Nuclear and Radiation

An impact of floor levels and geological formation on the concentrations of indoor radon and its progeny studied inside 8 hospitals, and for three floor levels: ground, first and second. Locations of the selected hospitals had different geological formation and located in three main governorates: Erbil, Duhok and Sulaymaniya. Nuclear track detector type CR-39 (CR-39NTDs) used to measure track density of alpha particles that emitted from radon and its progeny. During spring season, 72 pair of exposure chambers (open-close chamber) equipped with 144 pieces of CR-39NTDs installed inside 24 rooms for three floors. After 90 day of exposure, exposed detectors etched in 6N NaOH at 70 ?C for 10 h. The highest and lowest radon concentration was in the hospitals of Shaheed Aso (Sulaymaniya city: 71.09±4.32 Bq.m^-3) and  Erbil Teaching ( Erbil city : 48.02±3.77Bq.m^-3) .This depended on the geological formation, type of building material, and the floor level. Therefore, the results showed that the average radon concentration and annual effective dose decreases gradually as the floor level increases. The highest and lowest of annual effective dose was found in ground and second floor, respectively. Thus, according to the annual exposure dose data, the workers are safety in most of the hospitals. More details about the type of building materials of the hospitals are listed in full paper.

Values of dielectric constant ( ), dielectric loss ( ), relaxation time ( p), conductivity (?p) and moisture content of pulverized samples of Fenugreek were measured for different packing densities at 9.85 GHz microwave frequency and at different temperature ( 20?C, 35?C and 50?C). Experimental results on powders of different packing fractions (?r) were used to obtain transformation to 100% solid bulk using correlation formulae of Landau-Lifshitz-Looyenga and Bottcher. It is found that, there was fair agreement between the calculated values of dielectric parameters and the values obtained experimentally for solid bulk. This shows cohesion in the particles of Trigonellia Foenum-Graecum Linn. powder under investigation.

The epithermal neutron shape factor(?) in the permanent cadmium lined irradiation channel of the Nigeria Research Reactor-1(NIRR-1) was re-evaluated using the four monitor combinations 198Au-99Mo- 97Zr- 95Zr, 198Au- 97Zr- 95Zr- 65Zn, 198Au-60C0- 97Zr- 95Zr and 198Au- 60Co- 97Zr- 95Zr- 99Mo in the monitor set Al-0.1%Au thin foil, Zr and Zn foils, Mo and Co thin wires irradiated for ? determinatiom by the cadmium covered multtimonitor method. The monitor combination 198Au-99Mo- 97Zr- 95Zr was found to give a relatively higher and more reasonable value of ? of -0.101±0.019. Also the value of ? determined using only the three monitor combination 198Au- 97Zr- 95Zr was found to be -0.106±0.014 and is comparable with the ? value for the monitor combination198Au-99Mo- 97Zr- 95Zr. The negative values of ? in both determinations indicate a hardened epithermal neutron spectrum in the cadmium lined irradiation channel.They are comparable with the value of -0.137±0.018 previously obtained. The values of the epithermal neutron flux(?e ) and comparator factor (Fc,Au ) of 4.80±0.04)×109 and (1.38±0.01)×103 respectively using the activity 198Au for the monitor combination198Au-99Mo- 97Zr- 95Zr are comparable with the ?e and Fc,Au values of (4.76 ±0.04)×109 and (1.37±0.05)×103 respectively for only the three monitors 198Au- 97Zr- 95Zr .The ?, ?e and Fc,Au values can be well determined in the cadmium lined irradiation channel of the NIRR-1 using only the Au+Mo+Zr or Au+Zr monitor combinations.

Radon is a naturally occurring colourless, odourless, water-soluble gas produced by the radioactive decay of radium. Chronic exposure to radon is recognized as a health risk. Ingested water with elevated levels of radon can present a risk for developing internal organ cancers. Thirty (30) water samples collected from four different water sources (borehole, pond, hand – dug well and river) in Pwalugu and their environments were analysed using the Gamma Spectrometry System. The radon concentration varied from 29 ± 1.1 to 40 ± 2.1 µBq/L. These values fall below the maximum concentration level, of 0.148 Bq/L proposed by the US EPA. The highest concentration was recorded in borehole samples because of the nature of the geology and because no radon was lost due to aeration. The calculated annual effective dose by ingestion varied between 2.920 × 10-7 and 2.117 × 10-7 Sv/y which is below the recommended value of 1mSv/y.

The effects of exposure from electromagnetic radiations of wireless cellular transmission towers on human health have attracted the attention of many researchers. Different works have revealed the harmful of electromagnetic radiation exposure to human health based on distance from the source and period of exposure. As one stays closer and at a pro-longed period from the transmission sites, the possibility of being affected by the radiation source becomes higher. This work was designed and conducted on the basis of selection of the three major telecommunication companies’ towers in Khartoum state, namely ZAIN, SUDANI and MTN. Generally, the measurements employed showed that bigger amount of radiations were detected right away closer to the tower and remain smaller when the distance from the tower is increased. The level of EMR is not that significant and still safe with reference to the recommendation of world health organization (WHO) and International telecommunication corporation (ITC). Therefore a non adverse obvious effect on the biological system is expected.

This investigation uses Multi Channel Analyser (MCA) coupled with Gamma Ray Spectroscope (GRS) to investigate some common counting statistics used for radiation measurements of a 137Cs gamma source. Few statistical tests involving 25 and 100 trials for data acceptance were applied to study the stability of counting system. The statistical analysis evaluated count data on on four primary criteria; the Ratio Test, Chauvenet’s Criterion, the Chi-square test, and a control chart. The control chart also reflected almost accurate statistical data except for a minor error during few points of the 25 trial test. Fano factor was also evaluated for both trials to ascertain the measure of reliability and signal to noise ratio of the equipment. The results demonstrated that the counting system was fairly accurate, with a few exceptions. The Ratio Test, Chauvenet’s Criterion, and the Chi-square test each, was passed successfully. After evaluating the statistical data, Poisson distribution was created to better analyze the data.

In this work, concentrations of radon indoor were measured at 10 locations in Al-Kufa and Al- Najaf cities, using RAD-7 radon monitoring system of Durridge company USA. Some factors affecting on the radon factor have been studied such as times of day (morning, afternoon and evening) and seasons of year (winter, spring, summer and autumn). This study show that the radon concentration indoor increases at mornings, evenings, decreases at afternoon, also increases in winter and autumn, decreases in spring and summer.

This research was carried out to monitoring natural radioactivity level in rock samples were taken from Northern Nuba Mountain, Dallanj region - South Kordofan State. Gamma ray spectroscopy technique was used to evaluate radioactivity level to establish background radiation level. Measured activity concentrations of radionuclides 226Ra,232Th and 40K ,absorbed dose and annual effective dose were found 23.56±2.11, 29.57±4.33 and 330.58±37.06 Bqkg-1 and 33.34±3.39 nGyh-1 and 40.92±4.16 µSvy-1 , respectively. The obtained data shown that values are far below than reported global data. Estimation of the relative contribution of the 226Ra, 232Th and 40K to the overall absorbed dose in air discovered that the main contribution comes from 232Th 53.57 %.

Pressure dependent exciton binding energy in a Cd0.8Zn0.2Te/ZnTe strained quantum dot is investigated with the geometrical confinement within the single band effective mass approximation. The interband transition energy as functions of dot radius and the hydrostatic pressure is brought out. Computations are carried out using variational formulism. The pressure induced oscillator strength and the nonlinear optical rectification coefficient of an exciton in a Cd0.8Zn0.2Te/ZnTe quantum dot are studied using matrix method. Our results show that the exciton binding energy, interband emission energy and the nonlinear optical rectification coefficient are strongly dependent on the geometrical confinement and the applied hydrostatic pressure values.

The correct theoretical analysis of the generally accepted foundations of theory of photon (quantum) gas are proposed. The principle of the unity of formal logic and of rational dialectics is the correct methodological basis of the analysis. The new results – the correct quantum-statistical foundations – obtained within the framework of the formulated master equation taking into consideration both the quantum states of the radiating molecule and the quantum states of the photon gas in the isolated macroscopic systems “molecule + molecular gas + monochromatic photon gas” are as follows: (a) Planck’s, Einstein’s, and Bose’s works on the theory of photon (quantum) gas contain logical errors; (b) photon (quantum) gas being born by radiating molecule obeys “Gibbs statistics”: equilibrium photon (quantum) gas is described by Gibbs quantum canonical distribution; (c) Planck function (“Bose’s distribution”) is an consequence of Gibbs quantum canonical distribution; (d) Einstein coefficients (i.e. the coefficients of spontaneous emission, induced emission and absorption) are equal to each other.