Thermal Properties of Soil Samples from Coastal Sand Landform in Ilaje Local Government Area of Ondo State, Nigeria

4137 | P a g e C o u n c i l f o r I n n o v a t i v e R e s e a r c h J u l y 2 0 1 6 w w w . c i r w o r l d . c o m Thermal Properties of Soil Samples from Coastal Sand Landform in Ilaje Local Government Area of Ondo State, Nigeria 1 Oluyamo, S. S., 2 Famutimi, O. F., Adekoya, M. A. and Aramide, T. M. 1 Department of Physics, Federal University of Technology Akure, P.M.B. 704, Nigeria Email: oluyamos@yahoo.com 2 Department of Physics, Federal University of Technology Akure, P.M.B. 704, Nigeria Email: meetlekanonline@yahoo.com 3 Department of Physics, Edo University Iyamho, Edo State, Nigeria. E-mail: mathewadekoya14@gmail.com 4 Department of Physics, Federal University of Technology Akure, P.M.B. 704, Nigeria Email: temitopearamide2@gmail.com ABSTRACT


INTRODUCTION
The study of soil properties are of great significant in determining its application in agriculture and many engineering activities where heat transfer is involved especially in the soil .The importance of thermal properties in agriculture and other area of sciences and engineering cannot be overemphasized .Thermal conductivities enable engineers to determine the proper soil for road construction, water drilling and may also help farmers to determine the best soil suitable for planting of crops.It is an important attribute when conserving energy building products [1][2][3].Material structure, size, porosity, moisture content, density, presence of defect, temperature and pressure and other factors are the most influenced when determining the thermal properties of a material [4,5].Various researches had been carried out on thermal properties of soil samples without due consideration on the effect of particle sizes of the material samples.This research work focuses on determining the thermal properties of some soil samples and the effect of particle sizes/moisture content on them.The applications of the soil samples in agriculture and building industries will also be examined.

SAMPLE PREPARATION AND EXPERIMENTAL METHOD
Three different soil samples obtained from a Coastal Sand (CS) landform in Ilaje Local Government Area of Ondo State, South Western Nigeria were used in the study.The soil samples were collected at a depth of about 0 -30 cm and Global Positioning System (GPS) were used to determine the location of the samples.The location and sources of soil collection are shown in Table 1.A mechanical test sieve shaker was used to sieve the soil samples into different particle sizes; 300  respectively.The samples were oven-dried at a temperature of 50 0 C for 40 minutes, compressed and turned into circular disc's shape using modified hydraulic press.The samples moisture content was determined using digital moisture meter and kept inside a desiccator to maintain constant moisture.The apparatus used was a modification of the standard Lees' disc method for the measurement of thermal conductivity by the absolute plane parallel plate technique.This utilizes a steam chest to provide a temperature of 100 .However, the equipment used for this research work uses electrical heating without the need of cooling measurement [7].The value for thermal conductivity (  ) of each sample of thickness (d) and radius (r) as given by [7,8] was determined using the relation.
where e is given by 2 2

RESULTS AND DISCUSSION
The results of the thermal conductivities and moisture contents of the samples are presented in Table 2.The values obtained for the thermal conductivity ranged between 0.3444 11 Wm K  -1.8894 11 Wm K  .Significant variation in the thermal conductivity value of the soil was noticed as the particle sizes changed.The thermal conductivity decreases with increase in particle sizes.This could be due to increase in porosity with increase in particle sizes.This is in conformity to previous research.The thermal conductivity increases with increase in moisture content for all the soil samples.It was observed that Coastal Sand CS2 had the highest thermal conductivity values among the samples considered.This could also be due to the soil fine texture and smaller particles which enable it to retain more moisture than other soil samples.Moisture content has great impact on soil thermal conductivity; it serves as bridges between the soil particle sizes.This bridging increases the effective contact area between the particles which increases the heat flow and results in higher thermal conductivity.This assertion had also be noted in earlier researches [9,10,11] .The values of the thermal conductivities of some common building materials are contained in Tables 3.
Comparing the results obtained in this research with thermal conductivity of some commonly used building materials, it was noted that the soil sample in this landform can be utilised for building construction.In addition, the thermal conductivities in the study conform to the range of thermal conductivities of soil required for some specific crops such as maize, cowpea, pineapple, okro and root crops.Hence, appropriate landforms for agricultural and structural purposes can be ascertained through the knowledge of the thermal conductivities of the soil materials.

CONCLUSION
It was established in the study that the thermal conductivity obtained conformed to the thermal conductivities of some commonly used building materials.The research is also of immense importance to engineers, soil scientists and farmers as it would assist in the knowledge of the the type and quality of soil as well as the type of crops that could be suitable for agricultural purposes in such different landforms.
o C on one side of the sample and subsequently cooling measurements in order to calculate the heat flow through the sample I S S N 2 3 4 7 -3487 V o l u m e 1 1 N u m b e r 1 0 J o u r n a l o f A d v a n c e s i n P h y s i c s 4138 | P a g e C o u n c i l f o r I n n o v a t i v e R e s e a r c h J u l y 2016 w w w .c i r w o r l d .c o m [6] and are the exposed surface areas of discs A, B, C and the specimen respectively.and are the temperatures of the discs A, B and C above ambient.
u m e 1 1 N u m b e r 1 0 J o u r n a l o f A d v a n c e s i n P h y s i c s 4139 | P a g e C o u n c i l f o r I n n o v a t i v e R e s e a r c h J u l y 2016 w w w .c i r w o r l d .c o m