• Journal of Radiation Protection and Research
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• v.34 no.4
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• pp.155-164
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• 2009

In this paper, we used computerized glow curve deconvolution (CGCD) software with several models for the simulation of a TL glow curve which was used for analysis. By using the general approximation plus model, parameters values of the glow curve were analyzed and compared with the other models parameters (general approximation, mixed order kinetics, general order kinetics). The LiF:Mg,Cu,Si and the LiF:Mg,Cu,P material were used for the glow curve analysis. And we based on figure of merits (FOM) which was the goodness of the fitting that was monitored through the value between analysis model and TLD materials. The ideal value of FOM is 0 which represents a perfect fit. The main glow peak makes the most effect of radiation dose assessment of TLD materials. The main peak of the LiF:Mg,Cu,Si materials has a intensity rate 80.76% of the whole TL glow intensity, and that of LiF:Mg,Cu,P materials has a intensity rate 68.07% of the whole TL glow intensity. The activation energy of LiF:Mg,Cu,Si was analyzed as 2.39 eV by result of the general approximation plus(GAP) model. In the case of mixed order kinetics (MOK), the activation energy was analyzed as 2.29 eV. The activation energy was analyzed as 2.38 eV by the general order kinetics (GOK) model. In the case of LiF:Mg,Cu,P TLD, the activation energy was analyzed as 2.39 eV by result of the GAP model. In the case of MOK, the activation energy was analyzed as 2.55 eV. The activation energy was analyzed as 2.51 eV by the GOK model. The R value means different ratio of retrapping-recombination. The R value of LiF:Mg,Cu,Si TLD main peak analyzed as $1.12\times10^{-6}$ and $\alpha$ value analyzed as $1.0\times10^{-3}$. The R of LiF:Mg,Cu,P TLD analyzed as $7.91\times10^{-4}$, the $\alpha$ value means different ratio of initial thermally trapped electron density-initial trapped electron density (include thermally disconnected trap electrons density). The $\alpha$ value was analyzed as $9.17\times10^{-1}$ which was the difference from LiF:Mg,Cu,Si TLD. The deep trap electron density of LiF:Mg,Cu,Si was higher than the deep trap electron density of LiF:Mg,Cu,P.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.11
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• pp.1837-1842
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• 2013

Photostimulated luminescence (PSL) and thermoluminescence (TL) analyses were conducted for the detection of different gamma-irradiated dried fishes (mussel, squid, beka squid, mitra squid, plaice, and saury) at 0, 1, 5 and 10 kGy. For TL analysis, the contaminating silicate minerals were obtained by density separation or acid hydrolysis treatment. PSL determinations indicated that all the non-irradiated samples showed PSL photon counts/60 s (PCs) lower than 700 PCs (negative), but the irradiated mussel sample at 5 and 10 kGy were only possibility identified showing higher than 5000 PCs (positive). Irrespective of sample kinds and methods of mineral separation, all the non-irradiated samples showed TL glow curves in low-intensity with a maximum peak only after $250^{\circ}C$. However, all the irradiated samples produced TL glow curves in high intensity with a maximum peak particularly in the temperature range of 1$150{\sim}250^{\circ}C$. In conclusion, more distinguishable TL results [glow curve, TL ratio ($TL_1/TL_2$)] were obtained from the marker minerals separated by acid hydrolysis rather than density method.

• Korean Journal of Food Science and Technology
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• v.45 no.1
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• pp.8-12
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• 2013

Photostimulated luminescence (PSL) and thermoluminescence (TL) analyses were conducted for the detection of different irradiated dried fishes. All the non-irradiated samples provided PSL counts of lower than 700 (negative: $T_1$). Clear identification of irradiated sample was only possible for irradiated anchovy with PSL counts >5000; however, the results were unsatisfactory (not positive) for irradiated cod, dried filefish, hairtail, and herring samples. The contaminating silicate minerals were obtained by density separation or acid hydrolysis to perform TL analysis, which resulted in a low intensity of TL glow curve with a maximum peak after $250^{\circ}C$ for the non-irradiated samples that are irrespective of their kinds and methods for the mineral separation. The TL glow curves of high intensity with maximum peak in the temperature range of $150-250^{\circ}C$ were observed for all the irradiated samples. However, better results of TL glow curves and particularly of the TL ratio ($TL_1/TL_2$) were obtained when the minerals were separated by a acid hydrolysis method.

• Journal of the Korean Chemical Society
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• v.57 no.1
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• pp.35-39
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• 2013

The chemical bonding and elastic properties of $Ti_2AC$ (A = Ga, Tl) have been investigated by means of extended H$\ddot{u}$ckel tight-binding band structure calculations. The bulk modulus of $Ti_2AC$ decreases as Ga is replaced with Tl at the A sites. This can be understood by considering the relative strength of Ti-A bonds resulting from the different atomic size of 3A-group elements. The analysis of the projected density of states (PDOS) and the crystal orbital overlap population (COOP) for the respective phases shows that Ti-Ga bonds in $Ti_2GaC$ are stronger than Ti-Tl bonds in $Ti_2TlC$.

• Nuclear Engineering and Technology
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• v.53 no.11
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• pp.3759-3763
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• 2021

In this study, 3" × 3" NaI(Tl) detector, which is widely used in gamma spectroscopy, was modeled with FLUKA code, and calculations required to determine the detector's energy resolution were reported. Photon beams with isotropic distribution with 59, 81, 302, 356, 511, 662, 835, 1173, 1275, and 1332 keV energy were used as radiation sources. The photon pulse height distribution of the NaI(Tl) without influence of its energy resolution obtained with FLUKA code has been converted into a real NaI(Tl) response function, using the necessary conversion process. The photon pulse height distribution simulated in the conversion process was analyzed using the ROOT data analysis framework. The statistical errors of the simulated data were found in the range of 0.2-1.1%. When the results, obtained with FLUKA and ROOT, are compared with the literature data, it is seen that the results are in good agreement with them. Thus, the applicability of this procedure has been demonstrated for the other energy values mentioned.

• Ocean and Polar Research
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• v.30 no.4
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• pp.401-406
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• 2008

Early gonadal development and sexual differentiation of dark-banded rockfish (Sebastes inermis Cuvier) were followed from parturition to 400 days post parturition (dpp). During this period, average total length (TL) increased from 0.57 to 13.18 cm. Primordial germ cells (PGCs) were first detected at 0.68 cm TL (10 dpp). When fish reached 1.52 cm TL (50 dpp), initial stages of ovarian differentiation were identified by the presence of PGCs containing condensed chromatin and their transformation into meiotic oocytes. At 10.23 cm TL (300 dpp), the ovaries gradually developed into oocytes in the primary yolk stages. Ovary growth was rapid after sex differentiation, but testis tissue continued to multiply without growing until fish reached 6.97 cm TL (200 dpp), after which the production of spermatocytes, spermatogonia, and cyst cells was apparent. Histological analysis of gonadal structure suggested a gonochoristic sexual development pathway. Our analysis of the sex ratio at 400 dpp showed a significantly higher proportion of males.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.1
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• pp.44-50
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• 2004

Age and growth of the blue spot mudskipper (Boleophthalmus pectinirostris) were studied using the samples caught in the mud flats of southwestern Korea during April-October, 2001. The value of the marginal index of the second actinost bone was the lowest in July and October and indicated by rings that was analysis of formed teice a year. The relationship between body weigt (BW) and total length (TL) was expressed as BW=0.000005 $TL^{3.12}\;(r^2=0.92)$ for females and BW=0.000476 $TL=^{2.18}\;(r^2=0.62)$ for males. Regression analysis of TL-BW between sexes showed a significant difference (P<0.01). Relationship between total length (TL) and actinost radius (R) were expressed as TL=16.9+33.4 R $(r^2=0.62)$ for females and TL=45.8+26.2 R $(r^2=0.41)$ for males. Growth parameters, $L\infty,t_0$ and K were estimated as 165.2 mm, -0.23, and 1.07 for females and 155.3 mm, -0.35, and 1.39 for males.

• The Journal of Society for e-Business Studies
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• v.12 no.3
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• pp.133-150
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• 2007

In this paper we investigate a trend analysis service using Semantic Web technology in a news domain. The trend analysis service can provide more intelligent answers rather than the answer given In current news search engines since it can analyze the passage of time and the relation among news. In order to provide the trend analysis service, the capability of temporal reasoning is required, but the Semantic Web language such as OWL does not support the reasoning capability. Therefore, we propose a language TL-OWL(Temporal Web Ontology Language) extending OWL with the temporal reasoning.

• Journal of Food Hygiene and Safety
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• v.27 no.3
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• pp.233-246
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• 2012

In this study, we investigated the applicability of the photostimulated luminescence(PSL), thermoluminescence(TL) and electron spin resonance(ESR) methods for various foods which are not allowed to be irradiated in Korea. All 15 foods including sesame, almond, peanut, cocoa powder etc. were analyzed. Samples were irradiated at 1~10 kGy using a $^{60}Co$ gamma-ray irradiator. In PSL study, the photon counts of all the unirradiated samples showed negative(lower than 700). The photon counts irradiated(1 kGy) dried shrimp, roasted peanut and seasoned peanut showed positive(higher than 5,000) and the other samples were negative or intermediate(> 700 and < 5,000). In TL analysis, results showed that it is possible to apply TL method to all foods containing minerals. In ESR measurements, the ESR signal(single-line) intensity of irradiated foods was higher than non-irradiated foods. In particular, the specific ESR signals of irradiation-induced crystalline sugar, cellulose and bone radical were detected in dried plum, raisin, dried cherry, mango(dried, frozen), rambutan, cocoa(powder), cinnamon, parsley, carrot, broccoli, dried arrow squid, dried pollack and dried shrimp. According to the results, PSL, TL and ESR methods were successfully applied to detect the irradiated foods because TL method is not able to detect the irradiated foods rarely composed of minerals. ESR is also a difficult method to detect the changes of ESR signal patterns of food. It is concluded that TL analysis or ESR assay is suitable for detection of irradiated samples and a combined method is recommendable for enhancing the reliability of detection results.

• Journal of Radiation Protection and Research
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• v.41 no.2
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• pp.167-171
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• 2016

Background: TlBr is of considerable technological importance for radiation detection applications where detecting high-energy photons such as X-rays and ${\gamma}$-rays are of prime importance. However, there were few reports on investigating optical properties of TlBr itself for deeper understandings of this material and for making better radiation detection devices. Thus, in this paper, we report on the optical characterizations of TlBr single crystals. Spectroscopic ellipsometry (SE) and photoluminescence (PL) measurements at RT were performed for this work. Materials and Methods: A 2-inch TlBr single crystalline ingot was grown by using the vertical Bridgman furnace. SE measurements were performed at RT within the photon energy range from 1.1 to 6.5 eV. PL measurements were performed at RT by using a home-made PL system equipped with a 266 nm-laser and a spectrometer. Results and Discussion: Dielectric responses from SE analysis were shown to be slightly different among the different samples possibly due to the different structural/optical properties. Also from the PL measurements, it was observed that the peak intensities of the middle samples were significantly higher than those of the other two samples. With the given values for permittivity of free space (${\varepsilon}_0=8.854{\times}10^{-12}F{\cdot}m^{-1}$), thickness (d = 1 mm), and area ($A=10{\times}10mm^2$) of the TlBr sample, capacitances of TlBr were 6.9 pF (at $h{\nu}=3eV$) and 4.4 pF (at $h{\nu}=6eV$), respectively. Conclusion: SE and PL measurement and analysis were performed to characterize TlBr samples from the optical perspective. It was observed that dielectric responses of different TlBr samples were slightly different due to the different material properties. PL measurements showed that the middle sample exhibited much stronger PL emission peaks due to the better material quality. From the SE analysis, optical, dielectric constants were extracted, and calculated capacitances were in the few pF range.