Description
TABLE OF CONTENTS
Title Page
i
Declaration
ii
Certification
iii
Dedication
iv
Acknowledgement
v
Table of Content
vii
List of figures
x
List of tables
xii
Abstract
xiii
1.0 INTRODUCTION
1
1.1 Background of the study
1
1.2 Statement of the problem
2
1.3 Aims and objectives
3
1.3.1 Aim of the study
3
1.3.2 Specific objectives of the study
3
1.4 Significance of the study
3
1.5 Scope and limitation
4
2.0 LITERATURE REVIEW
5
2.1 Fundamentals of the studies
5
2.1.1 Radiation
5
2.1.2 Properties of Radiation
7
2.1.3 Sources of Radiation
9
2.1.4 Types of Radiation
10 2.2 Ionizing Radiation
14
2.2.1 Directly ionizing
15
2.2.2 Indirectly ionizing
16
2.2.3 Non-Ionizing Radiation
16
2.3 Black surface
17
2.4 Cavity with a hole
18
2.5 Kirchhoff’s perfect black surface
18
2.6 Silvery surface
19
2.7 Temperature
19
2.8 Review of related past works
20
3.0 MATERIALS AND METHOD
31
3.1 Materials
31
3.2.1 Basic Theory of Black Body
32
3.2.2 Ortogonal Geometry
34
3.2.3 Spherical Geometry
37
3.2.4 Distribution of temperature around the sources of heat
39
3.3 Methods of solutions
40
4.0 RESULTS AND DISCUSSIONS
42
4.1 Results
41
4.2 Discussions
50
5.0 CONCLUSIONS AND RECOMMENDATIONS
52
5.1 Conclusion
52
5.2 Recommendation
53
References
54
LIST OF FIGURES
Figure 1: Comparison between the Rayleigh and Jean’s
calculations (U RJ ) and the measured energy density
(U EXP ) 33
11
Figure 2: Orthogonal Geometry setup
35
Figure 3: Definition of solid angles on surfaces
36
Figure 4: Two concentric Glass Sphere
38
Figure 5: Heat sources from Slab (a) configured Slab, (b)
Elemental Slab
39
Figure 6: Absorption of Radiation by Black and Shiny surfaces
40
Figure 7: Experimental and Calculated Temperature Distribution
for Slab with Distributed heat sources
42
Figure 8: Temperature-Time graph of Blackened Foil and Silvery
Foil
43
Figure 9: Temperature-Time graph of Black coal tar and Thick
shiny Milk
44
Figure 10: Temperature-Time graph of Black liquor soap shiny
water milk
45
Figure 11: Temperature-Time graph of Black coal tar aluminium
foil and Black liquor soap
46
Figure 12: Temperature-Time graph of Watery shiny milk, Thick
shiny milk And Silvery aluminium foil.
47
Figure 13: Temperature-Time graph of Black coal tar, Black
aluminium Foil, Black liquor soap, Shiny Watery milk, Thick shiny
milk and Silvery aluminium foil
48
12
LIST OF TABLE
Table 1: The absorption temperature of radiation by several
black and silvery surfaces with time.
49
ABSRACT
Absorption of radiation by black and silvery surfaces was carried
out using several materials sample of black and silvery
surfaces/liquids. An investigation of our material samples using
temperature sensors reveals that sharp increase in radiation are
more pronounced on black surfaces/liquids than that of silvery
surfaces/liquids. The solutions of the material samples models
were implemented using MALAB software and later exported to
Microsoft word for comparism and analysis. The Geometrical
configuration was greatly altered as the power radiation from rear
surfaces were measured by sensors as different material samples
are taken into account with respect to time. We investigated
theoretically that for an evacuated container, the thermal energy
transfer is solely due to radiation as the vacuum is kept between
two spheres while for a non-evacuated container, an extra heat
transfer occurs due the air’s thermal conductance if the spheres
separation contains air. The results of the rate of absorption of
radiation by the black surface and silvery surfaces for the different
material samples were compared. These results revealed that
black surfaces absorb radiation at greater rate as compared to
silvery surfaces with respect to time. We recommended that other
colors apart from black and silvery be used or added as material in
further research work.
1.0 INTRODUCTION
1.1 Background of study
Absorption of radiation is how matter takes up a photons energy
and so transformed electromagnetic radiation into internal energy of the
absorber (Williams, et al., 2013) a notable effect is to gradually reduced
the intensity of radiation as they propagate through the matter, although
the absorption of radiation does not usually depend on their intensity.
The rate at which a body absorbs radiation depends upon the nature
of the surface, objects that are good emitters are also good absorbers, In
general shiny coloured (eg silvery) and metallic surfaces emit or absorb
radiation energy slowly since they reflects radiation, dark coloured (e.g.
black) surfaces emit or absorb radiation energy more effectively
(Mahmoud et al.,2005).
Radiation partly is the emission or transmission of energy in the
form of waves or particles through Space or a material medium, it occurs
as a result of spontaneous decay of radioisotopes elements which emits
energy (weisstein et al., 2013).
The radiation as wave particles are of two distinct forms which are
the non-ionizing and the ionizing radiation (Richard, 1995). Non-ionizing
radiation are extremely low frequency (ELF) wave which does not
possess enough energy to produce ions and thus has less enough energy
to produce ions and thus has less energy than ionizing radiation and are
not considered to pose a health risk,this radiation are of various types
which include radiation such as visible light, infrared, global positioning
system, radio waves,television stations, micro-waves and sunlight as well
as baby monitors, cordless phones and earth's magnetic field (Eisenbud,
et al., 1997). Ionizing radiation are electrically charged molecules and
atoms which are called ions, capable of knocking electrons out of their
orbits around atoms, upsetting the election/proton balance and giving the
atom a positive charge. This radiation includes the radiation that comes
from both natural and artificial (man-made) radiation and radioactive
such as alpha, beta, gamma and neutron radiations which are considered
hazardous to health, (Erik, et al., 2010).
1.2 Statement of the problem
Ionize radiation can travel through a vacuum when the ionized
radiation hits an object. Some of the energy is absorbed making the object
temperature to increase and some are reflected making the object
temperature to reduce and the rate at which a surface absorbed or
reflected radiation is largely determined by the colour of the object
surface and it greatly affect the temperature of an object. It is against this
backdrop that this study seeks to measure and determine the absorption of
radiation by a black surface and silvery surface.
1.3. Aims and objectives
1.3.1. General objectives of the study
The aim of this research is to investigate the absorption of radiation
by some selected samples of black surface and silvery surface, based on
temperature difference.
1.3.2. Specific objectives of study
The study intends to achieved the following objectives
i. To measure the rate of absorption of radiation by a black surface
and silvery surface.
ii. To compare the rate of absorption of radiation by the black surface
and silvery surface for different materials.
1.4. Significance of the study
The absorption of radiation by a black body surface and a silvery
surface are undoubtedly one of the most significant aspects that
determined the rate of absorption and reflection of temperature, this study
is very significant as it hope to reveal that dull black surfaces absorb
infrared radiation faster as compared to shiny white surfaces which will
be very useful to fashion designers, industrial physicist, meteorologists,
policy makers etc in decision making. Also this study will contribute to
existing knowledge and also serves as reference materials for researchers
on black/silvery surfaces with respect to temperature changes.
1.5. Scope and limitations
The extent of this research is to measure and compared the rate of
absorption of radiation by different surfaces, with respect to temperature
and time using the black surface and silvery surface.