Investigation of zinc polycarboxylate cement used in dental treatments in terms of retrospective dosimeter.

Zinc polycarboxylate cement is one of the few dental materials that demonstrate true adhesion to tooth structure. It is suitable for use in living organisms without causing harm. Its strong adhesion to teeth and low level of irritancy are two important parameters for the dental applications. In this study, the dosimetry properties of zinc polycarboxylate cement using thermoluminescence (TL) method were investigated and determined the effectiveness of its use as a good dosimeter. According to the results of this study, the sample shows a good TL properties with three main peaks found around 140°C, 220°C and 330°C. It has a wide linear dose response between 72 Gy and 2.3 kGy and good reusability of the TL peak found at 330°C. Unfortunately, the TL peak intensity values are rapidly faded within a short waiting time interval. Zinc polycarboxylate cement, which is frequently used in dental crowns, can be used as a retrospective dosimeter for measuring the amount of radiation in space studies and nuclear accidents due to its wide linear dose-response curve in the high dose region.

Thermoluminescence properties of the rock naturally annealed for thousands of years by flames from the earth's inner layers.

The gas leak in Chimaera near Çirali, Antalya, has been active for thousands of years. It is also known to be the source of the first Olympic flame in the Hellenistic period. The sample taken from the Chimaere seepage annealed for thousands of years was determined to be calcite-magnesian (Ca, Mg)O3 . In this study, thermoluminescence (TL) properties of calcite-magnesian annealed for thousands of years in the fire caused by methane gas were investigated for particle size, dose-response, heating rate, and fading experiments. It exhibits a clear TL glow curve with two distinct peaks positioned at 160 and 330°C, and its shape is not affected by variation in applied dose and reproduciility of experiment. There is a wide linear relationship between TL output and applied dose up to 614 Gy. Although the positions of the TL peaks are stable with the cycle of measurement, a poor reusability was observed in terms of the area under the TL glow curve and peak intensity.

Thermoluminescence in pumice stone collected from the Mediterranean coast.

Pumice is a low-density, light-coloured volcanic rock (igneous rock) formed when the magma from a volcanic eruption is suddenly cooled. It has a porous structure and can be different colours and have different densities. Pumice stone, unlike other rock, does not sink in water because it has a low density. In the present study, the thermoluminescent (TL) dosimetric characteristics, such as the dose-response, TL signal fading as a function of storage time, heating rate, and reusability of pumice collected on the Mediterranean coast were investigated. From this study, it was concluded that the pumice stone showed TL properties with a TL glow curve including an obviously wide peak at ∼200°C. A wide linear dose-response region up to 144 Gy, low fading of the TL signal when it was kept in a dark room for a long time, and poor reusability properties were observed for dosimetry use.

Classification of thermoluminescence features of CaCO3 with long short-term memory model.

Calcium carbonate (CaCO3 ), a mineral commonly found in the Earth's crust, is mainly in the forms of calcite and aragonite. Calcite has the most stable type of thermodynamics at room temperature and ambient pressure. It has wide band gap structure and is of great interest for a wide-range technical and industrial applications due to its physical properties and suitability. In this study, a new method based on the long short-term memory (LSTM) model of deep learning is proposed to classify the thermoluminescence properties such as fading, cycle of measurement, heating rate, and dose-response of CaCO3 . Therefore the thermoluminescence properties of calcite was investigated as a suitable band structure and its coherent data were used to classify the features using a deep learning LSTM model. Experiments were carried out on a dataset consisting of four classes. The accuracy, precision, and sensitivity values of the proposed model obtained were 98.34, 97.90, and 98.56%, respectively. The classification process of the results obtained from the designed model showed good performance.

Thermoluminescence properties of unique Rosso Levanto marble.

This marble extracted from deposits in Elazig in Turkey resembles red meat in appearance and is only found in Elazig. This type of marble has been widely used in the most famous architectural structures and buildings. In this study, the thermoluminescence (TL) properties of a unique marble that originated from Turkey, named Rosso Levanto, were investigated. Two distinct TL peaks were observed at 160°C and around 375°C. Particle size experiments showed that best TL intensity was seen at 200 µm particle size and therefore dose-response, heating rate, cycle of measurement and fading experiments were carried out on powdered samples with a particle size of 200 µm. The findings revealed good linearity in dose-response, observed up to 0.5 kGy. The reproducibility experiment gave good results, but peak intensity decreased by about 40% in first 6 h of storage in a dark room.

Thermoluminescence behavior of basaltic rocks collected in southeastern region of Turkey.

Basalt is well known as an extrusive igneous rock erupts on land by volcanic eruption. It is darker, denser and finer grained compared to the familiar granite of the continents. The study reveals the thermoluminescence properties (TL) of basaltic rocks which collected in southeastern region of Turkey. With this study, the variations of glow curve of the basalt at the different grain sizes, different annealing temperature and different annealing time have been investigated. This study also includes, dose response and heating rate experiments. As a result, the basalt sample shows thermoluminescence properties with a wide peak about 200°C. The best TL sensitivity was observed at samples whose grain size is ~100µm. The basalt sample has a wide TL glow curve. A linearity for the values up to 155Gy and supralinearity between 155Gy and 615Gy in dose response are observed and it reaches to saturation beyond 615Gy. Thermal treatments at higher temperatures decrease the TL sensitivity.