Influence of Mesocarp Fibre Inclusion on Thermal Properties of Foamed Concrete

2021 ◽  
Vol 87 (1) ◽  
pp. 1-11
Author(s):  
Siti Shahirah Suhaili ◽  
Md Azree Othuman Mydin ◽  
Hanizam Awang
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Volume Fraction ◽  
Thermal Constant ◽  
Volume Fractions ◽  
Foamed Concrete

The addition of mesocarp fibre as a bio-composite material in foamed concrete can be well used in building components to provide energy efficiency in the buildings if the fibre could also offer excellent thermal properties to the foamed concrete. It has practical significance as making it a suitable material for building that can reduce heat gain through the envelope into the building thus improved the internal thermal comfort. Hence, the aim of the present study is to investigate the influence of different volume fractions of mesocarp fibre on thermal properties of foamed concrete. The mesocarp fibre was prepared with 10, 20, 30, 40, 50 and 60% by volume fraction and then incorporated into the 600, 1200 and 1800 kg/m3 density of foamed concrete with constant cement-sand ratio of 1:1.5 and water-cement ratio of 0.45. Hot disk thermal constant analyser was used to attain the thermal conductivity, thermal diffusivity and specific heat capacity of foamed concrete of various volume fractions and densities. From the experimental results, it had shown that addition of mesocarp fibre of 10-40% by volume fraction resulting in low thermal conductivity and specific heat capacity and high the thermal diffusivity of foamed concrete with 600 and 1800 kg/m3 density compared to the control mix while the optimum amount of mesocarp fibre only limit up to 30% by volume fraction for 1200 kg/m3 density compared to control mix. The results demonstrated a very high correlation between thermal conductivity, thermal diffusivity and specific heat capacity which R2 value more than 90%.

scholarly journals On the Use of Thermal Properties for Characterizing Dimension Stones

2013 ◽  
Vol 548 ◽  
pp. 231-238 ◽  
Author(s):  
Paulo Amaral ◽  
António Correia ◽  
Luís Lopes ◽  
Paula Rebola ◽  
António Pinho ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Heat Production ◽  
Civil Engineering ◽  
Chemical Properties ◽  
Usual Practice

The use of dimension stones in architecture and civil engineering implies the knowledge of several mechanical, physical, and chemical properties. Even though it has been usual practice to measure physical and mechanical properties of dimension stones the same is not true for thermal properties such as thermal conductivity, thermal diffusivity, specific heat capacity, and heat production. These properties are particularly important when processes related with heating and cooling of buildings must be considered. Thermal conductivity, thermal diffusivity, and specific heat capacity are related with the way thermal energy is transmitted and accumulated in stones; heat production has to do with the amount of radioactive elements in the rocks and so with the environmental impact of radioactivity and public health problems. It is important to start to measure on a routine basis those four thermal properties in rocks and, in particular, in dimension rocks so that their application can be improved and optimized. With this is mind three sets of different rock types (granites, limestones, and marbles) were collected to measure the thermal conductivity, the thermal diffusivity, and the specific heat capacity with the objective of characterizing them in terms of those properties. Since the same set of rocks has also been studied for other physical properties, a correlation amongst all the measured properties is attempted. For each rock type several samples were used to measure the thermal conductivity, the thermal diffusivity, and the specific heat capacity, and average values were obtained and are presented. As an example, for granites the thermal conductivity varies between 2.87 and 3.75 W/mK; for limestones varies between 2.82 and 3.17 W/mK; and for marbles varies between 2.86 and 3.02 W/mK. It is hoped that measuring thermal properties on dimension stones will help to better adequate them to their use in civil engineering as well as to adequate their use in terms of a CE product.

scholarly journals Effect of cooking time on the physical, chemical and thermal properties of acha seeds

2017 ◽  
Vol 6 (2) ◽  
Author(s):  
Akeem O. Raji ◽  
Hajarat O. Nassam ◽  
Tawakalitu E. Aruna ◽  
Monsurat O. Raji ◽  
Maimuna Sani
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Aspect Ratio ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Cooking Time ◽  
Crude Fibre ◽  
Cereal Grain

Acha is a less utilized cereal grain in Africa. Scaling up of the processing technology of acha seeds is desirable if accurate information on effect of processing on its properties is available. This study investigated the effect of cooking duration on the chemical and physical properties of acha seeds. Cooking times (2.5, 5, 7.5 and 10 minutes) at 100oC were used. The volume, length, breadth, thickness, porosity, density, sphericity, aspect ratio, specific heat capacity, thermal conductivity, thermal diffusivity, moisture, protein, fat, ash, crude fibre and carbohydrate were determined using standard methods. Data were analysed using ANOVA at p = 0.05. The results obtained revealed that varietal difference had a significant effect on volume, length, breadth, thickness, true density, bulk density, porosity, sphericity and aspect ratio. The moisture content, ash, protein, crude fibre, fat, carbohydrate, specific heat capacity, thermal conductivity and thermal diffusivity varied from 8.80 - 56.17 %, 0.32 - 1.87%, 1.92 - 11.50%, 0.29 - 1.58%, 0.32 - 2.81%, 40.94 - 76.26%, 1.66 -2.97 kJkg-1K-1, 0.26 -0.43 Wm-1K-1 and 0.85 x 10-7 - 1.17 x 10-7 ms-2 respectively, as significantly influenced by cooking time. Cooking for 7.5 minutes was appropriate using the moisture uptakes and thermal properties as criteria. 

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.

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.

scholarly journals Thermal Properties of New Developed Nigerian Illa and Ekpoma Rice Flour Varieties as Effected with Moisture Content

2021 ◽  
Vol 2 (2) ◽  
pp. 460-471
Author(s):  
Ide PATRICK EJIKE ◽  
Ikoko OMENAOGOR
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Moisture Content ◽  
Specific Heat ◽  
Bulk Density ◽  
Specific Heat Capacity ◽  
Rice Flour ◽  
Thermal Parameters

Thermal parameters of food flour moisture content and temperature give an insight in the development and prediction of models that meet the needs of process design models, it also determine the thermal load of a particular product during handling. The bulk density (ρ), thermal conductivity (k), specific-heat capacity (Cp) and diffusivity (α) of Illa and Ekpoma rice flour were studied at varied (MC) moisture content (%) level. The results showed significance in thermal properties values at the different MC levels. The MC increased from 10.56 to 18.50%, increased the specific heat capacity (Cp) from 5.72 to 48.61kJ kg-1 °C-1 and 6.84 to 29.41 kJ kg-1 °C-1 for Illa and Ekpoma rice variety respectively and thermal conductivity(k) from 0.03 to 1.56 W/m0C and 0.03 to 0.38 W m-1 °C-1 for Illa and Ekpoma rice flour samples. Thermal diffusivity(α) and bulk density (ρ) of the processed Illa and Ekpoma rice flour samples decreased across the MC range of 10.56 to 18.50% (d.b). Thermal diffusivity(α) decreased from 4.38 to 1.25 x 10-4 m2 s-1 and 3.42 to 1.30 x 10-4 m2 s-1 for Illa and Ekpoma rice flour respectively while the values of bulk density (ρ) decreased from 697.72 to 676.34 kg m-3 and 687.49 to 664.26 kg m-3 for Illa and Ekpoma rice flour respectively.The developed model equations can be applied in estimation of thermal parameters of rice flour. Finally, Ekpoma and Illa rice flour sample displayed good thermal characteristics and it can be used as an alternative to imported wheat flour.

ASSESSMENT OF THERMAL CONDUCTIVITY, THERMAL DIFFUSIVITY AND SPECIFIC HEAT CAPACITY OF LIGHTWEIGHT AGGREGATE FOAMED CONCRETE

2016 ◽  
Vol 78 (5) ◽  
Author(s):  
Md Azree Othuman Mydin
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Diffusivity ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Volume Percentage ◽  
Foamed Concrete ◽  
Test Result

This paper focuses on experimental study to investigate the thermal conductivity, thermal diffusivity and specific heat capacity of lightweight aggregate foamed concrete. All the specimens used were tested at 1250 kg/m3 of concrete density. The mix design proportion used for cement, sand and water ratio was 1: 2.67: 0.50. The artificial lightweight aggregate were used as additives by volume percentage of 10%, 13% and 17% based on specific density of artificial lightweight aggregate. Thermal test result shows that thermal conductivity value has fulfill the requirement for semi structure with thermal insulation characteristic which is below than 0.75W/mK and the specimen highest value is 0.66 W/mK. The rate for thermal diffusivity shows that high percentages of lightweight aggregate will reduce the thermal diffusivity. Specific heat capacity test show that the reading was higher when the percentage of lightweight aggregate is higher in lightweight concrete. This is due to the existence of moisture in the lightweight aggregate. 

scholarly journals Effect of Iron Ore Tailings Particle Sizes on the Thermal Properties of Epoxy and Polypropylene Matrix Composites

2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Johnson O Oyebode ◽  
Vivian N Mbagwu ◽  
Modupe A Onitiri ◽  
Olayinka O Adewumi
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Specific Heat ◽  
Matrix Composite ◽  
Specific Heat Capacity ◽  
Iron Ore ◽  
Thermal Resistivity ◽  
Iron Ore Tailings

Thermal properties of materials such as plastic matrix composite is one of the important parameters for determining their behaviour and relevant applications. This present work focuses on determining the thermal behaviour of epoxy and polypropylene (PP) matrix composite reinforced with iron ore tailings (IOT) particulates of sizes 150 µm, 212 µm and 300 µm at various loadings of 5%, 10%, 15%, 20%, 25%, and 30%. The thermal behaviour of the developed composites was investigated experimentally using a KD2 pro thermal analyser. The results obtained from the experiment showed that increasing filler loading in epoxy leads to increased specific heat capacity and thermal resistivity. The maximum values recorded for the thermal resistivity and specific heat capacity were 0. 592°C.m/W and 2.352 J/kgK respectively. Thermal conductivity and thermal diffusivity of values 0.168W/mK and 0.089 mm²/s respectively were the lowest obtained for the epoxy matrix composite. It was also observed that addition of IOT in PP had significant effect on the thermal properties of the PP composite. Thermal conductivity and thermal diffusivity were found to increase with increased particle loading compared to the pure PP sample; the highest value being 2.235 W/mK and 5.51 mm²/s for thermal conductivity and thermal diffusivity respectively while low values of 0.05 Cm/W and 0.371 J/kgK was recorded for thermal resistivity and specific heat capacity. The presence of iron ore tailings reduces the thermal conductivity and diffusivity in epoxy but increases the conductivity and diffusivity in polypropylene. Keywords— Composite, Epoxy, IOT, Polypropylene, Composite, Thermal Conductivity

Determination of the Thermal Properties of a PCB by Coupled Numerical and Experimental Approach

2020 ◽  
Author(s):  
Yener Usul ◽  
Mustafa Özçatalbaş
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Properties ◽  
Numerical Analysis ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Thermal Analyses ◽  
Analysis Model ◽  
Linear Temperature ◽  
Coefficient Of Thermal Conductivity

Abstract Increasing demand for usage of electronics intensely in narrow enclosures necessitates accurate thermal analyses to be performed. Conduction based FEM (Finite Element Method) is a common and practical way to examine the thermal behavior of an electronic system. First step to perform a numerical analysis for any system is to set up the correct analysis model. In this paper, a method for obtaining the coefficient of thermal conductivity and specific heat capacity of a PCB which has generally a complex composite layup structure composed of conductive layers, and dielectric layers. In the study, above mentioned properties are obtained performing a simple nondestructive experiment and a numerical analysis. In the method, a small portion of PCB is sandwiched from one side at certain pressure by jaws. A couple of linear temperature profiles are applied to the jaws successively. Unknown values are tuned in the analysis model until the results of FEM analysis and experiment match. The values for the coefficient of thermal conductivity and specific heat capacity which the experiment and numerical analysis results match can be said to be the actual values. From this point on, the PCB whose thermal properties are determined can be analyzed numerically for any desired geometry and boundary condition.

scholarly journals Comparative study of thermal transport in Zea mays straw and Zea mays heartwood (cork) boards

2010 ◽  
Vol 14 (1) ◽  
pp. 31-38 ◽  
Author(s):  
Sunday Etuk ◽  
Louis Akpabio ◽  
Ita Akpan
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Zea Mays ◽  
Thermal Diffusivity ◽  
Comparative Study ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Thermal Transport ◽  
Insulation Material ◽  
Thermal Absorptivity

Thermal conductivity values at the temperature of 301-303K have been measured for Zea mays straw board as well as Zea mays heartwood (cork) board. Comparative study of the thermal conductivity values of the boards reveal that Zea mays heartwood board has a lower thermal conductivity value to that of the straw board. The study also shows that the straw board is denser than the heartwood board. Specific heat capacity value is less in value for the heartwood board than the straw board. These parameters also affect the thermal diffusivity as well as thermal absorptivity values for the two types of boards. The result favours the two boards as thermal insulators for thermal envelop but with heartwood board as a preferred insulation material than the straw board.

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