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In this paper, we analyze the properties of heavy quarkonia in a curved space-time with conical geometry induced by a topological defect, namely a cosmic string. The particles moving within the latter space are under the influence of an extended version of the Cornell potential. Assuming that the cosmic string space-time is torsion free, the full spectrum of each particle is obtained by solving the Schrodinger equation using the extended Nikiforov-Uvarov method; the wave functions and the radial probability densities of charmonium and bottomonium mesons are derived using the bi-confluent Heun functions. It it observed that the presence of the topological defect, produces a splitting between nP and nD states. The latter states are separated into 2l + 1 components, implying that the gravitational field of a topological defect acts on energy levels like in a way similar to the Zeeman effect due to the magnetic field. However, inthe limit α → 1, which correspond to the usual flat Minkowski space-time, we recover the classical mass spectrum of heavy quarkonia for the extended Cornell potential. The numerical results obtained in this study are overall found in good agreement with experimental data and other relevant theoretical works.Thus, to illustrate the effect of the topological defect graphically, mass spectra, wave functions and radial probability densities are plotted for P−states at different values of α. It is found that, at large values of the quantum number n, the mass spectra of heavy quarkonia exhibit saturation effect governed by the topological parameter. PACS numbers: 21.60.Fw, 21.10.Re, 70.25.+k, 04.10.Mn

X-ray absorption spectroscopy (XAS) was used to characterize the volcanic ash (VA) materials as a low-cost and natural environmental adsorbent for the sorption of Cr(VI). The batch adsorption method was employed to synthesize the sample of chromium(VI) sorbed by VA. The results showed that the Cr-VA material is in the chromium oxidation state(III) and can be described as a composition of Cr2O3 (47.9%), FeCr2O7 (45.2%), and Na2Cr2O7 (6.9%). The promotion of the 1s Cr core electron implies the electronic transitions 1𝑠→3𝑑(𝑡2𝑔) and 1𝑠→3𝑑(𝑒𝑔). The first and second shells in the Cr-VA material were coordinated to the oxygen and chromium atoms in a distorted geometrical arrangement. The adsorption mechanism was associated with the chemical reduction of Cr(VI) to Cr(III) via an ion-exchange process. The XAS technique significantly contributes to the characterization of environmental VA, which can be proposed as an economical and alternative adsorbent for the sorption of Cr from contaminated wastewater.

The present work reports indoor Radon-222 activity concentration measurements, external gamma dose rate measurements, and assessment of cancer risk in the different dwellings in Ebolowa town, south...

The present work was aimed at measuring indoor radon activity concentrations in dwellings in Mvangan locality, South Cameroon, in order to assess the extent of measures that may be necessary for controlling public indoor radon exposure in this area. Measurements were carried out using passive solid-state nuclear track detectors (RADONAVA Inc., RadTrak2, Sweden) following ISO 11665-4 standard. Radon concentration ranged between 36 ± 20 and 150 ± 30 Bq m−3 with arithmetic and geometric means values of 64 ± 25 and 60 ± 1 Bq m−3, respectively. These mean values were greater than worldwide values presented by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), which are, respectively, 40 and 30 Bq m−3. 96% of dwellings that have radon concentrations below the World Health Organization (WHO) reference level of 100 Bq m−3, whereas 4% of dwellings have radon concentrations higher than this level but lower than 300 Bq m−3, the International Commission on Radiological Protection (ICRP) reference level. Annual effective doses due to indoor radon ranged between 0.7 and 2.8 mSv y−1 with an arithmetic mean value of 1.2 ± 0.5 mSv y−1. These values were below the lower limit of the ICRP-recommended action level interval 3–10 mSv y−1. It has been observed that annual effective dose received by residents in cement bricks dwellings were not significantly different (P-value = 0.565) than those received by residents in mud dwellings in Mvangan locality. The mean number of persons expected to be diagnosed with or die from cancer (solid cancers and leukemia) were 162 ± 48 (61 ± 25 for males and 101 ± 41 for females) and 82 ± 24 (33 ± 13 for males and 49 ± 20 for females), respectively. The results obtained in this study prove that the populations of Mvangan locality are exposed to a relatively low potential risk of cancer incidence and mortality.

Technical performances of two optically stimulated luminescence readers including, a microStar reader and an Auto 200 reader both manufactured by Landauer, Inc. were studied by the National Radiation Protection Agency Dosimetry Laboratory using manufacturer and International Electrotechnical Commission requirements. The two reader tools demonstrated satisfactory results as they met all the requirements. The two readers showed similar performance for the overall uncertainty and the Coefficient of Variation tests. The microStar reader showed better performances for the linearity and quality control tests, whereas the Auto 200 reader has a lower limit of detection. Moreover, an average shift of 0.08 mSv exists when measuring the doses with the two readers.

The aim of this paper is to determine the behavior and statistical properties of non-relativistic heavy quarkonia interacting with the extended Cornel potential within a space-time generated by a cosmic-string. We extend the cornel potential by adding the inverse square potential plus the quadratic potential. We have calculated the energy eigenvalues and the corresponding eigenstates using the extended Nikiforov-Uvarov (NU) method. Then the thermodynamic properties like partition function, entropy, free energy, mean energy and specific heat capacity are calculated within the space-time of a cosmic-string. In the next step, we investigate the influence of the cosmic-string parameter on quantum states of heavy quarkonia and their statistical properties.

In the present investigation, natural radioactivity in soil samples from the bauxite ore deposit in FONGO TONGO municipality of Menoua Division, Western Cameroon was assessed using gamma spectrometry. Priory analysis, the detector was calibrated for both energy and efficiency using standard sources. The investigated soil samples of NDIFONDA and APOUH were randomly collected. The observed specific activities of primordial radionuclides in soil from both study areas were comparably higher than the reference values of UNSCEAR, however varied within the exemption levels recommended in the IAEA basics safety standards. The observed average values of radium equivalent activity were 299.58 Bq/kg in NDIFONDA and 425.86 Bq/kg in APOUH. The observe value in APOUH were relatively higher than the recommended save value by ICRP while that of NDIFONDA were lower. Because majority of the houses in the study site are made of brick concrete, radiological health hazard parameters (air-absorbed dose rate (D) and total annual effective dose (ET)) were estimated to evaluate public exposure to natural radiation from soil. The observed values for D and ET were relatively higher than the recommended value of UNSCEAR (143 and 0.48 mSv/year, respectively) in both sites. In addition, the calculated values of excess lifetime cancer risk were slightly higher than the worldwide averages. Finding of this study revealed that long-term exposure to natural radiation in the study area might contribute to some health disease. Therefore, further studies need to be carried out to assess long-term exposure risk to radiation priory exploration of the mine.