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The gamma ray shielding characteristics of different borosilicate glasses are examined in this work. Four glasses with a composition of 60B2O3–5Na2O–5PbO–(30-x)SiO2–xBaO, (x = 5, 10, 15, and 20 mol%) were created using the conventional melt quenching technique followed by an annealing step. Linear attenuation coefficient, LAC, values have been determined using HPGe semi-conductor detector. These values were compared with calculated values estimated from Phy-X software and a good matching was observed. The samples were irradiated using the point sources viz., Am241 (0.0595 MeV), Cs137 (0.6617 MeV) and Co60 (1.173 and 1.330 MeV). The LAC data were further utilized in computations of other radiological parameters that are half value layer (HVL) and Tenth value layer (TVL). Furthermore, radiation shielding efficiency (RSE) of the prepared glass materials has been evaluated. The sample 10S20B exhibits higher values of LAC than the others because it has the largest density and weight fraction of elements with higher atomic numbers. The significance of the atomic number and density parameters-higher atomic number and density imply greater probability of interaction, leading to better attenuation. [ABSTRACT FROM AUTHOR]

In this work we investigated new different glass compositions 20PbO–20BaO–(60 − x)B2O3–xZnO (x = 0, 5, 10, 15 and 20 mol%) to study the radiation shielding capability of these glass composites. The shielding ability was measured experimentally using narrow beam method (which including HPGe detector, point sources and lead collimators). The accuracy was verified by XCOM software, the linear attenuation coefficient (LAC) of the produced glasses was ascertained using both methods. We noticed that the B40Z20 glass composite (contain 20 mol%) has the highest LAC at the four examined energies (0.060, 0.662, 1.173 and 1.333 MeV) since the LAC enhances as the ZnO content increases from 0 to 20 mol%. The based shielding parameters such as HVL and RSE or called radiation shielding efficiency were determined experimentally. The HVL reduces as the glasses' density (or, more accurately, the amount of ZnO) increases. At 0.06 MeV, the HVL have the following values: 0.041, 0.039, 0.038, 0.036 and 0.035 cm for the glasses with density of 3.582, 3.739, 3.897, 4.055 and 4.212 g/cm3 respectively. [ABSTRACT FROM AUTHOR]

A novel glass system B2O3–SiO2–Bi2O3–TeO2–BaO–ZnO doped with Eu2O3 (x = 0–4 mol%) is fabricated through melt-quench technique and coded as BiTeEu-x. Density and refractive index measurements done on the glasses resulted in the increase up to 5.4377 gcm−3 and 1.99, respectively, for 4 mol% addition of Eu2O3. Vickers micro-indentation measurements done on synthesized glasses gave increasing microhardness values with Eu3+ doping due to higher bond strength of Eu–O bond compared to Te–O bond. The Phy-X/PSD simulation software utilized for obtaining radiation shielding parameters produced highest range of mass attenuation coefficient (63.878–0.036 cm2/g) and lowest range of half-value layer (0.002–3.551 cm) for the same glass proving its superiority in radiation attenuating capacity. This article addresses the theoretical analysis of photon buildup occurring inside the fabricated glasses in 0.015–15 MeV energy range with respect to different penetration depths. Neutron shielding ability of BiTeEu-4 glass was found to be impressive with fast neutron removal cross section (FNR) value of 0.10362 cm−1. [ABSTRACT FROM AUTHOR]

The current study investigates the radiation shielding characteristics of 5Al2O3-25PbO-10SiO2-(60-x) B2O3-xBaO, (x = 5, 10, 15 and 20 mol%) at the low energy region of 15–150 keV. The prepared glasses' linear attenuation coefficient (LAC) proportionally increased with the inclusion of BaO, which suggested a declining tendency in the radiation transmission that corresponds to the addition of BaO. The LAC values are very high at 15 keV, varying in the 351.85–302.77 cm−1 range. The half value layer (HVL) decreases with increased density, with the decline particularly evident at 150 keV. Besides, the addition of BaO in the glasses causes a decrease in the average HVL. We examined the glass thickness necessary for a reduction in the radiation intensity with an energy of 30 keV to 90%, 50%, 25%, 10%, and 0.01% of its starting value. The values of these previous parameters are respectively 0.0016, 0.0105, 0.0209, 0.0348 and 0.0697 cm, which implies that the radiation barrier thickness should be increased to achieve the required level of attenuation. [ABSTRACT FROM AUTHOR]

This study examines the physical, optical and mechanical characteristics of BWP glasses. The density and molar mass increase as the WO3 concentration rises, resulting in a denser and more substantial glass sample. However, the molar volume decreases, indicating a reduction in volume due to the increased density caused by WO3. The inclusion of WO3 also leads to a tighter spacing between atoms. The optical basicity of the glass increases with higher WO3 concentrations. The electronegativity decreases, suggesting the glass becomes more electron-donating. The electronic polarizability and cross-link density increase, resulting in a stiffer and more robust glass network. The mechanical moduli, including Young's modulus, bulk modulus, shear modulus, and longitudinal modulus, also increase with higher WO3 concentrations, indicating improved mechanical characteristics and reduced deformation. The Poisson's ratio shows a larger transverse deformation tendency with increasing WO3 concentration. Micro-hardness values increase with WO3 content, indicating enhanced durability and mechanical robustness. The mean free path values indicates that the higher WO3 content, or lower P2O5 content, improves the shielding ability. [ABSTRACT FROM AUTHOR]

Borosilicate glass doped with lead oxide (75-x)B2O3-5SiO2-10 Li2CO3-10ZnO-xPbO, where x = 5, 10, 15, 20, and 25 mol%, was created using the melt quenching technique. As the PbO level rises from 5 to 25%, the samples’ density grows from 2.6584 to 4.1435 g/cm3, while their molar volume values decline from 29.4981 to 26.339 cm3. UV–visible measurements revealed a reduction in the optical energy gap, an improvement in optical absorption, and an optical redshift toward higher wavelengths. While the direct optical band gap (EOBG) ranged between 5.32 and 3.01 eV, the corresponding indirect optical band gap (EOBG) fell from 4.82 to 3.13 eV. There was an increase in the Urbach energy (EU) from 0.257 for P-5 to 0.293 eV for P-25. Plotting the dielectric constant (ε1, ε2), extinction coefficient (k), and refractive index (n) as a function of wavelength reveals that they all rise as the PbO content in the glass structure increases. The current research also focuses on examining how PbO affects the glass system’s ability to protect from gamma rays using the computer programs Phy-X/PSD and XCOM. At gamma ray energy of 0.5 MeV, the recorded data showed an enhancement in the linear attenuation coefficient of the manufactured composites from 0.2338 to 0.4143 cm−1. Furthermore, the half-value thickness values of the produced composites decrease from 2.965 to 1.673 cm, respectively, due to the additional PbO content of (5–25) mol%. [ABSTRACT FROM AUTHOR]

Trivalent erbium ions doped (48 – x) AlPO4 + 15K2O + 12MgF + 20Na2O + 5NaF + xEr2O3 glass samples have been prepared utilizing the melt-quench process and studied to understand the efficacy of Er3+ ions content on physical, structural and luminescence attributes of host glass. The functional groups of the glass structure such as metaphosphate, orthophosphate and pyrophosphate have been elucidated through Fourier Transform Infrared (FTIR) spectroscopic investigation. The least-square approach was used to calculate the Judd–Ofelt parameter from the oscillator strength of the Er3+ ion transitions. The luminescence emission data captured in the visible and near-infrared (NIR) province using 380 and 980 nm excitation wavelengths. The up-conversion (recorded at the excitation at 980 nm) of 0.5 Er glass exhibited emission at 664, 550 and 488 nm wavelengths. The decay plots of the studied glass specimens were measured at 980 nm excitation. The McCumber (MC) theory has been implemented to calculate the gain coefficient of the 0.5 Er glass and flat gain curve was drawn for S-band, C-band and L-band. The attributes for optical amplification were ascertained, including the quality factor (0.85), branching ratio (1), stimulated emission cross-section (1.3 × 10–20 cm2), gain bandwidth (1.26 × 10–25 cm3) and optical gain (0.394 × 10–23 cm2 s) for 0.5 Er glass. The yellowish green light emission ability of the 0.5 Er glass after 980 nm excitation evident through CIE co-ordinates position (x 0.36, y 0.58) at 1931 CIE chromaticity diagram. The spectroscopic and luminescence results endorse that the alumino–phosphate glass specimens loaded with 0.5 mol% of Er2O3 are beneficial for NIR and green light emission applications. [ABSTRACT FROM AUTHOR]

This study investigates the effects of increasing PbO concentration on the Al2O3–PbO–B2O3–SiO2 glasses' physical, mechanical and gamma ray shielding properties. PbO addition leads to higher density and molar mass, making the glass denser. However, molar volume decreases, indicating a more compact structure. Interatomic distances and ion concentration change, strengthening atomic interactions. Oxygen molar volume increases, but packing density drops with more PbO, impacting the glass lattice. Optical basicity rises, suggesting improved electron transport and optical behavior. Electronegativity decreases, and electronic polarizability increases with higher PbO content, rendering the glass more electron-donating and sensitive to external electric fields.This study investigates glass mechanical properties using the Makishima–Mackenzie model. As PbO concentration rises, elastic moduli consistently decrease, signifying increased flexibility in glass structures. The mass attenuation coefficients (MAC) of the chosen glasses were evaluated in the 0.284–1.333 MeV energy range. It was found that increased PbO content leads to a corresponding MAC enhancement. The MAC values at 0.284 MeV were 0.297 and 0.349 cm2/g, while at 0.511 MeV they varied between 0.124 and 0.135 cm2/g. It was found that Glass Pb47.5 sample, which contains a higher amount of PbO compared to the other glasses, had the highest MAC at all energies. The results showed that the PbO has a notable impact on the MAC and thus on the radiation attenuation performance at lower energy. Moreover, increased glass density led to a corresponding LAC increase, which at 0.284 MeV increased from 1.269 cm−1 for Pb32.5 to 1.898 cm−1 for Pb47.5. According to the LAC results, one simple means of enhancing the glasses' radiation shielding properties is utilizing a high PbO percentage. This paper aims to illuminate silicate glasses' radiation shielding abilities. The paper will investigate the efficiency under specific conditions, like high-energy radiation. Moreover, it will explore innovative methods to enhance their shielding competence, concreting the way for a better yet effective radiation shielding approach. [ABSTRACT FROM AUTHOR]

The glasses' density, molar volume, and molecular weight increase with increasing lead concentration for the PbO–Bi2O3–ZnO–B2O3 glasses. The ion concentration and field strength increase with increasing PbO concentration. Changes in the packing density and oxygen molar volume suggest network changes of a structural nature. The increase in optical basicity and decrease in electronegativity values indicate a higher electron-donating tendency of the glasses with increased concentration of PbO, while the increase in electronic polarizability suggests greater distortion susceptibility due to an externally located electric field. Makishima-Mackenzie's theory was used to study the outcome of lead oxide concentration on the glass's mechanical properties. The increase in PbO concentration results in increased network complexity and stiffness, together with elevated dissociation energy. However, this also results in a decrease in packing density and elastic moduli. The Poisson ratio decreases, indicating cross-linking in the glass network, and the fractal bond connectivity parameter indicates a three-dimensional network. The radiation shielding capability has been compared to other glasses as well and it is found that 70PbO–10Bi2O3–10ZnO–10B2O3 sample is a superior choice for radiation shielding glass. [ABSTRACT FROM AUTHOR]

Herein, the nonlinear optical (NLO) and optical limiting (OL) features of silver nanoparticles (NPs) and holmium ions containing borate-based glasses bearing the nominal composition (79–x)B2O3–15Na2O–5La2O3–1Ho2O3–xAgCl (x = 0, 0.1, 0.25, 0.5, and 0.75 mol%) were deliberated at 532 nm pumping utilizing the nanosecond laser pulses. We studied the NLO and OL characteristics of AgCl content varied glasses and identified that the Ho3+-doped glasses containing 0.5 mol% of AgCl was found to be optimized one. Then, for further tuning of the NLO traits, thermal treatment on optimized glass was carried out at 450 °C for diverse durations. The NLO absorption (two‒photon) and refraction (positive) features were noted to improve with AgCl content and thermal treatment duration, while the OL threshold followed an opposite trend. The enhance of NLO characteristics and OL performance of glasses was resulted on account of local field effect. The outcomes of the study endorse the Ho3+‒doped titled glass containing 0.5 mol% of AgCl thermally treated for 35 h at 450 °C is beneficial for data storage, signal processing and harmonic generation functionalities. Additionally, the enhance of NLO absorption along with decrease of OL threshold results acknowledge the same glass system is useful for OL applications for suppressing high energy coherent radiation in protecting the sensitive optical devices and human eye from laser damage. [ABSTRACT FROM AUTHOR]

A host network of borosilicate glass was produced and reinforced with Bi3+, Ba2+, and Pb2+ ions to be used as protective materials against gamma rays. Four glasses, host 70B2O3–30SiO2 (BSi), 40B2O3–30SiO2–30Bi2O3 (BSiBi), 40B2O3–30SiO2–30BaO (BSiBa), and 40B2O3–30SiO2–30Pb3O4 (BSiPb), were produced. A perfect amorphous structure was observed in X-ray diffraction patterns for all the considered glasses. The structural results showed that BSiBi glass was enriched by non-bridging oxygens NBO units, while BSiBa and BSiPb glasses were enriched by bridging oxygens BO, leading to more tightness of BSiBa and BSiPb glasses than BSiBi. The structural changes clearly reflected on the thermal and optical properties of the considered glasses, where a clear agreement between the network crowding by NBO or BO units and the behavior of the glass transition temperature, band gap, Urbach energy, and refractive index was observed. The considered BSiBi, BSiBa, and BSiPb glasses had thermal stability of 177.931, 264.634, and 231.036 °C and refractive indices of 2.292, 2.225, and 2.175, respectively. From the elasticity point of view and based on the structural changes, the elastic moduli of the BSiBa and BSiPb glasses were consistent with the tightness and formation of BO units, while those of the BSiBi glass were the opposite of what was expected. Bi3+, Ba2+, and Pb2+ enhanced the elastic moduli of the host glass by 70.648–88.042, 119.470–133.114, and 191.773–217.856%. All the considered glasses have high transparency (> 74%). Reinforcing the host glass with Bi3+, Ba2+, and Pb2+ significantly improved its attenuation of 661.64, 1173.23, and 1332.51 keV gamma ray energies. It was found that the BSiBi glass is the best attenuator, followed by BSiPb, but with a very high affinity, while the BSiBa is the least attenuator. For the used gamma rays 661.64, 1173.23, and 1332.51 keV, Bi3+ improved the attenuation ability by 126.087, 134.546, and 115.888%; Ba2+ improved it by 57.764, 69.091, and 63.551%; and Pb2+ by 118.012, 110.909, and 107.477%, respectively. Hence, the suitable thermal, mechanical, optical, and attenuation properties of the BSiBi, BSiBa, and BSiPb glasses open up prospects for them as radiation shields in nuclear fields such as immobilization & disposal of radioactive wastes, radiotherapy rooms, and hot cells. [ABSTRACT FROM AUTHOR]

Bi2O3–TeO2–CdO glasses' structural, thermal, optical, and gamma ray shielding behaviour were studied. Raman spectroscopy revealed that the glasses include BiO3, BiO6, TeO4, TeO3 units as well as CdO metal oxide clusters. The glasses lost just a small percentage of their original weight (less than 2%) on heating upto 800 °C, indicating that they can survive extreme heat without suffering any major changes to their structure or capabilities. The glass transition temperature (Tg) drops from 455 to 408 °C when Bi2O3 is added. The thermal profile of the glasses shows two exothermic peaks. As the Bi2O3 concentration in the samples rose, the indirect band gap energy dropped from 3.066 to 2.951 eV. With the use of the Phy-X program, the radiation shielding parameters have been calculated for the prepared glasses for energies ranging from 0.015 to 15 MeV. The linear attenuation coefficient (LAC) is high at 0.015 MeV (varied between 485.4 and 538.8 cm−1 for CTB4 glass, which is the glass with the largest percentage of Bi2O3, demonstrates the highest levels of LAC. The enhancement in the LAC due to the inclusion of Bi2O3 is observed in the prepared glasses. The enhancement in LAC is more pronounced at lower energies, especially below 0.03 MeV. From the effective atomic number data, increasing the amount of Bi2O3 in the glasses results in improved radiation shielding efficacy, particularly at lower energy. [ABSTRACT FROM AUTHOR]

The incorporation of Bi2O3 in the Bi2O3–BaO–V2O5 (BBV) glasses leads to higher density and molar volume. The average cross-link density ( n ¯ c ) increases from 4.2 to 4.8 cm−3 whereas the number of bonds per unit volume (nb) decreases from 4.974 × 1022 to 4.753 × 1022 as Bi2O3 is incorporated into the BBV glasses. The high values of elastic moduli indicate that the present glasses are resistant to any kind of the deformations when subjected to any kind of forces. The fractal bond connectivity (d) values indicate the 2D structure of the present glasses. Using Phy-X software, the radiation shielding capabilities were studied when Bi2O3 was used in place of BaO. The authors determined the linear attenuation coefficient (LAC) and discussed the change in this parameter due to the addition of Bi2O3 to the glasses. The glass with 20 mol% of Bi2O3 has the highest LAC and also has the highest effective atomic number. The minimum half value layer values was reported at 0.284 MeV and are equal to 1.220, 0.964 and 0.691 cm for the glasses with 5, 10 and 20 mol% of Bi2O3 respectively. The HVL increases with increasing energy, indicating that the samples are more efficient at shielding the low-energy radiation. At 0.347 MeV, the Zeff values are equal to 18.16, 21.09 and 26.05 for the samples with 5, 10 and 20 mol% of Bi2O3 respectively. The tenth value layer decreased with increasing density; for example, at 0.511 MeV, the layer decreased from 6.886 to 4.887 cm as the density increased from 3.6 to 4.281 g/cm3. The mean free path (MFP) was calculated and compared at 0.284 MeV. The authors found that BBV3 has the smallest MFP (0.997 cm) of the three examined glasses. [ABSTRACT FROM AUTHOR]

The fabrication process of PbO–Bi2O3–ZnO–B2O3(PBZB) glasses involved the application of a melt quenching technique. The glass samples were revealed through X-ray diffraction (XRD) analysis to be amorphous in nature. Fourier-transform infrared (FTIR) spectra, ranging from 4000 to 400 cm−1, exhibited peaks and bands indicating bending and stretching vibrations associated with the constituent groups in the glasses. The Raman spectra indicated that non-bridging oxygens (NBOs) formed with PbO’s incorporation into the network. To investigate the UV–Vis spectra of the glass, the Derivation of Absorption Spectrum Fitting (DASF) method was employed. This analysis predicted a decrease in energy band gap values, which was attributed to the increased presence of NBOs within the glass network. The prepared glasses’ radiation-shielding properties were reported using Phy-X software in the range of 0.284–1.333 MeV, where it was found that the mass attenuation coefficient (MAC) follows the order of PBZB1 < PBZB2 < PBZB3 < PBZB4, which means a positive correlation of the samples’ MAC with the glasses’ PbO content, or an inverse correlation with the glasses’ B2O3 content. Thus, the sample characterized by the highest content of PbO, or the least B2O3 content, has the greatest radiation shielding ability. The ratio between the tenth value layer for the PBZB1 and PBZB4 samples was estimated, with the results demonstrating the ratio to be higher than one, thus indicating that PBZB1’s TVL is always greater than PBZB4’s TVL. From the ratio between the TVL, we found that the addition of PbO causes a reduction in the thickness of the glass that is needed to attenuate the incoming photons. The PBZB4 sample (which contains 70 mol% of PbO) has the greatest advantage over the other materials in the glass system at lower and higher energies, while having a slightly reduced advantage at medium energies. PBZB4 possesses the lowest HVL value, thus qualify as the best shielding material. [ABSTRACT FROM AUTHOR]

This paper reports on the structural, optical and luminescence studies of Dy3+–Eu3+ co-doped glass ceramics that are obtained via thermal treatment method. The initial confirmation on glass ceramics with the formation of NaBSiO4 crystalline phase was made through XRD study. The FTIR study showed the vibrations of network formers (B2O3, SiO2) and other functional groups. The quantity of non-bridging oxygens (NBOs) are increased in the glass ceramics with increase in annealing temperature. The absorption spectra (UV–visible-NIR) showed the possible transitions of Dy3+ and Eu3+ ions in the glass ceramics. A red-shift in the absorption band-edge and reduction in the optical band gap values were obtained for glass ceramics owing to their heating temperatures. Photoluminescence studies showed the excitations of Dy3+ and Eu3+ ions under 575 nm and 613 nm emission wavelengths. The obtained NaBSiO4 crystalline phase in the glass ceramics has enhanced the luminescence intensity, and lifetimes of Dy3+ and Eu3+ ions compared to unheated precursor glass when excited under 350 nm and 393 nm. Color chromaticity diagram and correlated color temperature (CCT) values showed a shift in the color of light from warm white of precursor glass to neutral white of glass ceramics. The overall results justify the possibility of considering the Dy3+-Eu3+ co-doped glass ceramics as efficient materials for solid-state lighting applications like W-LEDs. [ABSTRACT FROM AUTHOR]

Cobalt-doped titania nanocomposites were fabricated to be utilized for radiation shielding aims. The chemical composition of the composites was measured using the energy-dispersive X-ray spectrometer. Moreover, the structure of the composites was evaluated using the X-ray diffractometer, and the morphology of the fabricated composites was presented using the scanning electron microscope. Furthermore, the γ-ray shielding properties were estimated using the Monte Carlo simulation between 0.059 and 2.506 MeV. The linear attenuation coefficient of the fabricated composites decreased by factors of 93% for all samples by raising the incident γ-energy between 0.059 and 2.506 MeV. Moreover, the partial replacement of the Ti4+ by Co3+ slightly enhanced the linear attenuation coefficient from 0.607 to 0.630 cm−1 when the Co3+ increased from 0 to 3.7 wt%. The improvement in the linear attenuation coefficient causes an enhancement in other radiation shielding properties. [ABSTRACT FROM AUTHOR]

The primary objective to develop the high-density glasses have been fulfilled by replacing the TeO2 with Bi2O3 in the Bi2O3–TeO2–CdO glass system in the present work. Samples’ density (ρ) is large enough, ranging from 5.636 g/cm3 to 5.788 g/cm3. Due to the expansion of the network the molar volume (Vm) and oxygen molar volume increases and the oxygen packing density decreases. The elastic characteristics of the resulting glasses diminished with increasing Bi2O3 concentrations in the network structure. The radiation shielding parameters were presented between 0.122 and 1.458 MeV. The transmission factor (TF) for the glasses with thickness of 0.25 cm is around 50% at 0.245 MeV, while for the same glasses with thickness of 0.5 cm, we found that the TF is varied between 20 and 25%. The TF reaches a minimum of about 4–6% when the thickness is 1 cm. The TF data demonstrated that introducing more Bi2O3 into the samples leads to an improvement in the radiation shielding performance of the glasses. The effective atomic number (Zeff) values at 0.245 MeV are equal to 61.74, 63.03, 64.16, and 65.18 for A1–A4, respectively. The average HVL ( HVL ¯ ) results showed that a thin sample less than 0.4 cm thick can be used to shield photons with energies between 0.245 and 0.344 MeV, while a shield with thickness 0.65 to 0.70 cm is needed to attenuate photons with energies between 0.411 and 0.444 MeV. [ABSTRACT FROM AUTHOR]

Development of next-generation photonic device necessitates employing vitreous materials with high optical nonlinearities and low optical limiting thresholds. Additionally, the high nonlinear photonic glasses are suitable for nuclear radiation shielding applications. Herein, the borate-based glass specimens bearing significant amounts of heavy metal oxides (Bi2O3 and PbO) activated with various quantities of Eu2O3 have been explored for optical limiting, nonlinear photonic, and nuclear radiation shielding applications. Efficacy of Eu2O3 content on functional features has been assessed and discussed the outcomes in detail. The open aperture Z-scan results unveiled the enhancement in two-photon absorption coefficient and reduction in optical limiting threshold with Eu2O3 amount in the glass composition. Further, certain fundamental attenuation factors such as mass attenuation and linear attenuation coefficients were estimated utilizing Phy–X software in the energy ranges between 0.284 and 2.506 MeV. The mass attenuation and the linear attenuation coefficients were found to improve with the inclusion of more and more Eu2O3 in the glass compositions. The outcomes of the study clearly revealed that the high Eu2O3 activated lanthanum heavy metal borate glasses are productive in optical limiting, nonlinear optical, and gamma radiation shielding strategies to cutoff the high energy electromagnetic and nuclear radiations. The comparative study further validates that the La2O3–Bi2O3–B2O3–Eu2O3 glasses are more advantageous than La2O3–PbO–B2O3–Eu2O3 glasses. [ABSTRACT FROM AUTHOR]

We developed new composites for photons shielding applications. The composite were prepared with epoxy resin, red clay and bismuth oxide nanoparticles (Bi2O3 NPs). In order to establish which ratio of red clay to Bi2O3 NPs provides the best shielding capabilities, several different ratios of red clay to Bi2O3 NPs were tested. The transmission factor (TF) was calculated for two different thicknesses of each sample. From the TF data, we found that epoxy resin materials have a high attenuation capacity at low energy. For ERB-10 sample (40%Epoxy + 50% Red clay + 10% Bi2O3 NPs), the TF values are 52.3% and 14.3% for thicknesses of 0.5 and 1.5 cm (at 0.06 MeV). The composite which contains the maximum amount of Bi2O3 nanoparticles (40%Epoxy + 50% Red clay + 10% Bi2O3 NPs, coded as ERB-30) has lower TF than the other composites. The TF data demonstrated that ERB-30 is capable of producing more effective attenuation from gamma rays. We also determined the linear attenuation coefficient (LAC) for the prepared composites and we found that the LAC increases for a given energy in proportion to the Bi2O3 NPs ratio. For the ERB-0 (free Bi2O3 NPs), the LAC at 0.662 MeV is 0.143 cm−1, and it increases to 0.805 cm−1 when 10% of Bi2O3 NPs is added to the epoxy resin composite. The half value layer (HVL) results showed that the thickness necessary to shield that photons to its half intensity can be significantly lowered by increasing the weight fraction of the Bi2O3 NPs in the epoxy resin composite from 0 to 30%. The HVL for ERB-20 and ERB-30 were compared with other materials such as (Epoxy as a matrix material and Al2O3, Fe2O3, MgO and ZrO2 as filler oxides in the matrix at 0.662 MeV. The HVL values for ERB-20 and ERB-30 are 4.385 and 3.988 cm and this is lower than all the selected epoxy polymers. [ABSTRACT FROM AUTHOR]

Rare earth (RE)–doped glasses with high quantum efficiency and strong photoluminescence (PL) characteristics are essential for next generation photonic and optoelectronic devices. To attain strong PL emission and related attributes of Er3+-doped in glass system, the silver nanoparticles (NPs) were embedded. UV-Vis absorption and microscopic measurements divulged the existence of metallic silver NPs. The PL emission of Er3+-doped in titled glasses was improved in visible and infrared spectral ranges as AgNO3 concentration escalated to higher level. In addition, the quantum efficiency also enhanced as the AgNO3 doping level escalated to a higher level. The enhancements in PL emission intensity and quantum efficiency were ascribed to the local field induced by surface plasmons of Ag NPs. The outcomes suggest that the high concentration of Ag NPs routed in Er3+-doped glass system is useful in fabricating the optical amplifiers and solid-state lasers. [ABSTRACT FROM AUTHOR]

Concentrations of heavy metal oxide i.e. Sb2O3 varying from 10 to 40 mol% (in increments of 10 mol%) were loaded into a 20Na2O–80B2O3 transparent glass system to study the efficacy of Sb2O3 nonlinear optical (NLO) and gamma radiation shielding features of glasses. The NLO characteristics were ascertained by a Z-scan technique with 532 nm pumping in nanosecond laser pulse regime. The role of non-bridging oxygens, Sb3+, and Sb5+ ions in the enhancement of optical nonlinearities was examined. The two-photon absorption coefficient increased from 0.42 to 1.36 cm/GW with the increasing Sb2O3 substitution for B2O3, and the magnitude of optical limiting threshold followed an opposite behavior from 1.5 × 109 to 0.8 × 109 J/cm2. The linear attenuation coefficients (LACs) values at 0.4111 MeV increased from 0.215 cm−1 at 2.28 g/cm3 to 0.379 cm−1 at 3.98 g/cm3. The half-value layers (HVLs) were at a minimum when the energy was at its lowest and at a maximum when the energy was at its highest. The reported HVL trend indicates that the glasses must be as much as thicker to attenuate the same number of photons at higher energy. The NLO and radiation shielding features suggest that the high-Sb2O3 glass can be used to fabricate laser and nuclear radiation protection glasses. [ABSTRACT FROM AUTHOR]

The lanthanum sodium borate glass of composition xSm2O3-yAgCl-(80-x-y)B2O3–15 Na2O-5La2O3 (where x = 0.5 and y = 0.1 mol %) was prepared and heat treated at a constant temperature of 450° C with different annealing schedules of 10, 20 and 30 h durations to enable the formation and growth of the Ag nanoparticles. Transmission electron microscope measurements revealed the existence of Ag nanoparticles in the examined glass specimen. The strong red emission was observed for 4G5/2 → 6H7/2 inherent transition of samarium ions in the titled glass samples. The robust emission and excitation intensities of Sm3+ ions are at 10 h annealing durations, and then decrease with increasing annealing durations due to the quenching effect. The transition and radiative properties of various excited levels of Sm3+ in the titled glass series were estimated, including the branching ratios, stimulated emission cross-section, radiative lifetime, and radiative transition probabilities. The improved luminescence results and better JO features for the 4G5/2 → 6H7/2 emission transition suggest the glass specimens routed with Ag nanoparticles are beneficial for optoelectronic and photonic applications. [ABSTRACT FROM AUTHOR]

Efficacy of silver nanoparticles concentration and annealing durations on optical limiting and optical nonlinearities of borate based glasses bearing the composition (79.5–x)B2O3–15Na2O–5La2O3–0.5Sm2O3–xAgCl (mol%) was assessed by Z-scan approach under the pumping of visible light (532 nm) in nanosecond regime. The dual photon absorption parameter (α2) was elevated from 0.576 × 10−11 to 1.201 × 10−11 m/W with AgCl content from 0 to 0.5 mol%. This α2 further raised to 1.964 × 10−11 m/W when the optimized glass host heat treated at 450° C for 25 h. Similarly, the index of nonlinear refraction (n2) was enhanced from 1.642 × 10−19 to 2.532 × 10−19 m2/W as the AgCl content increased from 0 to 0.5 mol%. This n2 value in turn monotonously increased to 2.963 × 10−19 m2/W when optimized glass system annealed at 450° C for 25 h. The optical limiting threshold magnitude followed reverse trend compared to α2 and n2. The enhancement in nonlinear optical features and optical limiting efficiencies were related to field stimulated by Ag0 nanoparticles when excited with high energy radiation. However, the non-uniform local field generated when the glass nanocomposites heated for longer duration resulted the switching of nonlinear absorption. The nonlinear optical and optical limiting results infer the 0.5 mol% AgCl encompassing glass sample annelaed at 450 °C for 25 h is benificail for construction of power optical limiters to operate in the visible range. [ABSTRACT FROM AUTHOR]

A series of six samples were prepared based on the chemical composition of 65B2O3 + 20ZnO + (15-x)LiF + xSnO2 (where x = 0, 0.25, 0.5, 0.75, 1, and 1.25 mol%) to study the role of SnO2 on enhancing the optical and radiation attenuation capacity of the prepared glasses. The preparation of the glass series was performed using the melt quenching method at 1100 °C for 60 min. The density of the fabricated samples was measured using an MH-300A densimeter. The optical parameters of the fabricated glasses were calculated based on the spectrum recorded by a Cary 5000 UV–Vis–NIR double beam spectrophotometer in a wavelength range of 200 to 3000 nm. Furthermore, Monte Carlo simulation code and the XCOM online database were used to estimate the gamma-ray shielding capacity of the fabricated samples from 0.244 to 2.506 MeV. The results show enhanced gamma-ray shielding capacity due to the replacement of LiF by SnO2. The linear attenuation coefficient at 0.244 MeV was enhanced from 0.352 to 0.389 cm−1. The half-value thickness of the investigated glasses decreased from 1.967 to 1.784 cm when the increasing addition of SnO2 from 0 to 1.25 mol%. [ABSTRACT FROM AUTHOR]

In this paper, series of perovskites ceramics (CaTiO3, BaTiO3–SrTiO3) added with 1.0 wt.% of tin oxide SnO2 were fabricated through the solid-state reaction process. The different specimens' structural and functional groups examinations were investigated by using X-ray and Fourier transform infrared spectrophotometer (FTIR) techniques. The surface morphology and elemental composition were examined by scanning electron microscope (SEM) with energy dispersive X-ray analysis (EDX). The XRD peaks of CaTiO3 and BaTiO3–SrTiO3 were indexed to the orthorhombic and cubic perovskites, respectively. The inclusion of tin oxide into the prepared ceramics caused shifting in the position of the peaks towards higher angles resulting in deformation in the crystal structure of the ceramics. FTIR results confirmed the formation of the desired compositions. The average grain size increased upon the addition of ton oxide into CaTiO3 and BaTiO3–SrTiO3 ceramics. In addition, the radiation shielding performances were examined. The results showed that the addition of SnO2 to the CaTiO3 and BaTiO3–SrTiO3 ceramics enhances the shielding properties of these ceramics. The linear attenuation coefficient (LAC) at a gamma photon energy of 0.015 MeV enhanced from 72.186 to 73.115 cm−1 when the SnO2 increase from 0 to 1 wt.% for samples CTO and CTO@SnO2, respectively. In this regard, the LAC coefficient of BTO–STO is 168.813 cm−1, and it is enhanced by adding 1 wt.% of SnO2 to be 171.004 cm−1 for sample BTO–STO@SnO2. The results also illustrate a decrease in the ceramics half-value layer and the gamma-ray transmission factor with the addition of the SnO2 in the ceramic matrix. The results obtained validate the possibility of applying the manufactured ceramics for radiation protection purposes. [ABSTRACT FROM AUTHOR]

The present work explores the glass system of (50 + x)PbO–5BaO–5WO3–10Na2O–(30−x)B2O3 (x: 0, 5, 10, 15, and 20 mol%) for radiation shielding applications. For this purpose, five distinct glass systems (PbBaW50–PbBaW70) have been fabricated via conventional melting technique. The fabricated glass series was then investigated in terms of physical, mechanical, and photon shielding properties. According to the physical determinations, the glass density increases from 5.22881 to 6.50914 g.cm−3 as the PbO ascends from 50 to 70 mol%. On the other hand, the change of the PbO concentration in the respective samples affects the mechanical properties (Makishima and Mackenzie model) due to the change in composition and density of the samples. That is, the values of Young's, Bulk, Shear, and Longitudinal moduli are nearly the same with the slight decreasing trend for all the moduli, respectively, as the PbO increases. Further, the Poisson's ratio decreases from 0.179 to 0.171 while the value of fractural bond connectivity ranges from 3.516 to 3.624, and the hardness increases from 2.195 to 2.252 GPa with the increase in PbO concentration. For radiation shielding features, the Phy-X/PSD computations revealed that linear attenuation coefficient (LAC)@0.3029 MeV were equal to 1.627, 1.770, 1.921, 2.062, and 2.223 cm−1 for PbBaW50 to PbBaW70 samples, respectively. By considering LAC determinations, other significant parameters such as mass attenuation coefficient, half-value layer, tenth-value layer, mean free path, and effective atomic number were evaluated. As a result of these findings, one can report that the increasing doping rate of PbO leads to achieving more-performanced radiation shielding materials. [ABSTRACT FROM AUTHOR]

In the the present work, we discussed in detail the X-ray shielding behavior of the glasses in the composition of TeO2-Li2O-GeO2-ZnO-Bi2O3 for the energy range of 30.82–303 keV. Some essential radiation shielding parameters have effectively been evaluated via EPICS2017 library. EPICS2017 showed a relative change between 0.67%—8.23% from the Phy-X software mass attenuation coefficient (MAC) calculations. According to the findings, one can report that the linear attenuation coefficient (LAC) was enhanced for all photon energies owing to the insertion of 15 mol% Bi2O3. From these results, the authors evaluated the thickness variations by finding the half-value layer (HVL), and it was seen that BiTe1 was equal to 0.323 cm while BiTe2 to BiTe4 were equal to 0.221, 0.172, and 0.144 cm in the respective order, at 0.1606 MeV. Similarly, the tenth-value layer (TVL), mean free path (MFP), and effective atomic number (Zeff) were improved by far the best via sample-BiTe4 (highest Bi2O3 concentration). [ABSTRACT FROM AUTHOR]

The kinetics of hydrogen atom abstraction from methyl propionate (MePr), a biodiesel model, by •H and •CH3 radicals, have been studied. Here, we employ density functional theory (BB1K, BMK, M06-2X, M08-HX, and ωB97XD) and ab initio (MP2, CBS-QB3, and G3) calculations. Rate coefficients of each of six-bimolecular reaction pathways of MePr oxidation were calculated using the conventional transition state theory (TST) with Eckart (Eck) tunneling correction over a wide temperature range, 700-1600 K at pressure 1.0 atm. Branching ratios analysis of different reaction channels indicates that abstraction of H atom from Cα is the most dominated route for MePr fuel consumption. However, rate constants of H-atom abstraction from the terminal methyl groups increase with rising of temperature for both •H and •CH3 radicals. [ABSTRACT FROM AUTHOR]

We prepared a series of sodium phosphate glasses by changing WO3/P2O5 content and investigated structure optical and radiation shielding features as a function of the glass composition. The average density ( ρ exp )was found to increase gradually from 2.49 to 3.07 g/cm3, while the average molar volume values reduced from 47.37 to 44.28 cm3/mol with WO3 addition. Also, the average field strength was also computed and found to increase with increasing WO3. The study of optical absorption spectra reveals that the absorption peaks in the visible region become higher compared to the peaks In the Ultraviolet region. This observation is accompanied by a color transformation of glasses from light to dark blue color, with more WO3 adding. The existence of a pentavalent tungsten state (W5+) is identified by this blue color; with WO3 addition an absorption band at around 350–390 nm is appeared. Moreover, this band is overlapped with the Urbach edge, which regularly produces an artificial edge-like feature at ~ 400 nm. A detailed deconvolution protocol is required for an appropriate understanding of these spectra and unraveling the hidden Urbach edge. Our analysis shows that, with increasing WO3/P2O5 content, the optical band gap decreases. This behavior can be elucidated in terms of a lower band gap of WO3 (2.7 eV) than that of P2O5 (8.5 eV) and the high polarizing power tungsten. Further, the radiation shielding parameters were investigated for the prepared glasses. WO3 addition improves these shielding parameters against radiation. Besides, upon the increase of WO3 concentration, the linear attenuation coefficient of glass material increases, which leads to decrease in have value layer values. Then it is deducible that the amount of WO3 in this glass sample has an important impact on the shielding capability at lower energy values and has a slight impact at higher energy values. [ABSTRACT FROM AUTHOR]

The current paper studied the (95-y)P2O5–yBi2O3–5Nb2O5 glass systems where y = 10, 12.5, 15, and 17.5 mol% using EPICS2017 data library to understand the radiation shielding characteristics. The investigated glass systems, PNbBi1 to PNbBi4, were evaluated in terms of linear attenuation coefficient (LAC), mass attenuation coefficient (MAC), half-value layer (HVL), tenth-value layer (TVL), mean free path (MFP), and effective atomic numbers (Zeff) at the energy levels of 20, 40, 60, 80, and 100 keV. According to the theoretical computations, Bi2O3 ensured to improve LAC parameter in all photon energies; hence, PNbBi4 can be regarded as the best. Further, we reported that a nearly 14% increase in glass density leads to improve MAC parameters against ascending photon energies. PNbBi4 can be regarded as the lowest thickness ensuring sample at all photon energies amongst the other samples with respect to HVL and TVL parameters. Moreover, inserting Bi2O3 provided lower MFP thicknesses which in turn develops better radiation shielding characteristics. We found out that Zeff shows an increasing trend as the Bi2O3 increases, but displays a decreasing trend as the photon energy increases. Additionally, a comparison of shielding properties using the EpiXS and Phy-X/PSD has been evaluated. It was figured out that there is a good agreement observed between the results of each library. The results in most energies were found to be in good agreement with low (< 1%) relative differences. Overall, the authors concluded that the Bi2O3-reinforced PNb series can be utilized in X-ray shielding applications with satisfactory performance. [ABSTRACT FROM AUTHOR]

This study aims to study the radiation shielding features of TeO2–WO3–RO systems (where RO =PbO and Bi2O3). The glasses were theoretically evaluated by using the simulation code Phy–X/PSD. Four TeO2–WO3–Bi2O3 glasses and three TeO2–WO3–PbO glasses were tested in this study. The linear attenuation coefficient (LAC), mass attenuation coefficient (MAC), effective atomic number (Zeff), half value layer (HVL), tenth value layer (TVL), and mean free path (MFP) of the glasses were calculated and analyzed. WTeBi3 and WTeBi4 have the greatest LAC and MAC values at all energies, while WTePb1 had the least LAC and MAC values. At 0.347 MeV, the MAC of the glasses is equal to 0.115 0.117, and 0.107 cm2/g for WTeBi3, WTeBi4, and WTePb1, respectively. The Zeff of the glasses decreased and increased based on the photon interaction phenomena present in low, medium, and high energy ranges. WTeBi2 has the greatest HVL, equal to 2.070 cm and 2.594 cm at 1.333 and 2.506 MeV, respectively, while WTeBi3 has the least, 1.943 cm and 2.532 cm for the same energies, respectively. The TVL values followed the order of WTePb1 < WTePb2 < WTeBi2 < WTePb3 < WTeBi1 < WTeBi3 < WTeBi4 at both the tested energies. The greatest MFPs were observed at the greatest selected energy, 2.506 MeV. The TeO2–WO3–Bi2O3 glasses and TeO2–WO3–PbO glasses were compared against each other and with some other radiation glasses to determine the most effective attenuator. [ABSTRACT FROM AUTHOR]

Detection and qualification process related to impurities assume importance in pharmacological drug development programs, and the present article gives the structural and spectral characterization of sulfone derivatives their self-assembly with graphene sheets theoretically. The investigation of adsorption behavior of sulfone compounds can provide valuable information about its reactivity and electronic and structural properties. Three-dimensional electrostatic potential diagrams were mapped. The frontier orbital energies and energy bandgaps of the molecules were computed. Delocalization of charge density between the bonding or lone pair and antibonding orbitals calculated by NBO analysis. Docking was executed to investigate binding areas of chemical compounds. Bioactivity scores show that the pharmacokinetic and pharmacological properties of the ligands are appropriate leading to be considered potential drug agents. The obtained theoretical wavenumber results of the present study were fully compatible with the experimental results. Graphical abstract [ABSTRACT FROM AUTHOR]

Cocrystals are of immense applications in crystal engineering and pharmaceutical chemistry. Hydrochlorothiazide is found to form cocrystals with picolinamide (H1), tetramethylpyrazine (H2) and piperazine (H3). It was characterized using IR spectra, and quantum mechanical calculations for geometry and other properties. Frontier orbital energies are used to predict the energy properties and model the possible charge transfer between the constituents of the cocrystal. The frontier molecular orbital analysis indicates chemical reactivity and bioactivity of the cocrystals. The MEP surface reveals the various reactive surfaces in the cocrystal system, which is very important in deciding various biological activities. The UV-Vis spectra show the possible electronic transitions of the molecules. Simulated electronic spectra using TDDFT method with CAM-B3LYP functional were used to investigate the suitability of the cocrystals to be used in DSSC. Moreover, the molecular docking analysis proves that the cocrystals can act as potential inhibitors and paves the way for developing effective drugs. [ABSTRACT FROM AUTHOR]

Spectroscopic analysis and different quantum mechanical studies of four pharmaceutically active compounds phenacetin, p-acetanisidide, 4′-butoxyacetanilide, and 4′-(3-chloropropoxy)acetanilide are reported in this manuscript. Simulated IR spectrum of these compounds was compared with experimentally available data, and essential functional group assignments were made. We also report the frontier orbital properties and other derived local energy descriptors which talks about the relative stability and reactivity. Photovoltaic efficiency of the compounds was studied from the simulated electronic spectra. The compound was found to interact with graphene and fullerene, to form molecular self-assembly. These self-assemblies showed tremendous enhancement in various physicochemical properties when compared with its constituents. The nature of the interactions between studied chemical species was discussed with the help of chemical reactivity principles. Biological activity of the compounds was predicted using molecular docking studies. It is interesting to see that on adsorption with a graphene/fullerene surface, all adsorbed complex shows enhancement in the Raman activity giving surface enhanced Raman spectra (SERS). This can be used for the detection of these drugs in a pharmacological or biological sample. Interestingly the graphene/fullerene drug molecular assembly shows enhanced biological activity when compared with individual drug molecules. [ABSTRACT FROM AUTHOR]