As the importance of radioactive waste management has emerged, quality assurance management of radioactive waste has been legally mandated and the Korea Radioactive Waste Agency (KORAD) established the “Waste Acceptance Criteria for the 1st Phase Disposal Facility of the Wolsong Lowand Intermediate-Level Waste Disposal Center (WAC)”, the detailed guideline for radioactive waste acceptance. Accordingly, the Korea Atomic Energy Research Institute (KAERI) introduced a radioactive waste quality assurance management system and developed detailed procedures for performing the waste packaging and characterization methods suggested in the WAC. In this study, we reviewed the radioactive waste characterization method established by the KAERI to meet the WAC presented by the KORAD. In the WAC, the characterization items for the disposal of radioactive waste were divided into six major categories (general requirements, solidification and immobilization requirements, radiological, physical, chemical, and biological requirements), and each subcategories are shown in detail under the major classification. In order to satisfy the characterization criteria for each detailed item, KAERI divided the procedure into a characterization item performed during the packaging process of radioactive waste, a separate test item, and a characterization item performed after the packaging was completed. Based on the KAERI’s radioactive waste packaging procedure, the procedure for characterization of the above items is summarized as follows. First, during the radioactive waste packaging process, the characterization corresponding to the general requirements (waste type) is performed, such as checking the classification status of the contents and checking whether there are substances unsuitable for disposal, etc. Also, characterization corresponding to the physical requirements is performed by checking the void fraction in waste package and visual confirmation of particulate matter, substances containg free water, ect. In addition, chemical and biological requirements can be characterized by visually confirming that no hazardous chemicals (explosive, flammable, gaseous substances, perishables, infectious substances, etc.) are included during the packaging process, and by taking pictures at each packaging steps. Items for characterization using separate test samples include radiological, physical, and chemical requirements. The detailed items include identification of radionuclide and radioactivity concentration, particulate matter identification test, free water and chelate content measurement tests, etc. Characterization items performing after the packaging is completed include general requirements such as measuring the weight and height of packages and radiological requirements such as measurements of surface dose rate and contamination, etc. All of the above procedures are proceduralized and managed in the radioactive waste quality assurance procedure, and a report including the characterization results is prepared and submitted when requesting acceptance of radioactive waste. The characterization of KAERI’s radioactive waste has been systematically established and progressed under the quality assurance system. In the future, we plan to supplement various items that require further improvement, and through this, we can expect to improve the reliability of radioactive waste management and activate the final disposal of KAERI’s radioactive waste.

In this work, we report test results for direct melting of non-combustible wastes by using a 100 kW class transferred type plasma torch. For this purpose, non-combustible wastes consisting of metals and sands were prepared, weighed and melted by a transferred arc in a ceramic crucible with inner diameter of 150 mm. Test results reveal that 75wt% M6 iron bolts mixed with 25wt% sands were completely melted down within 140 seconds at the plasma power level of 83.8 kW, producing melting speed of 100 kg/hr and volume reduction rate of 62.8%. In addition, for simulated wastes consisting of 77.3wt% metal chips and 22.7wt% sands, the volume reduction rate high than 88% was achieved at 50 kW plasma power. These results indicate that non-combustible wastes can be treated efficiently when directly melting them by using transferred type plasma torch.

It is important that the plasma torch used in the waste treatment field has a high output to increase throughput. In order to increase the output of the plasma torch, there is a method of increasing the current or extending the length of the plasma arc. Among these methods, high power can be easily achieved simply by increasing current, but it is difficult to ensure electrode life. Therefore, it is necessary to check the appropriate current and arc length conditions to achieve high power and stable operation. In this paper, the power performance according to the arc length, current, and operation mode was confirmed in the transfer mode plasma torch. The test conditions are the distance (arc length) between the plasma torch and the external electrode was set to 5-180 mm, and the current was set to be in the range of 90-460 A. As a result of the test, it was confirmed that the reverse polarity operation had a maximum output of 159 kW depending on the arc length and current, and the positive polarity operation had a maximum output of 138 kW. Through this result, it was confirmed that the arc length had an effect on increasing the output, and that the reverse polarity operation had a longer arc than the positive polarity operation.

This study uses first-principles calculations to investigate the mechanical properties and effect of strain on the electronic properties of the 2D material 1H-PbX2 (X: S, Se). Firstly, the stability of the 1H Pb-dichalcogenide structures was evaluated using Born’s criteria. The obtained results show that the 1H-PbS2 material possesses the greatest ideal strength of 3.48 N/m, with 3.68 N/m for 1H-PbSe2 in biaxial strain. In addition, 1H-PbS2 and 1H-PbSe2 are direct semiconductors at equilibrium with band gaps of 2.30 eV and 1.90 eV, respectively. The band gap was investigated and remained almost unchanged under the strain εxx but altered significantly at strains εyy and εbia. At the fracture strain in the biaxial direction (19 %), the band gap of 1H-PbS2 decreases about 60 %, and that of 1H-PbSe2 decreases about 50 %. 1H-PbS2 and 1H-PbSe2 can convert from direct to indirect semiconductor under the strain εyy. Our findings reveal that the two structures have significant potential for application in nanoelectronic devices.

The research on dye-sensitized solar cells (DSSCs) is in the advanced stage today. The only concern observed so far has been regarding its stability and efficiency. Its power conversion efficiency can be increased by incorporating various methods and materials based on nanotechnology. Several attempts have been employed to develop advanced methods for eco-friendly, commercially viable, and sustainable DSSCs to minimize the energy crisis in the future. Photoanode is one of the essential components of DSSCs that can be modified using different nanostructures to enhance its efficiency. The TiO2 nanoparticlebased photoanode with gold and silver has proven to be potent materials for getting efficient DSSCs. The plasmonic and quantum confinement effects also play a vital role in efficiency enhancement. In this review, we discuss numerous attempts made by researchers in the last decade to modify the photoanode and their progress. We also look at different types of nanostructures, such as quantum dots, metal oxide doping, layered structures, nanocomposites, and thin film formation, that improve the efficiency of DSSCs. Several methods were reviewed to modify photoanodes to optimize electron transportation, light scattering, trapping power, surface area, and reduce charge recombination. The trend in the efficiency enhancement of DSSCs using TiO2, Au, ZnO, Ag, and graphene nanostructures-based photoanodes have been explored in great detail.

Subunit vaccines are being developed as a potential therapy for preventing microbial pathogen infection. In this study, the immunogenicity of recombinant Brucella (B.) abortus Fe/Mn superoxide dismutase (rFe/Mn SOD) protein as a subunit vaccine against B. abortus was investigated in BALB/c mice model. Brucella Fe/Mn SOD gene was cloned into a pcold-TF DNA vector. The bacterial recombinant protein was expressed using the Escherichia coli DH5α strain with a size of 82.50 kDa. The western blotting assay showed that rFe/Mn SOD reacted with Brucella-positive serum, indicating the potential immunoreactivity of this recombinant protein. After the second and third vaccinations, the peripheral CD4+ T cell population was increased significantly in the rFe/Mn SOD-immunized mice group compared to the PBS control group. Moreover, immunization of this recombinant protein increased the CD4+ T cell population from the first vaccination to the third vaccination. Meanwhile, the CD8+ T cells were slightly enhanced after the second vaccination compared to the first vaccination and compared to control groups. Fourteen days after the bacterial infection, the splenomegaly and the number of bacteria in the spleen were evaluated. The result showed that both rFe/Mn SOD and positive control RB51 decreased the bacterial replication in the spleen and the splenomegaly compared to control groups. Altogether, these results suggested that rFe/Mn SOD could induce host immunity against B. abortus infection.

존재의 정체성은 지속적으로 성장하여 지고의 의식을 분출하고 감싸고 그것의 일부가 된다. 그럼에도 불구하고 그러한 노력은 현상 세계의 실증된 경험이 초래하는 모순과 분열을 정복하고 극복할 수 있는 강하고 단호한 의지를 예상하고 전제한다. 우파니샤드는 비이원성과 이원성을 번성하는 절대자의 형태로 이 문제에 대한 견해를 제시한다. 우리가 살고 있는 세상은 동일한 절대자의 창조적 본능과 창조적 의지의 결과이다. 따라서 정확히 세계 그 자체인 시초가 있지만 지고의 종말이 있으며, 시초부터 종말까지의 움직임이나 진행은 때때로 현전의 방식에서 그러하듯이 명백히 어려움을 겪으며, 다른 경우에는 확인된 부재로 성취된다. 그 정도에 이르기까지 끈기, 인내, 추측, 명상 등의 상태가 존재한다. 사무엘 베켓의 예술적 기교에서 그러한 상황을 다루는 방식은 그의 소설과 드라마에서 등장인물, 상황, 행동, 사건 및 관계가 이 세상의 모순과 다양성을 표현하는 것에서 잘 드러난다. 한편 등장인물들은 압도되는 모습을 보이며, 부재하는 초월적인 것에서 안도감을 찾는다. 실제와 외견은 모순되고 실제는 이해의 필요성에 따라 확장된다. 우파니샤드는 그러한 상황을 이해하는 하나의 틀이 될 수 있는데, 베켓은 그러한 신념체계를 지속적으로 드러낸다.

This research will examine how the Indonesian constitution can effectively protect the indigenous people’s rights to customary land when the land is under construction for infrastructure building. The authors will mainly discuss the relevance of justice for ensuring the rights to live and property of indigenous people under the Indonesian constitution. In this essay, the authors examine how constitutional and human rights protections interact with one another to ensure the security of customary land in Indonesia. The analysis will be carried out by two methodological approaches. One is the statute approach which is based on laws and regulations being specifically targeted. To implement the statutory approach, all Indonesian laws and regulations concerning the constitutional relationship and human rights to protect customary land will be reviewed. The other is the conceptual approach to identify the ideas that give rise to legal notions, the legal principles or legal arguments for solving the problem.

Enhancing the capacitive deionization performance requires the inner structure expansion of porous activated carbon to facilitate the charge storage and electrolyte penetration. This work aimed to modify the porosity of coconut-shell activated carbon (AC) through CO2 activation at high temperature. The electrochemical performance of CO2- activated AC electrodes was evaluated by cyclic voltammetry, charge/discharge test and electrochemical impedance spectroscopy, which exhibited that AC-800 had the superior performance with the highest capacitance of 112 F/g at the rate of 0.1 A/g and could operate for up to 4000 cycles. Furthermore, in the capacitive deionization, AC-800 showed salt removal of 9.15 mg/g with a high absorption rate of 2.8 mg/g min and Ni(II) removal of 5.32 mg/g with a rate close to 1 mg/g.min. The results promote the potential application of CO2- activated AC for desalination as well as Ni-removal through capacitance deionization (CDI) technology.

In the present work, a three-phase AC arc plasma torch system is proposed to separate inorganic radioactive materials from the organic liquid waste. For this purpose, first, assuming the resistance of arc plasma ranges between 0.1 and 0.2 ohm, we designed a three-phase AC arc plasma power supply with the power level of 20 kW. Then, a three phase arc plasma torch consisting of three carbon rods with the diameter of 20 mm was designed and mounted on a cylindrical combustion chamber with the inner diameter of 150 mm. Detail design and basic performance of the plasma system were presented and discussed for application to the treatment of radioactive slurry wastes.

In this work, we report the basic performance of a 100 kW class mobile plasma melting system consisting of two 24-ft commercial containers, each in charge of the plasma utilities and melting process. In this system, a 100 kW class transferred type plasma torch has been installed together with a crucible having an inner volume of 2,884 cm3. Filling the inner volume of the crucible with the simulated metal waste, such as bolts and nuts, melting tests have been carried out for 5 min by varying plasma input power from 50 kW to 100 kW. By measuring the volume of metal waste before and after melting test, then, the volume reduction rates were estimated and discussed.

We developed a 100 kW Class Transferred Type Plasma Torch applicable for melting of noncombustible metal wastes. By employing reverse polarity discharge structures for hollow electrode plasma torch, a transferred type arc plasma was generated stably with long arc length higher than 10 cm at the arc currents of ~400 A and gas (N2) flow rate of ~50 lpm. High arc currents and high arc voltages caused by the increased arc length could input high power level of ~100 kW to the noncombustible metal wastes, enabling quick melting. In addition, relatively long arc length and low gas flow rates can help reduce the deposition of melted materials on the exit surface of the torch. Thanks to these features, the developed plasma torch is expected to be suitable for small-scaled and portable melting system.

Chlorine dioxide (ClO2) has recently emerged as an ideal disinfectant and has shown a wide range of antimicrobial activities in various pathogenic microorganisms. In this study, the virucidal effect of ClO2 at low concentration (0.02 ppm) and higher concentration (0.06 – 0.09 ppm) against Adenovirus and Herpesvirus was evaluated based on the NF T 72-281 and ASTM 1053-11 standard methods at different exposure times. The virus suspension was dried onto the carrier and then exposed to gaseous ClO2 (gClO2) at 22 ± 2∘C. For Adenovirus, exposure at a low concentration of ClO2 at the middle height resulted in the average log10 reduction of 0.95, 2.65, and 5.30 after 1, 3, and 6 h post-exposure (pe), respectively. Moreover, more than 4-log10 reduction was achieved at 4 and 6 h pe with higher concentrations of ClO2. On the other hand, the antiviral activity of gClO2 at the middle height was also effective against Herpesvirus. In particular, at 1 h pe, a less than 4-log10 reduction was observed at all examined concentrations of ClO2, whereas exposure for 3 and 6 h (with low concentration) or 2 h (with higher concentration) inactivated completely viruses attached to the carrier. These results suggested that ClO2 fumigation is a potential alternative method for disinfecting healthcare facilities, high-containment laboratories, and households with a safe concentration for human health.