scholarly journals Applying the EDPS Method to the Research into Thermophysical Properties of Solid Wood of Coniferous Trees

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Ľuboš Krišťák ◽  
Rastislav Igaz ◽  
Ivan Ružiak
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Diffusivity ◽  
Moisture Content ◽  
Thermophysical Properties ◽  
Solid Wood ◽  
Plane Source ◽  
Coniferous Trees ◽  
Extended Dynamic ◽  
Dynamic Plane

The results of using the EDPS (extended dynamic plane source) method to determine thermophysical properties of solid wood of coniferous trees growing in Slovakia with 0% and 12% equilibrium moisture content are presented in the paper. Solid wood of two different tree species: Norway spruce (Picea abies L.) and Scots pine (Pinus sylvestris L.) was used in the research. The research was carried out independently in three anatomical planes. Coefficients of thermal conductivity, thermal diffusivity, and specific heat capacity were determined following the research. Comparing the research results to the values determined by other authors and already published models to calculate individual parameters, the fact that the data gathered using the EDPS method can be accepted in case of all studied thermophysical properties can be stated.

scholarly journals Thermophysical properties of OSB boards versus equilibrium moisture content

BioResources ◽  
2017 ◽  
Vol 12 (4) ◽  
pp. 8106-8118
Author(s):  
Rastislav Igaz ◽  
Ľuboš Krišťák ◽  
Ivan Ružiak ◽  
Milada Gajtanska ◽  
Martin Kučerka
Keyword(s):  
Thermal Conductivity ◽  
Moisture Content ◽  
Experimental Method ◽  
Thermophysical Properties ◽  
Finite Geometry ◽  
Anisotropic Materials ◽  
Thermal Capacity ◽  
Regression Equations ◽  
Extended Dynamic ◽  
Dynamic Plane

The basic thermophysical properties of oriented strand boards were determined experimentally for use in humid conditions (OSB3) depending on the moisture content. The dependency between the thermal conductivity, thermal diffusivity, specific heat capacity, and the moisture content in the range of 0% to 10%, was examined. The non-stationary extended dynamic plane source (EDPS) experimental method was used. EDPS method was modified for anisotropic materials, i.e. with special considerations of heat-loss effect occurring at the edge of measuring samples, finite geometry of the sample and orthotropic thermal conductivity, for use with anisotropic materials. The validity of the experimental method was verified on polymethylmethacrylate (PMMA) samples. The error rate of measurements conducted on PMMA samples was less than 3%, and for OSB3 boards it was less than 5.5%. Based on the experimental results, regression equations of the dependency between the monitored properties and the moisture content were determined. In the case of thermal conductivity and thermal capacity, the determined dependencies showed a high correlation rate.

scholarly journals Thermophysical properties of BiFeO3/REE multiferroics in a wide temperature range

2020 ◽  
Vol 10 (01n02) ◽  
pp. 2060019
Author(s):  
Sidek Khasbulatov ◽  
Suleiman Kallaev ◽  
Haji Gadjiev ◽  
Zairbek Omarov ◽  
Abumuslim Bakmaev ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Rare Earth ◽  
High Temperature ◽  
Thermal Diffusivity ◽  
Rare Earth Elements ◽  
Wide Temperature Range ◽  
Thermophysical Properties ◽  
Multiferroic Bifeo ◽  
Comprehensive Study

The paper presents the results of a comprehensive study of the thermophysical properties (thermal conductivity, thermal diffusivity, heat capacity) of high-temperature multiferroic BiFeO3 modified with rare-earth elements (REEs) (La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Lu). The regularities of the formation of the mentioned characteristics were established. The assumptions about the nature of the observed phenomena were suggested.

scholarly journals Thermophysical properties of NP2 brand nickel

2021 ◽  
Vol 2119 (1) ◽  
pp. 012135
Author(s):  
D A Samoshkin ◽  
A Sh Agazhanov ◽  
S V Stankus
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Diffusivity ◽  
Thermophysical Properties ◽  
Magnetic Phase ◽  
Laser Flash ◽  
Scanning Calorimetry ◽  
Reference Table ◽  
Laser Flash Technique ◽  
Flash Technique

Abstract The heat capacity and the thermal diffusivity of NP2 brand nickel were investigated in the temperature interval 296–1000…1375 K of the solid-state, including the region of the magnetic phase transformation. Measurements were carried out on samples from one initial ingot by laser flash technique and method of differential scanning calorimetry using LFA-427 and DSC 404 F1 setups, respectively. The thermal conductivity was calculated based on the measured thermophysical properties. The estimated errors of the obtained results were 2–4%, 3–5%, and 2–3% for thermal diffusivity, thermal conductivity, and heat capacity, respectively. For investigated thermophysical properties the fitting equations and the reference table have been received.

scholarly journals Effect of Wheat Straw Biochar on Thermophysical Properties of Loessial Soil

2021 ◽  
Vol 20 (3) ◽  
Author(s):  
B. W. Zhao ◽  
Y. Zhao ◽  
H. Liu ◽  
Y. Q. Li ◽  
K. X. Duan ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Diffusivity ◽  
Water Content ◽  
Thermophysical Properties ◽  
Heat Balance ◽  
Pyrolysis Temperature ◽  
Internal Heat ◽  
Loessial Soil ◽  
Biochar Amendment

Soil thermophysical properties are the key factors affecting the internal heat balance of soil. In this paper, biochars (BC300, BC500 and BC700) were produced with wheat straw at the temperatures of 300, 500 and 700°, respectively. The effects of biochar amendment at the rates of 0%, 1%, 3%, and 5% on the thermophysical properties (thermal conductivity, heat capacity, and thermal diffusivity) of a loessial soil were investigated with and without water content respectively. Although the bulk density of soil significantly decreased with biochar amendment, due to enhancing soil porosity and organic matter content, the thermophysical properties of soil did not change largely with biochar amendment rate and pyrolysis temperature. Water content exhibited significant effects on the thermophysical properties of soils added with biochars, where the thermal conductivity and heat capacity of soil were linearly proportional to water content, the thermal diffusivity initially increased and then decreased with the increase of water content. In the meanwhile, there was no significant correlation between the biochar amendment rate or pyrolysis temperature and thermophysical properties. The results show that water content should be mainly concerned as a factor when the internal heat balance of loess soil is evaluated, even though the soil is amended with biochar.

scholarly journals The effect of artificial forest plantations on the thermophysical properties of chernozems

2019 ◽  
Vol 30 (1) ◽  
pp. 33-38
Author(s):  
V. A. Gorban
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Diffusivity ◽  
Air Temperature ◽  
Thermophysical Properties ◽  
Soil Surface ◽  
Maximum Temperature ◽  
Ordinary Chernozem ◽  
Forest Plantations ◽  
Average Temperature

As a result of a study of the effect of artificial forest plantations formed by Robinia pseudoacacia L. and Quercus robur L., on the thermophysical features of the chernozems of the Komissarovsky reserve (Pyatykhatsky district, Dnepropetrovsk region, Ukraine), it was found that the stand of robinia reduced air temperature by 4, 5 °С, oak – by 9.4 °С in comparison with the open area. The maximum temperature of the soil surface is found in ordinary chernozem. The effect of robinia plantation manifested itself in the form of a decrease in the temperature of the soil surface by 5.4 °C, and the oak surface by 8.0 °C. The maximum soil temperature at a depth of 50 cm is also found in ordinary chernozem. At the same depth, the soil under robinia plantation turned out to be 7.6 °C, under oak – 6.9 °C colder. According to the average temperature of the 50-centimeter layer of all the studied soils, ordinary chernozem is distinguished, the soils under the plantations almost do not differ according to this indicator. The smallest difference between the air temperature and the average temperature of the soil layer 0–50 cm was in the soil under oak plantation, the largest – in the soil under robinia plantation. The smallest difference between the temperature of the soil surface and at a depth of 50 cm was found in the soil under oak plantation, and the greatest difference in the soil under robinia plantations. Based on the analysis of the results obtained, an assumption was made about the thermal features of the upper horizons, which fall within the interval of 0–50 cm, of each of the three studied soils. The soil under robinia plantation is characterized by maximum values of thermal diffusivity, and ordinary chernozem – minimal. The soil under the oak plantation occupies an intermediate value for this indicator. Ordinary chernozem is characterized by maximum values of heat capacity, slightly smaller values are characteristic of soil for robinia plantations. The minimum values of heat capacity are characteristic of oak plantation soil. The soil under robinia plantation is sharply distinguished by the maximum values of thermal conductivity compared to ordinary chernozem and the soil under oak planting. The actual study of thermophysical properties confirmed the correctness of the assumption in only one of the three indicators for each of the studied soils. This indicates a significant limitation of predicting the thermophysical indicators of soils, based only on measuring their temperature. The influence of robinia plantation on the thermal physical properties of ordinary chernozems is manifested in an increase in their thermal diffusivity and thermal conductivity, as well as in a certain decrease in heat capacity. The influence of oak stands is characterized by an increase in thermal diffusivity and heat capacity, as well as a decrease in thermal conductivity of ordinary chernozem.

scholarly journals Thermal properties of soursop seeds and kernels

2017 ◽  
Vol 63 (No. 2) ◽  
pp. 79-85 ◽  
Author(s):  
Tunji Oloyede Christopher ◽  
Bukola Akande Fatai ◽  
Olaniyi Oriola Kazeem ◽  
Oluwatoyin Oniya Oluwole
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Moisture Content ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Oil Recovery ◽  
Thermal Analyser ◽  
Selection Of

The thermal properties of soursop seeds and kernels were determined as a function of moisture content, ranged from 8.0 to 32.5% (d.b.). Three primary thermal properties: specific heat capacity, thermal conductivity and thermal diffusivity were determined using Dual-Needle SH-1 sensors in KD2-PRO thermal analyser. The obtained results shown that specific heat capacity of seeds and kernels increased linearly from 768 to 2,131 J/kg/K and from 1,137 to 1,438 J/kg/K, respectively. Seed thermal conductivity increased linearly from 0.075 to 0.550 W/m/K while it increased polynomially from 0.153 to 0.245 W/m/K for kernel. Thermal diffusivity of both seeds and kernels increased linearly from 0.119 to 0.262 m<sup>2</sup>/s and 0.120 to 0.256 m<sup>2</sup>/s, respectively. Analysis of variance results showed that the moisture content has a significant effect on thermal properties (p ≤ 0.05). These values indicated the ability of the material to retain heat which enhances oil recovery and can be used in the design of machine and selection of suitable methods for their handling and processing.

Determining Thermal Properties of Insulating Sleeves

2010 ◽  
Vol 649 ◽  
pp. 487-491 ◽  
Author(s):  
Witold K. Krajewski ◽  
Józef Szczepan Suchy
Keyword(s):  
Thermal Conductivity ◽  
Mass Transfer ◽  
Heat Capacity ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Boundary Conditions ◽  
Thermophysical Properties ◽  
Mean Values ◽  
Computer Aided ◽  
The Mean

The presented work is aimed at determining thermal diffusivity, thermal conductivity and heat capacity of insulating sleeves used in Polish metallurgical/foundry practice. On basis of the theory elaborated in [1] the mean values of thermophysical properties for temperatures range of about 150-1000 oC were obtained. The results obtained during the examinations presented in the paper can be helpful when formulating boundary conditions during the computer aided simulation of the processes of heat and mass transfer in the system: casting (ingot) – mould riser (ingot head) – ambient, which uses the investigated insulating sleeves [2, 3]. The method of determining thermal properties can be also used for other foundry materials, e.g. sands or cores.

scholarly journals Influence of Moisture and Temperature on the Thermal Properties of Jack Bean Seeds (Canavalia ensiformis)

2021 ◽  
Author(s):  
Jelili Hussein ◽  
Moruf Olanrewaju Oke ◽  
Kazeem Olaniyi Oriola ◽  
Abimbola Ajetunmobi
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Moisture Content ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Jack Bean ◽  
Canavalia Ensiformis ◽  
Thermal Analyzer

The thermal properties (specific heat capacity, thermal conductivity, and thermal diffusivity) of jack bean seed (Canavalia ensiformis) were determined for usage in designing the equipment necessary for thermal processes. These thermal properties were determined at 5, 10, 15, 20, and 25 % moisture contents (wb) and temperatures at 30, 40, and 50oC using the KD2 Pro thermal analyzer. Results showed that the specific heat capacity ranged from 1.55 to 2.47 kJ/kgK, 1.26 to 1.84 kJ/kgK and 1.32 to 1.99 kJ/kgK; thermal conductivity 0.21 to 0.47 W/mK, 0.34 to 0.52 W/mK, and 0.26 to 0.60 W/mK and thermal diffusivity 0.25 to 0.41 x 10-7 m²/s, 0.32 to 0.57 x 10-7 m²/s, and 0.32 to 0.60 x 10-7 m²/s at 30, 40, and 50°C respectively for the moisture ranges studied. The temperature and moisture content effect were not significant (p>0.05) with specific heat and thermal diffusivity but significant (p<0.05) with thermal conductivity in third-order polynomial. A non-linear relationship was established between the three thermal properties and moisture content within the studied temperature range. The resulting regression models for the thermal properties gave a high coefficient of determinations (R2 ≥ 0.7995) which implies that they can be used to describe the relationships between temperature, moisture, and thermal properties of jack bean seeds.

Sign in / Sign up

Export Citation Format

Share Document