• The Korean Journal of Food & Health Convergence
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• v.7 no.4
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• pp.13-21
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• 2021

The goal of this study was to quantify the content of heavy metals (Zn, Cu, Cd, Pb, Hg) in the bivalve Mytilus galloprovincialis, which was obtained from the Black Sea's Sinop peninsula, as well as estimate the health risks. Concentrations of heavy metals in mussels' soft tissues ranged between 16.4-21.8, 0.52-0.93, 0.13-0.45; 0.015-0.019 and 0.006-0.011mg kg^-1 wet weight for Zn, Cu, Pb, Hg and Cd, respectively. In general, metal concentrations in mussels were quite low. In mussels, Zn was the most prevalent element, followed by Cu. Regarding the monthly variation, although relatively higher tissue metal concentrations were observed in August compared to July, no statistical difference was found. The estimated daily intakes did not exceed the tolerable intakes. There was no health risk since the total hazard index was far below critical value 1. This demonstrates that eating mussels from the Sinop coasts in 2019 does not cause any health risks in infants, children, or adult. Mussels have a risk index of less than 10^-6, which is considered insignificant. In conclusion, the results of this study show that there is no heavy metal pollution in the mussels collected from Sinop coasts.

• The Korean Journal of Food & Health Convergence
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• v.6 no.1
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• pp.21-27
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• 2020

The levels of five heavy metals (mercury, cadmium, lead, copper and zinc) were analyzed in edible tissues of Lophius piscatorius Linnaeus, 1758 marketed in Sinop coasts of the Black Sea by using inductively coupled plasma mass spectrometry. With the present study, heavy metal values of this fish in the Black Sea were examined for the first time. The mean concentrations in mg kg^-1 wet wt. of Hg, Cd, Pb, Cu and Zn were 0.022, 0.009, 0.035, 6.3 and 16 mg kg^-1 wet wt., respectively. The results of the present study indicate that the consumption of muscle from anglerfish can be considered safe in terms of permissible legal limits. It is clear that, Zn showed the high accumulation in muscle tissue followed by Cu, while non-essential metals Hg, Cd and Pb showed the low accumulation. This could be explained by the fact that Zn and Cu are essential elements in the bodies of living organisms and has an important role in different physiological processes. In the present study, heavy metal levels in angler fish were low. Likewise, the calculated HI values were lower than one. In conclusion, the results of the present study indicate that the consumption of muscle from anglerfish can be considered safe in terms of permissible legal limits and hazard index values.

• Nuclear Engineering and Technology
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• v.55 no.12
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• pp.4664-4670
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• 2023

Radiation is the main safety issue for almost all nuclear applications, which must be controlled to protect living organisms and the surrounding materials. In this context, radiation shielding materials have been investigated and used in nuclear technologies. The choice of materials depends on the radiation usage area, type, and energy. Polymer materials are preferred in radiation shielding applications due to their superior characteristics such as chemical inertness, resistivity, low weight, flexibility, strength, and low cost. In the presented work, ABS polymer material, which is possibly the most commonly used material in 3D printers, is mixed with Gd₂O₃ and Er₂O₃ nanoparticles. ABS filaments containing these rare-earth elements are then produced using a filament extruder. These produced filaments are used in a 3D printer to create shielding samples. Following the production of shielding samples, SEM, EDS, and gamma-ray shielding analyses (including experiments, WinXCOM, GEANT4, and FLUKA) are performed. The results show that 3D printing technology offers significant enhancements in creating homogeneous and well-structured materials that can be effectively used in gamma-ray shielding applications.

• Nuclear Engineering and Technology
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• v.56 no.6
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• pp.1943-1949
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• 2024

This study focuses on the comparative analysis of ABS polymer samples produced using two distinct manufacturing techniques: 3D printing and the sol-gel methods. In the first approach, ABS polymer was augmented with rare earth oxides, Er₂O₃ and Gd₂O₃, in nano powder form and fabricated into test specimens using 3D printing technology. In the second approach, identical samples were prepared via the sol-gel technique involving mold-based fabrication. Elemental content analysis revealed no significant differences between the samples produced by the two methods. The study proceeds to evaluate the gamma-ray shielding, neutron shielding, temperature resistance, and SEM/EDS pictures of ABS samples generated through both techniques. 3D printing method exhibited more favorable results in terms of structure morphology and thermal stability while there is no significant difference for radiation shielding. The results provide insights into the performance and suitability of each production method for radiation shielding applications. This research not only contributes to enhancing radiation shielding technology but also informs the selection of the most appropriate fabrication method for specific applications in nuclear technologies and diagnostic energy range in medical purposes.

• The Korean Journal of Food & Health Convergence
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• v.4 no.3
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• pp.22-31
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• 2018

In this present work, the amounts of toxic elements were determined in the soft tissues of mollusks (Mytilus galloprovincialis and Rapana venosa) collected from Igneada shores of the Black Sea where suggested as Marine Protection Area (MPA). M. galloprovincialis accumulated the highest amounts of Cd in winter, while the highest amounts of Cd and Hg were detected in R. venosa in winter and autumn. The concentrations of toxic elements found in the soft tissues of mollusks varied for Cd: 0.07-0.14, Hg: 0.03-0.44 and Pb: 0.09-0.21 mg/g dry wt. The estimated levels of all non-essential metals in the present work were lower than the limits permitted by European Community Regulation (EU) and the Turkish Food Codex (TFC). The estimated weekly intakes (EWI) and daily intakes (EDI) of all the through consumption of these seafood by Turkish people in the Igneada coasts of the Black Sea were quite below the permissible tolerable weekly/daily intakes for 70 kg person (PTWI / PTDI) set by FAO/WHO. As results, it can be concluded that no hazard effects on people health would be raised at present from the consumption of these mollusks' species.

• Bulletin of the Korean Mathematical Society
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• v.47 no.4
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• pp.825-837
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• 2010

In this paper, we obtain a Korovkin type approximation theorem for double sequences of positive linear operators of two variables from $H_w$ (K) to C (K) via A-statistical convergence. Also, we construct an example such that our new approximation result works but its classical case does not work. Furthermore, we study the rates of A-statistical convergence by means of the modulus of continuity.

• Nuclear Engineering and Technology
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• v.56 no.7
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• pp.2625-2632
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• 2024

In this study, we investigated the possibility of employing accident tolerant fuel (ATF) in VVER-1200/V491 assembly without gadolinium-containing fuel rods using the Monte Carlo code Serpent 1.1.7 with ENDF/B-VII cross-section library. The analysis involves assembly design with reflective boundary conditions. To compare the neutronic performances, U-5Mo, U-7.5Mo, U-10Mo, and U-15Mo fuels were chosen in addition to ordinary UO₂ fuel. The concentration of ¹³⁵Xe, ¹⁴⁹Sm, fissile and fertile isotopes with burnup, reactivity feedback with fuel temperature variation, and β eff values were calculated. The results indicate that the fuel cycle length increases by 54.27% for U-5Mo, 32.6% for U-7.5Mo, and 13.8% for U-10Mo, while it decreases by 16.4% for U-15Mo fuel. Additionally, the effect of ⁹⁵Mo content in natural Mo was investigated by reducing the ⁹⁵Mo concentration. According to the results, each proposed fuel's fuel cycle length extended when the depletion ratio of ⁹⁵Mo increased. Additionally, the calculations for reactivity feedback guarantee safe operating conditions for all U-xMo fuels.

• Communications of the Korean Mathematical Society
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• v.23 no.3
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• pp.427-446
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• 2008

In this paper, we give some new definitions of compatible mappings in intuitionistic fuzzy metric spaces and we prove a common fixed point theorem for four mappings under the condition of compatible mappings of type (I) and of type (II) in complete intuitionistic fuzzy metric spaces.

• Communications of the Korean Mathematical Society
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• v.24 no.4
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• pp.565-579
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• 2009

In this paper, we give some new fixed point theorems for contractive type mappings in intuitionistic fuzzy metric spaces. We improve and generalize the well-known fixed point theorems of Banach [4] and Edelstein [8] in intuitionistic fuzzy metric spaces. Our main results are intuitionistic fuzzy version of Fang's results [10]. Further, we obtain some applications to validate our main results to product spaces.

• Korean Journal of Mathematics
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• v.29 no.3
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• pp.581-591
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• 2021

In this paper, we discuss and investigate the existence of the inclusion L^p(.),𝜃 (𝜇) ⊆ L^q(.),𝜃 (𝜈), where 𝜇 and 𝜈 are two finite measures on (X, Σ). Moreover, we show that the generalized variable exponent grand Lebesgue space L^p(.),𝜃 (Ω) has a potential-type approximate identity, where Ω is a bounded open subset of ℝ^d.