interfacial thermal resistance, and the compressed layer around the nanoparticle. This constraint has a more stable state and requires more energy to deform it, leading to the improvement of the heat storage property of nanofluids. Our findings uncover the mechanisms of specific heat capacity enhancement and guide the preparation of molten salt-based nanofluids.

A critical review of specific heat capacity of hybrid nanofluids for thermal energy applications

2021 ◽  
pp. 116890
Author(s):  
Humphrey Adun ◽  
Ifeoluwa Wole-Osho ◽  
Eric C. Okonkwo ◽  
Doga Kavaz ◽  
Mustafa Dagbasi
Keyword(s):  
Heat Capacity ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Thermal Energy ◽  
Critical Review ◽  
Energy Applications ◽  
Hybrid Nanofluids

scholarly journals A simple model for predicting soil temperature in snow-covered and seasonally frozen soil: model description and testing

2004 ◽  
Vol 8 (4) ◽  
pp. 706-716 ◽  
Author(s):  
K. Rankinen ◽  
T. Karvonen ◽  
D. Butterfield
Keyword(s):  
Heat Capacity ◽  
Simple Model ◽  
Soil Temperature ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Frozen Soil ◽  
Model Description ◽  
Freezing And Thawing ◽  
Catchment Scale ◽  
Soil Temperatures

Abstract. Microbial processes in soil are moisture, nutrient and temperature dependent and, consequently, accurate calculation of soil temperature is important for modelling nitrogen processes. Microbial activity in soil occurs even at sub-zero temperatures so that, in northern latitudes, a method to calculate soil temperature under snow cover and in frozen soils is required. This paper describes a new and simple model to calculate daily values for soil temperature at various depths in both frozen and unfrozen soils. The model requires four parameters: average soil thermal conductivity, specific heat capacity of soil, specific heat capacity due to freezing and thawing and an empirical snow parameter. Precipitation, air temperature and snow depth (measured or calculated) are needed as input variables. The proposed model was applied to five sites in different parts of Finland representing different climates and soil types. Observed soil temperatures at depths of 20 and 50 cm (September 1981–August 1990) were used for model calibration. The calibrated model was then tested using observed soil temperatures from September 1990 to August 2001. R2-values of the calibration period varied between 0.87 and 0.96 at a depth of 20 cm and between 0.78 and 0.97 at 50 cm. R2-values of the testing period were between 0.87 and 0.94 at a depth of 20cm, and between 0.80 and 0.98 at 50cm. Thus, despite the simplifications made, the model was able to simulate soil temperature at these study sites. This simple model simulates soil temperature well in the uppermost soil layers where most of the nitrogen processes occur. The small number of parameters required means that the model is suitable for addition to catchment scale models. Keywords: soil temperature, snow model

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