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In this work, a heterojunction of Al/p-Si/CoPc/Au was fabricated using the thermal evaporation technique by depositing CoPc on the p-Si. Complex impedance spectroscopy was employed to investigate the impedance characteristics and the full band profile measurements of the fabricated heterojunction. Arrhenius fitting of double relaxation operations was utilized to determine the activation energy of the tested device. The studied device gains a negative temperature resistance coefficient as interpreted from the electrical conductivity and Cole–Cole fitting. The lifetimes of the excess minority carriers, the coefficients of carrier diffusion, and the charge carrier mobilities at the interfaces were measured and estimated.

The aim of present work is measuring the natural radioactivity of uranium-238, thorium-232 and potassium-40 in some spice samples that widely use in Iraq. Based on these measurements, the correspon...

In the present work, Particulate Matter (PM) elemental composition and mass size distribution were examined in rural and urban sites at El-Minia governorate, Upper Egypt. Aerosol particles are collected with cascade impactor (Low pressure Berner Type). Seven elements are investigated with atomic absorption spectroscopy technique (Fe, Ca, K, Ba, Cu, Mn and Pb). Five Measurements are performed in each site rural (El-sharyna village) and urban (Maghagha city). During the sampling, meteorological parameters such as temperature and relative humidity were registered by a thermo hygrometer Hi 8564. Abi-modal log normal size distribution corresponding to accumulation and coarse modes are established for elementals and PM. In the present study, the mean aerosols mass concentration (265 ± 16 μg/m3 in urban and 300 ± 17 μg/m3 in rural). These values excess the WHO primary (80 μg/m3) and secondary (60 μg/m3) standards during the four seasons. Also, they excess the annual average of the Egyptian Ambient Air Quality Standard (90 μg/m3). The mass concentrations for elements changed from 0.6 ng/m3 (for Ba) to 109 ng/m3 (for Fe) in the rural site. While in the urban site is ranged from 0.05 ng/m3 (for Ba) to 97 ng/m3 (for Fe). The mean elements mass concentrations are founded Fe (97–109), Ca (0.29–1.6), K (2.6–40.3), Cu (0.39–1.7), Mn (2.97–6.41), Pb (0.39–0.71), and Ba (0.11–0.4) ng/m3 for the urban and rural sites respectively.

In the present work, Thermal oven as a heating technique in chemical etching process has been tested to investigate the track density and compares with a traditional technique water bath (WB). Thermal oven induced chemical etching has been employed in reducing the etching duration. Two solid-state nuclear track detectors (SSNTDs) CR-39 and LR-115 are utilized in this comparison. Detectors are exposed to 226Ra alpha source (5 µ ci). Several pieces of CR-39 and LR-115 detectors were exposed to 226Ra source at three different times of exposure (5, 10 and 15sec). Chemically Etching carry out with NaOH alkaline solution (6.25 N) at 70 °C for CR-39 and (2.5 N) at 60 °C for LR-115. For (5, 10 and 15sec) exposure time, the estimated maximum track densities of CR-39 detector at 90 min for thermal oven compared with 120 min for water bath. LR-115 detector maximum track densities were founded at 40 min compared with 50 min for the water bath technique. Finally, the etching parameters (the diameter of the tracks (D), etching efficiency (ɳ), bulk etching rate (VB), track etching rate (VT), and the sensitivity (V)) were calculated and compared.

In the present work, the influence of plastic deformation on the properties of a 3004 Al-alloy was studied with different techniques. Crystallite size, dislocation density, defect density, micro-strain, and stored dislocation energy are presented and compared for different three techniques. Methodology Many techniques for detecting defects have been developed, such as the positron annihilation lifetime technique (PALT), the positron annihilation Doppler broadening technique (PADBT), and the Vickers hardness test (HV). Implications The positron mean lifetime value of a non-deformed sample is 173±4.8 ps, which increases until the thickness reduction reaches a 10% deformation then saturated at saturation trapping of the positron in defect states with a mean of 221±5 ps. At an S-parameter of 0.3709±0.0031, a W-parameter of 0.5885±0.0057 was obtained at zero deformation: this decreases until saturation at 10% deformation. Findings A good correlation between the three techniques is observed for mean crystallite size. A good correlation was also noted between PALT and PADBT from 0 to 10% thickness reduction. HV has good correlations with PALT and PADBT from 0 to 6% thickness reduction: then a clear difference was found from 6 to 15% thickness reduction. Originality such results confirm the fact that the used technique can effects on the obtained results in some limitations.

In this work, radon excess lung cancer (ELC) was estimated for 14 soil samples from the Babylon cement plant in Iraq. A CR-39 nuclear track detector was used to measure uranium and radon (222Rn) concentrations in the soil samples. The uranium concentration varied from 0.008 to 0.05 ppm, with a mean value of 0.025 ± 0.013 ppm. The radon concentration was found to be between 31 and 92 Bq/m3, with a mean value of 56.72 and a standard division of 17.29. The radon ELC per million persons per year has a mean value of 863 (463.81–12,082.8) and a standard division of 261.65. The annual effective dose, E (mSv/y), ranged from 0.77 to 2.32, with a mean value of 1.44 and a standard division of 0.44.

Background 177Lu and 153Sm are perspective radionuclides in terms of applying to nuclear medicine. High-energy beta particles and the relative half-life of the radionuclide are used to achieve an effective palliative treatment of bone metastases. Materials and methods The absorbed doses in different organs and tissues of 177Lu and 153Sm in ionic form and labeled with EDTMP are determined by IDAC-Dose 2.1 (Internal Dose Assessment by Computer) software and WinAct software which used to calculate cumulative activity. 177Lu and 153Sm are lanthanide radionuclide which actively accumulates in liver and bone when used in ionic form. In the case of labeling with EDTMP, the distribution and elimination of the drug occur according to the kinetics of a carrier, EDTMP. The using of osteotropic (Describing any drug etc. that is attracted to, and targets bone) complex allows creating a large dose in the pathological areas and minimizing damages in healthy organs and tissues. Results The effective dose per administered activity is 0.189 mSv/MBq for 177Lu-ionic form, 0.232 mSv/MBq for 153Sm-ionic form and 0.242 mSv/MBq for 177Lu-EDTMP and 0.139 mSv/MBq for 153sm-EDTMP. Conclusion 177Lu and 153Sm labeled with EDTMP are decreasing the liver dose absorption and increasing the bone surface absorption for more effective treatment and minimize side effects.

Purpose: In recent years, radionuclides like 177Lu have been considered promising material for the creation of therapeutic radiopharmaceuticals. With the therapeutic use of radiopharmaceuticals, th...

Information regarding the number, mass, and specific surface area distributions of aerosols is extremely important for assessments of exposure to radiation due to the intake of radioactive aerosols by inhalation. In this study, these distributions were compared with the activity size distributions for radon decay products. The experiments were conducted in a radon chamber under controlled conditions for the aerosol concentrations and with size distributions in the range from 5 nm to 10 µm. The activity size distributions of the aerosols were measured by using a diffusion battery and two types of cascade impactors. The aerosol concentrations during the experiments were in the range from 2 × 103 to 2.5 × 105 cm–3. The measurements obtained with a diffusion battery demonstrated that at the low aerosol concentration, up to 80% of activity of the radon decay products was connected with aerosol particles with an activity median thermodynamic diameter (AMTD) ~1 nm (unattached fraction). After injecting the aerosols into the experimental chamber, the activity of the unattached fraction decreased to practically zero but we observed the presence of the activity of aerosols with AMTD values ~10–20 nm. After injecting the aerosols, the distribution of the aerosol specific surface area exhibited a bimodal distribution, where the median diameter in the accumulation mode was ~120 nm and the geometric standard deviation (GSD) was 1.3. The median diameter in the coarse mode changed with time due to the deposition of aerosols on the walls of the chamber, where it decreased from 5 µm (GSD = 1.6) at 15 min after injection to 2 µm (GSD = 2.5) at 120 min after injection. The distribution of the aerosol activity measured by the cascade impactor was virtually independent of the time from the moment when the aerosols were injected. The parameters used to assess the activity distribution comprised an activity median aerodynamic diameter (AMAD) ~500–650 nm and GSD = 1.5. Comparisons of the activity distributions with the distributions for the number, mass, and specific surface area showed that the closest correspondence was with the average distribution over the specific surface, whereas there were no exact correspondences with the other distributions.

In this work, the permeability of the radioactive aerosol particles through different types of Petryanov filters is studied. The experiments were performed with standard radon box, special diffusion battery and AIP-2 cascade impactor. During the experiments a significant breakthrough is observed for different aerosol filters. The various size modes of the radioactive aerosols passing throw the filter are studied. At low aerosol concentration, the penetration of 1 nm approximately 1% and for 20 nm is varied from 12 to 20%. The different types of filters prevented all unattached radon decay products and the most size activity became with AMTD ~ 10 nm. At high aerosol concentration, the activity of unattached fraction nearly deleted. The activity of aerosols with AMTD ~ 10 nm is increased. The filters prevented all particles higher than 0.8 µm.

Human pharmacokinetics and internal radiation dosimetry of normal organs after injection with the 99mTc-labeled monoclonal antibody (intact and fragments) are simulated by the WinAct program and IDAC (Internal Dose Assessment by Computer) software. The WinAct program is used to calculate the cumulative activity in organs and tissues. The calculated cumulative activity is inputted to the IDAC software, an internal dosimetry program for nuclear medicine based on the International Commission on Radiological Protection (ICRP) adult reference voxel phantom, and the absorbed doses by the organs and tissues are estimated. The obtained absorbed doses for the 99mTc-labeled monoclonal antibody (intact and fragments) are compared with the published figures by ICRP-128. The WinAct program method to calculate the cumulative activity is more accurate, as the fraction distribution, Fs, is described and calculated for organs, not only for intake, as in the ICRP model, but also for elimination.

In the present study, the transfer factors of the natural radionuclides 238U, 232Th, and 40K were estimated for several crops cultivated in farms in the suburbs of Baghdad and one farm in Al-Najaf. The transfer factor (TF) is the ratio of activity transfers from soil to plant. The specific activities of the natural radionuclides were measured with a gamma-ray spectrometer with a HPGe detector. The crops include cereals (rice and wheat), fruits (lemons and oranges), podded vegetables (vigna and okra), fruity vegetables (chili peppers and Solanum melongena), and leafy vegetables (Apium graveolens, Raphanus sativus, and Ocimum basilicum). The results showed that the highest transfer factors for 238U, 232Th, and 40K are 0.32, 0.70, and 3.44, respectively, in wheat. The average transfer factors for 238U and 232Th were founded 0.23 and 0.2 which are lower than the default unitiy value but the 1.85 were reported for 40K higher than unity.

Uranium, perhaps the most strategically important component of heavy minerals, finds particular significance in the nuclear industry. In prospecting trenches, the radioactivity of 238U and 232Th provides a good signature of the presence of heavy minerals. In the work herein, the activity concentrations of several key primordial radionuclides (238U, 232Th, and 40K) were measured in prospecting trenches (each of the latter being of approximately the same geometry and physical situation). All of these are located in the Seila area of the South Eastern desert of Egypt. A recently introduced industry standard, the portable hand-held RS-230 BGO gamma-ray spectrometer (1024 channels) was employed in the study. Based on the measured data, the trenches were classified as either non-regulated (U activity less than 1000 Bq kg-1) or regulated (with 238U activity more than 1000 Bq kg-1). Several radiological hazard parameters were calculated, statistical analysis also being performed to examine correlations between the origins of the radionuclides and their influence on the calculated values. While the radioactivity and hazard parameters exceed United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) guided limits, the mean annual effective doses of 0.49 and 1.4 mSv y-1 in non-regulated and regulated trenches respectively remain well below the International Commission on Radiological Protection (ICRP) recommended 20 mSv/y maximum occupational limit. This investigation reveals that the studied area contains high uranium content, suitable for extraction of U-minerals for use in the nuclear fuel cycle. © 2021 Hanfi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

In the present study, the transfer factors of the natural radionuclides

Stream sediment is a useful raw material used for building construction, mostly used in the desert parts of the world. Such sediment is a Naturally Occurring Radioactive Material (NORM), and, hence, it requires a radiological characterization to be used. This work aims to study the natural radioactivity in fifty points distributed in surface of stream sediments in the area of Gabal El Seila region, south-eastern desert of Egypt, since there is a lack of information about the radioactivity levels of the sediment samples from such recent growing interest area. The activity concentration of 238U, 232Th and 4 K natural radionuclides using a portable RS-230 γ-ray spectrometer were determined. Mean values are 38.51 ± 10.83, 33.35 ± 8.82, 659.18 ± 110.87 Bq/kg for 238U, 232Th, 4 K respectively. Radiological hazard indexes were computed and compared with the UNSCEAR and other worldwide ranges. All the results are statistically presented and discussed. They show that no significant radiation hazard coming from the studied area, with the most values lower than international recommended limits. The achievements of the present study fall within the measurements of natural environmental radiation in an unexplored area of great interest being a desert. The obtained results can be used as database for future research, and as tool for radiological awareness in the use of sediments as raw material.

A series of bismo-borate (50-x)B2O3-xTiO2-15Na2O–30Bi2O3 glass samples (where x = 0, 2.5, 5, 7.5, and 10 wt%) doped with TiO2 were fabricated via the melt-quenching technique. The gamma and neutron shielding, physical, optical, and mechanical properties of the prepared samples were investigated. The experimental results were measured using an HPGe detector. 152Eu, 133Ba, 137Cs, and 60Co radioactive sources were used with energies in the range of 81–1408 keV. The experimental results were compared with both the FLUKA code and the XCOM database. The addition of TiO2 increased the density of the glass samples and decreased their molar volume. The mass attenuation coefficient (MAC) decreased as photon energy decreased, while it increased as TiO2 concentration increased. The half value layer (HVL) and mean free path (MFP) of the glass samples increased when the photon energy increased and decreased as the TiO2 concentration increased. The absorbance of the present samples is enhanced by using TiO2, meaning they can be used to protect humans from UV light. Both direct and indirect band gaps decreased as TiO2 content increased from 0 to 10 wt %. Moreover, the electronic transition between localized states is valid in the present samples. The radiation shielding, optical, physical, and mechanical properties of the fabricated glass samples demonstrate their utility for diagnostic gamma shielding. © 2020 Elsevier Ltd and Techna Group S.r.l.

The present study aims to measure the activity concentrations of radionuclides 238U, 232Th, 40K, 137Cs in samples of fly ashes collected from two thermal power plant in Iraq, by gamma spectroscopy using a NaI (Tl) detector. The radiological hazard related to these activities is also assessed through several worldwide commonly used indexes established by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). The results are statistically presented, discussed and compared with literature and with worldwide reference averages: no significant radiation hazard comes from the analyzed fly ashes, although ~ 25% of the samples exceed the activity concentration limits.

In this work, six different aerosol sources, used in everyday life, were investigated to analyze parameters such as concentration, size distributions, and dynamics: regular and electronic cigarettes, incense, candles, mosquito coils, and cooking. During the experiments, the aerosol particle count ranged from 200 to 2·105 cm−3. The number, mass, and specific surface area of the aerosol size distributions were measured by a Model 2702 M diffusion aerosol spectrometer (DAS) with a range of 5 nm to 10 μm. The attachment rate of radon decay products to aerosol particles is calculated depending on their size distribution/ The use of household sources of aerosols (heat treatment of food, smoking, candles, etc.) result in an increase in the concentration of aerosol particles by more than an order of magnitude, mainly due to the generation of ultrafine aerosols with number median diameter 64–92 nm and GSD 1.45–1.84. The mass distribution is dominated by particles with a distribution maximum in the range of 2–5 μm. The attachment of radon decay products to aerosols is associated with ultrafine particles with diameter < 200 nm. The median diameter of the rate of attachment to aerosols is 130 nm. © 2021, Springer Nature Switzerland AG.

Composition of (50 − x) B2O3–30PbO–20ZnO–xLa2O3 (x = 0, 1.5, 3, 4.5, and 6) wt% glass system were synthesized using quench melt technique and simulated for their nuclear radiation shielding properties. Moreover, UV–visible absorption spectrum among 190–1100 nm and the glass optical parameters were measured. The optical energy gap (Eg), the single-oscillator energy (Eo), the dispersion energy parameter (Ed), refractive index (n), and refractive dispersion index (no) were estimated. The obtained results indicated that (Eg) was decreased with increasing La2O3 content, but the refractive index (n) was increased. The addition of La2O3 to glass network could provide preferable shielding features. The chosen amount of La and another metal oxide has been added to the glass. Shielding parameters such as half-value layer (HVL), mean free path (MFP), mass attenuation coefficient (MAC), and exposure rate in the photon energy range 15–300 keV have been simulated by MicroShield software. These results illustrate that the La5 glass sample has the best radiation shielding properties, among other investigated glasses. This type of glass sample can utilize for the construction of the monitoring screening windows in radiation areas, plats, or screening windows in X-ray diagnostic and for the walls of CT-scanner rooms. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.

The dynamic of 89Zr-labelled chimeric monoclonal antibody U36 after injection into the human body is modelled based on real clinical results. Results for nine patients (women) from published work is used to create a simple biokinetic model. Cumulative 89Zr Activity in organs and tissues per Bq of administered Activity is calculated with the WinAct program. For the most organs receiving the highest radiation exposure, average absorbed doses were estimated with IDAC 2.1 software. The organs exhibiting the highest dose for adult women were the red bone marrow, lungs, liver, spleen, kidneys, and thyroid (at 1.21,0.837, 0.811, 0.759, 0.745, and 0.411 mGy/MBq, respectively), when the injection was associated with monoclonal antibodies. The results from a new modified biokinetic and modelled calculations are compared with the published experimental diagnostic results conducted in real patients and with given results by OLINDA software, which are in good agreement. Based on real clinical results, the recommended value of blood removing biological time is 65 h for Zr-89 labelled with cMab-U36.

The atomic planes of a crystal cause an incident beam of X-rays to interfere with one another as they leave the crystal. This phenomenon is called X-ray diffraction (XRD). Crystals consist of planes of atoms that are spaced a distance d apart, but can be resolved into many atomic planes, each with a different d spacing. a, b and c (lengths) and α, β and γ are angles between a, b and c those are lattice constants (parameters) which can be determined by XRD. The 6061Al alloys is used as cladding for nuclear reactor fuel so it is very important to study the properties of this alloy by several techniques such as XRD. The aim of this work is using the XRD to study the crystal properties of 6061 Al-alloy which is used for cladding of nuclear fuel by determining the crystallite size, micro strain, defect density, etc. XRD device model no (202964) Operator (Beni Suef University) is used. The results indicate that the crystallite size of 6061 alloys decreases gradually from 0.388 to 0.075 with thickness reduction. Also, the micro-strain and the lattice parameter nearly constant for all degree of deformation only changes irregularly and there is a peak approximately at 9 % of thickness reduction due to the preferred orientation. The dislocation has an exponentially variation from 9.7 x108 cm−2 to 1.14 x109 cm−2.

In this study, nearly 84 marine sediment samples were collected from twelve points in four cities (Quseir, Safaga, Hurghada, and Ras Gharib) along the Egyptian Red Sea sectors. The collected samples were extensively examined to estimate the natural radioactivity level. The obtained results were compared to the reported ranges from other locations in different countries. Hazardous radiation parameters such as radium equivalent, annual dose, and external hazards were estimated and compared to United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) recommended levels. The values were recorded in the first natural radioactivity database of coastal sediments from Egyptian Red Sea cities. The dose rate for certain organs was evaluated. The results showed that Red Sea beach sediments are safe in terms of natural radioactivity. It can be concluded that they do not pose a risk to tourists going to the beaches for recreation or to sailors and fishers involved in economic activities along the Egyptian Red Sea coast.

Objective In this article, IDAC-Dose2.1 and OLINDA computer codes are compared as they are the most widely used software tools for internal dosimetry assessment at the present time. OLINDA/EXM personal computer code was created as a replacement for the widely used MIRDOSE3.1 code. IDAC-Dose2.1 was developed based on the ICRP specific absorbed fractions and computational framework of internal dose assessment given for reference adults in ICRP Publication 133. IDAC uses cumulated activities per administered activity in hours and calculates the absorbed dose and the effective dose. The program calculates the dose in the Eckerman stylized family phantoms. It is useful in standardizing and automating internal dose calculations, assessing doses in clinical trials with radiopharmaceuticals, making theoretic calculations for existing pharmaceuticals, teaching, and other purposes. Methods To produce such a comparison, the results of this work were compared with available published data in the literature on radiopharmaceuticals. Radiopharmaceuticals with 89Zr, 153Sm, 177Lu radionuclides are used as the basis for the comparison. 89Zr, 153Sm, 177Lu radionuclides are regarded as the future of radiopharmaceutical treatment. For 89Zr, two different labelled carriers, Zr-89_cMAb U36 and Zr-89 Panitumumab, were used on patients. Results The results show a clear difference in terms of absorbed dose of the Zr-89 radiopharmaceuticals for red bone marrow when calculated by IDAC-Dose2.1 (0.76 mGy/MBq), while the estimated absorbed dose in literature results is 0.07 mGy/MBq and 0.14 mGy/MBq when the calculation is done by OLINDA program. In the case of 177Lu-EDTMP, the absorbed dose in red bone marrow is in reasonable agreement (0.63 mGy/MBq and 0.8 mGy/MBq for IDAC-Dose2.1 and OLINDA, respectively). A significant difference was found for the absorbed dose in the bone surface, which was almost twice as high for OLINDA (2.1 mGy/MBq for IDAC-Dose2.1 and 5.4 mGy/MBq for OLINDA). In some direct cases, the calculated absorbed dose in the urinary bladder wall with OLINDA is ten times higher compared to WinAct (which was utilized to calculate the total activity in the organs and tissues) and IDAC 2.1. These results are considered key to greater accuracy in internal dose calculation.

Generally, in Nigeria dumpsites are open and elevate the pollution by increasing the total environment contamination level. This affects not only the site of dumpsites but also the surrounding buildings and area. In the present work, indoor radon activity concentration is tested inside some buildings in the vicinity of dumpsites in Lagos, Nigeria. A passive technique with CR-39 detectors is used. Different buildings around different eight dumpsites were chosen. Radon concentration had ranged from 16.00 ± 3 to 931.00 ± 186 Bqm−3 in the dumpsites. With Mean concentrations range from 120 ± 24 at OKE-ODO to 334 ± 67, at Solus-4 respectively. The present results explain that 63% of the radon activity concentration in indoor air around the selected dumpsites at Lagos city in Nigeria is below the allowed limit from ICRP 200 Bq m-3 while 37% is more than this limit. Based on the measured radon concentration, the annual effective dose and cancer risk are evaluated. The range of ELC is from 242 to 14086 with mean value 3114 ± 1111.

The present paper describes the prototype of a calibration standard system for radon concentrations to be used in establishing the traceability of radon concentration measurements in dwellings. Radon gas was generated with a radium-226 solid source in a certified volume as a closed system. The activity of the radon that was released in the closed system was determined from the difference between the absolute activity of the standard radium solid source and the residual radon decay products (214Bi or 214Pb). A high-purity germanium (HPGe) detector, which was calibrated using gamma reference standard sources, was used to measure the activity of a radium solid source and radon decay products (214Bi or 214Pb). The emanation factor of the 226Ra source was controlled online with the HPGe detector. Radon activity was achieved at ~1500±45 Bq from the radium source at 3.95±0.2 kBq under equilibrium conditions. After this activity, the radon gas was transferred into the closed system producing radon activity concentrations of 31.1±0.3 kBq/m3. Systematic errors were found of less than 4% with a random error around 0.5%. The random error is generally associated with the estimation of the count rate of the measured radon progenies (214Po and 214Po for alpha measurements or 214Pb and 214Bi for gamma measurements), but systematic errors are associated with the errors introduced by the instrumentation and measurement technique. The system that was developed has a high degree of accuracy and can be recommended as a national or regional prototype standard of radon activity concentration to calibrate different working radon measurement devices.

The influence of aerosol particle concentration on the activity of short-lived radon decay products (RPDs) was investigated inside a standard radon box. The 218Po:214Pb:214Bi activity ratio was determined for unattached and attached fractions of radon decay products at different aerosol concentrations. For the unattached fraction, this ratio was 1:0.31:0.06, while for the attached aerosol fraction the activity ratio was 1:1.4:0.91 at a low aerosol concentration (2000 cm−3) and with the unattached fraction fp = 0.45. In this case, there was no additional aerosol in the standard radon box and the equilibrium shift ratio for the total activity (attached and unattached) was 1:0.55:0.27 for 218Po:214Pb:214Bi. When the aerosol was injected, the unattached fraction nearly disappeared at a high aerosol concentration (80000-90000 cm−3). The equilibrium shift ratio for the total activity at a high aerosol concentration was 1:2:1.5 for 218Po:214Pb:214Bi. This ratio was the same for the attached fraction. For no more than 0.01 of the unattached fractions, this ratio was 1:0.85:0.7. Radioactive equilibrium factors and unattached fractions were also determined at different aerosol particles concentrations. A negative correlation between unattached fraction and the radioactive equilibrium factor, as well as a positive correlation coefficient between the radioactive equilibrium factor and aerosol particle concentration in a standard radon box, has been determined.

Urban road sediments act as large basins for heavy metal contaminants produced as a result of natural processes and anthropogenic activities. This study is aimed at reviewing research over recent decades on heavy metal contamination in different cities around the world. The study reviews literature from Google Scholar, Web of Science, and Scopus journal publications. Cr, Cu, Pb, Zn, Ni, and Cd levels vary from one city to another. Based on the collected results, the pollution level and geoaccumulation index are estimated in each city. The levels of pollution in these cities range from low to extremely high, depending on the sources of pollution at each site (geogenic and anthropogenic sources, etc.) and factors like the distribution of industrial activities, population, and traffic emissions. This review shows that the development of modern cities and rapid urbanization are the major causes of heavy metal contamination in the environment. The contamination of the urban environment has different sources, both natural and anthropogenic in character. Solving the problem of heavy metal contamination in the urban environment requires the use of different techniques such as urban road control treatment and soil remediation.

177Lu refers to rare earth elements from a group of lanthanides. Relative to its short time span, 177Lu has virtually pervaded all areas of in vivo radionuclide therapy and becomes one of important keys for therapeutic radionuclides of choice for targeted radionuclide therapy. The rising interest in the use of 177Lu in targeted molecular therapies has primarily developed from recent unmatched advances in molecular and cell biology, which include the use of peptides targeted to cell surface receptors, which are overexpressed on the surface of tumour cells. Therefore, the use of 177Lu-labelled radiopharmaceuticals have been the major factors evoking excitement among researchers and capturing the imagination of the clinical community thanks to advances in molecular and cellular biology. In this work, radiopharmaceutical comparison for 177Lu absorbed dose in health human organs and tissues is presented. The comparison between unlabelled 177Lu (ionic form) and labelled with 177Lu-MDP (methylenediphosphonate) and 177Lu-MAb (monoclonal antibodies). The biokinetic model in each case are described and presented. The absorbed dose in health human organs and tissues are simulated with two recommended programs WinAct and IDAC 2.1(Internal Dose Assessment by Computer) software. The distribution of absorbed dose in the main organs nearly the same with different in the value for the ionic form and 177Lu-MDP. The absorption in the case of ionic form is high. The distribution is completely change while 177Lu-MAb is used. The most absorbed dose fraction goes to spleen and liver unlike bone surface absorb nearly 50 % of dose. © 2019 Author(s).

Particle size distribution is an important factor governing whether aerosols can be deposited in various respiratory tract regions in humans. Recently, electronic cigarette (EC), as the alternative of tobacco cigarette, has become increasingly popular all over the world. However, emissions from ECs may contribute to both indoor and outdoor air pollution; moreover, comments about their safety remain controversial, and the number of users is increasing rapidly. In this investigation, aerosols were generated from ECs and studied in the indoor air and in a chamber under controlled conditions of radon concentration. The generated aerosols were characterized in terms of particle number concentrations, size, and activity distributions by using aerosol diffusion spectrometer (ADS), diffusion battery, and cascade impactor. The range of ADS assessment was from 10−3 μm to 10 μm. The number concentration of the injected aerosol particles was between 40 000 and 100 000 particles/cm3. The distribution of these particles was the most within the ultrafine particle size range (0–0.2 μm), and the other particle were in the size range from 0.3 μm to 1 μm. The surface area distribution and the mass size distribution are presented and compared with bimodal distribution. In the radon chamber, all distributions were clearly bimodal, as the free radon decay product was approximately 1 nm in diameter, with a fraction of ~0.7 for a clean chamber (without any additional source of aerosols). The attached fraction with the aerosol particles from the ECs had a size not exceeding 1.0 μm.

AFA-RSP-20 radiometric analytical filter is one of the most used Petryanov filters in radiation protection and alpha measurements (radiometry and spectroscopy). Therefore, the properties of this filter like efficiency and the permeability of the radioactive aerosol particles through it is more important for accurate dose estimation. In this work, an experimental setup has been constructed to study the efficiency and permeability of the radioactive aerosol particles through AFA-RSP-20 radiometric analytical filter. A standard radon chamber, 2 m3, at Ural Federal University is used. The dependence of RSP filter efficiency on the aerosol concentration and air sampling velocity is tested and the relation is described. The RSP filter efficiency increasing with the aerosol number concentration at different air velocity. The value of the efficiency was between 92–97 %. Due to the aerosol activity level increases in the radon chamber, the sensitivity of the measurements is sufficient for a correct estimation of the permeability of radioactive aerosols passed through the RSP filter. The effect of size modes of the radioactive aerosols passing throw the filter is studied with special diffusion battery. At low aerosol concentration, the filter prevented all unattached radon decay products (1–5 nm) and the most size activity became with AMTD ∼20 nm. At high aerosol concentration in the radon chamber, the activity of unattached fraction nearly deleted. The activity of aerosols with AMTD ∼20–40 nm is increased.

In this paper, SRIM (The Stopping and Range of Ions in Matter) software package is used to simulate the interaction of alpha particles into the material of radiometric analytical filters. The effect of alpha particle self-absorption in alpha radiometric filters measurements is estimated, especially in the range of natural alpha energy (5-9 MeV, Radon and Thoron alpha energy). Software package SRIM allows to calculate the parameters of the ions interaction with target material using a Monte Carlo simulation method based on a quantum mechanical treatment of ion-atom collisions. The effect of the radiometric analytical filter material on the transmitted efficiency of alpha energy is discussed. As the energy increases the self-absorption in analytical filter material is decreased but still has a clear effect. In this case, the filter material and the space distance between the filter and the detector window decrease the number of alpha particles which reach to the detector window. © 2019 RAD Association. All rights reserved.

The activity particle size distribution is an important factor governing if the aerosols can be deposited at various respiratory tract regions in human. Radon decay products are the second cause of lung cancer after smoking. A lot of dosimetric models have been built in to calculate the effective dose and effective depth dose in different region and tissues of human respiratory system. The deposition fraction estimation is the first step of dose calculation. Therefore, the dependence of radioactive aerosols deposition fraction in human respiratory system on their size should be studied. In this work, the activity size distributions of 222Rn decay products (218Po, 214Pb and 214Bi,) are measured in indoor air. Only unattached fraction of 218Po (active median thermodynamic diameter AMTD∼1-1.5 nm) was measured with developed diffusion battery. Nearly 85% of 218Po activity is free with its short half-life time. Most of the measured attached activities of (214Pb and 214Bi) are associated with the aerosol particles of the accumulation mode (0.2 μm to 2 μm). The activity distribution of the two radionuclides is typically identical. The active median aerodynamic diameter (AMAD) is 0.42 μm with a geometric standard deviation (GSD) of 3.4. Given that dose estimation is sensitive to environmental conditions and based on the obtained experimental results, the local energy deposition of (214Pb and 214Bi) by adult male for various levels of physical exertion (sleeping, sitting, light exercise and Heavy exercise) is computed with LUDEP program. For unattached particles (1-5 nm) nearly 98% are deposited unlike accumulated fraction (0.42 μm in our case) not more 30 % is deposited in the respiratory system. © 2019 Author(s).