scholarly journals Thermal properties of representative soils of the Czech Republic

2013 ◽  
Vol 8 (No. 4) ◽  
pp. 141-150 ◽  
Author(s):  
R. Kodešová ◽  
M. Vlasáková ◽  
M. Fér ◽  
D. Teplá ◽  
O. Jakšík ◽  
...  

Knowledge of soil thermal properties is essential when assessing heat transport in soils. Thermal regime of soils is associated with many other soil processes (water evaporation and diffusion, plant transpiration, contaminants behaviour etc.). Knowledge of thermal properties is needed when assessing effectivity of energy gathering from soil profiles using horizontal ground heat exchangers, which is a topic of our research project. The study is focused on measuring of thermal properties (thermal conductivity and heat capacity) of representative soils of the Czech Republic. Measurements were performed on soil samples taken from the surface horizons of 13 representative soil types and from 4 soil substrates, and on mulch (bark chips) sample using KD2 PRO device with TR-1 and SH-1 sensors. The measured relationships between the thermal conductivity and volumetric soil-water content were described by the non-linear equations and those between the volumetric heat capacity and volumetric soil-water content were expressed using the linear equations. The highest thermal conductivities were measured in soils on quartz sand substrates. The lowest thermal conductivities were measured in the Stagnic Chernozem Siltic on marlite and the Dystric Cambisol on orthogneiss. The opposite trend was observed for maximal heat capacities, i.e. the highest values were measured in the Stagnic Chernozem Siltic and the lowest in sand and soils on sand and sandy gravel substrate.

2018 ◽  
Vol 10 (6) ◽  
pp. 97-105 ◽  
Author(s):  
Morgan Amanda ◽  
Joseph Pearson Brian ◽  
Shad Ali Gul ◽  
Moore Kimberly ◽  
Osborne Lance

2020 ◽  
Author(s):  
Tangtang Zhang ◽  
Xin Ma

<p>Soil temperature, soil water content and soil thermal properties were measured in an artificial forestland and a natural regrowth grassland from November in 2017 to July in 2019. The results show that the effects of soil temperature and soil water content on thermal properties are different in different soil condition. Soil thermal conductivity (K) and soil volumetric heat capacity (C) increase with increasing temperature in unfrozen period, but soil diffusivity (D) has no significant dynamic cycle and it almost keeps a constant level in a certain time. Soil thermal conductivity (K) decreases with increasing temperature during soil frozen period. The C and K increase with increasing soil water content in unfrozen period, while the D decrease with increasing soil water content.</p>


Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7663
Author(s):  
Kaoutar Zeghari ◽  
Ayoub Gounni ◽  
Hasna Louahlia ◽  
Michael Marion ◽  
Mohamed Boutouil ◽  
...  

This paper emphasizes the experimental and numerical study of new cob mixes used for insulation and load bearing wall elements. The experimental study provides complete datasets of thermal properties of the new walling materials, using cob with density ranging from 1107 kg/m3 to 1583 kg/m3 for structural walls and less than 700 kg m−3 for insulation walls. Various mixes of French soils and fibres (reed, wheat straw, hemp shiv, hemp straw, and flax straw) with different water contents are studied. The lowest average thermal conductivity is obtained for the structural cob mix prepared of 5% wheat straw and 31% of water content. The insulation mix, prepared with 25% reed and 31% water content, has the lowest thermal conductivity. Investigation of diffusivity, density, and heat capacity shows that, when thermal conductivity is lower than 0.4 W m−1 K−1, the decrease in cob density leads to better insulation values and higher heat capacity. Little variation is noticed regarding the density and heat capacity for cob mixes with thermal conductivity higher than 0.4 W m−1 K−1. Furthermore, the non-uniformity of local thermal conductivity and heat losses through the samples is due mainly to the non-uniform distribution of fibres inside the mixes inducing an increase in heat loss up to 50% for structural walls and 25% for insulation walls. Cob thermal properties are used in a comparative simulation case study of a typical house under French and UK climatic conditions. The energy performance of the conventional building is compared to a dual walled cob building, showing remarkable reduction in energy consumption as the cob walls, whilst maintaining comfortable indoor conditions without additional heating.


HortScience ◽  
2008 ◽  
Vol 43 (3) ◽  
pp. 952-954 ◽  
Author(s):  
Jorge A. Zegbe ◽  
M. Hossein Behboudian ◽  
Brent E. Clothier ◽  
Alexander Lang

Quality and storability of ‘Pacific Rose™’ apple grown under partial rootzone drying (PRD) were studied over 2 years. The treatments were commercial irrigation (CI) and PRD, which were applied by watering one side of the tree row throughout the season (Expt. 1) or by alternating irrigation between two sides of the tree row when volumetric soil water content ranged between 0.18 and 0.22 m3·m−3 (Expt. 2). The PRD and CI fruit had similar quality attributes at harvest and after storage except that the former had lower weight loss during storage in Exp. 1 and a lower firmness after storage in Exp. 2. Compared with CI, PRD saved water by 0.15 mega liters per hectare in Exp. 1 and by 0.14 mega liters per hectare in Exp. 2. We recommend PRD for humid environments similar to ours.


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