scholarly journals Moisture content modelling of thermal properties of persimmon (cv. ‘Kaki’) 

2017 ◽  
Vol 63 (No. 2) ◽  
pp. 71-78
Author(s):  
Akbari Somaye ◽  
Chayjan Reza Amiri
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Moisture Content ◽  
Property Values ◽  
Regression Equations ◽  
Line Heat Source ◽  
Significant Regression ◽  
Temperature Levels ◽  
Increasing Temperature

Persimmon is one of the tasty and sweet fruits with short shelf life. Thermal conductivity, thermal diffusivity and specific heat are necessary for storage, drying, packaging and designing of distillation machines. In this research, thermal conductivity and thermal diffusivity of persimmon were calculated using the line-heat source probe and Dickerson method. The experiments were conducted at four temperature levels of 40, 50, 60 and 70°C, and four moisture content levels of 37.77, 56.49, 70.47 and 88.42 (%, w.b). Results showed that the thermal conductivity of persimmon was improved by increasing temperature and moisture content of the samples. The effects of moisture content and temperature on thermal properties were highly significant. Regression equations were established which can be used to estimate thermal property values at different moisture content levels.

scholarly journals Moisture dependent thermal properties of selected vegetables in Akwa Ibom State, Nigeria

2019 ◽  
Vol 65 (No. 2) ◽  
pp. 56-62
Author(s):  
Olugbenga Abiola Fakayode ◽  
Olayemi Olubunmi Ojoawo
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Linear Regression ◽  
Moisture Content ◽  
Specific Heat ◽  
Regression Equations ◽  
Content Variation

The thermal properties of some selected vegetables in Akwa Ibom State, Nigeria were investigated. The specific heat, thermal conductivity and thermal diffusivity for the five selected vegetables (Afang, Nkong, Atama, Editan and Nton) were determined and the moisture content variation was investigated. The specific heat values ranged from 2,348–4,580 J·kg<sup>–1</sup>·K<sup>–1</sup>, while the thermal conductivity values ranged from 0.00368–0.489 and the thermal diffusivity values ranged from 1.03 × 10<sup>–7</sup>–1.99 × 10<sup>–7</sup> m<sup>2</sup>·s<sup>–1</sup>. Nton had the highest specific heat and thermal conductivity, while Editan had the highest diffusivity. An increase in the moisture content increased the specific heat, thermal conductivity and diffusivity of the vegetables and the relationships were found to be linear. Regression equations for the thermal properties were established as a function of the product’s moisture content with the experimental data from this study. The thermal properties of the vegetables varied linearly with the moisture content and there were significant differences in the thermal properties of the selected vegetables.

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.

Thermal Properties of Carbon and Graphite Foams

2012 ◽  
Author(s):  
Melanie Patrick ◽  
Amber Vital ◽  
Darian Bridges ◽  
Messiha Saad
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Specific Heat ◽  
Critical Role ◽  
Flash Method ◽  
Petroleum Pitch ◽  
Energy Storage Devices ◽  
Carbon And Graphite ◽  
Temperature Levels

Thermal properties such as specific heat, thermal diffusivity, and thermal conductivity of carbon and graphite foams 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. Thermal conductivity is the property that determines the working temperature levels of the material; it plays a critical role in the performance of materials in high temperature applications and it is an important parameter in problems involving heat transfer and thermal structures. The objective of this paper is to develop a thermal properties data base for carbon and graphite foams. Carbon foams are commercially produced from urethane, petroleum pitch-based and coal-based processes, and they typically have large pores (> 350 μm) and low density (< 1.0 g/cm3). Petroleum pitch-base and coal-base carbon/graphite foams can be tailored to be thermally conductive or thermally insulating. The thermophysical properties of carbon and graphite foams have been investigated using experimental methods. The flash method was used to measure the thermal diffusivity of the foams; this method is based on America Society for Testing and Materials standard (ASTM E1461). In addition, the Differential Scanning Calorimeter was used in accordance with the ASTM E1269 standard to measure the specific heat. The measured thermal diffusivity, specific heat, and density data were used to compute the thermal conductivity of the foams.

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.

3D Examination of the Thermal Properties of Carbon-Carbon Composites

2014 ◽  
Author(s):  
Melanie Patrick ◽  
Messiha Saad
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
High Temperature ◽  
Thermal Diffusivity ◽  
Specific Heat ◽  
Thermal Characterization ◽  
Flash Method ◽  
Carbon Composites ◽  
Scanning Calorimetry ◽  
Temperature Levels

Thermal characterization of composites is essential for their proper assignment to a specific application. Specific heat, thermal diffusivity, and thermal conductivity of carbon-carbon composites are essential in the engineering design process and in the analysis of aerospace vehicles, space systems and other high temperature thermal systems. Specifically, thermal conductivity determines the working temperature levels of a material and is influential in its performance in high temperature applications. There is insufficient thermal property data for carbon-carbon composites over a range of temperatures. The purpose of this research is to develop a thermal properties database for carbon-carbon composites that will contain in-plane (i-p) and through-the-thickness (t-t-t) thermal data at different temperatures as well as display the effects of graphitization on the composite material. The carbon-carbon composites tested were fabricated by the Resin Transfer Molding (RTM) technique, utilizing T300 2-D carbon fabric and Primaset PT-30 cyanate ester resin. Experimental methods were employed to measure the thermal properties. Following the ASTM standard E-1461, the flash method enabled the direct measurement of thermal diffusivity. Additionally, differential scanning calorimetry was performed in accordance with the ASTM E-1269 standard to measure the specific heat. The measured thermal diffusivity, specific heat, and density data were used to compute the thermal conductivity of the carbon-carbon composites. The measured through-the-thickness thermal conductivity values of all the materials tested range from 1.0 to 17 W/m·K, while in-plane values range from 3.8 to 4.6 W/m·K due to the effect of fiber orientation. Additionally, the graphitized samples exhibit a higher thermal conductivity because of the nature of the ordered graphite structure.

scholarly journals Determination of Some Selected Thermal Properties of Pumpkin Seeds (Cucurbita pepo)

2021 ◽  
Vol 25 (4) ◽  
pp. 599-604
Author(s):  
M.O. Sunmonu ◽  
M.M. Odewole ◽  
O.A. Adeyinka ◽  
M.S. Sanusi ◽  
S.O. Musa
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Moisture Content ◽  
Specific Heat ◽  
Average Moisture Content ◽  
Pumpkin Seed ◽  
C Value ◽  
Pumpkin Seeds

In this study, some selected thermal properties (specific heat, thermal conductivity and thermal diffusivity) in the moisture content range of 5.0-5.6% or green and 4.80 – 5.20% for white varieties of pumpkin seeds were determined. The specific heat was measured using mixture method while the thermal conductivity was measured by transient technique using the heat line source. The green pumpkin seed has average moisture content of 5.2% higher than moisture content of white pumpkin seed of average 4.8%. The average specific heat values of green pumpkin seed are 6.171kJ/kgK and white pumpkin seed 4.327kJ/kgK. The thermal conductivity values for white pumpkin seed ranged from 0.074 to 0.288 W/m°C while that for green pumpkin seed ranged from 0.079 to 0.433 W/m°C. The thermal diffusivity values for green pumpkin ranged from 0.0011 to 0.06 m2/s while that for white pumpkin seed ranged from 0.01 to 0.06 m2/s. It was concluded that the higher the moisture content (5.2%) the higher the value of specific heat of seed (6.171kJ/kgK). It can also be concluded that the thermal conductivity (0.079 to 0.433 W/m°C) value is higher with high moisture content (5.2%).

Thermal Characterization of Carbon-Carbon Composites

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.

Experimental Study on Thermal Properties of Hollow Sphere Structures

2021 ◽  
Vol 407 ◽  
pp. 185-191
Author(s):  
Josef Tomas ◽  
Andreas Öchsner ◽  
Markus Merkel
Keyword(s):  
Thermal Conductivity ◽  
Experimental Study ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Specific Heat ◽  
Hollow Sphere ◽  
Plane Source ◽  
Source Method ◽  
Transient Plane Source ◽  
Transient Plane Source Method

Experimental analyses are performed to determine thermal conductivity, thermal diffusivity and volumetric specific heat with transient plane source method on hollow sphere structures. Single-sided testing is used on different samples and different surfaces. Results dependency on the surface is observed.

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