Nanoclay-reinforced polymers have attracted considerable universal attention in academic and industrial research due to their outstanding properties and their ever-expanding utilization in ...diversified applications. In that regard, in the present review, the structure of layered silicate clay, as well as procedures for clay material modification, are outlined. We also discuss the general characterization techniques, synthesis methods, and various properties of polymer-clay nanocomposites (PCNs), and some examples likewise are depicted from the scientific literature. The study's primary goal is to provide an up-to-date survey of polymer-clay nanocomposites and their specific applications in industries such as automotive, flame-retardant, and biomedical applications, coating, and packaging.
The aim of this study is to assess the individual gamma-ray transmission factors (TFs) and some fundamental gamma-ray attenuation properties of several types of glasses based on WO
–TeO
–B
glasses ...system. MCNPX (version 2.7.0) is used for the calculation of TFs. Other critical parameters are determined using the Phy-X/PSD program. To determine the TFs of studied glasses, several medical radioisotopes are determined along with their characteristic gamma-ray energies. The superior values for the investigated parameters are found in glass sample S6. Furthermore, the exposure build-up factor and energy absorption build-up factor values for glass sample S6 were the lowest. S6 glass sample with the chemical composition 0.03833B + 0.26075O + 0.11591Zn + 0.52783Te + 0.05718W and a density of 3.3579 g/cm
is found to have exceptional gamma-ray attenuation qualities, according to our findings. It can be concluded that the prospective attributes of WO
-doped glass systems and associated glass compositions would be beneficial for scientific community in terms of providing a clearer view for some advanced applications of these glass types.
We report some fundamental gamma-ray shielding properties and individual transmission factors (TFs) of five distinct glass samples with a nominal composition of
Sb
·(40 −
)PbO·60B
·0.5CuO and (where; ...0 ≤
≤ 40 mol%). Phy-X/PSD and MCNPX (version 2.7.0) Monte Carlo code are utilized to determine several critical parameters, such as cross-sections, attenuation coefficients, half and tenth value layers, build-up factors, and TFs. A general transmission setup is designed using basic requirements. Accordingly, TFs are evaluated for several medical radioisotopes. Next, the gamma-ray shielding parameters and TFs are assessed together in terms of providing the validity of the findings. Our results showed that there is a positive contribution of increasing Sb
amount in the glass matrix owing its direct effect to the density increment as well. This positive effect on gamma-ray shielding properties is also observed for decreasing mean free path values from S1 to S5 samples. The exposure build-up factor (EBF) and energy absorption build-up factor (EABF) values, increasing the quantity of Sb
supplementation, resulted in a general reduction in EBF and EABF values (i.e., from 0.5 to 40 mfp). When the quantity of Sb
rises from S1 to S5, the collision rate of incoming gamma rays in glass samples increases significantly. The TF figures reveal that S5 showed the least transmission behavior across all the above-mentioned studied glass thicknesses. It can be concluded that increasing the Sb
additive is a beneficial and monotonic technique, when the gamma-ray shielding qualities or TF values must be further enhanced.
The paper presents the results of a national radon survey conducted in the context of the Republic of Moldova. The study included about 2500 homes of different types, located in urban and rural ...localities in different areas of the country. The RADTRAK2 detectors kindly provided by the RADONOVA laboratory, Uppsala, Sweden, for the MOL9007 project funded by the International Atomic Energy Agency (IAEA) have been used. The exposure period was 90 days. The measured radon concentrations are the following: the average (±standard deviation) 252.8 ± 215.9 Bq/m3; the range (minimum–maximum) 10–1480 Bq/m3; the median 200 Bq/m3 and the geometric mean (± geometric standard deviation) 158.5 ± 3.0 Bq/m3. The results of the study allowed mapping indoor radon and identifying localities with increased radon concentrations. In order to reduce the high radon concentrations in places recording >300 Bq/m3, appropriate measures have been proposed according to the legislation in force. The cluster analysis showed positive links between the radon concentration in dwellings and the incidence of respiratory diseases, especially the bronchopulmonary cancer in the country.
Natural radioactivity, radiological hazard, and petrological studies of Homrit Waggat granitic rocks, Central Eastern Desert, Egypt were performed in order to assess their suitability as ornamental ...stone. On the basis of mineralogical and geochemical compositions, Homrit Waggat granitic rocks can be subdivided into two subclasses. The first class comprises granodiorite and tonalite (I-type) and is ascribed to volcanic arc, whereas the second one includes alkali-feldspar granite, syenogranite, and albitized granite with high-K calc alkaline character, which is related to post-orogenic granites. 238U, 226Ra, 232Th, and 40K activities of natural radionuclides occurring in the examined rocks were measured radiometrically using sodium iodide detector. Furthermore, assessment of the hazard indices—such as: annual effective dose (AED) with mean values (0.11, 0.09, 0.07, 0.05, and 0.03, standard value = 0.07); gamma radiation index (Iγ) with mean values (0.6, 0.5, 0.4, 0.3, and 0.14, standard value = 0.5); internal (Hin) with mean values (0.6, 0.5, 0.4, 0.3, and 0.2, standard value = 1.0); external (Hex) index (0.5, 0.4, 0.3, 0.24, and 0.12, standard value = 1.0); absorbed gamma dose rate (D) with mean values (86.4, 75.9, 53.5, 43.6, and 20.8, standard value = 57); and radium equivalent activity (Raeq) with mean values (180, 154, 106.6, 90.1, and 42.7, standard value = 370)—were evaluated with the knowledge of the natural radionuclides. The result of these indices falls within the acceptable worldwide limits. Therefore, we suggest that these rocks are safe to be used in industrial applications.
The ceramic and porcelain industry in the Arab Republic of Egypt annually produces a huge amount of by-product waste. Public health is threatened by the accumulated ceramic and porcelain dust and ...crumbs. In this study, five different ceramic and porcelain waste samples were recycled in glass form of xLiNbO3-(40-x)Waste and investigated with different LiNbO3 contents of x = 8, 16, 20, 24, 32 wt.% for useful nuclear radiation shielding applications. The amorphous structure of prepared samples is assured with XRD analyses. The radiation protection features of the prepared samples were investigated experimentally and compared with theoretical calculations for photon energies in the range of 81–2614 KeV. Moreover, optical parameters of waste glasses such as absorption coefficient, skin depth, and extinction coefficient have been calculated. The radiation protection factors showed that the Waste32 sample with 32 wt.% LiNbO3 is the best shield out of the fabricated Waste-x samples. The insertion of ceramic and porcelain wastes in the glass system reached 32 wt.%.
The direct influence of La
ions on the gamma-ray shielding properties of cobalt-doped heavy metal borate glasses with the chemical formula 0.3CoO-(80-x)B
O
-19.7PbO-xLa
O
: x = 0, 0.5, 1, 1.5, and 2 ...mol% was examined herein. Several significant radiation shielding parameters were evaluated. The glass density was increased from 3.11 to 3.36 g/cm
with increasing La
ion content from 0 to 2 mol%. The S5 glass sample, which contained the highest concentration of La
ions (2 mol%), had the maximum linear (μ) and mass (μ
) attenuation coefficients for all photon energies entering, while the S1 glass sample free of La
ions possessed the minimum values of μ and μ
. Both the half value layer (T
) and tenth value layer (TVL) of all investigated glasses showed a similar trend of (T
, TVL)
> (T
, TVL)
> (T
, TVL)
> (T
, TVL)
> (T
, TVL)
. Our results revealed that the S5 sample had the highest effective atomic number (Z
) values over the whole range of gamma-ray energy. S5 had the lowest exposure (EBF) and energy absorption (EABF) build-up factor values across the whole photon energy and penetration depth range. Our findings give a strong indication of the S5 sample's superior gamma-ray shielding characteristics due to the highest contribution of lanthanum oxide.
The radiation shielding characteristics of samples from two TeO2 and Sb2O3-based basic glass groups were investigated in this research. TeO2 and Sb2O3-based glasses were determined in the research as ...six samples with a composition of 10WO3-(x)MoO3-(90 − x)(TeO2/Sb2O3) (x = 10, 20, 30). A general purpose MCNPX Monte Carlo code and Phy-X/PSD platform were used to estimate the radiation shielding characteristics. Accordingly, the linear and mass attenuation coefficients, half value layer, mean free path, variation of the effective atomic number with photon energy, exposure and built-up energy factors, and effective removal cross-section values were determined. It was determined that the results that were produced using the two different techniques were consistent. Based on the collected data, the most remarkable findings were found to be associated with the sample classified as T80 (10WO3 + 10MoO3 + 80TeO2). The current study showed that material density was as equally important as composition in modifying radiation shielding characteristics. With the T80 sample with the greatest density (5.61 g/cm3) achieving the best results. Additionally, the acquired findings were compared to the radiation shielding characteristics of various glass and concrete materials. Increasing the quantity of MoO3 additive, a known heavy metal oxide, in these TeO2 and Sb2O3-based glasses may have a detrimental impact on the change in radiation shielding characteristics.
This study aimed to perform an investigation for the potential implementation of bismuth silicate glasses as novel shield equipment instead of ordinary shields in nuclear medicine facilities. ...Accordingly, a group of Bi2O3 reinforced silicate glass system were investigated and compared with ordinary shields in terms of their gamma-ray attenuation properties in diagnostic nuclear medicine radioisotope energies emitted from 99mTc, 111In, 67Ga, 123I, 131I, 81mKr, 201Tl, 133Xe. Mass attenuation coefficient (μm) results for glass samples were calculated comparatively with the XCOM program and MCNPX code. The gamma-ray attenuation parameters such as half value layer (HVL), tenth value layer (TVL), mean free path (MFP), effective atomic number (Zeff) were obtained in the diagnostic gamma ray energy range from 75 to 336 keV. To confirm the attenuation performance of superior sample, obtained results were extensively compared with ordinary shielding materials. According to the results obtained, BISI6 glass sample with the highest Bi2O3 additive has an excellent gamma-ray protection.
Role of V
2
O
5
as a strong network glass modifier on the optical, elastic, physical, and radiation protection performance of V
2
O
5
-based glasses in form 10CaF
2
-(20-x)Bi
2
O
3
-60P
2
O
5
-10B
2
...O
3
:xV
2
O
5
, x = 0.0, 0.5, 1.0, 1.2, 0.2, and 2.5 mol% was investigated in this article. The studied glasses have been synthesized using the melt-quenching technique. The investigated samples coded as V0, V1, V2, V3, V4, and V5 according to x values. Difference theoretical approaches have been utilized to achieve these goals including: radiation shielding calculations, optical, and elasto-mechanical properties. The optical basicity (Λ(E
g
)) was found to decrease from 0.5630 to 0.5593 with increasing the mol% of V
4+
in the glass samples. The density was decreased from 4.134 to 3.817 g cm
−3
associated with a simultaneous decrease in the oxygen molar volume (OMV) from 12.5 to 12.25 cm
3
/mol as the mol% of V
4+
increased in the samples. The Vicker’s hardness was found to be diminished with increasing V
2
O
5
content in the investigated glasses. All elastic moduli were reduced as V
2
O
5
increased. Refractive index increased from 2.20 to 2.63, while metallization criterion decreased from 0.341 to 0252. The observed trend of mass attenuation coefficient (MAC) values in the tested energy spectrum followed the sequence: (MAC)v
0
> (MAC)v
1
> (MAC)v
2
> (MAC)v
3
> (MAC)v
4
> (MAC)v
5
. Also, we found that linear attenuation coefficient (LAC) increased, while the half value layer (HVL), and transmission coefficient (TF%) were also decreased. The HVL values of the current samples were compared with standard glasses, and it found that V
2
O
5
-based samples possess a comparable photon protection capacity as commercial RS-360 and RS-520 glasses.
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