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This paper presents the results of the combined study of the thermoluminescence (TL) and electron paramagnetic resonance (EPR) properties of La-doped CaF 2 (CaF 2 : La) phosphor. X-ray diffraction (XRD) results confirmed that CaF 2 has been successfully synthesized. Scanning electron microscopy (SEM) results and energy dispersive spectrometer (EDS) spectra show that the synthesized phosphor is pure and has a good overall morphology. The glow curve of CaF 2 : La phosphor shows an emission band between 230 and 500 nm centered at 340 nm. The Tm-Tstop method and the deconvolution technique were used to find the number of overlapping TL peaks in the 50–300 °C region and their kinetic parameters. A linear dose-response curve was obtained for the range 1–9 Gy, with the onset of a slight supralinear behavior for doses higher than 9 Gy. Gamma-irradiated CaF 2 : La phosphor has been studied using the technique of EPR to identify the defect centers and also to infer the centers involved in the TL process. Thermal annealing studies indicate the presence of three defect centers. One of the centers (center I) is identified as the O 2 − ion and is characterized by an axial g -tensor with principal values g ∥ = 2.013 and g ⊥ = 2.0053. This center correlates with the TL peak at 200 °C. Center II with an isotropic g -value of 2.0005 is attributed to an F center and also relates to the 200 °C TL peak. The third center (center III) is assigned to an F center. [ABSTRACT FROM AUTHOR]

Archaeometry had a slow start in the study of Amazonian and Caribbean ceramics, practiced almost exclusively by professionals outside of the archaeology discipline, primarily geologists, physicists and chemists, but is now slowly gaining track among archaeologists. In this paper, we summarize the archaeometric research done in the last thirty years in ceramics from the Amazon and Caribbean regions, emphasizing its main questions, aims and future developments for archaeometry in Latin America. Archaeometric studies are a growing field of research and improve understanding of past networks, technological knowledge and cultural traditions. [ABSTRACT FROM AUTHOR]

Mg 1−x O:Bi x (x = 0.01–0.5 mol%) nanophosphors have been prepared using the solution combustion method and subsequent annealing at 1173 K in air. Rietveld refinement on X-ray diffraction (XRD) data confirmed the rock-salt phase formation in pure and Bi3+ doped MgO (space group; F m ‾ 3 m). Lower Bi3+ ion concentrations in Mg 1−x O:Bi x (x = 0.01 and 0.05 mol%) lead to tensile strain and increased lattice parameters of MgO. Higher doping concentrations of Bi3+ ions (x = 0.1–0.5 mol%) lead to a decrease in the lattice strain, unit cell parameters, and Mg–O bond length. Transmission electron microscopy (TEM) images along with selected area electron diffraction (SAED) patterns confirmed the crystalline nature of Mg 1−x O:Bix samples with an average particle size of ∼37.5 nm. X-ray absorption spectroscopy (XAS) results at the Mg K-edge and Bi L-edge confirmed the Mg2+ ions and Bi3+ ions in Mg 1−x O:Bi x samples throughout the Bi doping range. O–K edge XAS conveys the hybridization of the frontier orbitals of O and Bi atoms. UV–visible absorption spectroscopy measurements convey the defect-induced absorption peak shifting in Mg 1−x O:Bi x compounds. Dopant and host defect-assisted PL emission is observed, with prominent emission in the blue region owing to the transition between 3P 1 to 1S 0 and 3P 0 to 1S 0 of Bi3+. The quenching effect on PL properties has been observed beyond 0.05 mol% doping of Bi3+ ions. The presence of various defect states and their stability with re-trapping and charge transfer behaviour have been analyzed by thermoluminescence studies of gamma-irradiated samples, which enable the Mg 1−x O:Bi x samples for potential applications in display device dosimetry. [ABSTRACT FROM AUTHOR]

This study explored the relationship between transformational leadership (TL) and job satisfaction (JS) in the hospitality sector in Delta State, Nigeria. The study employed survey research designs to enable the researcher generate primary data from the study respondents in order to ascertain the link between the studies constructs. In order to test the study hypotheses, 124 questionnaires were administered to the study respondents out of which 112 were properly filled and returned. Both correlation and multiple regression analysis were utilised in this study for data analysis via stata. Findings showed that the metrics of TL (idealise influence and inspirational motivation) have a substantial positive relationship with JS. The study then recommended that leaders/management/managers should motivate, inspire, believe in the opinions of employees and create a healthy and profitable relationship with employees. This is because good attention and relationships from the leaders/management/managers to subordinates (employees) can improve employee JS and help employees feel like an important part of the organisation. [ABSTRACT FROM AUTHOR]

Presently, the world is progressing towards the notion of smart and secure cities. The automatic recognition of human activity is among the essential landmarks of smart city surveillance projects. Moreover, classifying group activity and behavior detection is complex and indistinct. Consequently, behavior classification systems reliant on visual data hold expansive utility across a spectrum of domains, including but not limited to video surveillance, human-computer interaction, and the safety infrastructure of smart cities. However, automatic behavior classification poses a significant challenge in the context of live videos captured by the smart city surveillance system. In this regard, the use of pictures with pre-trained convolution neural networks (CNNs)-assisted transfer learning (TL) has emerged as a potential technique for deep neural networks (DNNs) object detection., resulting in increased performance in localization for smart city surveillance. Against this backdrop, this paper explores various strategies to develop advanced synthetic datasets that could enhance accuracy when trained with modern DNNs for object detection (mAP). TL was employed to address the limitation of DL that necessitates a huge dataset. The KITTI datasets were used to train a contemporary DNN single-shot multiple box detector (SSMD) in TensorFlow. A variety of metrics were employed to assess the efficacy of the novel automated Transfer Learning (TL) system within a real-world context, specifically designed for object detection within the DL framework (referred to as OD-SSMD). The results unveiled that this developed system outperformed preceding investigations, demonstrating superior performance. Notably, it exhibited the remarkable capability to autonomously discern and pinpoint various attributes and entities within digital images, effectively identifying and localizing each item present within the images.

Thoracolumbar (TL) fractures are uncommon in children. While surgical treatment is recommended for unstable TL fractures, there is no consensus on appropriate surgical treatment. We present a case series of pediatric patients with traumatic TL fractures treated with minimally invasive techniques. We discuss our early experience and technical challenges with navigation and robotic-assisted fixation. A retrospective review of a prospectively maintained trauma database from February 2018 to February 2023 of all pediatric patients (<18 years old) undergoing percutaneous fixation for unstable TL fractures was performed. Minimally invasive techniques included fluoroscopy and/or navigation-guided or robotic-assisted surgery. Clinical course, radiographic findings, and technical challenges were reviewed. A cohort of 12 patients (age range, 4–17 years) with 6 (50%) Chance fractures, 2 (16%) pars fractures, 2 (16%) pedicle fracture, 1 (8%) burst fracture, and 1 (8%) other fracture were identified. Nine patients had fractures involving the lumbar spine, and the remaining 3 had thoracic fractures. In all cases, percutaneous pedicle screws were placed above and below the fracture with the use of neuronavigation or robotic-assisted navigation (n = 2). Blood loss was <30 mL for single-level fractures and instrumented fusion. Two patients had hardware-related complications. At follow-up (mean 9.67 months after surgery), patients were doing well clinically, and most imaging showed stable alignment. Our early experience shows that short segment instrumentation through a minimally invasive approach is a safe and effective surgical option for young pediatric patients with good clinical outcomes and favorable radiographic postoperative finding. [ABSTRACT FROM AUTHOR]

Zinc selenide doped with Sn and (Sn, Dy) phosphors has been prepared by firing the samples in an atmosphere of nitrogen gas. The voltage and frequency dependence of electrolyte brightness has been studied. Voltage dependence of electroluminescence (EL) brightness reveals an acceleration collision mechanism in the Schottky barrier at the metal–semiconductor interfaces. EL and photoluminescence (PL) spectra and thermoluminescence (TL) glow curves of these phosphors have also been recorded to understand the nature and mechanism involved in the luminescence process. The trapping parameters are calculated for the glow curves of these phosphors. [ABSTRACT FROM AUTHOR]

In this study, Zn 2-x La x SiO 4 (x = 0.00, 0.02, 0.04, and 0.06) materials with varying weight percentages of lanthanum (La) in zinc silicate (Zn 2 SiO 4) were synthesized using the sol-gel process. The effect of La dopant on the structure, morphology, and optical characteristics of Zn 2 SiO 4 was investigated through various analytical and spectroscopical techniques. According to PXRD measurements, La3+ ions were incorporated into the host materials of Zn 2 SiO 4 , considerably affecting their crystallinity. Irregular granular and pebble stone-like morphology was observed in the FESEM analysis. The optical energy bandgap of La-doped Zn 2 SiO 4 materials decreased from 5.09 eV to 3.80 eV while increasing the La dopant into Zn 2 SiO 4 host systems. The photoluminescence (PL) spectra and photoluminescence quantum yield (PLQY) confirmed the increase of luminescent peak intensity at 730 nm. A tri-exponential fitting technique was used to determine the luminescence decay lifetime of the significant emissions of La-doped Zn 2 SiO 4 , and the average lifetime was found to be 30.4 ns. Dosimetry could benefit significantly from the thermoluminescence investigation conducted for the La-doped Zn 2 SiO 4 phosphor at a linear heating rate of 8 °C/s. [ABSTRACT FROM AUTHOR]

Deep learning-based methods have been proven excellent performance in detecting pornographic images/videos flooded on social media. However, in a dearth of huge yet well-labeled datasets, these methods may suffer from under/overfitting problems and may exhibit unstable output responses in the classification process. To deal with the issue we have suggested an automatic pornographic image detection method by utilizing transfer learning (TL) and feature fusion. The novelty of our proposed work is TL based feature fusion process (FFP) which enables the removal of hyper-parameter tuning, improves model performance, and lowers the computational burden of the desired model. FFP fuses low-level and mid-level features of the outperforming pre-trained models followed by transferring the learned knowledge to control the classification process. Key contributions of our proposed method are i) generation of a well-labeled obscene image dataset GGOI via Pix-2-Pix GAN architecture for the training of deep learning models ii) modification of model architectures by integrating batch normalization and mixed pooling strategy to obtain training stability (iii) selection of outperforming models to be integrated with the FFP by performing end-to-end detection of obscene images and iv) design of TL based obscene image detection method by retraining the last layer of the fused model. Extensive experimental analyses are performed on benchmark datasets i.e., NPDI, Pornography 2k, and generated GGOI dataset. The proposed TL model with fused MobileNet V2 + DenseNet169 network performs as the state-of-the-art model compared to existing methods and provides average classification accuracy, sensitivity, and F1 score of 98.50%, 98.46% and 98.49% respectively. [ABSTRACT FROM AUTHOR]

Technology impacts human life in both the aspects such as positive and negative, which helps in better communication and eliminating geographical boundaries. However, social media and mobile devices may lead to severe health conditions such as sleep problems, depression, obesity, etc. A systematic review is conducted to analyze health issues by tracking food intake by considering positive aspects using Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) Guidelines. The major scientific databases (such as Web of Science, Scopus, and IEEE explore) are explored to search the image recognition and analysis articles. The search query is applied to the databases using keywords like "Food Image," "Food Image Classification," "Nutrient Identification," "Nutrient Estimation," and using "Machine Learning," etc. 771 articles are extracted from these databases, and 56 are identified for final consideration after rigorous screening. A few investigations are extracted based on available food image datasets, hyperparameters tuning, a technique used, performance metrics, and challenges of Food Image Classification (FIC). This study discusses different investigations with their proposed FIC and nutrient estimation solution. Finally, this intensive research presents a case study using FIC and object detection techniques to estimate nutrition with food image analysis. [ABSTRACT FROM AUTHOR]

Thallium (Tl) compounds, highly toxic to biology, are usually released into flue gas during fossil/minerals combustion, and further distributed in water and soil. In this work, we fundamentally investigated the capture of gaseous Tl2O by industrial V2O5–WO3/TiO2 catalyst under working condition in Tl-containing flue gas. Experimental and theoretical results indicated that the Tl2O has significant electron-feeding capacity and easily donate electron to unoccupied orbitals of TiO2, leading to dismutation of Ti 2p and inartificial formation of p–n junction on TiO2 surface, which prompted Tl2O selectively interacted with TiO2 in flue gas. Herein, we proposed and verified an effective way to capture gaseous Tl2O, which offered almost the best choice to eliminate Tl emission from flue gas and expanded the function of the TiO2-based catalyst. The formation of p–n junction on commercial V2O5–WO3/TiO2 catalyst under working condition was revealed for the first time, which can be a valuable reference for both heterocatalysis and electro/photocatalysis.

"MODI lipi" is one of the ancient scripts of Western India. Considerable work has been reported for various other ancient Indian languages except for MODI lipi. Its structural characteristics and non-availability of image database make MODI recognition challenging. The work reported in this paper comprises the creation of an image dataset for MODI handwritten characters and the development of a supervised Transfer Learning (TL)-based classification framework. It makes use of Deep Convolutional Neural Network (DCNN) Alexnet as a pre-trained network to transfer weights to retrain the network. This network is used as a feature extractor to extract features from different layers of the network. A Support Vector Machine (SVM) is trained on activation features to obtain classifier models. These models are investigated further for recognition accuracy and feature analysis. Subjective and objective measures are used to select discriminant deep features. We achieved recognition accuracies of 92.32% and 97.25% for Handwritten MODI character recognition and handwritten Devnagari character recognition, respectively. [ABSTRACT FROM AUTHOR]

Aiming at the characteristic that the performance of insulated gate bipolar transistor (IGBT) degrades gradually with time under thermal stress, the time series prediction algorithm in deep learning was applied to IGBT fault prediction, a new fault prediction method based on gate recurrent unit (GRU) and principal components analysis-transfer learning (PCA-TL) was proposed. The method was taken the collector emitter voltage (VCE) as the decay parameter, and was used GRU model to construct the mapping relationship between decay parameter and fault time. The PCA technology was used to synthesize IGBT fault indicators with different distribution characteristics, and TL method was introduced. By fine tuning the parameters of GRU prediction model, the migration from source domain to target domain was completed, and the fault prediction of target domain samples was realized. The experimental results show that the fault prediction model based on GRU has higher prediction accuracy and faster training speed than long short term memory (LSTM) algorithm; PCA-TL method can realize the fault monitoring task of similar devices under different working conditions. The feasibility and correctness of the proposed method are verified. [ABSTRACT FROM AUTHOR]

In this research, the microparticles of alpha alumina doped with dysprosium were synthesized by the solid-state method. The following were used to investigate the structure, size, shape, and chemical composition of particles: X-ray diffraction, scanning electron Microscopy, and energy dispersive spectrometer. The maximum thermoluminescence response to the gamma rays of the 60Co source was obtained in 0.5 mol% of the dysprosium dopant. A computer program based on general-order kinetics was used to determine the number of peaks in the thermoluminescence radiation curve and the kinetic parameters related to each peak. The T m –T Stop method was applied to estimate the number of overlapping peaks in the thermoluminescence glow curve. The fabricated sample has a linear thermoluminescence response up to 1000 Gy. Other dosimetric properties of these microparticles were also investigated. [ABSTRACT FROM AUTHOR]

This study presents an investigation carried out in the European University of the Atlantic, Santander. Its main aim was to create a didactic proposal to improve reading comprehension in the subject of English as a Foreign Language, level 2. This propo sal included the use of reading strategies and graphic organizers. Eleven texts from the textbook Macmillan English Hub B1+/ B2- were analyzed. The activities were improved by including a training in the use of reading strategies and a specific graphic organizer for every type of text. To apply the proposal, it was necessary to take a previous and a post reading test as well as 5 extra reading activities as part of the continuous evaluation. The application had to be adapted to online teaching because of the Covid-19 pandemic. The sample of the study consisted of 57 students enrolled in the Science of Sports degree and the Psychology degree. Thirty-one of these students took part in the experimental group, while the other 26 took part in the control group. The results showed that there were significant differences between these two groups. In conclusion, the use of reading strategies together with the training in the use of graphic organizers contributes to an improvement in reading comprehension. [ABSTRACT FROM AUTHOR]

BeO is another luminescent phosphor with very deep traps (VDTs) in its matrix that could not be stimulated using either thermal or conventional optical stimulations. The present study attempts to stimulate these traps using thermally assisted optically stimulated luminescence (TA-OSL), a combination of simultaneous thermal and optical stimulation that is applied to the material following a thermoluminescence measurement up to 500 °C. An intense, peak-shaped TA-OSL signal is measured throughout the entire temperature range between room temperature and 270 °C. This signal can be explained as the transfer of charges from VDTs to both dosimetric TL traps. Experimental features such as the peaked shape of the signal along with the presence of residual TL after the TA-OSL suggest that recombination of TA-OSL takes place via the conduction band. Isothermal TA-OSL is not effective for extending the maximum detection dose thresholds of BeO, unlike minerals such as quartz and aluminum oxide. Nevertheless, TA-OSL could be effectively used in order to either (a) control the occupancy of VDTs, circumventing the intense sensitivity changes induced by long-term uses and high accumulated dose to the VDTs, or (b) measure the total dose accumulated over a series of repetitive dose calculations. [ABSTRACT FROM AUTHOR]

The Tibetan Plateau (TP) is known as the water tower of Asia, and the water quality has long been a focus of public concern, especially in the Yarlung Tsangpo River Basin (YTRB), a unique area that is climate-sensitive, geologically complex, eco-fragile, and densely populated. Thallium (Tl) is a typical metal that is more toxic than Pb, Cd, and As and often occurs in sulfide minerals. Although large-scale polymetallic sulfide mineralization developed in the YTRB, the geochemical dispersion and potential risk of Tl in aquatic environments of the YTRB remain poorly understood. In this study, the concentration, distribution, source, and health risk of Tl and associated metal(loid)s in the hot springs and surface water in the YTRB were systematically analyzed. The results showed that the trace elements (Cd, Cr, Zn, Cu, Al, Sr, Ni, Co, Mn, Pb) in water environments are within the recommended limits, except for Tl and As. Principal component analysis (PCA) and correlation analysis (CA) showed that the elements of Tl and As were positively related to each other in either both hot spring water and surface water, indicating their common origin. Spatial variations suggested that high levels of Tl and As observed in the north YTRB, which may be relevant to the reduction–dissolution of Tl (As)-bearing minerals and the magmatic hydrothermal system formed in the shallow part of the northern YTRB. Furthermore, source apportionment identified natural sources of Cu, Ni, Cr, Co, Mn, Zn, and Cd and anthropogenic inputs of Al and Pb. Exposure assessment studies have found that ingestion is the primary route of As and Tl exposure to local population, and balneological and bathing purposes do not constitute a human health concern. This study offers valuable insights into the risk of naturally occurring Tl enrichment being hidden in As-rich hydrosphere in the YTRB and other regions with similar geoenvironmental contexts. [ABSTRACT FROM AUTHOR]

BACKGROUND The quality of rapeseed and the degree of heavy metal pollution are directly related to human health. Monitoring the content of toxic elements such as As, Sb, Cd, and Tl in rapeseed is helpful for early monitoring of raw materials for edible oil production. OBJECTIVES To avoid the cumbersome pretreatment of strong acid digestion, quickly determine the accurate content of volatile toxic elements such as As, Sb, Cd, and Tl in rapeseed, and to solve the challenge of pretreatment due to the heavy fat content of grains, oils, and foods. METHODS A suspension-emulsion synergistic sample preparation technique was used to investigate conditions affecting suspension-emulsion, and a homogeneous and stable slurry-emulsion solution (SES) system was prepared. In the electrothermal vaporizer (ETV) with high sampling efficiency, the temperature-programmed parameters and the dosage of improver palladium nitrate were all optimized. SES was directly injected, and inductively coupled plasma-mass spectrometry (ICP-MS) was used to determine As, Sb, Cd and Tl. RESULTS The overall reproducibility (relative standard deviation, RSD) of the suspension-emulsion sampling-ETV-ICP-MS detection method were 10.1%, 8.8%, 8.9% and 6.4% [c=0.5% (m/V), n=5] for As, Sb, Cd and Tl, respectively. Under the optimum conditions, the limits of detection (3σ) were 40.0ng/L, 20.0ng/L, 50.0ng/L and 10.0ng/L for As, Sb, Cd and Tl, respectively. Accordingly, the limits of detection for the original solid samples were 8.0ng/g, 4.0ng/g, 10.0ng/g and 2.0ng/g for As, Sb, Cd and Tl, respectively. The contents of As, Sb, Cd and Tl in tested rapeseed samples were 50.4-90.5ng/g, 28.0-59.9ng/g, 51.3-69.1ng/g and 91.3-216.6ng/g, respectively. CONCLUSIONS The suspension-emulsion synergistic treatment of rapeseed with high oil content is simple, fast, and cost efficient. It utilizes the advantages of ETV sampling and promotes the application of ETV-ICP-MS solid sampling analysis.

Leukocyte telomere shortening reflects stress burdens and has been associated with cardiac events. However, the patient-specific clinical value of telomere assessment remains unknown. Moreover, telomere shortening cannot be inferred from a single telomere length assessment. The authors investigated and developed a novel strategy for gauging leukocyte telomere shortening using autologous cardiac atrial referencing. Using multitissue assessments from 163 patients who underwent cardiovascular surgery, we determined that the cardiac atrium-leukocyte telomere length difference predicted post-operative complexity. This constituted the first evidence that a single-time assessment of telomere dynamics might be salient to acute cardiac care.

Manganese and cerium doped potassium chloride (KCl:Mn and KCl:Ce) were produced by the co-precipitation method with ultrasonic waves. Characterization of the samples material was carried out using X-ray diffraction (XRD), scanning electron microscope (SEM), and energy dispersive spectrometer (EDS) patterns. The optimum amount of manganese and cerium concentration with the most thermoluminescence (TL) sensitivity was obtained at 0.3 mol% in KCl:Mn and 0.5 mol% in KCl:Ce samples. To evaluate the number of component glow peaks and the kinetic parameters of the TL glow curve of synthesized materials, computerized glow curve deconvolution (CGCD) and Tm-Tstop methods were used. The thermoluminescence properties of phosphors were studied at different doses. The TL response was linear in the range of 10–1000 Gy. Other TL features of the prepared material are also discussed. [ABSTRACT FROM AUTHOR]

In this paper, an ultrathin linearly polarized transmission line (TL) based on tilted microstrip spoof surface plasmon polaritons (SSPPs) is proposed. The proposed structure of the TL consists of an ultrathin corrugated metallic strip with periodic tilted groove arrays and metallic ground. Compared with the reported traditional SSPPs, the proposed SSPPs structures with tilted grooves can support the SSPPs wave with a larger propagation constant, which means a stronger field confinement in the microstrip SSPPs structure and effectively lower the dimension in transverse direction of the TL. Besides, the simulation demonstrates that the wave confinement performance can be well maintained when the grooves tilt from 0 to 60°, and the electric field vectors of the tilted grooves undergo a rotation correspondingly, resulting in a flexible polarization. Therefore, the polarization of different angles can be easily realized when the proposed SSPPs is employed as radiating or feeding structure. To verify characteristic of the proposed structure at microwave frequencies, we simulate, fabricate and measure a back‐to‐back transition sample with 45°‐titled grooves. Both simulations and measured results have clearly validated the good characteristic of the proposed designs. [ABSTRACT FROM AUTHOR]

Infrared-stimulated luminescence (IRSL) emission and its characterisation are reported for the first time for HfO 2 synthesised by the precipitation method and its electron spin resonance (ESR) centres properties are shown in this study. IRSL spectrum has a broad emission band in the blue region, which is centred at about 2.49 eV. A similar emission was observed for the radiofluorescence (RF) with a band centred at 2.52 eV. RF signal intensity decreases with the readout temperature, which might indicate a thermal quenching process. IRSL signal is strongly affected by the readout temperature, as part of its emission is related to the presence of shallow traps (<100 °C). The IRSL shine-down curve is composed of two components with decay times of 15.7 and 800 s, and photoionisation cross-section values of about 1.20 × 10−19 and 2.35 × 10−21 cm2, respectively, based on IRSL carried out at 100 °C after 2 Gy of beta irradiation dose, using a general-order kinetic model. Dosimetric analyses indicated that there is a reproducible signal in IRSL, with a coefficient of variation lower than 9 % for repeatability and 3 % for reproducibility measurements. The dose-response curve has a linear trend in the dose range of 0.3–2.0 Gy. Regarding the photon energy study, it shows an overresponse for photo energy values below 200 keV. Fading of about 40 % after one day of storage was observed. Bleaching measurements indicated that the TL peaks located between 100 and 250 °C share the same trap levels as the IRSL ones. In addition, a possible charge transference is observed from the peak at 330 °C to lower temperature peaks. ESR analyses identified that oxygen vacancies of V+ type in a four-coordinated arrangement are induced by irradiation and are temperature-sensitive. Based on the bleaching and ESR measurements, it is reasonable to infer that V+ type vacancies are likely responsible for the IRSL, and its blue emission. • First characterisation on HfO 2 IRSL emission. • IRSL and RF spectral measurements: the blue emission of HfO 2. • Deconvolution study on the IRSL and its dosimetric properties. • ESR centres: oxygen vacancies of V+ type and correlations to the IRSL signal. [ABSTRACT FROM AUTHOR]

A study on retrospective dosimetry was performed using electronic personal dosimeters (EPDs) for reconstructing doses received by radiographic testing workers. The dosimetric properties of the thermoluminescence (TL) peak in the temperature range of 100–200 °C were investigated by measuring the TL of the resistors extracted from the EPDs in a darkroom environment. Results showed that this TL peak exhibited optimal dosimetric properties, with a minimum detectable dose as low as 13 mGy. To calculate the absorbed dose using the resistors, a simplified single aliquot regenerative (SAR) dose method using the TL peak was employed. The zero dose of the commercial EPD (model CLOVER) was determined to be 58 ± 72 mGy through the random selection of six EPDs. Additionally, a dose overestimation correction factor for compensating rapid sensitivity changes after TL measurement of the natural sample was calculated as 1.73 ± 0.09. Furthermore, it was observed that the TL signal faded exponentially to approximately 60% over a period of 12 weeks. Subsequently, retrospective dosimetry was performed by irradiating EPDs with a standard gamma ray dose of 1 Gy. The radiation exposure dose calculated from the TL peak of the resistors was found to be approximately 10% lower. These findings showed that the retrospective dosimetry with EPD can be utilized for accurately estimating the radiation exposure dose. • Retrospective dosimetry was performed using resistors in electronic personal dosimeters. • The thermoluminescence dosimetric properties of resistors were investigated. • Electronic personal dosimeters are potentially suitable for retrospective dosimetry. [ABSTRACT FROM AUTHOR]

This study focuses on the use of MgB 4 O 7 :Dy,Na dosimeters in mammography measurements. The reproducibility measurement and dose-response curves were studied for the characterization of dosimeters. Next, variation in entrance surface dose (ESD) and mean glandular dose (MGD) was investigated according to different glandularity/adipose tissue ratios of 30%/70%, 50%/50% and 70%/30% for fixed anode and variable filter combinations (Mo/Mo, Mo/Rh) using BR-12 phantoms with thicknesses from 2 to 6 cm. The ESD and MGD values increased at varying rates with increasing phantom thicknesses and glandularity ratios. The increase rate in MGD is ∼30% for both Mo/Mo and Mo/Rh for the difference between (70%/30%) and (50%/50%), considering the thickness of 6 cm. On the other hand, the MGD value obtained for a glandular ratio of 70%/30% at 6 cm for Mo/Mo is ∼40% higher than that for Mo/Rh. A proportional comparison of MGD differences obtained according to glandularity and filter changes may provide valuable contributions to the literature. Within this study, it was shown that MgB 4 O 7 :Dy,Na dosimeters can be used as new alternative dosimeters in the field of mammography to perform ESD and MGD measurements. In further studies, MgB 4 O 7 :Dy,Na dosimeters can be used to determine the various organ doses, such as eye and thyroid, resulting from the scattered radiation dose using rando phantoms. • Entrance surface dose (ESD) and mean glandular dose (MGD) were determined by using MgB 4 O 7 :Dy,Na dosimeters. • The variation of ESD and MGD was investigated for different glandularity/adipose tissue ratios and phantom thicknesses. • The dose-response curves of MgB 4 O 7 :Dy,Na dosimeters were generated in mammography. [ABSTRACT FROM AUTHOR]

Retrospektif (geriye dönük) dozimetri, doz ölçümünün planlanmadığı durumlarda doz hesabı için kaza dozimetresinin önemli araçlarından biridir. Kaza dozimetrisi, radyasyon kazası sonucu dışarıdan/ içten maruz kalan insanların radyasyon dozunun çeşitli dozimetri yöntemleri ile değerlendirilmesidir. Kaza bölgesindeki herhangi bir obje doğal dozimetre olarak değerlendirilebilmektedir. Şimdiye kadar seramik ya da porselen ürünleri, yapı malzemeleri, elektronik bileşenler (IC parçaları, sim kart, transistörler), saat camı ve telefon ekranı gibi birçok malzeme bu amaçla incelenmiştir. Bu çalışmada çevrede yaygın şekilde bulunan çeşitli porselen ve kil bazlı malzemelerin (şekerlik, kül tablası, sigorta porseleni, cila maddesi içerikli ve içeriksiz yapay diş porseleni, seramik tırnak törpüsü, namaz mühürü ve kumbara) retrospektif dozimetri amaçlı kullanımı için numune hazırlanma sürecinin TL sinyalinin üzerinde etkisi, radyasyon kazasından önce malzemenin maruz kalmış olduğu sıcaklığın (örneğin yangın) OSL sinyali üzerinde etkisi, termal sönümlenme, farklı uyarma modlarında OSL lüminesans sinyalinin değişimi gibi özellikleri de araştırılmıştır. Ayrıca bir radyasyon kazası senaryosu gerçekleştirilerek araştırılan materyaller ile TL ve OSL tekniğini kullanılarak kaza dozu hesaplanmıştır. Elde edilen sonuçlara göre incelenen bütün numunelerin radyasyon kazası durumunda retrospektif doz hesaplaması için birer dozimetrik malzeme olarak kullanılabilirliği ortaya çıkmaktadır. Kaza senaryosu sonucunda numunelerden TL yöntemi ile hesaplanan kaza doz değerlerini kaza mahallinde konulmuş TLD100’ler ile elde edilen değerlerle kıyasladığımız zaman kumbara ve yapay diş porseleni numunelerinden

There is now extensive theoretical and empirical literature on the place of the first language (L1) and the second language (L2) in the foreign language (FL) classroom. Although this body of work includes related teacher beliefs and practices, less attention has been paid to the factors that may influence these practices across different national contexts. Through an extensive survey of secondary school teachers of a FL in Spain and England we investigated teachers' reported L1/L2 practices and the possible influence of pre-service training on these practices. We found that teachers in England reported greater use of the L1 than teachers in Spain across virtually all language functions. In both groups there was no evidence of the influence of advocated teaching approaches within pre-service training courses on teachers' reported L1 and L2 use. Differences in teachers' reported practices seem to be better explained by contextual factors influenced by and derived from national policy and the social value of the L2. [ABSTRACT FROM AUTHOR]

Lung cancer is among the most hazardous types of cancer in humans. The correct diagnosis of pathogenic lung disease is critical for medication. Traditionally, determining the pathological form of lung cancer involves an expensive and time-consuming process investigation. Lung cancer is a leading cause of mortality worldwide, with lung tissue nodules being the most prevalent way for doctors to identify it. The proposed model is based on robust deep-learning-based lung cancer detection and recognition. This study uses a deep neural network as an extraction of features approach in a computer-aided diagnosing (CAD) system to assist in detecting lung illnesses at high definition. The proposed model is categorized into three phases: first, data augmentation is performed, classification is then performed using the pretrained CNN model, and lastly, localization is completed. The amount of obtained data in medical image assessment is occasionally inadequate to train the learning network. We train the classifier using a technique known as transfer learning (TL) to solve the issue introduced into the process. The proposed methodology offers a non-invasive diagnostic tool for use in the clinical assessment that is effective. The proposed model has a lower number of parameters that are much smaller compared to the state-of-the-art models. We also examined the desired dataset's robustness depending on its size. The standard performance metrics are used to assess the effectiveness of the proposed architecture. In this dataset, all TL techniques perform well, and VGG 16, VGG 19, and Xception for 20 epoch structure are compared. Preprocessing functions as a wonderful bridge to build a dependable model and eventually helps to forecast future scenarios by including the interface at a faster phase for any model. At the 20th epoch, the accuracy of VGG 16, VGG 19, and Xception is 98.83 percent, 98.05 percent, and 97.4 percent. [ABSTRACT FROM AUTHOR]

BACKGROUND: The quality of rapeseed and the degree of heavy metal pollution are directly related to human health. Monitoring the content of toxic elements such as As, Sb, Cd, and Tl in rapeseed is helpful for early monitoring of raw materials for edible oil production. OBJECTIVES: To avoid the cumbersome pretreatment of strong acid digestion, quickly determine the accurate content of volatile toxic elements such as As, Sb, Cd, and Tl in rapeseed, and to solve the challenge of pretreatment due to the heavy fat content of grains, oils, and foods. METHODS: A suspension - emulsion synergistic sample preparation technique was used to investigate conditions affecting suspension - emulsion, and a homogeneous and stable slurry - emulsion solution (SES) system was prepared. In the electrothermal vaporizer (ETV) with high sampling efficiency, the temperature - programmed parameters and the dosage of improver palladium nitrate were all optimized. SES was directly injected, and inductively coupled plasma - mass spectrometry (ICP - MS) was used to determine As, Sb, Cd and Tl. RESULTS: The overall reproducibility (relative standard deviation, RSD) of the suspension - emulsion sampling - ETV - ICP - MS detection method were 10.1%, 8.8%, 8. 9% and 6. 4% [ c =0. 5% ( m/V), n = 5 J for As, Sb, Cd and Tl, respectively. Under the optimum conditions, the limits of detection ( 3CT) were 40. 0ng/L, 20. 0 ng/L, 50.0ng/L and 10.0ng/L for As, Sb, Cd and Tl, respectively. Accordingly, the limits of detection for the original solid samples were 8.0ng/g, 4.0ng/g, 10.0 ng/g and 2.0ng/g for As, Sb, Cd and Tl, respectively. The contents of As, Sb, Cd and Tl in tested rapeseed samples were 50. 4 - 90. 5 ng/ g, 28.0 - 59. 9ng/ g, 51. 3 - 69.1 ng/g and 91. 3 -216. 6ng/g, respectively. CONCLUSIONS: The suspension - emulsion synergistic treatment of rapeseed with high oil content is simple, fast, and cost efficient. It utilizes the advantages of ETV sampling and promotes the application of ETV - ICP - MS solid sampling analysis. [ABSTRACT FROM AUTHOR]

Thallium (Tl) is a toxic trace element with a highly negative effect on the environment. For phytoextraction purposes, it is important to know the limitations of plant growth. In this study, we conducted experiments with a model Tl-hyperaccumulating plant (Sinapis alba L., white mustard) to better understand the plant tolerance and/or associated detoxification mechanisms under extreme Tl doses (accumulative 0.7/1.4 mg Tl, in total). Both the hydroponic/semi-hydroponic (artificial soil) cultivation variants were studied in detail. The Tl bioaccumulation potential for the tested plant reached up to 1% of the total supplied Tl amount. Furthermore, it was revealed that the plants grown in the soil-like system did not tolerate Tl concentrations in nutrient solutions higher than ~1 mg/L, i.e., wilting symptoms were evident. Surprisingly, for the plants grown in hydroponic solutions, the tolerable Tl concentration was by contrast at least 2-times higher (≥ 2 mg Tl/L), presumably mimicking the K biochemistry. The obtained hydroponic/semi-hydroponic phytoextraction data can serve, in combination, as a model for plant-assisted remediation of soils or mining/processing wastes enriched in Tl, or possibly for environmental cycling of Tl in general.

Thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) properties of quartz samples extracted from soil of Fisher Island (76° 13ʹ 23.9ʺ E, 69° 23ʹ 31.9ʺ S) in Antarctica were studied. The nature of signals indicated presence of a dominant slow component in the OSL signal. The widely utilized Single Aliquot Regenerative (SAR) protocol for dose recovery was found unsuitable for this particular sample due to the dominating slow component in the OSL signal. Efforts to minimize the effect of slow component in dose recovery by adopting procedures like, bleaching with blue light, and early background subtraction were carried out. Additionally, thermally transferred OSL (TT-OSL) studies were conducted on the natural sample and dose estimation using the TT-OSL SAR protocol was carried out. • TL/OSL properties of quartz extracted from sediments collected from Fisher Island, Antarctica. • OSL dating using SAR protocol. • Thermal transferred OSL SAR protocol. • Limitations of using quartz extracted from Antarctica sediments for OSL dating. [ABSTRACT FROM AUTHOR]

Abstract Two types of materials were sampled as part of an investigation of the relics of the Holy Catholic Church of the Apostles St Philip and St James in the Basilica dei Santi Apostoli in Rome: bone- and mummy-materials and architectural samples. The analyses encompassed radiocarbon dating, thermoluminescence dating, gas and liquid chromatographic separation with mass spectrometric detection, X-Ray fluorescence, X-Ray diffraction, inductively coupled plasma mass spectrometry, Raman spectroscopy, and Fourier transform infrared spectroscopy. The results show that the samples were subjected to a number of conservational and exhibition-related treatments. The alleged femoral bone of St James was dated between AD 214 and 340 (2σ confidence), which shows that this cannot be the bone of St James. An encrustation found in a canal in the reliquary in the high altar construction showed the presence of heavily oxidized rapeseed oil, which was radiocarbon dated between AD 267 and 539 (2σ confidence), and a ceramic shard also found in the high altar construction was TL-dated to AD 314–746 (2σ confidence). The two latter dates are consistent with a translation of the relics following the erection of the church at the time of Pope Pelagius I in AD 556–561.

[Display omitted] • BC-SIPN particles selectively adsorb TlOH (aq) , easing Tl concentration dependence. • Hydrogen bonding-electrostatic interactions formed between TlOH (aq) and BC-SIPN. • SIPN enhances particle stability, extending lifetime for sustained efficacy. • Electro-induction directly oxidizes Tl(I) to Tl(III) by BEC on BC-SIPN particles. • Gel-minerals with 0.073 % Tl content exhibit recycling potential. Electrochemical techniques for thallium (Tl) treatment face a substantial challenge linked to the concentration of Tl(I), hindering the efficient removal and recovery of trace Tl(I) (μg L−1). In response, we synthesized hydrogel particles incorporating biochar (BC) within semi-interpenetrating polymer networks (SIPN), showcasing robust selectivity for Tl(I). These biochar-embedded-SIPN hydrogel particles (BC-SIPN particles), employed as dispersed electrodes, facilitated the targeted oxidation and enrichment of Tl(I) through electro-induction. Research outcomes elucidate the adept mitigation of the "efficiency-dependent concentration" behavior by electro-induced BC-SIPN particles during the reaction process. Under optimized conditions (pH 12, 2 V cm−1, 30 min), Tl(I) removal efficiency surpassed 98 % at an initial concentration of 100 μg L−1. The SIPN structure enhanced particle stability, and after seven cycles of enrichment in a 100 μg L−1 Tl(I) environment, BC-SIPN particles achieved a Tl content of 0.073 %, meeting Tl mineral content standards and promoting the recovery of scarce Tl resources. First-principles calculations underscore the pivotal role of hydrogen bond-electrostatic interactions between TlOH (aq) and particles in driving selective Tl(I) adsorption. Insights from quenching and capture reactions reveal a predominant direct oxidation pathway of Tl(I) to Tl(Ⅲ), complemented by indirect oxidation driven by reactive oxygen species, including OH, O- 2 and 1O 2. This study presents an innovative approach for trace Tl(I) wastewater treatment, simultaneously mitigating the "efficiency-dependent concentration" phenomenon, and underscores the transformative potential of electro-induced BC-SIPN hydrogel particles in offering sustainable solutions for Tl(I) removal and resource recovery in environmental stewardship. [ABSTRACT FROM AUTHOR]

Zebrafish are an outstanding model for assessing the involvement of genes in paediatric cataracts. Gene discovery for cataracts is enhanced by manipulation of the genome of zebrafish embryos and comparing the phenotypes of mutant progeny with the wildtype embryos. However, wildtype laboratory fish can also develop cataracts, potentially confounding the results. In this study, we compared the baseline cataract rate between two commonly used wildtype laboratory strains, AB and TL, and also an outbred transgenic line with mCherry reporter. We assessed a total of 805 lens images of fish at 4 days post-fertilisation for cataracts and scored each cataract observed as mild, moderate or severe. We found that the AB strain had a cataract rate of 16.2%, TL had 8.9%, and mCherry had 0.7% and these rates were significantly different. We found that TL strain had a lower rate of mild cataracts than AB fish, however, the rate of moderate and severe phenotypes in the AB and the TL strain was similar. Overall, we showed that the baseline cataract rate varies significantly between the strains housed in a single facility and conclude that baseline rates of cataracts should be assessed when planning experiments to assess the genetic causes of cataracts. [ABSTRACT FROM AUTHOR]

The present study presents the effect of heat treatment on TL and EPR of dumortierite. It was found that applying a heat treatment at 1200 °C for 1h, followed by slow cooling to room temperature, is optimal for improving its TL sensitivity. The glow curves of the sensitized dumortierite sample show TL emission bands centered at 350, 475, and 580 nm. The kinetic parameters of the TL peaks were obtained using the Tm-Tstop and deconvolution methods. In addition, sensitized dumortierite exhibits a linear response with γ-radiation dose and low fading in its TL response. Studies using the technique of EPR were carried out to investigate the defect center EPR signals observed after γ-irradiation. A single defect center with an axially symmetric g -tensor was observed with principal values g ∥ = 2.0009 and g ⊥ = 2.0017. The center was attributed to an F+ center and appears to correlate with the TL peak at 200 °C. [ABSTRACT FROM AUTHOR]

BeO is another luminescent phosphor with very deep traps (VDTs) in its matrix that could not be stimulated using either thermal or conventional optical stimulations. The present study attempts to stimulate these traps using thermally assisted optically stimulated luminescence (TA-OSL), a combination of simultaneous thermal and optical stimulation that is applied to the material following a thermoluminescence measurement up to 500 °C. An intense, peak-shaped TA-OSL signal is measured throughout the entire temperature range between room temperature and 270 °C. This signal can be explained as the transfer of charges from VDTs to both dosimetric TL traps. Experimental features such as the peaked shape of the signal along with the presence of residual TL after the TA-OSL suggest that recombination of TA-OSL takes place via the conduction band. Isothermal TA-OSL is not effective for extending the maximum detection dose thresholds of BeO, unlike minerals such as quartz and aluminum oxide. Nevertheless, TA-OSL could be effectively used in order to either (a) control the occupancy of VDTs, circumventing the intense sensitivity changes induced by long-term uses and high accumulated dose to the VDTs, or (b) measure the total dose accumulated over a series of repetitive dose calculations.

Background: Higher infliximab trough levels (TLs) correlate with better clinical, inflammatory, and endoscopic outcomes among inflammatory bowel disease (IBD) patients. Although standard scheduled infliximab therapy regimen consists of infusions at pre-defined time-points (weeks 0, 2, 6, and every 8 weeks), short-period deviations from therapeutic schedule are common in 'real life', but the pharmacokinetic impact of these deviations has not been explored. In this study, we aim to determine whether short-period deviations from infusion schedule affect infliximab-TL. Methods: A retrospective analysis of all IBD patients receiving infliximab maintenance therapy every 8 weeks was conducted in a tertiary medical center. Patients with anti-drug antibodies, deliberate interval shortening and <3 sequential maintenance sera available were excluded. Associations between time since last infusion and TL were studied. Statistical analysis was performed using generalized estimating equations. Results: Out of over 10,000 sera, 2088 sera of 302 maintenance period stable infliximab-therapy-patients met inclusion criteria (median TL 4.1 μg/mL, interquartile range (IQR) 2.3–6.5 μg/mL). A delay beyond 3 days in infusion schedule (n > 59 days since last infusion) was found to significantly affect TL (mean difference in TL 0.9 μg/mL, 95% confidence interval (CI): 0.03–1.9 μg/mL, p < 0.04). Furthermore, among patients with delayed infusions, 80% had TL below 5 μg/mL, in comparison to 55% of patients who were not late (odds ratio (OR): 2.81, CI: 2.02–3.92, p < 0.0001). Conclusion: Real-life delays of ⩽3 days from infusion protocol can probably be allowed. Delays >3 days culminate in measurable decrease of TL, although effect on clinical outcome is unclear. This needs to be taken into account when interpreting drug-level test results. Summary: A total of 2088 sera of 302 maintenance period inflammatory bowel disease (IBD) patients treated with infliximab were analyzed, to assess effect of small deviations from infusion schedule on TLs. A significant decline in patients' trough level (TL) was noted as early as 3 days after scheduled infusion. [ABSTRACT FROM AUTHOR]

Trivalent Dysprosium (Dy3+) activated garnet structured Li 7 La 3 Zr 2 O 12 (LLZO) phosphors were synthesized by conventional solid state reaction method. The phase structure of the prepared Dy3+ doped LLZO powders was confirmed by X-ray diffraction and Raman spectroscopy studies. Field Emission Scanning Electron Microscopy (FESEM) studies indicated a change in morphology and an increase in the area of the intergranular Li–Al–O liquid layer is observed with the increase of Li and dopant concentrations. Composition analysis of the prepared samples was examined by X-ray photoelectron spectroscopy (XPS) analysis. PL emission band observed at 579 nm was assigned to4F 9/2 - 6H 13/2 transition in yellow region under the ultraviolet excitation wavelength of 351 nm. White light emission was confirmed by the Commission Internationale de L'Eclairage (CIE) chromatic coordinate graph. Thermoluminescence studies were carried out and the results indicated that the grown phosphors are suitable for industrial dosimetric applications where high doses are needed to be measured. [ABSTRACT FROM AUTHOR]

CaSiO3 crystals doped with 0.5%, 1.0% and 2.0% Ce were developed using the floating zone method, and the scintillation and thermally-stimulated luminescence (TSL) properties were evaluated. Under X-ray irradiation, the emission peaks due to the 5dâ€"4f transitions of Ce3+ appeared at 360 nm in all the samples. Under 241Am 5.5 MeV α -ray irradiation, a clear full-energy peak appeared in all the samples, and the light yield of the 2.0% Ce doped-sample was 1040 ph/5.5 MeV- α. As a TSL dosimeter, the samples were very sensitive to X-rays and showed a good linear response from 0.1 to 1000 mGy, which was equivalent to the measurable sensitivity of commercial dosimeters for personal dose monitoring. [ABSTRACT FROM AUTHOR]

In many application domains such as medicine, information retrieval, cybersecurity, social media, etc., datasets used for inducing classification models often have an unequal distribution of the instances of each class. This situation, known as imbalanced data classification, causes low predictive performance for the minority class examples. Thus, the prediction model is unreliable although the overall model accuracy can be acceptable. Oversampling and undersampling techniques are well-known strategies to deal with this problem by balancing the number of examples of each class. However, their effectiveness depends on several factors mainly related to data intrinsic characteristics, such as imbalance ratio, dataset size and dimensionality, overlapping between classes or borderline examples. In this work, the impact of these factors is analyzed through a comprehensive comparative study involving 40 datasets from different application areas. The objective is to obtain models for automatic selection of the best resampling strategy for any dataset based on its characteristics. These models allow us to check several factors simultaneously considering a wide range of values since they are induced from very varied datasets that cover a broad spectrum of conditions. This differs from most studies that focus on the individual analysis of the characteristics or cover a small range of values. In addition, the study encompasses both basic and advanced resampling strategies that are evaluated by means of eight different performance metrics, including new measures specifically designed for imbalanced data classification. The general nature of the proposal allows the choice of the most appropriate method regardless of the domain, avoiding the search for special purpose techniques that could be valid for the target data. [ABSTRACT FROM AUTHOR]

In this paper, we present the results of inter-comparison studies on identification of irradiated food carried out by the leading European laboratories from 1991 to 2018. In 1990s, the Federal Institute for Health Protection of Consumers and Veterinary Medicine in Germany played the leading role in the organization of the inter-laboratory tests on this subject. At the beginning of the present century, the Spanish Agency for Food Safety and Nutrition and Food National Spanish Centre took over this role. In total, 47 international tests were carried out in which nearly 500 samples of alimentary products were analysed in 37 laboratories from 14 European countries. The tests were aimed at proving the reliability of analytical methods – thermoluminescence (TL), photostimulated luminescence (PSL), and electron paramagnetic resonance (EPR) spectroscopy – for identification of specific irradiated food products and to control the analytical skills and experience of participating laboratories. The results made possible a discussion on why some irradiated food samples are more difficult for identification. In general, the tests showed that TL measurements of products such as herbs, nuts, peppers, and raisins, and EPR studies of fish and chicken bones, fresh strawberries, and dried fruits could be used as reliable control methods. The challenge that control laboratories are facing now, is related to the identification of complex food products such as diet supplements or biopharmaceuticals, in which only some additives are irradiated. [ABSTRACT FROM AUTHOR]

• Porcelain-based materials were investigated using stimulated luminescence methods. • Luminescence dosimetric properties were examined. • The lowest detectable dose limits (LDDL) of the porcelain-based materials were studied. • Luminescence kinetic parameters of both TL and OSL signals were determined. In the present study, different porcelain-based materials including a sugar bowl, an ashtray, a porcelain breaker, an artificial dental implant, an electric fuse and the seal of a porcelain moneybox were investigated via thermally (TL) and optically stimulated luminescence (OSL). For this purpose, luminescence dosimetric properties such as TL and OSL curve shapes, reproducibility, bleachability, along with dose response features such as linearity and lowest detectable dose limits (LDDL) of these materials were compared. A feature that is sample-dependent deals with both quartz and mullite content of each porcelain paste, as it was indicated by XRD analysis. Three dominant peaks in TL glow curves were ubiquitously observed, and OSL decay curves formed in two components (C 1 and C 2) for all samples. It was determined that the LDDL for only two TL peaks (P1 and P2) seem acceptable for accidental retrospective dosimetry applications (0.9–2.2 Gy). On the other hand, the LDDL values obtained according to OSL analysis yielded more promising results in terms of accidental retrospective dosimetry applications as 0.3–0.4 Gy and 0.75–1.35 Gy for C 1 and C 2 components, respectively. TL peaks P1 and P2 indicate the majority of prevalent, if not universal, properties of stimulated luminescence. This latter universality could support an argument towards identification of these two TL peaks directly correlated to quartz mineral. On the other hand, TL P3 could be attributed to a contribution of more than one mineral, such as quartz, kaolinite and mullite, due to the lack of prevalence over all stimulated luminescence features. [ABSTRACT FROM AUTHOR]

Retrospective dosimetry is one of the important tools of incident dosimetry in unplanned circumstances of dose calculation. Accident dosimetry is the evaluation of the external/internal radiation dose of people exposed to radiation incidents by various dosimetry methods. Any object in the incident area could be used as a natural dosimeter. So far, different materials such as ceramic or porcelain products, building materials, electronic components (IC parts, sim card, transistors), watch glass and phone screen have been studied following this purpose. In this study; the usability of various porcelain-based and ceramic-based materials which are commonly found around is investigated via luminescence methods; the list includes a sugar bowl, an ashtray, an electric fuse, an artificial dental implant with and without polishing material, ceramic nail file, the seal of prayer and moneybox. For retrospective dosimetry purposes, the effects of the sample preparation process on the TL signal is studied. Moreover, the effect of the temperature (for example fire) the material was exposed to before the radiation incident on the OSL signal, thermal quenching, changes in the OSL luminescence signal in different excitation modes are investigated. In addition, with the use of research materials, a radiation incident scenario was directed and the incident dose was measured using the TL and OSL techniques. According to the results, it was found that all examined samples can be used as dosimetric materials for retrospective dose measurement in case of a radiation incident. While comparing the incident scenario dose values calculated by the TL method with the TLD100s placed at the incident scene, it could be concluded that there is a deviation smaller than 10% in the piggy bank and artificial dental porcelain samples. The results obtained from the OSL measurements showed a deviation smaller than 9% in the fuse porcelain sample and a deviation smaller than 14% in the ceramic nail file sample which were more relevant in comparison to the other samples' results. [ABSTRACT FROM AUTHOR]

Despite the fact that Beryllium oxide (BeO) has been suggested by several research groups as an alternative passive radiation detector and dosimetric material, various concerns about supralinear dose response features were raised for both thermoluminescence (TL) and optically stimulated luminescence (OSL) signals of this material. This paper presents a detailed dose response study on BeO, for two different experimental conditions, namely for (i) the TL signal following irradiation at room temperature (RT), 125 and 200 °C and (ii) the CW – OSL signal measured at three different measurement temperatures (RT, 100 and 220 °C), following two different preheating temperatures (Tpre = 100 and 220 °C). The selection of these temperatures is based on the TL glow curve structure for BeO. The analysis was performed using (a) the actual experimental luminescence signals which suffer thermal quenching, and (b) by using the reconstructed luminescence signals, after correcting for thermal quenching. Deconvolution was performed only for the OSL signals. Intense supralinearity features for both TL peaks and OSL components are reported. Reconstruction affects greatly the dose response features of all TL signals, enhancing supralinearity. The dose response linearity coefficient μ of the dominant OSL component C1 is found to be independent of the preheating temperature. This provides a strong argument for the fact that the charge associated with this component originates mainly from the trap responsible for the TL peak 3 in BeO with Tm beyond 300 °C. Based on our experimental results, the supralinearity features of BeO are attributed to competition for free electrons by electron traps. The results of the present study suggest that competition takes place during both the irradiation and heating stages of a dose response experiment in BeO. Finally, preheating at 220 °C and subsequent OSL measurement at 100 °C is highly recommended as the optimum configuration for BeO, not only for roughly linear dose response but also in order to minimize transfer effects.

Thallium (Tl) is a toxic trace element with a highly negative effect on the environment. For phytoextraction purposes, it is important to know the limitations of plant growth. In this study, we conducted experiments with a model Tl-hyperaccumulating plant (Sinapis alba L., white mustard) to better understand the plant tolerance and/or associated detoxification mechanisms under extreme Tl doses (accumulative 0.7/1.4 mg Tl, in total). Both the hydroponic/ semi-hydroponic (artificial soil) cultivation variants were studied in detail. The Tl bioaccumulation potential for the tested plant reached up to 1% of the total supplied Tl amount. Furthermore, it was revealed that the plants grown in the soil-like system did not tolerate Tl concentrations in nutrient solutions higher than ~1 mg/L, i.e., wilting symptoms were evident. Surprisingly, for the plants grown in hydroponic solutions, the tolerable Tl concentration was by contrast at least 2-times higher (= 2 mg Tl/L), presumably mimicking the K biochemistry. The obtained hydroponic/semi-hydroponic phytoextraction data can serve, in combination, as a model for plant-assisted remediation of soils or mining/ processing wastes enriched in Tl, or possibly for environmental cycling of Tl in general. [ABSTRACT FROM AUTHOR]