Rhyolite as a Naturally Sustainable Thermoluminescence Material for Dose Assessment Applications

Thermoluminescence characteristics of natural rhyolite have been studied. Dose response at a wide dose range of 0.5–2000 Gy has been determined. Minimum detectable dose and thermal fading rate are evaluated. Glow curve deconvolution is conducted after determining the best read-out conditions. The repeated initial rise (RIR) method is used to detect the overlapping peaks, and a glow curve deconvolution procedure is used to extract the thermoluminescence parameters of rhyolite. According to the findings, rhyolite glow curves show five interfering peaks corresponding to five electron trap levels at 142, 176, 221, 298, and 355 °C, respectively, at a heating rate of 3 °C/s. The obtained kinetic order for the deconvoluted peaks showed mixed-order kinetic. The reported results might be useful to introduce rhyolite as a natural sustainable material for radiation dosimetry applications

Preparation of newly developed porcelain ceramics containing WO3 nanoparticles for radiation shielding applications

We fabricated porcelain ceramics embedded with WO3 nanoparticles (NPs) for radiation shielding applications. The linear attenuation coefficients were experimentally determined to study the efficiency of the manufactured samples against gamma rays. When the thickness increases from 0.5 to 2 cm, there is a reduction in the photon transmission through the ceramics. At 0.662 MeV, the transmission factor for Porc-1 changes from 0.91 (thickness: 0.5 cm) to 0.83 (thickness: 1 cm), and to 0.69 (thickness: 2 cm). From I/I 0 results, we found that attenuation performance is improved as the sample thickness increases. We evaluated the mass attenuation coefficient (MAC) and examined the influence of the concentration of WO3 NPs on the MAC. We found that Porc-5 which contains a greater quantity of WO3 NPs compared to the other samples has the highest MAC. At 0.06 MeV, the HVL (half value layer) for Porc-1 is 1.063 cm, while at 1.333 MeV this increases to 5.247 cm. Meanwhile, for Porc-2, at 0.06 MeV, a thin layer of thickness 0.806 cm is required to shield 50% of the photons, and at 1.333 MeV, the thickness of the layer must increase to 5.058 cm to shield the photons

Rhyolite as a Naturally Sustainable Thermoluminescence Material for Dose Assessment Applications

Thermoluminescence characteristics of natural rhyolite have been studied. Dose response at a wide dose range of 0.5–2000 Gy has been determined. Minimum detectable dose and thermal fading rate are evaluated. Glow curve deconvolution is conducted after determining the best read-out conditions. The repeated initial rise (RIR) method is used to detect the overlapping peaks, and a glow curve deconvolution procedure is used to extract the thermoluminescence parameters of rhyolite. According to the findings, rhyolite glow curves show five interfering peaks corresponding to five electron trap levels at 142, 176, 221, 298, and 355 °C, respectively, at a heating rate of 3 °C/s. The obtained kinetic order for the deconvoluted peaks showed mixed-order kinetic. The reported results might be useful to introduce rhyolite as a natural sustainable material for radiation dosimetry applications

Impact of ZnO Modifier Concentration on TeO2 Glass Matrix for Optical and Gamma-Ray Shielding Capabilities

This study carried out a comparison of the optical and gamma ray shielding features of TeO2 with and without ZnO modifier concentration. Incorporating ZnO into the TeO2 network reduces the indirect band gap from 3.515–3.481 eV. When ZnO is added, refractive indices, dielectric constants, and optical dielectric constants rise from 2.271–2.278, 5.156–5.191, and 4.156–4.191 accordingly. The transmission coefficient and reflection loss are in direct opposition to each other. With increasing ZnO concentration in the selected glasses, the values of molar refractivity and molar polarizability decrease from 18.767–15.018 cm3/mol and from 7.444 × 10−24–5.957 × 10−24 cm3, respectively, while the electronic polarizability rises from 8.244 × 1024–8.273 × 1024, correspondingly. As expected by the metallization values, the glass systems are non-metallic. The linear attenuation coefficients (LAC) of the studied glass samples ensue through enhancing the photon energy range 0.0395–0.3443 MeV. There is a very slow decrease in the LAC from an energy of 0.1218–0.3443 MeV, yet there is a sharp decrease from an energy of 0.0401–0.0459 MeV. According to the obtained values of numerous shielding parameters such as LAC, MAC, HVL, MFP, and Zeff sample, Zn30 has shown the best radiation shielding ability comprising other studied samples

Radiation shielding capability and exposure buildup factor of cerium(iv) oxide-reinforced polyester resins

The radiation shielding characteristics of the polyester resin composites reinforced with cerium(iv) oxide (CeO2) have been studied. The prepared composites were pure polyester–resin (Poly/CeO2-0), 90% per weight polyester resin and 10% CeO2 (Poly/CeO2-10), (Poly/CeO2-30), (Poly/CeO2-50), and (Poly/CeO2-60). The linear attenuation coefficient (LAC) values for the free polyester and polyester samples with CeO2 were experimentally measured compared with the XCOM data. The experimental LAC value was found to be 0.2377 cm−1 at 0.0595 MeV, which is in good agreement with the calculated value of 0.2454 cm−1. Also, for the same sample, the experimental LAC was found to be 0.1034 cm−1 at 0.662 MeV, showing a good agreement with the calculated value of 0.1057 cm−1. The LAC values for the free polyester, Pol/CeO2-30, and Pol/CeO2-60 are 1.43, 31.82, and 107.77 cm−1 at 0.015 MeV, respectively. The big difference in the LAC values between the composite with 0 and 60% CeO2 is evident. The radiation shielding efficiency (RSE) of the polyester with different amounts of CeO2 was experimentally measured at four energy values. Also, we extended the calculation of RSE at other energy values in the range of 0.015–15 MeV). The exposure buildup factor (EBF) values for the free CeO2 sample and the samples with CeO2 are calculated. The EBF is small at low energies, then increases, and attains a maximum value at moderate energy; the EBF shows a decreasing trend with an increase in the energy

Rapid and Sensitive Detection of Severe Acute Respiratory Syndrome Coronavirus 2 in Label-Free Manner Using Micromechanical Sensors

Coronavirus (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been identified as a deadly pandemic. The genomic analysis of SARS-CoV-2 is performed using a reverse transcription-polymerase chain reaction (RT-PCR) technique for identifying viral ribonucleic acid (RNA) in infected patients. However, the RT-PCR diagnostic technique is manually laborious and expensive; therefore, it is not readily accessible in every laboratory. Methodological simplification is crucial to combat the ongoing pandemic by introducing quick, efficient, and affordable diagnostic methods. Here, we report how microcantilever sensors offer promising opportunities for rapid COVID-19 detection. Our first attempt was to capture the single-stranded complementary DNA of SARS-CoV-2 through DNA hybridization. Therefore, the microcantilever surface was immobilized with an oligonucleotide probe and detected using complementary target DNA hybridization by a shift in microcantilever resonance frequency. Our results show that microcantilever sensors can discriminate between complementary and noncomplementary target DNA on a micro to nanoscale. Additionally, the microcantilever sensors’ aptitude toward partial complementary DNA determines their potential to identify new variants of coronavirus. Therefore, microcantilever sensing could be a vital tool in the effort to extinguish the spreading COVID-19 pandemic

Analysis of Optical and Near-Infrared Luminescence of Er3+ and Er3+/Yb3+ Co-Doped Heavy Metal Borate Glasses for Optical Amplifier Applications

For the near-infrared emission, Er3+ and Er3+/Yb3+ co-activated borate based glass hosts were synthesized by the method of melting andquenching. The emission intensity was maximum for 0.5 mol% Er3+ singly activated glass in the near-infrared (NIR) region covering the telecommunication window. The 2 mol% of Yb3+ co-doping enhanced the emission gain cross-section of the glass by two times contrast to 0.5 mol% Er3+ loaded glass. This enhancement shifted to lower spectral regions when P increased from 0 to 1. The effect of Yb3+ loading on the gain cross-section of the Er3+ co-activated glasses was analyzed using the McCumber theory. The results showed that the 0.5Er2Yb glass has a flat gain in the range of 1460–1640 nm, this suggest a lower pump threshold is enough to perform the laser functioning of a 1530 nm band and optical window of telecommunication applications

Uptake prediction of nine heavy metals by Eichhornia crassipes grown in irrigation canals: A biomonitoring approach

The principal objective of this study is to generate mathematical regression equations that facilitate the estimation of the extent to which Eichhornia crassipes (C. Mart.) Solms, water hyacinth, absorbs heavy metals (HMs) into four plant organs (laminae, petioles, roots, and stolons). This study considers the absorption of nine HMs (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn), and the E. crassipes evaluated in this study were located in three irrigation canals in the North Nile Delta in Egypt, with sampling being conducted in both monospecific and homogenous E. crassipes. Samples of both E. crassipes and water were collected on a monthly basis during one growing season. Analysis of the water samples showed that the HM concentrations ranged from 1.1 μg/l for Cd to 2079.8 μg/l for Fe. All HMs were more concentrated in the E. crassipes roots than in any other organ. Typically, there was a significant correlation between the HM levels in the water and the HM levels in the E. crassipes organs. E. crassipes was documented by a bioconcentration factor > 1.0 for all HMs. The translocation factor in this study was <1.0 for all HMs. The t-values that referred to the discrepancies between the measured and predicted values of the HMs in the four E. crassipes organs were not significant. This finding can be considered to be an indication of the goodness of fit with respect to the ability of the equations to forecast HM uptake. Therefore, the developed equations will benefit the prediction of HM uptake by E. crassipes grown in irrigation canals in the Nile Delta. The efficacy of E. crassipes as a metric for gauging the aggregate impact of environmental pollution in water sources and its potential application in biomonitoring are confirmed in this study.Ebrahem M. Eid extends his appreciation to the Deanship of Scientific Research at King Khalid University for funding this work through Research Group Project under grant number RGP.1/60/42. Aljawhara H. Almuqrin acknowledges the support from the Deanship of Scientific Research at Princess Nourah bint Abdulrahman University through the Fast-track Research Funding Programme.Peer reviewe

Dental students’ attitudes and perceptions about intraprofessional collaboration/education

الملخص: أهداف البحث: للتحقيق في مواقف وتصورات طلاب طب الأسنان حول التعاون / التعليم المهني الداخلي (التعليم الداخلي) والتعلم المشترك واستكشاف تأثير التعليم الداخلي على التطوير الشخصي والمهني للطلاب المشاركين. طرق البحث: تم استخدام استبانة مصمم خصيصا في هذه الدراسة المقطعية. تتكون الاستبانة من سبعة عشر سؤالا يستهدف معرفة تصورات الطلاب حول: 1- تفضيل / رأي طلاب طب الأسنان حول التعليم الداخلي؛ 2- خبرة طلاب طب الأسنان حول تأثير التعليم الداخلي على نتائج التعلم والتطوير المهني؛ 3- ملاحظات الطلاب حول أهمية التعليم الداخلي في مختبرات المحاكاة السريرية وإعدادات مكان العمل. قام الطلاب بتقييم كل من العبارات السبعة عشر على مقياس ليكرت من 5 نقاط (النطاق: 1 = لا أوافق بشدة، 5 = أوافق بشدة). النتائج: تم تحليل ما مجموعه 259 استبانة (معدل الاستجابة = 65٪). كان جميع الطلاب على دراية بالتعليم الداخلي في مجال طب الأسنان (متوسط الدرجة = 4.22). فضل الطلاب التعلم التعاوني / المشترك مع زملائهم في الفصل. كان هناك إجماع بين الطلاب حول التأثير الإيجابي للتعليم الداخلي على التعلم المعزز، وتعزيز مهارات الاتصال، وإثراء العلاقات المهنية مع الموظفين الداعمين وكذلك مع المرضى، وتحسين المهارات التحليلية والنفسية الحركية، وفهم المشاكل المعقدة في العيادات، وفهم نقاط القوة والقيود التي تؤدي إلى تحسين الذات وزيادة الكفاءة والإنتاجية. الاستنتاجات: كان للتعليم الداخلي تأثير مقنع وقوي وإيجابي وفقا لتجربة طلاب طب الأسنان المشاركين في الدراسة. يوصى بتصميم منهج موحد ووضع مبادئ توجيهية لـلتعليم الداخلي في مؤسسات طب الأسنان من أجل التفاعل الفعال بين المتعلمين في جميع المراحل. Abstract: Objectives: To investigate dental students’ attitudes and perceptions about intraprofessional collaboration/education (IPC/IPE) and shared learning, and to explore the impact of IPC/IPE on the personal and professional development of participating students. Methods: A custom-designed questionnaire was used in this cross-sectional study. The questionnaire comprised 17 questions targeting to capture the student's perceptions about IPC/IPE using three factors: (1) dental students' preference/opinion about the IPC/IPE; (2) dental students' experience about the impact of IPC/IPE on learning outcomes and professional development; and (3) students' feedback about the significance of IPC/IPE in clinical/clinical simulation labs and workplace setting. The students rated each of the 17 statements on the 5-point Likert scale (range: 1 = strongly disagree to 5 = strongly agree). Results: A total of 259 responses were analysed (response rate = 65%). All students were aware of IPC/IPE in the field of dentistry (mean score = 4.22). The students preferred collaborative/shared learning with their own classmates. There was a consensus among students about the positive impact of IPC/IPE on enhanced learning, enhancement of communication skills, and enrichment of professional relationships with supporting staff as well as with the patients. There was also improved analytical and psychomotor skills, understanding of complex problems in the clinic, and understanding of strengths and limitations leading to self-improvement and increased efficiency and productivity. Conclusion: IPC/IPE had a compelling, powerful, and positive impact according to the experience of the participating dental students. It is recommended that a standardized curriculum be designed and guidelines set for IPC/IPE at dental institutions for effective interactions among students of all stages

Influence of gamma irradiation on photoluminescence and nonlinear optical properties of Eu3+ activated heavy metal borate glasses

Gamma irradiation effect on absorption, photoluminescence (PL), and nonlinear optical (NLO) features of Eu3+ doped heavy metal borate glasses was studied and elucidated in detail. With blue light excitation, the emission intensity of Eu3+ doped glass was monitored with respect to irradiated dose. The PL intensity of the glasses was reduced with a raise in gamma dose rate because of the formation of colour centres. The quality of the emission colour of the pre- and post-irradiated glasses was analysed using 1931 CIE system. The Nonlinear Optical (NLO) features were examined by the Z-scan technique in the near-infrared spectral region and using femtosecond pulse excitation. The NLO attributes were enhanced with increase gamma irradiation dose. These enhancements are ascribed to the development of defects and non-bridging oxygens when irradiated with gamma radiation. The enhancement of NLO coefficients with gamma irradiation dose suggest the high dose irradiated glasses are useful for photonic device applications, particularly for optical limiters