scholarly journals Development of Predictive Equations for Thermal Conductivity of Compost Bedding

2021 ◽  
Vol 11 (18) ◽  
pp. 8503
Author(s):  
Flávio A. Damasceno ◽  
Joseph L. Taraba ◽  
George B. Day ◽  
Randi A. Black ◽  
Jeffrey M. Bewley ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Particle Size ◽  
Thermal Properties ◽  
Moisture Content ◽  
Scientific Community ◽  
Systematic Investigation ◽  
Bedding Material ◽  
Predictive Equations ◽  
Bedding Materials ◽  
Time And Energy

Among animal facilities, compost-bedded pack (CBP) barns have attracted a lot of attention from milk producers and the scientific community. Systematic investigation of the main thermal properties utilizing sawdust in CBP barns is of environmental and economic relevance. In this paper, the aim was to (a) develop predictive equations for the thermal conductivity (k) of compost bedding as a function of moisture content (MC), the degree of compaction (DCo), and particle size (PS); and (b) investigate the links between k and depth within bedding material. Samples of compost bedding materials were collected from 42 commercial CBP barns distributed throughout Kentucky (USA). From these predictive equations, it was possible to understand how the MC, DCo, and PS of the bedding materials may influence the behavior of k. These results are very useful for solving obstacles to simulate and predict the variable outcomes of the compost bedding materials process in CBP barns, allowing for its optimization, consequently reducing the time and energy spent on their optimization and allowing for simulation and assessment of compost bedding process modifications. The results of the current study may have important implications in the design and management of bedded pack barns.

Investigation of the Properties of Large and Small Fractions of Municipal Solid Waste

2021 ◽  
Vol 25 (6) ◽  
pp. 26-31
Author(s):  
S.V. Polygalov ◽  
G.V. Il’inykh ◽  
N. Stanisavlevich
Keyword(s):  
Particle Size ◽  
Thermal Properties ◽  
Moisture Content ◽  
Fractional Composition ◽  
Ash Content ◽  
Heat Of Combustion ◽  
Laboratory Studies ◽  
Biological Potential ◽  
Solid Municipal Waste ◽  
Biogenic Components

The results of field and laboratory studies of the component and fractional composition of solid municipal waste (MSW), humidity and ash content of MSW components, which made it possible to evaluate the properties of individual fractions and waste in general, are presented. The fractional composition of MSW was determined by the method of separating waste into five fractions of different sizes: more than 250 mm, 100-250 mm, 50–100 mm, 15–50 mm and less than 15 mm. An assessment of the energy and biological potentials of MSW of various sizes has been carried out. In each fraction, the main biogenic components have been identified, which form the biological potential. The calculation of thermal properties (moisture content, ash, combustible substances, as well as the heat of combustion) for the fractions under consideration has been performed. The dependence of the heat of combustion of MSW on the particle size has been established.

scholarly journals THERMAL PROPERTIES OF MALAYSIAN COHESIVE SOILS

2016 ◽  
Vol 78 (8-5) ◽  
Author(s):  
Adriana Amaludin ◽  
Aminaton Marto ◽  
Muhd. Hatta M. Satar ◽  
Hassanel Amaludin ◽  
Salinah Dullah
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Moisture Content ◽  
Specific Heat ◽  
Cohesive Soil ◽  
Linear Increase ◽  
Thermal Resistivity ◽  
Soil Matrix ◽  
Volumetric Specific Heat ◽  
Shallow Geothermal Energy

The thermal properties of soils surrounding energy piles are required for the efficient and optimal design of shallow geothermal energy pile systems. In this study, the thermal conductivity, thermal resistivity and volumetric specific heat of two types of Malaysian cohesive soil were obtained through a series of laboratory experiments using a thermal needle probe. This study was conducted to determine the effect of moisture content on the thermal conductivity, thermal resistivity and volumetric specific heat values of the cohesive soil at a given value of soil density. For soils with low to medium moisture content, a linear increase in the thermal conductivity and volumetric heat capacity was observed as the moisture content gradually increased, while the thermal resistivity values of the soil had decreased. Meanwhile, for soils with high moisture content, the thermal conductivity was observed to have decreased, and a marked increase was seen in the thermal resistivity. This is due to the disruption of the thermal flow continuity in the soil matrix with the presence of moisture in the soil which adversely affects the thermal conductivity

An Analysis of a Method of In-Situ Thermal Properties Determination for Geologic Formations

1985 ◽  
Vol 107 (1) ◽  
pp. 122-127
Author(s):  
J. D. Lin ◽  
T. J. Love
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Moisture Content ◽  
Oil Recovery ◽  
Thermal Methods ◽  
Core Samples ◽  
Time Required ◽  
And Storage ◽  
Flux Probe

Geothermal investigations and thermal methods of oil recovery require the thermal properties of rock be known. The thermal conductivity of rock is normally determined by measuring the properties of core samples which have been removed from the well. The major problem with this is the fact that thermal properties are dependent on the moisture content of the rock. This moisture content is very likely altered in transportation and storage. This paper presents an analysis which serves as the basis of a transient heat flux probe measurement that may be used to determine the thermal conductivity and diffusivity in situ. Such in-situ measurements would overcome the disadvantages of core samples and may also be used when core samples are not available. This analysis also provides a method of estimating the time required in order to obtain valid results. The analysis indicates rather long test times may be required for accurate results. However, it does provide a basis for evaluating the results of measurements taken for shorter times. The effects of contact thermal resistance between the probe, the well casing, and the formation are evaluated.

Thermal Properties of Selected Timbers

2014 ◽  
Vol 982 ◽  
pp. 100-103 ◽  
Author(s):  
Dana Koňáková ◽  
Monika Čáchová ◽  
Eva Vejmelková ◽  
Martin Keppert ◽  
Robert Černý
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Properties ◽  
Moisture Content ◽  
Specific Heat ◽  
Heat Transport ◽  
Specific Heat Capacity ◽  
Open Porosity ◽  
Building Structures ◽  
The Difference

This article deals with thermal properties of selected kinds of timber. Wood, generally, is one of often used natural materials in building structures. For our research, woods were selected according to frequency of utilization in civil engineering branch. Four different timbers were chosen, and experimental determinations of their properties were performed. Basic physical properties as well as thermal properties belong among studied characteristics. From achieved results, it is obvious, that the bulk density of studied wood ranges between 373 kg m-3 and 649 kg m-3, the open porosity differ by 13%. Regarding thermal properties, values of the thermal conductivity as well as the specific heat capacity are influenced mainly by the open porosity and moisture content. The thermal conductivity in dry state varies by about 31% while in the case of the specific heat capacity the difference is about 19%. Obtained date will be used in the mathematical analysis of heat transport in building structures.

scholarly journals Effect of moisture content on the thermal properties of Horse-Eye Bean seeds relevant to its processing

2020 ◽  
Vol 45 (4) ◽  
pp. 71-80
Author(s):  
Ide Ejike ◽  
Ike Oluka ◽  
Eze Chukwuka
Keyword(s):  
Thermal Conductivity ◽  
Regression Analysis ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Moisture Content ◽  
Specific Heat ◽  
Bulk Density ◽  
Food Processing ◽  
Positive Relationship ◽  
Measured Specific Heat

The specific heat, thermal conductivity and thermal diffusivity of the Horse-Eye bean (Mucuna sloanei) were determined as a function of moisture content using the method reported by A.O.A.C (2000). The sample varieties used were the Big Sized and the Small Sized Horse-Eye bean. The specific heat and the thermal conductivity were measured using a Bomb Calorimeter. The thermal diffusivity was calculated from the measured specific heat, thermal conductivity and bulk density of the samples. Within the moisture range of 10.5% to 16.87% (b.b), the specific heat, thermal conductivity and thermal diffusivity varied with the moisture content. Results showed that the specific heat, thermal conductivity and thermal diffusivity of the Horse-Eye bean seeds ranged from 116.76 to 203.29 kJ/kgK; 21.07 to 32.23 W/moC; and 3.12 x 10-7 to 9.19 x 10-7 m 2 /s, for the Big Sized varieties, and 112.06 to 194.61 kJ/kgK; 19.85 to 24.08 W/moC; and 3.05 x 10-7 to 6.71 x 10-7 m 2 /s, for the Small Sized varieties as the moisture content increases from 10.5% to 16.87%. Regression analysis were also carried out on the thermal properties of the Horse-Eye bean varieties and moisture content, and there was positive relationship between the parameters. There were significant effects of moisture content (p < 0.05) on all the parameters conducted. The findings and the data generated will create an impact in the food processing industries for Horse-Eye bean.

Effect of Nanosilica on Mechanical and Thermal Properties of Cement Composites for Thermal Energy Storage Materials

2015 ◽  
Vol 1131 ◽  
pp. 182-185
Author(s):  
Pongsak Jittabut
Keyword(s):  
Thermal Conductivity ◽  
Particle Size ◽  
Heat Capacity ◽  
Compressive Strength ◽  
Thermal Properties ◽  
Thermal Energy ◽  
Energy Storage Materials ◽  
Mechanical And Thermal Properties ◽  
Storage Materials ◽  
Nanosilica Particle

This research article presents the mechanical and thermal properties of cement-based composite for thermal energy storage materials. The effects of nanosilica particle size and concentration determined by mixing nanosilica particle size of 50 nm, using nanosilica were of 1-5 wt%. Thermal properties coefficients were tested using a direct measuring instrument with surface probe (ISOMET2114). The influence of nanosilica on the performance, such as compressive strength, bulk density, thermal conductivity, volume heat capacity and thermal diffusivity of hardened composite cement pastes were studied for future solar thermal energy materials with better performance. According to the development of thermal storage materials and their application environment requirement in solar thermal power, the specimens were subjected to heat at 350, and 900°C. It were observed that, before heating, the compressive strength is optimized at nanosilica amount of 4wt% at the age of 28 days. Moreover, after heating at 350 oC and 900°C, the thermal conductivity and volume heat capacity of the cement paste enriched with nanosilica were significantly lesser than that of the before heating one.

Study of the Impact of Rice Straw Particle Size on the Mechanical and Thermal Properties of Straw Lime Concretes

2022 ◽  
Author(s):  
Youssef El Moussi ◽  
Laurent Clerc ◽  
Jean-Charles Benezet
Keyword(s):  
Thermal Conductivity ◽  
Particle Size ◽  
Compressive Strength ◽  
Thermal Properties ◽  
Water Absorption ◽  
Rice Straw ◽  
Absorption Capacity ◽  
Mechanical And Thermal Properties ◽  
Water Absorption Capacity ◽  
The Impact

The use of bio-based concretes performed with lignocellulosic aggregates constitute an interesting solution for reducing the energy consumption, greenhouse gas emissions and CO2 generated by the building sector. Indeed, bio-based materials could be used as an alternative of traditional materials such as expended polystyrene and mineral resources (e.g. glass and rock wools) for insulation. Furthermore, these bio-based concretes are known for their interesting insulation properties, indeed they allow to enhance thermal properties of buildings and enables moisture management which lead to design efficient building materials. For this purpose, bio-based concrete using rice straw as aggregate are studied in this present work. The impact of the characteristics of rice straw particle (particle size distribution, bulk density, and water absorption capacity, etc.) on both the mechanical and thermal properties of the bio-based concrete are investigated. Five formulations of rice straw concrete are examined, compared and then classified in terms of insulation properties and mechanical properties. The assessments are based on the measurement of density and thermal conductivity. The variation of compressive strength in function of the characteristics (mean particle length) of rice straw particle are assessed and discussed. The investigation covers also the porosity and density. Tests are also carried out on agricultural by-products with a view to highlight their chemical, physical and structural proprieties. The results show that the use of large particles with low water absorption capacity induce lighter concretes with the density between 339 and 505 kg/m3 and lead to a high compressive strength with a high mechanical deformability. Furthermore, it appears that an increase in the average length of rice straw particle lead to decrease of thermal conductivity of bio-based concretes. It varies from 0.062 to 0.085 W/(m.K).

Moisture-dependent Physical and Thermal Properties of Sericea Lespedeza Seeds

2019 ◽  
Vol 35 (3) ◽  
pp. 389-397
Author(s):  
Ajit K Mahapatra ◽  
Daniel E Ekefre ◽  
Hema L Degala ◽  
Somashekhar M Punnuri ◽  
Thomas H Terrill
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Moisture Content ◽  
Specific Heat ◽  
Geometric Mean ◽  
Seed Mass ◽  
Angle Of Repose ◽  
Engineering Properties ◽  
Sericea Lespedeza ◽  
Mean Diameter

Abstract. The bioactivity of Sericea lespedeza (SL) condensed tannins, including suppression of gastrointestinal nematodes, has contributed to a surge in interest of use of this plant in livestock production systems worldwide. Physical and thermal properties of SL seeds (AU Grazer™ and Serala cultivars) were determined as a function of moisture content for a moisture range from 8.57% to 26.53%, wet basis. The length, width, arithmetic mean diameter, geometric mean diameter, surface area, volume, and 1000 seed mass of both the seeds increased as the moisture content increased. Bulk density and unit density decreased as the moisture content increased. The sphericity of SL seeds decreased with increasing moisture content. Serala seeds were characterized by a higher aspect ratio than AU Grazer™. The angle of repose of SL seeds increased, while the compressibility index decreased in the moisture range. For color, the L* values of SL seeds decreased while the a* values increased with the increase in moisture content. A decrease in the b* values was insignificant. The thermal conductivity and specific heat of SL seeds decreased, whereas, thermal diffusivity increased as the moisture content of SL seeds increased. Serala seeds were characterized by higher values of thermal conductivity and volumetric specific heat than AU Grazer™. Keywords: Engineering properties, Moisture content, Physical properties, Seeds, Thermal properties.

Effect of Plant Fibres on the Variability of Cob Materials

2022 ◽  
Author(s):  
Junior Tchiotsop ◽  
Nabil Issaadi ◽  
Philippe Poullain ◽  
Stéphanie Bonnet
Keyword(s):  
Thermal Conductivity ◽  
Particle Size ◽  
Heat Capacity ◽  
Organic Matter ◽  
Thermal Properties ◽  
High Variability ◽  
Mean Values ◽  
Flax Fibres ◽  
Fibre Composites ◽  
Particle Screening

Earthen materials have different nature components and present a high variability comparing to conventional materials; researchers try to settle it down for a future normalization as environmentally efficient material. But there is a need in energy to do it, either directly (compaction, organic matter extraction, particle screening to get the best particle size distribution ...) or indirectly by including inefficient materials from an environmental perspective (cement, limestone ...). The aim of this study is to follow the variability problematic of cob materials by comparing and understanding variation level of the hygrothermal characteristics due to fibres nature and fibres content. We found that plant fibres (hemp, flax and hay) act as a stabilizer for dry bulk density; at 1% fibres substitute, hemp fibre composites show the highest coefficient of variation on the thermal properties (6.1% on thermal conductivity, 18.74% on specific heat capacity) but flax fibres show the highest mean values. Increasing hay stalk content induces the spread of the hygrothermal properties inside their range of variaation.

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.

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