In this study, we explored a new method of cloud detection called the Blue-Green (B-G) Color Difference, which is adapted from the widely used Red-Blue (R-B) Color Difference. The objective of this study was to test the effectiveness of these two methods in detecting daytime clouds. Three all-sky images were selected from a database system at PERMATApintar Observatory. Each selected all-sky image represented different sky conditions, namely clear, partially cloudy and overcast. Both methods were applied to all three images and compared in terms of cloud coverage detection. Our analysis revealed that both color difference methods were able to detect a thick cloud efficiently. However, the B-G was able to detect thin clouds better compared to the R-B method, resulting in a higher and more accurate cloud coverage detection.

No abstract

The attenuation coefficients of cosmic-ray muons through metal plates were theoretically determined. Three methods (A, B, and C) were proposed by the researchers using the experimental data of count rate which was obtained from the detection of cosmic-ray muons through metal plates of different thicknesses. Method A was applied to Pb, Cu, Zn, and Al, whereas Methods B and C were applied to Pb only. The proposed A and B methods were based on ignoring the detected count rate produced by the shower of electromagnetic cascades to obtain the attenuation of cosmic-ray muons. The values and the formula of the radiation length of metals were used in Method A to obtain a theoretical formula to measure the cosmic-ray muon attenuation coefficients. The results showed consistent behavior with the atomic number, mass number, and mass density. In Method C, the penetrating muon is assumed to generate many sources of photon-electron cascades at every collision. The result was successful in describing the theoretical count rate behavior and to implicitly determine the muon attenuation.

Muons produced in the atmosphere by cosmic rays are preferred over gamma rays, X-rays and fast protons for the detection of metals in the study of radiography. An alternative method for metals detection involving portable and relatively cheap Geiger-Muller counters are proposed. The objective of this study was to investigate the validity of using a handmade muon telescope with a small solid angle for the detection of muons inside the metals. This experiment was carried out at Universiti Kebangsaan Malaysia, Bangi (101.78º E, 2.92º N and elevation 30 m). Measurement of muons was conducted in the vertical direction using 1 set of muon telescopes (MT) consisting of coaxial Geiger-Muller (GM) counters. Different metals-lead (Pb), zinc (Zn) and aluminium (Al)-were used as absorbers with different thickness to observe its influence on the count rate of muons. The efficiency of the experimental setup was evaluated using statistical methods and by obtaining sufficient number of muon detection events to describe the physics of the muon interaction with the metals. Based on the Rossi curve obtained for each metal, the transition point was estimated as follows: 1.5 cm for Pb, 4.0 cm for Zn, and 9.0 cm for Al. The results showed that the proposed alternative setup was adequate for detecting muons and therefore have the potential to be further developed.

The ability of a muon telescope to detect high dense metal elements was experimentally determined in previous works. Recently, the muon absorption has become one of the most important data in the tomography technique. In the present study, the absorption coefficients of muon at ground level for heavy alloys, namely brass, steel and stainless steel have been successfully recorded. The experiment was performed in Bangi, Malaysia with coordinates of 101.78º E, 2.92º N and elevation of 30 m above sea level. Muon examination was made by muon telescopes contained of two Geiger-Muller detectors. The muon count rate graphs showed an initial increase, followed by a transition depth and then a decrease with the continuous increase of the alloys thickness. The transition points observed were reliable and consistent with the properties of the alloys. The absorption coefficient of brass was higher than the other alloys; therefore, brass could be detected by cosmic ray muons easily. The results confirmed that the larger the mass density of the alloy absorber, the higher the ability to absorb the muon. The attenuation stated by this experiment would be valuable for coming work on muon revealing procedures.