Thermoluminescence (TL) response of newly synthetic silicon-activated Ca9AlP7O28 nanophosphor doped with different concentrations (0.3–10 mol

Experimental investigations on gamma - rays attenuation parameters and dielectric spectroscopic properties were done on a polymeric mixture with chemical composition (100-x) polyethylene + x basalt, where x = 0, 1, 3, 5, 10, and 20 wt%. Using the melting blending technique,six nanocomposite polymeric samples were prepared. The linear attenuation coefficient mu of each prepared set of samples was measured using a gamma -ray spectrometer including High Purity Germanium detector (HPGe) at energies 662.5, 1173.24, and 1332.51 keV. Based on the measured values of (mu) and sample density, the other effective shielding parameters were calculated. the values of mu showed an increase with increasing the dopant ratios from 0.0 up to 20.0 wt%. In addition, the mu values decreased with the photon's energy. The mu values were found 0.0847 up to 0.1175 cm - 1, 0.0571 up to 0.0855 cm - 1, and 0.0543 up to 0.075 cm- 1 at 662.5, 1173.24, and 1332.51 keV. for B0 up to B20, respectively. The ATR spectroscopy was done on the prepared samples, and a good evidence of adding the filler to the pure polyethylene (HDPE) was obtained. Besides, an enhancement in dielectric constant by insertion of basalt NPs also recorded and can be attributed to the large dielectric constant of basalt compared to pure HDPE.

In this study, new PVC (polyvinyl chloride) polymers doped with different contents of basalt nanoparticles have been prepared. The PVC was mixed with concentrations (0, 5, 10, 15, 20, and 50 wt%) of basalt nanoparticles utilizing the casting method. The samples coded as PB0.0, PB5.0, PB10.0, PB15.0, PB20.0, and PB50.0. The density of the casted samples increased from 1.38 to 2.18 g/cm3 with increasing basalt nanoparticle concentrations. Scanning electron microscope (SEM) of the prepared samples showed a good dispersion with small basalt concentrations in the while some agglomerations were found with the highest basalt concentrations in the mixture. The values of the direct optical energy gap varied from 3.0 to 3.5 eV, while the refractive index values changed from 2.39 to 2.27. The gamma-ray shielding parameters were evaluated using the Phy-X/PSD software program as well as the MCNP - code. The most critical results showed that the linear-attenuation coefficient (& mu;) increased from 14.421 to 23.862 cm � 1 (at 0.015 MeV), and from 0.030 to 0.048 cm - 1 (at 15 MeV) for PB0.0 and PB50.0 samples, respectively. Moreover, the evaluation of other gamma - ray shielding characteristics showed an enhancement with the addition of the basalt nanoparticles. Besides, neutron cross section was also calculated, and results revealed that PB0.0 is 0.086 cm � 1 and PB50.0 is 0.104 cm- 1. Finally, the obtained results concluded that the & gamma; -ray, and neutron shielding capacities were enhanced with the increase in basalt nanocomposites amount in the fabricated composites.

The present work was conducted to characterize the mangrove sediments along the Egyptian Red Sea in terms of elemental composition and to assess the extent of pollution and its sources. A total of 26 samples of mangrove sediments were collected from three different areas: Sharm El Madfea, Sowmaa Mangrove and Abu Fasi. The samples were analyzed using the inductively coupled plasma - mass spectrometry ICP-MS and atomic-emission spectrometry ICP-AES. Mass fractions of a total of 58 major and trace elements were determined in the mangrove samples. Univariate and multivariate statistical analyses were performed to determine the origin of trace and major elements in the mangrove sediments. The normalized values show that the elements above the background can be indicated in descending order as follows: P > Cd > Sr > Ca > U > Se > As > Sn > Cu > Sb > Pb > Mo > Ag. Several pollution indices were also calculated. Principal component analysis revealed three clusters of the studied sediment samples. The analysis of the ratio indicators shows that the origin of the sediments mostly falls near continental island arcs (CIA). The pollution indices show remarkable pollution levels and enriched elements. The data obtained can serve as baseline data for the sediments of the mangrove environment and can be used to study possible changes in the future.

The present work was conducted to determine Th/U ratios in different types of natural rock samples (sedimentary, conglomerate, igneous and sediments) using high-purity germanium detector, solid state nuclear track detectors and inductively coupled plasma mass spectrometers.A thin source approach method for alpha tracks measurements was used.A new method was introduced for forming a thin layer of the rock sample.The track densities were obtained using an optical microscope coupled with a digital camera and spark counter.Even though the measurements were carried out using very different techniques, they showed comparable values of Th/U ratio for most of the rock samples.

The present study was conducted to provide a comprehensive picture of marine sediment characterization in terms of geochemistry and the extent of pollution. A total of 99 surface coastal sediments were collected from coastal areas along with the Egyptian Mediterranean Sea. The samples were analyzed by neutron activation analysis (NAA) and the mass fractions in mg/kg of 39 trace elements were determined. The normalized mass fractions show significant amounts of Cl (26.4%), Sn (12%), Zr (7.3%), Hf (5.9%), Ti (4.7%), Cr (4.2%), Ca (3.4%), Si (3.1%), Sr (2.9%). The mass fractions of the rare earth elements REEs (La, Ce, Nd, Sm, Eu, Tb, Dy, Yb, and Lu) are almost double compared to literature data. Principal component analysis PCA and positive matrix factorization PMF were used to decipher the sources of pollutions. Sediment quality was quantified using different pollution indices such as enrichment factor (EF), modified pollution index (MPI), pollution load index (PLI) and the new approach to calculate total pollution index (TPI). The results of the study recognized four locations with significant pollution, namely the coastal area along Al Manzalah Lake, the Nile River estuaries at Ras Elbar and its western coastal area, at the outlet of Elbrullus Lake, and finally the Abu Qir Bay. The obtained result can serve as a geochemical background of the sediments of the study coastal area, which allows following the quality of marine sediments along with the Egyptian Mediterranean Sea.

The present work was conducted to evaluate the air quality in terms of inorganic pollutants and toxicity impact using two evergreen tree leaves, Eucalyptus globulus Labill (E. globulus) and Ficus microcarpa L.f., Suppl. Pl. 442 (1782) (F. microcarpa) as biomonitors. Thirty tree leaves and an equal number of co-located soil samples from different regions of Egypt (urban Greater Cairo Metropolitan (GC) and rural Menoufia Governorate (MG)) were collected. The concentrations of 34 and 40 elements were determined using instrumental neutron activation analysis (INNA) and atomic absorption spectrometry (AAS) in tree leaves and soils, respectively. Bivariate and multivariate statistical analyses were implemented. The air pollution was assessed using enrichment factor, pollution load index, potential ecological risk, and risk index. In addition, human and ecotoxicity were evaluated based on the ReCiPe method. The mean concentration values of the obtained elements in tree leave in urban Greater Cairo and rural Menoufia Governorate show that the major elements are slightly higher in F. microcarpa than in E. globulus. Likewise, the mean values of elements in soil from GC and MG show no significant difference except for major elements (Fe, Al, Mg, K, Na, and Ti) in MG. The normalized concentrations of tree leave and soil show that the accumulated elements by F. macrocarpa are slightly higher than in E. globulus in GC and MG. While in terms of the investigated area, the concentrations of elements in MG are considerably higher than in GC. Pollution load index (PLI) spatial distribution over investigated areas showed that despite high population density, heavy traffic, and urban pollution, the Cairo samples exhibit significantly lower values as compared to those from Menoufia, which is most likely due to the uncontrolled industrial and domestic waste disposal outside Cairo. Potential ecological risk (PER) was significant for As in soil and for As and Cd in tree species. Human toxicity shows higher values in urban locations. Contrariwise, in the terrestrial ecotoxicity aspect, the rural locations are much higher than in urban ones.

The present review was conducted to highlight the major and trace elemental composition in surface sediments from the Nile River and Egyptian Red Sea coastal areas in terms of provenance, concentrations, pollution indices, and health hazards. Health hazard due to the exposure to selected elements via inhalation, ingestion, and dermal contact was calculated. The samples were subjected to neutron activation analysis. Bivariate and multivariate statistical analysis was employed. Significant amounts of V, Cr, and Zr are observed in Nile sediments. Whereas, considerable concentrations of Br and Ca were found in marine sediments. The concentrations of the other elements are in line with the corresponding values in upper continental crust. The outcomes of the pollution indices show some localized polluted sites (Helwan, Cairo, and Delta) in Nile sediments. Likewise, in Abu Ghusun area in marine ones. Overall, the hazard index of the investigated elements in the Nile and marine sediments for both studied age criteria is higher than the tolerable values (1 × 10-6 - 1 × 10-4).

A comprehensive characterization of the biomonitoring of air pollution assessment using Eucalyptus Globulus and Ficus Nitida plants in Cairo and Minoufia cities in Egypt is given.The concentrations (ppm) of thirtytwo elements were determined in 30 leaf samples by means of the epithermal neutron activation analytical technique.The collected samples were irradiated by epithermal neutrons at REGATA -pulsed reactor IBR-2 in Dubna, Russian Federation.The obtained concentrations of; Na, Mg, Al, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, As, Se, Br, Rb, Sr, Sb, I, Cs, Ba, La, Sm, Tb, Hf, Ta, Au, Th, and U were compared to the reference plant.The analysis of the obtained concentrations revealed that the concentrations at some sites in Menoufia Governorate were significantly higher than those in Cairo, in spite of the intense population, heavy traffic, and vehicle waste disposed in Cairo.The remarkable increase of metals in Menoufia Governorate has occurred most probably due to the uncontrolled disposal of industrial and domestic waste.In addition, the study shows the Ficus Nitida plant responsiveness to metals is higher than Eucalyptus Globulus.

ABSTRACT The activity concentrations of natural 40K, 232Th, and 238U in 89 soil and 84 sediment samples collected over the entire Egyptian Nile River basin including the Nile delta are reported based on the results of epithermal neutron activation analysis. The average activity concentrations of 40K, 232Th, and 238U equal to 15.3 ± 6.6, 15.6 ± 11.1 and 220 ± 31 Bq/kg, respectively, are significantly lower than those reported for the Upper Continental Crust, World Average Sediments as well as World Average Soils, suggesting the presence of a considerable portion of mafic material, most probably originating from the Ethiopian High Plateau. Their average activity concentrations are statistically the same in soil and sediments, indicating that the Nile sediments and soil material are of the same origin. The main goal of this study was not only to estimate the radiological hazards but also to show the influence of sedimentary material transportable by the Blue Nile from the Ethiopian High Plateau. The different hazard indices like the radium equivalent, gamma index, external hazard as well as the internal hazard show a low radiological exposure either on direct contact or if local mud bricks are used in the construction of dwellings.

In this work we present some results of the interaction of high-energy muons with emulsion nuclei. The interaction results in emission of a number of fragments as a consequence of electromagnetic dissociation of the excited target nuclei. This excitation is attributed to absorption of photons by the target nuclei due to the intense electric field of the very fast incident muon particles. The interactions take place at impact parameters that allow ultra-peripheral collisions to take place, leading to giant resonances and hence multifragmentation of emulsion targets. Charge identification, range, energy spectra, angular distribution and topological cross-section of the produced fragments are measured and evaluated.

The distributions of 32 major and trace elements in 72 surface soil and sediment samples collected from the Asyut to Cairo Nile river section were determined by epithermal neutron activation analysis and compared with corresponding data for the Upper Continental Crust, North American Shale Composite, Average Soil and Average Sediment as well as suspended sediments from Congo and Upper Niger Rivers, in order to establish to which extent the Nile sedimentary material can be related to similar material all over the world as well as to local geology. Their relative distributions indicate the presence of detrital material of igneous origin, most probably resulting from weathering of the Ethiopian Highlands and transported by the Blue Nile, the Nile main tributary. The distributions of nickel, zinc, and arsenic contents suggest that the lower part of the Nile and its surroundings including the Nile Delta is not seriously polluted with heavy metals, so that, in spite of a human activity, which lasted four millennia, the Nile River continues to be less affected by any anthropogenic contamination.

Quasiparticle injection devices are considered as one of the candidates for the high temperature superconductor transistors, which can operate at liquid nitrogen temperatures. In these devices the nonequilibrium effects are created by injecting quasiparticle current into a stack of intrinsic Josephson junctions (IJJs). These effects lead to an occurrence of a shift of the condensate chemical potential and a difference in the distribution between the electron-like and the hole-like quasiparticles that causes a charge imbalance. Such effects are observed in many experiments for both bulk and layered superconductors. In this paper, we study non-stationary nonequilibrium charge imbalance effect due to current injection in a stack of IJJs. We investigate the effect of the charge imbalance on the current-voltage characteristic (IVC) and the time dependence of the voltage and the quasiparticle potential in a stack of five IJJs.

Assessment of the environmental impact of El Sadat City, a Cairo satellite, known for its clustered enterprises, on the neighbourhood water supply El Manashi Tawfikia Canal was undertaken through soil analysis. A total of 20 agricultural soil samples were collected along the El Manashi Tawfikia Canal. Neutron activation analysis was implemented to determine heavy metal contents of such elements as As, Ba, Co, Cr, Ni, and Zn. Multivariate statistical analysis was applied to the results obtained. The metal pollution index and enrichment factor were calculated. It was shown that the content of toxic heavy metals in soil samples does not exceed the worldwide-published values, except arsenic which considerably exceeds normalized to the content of the same element in the Upper Continental Crust. The metal pollution index is high compared with the calculated ones for similar soil samples from the Nile Delta, and the enrichment factor varied from moderate to high enrichment (5 < EF > 10).

Detailed numerical simulations of intrinsic Josephson junctions of high-temperature superconductors under external electromagnetic radiation are performed taking into account a charge imbalance effect. We demonstrate that the charge imbalance is responsible for a slope in the Shapiro step in the IV-characteristic. The value of slope increases with a nonequilibrium parameter. Coupling between junctions leads to the distribution of the slope's values along the stack. The nonperiodic boundary conditions shift the Shapiro step from the canonical position determined by V-88 = hf/(2e), where f is a frequency of external radiation. This fact makes the interpretation of the experimentally found Shapiro step shift by the charge imbalance effect ambiguous. Copyright (C) EPLA, 2016

The transparent thermoluminescent aluminum oxide-based glass of 15Al2 O3 -35P2 O5 -25CaO-25Na2 CO3 , abbreviated as APCN (all in mol%) doped with different concentrations of SiO2 from 0.0-500 ppm was prepared using a conventional melt-quenching technique. The TL sensitivities of the prepared glasses were investigated at 3 Gy γ-dose using a 60 Co source and measured at a heating rate 10 C/sec. The highest TL intensity of the material doped with SiO2 was found at a concentration of 500 ppm (APCNSi5 ). Deconvolution of the glow curve from APCNSi5 resulted in four peaks at about 161, 194, 237 and 293 C with a Figure Of Merit (FOM) of 1.28%. The APCNSi5 specimen had the best dosimetric properties when compared with the other samples. Reproducibility, repeatability, dose-response curve and fading effect were checked for peak 3, which appeared at about 237 C. The results displayed that the APCNSi5 glass system was a low-Z material (Zeff  ≈ 10), and had good reproducibility and good repeatability. Peak 3 showed good linearity over a dose range up to 20 Gy (R2  = 0.999) and sublinearity behaviour was found. The signal from APCNSi5 faded by about 11% after 2 days post irradiation, therefore it showed almost no significant loss. Such properties make the newly prepared glasses suitable for and highly recommended for use in γ-dosimeters. Copyright © 2016 John Wiley & Sons, Ltd.

This study reports the characteristic studies for the detection of alpha particles in DAM–ADC nuclear track detector. Several important parameters that control the track formation such as, the bulk etch rate (VB), track etching rate (VT), dependence of VB and VT on etching concentration and temperature have been extensively studied. The activation energy (Eb) of the bulk etching rate for the DAM–ADC sheets has been calculated, the dependence of etching efficiency and sensitivity upon etchant concentrations and temperature has been investigated, registration efficiency of DAM–ADC detector etched at the optimum etching condition has been examined. The detailed studied results presented in this study provide various useful information about the mechanism of track formation in polymers.

A well performance Electrolytic Controlled Etching (ECE) unit has been designed and constructed in our laboratory. Low electric field strength of few volts and a 2 kHz wave signals has been applied across the electrodes that confined the 9 and 12 μm thick PET foils in the ECE unit. PET foils were exposed to fission fragments (FFS) using 252Cf source. The dependence of different measurable parameters such as FFS fluence (Φ), applied voltage (V), etching temperature (T) and etching concentration (C) on both track etch rate (V T) and breakthrough time (T B) have extensively been studied using the FFS-irradiated PET foils. Various empirical relationships connecting the results of the present work have been extracted. Moreover, the constructed ECE technique has proven to be an encouraged time saving method in the development of trusting measurements comparing with others that might involve expensive sophisticated tools.