Decrease In Specific Heat Research Articles

Coconut shell-derived activated carbon-enhanced water phase change material for cold thermal energy storage.

In building cooling, the demand for cooling surges during specific times, stressing air-conditioner operation, and additional cooling is often wasted during low-demand periods. Water-phase change material (W-PCM)-based thermal energy storage (TES) allows for load shifting and effective management of peak demand by storing cooling energy when the demand is low. This stored energy can be deployed during peak hours, decreasing energy usage and associated CO2 emissions. However, the use of W-PCMs was hindered by phase separation, slow energy transfer, and high supercooling degree (SCD). We synthesized coconut shell (CNS)-produced activated carbon (ACC) to use as a thermal enhancer in W-PCMs for the first time. First, ACC was synthesized from CNS via steam activation. Then, transmission electron microscopy was used to confirm the pore morphology of the CNS-ACC.The synthesis of the W-PCM with various weight percentages (0.1, 0.6, and 1.2) of CNS-ACC was accomplished in two steps. Zeta potential distribution analysis revealed that the W-PCM with CNS-ACC exhibited colloidal stability. Thermal conductivity (TC) and thermogram analyses revealed that a dose of 1.2 wt% CNS-ACC enhanced liquid and solid TC by 9% and 22%, respectively, despite a 6% and 8% decrease in specific heat and latent heat. More specifically, solidification assessment in a spherical enclosure revealed 100% suppression of SCD with 1.2 wt% CNS-ACC. As a result of this and the enhanced TC, the overall solidification process was accelerated, reducing the overall duration by 18.5%. Thus, the combination of CNS-derived ACC and W-PCM for TES in building cooling could reduce energy consumption and associated CO2 emissions.

Numerical study of the volume fraction and thermophysical properties of nanofluids in a porous medium

PurposeThe purpose of the paper is to conduct a numerical and experimental investigation into the properties of nanofluids containing spherical nanoparticles of random sizes flowing through a porous medium. The study aims to understand how the thermophysical properties of the nanofluid are affected by factors such as nanoparticle volume fraction, permeability of the porous medium, and pore size. The paper provides insights into the behavior of nanofluids in complex environments and explores the impact of varying conditions on key properties such as thermal conductivity, density, viscosity, and specific heat. Ultimately, the research contributes to the broader understanding of nanofluid dynamics and has potential implications for engineering and industrial applications in porous media.Design/methodology/approachThis paper investigates nanofluids with spherical nanoparticles in a porous medium, exploring thermal conductivity, density, specific heat, and dynamic viscosity. Studying three compositions, the analysis employs the classical Maxwell model and Koo and Kleinstreuer’s approach for thermal conductivity, considering particle shape and temperature effects. Density and specific heat are defined based on mass and volume ratios. Dynamic viscosity models, including Brinkman’s and Gherasim et al.'s, are discussed. Numerical simulations, implemented in Python using the Langevin model, yield results processed in Origin Pro. This research enhances understanding of nanofluid behavior, contributing valuable insights to porous media applications.FindingsThis study involves a numerical examination of nanofluid properties, featuring spherical nanoparticles of varying sizes suspended in a base fluid with known density, flowing through a porous medium. Experimental findings reveal a notable increase in thermal conductivity, density, and viscosity as the volume fraction of particles rises. Conversely, specific heat experiences a decrease with higher particle volume concentration.xD; xA; The influence of permeability and pore size on particle volume fraction variation is a key focus. Interestingly, while the permeability of the medium has a significant effect, it is observed that it increases with permeability. This underscores the role of the medium’s nature in altering the thermophysical properties of nanofluids.Originality/valueThis paper presents a novel numerical study on nanofluids with randomly sized spherical nanoparticles flowing in a porous medium. It explores the impact of porous medium properties on nanofluid thermophysical characteristics, emphasizing the significance of permeability and pore size. The inclusion of random nanoparticle sizes adds practical relevance. Contrasting trends are observed, where thermal conductivity, density, and viscosity increase with particle volume fraction, while specific heat decreases. These findings offer valuable insights for engineering applications, providing a deeper understanding of nanofluid behavior in porous environments and guiding the design of efficient systems in various industrial contexts.

Thermophysical Properties of SWCNT Nanofluid

AbstractThe current paper has the objective of exploring the thermophysical properties (TPPs) of single walled carbon nanotube (SWCNT) nanofluids (NFs) for heat transfer applications. The effect of dispersing the nanotubes in conventional heat transfer fluids (HTFs) has been investigated. Carbon nanotubes (CNTs) have exceptionally high thermal conductivities. Using the effective medium theory, density, specific heat, thermal conductivity, and viscosity has been evaluated as functions of volume fractions. The base fluids considered in this work are water, ethylene glycol, engine oil, and kerosene oil as these are the commonly used HTFs for industrial applications. Theoretical predictions from this study show an increase in density, thermal conductivity, and viscosity with volume fraction while there is a decrease in specific heat with volume fraction. The effect of the aspect ratio (AR) of CNTs on the thermal conductivity of NF is also investigated. For low volume fractions of SWCNT, the thermal conductivity has been found to increase with AR. Further, this study has been extended for a real‐world application of heat transfer using SWCNT. In this paper, a numerical investigation of heat transfer in a square enclosure with differentially heated vertical walls, filled with SWCNT‐water NF under natural convection is carried out. Due to low concentrations of SWCNT in water, single phase flow is assumed. Velocity and temperature distributions are obtained as solutions to the energy and Navier–Stoke's equations. A comparison of the temperature and velocity profile has been represented by simulating the system over a range of Rayleigh numbers.

PERFORMANCE IMPROVEMENT OF CIRCULAR PARABOLIC CONCENTRATING SOLAR COOKER USING NANO-MIXED BINARY SALT PHASE CHANGE MATERIAL

A multi-objective investigation has been carried out for a parabolic concentrator-type solar cooker with the use of nano-mixed binary salts phase change material (PCM) materials. Binary salts like NaNO<sub>3</sub> and KNO<sub>3</sub> are mixed with alumina (Al<sub>2</sub>O<sub>3</sub>) nanoparticles in the ratio of 0.5%, 1%, and 1.5% by weight. Properties such as thermal conductivity, specific heat, melting point, and thermal diffusivity are computed experimentally. Two food items, namely rice and dal, are selected for cooking purposes. The experimental results obtained from this research work show some promising returns. As compared to the plain PCM, the nano-mixed PCM reduces the cooking time, and with an increase in the addition of nanoparticles in PCM, the overall cooking time for both food items decreases. A difference of 5-6 minutes has been observed between plain PCM and nano-mixed PCM cooking. Another important observation made during this study is that the thermal properties of PCM material are affected by the addition of nanoparticles. The thermal conductivity increases by almost 10% and thermal diffusivity increases by 20%. The melting point of PCM decreases by 22°C, and the specific heat decreases by 12% and 17% at a temperature of 100°C and 250°C, respectively. Finally, it is concluded that the use of alumina nanoparticles in the binary salts PCM improves the thermal storage capacity of the PCM material.

Spin gap in quasi-one-dimensional S = 3/2 antiferromagnet CoTi2O5

Quasi-one-dimensional (1D) antiferromagnets are known to display intriguing phenomena especially when there is a spin gap in their spin-excitation spectra. Here we demonstrate that a spin gap exists in the quasi-1D Heisenberg antiferromagnet CoTi2O5 with highly ordered Co2+/Ti4+ occupation, in which the Co2+ ions with S = 3/2 form a 1D spin chain along the a-axis. CoTi2O5 undergoes an antiferromagnetic transition at T N ∼ 24 K and exhibits obvious anisotropic magnetic susceptibility even in the paramagnetic region. Although a gapless magnetic ground state is usually expected in a quasi-1D Heisenberg antiferromagnet with half-integer spins, by analyzing the specific heat, the thermal conductivity, and the spin-lattice relaxation rate (1/T 1) as a function of temperature, we found that a spin gap is opened in the spin-excitation spectrum of CoTi2O5 around T N, manifested by the rapid decrease of magnetic specific heat to zero, the double-peak characteristic in thermal conductivity, and the exponential decay of 1/T 1 below T N. Both the magnetic measurements and the first-principles calculations results indicate that there is spin-orbit coupling in CoTi2O5, which induces the magnetic anisotropy in CoTi2O5, and then opens the spin gap at low temperature.

Thermophysical properties of Cordyceps militaris change during the freezing process

This study focuses on determining the thermophysical parameters of Cordyceps militaris in the freezing stage of the freeze-drying process. When the temperature of Cordyceps militaris changed from an ambient temperature of 25°C to a freezing temperature of -45°C, the thermophysical parameters of Cordyceps militaris changed much. The study determined the initial freezing point temperature of Cordyceps militaris to be -0.6°C. At temperatures above the initial freezing point, the density (ρ) and specific heat (c) increase slightly as the temperature decreases. In contrast, thermal conductivity (k), thermal diffusivity (a), and enthalpy (h) decrease. However, at temperatures below the initial freezing point, when the temperature decreases, the density, specific heat, and enthalpy decrease while the coefficient of thermal conductivity and thermal diffusion increase. The results obtained from this study can be applied in calculating the heat and mass transfer during the freezing phase in the freeze-drying process of Cordyceps militaris.

Performance Properties of Cement-Glass Composite Bricks (CGCB) with Additively Manufactured (AM) Polymeric Scaffolding.

This study provides an alternative to traditional masonry materials: a cement-glass composite brick (CGCB), with a printed polyethylene terephthalate glycol (PET-G) internal scaffolding (gyroidal structure). This newly designed building material consists of 86% waste (78% glass waste, and 8% recycled PET-G). It can respond to the construction market's needs and provide a cheaper alternative to traditional materials. Performed tests showed an improvement in thermal properties after the use of an internal grate in the brick matrix, i.e., an increase in thermal conductivity (5%), and a decrease in thermal diffusivity (8%) and specific heat (10%). The obtained anisotropy of the CGCB's mechanical properties was much lower than the non-scaffolded parts, indicating a very positive effect of using this type of scaffolding in CGCB bricks.

Effect of Collagen Molecules and Hydroxyapatite Salt on Thermal Properties of Rib, Scapula, and Femur of Some Bovines under Normal and Decalcified Conditions

The study of thermal properties such as conductivity and specific heat of biomaterials is very important as most biological processes, in which biological tissues, cells, and molecules are involved are dependent on body temperature. The main source of body heat is the chemical metabolism of food. Various mechanisms are being adopted by different types of animals to maintain body temperature, such as reducing blood flow through the capillaries nearest the skin surface, body hair can be fluffed up to increase insulation, heat production by shivering, etc. The hard and soft tissues, such as the flesh and bone of animals, play a very important role in keeping the required body temperature. The thermal conductivity and specific heat of the femur, rib, and scapula of two different environment animal ox, the wetland and camel desert dry land are investigated in normal and decalcified conditions. Modified Lee’s apparatus has been used to determine the thermal conductivity, while Renault’s apparatus which is based on the principle of the method of mixtures has been employed for determining the specific heat of samples that were pelletized. A difference in conductivities and specific heat of various bones in both animals was observed due to varied calcium phosphate. The decalcified bone samples of ox and camel show higher thermal conductivity compared to normal bones, while a decrease in specific heat was observed in decalcified bones. The specific heat is affected by the variations in the molecular structure due to changes in temperature. The paper suggests that these techniques are simple, elegant, and inexpensive besides being accurate.

Effects of doping on the thermophysical properties of Ag and Cu doped TiO2 nanoparticles and their nanofluids

A widely accepted method to improve the thermal performance of nanofluids is adding more particles to the fluid, which often causes higher viscosity and sedimentation risk. Therefore, alternative methods are required to create complex structures and improve the properties of particles to acquire similar or even better performance with a smaller amount. Doping is one of the promising methods, and this study examined the effects of doping rates (0.1 and 0.3 %) and materials (Ag and Cu) on the thermophysical properties of ethylene glycol-water-based nanofluids. Nanofluids were prepared with pure and Ag/Cu doped TiO2 nanoparticles at various concentrations (0.3 %, 0.5 %, 1 %, and 2) by mass. The synthesized nanoparticles were characterized by X-ray diffraction (XRD), particle size distribution (PSD), Brunauer, Emmett, and Teller (BET) surface area analysis, and transmission electron microscopy (TEM). Thermophysical property measurements were carried out at a temperature range of 40 and 60 °C. Based on the results, all particles were spherical and had an anatase structure with an average particle size ranging from 6 nm to 8 nm. There was also a monodisperse distribution in the base fluid. At the highest doping rate (0.3 %) and lowest mass concentration (0.3 %) of Ag-doped particles, the maximum specific heat (3051.31 J/kgK) of the study was observed. Increasing concentration resulted in a maximum 48.2 % decrease in specific heat for nanofluids containing 0.1 % Cu particles. The thermal conductivity increased by 2.40 % with doping but by only 1.89 % with concentration. The highest increase in viscosity was determined as 75.21 % at 40 °C, depending on the concentration increase. Thus, the doping method presents better heat transfer performance without an undesirable increase in viscosity compared to increasing the concentration.

S–CO2 cooling heat transfer mechanism based on pseudo-condensation and turbulent field analysis

The supercritical-CO2 (S–CO2) cooler is one of the main components in S–CO2 power system. This work aims at revealing the cooling mechanism of S–CO2 under wide working conditions to assist the S–CO2 cooler design. The pseudo-condensation is proposed with the analogy between supercritical cooling and subcritical condensation. From the pseudo-condensation and the traditional turbulent field analysis, the specific heat is found to be the dominant parameter for the enhanced heat transfer in S–CO2 cooling. The disappearing of enhanced cooling heat transfer, in the view of pseudo-condensation, is mainly due to the thickening of pseudo liquid film, which is dominated by the gravity force, inertial force and interfacial force in low mass flux flow while the gravity force effect is negligible in high mass flux flow. However, from the turbulent field analysis, the disappearing of enhanced cooling heat transfer is mainly caused by the thickening boundary layer due to the local increase in density and viscosity in addition to the decrease in specific heat. Finally, based on the S–CO2 cooling mechanism, two correlations for predicting heat transfer are proposed and evaluated. The present work can significantly enhance in-depth understanding on S–CO2 cooling and promote engineering application.

Thermophysical Properties and Heat Transfer Performance of Novel Dry-Ice-Based Sustainable Hybrid Lubri-Coolant

It is a well-known fact that the consumption of conventional cutting fluids in metalworking industries leads to severe health and environmental issues. Owing to the EPA (Environmental Protection Agency) increasing regulations regarding pollution and contamination, there is a dire need for a greener fluid with excellent cooling and lubrication characteristics to diminish the environmental impact of cutting fluids, as well as to improve machinability. Cryogens are greener and excellent coolants but poor lubricants, while ester oils are excellent lubricants and poor coolants. Therefore, a hybrid lubri-coolant cutting fluid with synergistic cooling and lubrication characteristics could be a desideratum to replace conventional cutting fluid. To investigate a newly proposed hybrid lubri-coolant, thermophysical properties (density, thermal conductivity, specific heat, and viscosity), heat transfer properties (surface temperature, heat flux, and heat transfer coefficient), and machinability properties (tool life, etc.) are key characteristics of the fluids that decide phase change and heat dissipation capabilities during their application in machining. In the current experimental study, hybrid ethanol–ester oils with/without dry ice (−78 °C) are proposed as cutting fluids and holistically investigated in terms of thermo-physical properties, heat transfer properties, and machinability properties under different cutting conditions. Experimental findings have depicted a 20%, 10%, and 5% decrease in density, specific heat, and viscosity, respectively, with a 15% increase in the thermal conductivity of the fluid with the addition of dry ice. The dry-ice-based hybrid lubri-coolant sprayed onto a Ti-6Al-4V plate enhanced the heat transfer coefficient significantly by 17% compared to hybrid lubri-coolant without dry ice. Besides, hybrid ethanol–ester oil dry ice was treated as a trendsetter and indicated an 11% improvement of the tool life at a cutting speed of 75 m/min and a feed rate of 0.04 mm/z. Therefore, dry-ice-based hybrid lubri-coolant can be applied as a cutting fluid by practitioners in aerospace, automotive, prosthetic body parts manufacturing, and manufacturing industries.

Data-driven analysis of molten-salt nanofluids for specific heat enhancement using unsupervised machine learning methodologies

High specific heat molten-salt is essential for sensible heat thermal energy storage. Current scientific researches focus on Molten-salt nanofluid as a potential solution. However, the causality between system parameters introduced in nanofluid preparation and specific heat enhancement is not clearly understood. Since difficulties are associated with identifying the explicit relations due to complex molecular interactions between molten-salt and nanoparticles, we inquired whether there is a common pattern/clusters in the nanofluid samples reported in earlier studies. The data-driven correlations among samples are explored by employing unsupervised machine learning methods: Hierarchical cluster analysis (HCA) and Principal component analysis (PCA). Three principal components, capturing 81.3% variation of the entire dataset, revealed that the descending order of contribution of the system parameters in the specific heat enhancement percent is concentration, temperature, density ratio, and nanoparticle size. The multivariate clusters emerging from HCA showed the interdependency of density ratio on the temperature, which significantly affects nanofluid's stability at higher concentration, causing a decrease in specific heat enhanced percent. Furthermore, the variation in nanoparticle size was found to have a negligible effect on specific heat enhancement.

Explaining the specific heat of liquids based on instantaneous normal modes

The successful prediction of the specific heat of solids is a milestone in the kinetic theory of matter due to Debye. No such success, however, has ever been obtained for the specific heat of liquids, which has remained a mystery for over a century. A theory of specific heat of liquids is derived here using a recently proposed analytical form of the vibrational density of states of liquids, which takes into account saddle points in the liquid energy landscape via the so-called instantaneous normal modes (INMs), corresponding to negative eigenvalues (imaginary frequencies) of the Hessian matrix. The theory is able to explain the typical monotonic decrease in specific heat with temperature observed in liquids in terms of the average INM excitation lifetime decreasing with T (in accordance with the Arrehnius law) and provides an excellent single-parameter fitting to several sets of experimental data for atomic and molecular liquids. It also correlates the height of the liquid energy barrier with the slope of the specific heat in the function of temperature in accordance with the available data. These findings demonstrate that the specific heat of liquids is controlled by the instantaneous normal modes, i.e., by localized unstable (exponentially decaying) vibrational excitations and provide the missing connection among anharmonicity, saddle points in the energy landscape, and the thermodynamics of liquids.

Usefulness of adding magnetic nano-powders to water: Introducing novel criteria for assessing heat transfer applications

In this study, the usefulness of adding Fe3O4 nanoparticles to water was considered, taking into account the energy demand management. Based on experimental measurements, an increase of 90% and 130% in thermal conductivity and viscosity has been experienced owing to loading Fe3O4. The nanofluid advantage over base fluid is assessed by evaluating the figure of merit (FOM) proposed by various researchers. Taking into account the Prasher, Garj, Lee and Timofeeva criterion, the use of Fe3O4/water nanofluid is acceptable. According to Tesfai criterion, up to 1 vol%, utilizing Fe3O4/water nanofluid has priority over the base fluid. A novel criterion was derived for assessing the heat transfer potential in a smooth tube subjected to constant surface temperature. It was found that the heat transfer potential depends on the number of transfer units (NTU). For NTU > 5, loading nanoparticles decreased the heat transfer potential up to 11% owing to a decrease in specific heat.

Vibrational spectra of MO (M = Sn/Pb) in their bulk and single-layer forms: role of avoided crossing in their thermodynamic properties

We report ab-initio calculations of phonon dispersion relationship on bulk and single layers of SnO and PbO. In agreement with experimental observations of Raman spectroscopy measurement, we find that A1g mode is higher in frequency than Eg mode. Moreover, the reason behind the shift of A2u mode to higher frequency for monolayers of both SnO and PbO is clearly understood from our calculations. In addition to vibrational spectroscopy, we also find avoided crossing or Landau quasi-degeneracy between the longitudinal acoustics (LA) and low-energetic transverse optical (TO) modes in bulk form of both SnO and PbO and in monolayer SnO. The signature of such avoided crossing can be found in the variation of both specific heat and entropy with temperature. Although both specific heat and entropy decrease at the temperature corresponding to the crossing region, the specific heat value shows a kink in that region. In contrast, such lowering/kink in thermodynamic variables does not appear in monolayer PbO. The reason behind the crossing can be analysed using the concept of Born effective charge and dielectric tensor. To further verify the crossing, we calculate phonon group velocity for every band as a function of phonon wave vector for each of these oxides, where the role of avoided crossing has been clearly shown and explained.

PREPARATION AND CHARACTERIZATION OF NANOFLUID (CUO – WATER, TIO2 – WATER)

Over the past decade, research in heat transfer enhancement using nanofluids - suspensions of nanometer-sized solid particles in a base liquid has received considerable attention all over the world. Several theoretical works to predict the effective thermo physical properties of the suspension, range from a homogeneous model to complex two phase flow model have been proposed. This work explains the preparation methods of the nanofluids (CuO-water, TiO2-water) and characterizing the nanofluid of different concentrations (0.025%, 0.05%, 0.075%, 0.1% and 0.5%). Here in this work used to calculate the density, viscosity, specific heat of nanofluids and steady state parallel plate method is used to calculate thermal conductivity of nanofluids experimentally. Results of this work show the increase in thermal conductivity, viscosity of the nanofluid by increasing the concentration and decrease of density and specific heat of nanofluid by increasing the concentration.

Polydimethylsiloxane Based Room Temperature Curable, Low Outgassing and Low Density Thermal Protection System

Thermal protection systems based on hollow particle filled composites emerge as promising material for weight sensitive aerospace applications. The present paper depicts the development of a low outgassing, low density silicone syntactic foam based thermal protection system consisting of hydroxy terminated polydimethylsiloxane (PDMS), micro cells and other additives. The addition of microballoons increases the mechanical strength, while the density could be brought down considerably upto 0.5 g/cc, rendering it suitable for application on metallic and CFRP substrates. Incorporation of a silane-coupling agent was found to improve the adhesion considerably. The system was conferred the consistency for spray coating by suitable rheological modifiers. Though there is a marginal decrease in specific heat, this is offset by a considerable reduction in thermal conductivity to keep the thermal diffusivity on low profile. Mass-loss at 520 K was observed to be less than 1%. The optical properties of the system include IR emissivity in the range of 0.78 and solar absorptivity of 0.17. The system was developed as a room temperature curing, sprayable system and evaluated as a low density thermal protection system for space vehicles for regions intended to experience temperatures up to 650 K. Functional evaluation of the developed system as a topcoat was evaluated by KHS and wind tunnel tests under the test condition for nose cone region of PSLV. During the entire heating simulation, the specimen surface was intact and was stable. The base polymer, PDMS was further subjected to pre-treatment process prior to the compounding to remove the low molecular weight fractions for reducing the outgassing characteristics. The system was further formulated with the same filler formulation so to achieve the low outgassing characteristics while retaining other thermo-physical characteristics. This promising system can find potential application as TPS material for futuristic manned missions.

Computational Modeling on Heat Transfer Enhancement and Fluid Flow Behavior of Al 2 O 3 Water Nanofluid through a Circular Duct

In this work, heat transfer behaviour from a isothermal-walled micro channel has been investigated by using Al2O3-water nanofluid as working fluid. A computational simulation has been carried out for high Reynolds number flow, having different volume fraction of nanoparticles added to it such as; 0%, 1%, 4% and 6%. It has been observed that the properties such as; density, thermal conductivity and viscosity increase with increase in nanoparticles. On the other hand, with increase in the volume fraction of nanoparticles, the specific heat decreases. It also has been observed that the heat transfer from the hot wall increases with Reynolds number and addition of nanoparticles to the nanofluid as well. The friction factor for the flow system decreases with increase the Reynolds number, but for different nanofluids its value is very much closer to each other. With increase in volume fraction of nanoparticles, the pumping power increases. Moreover, with increase in Reynolds number, pumping power increases.

An experimental investigation into the effect of particle mixture ratio on specific heat capacity and dynamic viscosity of Al2O3-ZnO hybrid nanofluids

Hybrid nanofluids are gaining a wide range of applications due to their reported improvement in heat transfer properties. This study presents an experimental investigation into the specific heat and viscosity of Al2O3-ZnO water hybrid nanofluids at three mixture ratios. The specific heat and viscosity measurements are taken over different temperatures at different volume concentrations. The study compared the experimental data to classical models and observed that the specific heat model overestimated and the viscosity model underestimated experimental obtained values. According to results, the particles mixture ratio has a significant effect on both specific heat and viscosity of the hybrid nanofluids. Viscosity increases while specific heat decreases by increasing the volume concentration. Al2O3-ZnO water hybrid nanofluids at 2:1 mixture ratio have a maximum viscosity increase of 96.37% and maximum specific heat decrease of 30.12% at a temperature of 25 °C and volume concentration 1.67%.

Incommensurate Crystallization of Neutron Matter in Neutron Stars

The composition of the neutron stars from its surface region, outer-core, inner-core, and to its center is still being investigated. One can only surmise on the properties of neutron stars from the spectroscopic data that may be available from time to time. A few models have suggested that the matter at the surface region of the neutron star is composed of atomic nuclei that get crushed under extremely large pressure and gravitational stress, and this leads to the creation of solid lattice with a sea of electrons, and perhaps some protons, flowing through the gaps between them. Nuclei with high mass numbers, such as ferrous, gold, platinum, uranium, may exist in the surface region or in the outer-core region. It is found that the structure of the neutron star changes very much as one goes from the surface to the core of the neutron star. The surface region is extremely hard and very smooth. Surface irregularities are hardly of the order of 5 mm, whereas the interior of the neutron star may be superfluid and composed of neutron-degenerate matter. However, the neutron star is highly compact crystalline systems, and in terrestrial materials under pressure, many examples of incommensurate phase transitions have been discovered. Consequently, the properties of incommensurate crystalline neutron star have been studied. The composition of the neutron stars in the super dense state remains uncertain in the core of the neutron star. One model describes the core as superfluid neutron-degenerate matter, mostly, composed of neutrons , and a small percentage of protons and electrons More exotic forms of matter are possible, including degenerate strange matter. It could also be incommensurate crystalline neutron matter that could be BCC or HCP. Using principles of quantum statistical mechanics, the specific heat and entropy of the incommensurate crystalline neutron star has been calculated assuming that the temperature of the star may vary between to . Two values for the temperature T that have been arbitrarily chosen for which the calculations have been done are and . The values of specific heat and entropy decrease as the temperature increases, and also, their magnitudes are very small. This is in line with the second law of thermodynamics.