Specific heat and thermal conductivity of the triangular-lattice rare-earth material 
KBaYb(BO3)2
 at ultralow temperature

The temperature dependence of the heat capacity of the multiferroics BiFeO3, Bi0.90Sm0.10FeO3, and Bi0.90Eu0.10FeO3 has been studied. It was found that the substitution of europium and samarium ions for bismuth ions in bismuth ferrite leads to the appearance of an additional heat capacity component due to transitions of 4f - electrons of rare earth ions to higher levels of the multiplet. A connection is established between the decrease in phonon thermal conductivity and the Schottky effect for the specific heat.

Download Full-text

Information about the phonon spectrum of some rare earth ethyl sulfates from the specific heat and the thermal conductivity

Physics Letters ◽

10.1016/0031-9163(63)90619-x ◽

1963 ◽

Vol 7 (2) ◽

pp. 95-96 ◽

Cited By ~ 1

Author(s):

A.M. De Graaf ◽

J.A. Sussmann

Keyword(s):

Thermal Conductivity ◽

Rare Earth ◽

Specific Heat ◽

Phonon Spectrum

Download Full-text

SPECIFIC HEAT AND THERMAL CONDUCTIVITY OF TmVO4 AND DyVO4 WITH AN APPLIED MAGNETIC FIELD

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1981681 ◽

1981 ◽

Vol 42 (C6) ◽

pp. C6-277-C6-279 ◽

Cited By ~ 1

Author(s):

B. Daudin ◽

B. Salce ◽

S. H. Smith

Keyword(s):

Magnetic Field ◽

Thermal Conductivity ◽

Specific Heat ◽

Applied Magnetic Field

Download Full-text

Thermal Characterization of Carbon-Carbon Composites

Volume 10: Heat and Mass Transport Processes, Parts A and B ◽

10.1115/imece2011-64061 ◽

2011 ◽

Author(s):

Messiha Saad ◽

Darryl Baker ◽

Rhys Reaves

Keyword(s):

Thermal Conductivity ◽

Thermal Properties ◽

Thermal Diffusivity ◽

Specific Heat ◽

Critical Role ◽

Carbon Composite ◽

Flash Method ◽

Carbon Composites ◽

Energy Storage Devices ◽

Graphitized Carbon

Thermal properties of materials such as specific heat, thermal diffusivity, and thermal conductivity are very important in the engineering design process and analysis of aerospace vehicles as well as space systems. These properties are also important in power generation, transportation, and energy storage devices including fuel cells and solar cells. Thermal conductivity plays a critical role in the performance of materials in high temperature applications. Thermal conductivity is the property that determines the working temperature levels of the material, and it is an important parameter in problems involving heat transfer and thermal structures. The objective of this research is to develop thermal properties data base for carbon-carbon and graphitized carbon-carbon composite materials. The carbon-carbon composites tested were produced by the Resin Transfer Molding (RTM) process using T300 2-D carbon fabric and Primaset PT-30 cyanate ester. The graphitized carbon-carbon composite was heat treated to 2500°C. The flash method was used to measure the thermal diffusivity of the materials; this method is based on America Society for Testing and Materials, ASTM E1461 standard. In addition, the differential scanning calorimeter was used in accordance with the ASTM E1269 standard to determine the specific heat. The thermal conductivity was determined using the measured values of their thermal diffusivity, specific heat, and the density of the materials.

Download Full-text

Influence of alkaline modification on selected properties of banana fiber paperbricks

Scientific Reports ◽

10.1038/s41598-021-85106-8 ◽

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.

Download Full-text

Thermophysical Properties of Cement Mortar Containing Waste Glass Powder

Crystals ◽

10.3390/cryst11050488 ◽

2021 ◽

Vol 11 (5) ◽

pp. 488

Author(s):

Oumaima Nasry ◽

Abderrahim Samaouali ◽

Sara Belarouf ◽

Abdelkrim Moufakkir ◽

Hanane Sghiouri El Idrissi ◽

...

Keyword(s):

Thermal Conductivity ◽

Specific Heat ◽

Thermophysical Properties ◽

Glass Powder ◽

Cement Mortar ◽

Soda Lime ◽

Waste Glass ◽

Soda Lime Glass ◽

Volumetric Specific Heat ◽

Waste Glass Powder

This study aims to provide a thermophysical characterization of a new economical and green mortar. This material is characterized by partially replacing the cement with recycled soda lime glass. The cement was partially substituted (10, 20, 30, 40, 50 and 60% in weight) by glass powder with a water/cement ratio of 0.4. The glass powder and four of the seven samples were analyzed using a scanning electron microscope (SEM). The thermophysical properties, such as thermal conductivity and volumetric specific heat, were experimentally measured in both dry and wet (water saturated) states. These properties were determined as a function of the glass powder percentage by using a CT-Meter at different temperatures (20 °C, 30 °C, 40 °C and 50 °C) in a temperature-controlled box. The results show that the thermophysical parameters decreased linearly when 60% glass powder was added to cement mortar: 37% for thermal conductivity, 18% for volumetric specific heat and 22% for thermal diffusivity. The density of the mortar also decreased by about 11% in dry state and 5% in wet state. The use of waste glass powder as a cement replacement affects the thermophysical properties of cement mortar due to its porosity as compared with the control mortar. The results indicate that thermal conductivity and volumetric specific heat increases with temperature increase and/or the substitution rate decrease. Therefore, the addition of waste glass powder can significantly affect the thermophysical properties of ordinary cement mortar.

Download Full-text